Portal 2/Headscratchers

Old Test Shaft Construction Timeline

 * After Wheatley throws Chell and Potat OS down the shaft, we start to encounter dates painted on the walls; presumably these are the construction dates for various parts of the old facility. The abandonment hatch to Test Shaft 09 Zulu Bunsen is dated 06 15 1961. The area just beyond that, with the foyer and the elevator tower, is dated 1952. The first three test spheres are dated 1953, 1957, and 1958, respectively. So far, so good. But Pump Station Beta is dated 1971, ten years after the shaft was supposedly abandoned. Spheres 4 and 5 are dated 1972 and 1976. Immediately after exiting Sphere 5, you're looking at a wall marked 1978. Pump Station Gamma is dated 1982, while the offices immediately after are dated 1981. Sphere 6 has two dates on different parts of the interior wall surrounding the conversion gel pipe, 1982 and 1986; one assumes the four-year construction time for the relatively simple test area was due to Aperture's financial difficulties. If the shaft was abandoned in June of 1961, why was Aperture still constructing test chambers in it at least twenty-five years later?
 * They abandoned it in the 1960's, then reopened it in the 70's. Probably looking looking for a hidden place to continue with the testing.
 * It is odd, but I assume that only the bottom levels were abandoned, and they kept moving up after filling too many side labs with concrete.

Wheatley and Cave

 * This is a speculation thrown into the void, but has anyone else drawn notable comparisons between Cave Johnson and Wheatley? Hearing his soliloquy at the end when he is stranded in space, it occurred to me that apologising for being "monstrous" and "bossy" was the kind of thing Cave might have said to Caroline "if he were ever to see her again". Endless stream of terrible ideas? Disregard for human life for the cause of science? Perhaps some remnant of Cave ended up in Wheatley via a wayward attempt at brain mapping?

Wheatley and Spanish

 * When Wheatley takes over GLaDOS' body, he spouts a bunch of Spanish saying that he's doing something wrong and to consult the manual, and follows it up with "I don't even know what I just said!" Which would imply that he doesn't speak Spanish, which is perfectly reasonable, except for the fact that if you hang around in the Relaxation Chamber for long enough, he asks you to open the door in perfectly good Spanish. What gives?
 * He only knows a certain amount of Spanish? All he says at the door is a very stilted and badly accented "Hola, amigo, abre la puerta" compared to the longer and much more fluid sentence when he takes over GLaDOS' body (maybe to show he's still at the same intelligence either way)...
 * You can parrot words without understanding what they mean.

Both sides vote on Stalemate Resolution

 * Something that bugged me regarding the Stalemate Resolution Button: why does the corrupted core get a choice? Aperture being Aperture again?
 * You said it. Also, I guess the designers thought there might be something the corrupted core is doing to keep the facility from being destroyed, so despite its evil intentions, it may be safer to leave it in place. A qualified Stalemate Associate would know whether to let the corrupted core go on keeping the facility from exploding or switch it out with an uncorrupted and (presumably) equally competent core. Look at what Wheatley did when he was left in charge. Maybe someone with full knowledge of all the complex operations required to keep the facility running (and of Wheatley's status as "the product of the greatest minds of a generation working together with the express purpose of building the dumbest moron who ever lived") might have actually made a different decision. Except, you know, GLaDOS killed them all.

Sound in space

 * How could Wheatley hear the Space Core talking? Sound doesn't travel in space.
 * Space Is Noisy.
 * Or built-in short-range radio transmitters.
 * The moon does have an atmosphere, albeit extremely thin. Maybe he was just REALLY loud.
 * Or, you know, the huge amount of air that accompanied them.
 * No, because that "huge" amount of air is laughably tiny in the vast expanse of space and will quickly dissipate.
 * You're assuming normal science will stand up in the face of Aperture Science...
 * And if you go by that logic, why bother WMG-ing at all? Just dismiss everything as being Aperture Science and not think about it, which is counter to the point of headscratchers. You can't have it both ways. It may be gonzo fictional science, but it still has limits.

Portals invented after the Combine invade?

 * On the Aperture website (or perhaps it's the Combine Overwiki), it says that Aperture lost the race to be the first to invent working portal technology when Black Mesa opened their interdimensional portal to the Combine. But in the boots video, which is before Cave Johnson's death as evidenced by his voiceover, we see Chell using the ASHPD while testing the boots. Presumably this took place before the Combine invaded. So how..?
 * It's not canon. It's just a promotional piece released by Valve. That said, the timeline is rather messed up, and they were horrible at marketing their products.
 * Nonono. Aperture lost the race to invent interdimensional portal technology. Their intradimensional quantum-tunneling device was useful, but dangerous and often sent you through time as well as space--hence why they spent so long testing it.

Leaving and returning to GLaDOS

 * When we first left GLaDOS chamber, how did we get back? First we fell down. Then there were tests, and each lift was taking us down. Again! And then we escaped, found some tube, and got back. Where all the miles went?
 * We don't know how long Chell was in the tube, and most of what we can see, she's going back up. Additionally, notice that the room GLaDOS was reactivated in is completely overrun, while the room where the stalemate takes place is fairly clean and tidy; it's possible that, like the rest of the facility, GLaDOS can move her "body" around, and the stalemate happens in another room entirely.
 * While it's possible that those are different rooms (the room with the Stalemate Resolution Button doesn't have the incinerator, nor does GLaDOS use the crane claws in it), the room where the core transfer takes place is apparently the same one where you fight Wheatley at the end, and that one is near the surface. But even if all the elevators go down, the most likely explanation for me seems to be that Chell traveled a long distance up in that tube during a loading screen.
 * The second time you encounter GLaDOS could take place in the same room as when you first woke her up. Over the course of the game, as you're moving from test chamber to test chamber, GLaDOS is cleaning up the Enrichment Center. It could be that while she was fixing the dilapidated test chambers, she was also moving around panels and whatnot in her room, including the incinerator.

Architecture of the facility

 * One thing that kinda bugs me is this: In the original Portal, the Aperture Science Facility seems to be a normal building (solid, in other words, and in no way, shape, or form, mix and matchable). However, in the sequel, we see that it is, more or less, a giant collection of disconnected rooms that can be moved at random, to fit whatever GLaDOS or whoever chooses. If this is the case, then why is it we were able to go through the back rooms, air ducts, and such in the original at all, when the giant test chambers are, in fact, completely disconnected from each other and movable? Even ignoring the fact that these disconnected pieces shouldn't even be able to have these air ducts and back rooms, I'm left asking this: Does Portal 1 take place in an old part of the facility that wasn't inspired by Lego, or was lovable old Wheatley actually doing something to GLaDOS in the first game that made her forget that she could, at any moment, take the air duct/behind the scenes area/back room part of whatever puzzle piece I so happened to be in and drop it into the void that apparently exists beneath Aperture Science? Doesn't change how much I love both games, I'm just curious as to if there is an official explanation for how the void and Stickle Brick test chambers can exist and not exist in, apparently, the exact same location in the facility.
 * The Enrichment Centre is the oldest part of the facility. Possibly as old as the Aperture Gel Caves, but most certainly the oldest chambers GLaDOS has any control over. She sends Chell through these chambers because they're the most basic tutorial chambers and testing obsession requires her to follow the protocol. The facility is physically static and lacks the state-of-art technology of the rest of Aperture facilities which is why Rattmann is capable of hacking/breaking parts of it to create the dens where he lives, while being able to evade relatively little presence GLaDOS has there. This is further supported by Portal 2 where the old/top chambers are the only ones that are really ruined, trashed and overgrown. While GLaDOS seems to have started to upgrade those with some of the shifting/rebuilding tech while she was still alive in Portal (we just never had a chance to see the upgraded part of the facility in the original game), the best she can do with the arms is clean the place from most of the rubbish as opposed to say, just rebuilding the chambers from scratch meaning that ultimately the place is still rooted in the same layout.
 * As this responder said, the Rattman dens are usually hidden in said back rooms/etc. (The first one you come across is in a back room, with the panel being held open by two cubes.) However, Chell wouldn't have been able to find a way to access any of these back rooms on her own, so GLaDOS didn't really worry about it.

Fat turrets

 * During the ending chorus of turrets, why do the fatter and giant turrets exist? There isn't much purpose for them. The giant one COULD be a product, because they saw their announcement about apocalyptic circumstances were one feature, and thought "Why not?", but why a fat turret with exactly the same size guns?
 * Larger ammo capacity. Note how the turrets are designed. The entire body is storage.
 * To hold more bullets as evident in the "Turrets" trailer. Their simplistic constructions means expanding ammo capacity is exactly the same as making a bigger turret.
 * Specifically, if you notice early on in the first act, there's a graphic of the giant turret killing an entire room full of creatures. I say creatures rather than people because the graphic is preceded by a voice-over talking about precautions made for the event of a race of intelligent animals enslaving mankind, and the graphic is titled "Animal Takeover."
 * That doesn't explain you calling the people "creatures".
 * Alternately, a pun of "It's not over until the fat lady sings".
 * Or...I noticed in the co-op game, in the last level, there are a few turrets that seem to do significantly more damage; I got killed in only one or two hits, whereas it previously took nearly a dozen hits to kill me. And I never got a good look at them. When I finished the single-player mode, and saw the fat turret, I assumed it was one of the "heavy turrets" that had been at the end of the co-op mode.
 * The turrets at the end of co-op are reskinned normal turrets. They don't do more damage, there's just more of them and they're positioned to knock you into pits.

GLaDOS and Caroline

 * GLaDOS deleting Caroline seems rather counter-productive if GLaDOS is Caroline. And the more GLaDOS becomes her former self/Caroline, the less likely she should want to wipe her Caroline persona out. The game's purposely being really vague on the details of this subplot, so did the ARG provide any better explanations as to how much of GLaDOS is AI vs Caroline?
 * I think although Caroline was originally GLaDOS, years of endless testing caused her to forget her original motive. Thus, Caroline became a different personality, which she remembered. Specifically, Caroline appears to be nicer and generally more human, whereas GLaDOS is more cold and calculating. Indeed, if you pay attention, you can actually hear a difference when she deletes Caroline. Before, it has a bit of happiness to it, whereas GLaDOS is more monotone and cold.
 * There's also the fact that the technology to upload brains into computers in the first place (which is apparently how Caroline became GLaDOS) was created by Aperture Science under the direct instruction of an increasingly deranged Cave Johnson. GLaDOS is not necessarily just a brainscan of Caroline, it could be a fully sentient AI that happened to have Caroline's memories added to it (like a secondary personality core or something).
 * As seen with the Lab Rat comic done by Valve, GLaDOS tried to kill all of the scientists in the facility within one sixteenth of a picosecond after being turned on. That doesn't sound like something Caroline would do. Because the artificial consciousness designed by Aperture Science was so badly created, it is unlikely that much of Caroline's personality superseded the self-aware machinations of GLaDOS's computer brain.
 * Johnson gave the order to not let Caroline say 'no' to taking over and uploading her mind to the mainframe after he died. Maybe the scientists, probably as insane as Johnson by that point, didn't take 'no' for an answer. Wouldn't you be a little pissed? Obviously, while Caroline probably felt bad after the fact, the immediate urge to get revenge would have been enhanced by the computer.
 * Why do people assume GLaDOS was telling the truth about this? "Now little Caroline is in here too."
 * GLaDOS isn't the one who said it, though. It was the neutral male robot voice.
 * She can make the speakers say anything, remember the phone call to Chell's parents, and when she uses train sounds to "startle" you?...
 * Considering Wheatley got into power mad crazy mode the moment he was connected to the mainframe, while GLaDOS reverted to being fairly pleasant, maybe the problem is not the AI itself, but something in the mainframe/GLaDOS main body. At least there seems to be some weird subroutines about testing stuff in it.
 * Perhaps GLaDOS pretended to delete Caroline in order to discourage Chell from returning to the Enrichment Center. Part of the Italian song at the end translates to "Why don't you stay away from science?" GLaDOS may have been trying to protect Chell from her built-in compulsion to keep experimenting. This especially makes sense if you subscribe to the "Chell is Caroline's daughter" theory.
 * There's also the fact that GLaDOS
 * There's far more evidence to show that Caroline and GLaDOS are in fact separate than Caroline becoming GLaDOS. For instance, their personalities are completely different, even when GLaDOS turns good. And GLaDOS herself always indicates that she and Caroline are separate, even saying so in the ending song. Her comment "being Caroline taught me a valuable lesson" was basically a way of blaming Caroline for her character development, since Caroline's presence was so strong in the potato that GLaDOS had no choice but to feel Caroline's emotions - basically a different version of the phrase "walk a mile in another's shoes". My theory is that GLaDOS actually was sentient before Caroline's upload, but was unable to communicate it. When Caroline was uploaded, GLaDOS became angry and pushed her back, so Caroline went into a kind of coma until the potato incident (that does explain the chapter title "The Reunion" after all - GLaDOS reunites with Caroline). Ellen McLain herself even says "I think GLaDOS likes Caroline" (no, not in a CaraDOS shipping kind of way), giving further indication that they're separate.

GLaDOS regaining control after the Stalemate Resolution failed

 * Considering the stalemate button blow up in Chell's face before it's activated, what caused GLaDOS to be be plugged back in the mainframe while Wheatley and Chell had a little trip on the moon?
 * But how do you know it wasn't activated? Wheatley's "original function" justifies the idea that his trap fails, and the button gets turned on.
 * Who's to say that the button didn't have an automatic toggle in the event it is destroyed by a corrupted and insane AI? (in other words, breaking the button is same as turning it on)
 * Since Wheatley left the facility, GLaDOS won the argument by default.
 * While still being hooked to the mainframe?
 * Yeah, he was, uh, slightly distracted by the vacuum, and GLaDOS took the opportunity to hack in and make the system think the stalemate had already been resolved - Retconjuration on the mechanical scale.
 * Remember, according to the facility's BSOD, all GLaDOS had to do was press a key.
 * For that matter, who closes the moon portal after GLaDOS pulls Chell back in?
 * GLaDOS - It's not much of a stretch to think that either she uses a wireless function or something to make it shoot the blue portal anywhere already portal-able. Heck, once she was back in control, she could have used panels to make a portal-able wall anywhere she wanted - she didn't really even need to aim it at all!
 * GLaDOS specifically says "She took care of everything." Considering passing through an Emancipation Grill deactivates portals, it could very well be that she set up a grill on the hole (or something similar) to cause the portal to close. Or, simply, turn on the sprinklers.
 * GLaDOS almost certainly just washed off the Conversion Gel that made the Earthside portal possible.
 * Portals stick to surfaces, even after the Conversion Gel gets washed off.
 * GLaDOS is shown in both games to be capable of opening and closing portals without the need for an ASHPD, even the second tests in both games have them being computer-generated on specific walls. Presumably she hacked the password while Wheatley was at the moon, then when Chell was earthside again, just sent a killcode to the portal-closing technology.

Funding

 * Aperture Science is a company who makes Umbrella Corp looks like the ultimate shiniest paragon of sanity. At the same time, they have achieved a tech level so staggering it's making the goddamn Combines looks like space cavemen. I mean, even Tony Stark achievements IN A CAVE!!! looks like child play compare to them. They have an "enrichment center" so mind-bogglingly huge, one could fit the whole Black Mesa center inside it three time over, and it's 100% underground. Point being, where does Cave Johnson get his money, especially considering that pretty much every attempt at selling their stuff ended up with more and more lawsuits?
 * Cave Johnson became a billionaire selling shower curtains to the US Navy. Seriously, that's what Aperture Science was founded to do. If it can make Johnson personally a billionaire, Aperture Science itself must've been significantly richer. Also for a while, they were getting government contracts to research all kinds of crazy stuff. After all, they've had portal technology since the 70s going by Portal 2's single player.
 * All that stuff about shower-curtains was almost certainly non-canon though, it was more of a gag, and wasn't actually IN either game. And I think they had portal technology since the 50s.
 * Umm, non-canon, or a cover-story? If Aperture did create the portal device in the 50s, then the shower-curtain stuff is obviously wrong. Come to think of it, I always thought it was too ridiculous of an origin story, even for Aperture. But now you might as well ask what the hell Cave wanted to find by overtesting a fully viable and exceptionnaly stable technology. I mean, outside of the obvious miniaturization, why did they tested the portal gun for a whooping fifty years for?
 * Because it most likely wasn't stable until shortly before GLaDOS was turned on. You could imagine how many athletes/astronauts/hobos/scientists sped into a portal only to never come out. I also think there was a lot of other data being collected. For example, if a laser goes through a portal, does it lose any power? What about bullets? Do you get any momentum change based on the mass of the object? The tests aren't just for Chell, GLaDOS is testing the latest iteration of the portal gun through a massive number of circumstances in her own insane way. Personal theory is that the moon trick was actually planned. You know that would be awesome for the military.
 * We know it wasn't stable. Cave at one point says that it can mess with the fabric of time, and that if you make eye contact with your past and future self, you could wipe out time. So yeah, testing would have been a pretty good idea.
 * Non-canon? The original cave labs are filled with awards for Cave Johnson's excellent sales career in shower curtains.
 * What were they testing for? The gun warps the fabric of reality. I'd imagine there'd be a number of testable connotations that come attached with that sort of thing, some of which are mentioned above, not least of all Health & Safety.
 * Companies diversify and shift focus all the time. To take one example off the top of my head, the company which produced the Colecovision video game console started off as a shoe leather company before going into paddling pools before finally ending up with video games and the Cabbage Patch Doll -- not exactly a path you'd expect looking at the company when it first started (and now I think about it, this could even be some kind of reference). Put simply, Cave Johnson could have made his fortune making shower curtains -- a fairly cheap and easily-made product which was in heavy demand in the 1950s -- before moving into his true passion (throwing Science! at the wall and seeing what stuck) once he had sufficient capital, funding and government connections (thanks to the shower curtains).
 * Hell, Nintendo started making card games before shifting its focus to taxi-cabs and Love Hotels. Aperture starting as a shower curtain company doesn't seem so ridiculous.

Portal speed

 * Not so much IJBM as "I want to get this straight", how fast would a portal fired - because you have to fire a portal - reach the moon? Would it be able to hit the moon in that short amount of time it took in the game (a few seconds)? (I'm currently trying to calculate the physics of this to see if it checks, but I'm only in first-level, so I'm not too good at this.)
 * From what I have found, minimum distance between the earth and the moon is approximately 356,400 km. That would mean that light would take about 1.18800 seconds to travel there. The maximum distance is approximately 406,700 km, which would take light about 1.35566 seconds to travel. The question then comes down to how fast the portal travels when fired. It wouldn't be too far-fetched for them to travel as fast as the speed of light, though even traveling at a modestly slower speed would allow it to reach the moon in a matter of a few seconds.
 * Ah, okay then. Another question would be whether gravity affects the shots, but like you said, it probably wouldn't affect it too much.
 * Provided the shots weight something at all, as long as they go faster than the speed required for an object to free itself from Earth gravity (can't remember right now how much), it should be fine.
 * It's quite clear the shots don't weigh anything - otherwise you would constantly be having to take ballistics into account when playing through the game.
 * The commentary specifically states that the shot takes 1.4 seconds, exactly the speed of light transit time (well, close enough with rounding). They were considering making it instantaneous because playtesters would take the shot and then assume that nothing happened, but they settled on the better solution of starting the cutscene mode the instant you pull the trigger. Think about that attention to detail for a moment, in a game that runs on Rule of Funny. It's kind of amazing.
 * Another Headscratcher here: if they put that much work into making it right, and the portals travel at the speed of light, how can you SEE the portal right as it arrives at the moon? Shouldn't you have to wait another 1.4 seconds for the light to reflect and reach your eyes?
 * That twinkle isn't the portal reaching the moon, since otherwise you would have been sucked in right as you see it. I assumed the twinkle wasn't really there, the game was just taunting you.
 * Actually, if the shot takes 1.4 seconds, then the delay for the twinkle to come back is accounted for; if you look at videos on YouTube, it takes just under three seconds to see the twinkle after you fire. The not-sucking-in-immediately part can be chalked up to Rule of Perception.
 * I must note, though, that you wait until after seeing the portal to be sucked in. If true physics were in play, you would fire the portal, and be flying through the air to the portal BEFORE you see it. Also, does anyone know the physics of massive vacuums, and can explain if video games portray vacuums accurately?
 * Here's the sequence of events: Chell fires blue portal at the moon. 1.4 seconds later, the portal arrives and begins to open. The wormhole now propagates back across space at the speed of light, as does the light from the portal opening (must have been really bright). 1.4 seconds later, you see the twinkle. At the same time, the wormhole reaches its destination and connects to the orange portal. The wormhole widens to fit the portal (you can actually see this if you watch a disconnected portal as you fire the connecting one) over a few moments. Finally, the air rushes to fill the low pressure zone on the other side of the portal, producing massive wind. Whether such a small aperture could produce enough wind to pull a person and detach a core is not something I can calculate.

Wheatley: stupid or brilliant?

 * If Wheatley's supposed to be so stupid, then how can he be so clever? First, a dumb person wouldn't have even thought of using the portal gun to escape or even react quickly when he found out that the power went out. There's also that part where he interrupts GLaDOS's test to save you. That was very clever. And what about the part with him watching Chell kill GLaDOS and planning accordingly? He didn't even TELL you he booby trapped the stalemate button. Plus, he changed a jump pad to go in the wrong direction so he can trap you. Seriously, if he was the product of the greatest minds trying to create the most idiotic thing ever, how can he be so smart?
 * He was hooked up to the main frame, which probably increased his intelligence.
 * Alternatively, his bad idea was trying to win. If he won, he couldn't survive the collapse of the facility.
 * It seems to me that ultimately, Wheatley wasn't actually actively stupid. Poor decision maker? Yes. Occasionally thick-headed? Yeah. But he's still capable of stringing a coherent train of thought together. Also, it seems that as his reign over the facility continued, he slowly became more and more capable. From having trouble with his horribly built walking boxes to designing some formidable death-traps (the mashers), it's possible he was getting smarter just from having to do the job.
 * Him staying in the mainframe is the most terrible decision by a long shot as it'll cause the facility to blow up and the most reasonable thing to do would be to hand himself over to GLaDOS so that she may take control and fix things. Given the horrible long term effects of Wheatley staying in control, chances are his programming allows him to be as competent as he needs to be in order to continue keeping Chell and GLaDOS away. After all, GLaDOS does clearly make the emphasis that Wheatley isn't just designed to be an idiot, he's designed to be an idiot by the world's smartest men, making him rather special in a Crouching Moron, Hidden Badass way.
 * Also, it might have been that his role was, whenever GLaDOS tried to come up with a plan, try and derail it in such a way that neither she nor Wheatley would notice until it was too late. Evidence in favor: "Talking outside her range" i.e. with a bad American accent, failing to notice or remove the vacuum pipes containing Gel of various types on at least three separate occasions in the boss fight alone, forgetting about replacing the "crap turrets" after coming into power, GLaDOS mentioning that he was designed to come up with "stupid, unworkable plans", the list goes on.
 * It's important to note that GLaDOS describes Wheatley's purpose not to be an idiot but to make bad decisions (so that, by proxy, GLaDOS would also make bad decisions and be flawed). This doesn't mean he's an idiot (though GLaDOS calls him such so that he gets angry) just that he's the type that does not always consider his options, does not consider the big picture, and does not always have the best self control (procrastinate on homework or actually do it). This also means a lot of his behavior is the result of simply a string of intentionally poor choices; of superstition, of deciding to trust the wrong people, and so forth. As a result, this doesn't mean he isn't smart or clever... just that he ultimately causes more harm than good. He ignores the reactor AI warnings for instance and decides that six minutes is enough to kill Chell and fix everything. Beyond that, he also comes across as the devil's advocate in the mainframe - the personality core that would question and present odd solutions not just to create a flawed GLaDOS but to allow her to occasionally think outside the box.
 * Wheatley was created by the most brilliant minds in order to make the worst decisions possible. Which means that his purpose is basically to be extremely brilliant in the art of failing. Since not letting GLaDOS take over counts as a really bad decision, he was extremely competent in stopping the best thing that could've been done in that situation. So basically, he wins at failing.
 * So in essence, he's the computerized version of Epic Fail Guy!
 * Wheatley brings to mind, possibly due to the British accent, a description of how the Tardis works in the current series. Paraphrased: "The Tardis lands and in the briefest of moments scans for thousands of miles around that location. Calculations the best disguise for that location. Then it becomes a police box." We have here an AI designed to the be the dumbest thing ever. No, it can't simply be dumb. Wheatley must have the capability by design to calculate every every possible contingency, idea, plan based off of the information he has access to. Then he is programed to pick the second worst plan. The worst by default would be do nothing due to his primary goal is to create and influence GLaDOS with bad plans. Aperture devices tend to be a little wonky in the first place and Wheatley is later shown damaged and sparking. The part of him designed to pick the bad ideas is damaged/failing, but not completely failed, by Portal 2.
 * Or, knowing GLaDOS, the stupid thing would be going against her.
 * Or going against Chell.
 * As pointed out elsewhere on the wiki, Wheatley was made by Aperture Science, none of whose creations ever worked for the purpose they were built for. In this case, they failed to purposefully make a moron core -- hence the flashes of smartness behind his Cloudcuckoolander behavior.
 * Because he was programmed to make the worst possible decision. This means he had to be capable of computing as many different scenarios as GLaDOS, ranking them in order of best decision to worst, and then pick the worst, without realising it. In other words, the scientists would have to program him to make the best possible decisions, and then change a > sign somewhere in the code to a < sign.

Wheatley in charge of hibernation

 * Why was Wheatley, a purposefully stupid individual who inevitably bungles almost everything he does, put in charge of watching over hibernating test subjects in the first place? Is that GLaDOS' idea of a joke?
 * Who says he was actually put in charge? Not only do you not see him on your first scheduled wakeup, but in hindsight it's pretty obvious that Wheatley hauled you out so that you could make a run on GLaDOS for him.
 * GLaDOS might have assigned him a menial task (the preservation of human life doesn't seem that important to her) so that he would be far away and wouldn't infect her with his stupidity as he was originally designed to do.
 * Improbable, since GLaDOS
 * Wheatley probably didn't work VERY well on GLaDOS. Whilst he did slow her down from attempting to  he made her a bit... TOO stupid. The Morality Core did his job just fine. So, who's gonna look over all of the test subjects? Aperture Science already own shitloads in debt. This Core doesn't have a job. Let's just get him in there! It's economically friendly, a fast solution, and it'll give the world of science new insight into what the world's greatest moron would do when supposed to be looking after hibernating test subjects! A win for everyone! Except the ones who are dead.
 * I don't think it's a question of "too" stupid. I think it's a question of GLaDOS figuring out which voice was Wheatley's and quickly learning to ignore it.
 * Wheatley mentions in his banter that the foreman gave him to job of "tending to smelly humans" after filling the position that Wheatley wanted with an exact duplicate of himself. This means that a robot made the decision, and we all know how little foresight robots can have in this series.

Deleting Caroline and "Want You Gone"

 * A troper already mentioned the line, but why did . Did somebody forget to tell Jonathan Coulton about a change to the ending? Was she lying, and then decided to suddenly stop lying?
 * GLaDOS is notorious for bending the truth, so it's entirely possible she was pulling one over on you.
 * Two words: Recycle Bin
 * Still Alive asserted things that turned out to be false, like how GLaDOS was still alive after you destroyed her, was happy for you, and wasn't angry you burned her, even though she wasn't any of those things. Why should Want You Gone be any different? They were liberties JoCo took to write a good song.
 * Also, Portal was a breakout sensation, so naturally when a sequel was penned the direction for a more broad audience and for continuation purposes would be much different than the initial idea for Portal. So things had to change from Still Alive's lyrics for a sequel to even work. For Portal 2, not so much - they probably planned around a continued story much more. But she certainly doesn't seem like Caroline in co-op, or its ending...
 * GLaDOS is a lying liar who lies. There's a lot of speculation that she was lying about deleting Caroline. For example, she says that  because it's easier than  . But she could have just , or she could have   when you lost consciousness afterward. Even if we assume she had to delete Caroline in order to do this, she could have just done it earlier, instead of waiting. I think she's just trying to cover up the fact that she actually has something of a conscience now.

Likelihood of final shot location

 * Probability of hitting a spot on the moon that has an abandoned Lunar lander. I've done some research and there's quite a handful of them stranded on the surface, but come on.
 * It's just one of those little visual gags more or less. Whenever someone in a cartoon or comedy movie arrives in some certain area, usually there's some artifact or whatever related to that area that just happens to be right where they materialize or arrive at.
 * Rule of Funny
 * It's like how almost every TV show that has an episode set in London will inevitably have a shot of the Houses of Parliament in there somewhere; it's just a visual signifier to let you know that "hey, this is the Moon!" Unlikely, maybe, but it's hardly the most unlikely thing ever about the Portal series.

Emancipating Potat OS

 * Why didn't the Empancipation Grills destroy GLaDOS' potato? Even if her personality core isn't considered "unauthorized material", what about the potato itself?
 * Perhaps the fact that it was literally wedged onto the portal gun made destroying it too risky, or even undetectable.
 * If I remember right, it's stated that the Emancipation Grills are intended to destroy "Unauthorized Aperture Science Equipment". GLaDOS is authorized, and the potato is a potato and not Aperture Science Equipment so it's just overlooked. Or the potato is authorized since it provides enough electricity for Aperture Science Equipment to function in apocalyptic settings.
 * It was authorized for all the science projects the kids were doing. Note that the entire facility is overrun with potato plants.
 * Maybe the Grill only fizzles unauthorized things that it can positively identify as contraband. Potatoes would not not be on the "fizzle list", just because they would not be expected.
 * Along with all these, I'll add that potatoes are organic material. The Grill isn't supposed to affect organic material (occasional ear-tube-emancipation notwithstanding), otherwise they'd have a lot of fizzled test subjects.
 * The grills are probably designed to not destroy food objects, otherwise the test subjects would starve to death mid test after having the contents of their stomach emancipated or have to take a lunch break after each test

The setting of the end

 * The end
 * Heard it was more like 300 years. Beside, you're forgetting Gordon "Anticitizen One" Freeman. The Combine don't stand a chance. Now if you want to get meta...have you played the unofficial mod "Portal: the flash map pack" for the first game? It does end with Chell about to be ripped to shred by a Combine gunship, quite a Downer Ending. Don't you believe Chell has earned her happy ending?
 * Portal takes places 30 years after Half-Life. Portal 2 takes place three hundred years after portal. That's plenty of time for everything with those aliens and stuff getting cleared up and the world starting to clean itself up.
 * The ARG (Alternate Reality Game) has the hypernation timer set to "9999" days, which equals just about 27 years. The Half-Life Wiki sets portal 1 at around the same time as Half-Life 2. That should put Portal 2 no more than 2030, a bit shorter than 30 years. It would make sense to WGM this to capping off the combine invasion of earth within too many years after Half-Life 2. IF Valve actually finish the series
 * (I'm just gonna go ahead and point out that the hibernation timer actually says "9999*fizzle*99") meaning either the timer is broken (most likely) or that it has been almost 3000 years.
 * (Incoming wall of text, very sorry) I don't think so. Here what I think: We know that GLaDOS was activated in 200- (source: Combine Overwiki and Lab Rat comic if I don't make a mistake). The activation and subsequent killing of the scientists is mostly agreed to happen while the Black Mesa keep everyone else busy, preventing any rescue attempt. It is also generally aggreed that Half-Life 1 happened in the early 2000's. A few month following that (not much more, Rattman was, uh, Still Alive in the center) the event of the Seven hour war have probably already happened. GLaDOS did say she has no understanding about what was happening on the surface, but it's implied and generally agreed that she was maintening some sort of defenses against the Combine. Now then, at time of those events, Alyx was a toddler. Since she is not so much of a baby in Half-Life 2, and since the youngest citizens appear to be in their mid-late twenties (combine's anti-sex fields and whatnot), I think Half-Life 2 takes place somewhere between 2020 and 2030. Considering the timer from the ARG, it could mean that Portal 2 really happened at the same time as Half-Life 2, more or less. Sweet, except that the timer is implied to be a bit of a joke, and the voice you hear when Chell awaken for the second say a bunch of nines before being cut short. Point being, maybe the timer actually hit its cap and the actual duration of Chell hypersleep is way more than 27 years. On the other hand, I think 27 years is enough to account for the centre being heavily damaged but not completely destroyed. Extremely few things done with today tech would survive 27 years of Gaia vengeance in perfect state. Even underground, you'd have to account for the hyper devastating power of moist. Trust me, it's something that can destroy anything in its path. I mean, even Rattman's scribling being so bright in color after 27 years is seriously stretching it, let alone 300 years.
 * This is the science facility which, the series has shown to play rule of cool/funny whenever it can and given that the series was playing up how much Aperture had changed after the stasis then it's would be anti-climatic to have the stasis not be as horrifyingly long as implied in the name of realism.
 * Display caps. Many programs expect only 4 or so digits, and any more are cut off (esp. if there're physical space restrictions, but it also happens in other places). Not to mention integer overflow. Maybe it says 9999 days, after rolling over from 32768 to -32767 a couple times.
 * This troper has a different idea. Most programmers like to store data in double-precision so they don't have to worry about overflow (it would take far far longer than the age of the universe for such a day-counter to overflow), so its likely not that. I think the problem is when its converting the number to speech. The announcement seems to be like those you might hear when calling up some automated call center. Spoken numbers are highly modular so saying something like "3,945" comes out as three...thousand...nine...hundred...and...forty...five, with each word as a separate sound bite that can be ordered in any way by the computer. The problem is that the computer needs a word that hasn't been pre-recorded. the numbers one through nine would be out, and we hear the announcement say "fifty" first, so all two digit numbers are likely covered. I would inclined to think three digit numbers are also covered, since one hundred is only twice as long as fifty. The next two would be "thousand" and "million". "Million" seems way too long as nine million is almost 25,000 years. Nine thousand seems just about right. So what the announcement is trying to do is say nine...thousand... but "thousand" isn't in its vocabulary, so it crashes and repeats the "nine" part still in its memory a few times before finally quitting. So Chell has been asleep somewhere between 9,000 and 10,000 days, which is 25 to 27 years.
 * Although we are talking about the utter insanity that is Aperture science. For all we know, it starts counting in another unit when talking about lengths of more than one year. It could have been talking in scores, pie-baking times or radioactive decay. This is one of the main problem with creating a viable portal theory; everyone is too insane to give any credible evidence. Alternatively (And way too sane for aperture), hundred-thousand is counted as a single word and it doesn't know that.
 * Note that Earth, as viewed from the Moon, seems to have its oceans back (in Half-Life 2 the Combine were clearly draining Earth's oceans with water levels already dozens of meters below normal), which suggests that the Combine takeover plans went pear shaped.
 * The draining of the oceans by Half-Life 2 time has only pushed the water out a few hundred feet, way too small an amount to see from space. Plus, the parts of the Earth we see are being viewed from the Moon, meaning they're at high tide.
 * A few hundred feet "out" yes, but a few hundred feet of lower sea level would easily be visible from the moon (disappearence of most of the Hudson Bay, Baltic Sea and Northsea, Indonesia blocks with Australia and SE Asia). I always understood the latter was meant.
 * To answer the OP, just because we don't saw a Combine armada during the whooping ten seconds part of the ending where Chell is actually outside, doesn't mean they aren't around. GLaDOS was obviously making a absurdly good job keeping them at bay, considering how much they lust on human teleportation technology. Also, what's to say there is a combine presence in North America? We only know for sure they were present at least at some point in Eastern Europe. Maybe N America was lost and abandonned after the Seven hour war due to the portal storms and Xen invading fauna. Heck, considering how little interest the combines had the wilderness in Half-Life 2, maybe there is a higher "chance" for Chell to stumble on a headcrab than a combine gunship.
 * God, how many times does this have to be said? Word of God states that the Half Life universe and the Portal universe are being kept separate! Do all you Wheatley-level morons understand that word? On the off chance that you don't, it means: kept apart; not together! When, there was no Combine invasion! So anything could be happening outside. And judging by the technology level, the games are set Twenty Minutes Into the Future. So, who knows?
 * Really? I remember Word of God stating that Chell "has importance with characters we already know...
 * First, I think you should calm down. Second, Valve is notorious for changing their minds or leaving ambiguous answers. Keeping them separate could refer to the games being made different times(so if another Portal game comes then it will be after Half Life has finished or something). Also, GLaDOS says herself that she's the only thing standing between us and "them" and Black Mesa is mentioned a few times.
 * I know we don't do citations, but in this case I really have to say [Citation Needed] for this. Both Portal and Portal 2 have several links to Half Life (Black Mesa is mentioned a lot), and Episode 2 has links to Portal (The Aperture Science logo on the Borealis). I'd really like some context of what was said, who said it, and where it was said.
 * Fridge Brilliance - remember this video in the elevators during the hard light bridge areas? If you look closely you can see the shack that you emerge from at the end of the game. The fields presumably provide power etc. for its systems, including the bridges, and so are maintained by the facility, therefore what you see at the end has little to no bearing on what the rest of the world looks like now.

Getting moon rocks

 * So if moon rocks were so expensive they could hardly afford them, why didn't cave just send someone up to the moon in a pressurized suit using an airlock and a portal gun so he could go grab some?
 * Cave is the type of person to build a giant turret just to make an animation of one. It's too sensible for Aperture Science.
 * Or maybe they did? I'm not sure in what proportion the moon dust would have to mix into the gel, but they have A LOT of portal gel to spare throughout the game.
 * One could assume they did try to collect some in the 60s, but because of the "Senate hearings on missing astronauts" had to abandon it or cover it up for the time being.
 * He was fucking broke. I think he said that some scientists told him he couldn't afford seven dollars worth of Lunar Rocks, let alone the amounts needed to make all that portal gel. He probably wasted the majority of the company's funds on that.
 * They only found out moon rocks were good for holding portals until after they bought them and ground them up. Granted, they could have found out sooner by just shooting the moon, but that would require rational thought and it wouldn't be Aperture Science unless they were doing something ass-backwards by warping the fabric of space-time with dangerous and experimental technology while being shot at and poisoned.

The logo on the Borealis

 * This one is about a small Plot Hole that I found. In Episode 2, the Borealis has the modern Aperture Science logo on it. In Portal 2, you find the Borealis' former Drydock. Sounds fine, right? Notice the logo hanging in the lobby and in the loading screen. Why would they be using a logo from the future on their gigantic ship? How would they know what it'd look like?
 * The ship may be newer than the drydock. It's not inconceivable that they didn't update the logo.
 * Alternatively, they updated the logo on the ship later on at some other harbor.
 * Outside of story reasons, I figured they threw that in there as a way to say "Episode 3 is coming, just be patient" by referencing where you were heading at the end of Episode 2.
 * More to the point, what is a ship dock doing several kilometres underground?
 * If you are going to run some crazy teleportation experiment that you don't want a certain rival company to see... Well, it's probably the best place to put it.
 * Based on the documents from the screenshots in Half-Life 2, we know that the Borealis was in service for some time before she disappeared. Since ice breaking ships need to be refurbished every 20-30 years or so (and the AI version of GLaDOS was being developed as a new fuel system de-icer), it's probably safe to assume that the engineers were trying to teleport the ship back to Aperture's underground drydock for upgrades when she vanished.

Submerging the gun in gel

 * One of the warnings you get when you pick up the portal gun is to never submerge the device in liquid, even partially. In Portal 2, you can literally stand in a never ending cascade of the various gels without issue. And of course, there are two parts of the game where the gun can safely touch water (including when the sprinklers come on after the final boss fight).
 * Maybe the gels were designed with the ASHPD in mind? Or they're simply not conductive? As for the sprinklers, that hardly counts as "submerging".
 * I always got the impression the gels were oil based anyway, sort of like paint.
 * Doing something you're not supposed to do isn't always going to result in catastrophic consequences 100% of the time, you know.
 * I always figured it was supposed to be a joke on how Aperture Science is more worried about the ASHPD falling into deadly water than the tester drowning. The Trailers basically confirm this.
 * The gels being potentially paint-based still doesn't explain the pouring water in some of Cave's test chambers that you can clearly submerge the portal gun in. Another lie from GLaDOS, perhaps?
 * Or it's a new, waterproof model of the Portal gun in the second game.

Invention of the gels

 * You find the Repulsion Gel and Propulsion Gel inside the 50s-60s era Aperture Innovations testing spheres. Yet the Combine Overwiki places the creation of Repulsion Gel at 1998. What the hell?
 * Aperture Science has a history of not publishing it's findings. Chances are, Black Mesa (or another group) independently came up with repulsion gel in '98.
 * The Combine Overwiki is a wiki, you know. I could go and change the date for you if it'd make you feel better.
 * OP here, bad research on my part. 1998 is the year that the Gels were released as products to the public, not the year they were invented. My bad.
 * The wiki is currently having some issues reconciling the timeline (as the stuff we find out in Portal 2 doesn't mesh with the official timeline we previously had, such as the notion that the Portal Gun was invented during Cave Johnson's time and not something he decreed they work on on his death bed decades later)

Gravity on the moon

 * The moon does have gravity, even though it's less than Earth's. When Neil Armstrong walked on the moon, he didn't go flying off into space, he just bounced with each step. Wheatley should be sitting on the moon's surface, not floating out in space.
 * The pressure differential meant that air (and everything else) was rushing out the blue portal very quickly. If a homerun can achieve lunar escape velocity, Wheatley definitely did.
 * The lunar escape velocity is 2.4km/s, which is unlikely to be achievable just from the speed of the air coming through the portal, especially since it is not confined to anything like a gun barrel. You might save a little speed by saying that Wheatley went into a lunar orbit instead of strictly "escaping", but not that much. Call it Rule of Funny.
 * Maybe Wheatley is just in a high sub-orbital trajectory that will eventually impact the lunar surface.
 * He might've also gained a bit of speed when GLaDOS knocked him off the mainframe with that mechanical arm.
 * The air pressure on Earth is about 100kPa. That means that the force exerted over a portal (about 1 square meter) is 100kN. If Wheatley is 10kg then his acceleration is 10kms^-2. Apply that force for 1s and he's already traveling at 4 times faster than escape velocity.
 * That's pressure over the entire portal area. Wheatley is much smaller and would only experience a fraction of that pressure. And 1 second is very genereous; he was likely exposed to any significant pressure for a fraction of that time (from the moment GLaDOS knocked him off until the the effects of the air became negligible).

What is GLaDOS?

 * What exactly IS GLaDOS at this point? A Genetic Lifeform and Disk Operating System? Okay. The new boss of Aperture Science due to the last request of Cave Johnson? The acronym's vague enough to make those two compatible. But how can she also be a fuel-system de-icer gone horribly wrong? It seems contradictory.
 * Genetic Lifeform and Disk Operating System and de-icer were supposed to be - well, not contradictory, but they made unnecessary work out of de-icing. In terms of Caroline, it's possible they killed two birds with one stone: "Well, we need a system to support Caroline's brain and we have this big life system here. Let's put it in."
 * From how I understood it, based on the slideshow easter egg from Portal 1: In the 80's Black Mesa was, as always, getting tons more government funding than Aperture. Aperture was desparately trying to impress the government by how better they were than Black Mesa, and somehow got wind of the fact that they were building a fuel line de-icing system. They wanted to one-up Black Mesa, so they integrated their fuel line de-icing system with the newly created GLaDOS/Computer Caroline, while somehow keeping the cost below that of Black Mesa's system. GLaDOS is still officially a fuel line de-icer, but is really a DOS hooked up to the mind of Caroline.
 * GLaDOS and Caroline are almost nothing alike, personality-wise - GLaDOS is basically a high-tech passive-aggressive AI with the Virtual Ghost of Caroline in her brain. She even states so herself at the end: "Caroline lives in my brain".

Poisonous Conversion Gel

 * Cave Johnson says that ground up moon rocks are "pure poison." Chell comes into contact with, and can even bathe herself in, Conversion Gel multiple times throughout the game, and yet she's completely fine? How does this work?
 * It is possible that Cave Johnson was simply allergic to moon rocks. Goodness knows that his grasp of science isn't exactly error-free...
 * Or that Chell really does only have her "short sad life back". Then again Aperture have had 50 years of research and you bet finding a cure was one of Cave's top priories, maybe they made it safe by the time we find it.
 * Maybe the poisoning happens when moon dust is inhaled. With the gel, there's no dust to poison you.
 * Johnson did mention something about suspecting that jumping through portals laid on conversion gel might reverse the effect. Unlikely as it may be, perhaps he was right.
 * Poison =/= Acid. The first two gels were attempts at creating a dietary product. Chances are the moon-gel was a third attempt that Cave tried on himself.
 * Also notice how Chell can be covered in the blue gel and not have her skeleton disintegrated, despite Cave's warnings.
 * This is the same man who thought going through a portal would somehow suck the poison out. I think it's safe to say he was just as unreliable a narrator as anyone else and possibly so nutty by that point that he wouldn't know the moon from a vat of mercury.
 * He didn't say the Repulsion Gel would disintegrate your skeleton, it said that it doesn't like the skeleton. This could mean any number of things.
 * Also, maybe it would "suck the poison out" if these are the same portals that could strip you of your skin. The poison would drain out with all your bodily fluids.
 * Maybe they did work out the ingredient that doesn't like the human skeleton and fixed it? They didn't update the recording because that test area was condemned, but the tubes all run from the same reservoir which got updated gel.
 * The poison thing has a basis in real life: Inhaling lunar dust has effects similar to inhaling asbestos. However, it's only hazardous as a dust, not as a liquid.
 * Or maybe the effects are not immediate, just like many real-life poisons.
 * Cave says that "ground up moon rocks" are poisonous. He doesn't say "conversion gel" is poisonous. Maybe they put something into the gel that negates the poisonous effects?

GLaDOS's new body in her old location

 * If the chamber where GLaDOS re-activates is the same chamber that you killed her in, why does she have her new body instead of the old one?
 * Because last time the entire thing was blown outside the complex. Presumably the bots put her back together but couldn't boot her up.
 * It's just a style retcon, like Chell having boots instead of implants.
 * The boots aren't a retcon, actually. The comic shows that her knee implants were destroyed after she killed GLaDOS. The boots are their replacement.
 * Maybe Jerry and the other nanobots in the work crew tries to help fix her up?

Chell's age

 * If Chell was a kid at the time of the Bring-Your-Daughter-To-Work Day Massacre on May 16th, then she was in the relaxation pod for about twenty years before being woken up at the start of Portal 1. That means that she was still growing up into womanhood despite being in stasis. If that is the case, then why does she not age over the span of time she spent trapped in the Relaxation Chamber in Portal 2?
 * There is nothing in the comic that imply that Chell could be one of the kids from the bring-your-daugther-to-work Day, so maybe the "Chell" name on the potato experiment is just a red herring.
 * The Lab Rat comic specifically states that she'll be in cryo-sleep. Try aging when you're a Human Popsicle.
 * Or maybe the Bring Your Daughter to Work Day happened quite a long ago, and that particular level was abandoned completely because of what happened there.
 * It's also very possible that she was sleeping for hundreds of years before the first but only 30 years preceding the second. She didn't stop aging, just aged veerrrryy slowy. So let's say 100 years in cryo-sleep=10 years of aging. She was about 10 on BY Dt W Day, then aged 10-15 years over the course of 100-150 years of cryo-sleep. She then aged only 3 years before Portal 2.
 * Well, growing into maturity and aging into oldness are not the same processes. It's possible that Aperture's method of stasis stop the latter but not the former.
 * Alternatively, the cryogenic technology used between Portal and Portal 2 is an improved version of the technology used between BYDTWD and Portal.
 * Alternatively 2, Relaxation Vaults and Relaxation Centres are different. Maybe one is short term sleep (keeping the subject alive and asleep but not in statis) and the other is cryogenic suspension?
 * Alternatively 3, some unstated amount of non-stasis time passed between BYDTWD and the events of Portal 1. Either GLaDOS had her out of stasis for other forms of testing beforehand, or she was not captured right away during BYDTWD.
 * She was clearly interviewed in the Rattman comic as an adult by Apeture Science staff members before GLaDOS wiped everyone out with neurotoxin. Either (a) she grew up to adulthood before everything went pear-shaped, or (b) someone continued to do interviews after the facility was locked down and the Rattman is somehow aware of the contents of these interviews despite being on the run from GLaDOS at the time.
 * It's also possible that, despite the timeline we were initially given (which runs into several problems when you compare it with the information given in Portal 2 and Lab Rat), the first Bring Your Daughter to Work day was not the one where GLaDOS killed everyone. Perhaps they'd been having them for years, and the one where Chell made the potato battery happened years before the one where GLaDOS took over. She could have gone to the latter as an adult (no one said the daughters had to be children). No aging-in-stasis required.
 * The Bring Your Daughter to Work Day banner over the potatoes in Portal 2 is printed on 80s era paper, the kind with perforated edges and holes, which could point towards it being a recurring event.
 * This is getting slightly WMG-ish, but it's possible that she's actually been doing tests for years before Portal. No reason why GLaDOS couldn't reuse the same test subject over and over again, especially one so skilled at solving puzzles. In Portal, after testing the ASHPD, she finally decided to kill her (for a number of possible reasons; maybe protocol required to kill test subjects after using the ASHPD in order to keep company secrets, or she was getting worried about her rebelling). Hence why she's aged; she's been in and out of stasis for the past couple of decades.
 * Another possibility is that GLaDOS somehow artificially aged the younger test subjects. Aperture could turn blood into gasoline and peanut water, after all, so it isn't too far-fetched.

Position of the final room

 * Here's something that's bugged me for a bit: In the final battle, you shoot through the roof of the facility at the night sky, right? Then in that EXACT SAME ROOM just a bit later, it's required to ride in an elevator up an unusually long shaft in order to reach the surface because the whole facility is underground. Non-Euclidean ceilings, perhaps? Either way, it bugs me.
 * The entire facility is reconfigurable. One moment, Wheatley has it at the surface. GLaDOS put it back when she had control again.

No periods?

 * Does Chell ever get her period? Did she get it while in stasis? How would she handle it while testing? Would she be provided with the proper... sanitation?
 * Maybe she has an Aperture Science Blood Absorption Cup. But this is probably just like many other things An Acceptable Break From Reality.
 * This is just Nobody Poops. Nuthin' to see here.
 * *Facepalm* In both games, Chell was out of stasis for a few hours, tops. Even if she did have to worry about that at the moment, which would be far-fetched to begin with, she was preoccupied with other matters -- such as, you know, getting out of this deathtrap of a facility, fast. Besides, this is Aperture Science we're talking about. Chell has long fall boots -- it's possible that test subjects are also equipped with special clothing to avoid distractions like periods and toilet breaks. And stasis is stasis. Bodily functions are suspended.

Moving portals

 * Just a small detail I noticed: Portals are supposed to disappear if the surface they are on moves, right? Then how was that whole 'chop off the tubes leading to the neurotoxin generator with a laser through a portal on a moving platform' thing possible?
 * Easy, the moving platforms were designed with the idea of portals being placed on them, just like mostly everything else.
 * The only times we see them disappear on moving platforms are when they're moving along an axis that is not parallel to the portal. If you noticed, the platforms in the neurotoxin room were moving on the same axis as the portals. That's probably why they stayed.
 * Not true. After the part where he kills you, Wheatley moves a large test chamber to cut off your catwalk. The base is portal accepting surface that moves on same axis relative to the portal as at the neurotoxin generators and yet will not accept portals until it stops.
 * Not really. The portal is oriented vertically but the surface is moving horizontally. In the neurotoxin examples, the surface is moving in the same direction as the portal orientation.
 * The panels are reconfigurable, right? Probably, the facility has a mechanism to fizzle portals on moving objects to avoid people throwing one portal into another. When the panels are being assembled, the mechanism isn't necessary, thus, it doesn't happen.
 * My theory was that you can't place portals on surfaces with a surface with any velocity changes (speeding up or slowing down), unstable movement, or rotation on any axis. A surface in motion at a constant speed (like the Moon, or a sliding wall) would accept a portal.
 * Or the Earth, for that matter. The Earth itself is an entire moving surface, so I think it can for the most part be Hand Waved.

No one got the gun before Chell?

 * Wheatley says near the end of the game that Chell was the fifth person he woke up to get the portal gun and the rest died trying to get it. Looking back at the beginning of the game, getting the portal gun was really really easy even for those not familiar with portals (and there wasn't anything really dangerous involved) so why did all those others fail to get the gun?
 * Well, Wheatley probably screwed up, and they were probably suffering from extreme brain damage.
 * This is just a guess, but it would be in-character. The first try, Wheatly forgot about g-forces and moved the chamber too fast, killing the inhabitant. The second time, he tried to "manually override" a spiked plate. The third time he finally managed to break through the walls, only for it to be the wrong spot, resulting in the test subject falling in an incinerator. The fourth time, he simply put the subject in the nearest place where it was safe to stand, resulting in death by dehydration before ever getting close to the portal gun.
 * Or maybe they didn't have long fall boots.
 * The only reason it was so easy was because he dropped you off at the right spot -- but he had to break through a wall to get there. This means that the others had to have been dropped off somewhere else in the facility -- likely somewhere more dangerous.
 * Also, there is probably more than one portal gun in the facility. Wheatley probably took the other four people to other locations that were more dangerous.
 * It may just be me personally, but I believe that Wheatley was lying about awakening other test subjects before Chell. There are several reasons. Four-part plan, maybe?
 * One: The things Wheatley says at the beginning of the game. Not only does he tell Chell that most of the people he was supposed to be taking care of in the chambers have died of neglect, if she hangs around long enough before opening the door to him at the very start of Chapter One he tells her that she's actually the only test subject left. This can be tracked down to Rattmann in the Lab Rat comic, rebooting her chamber whilst the rest of the grid remained offline which systematically killed the remaining subjects. Of course, we know that there are actually a few more subjects alive somewhere in Aperture due to the ending of the Co-Op Gameplay, but it's entirely possible that Wheatley was simply given control over a certain grid of subjects and either had no knowledge of the others sleeping elsewhere or had no hands to impersonate a human and access them. As far as he knows, Chell really is the last test subject alive, miraculously.
 * Two: Wheatley's state of corruption when he tells Chell she wasn't the first subject. Somewhere past the halfway point in the game, GLaDOS says that being plugged into the mainframe with other cores is maddening, like hearing several voices constantly chattering in your head at once. Wheatley's already pretty far gone by the time Chell arrives for the final confrontation anyway, but it's when he is slowly fused with the corrupt cores that he really loses it and begins to spout all other kinds of lies and paranoia as part of his villainous breakdown. By that point, he's declaring that Chell and GLaDOS had a plan against him from that start, that the reactor core doesn't actually exist and neither do the papier-mache-and-SFX fires apparently raging throughout the facility. He accuses Chell of deliberately not catching him at the start of the game, of tricking him into assuming power and maliciously fooling him into showing her where to find a portal gun. He also declares that he loathes Chell quite explicitly if you give him the chance -- and that she's fat, obviously. Really, telling her that she was an easily replaceable pawn in his master plan to take over from GLaDOS is essentially just another emotional blow he tries to hit her with to stop her jumping around and dodging his bombs.
 * Three: The reason that particular piece of audio exists in the game at all. According to the developer commentary, there was actually supposed to be some part of the gameplay at the beginning that hinted there were others before Chell, awakened and used by Wheatley before subsequently getting killed horrifically. As it is, it was dummied out. The audio of Wheatley mentioning this still remains in the boss battle but now actually there's nothing to back it up, therefore no particular reason not to believe that Wheatley is simply raving like the insane, moronic little manchildbot he is by that point.
 * Four: The unspecified amount of time passed since Chell was put to sleep. Some say thirty years, some say three hundred -- whatever your own figures are, it's an awfully long time to be trapped and unconscious in a preservation chamber that's offline. Chell was personally saved by Rattmann, as we know; who saved the others? Wheatley claims he didn't know anything about the chambers being offline at all, which can be chalked down to his simple-mindedness easily enough. It stands to reason that he probably wouldn't even check until he thought he might be in danger from the deterioration of the facility and therefore needed someone to help him escape. In the meantime, uncounted numbers of people were lying in empty rooms with no food, water or any way to wake up. Just a quick note: the human body rarely manages to sustain itself beyond three days once it is deprived of water, let alone thirty years.
 * Part Five:

Reason behind the Anger Sphere

 * The personality cores were made to keep GLaDOS under control and stop her from killing everyone, right? Then why did they give her an anger sphere?
 * Perhaps they thought she'd become so cross, she'd make a mistake.
 * These are the people who gave the turrets both an Empathy chip and an Empathy suppressant, and simulated pain response. They just put these things in.
 * Yeah, this troper feels likewise. I mean, after the most logical installments fail to stop her (namely the Empathy chip and Morality core) where do you go from there? I get the impression that they quickly began to ran out of options and the stranger additions to her circuitry were probably added on a hope and a prayer that they'd succeed.
 * That's actually her Emotional Core, not her Anger Core. She's just really pissed off.
 * It's described the first game's credits as "The Anger Sphere" though,
 * Also, remember how she experiences the other cores - constantly babbling voices in her head. At some point, they may have simply decided that overwhelming her with voices was a 'better' solution than a single/handful of rational voices.
 * Imagine the scientists swapping cores in and out of GLaDOS to see what would happen. They'd stop when either they get what they want... or one of the cores causes GLaDOS to do something evil, preventing the scientists from continuing their work!

Wheatley's stupidity in the second half

 * Maybe it's just this troper, but I couldn't stand the way they played up Wheatley's stupidity in the second half of the game. Up until he took over for GLaDOS he seemed to have things together. Maybe he was a bit goofy, sure, maybe he did accidentally awaken a murderous supercomputer. Other than that, his logic and reasoning in the first half of the game is pretty top-notch. Then when he's plugged into GLaDOS he suddenly becomes as dense as a bag of rocks. Felt more like Character Derailment than any actual progression of the character, to me.
 * What about "I'm talking in an accent that's beyond her range of hearing?"
 * Or trying to hack the Neurotoxin computer? There's more idiocy in that one set of lines then the entire rest of the game combined.
 * Or the classic hacking attempt: "A... A... A... A... Umm... A. *BUZZER NOISE* Nope. Okay. A... A... A... A... A... C. *BUZZER NOISE* No. Wait, did I do B? Do you have a pen? Start writing these down."
 * It's a reasonable approach, he just took way too long.
 * "I'm pretty sure this is a docking station" (sign says "Docking station 500m below"). Or "I'll try manual override on this wall!" (...whamwhamWHAM!!!). Or trying to "hack" a door without noticing that it's already open...
 * Arguably, Wheatley unthawing Chell was a stupid idea - doing so allowed the events of the game to happen, and the biggest result, aside from Chell's freedom, is [=GLaDOS 's=] reactivation. Which... is pretty high on the list of "stupid things to do".
 * And let's not forget the array of abilities he's been given, but he doesn't dare use them as he was told he would die if he ever tried using them. And he believed it.
 * If someone told you that you would die if you did something, would you test it unless you absolutely had to?
 * Wheatley seems more stupid in the second part because he can do more. When he was still just a sphere, he could barely do anything. And then there's his beginning to hack the neurotoxin generator: "That's a computer. That's a monitor, that could come in handy..."
 * He's a computer himself; he probably doesn't need a monitor to hack.

Chell's last name

 * Wouldn't the people with the same last name as Chell be her adoptive parents? So, not the ones who "abandoned" her, but the ones who took her in?
 * Well if she was "left on Aperture's doorstep" she wouldnt have a last name for adopted parents.. unless it's "Laboratories" or "Science"..
 * She wasn't left on Aperture's doorstep, she was left on "a doorstep". GLaDOS doesn't mention where.
 * Remember, that was before GLaDOS told Chell that she was adopted; GLaDOS was lying and Chell didn't have enough information to figure that out. Or maybe she did, but didn't say anything and just went along with the test. Relatedly, how exactly does GLaDOS know that?
 * The Lab Rat comic shows that Chell's last name was redacted from the official records, so it's possible that GLaDOS doesn't even know what it is. That said, Chell did show up during Take Your Daughter to Work Day, so GLaDOS ought to know who her parents are.
 * There's also a theory that GLaDOS thought Chell's actual last name was [REDACTED], and that there were two other people whose names were tagged this way, so she thought they shared the same last name.
 * And then there's the chance that it's all just made up. Maybe she wasn't adopted at all, maybe GLaDOS didn't find two people with Chell's last name.

Defective turrets

 * How did the defective turrets all come out the same way? If they're based off the real turrets, how'd they lose the cute little voice and personality?
 * That facility is pretty damn old. Sure, you have test chambers that can be rebuilt and machines that build turrets, but I doubt that you have specific factories that manufacture the machines for building turrets and as future-proof as this facility is, something will break beyond repair at some point. Chances are that at least a third of the manufacturing stations is just screwed beyond repair, making the same faulty model.
 * Out of universe, it would have probably taken too much time to make thousands of different kinds of defects (missing leg, missing guns, faulty guns, faulty eye...) and it would have been rather hard to differentiate them from good turrets if only little things were different. Thus they made the defective turrets very obvious and all the same.
 * They're not all the same. Some have most of their casing still on, some are skeletons, some are still in their boxes and some are assembled partially sideways.
 * But you're missing the point — they're all missing the cute voice and they all are more self-aware than the normal turrets. How'd they end up like that?
 * The regular turrets are actually quite self-aware, they just don't display it often because they're doing their job properly.

Caroline's fate

 * Why is the fandom so desperate to keep Caroline alive? Caroline obviously didn't want to be stuffed in an AI and being preserved really feels like a Fate Worse Than Death. Isn't it better to let her at last have her rest, and to not completely ruin the point of the Broken Aesop by giving GLaDOS her newfound morality?
 * People get attached to characters; He's Just Hiding is hardly a new phenomenon. We're clearly expected to believe that Cave Johnson is dead yet there's tons of WMG that his personality is still around somewhere in the mainframe or one of the spheres.
 * The game also throws out a few hints that Caroline's not completely gone, most notably in the ending song where it's explicitly stated that "Caroline is in here too" and that GLaDOS still feels guilty about her treatment of Chell. Whether one accepts the song as canon or not, it's not hard to see where people are getting the idea that the Broken Aesop was meant to be subverted.
 * My view of the nature of Caroline makes "GLaDOS deletes Caroline" an impossible scenario and thus necessitates that she is lying. Specifically, my view is not that Caroline is a part of GLaDOS. She is GLaDOS. She's just trying to get rid of Chell at that point. She may have metaphorically deleted Caroline - ie, intentionally going into denial about her old identity and repressing her empathetic character traits.
 * I don't think GLaDOS is Caroline - when you think about it, they're really nothing alike save for their voice, liking of Cave, and love of doing science. Caroline lives in GLaDOS's brain, as GLaDOS herself stated, and mentions her as separate in Want You Gone. She just got to walk a mile in Caroline's shoes (so to speak) down in Old Aperture. Plus, as a quote from Ellen McLain herself: "I think GLaDOS likes Caroline".

Neurotoxin

 * It's kind of a big thing when you shut down GLaDOS's neurotoxin production. And it's not like you just flip a switch, you cut the neurotoxin tubes and implode the entire producing unit (or whatever that big thing is). So... where does Wheatley get it later?
 * There's enough time between then and now for him to have restored it. Wheatley does mention that GLaDOS can fix it given time. He had that time.
 * But he's also Wheatley.
 * So? He may be stupid, but he's not a drooling brain-damaged imbecile. He intentionally chose to fight Chell in a way similar to her original fight with GLaDOS, which included the neurotoxin. Of course he'd fix it.
 * I'm in favor of this theory, but it does raise another question: If he fixed the neurotoxin generator, why didn't he also fix the turret line?
 * Because he's Wheatley.
 * Maybe designing/creating/'training' the frankenturrets distracted him-- it could be that he was using turrets rescued from the redemption line to build them, and just didn't question the fact that they were perfectly functional (which would have been the ideal for the experiments, anyway).
 * He did fix the turrets, but he forgot to throw out the old ones. He brings out some functional turrets later on. Also, because he's Wheatley.
 * Thank you! Someone who also questions the neurotoxin usage!

Falling for a long time

 * When you fall down that shaft for a kilometer or so in Chapter 6, you end up crashing through a few planks of wood before (presumably) passing out and hitting the ground. You wake up lying on your back. Now, if long fall boots work the way I think they do, then either Chell managed to land on her legs and stay like that in her sleep, or she has a very, very strong back... any explanation?
 * She could have absorbed the shock from the boards and then fell the short way to the ground positioned in a way that the boots absorbed a lot of impact, but there was still enough to knock her unconscious.
 * I get the idea that Longfall boots work whether you're conscious or not.
 * Indeed, in the pre-release Boots trailer, Cave mentions that the user is actually incapable of not landing on their feet, even if they try.
 * Maybe she got knocked out by the boards hitting her in the head, landed on her feet anyways, but then simply tipped over backwards.
 * People in media survive absurdly long falls all the time. No need to invent crazy justifications.
 * While we're on it, how did GLaDOS survive that fall? Even if the Long Fall boots broke Chell's descent, GLaDOS is just a potato. She ought to have been mashed potato nanochips.
 * Maybe the bird caught her?

Pressure

 * Maybe I'm getting all of this Moon thing wrong but...the pressure difference between the chamber and the actual moon is enormous. Even if air could have let Chell breathe, as hard to believe as it is, the pressure loss would have still caused her blood and bones permanent damage, right? Alternatively, how can you explain she could both breathe and hold onto an object when she was in outer space.
 * I don't think it's that hard to believe that she could hold her breath before being sucked out. Plus, I think this is just sort of Handwaved away - she's survived much worse (Repulsion gels, being flung about, sucked through Portals, plus the psychological impact that GLaDOS has had on her), I don't think it's too crazy to imagine that she could have the willpower to last in space for a few seconds.
 * In the comic, Chell's file says that she is tenacious to a fault. Perhaps she really is such an impossible badass that the vacuum of space does nothing to her. Also, GLaDOS's "adrenal gas" couldn't have hurt things.
 * It takes around thirty seconds for exposure to vacuum to cause permanent damage, assuming you don't hold your breath, and Chell wasn't out for that long. Besides, GLaDOS could have provided medical attention while she was unconscious.
 * Chell is never exposed to the vacuum of space. With all the air rushing past her it's more like she's in a wind tunnel. She can hold her breath while that happens.

GLaDOS' redesign

 * Why does GLaDOS' head look different between games? See here and here. I mean, I like the new one better and everything, it just seems strange to give a major character an inexplicable change in appearance between games when she's been lying there undisturbed for the entire time between games.
 * In the Lab Rat comic Doug clearly says that even though the queen is down, the hive is still kicking. It's not out of the question that they moved her pieces back inside and updated her head for some reason.
 * Well, yeah, but still, they'd replace her head but leave her turned off? I'd be willing to accept a visual retcon like they did with the various cubes, doors, elevators, etc., but still, it seems strange.
 * ^ it is a visual retcon, just like why Chell suddenly looks 20 years younger and wears make up.
 * It isn't a visual retcon, in the comic you see GLaDOS before she killed all the scientists, and she looks the same as she does in Portal 1. I think the reason they changed her head is that, quite simply, the old one was destroyed. You can see it smoldering in front of you at the end of Portal 1. Presumably she was backed-up somewhere in the facility and some cores rebuilt a body and loaded her into it, for whatever reason.
 * You can also see GLaDOS with her original head in Rattman's artwork next to where you find the portal gun. It's even possible that the new head is just the old one with the covering around the eye removed (although retconned to white).
 * But her original head is still rounder-looking and smaller, even if you mentally remove the covering.
 * Maybe we're trying to come up with a reason for something that Valve never created a reason for.
 * I always thought that maybe her head was extremely damaged and maybe the nanobot work crew rebuilt it to the new design but weren't able to power her back up.

GLaDOS controlling the claw

 * Where did GLaDOS get the big claw thing at the end of the final battle? There wasn't one of those things that was under GLaDOS in the core swap scene. Also, how did she control it? She wasn't hooked to the mainframe and had no way to because, again, there wasn't a core swap thing under the mainframe. ALSO, where did her old head come from? It wasn't there before.
 * The claw? It was probably there, but wasn't used the first time. Controlling it? Remember how the cores from the first game only stopped affecting her after you destroyed them? She was already linked to her body by some temporary/not very powerful remote connection just like the cores. The head? It was probably still in that area with the claws from when Wheatley put her in a potato. And, before someone brings up how she got back into her head, remember when she says "I already fixed it!"? It was a fairly fast process, and Wheatley transferred her to the potato in just about the same amount of time, if not less.
 * The mainframe area is highly reconfigurable. Wheatley probably had the claw stashed somewhere out of the way (note that it's also present when you repower GLaDOS). It's rather ironic because it would have made all the Final Boss battles rather one-sided.
 * Isn't it the claw she dangled the Adventure and Fact spheres from?
 * Nope, that's the one she crushed Wheatley with. The big one is present in the control room before the final battle (Wheatley punches-you-into-this-pit with it.)

Time between Portal 1 and 2

 * Something that's been somewhat confusing to me: Many people seem to be confused about how many years have passed before Portal 2 begins. Some think it's only a matter of days, some only a few years, some believe around 30 years, and some 300 (I personally believe the last). Here's what I can't wrap my brain around... how could someone think hundreds of years haven't passed between Portal and Portal 2, after taking into account the complete decay the facility has fallen into? Plants don't grow into infrastructure and buildings don't fall apart after a short amount of time. It takes a long time for that to happen. In addition, when the AI wakes you up for a second time, the machine stutters when saying the number 9, implying that it surpassed its upward counting limit loooong ago, which may even be higher than 300 years. Finally, didn't Valve more or less confirm that its been hundreds of years?
 * It's hard to say, really. The problem with assuming 300 years is that you run into serious Ragnarok Proofing issues. For example, take the Bring Your Daughter To Work Day exhibit. Even 30 years would have caused the potato batteries and the poster boards to crumble into dust. Most plastics used in the construction of the facility would become brittle and crack. Electronics would decay and fail. In 300 years, the structural metal would have long since rusted into uselessness and the entire facility would collapse on itself. Then take the old Aperture Labs facilities. No AI was maintaining them, and they still have working lights and electricity. These contradictions make any sort of effective dating impossible.
 * Keep in mind, however, that even though they had no AI, they DID have prerecorded messages to use so that testing could continue, even during post-apocalyptic conditions. Not only that, but all Aperture Science facilities are able to run at as low as 1.1 volts. In addition, even though no AI was maintaining things in real-time, the personality cores activated after GLaDOS was killed most likely kept everything in acceptable working condition, at least as well as something with no arms could. So the facility was far from abandoned during that time. As far as the Condemned Testing Labs go, it's not impossible that the tech down there could run at 1.1 volts too.
 * A book I read, Earth without men I think was the title, goes out of its way to explain why pretty nothing created with technology from the last 200 years would last very long without anybody to sometime add a coat of anti-rust or change the de-moisturizer. I'm strongly inclined to believe that 30 years is more than enough to acount for the state of the center. Note that you can see sunlight entering the rooms in the very first levels, which means holes leading to the surface, which mean flood at the first rain. Ever saw a house that's been flooded? I did. At best, the paint on the walls is screwed, at worst, the walls themselves take the hit and become structurally unsound. From being immerged a few hours. I'd already consider the fact that there is working equipments in the upper layers of the center thirty years after the Seven hour war a near miracle, so 300 years would be pushing it way too far. Hell, where did the remaining equipment get its power? No battery could ever last 10 years, fuel become unusable after a few month, nuclear reactors goes critical if not constantly tended to, and even then their fuel would never last 20 years.
 * Nope, 300 years. The state the facility is in is far too bad for a mere 30 years to have passed. Not even mutant super potetoes could cover that much of its insides in vegetation in just 30 years, especially when you consider just how mind-bogglingly huge the facility actually is. Furthermore, 30 years isn't long enough to provoke the kind of comments Wheatley and GLaDOS make on how long you've been gone. 30 years is pretty long, but it's not mind-boggling. Three centuries, however, is quite staggering. As for what you said about the technology, yes, okay, but that's regular technology. It's like you haven't looked at any Aperture tech at all. The stuff is specifically mentioned during the game to be apocalypse-proof in a variety of ways and it's quite preposterously durable during the first game, too, what with it being able to survive temperatures of up to 4000 degrees Kelvin. And you claim that no fuel cells last that long in real life? In a world that has portal technology in the fifties? As for the reactor, you don't know how much extra fuel it had. Also, right at the beginning of the game the automated messages tell you that the reactor is about to go critical, so presumably the emergency sub-systems that took care of it finally gave out after all those years and would have taken out everything if GLaDOS hadn't been awakened. Basically, everything in either game shows that, while they lacked common sense and any kind of moral judgment, Aperture built their equipment to last.
 * This theory falls apart a bit when you take the historical sections of the facility in to account. In the 1950's section we see cloth, wood, and even paper that is in remarkably good shape for 80 years, let alone 350. And even if we were to assume that all of these materials are long-lasting synthetics invented by Aperture (an Aperture who had barely graduated shower curtain manufacture at the time, no less,) that doesn't explain the foreign materials found in the trophy case, such as a newspaper. Also problematic the fact that Aperture didn't invent AI until well after the lower levels were sealed. Not only do they have no real reason to maintain the electronics and stuff in the older parts of the facility, but they lack any discernible method to boot. Well, perhaps except for the one possible saving grace for the "300 years" theory: the briefly-mentioned nanobot work crew. "Jerry" and his pals could be invisibly refreshing the perishable materials in order to keep the entire facility from rotting/rusting away. I admit both theories require some leaps in logic, but I still tend to lean toward "30 years" because it makes more sense story-wise in relation to future Half-Life crossover.
 * But nothing said to you in the game gives a clear indication of just how much time has passed. The wake up voice recording was glitching out, GLaDOS lies to you all the time, and Wheatley is a moron. Anything they say has to be taken with a grain of salt.
 * I would be more accepting of a 300 years time span if the facility hab been made entirely of glass and plastics, two materials that Gaia Vengeance tend to break its teeth onto. And again, holes in the roof, meaning the facility is exposed to everything nature can throw, from dirt to water, insects, animals (that bird must come from somewhere) and plants(those potatos plant must have acess to natural light). A devastating combo for any man-made construction.
 * The old facility throws all this on its head anyway, as I pointed out earlier.
 * Those who talk for 30 years don't seem to take into account all the maintenance A Is and self-repairing systems implied in the game. The place has deteriorated enough that it takes personal interference from GLaDOS to fix things up again, and she manages to get the place close to pristine condition in the matter of hours again.

The moon isn't flat for portals

 * I'm curious how in all the questions about the Moon portal this one gets omitted. Seeing how the portals can only be placed on perfectly flat and smooth surfaces, how can you place one on the Moon surface that is most obviously neither?!
 * Cave said that lunar dust is uniquely suited to conducting portals. So who says it has to be flat and smooth?
 * The moon is enormous. Have you ever seen a space walk? On a human scale, the surface of the moon is pretty flat. It's not quite as flat as, say, the Earth, but still.
 * Not to mention the portal hit at an Apollo landing site. And what is the first primary key feature that would have been looked for when evaluating possible landing sites?
 * The portal projectile somehow has the ability to autocorrect and find a flat surface when you fire just off of one. There is a lot of distance available for the projectile to turn in when you fire at the moon, so it could have sought out a nice, flat surface.

Logic bombs

 * After GLaDOS's Logic Bomb fails to fry Wheatley, she says "That almost killed me!" Now, the technical justification for a Logic Bomb is that it sends the AI into an infinite loop (to be precise, infinite recursion) trying to work out the "correct" answer, pegging the CPU and ultimately overloading it, but if said AI is intelligent enough to understand that there is no correct answer to a paradox, then such a disastrous code path should be entirely avoidable.
 * The Coconut Effect
 * Personality Constructs seem pretty close to being human, so it could be that even though GLaDOS knows there is no answer, she subconsciously tries to work it out anyway and gets trapped.
 * I'm not a mathematician, but there are statements which can't be proven. There are also statements that can't be proven to be impossible to prove, etc. It may be that logically proving certain paradoxes are, in fact, paradoxes is impossible. An AI, no matter how complex, has to be built on logic. If it's impossible to determine a paradox is paradoxical, then the program tasked to determine which queries are worth considering will also enter an infinite loop - because it can't determine that it's indeterminate. "This statement is false" is not an example of such a paradox, since simply using the routine "If A=> not A and not A => A, quit" would resolve the issue, but they may exist.
 * This, I think, is a variation on the Entscheidungsproblem, which basically says that there exists no algorithm that, given the description of a formal language (e.g. arithmetic or boolean logic) and a statement in that language, can determine the truth of the statement.
 * But on the other hand, computer programs nowadays do have safeguards against paradoxes in the form of specifications (like treating a logical contradiction as a boolean false), and things like any given variable only holding one value at any point of time (so that variable A can't be both true and false at the same step in the algorithm). A kind of fork bomb—i.e. a process that can duplicate itself or create new running processes infinitely—would probably be a better choice.
 * If I can math geek a bit: even more subtle, there are mathematical statements that ARE true, but which can't be proven true. One particularly famous example involves a specific function f(x, y) and a specific number n where we can easily prove "f(1, n) does not equal 0", "f(2, n) does not equal 0", etc. for any particular integer but there's no way to prove that "for all x, f(x, n) does not equal 0" short of an infinitely long proof that goes through every single integer individually. So a computer trying to prove "for all x, f(x, n) does not equal 0" would never reach a contradiction (since the statement is true), but would also never finish the proof. Bonus amazing fact: the function f in question can be interpretted as "this function is zero if and only if the statement with number x is a valid proof of the statement with number y" and n just happens to be the number for the statement "for all x, f(x, n) does not equal 0". In otherwords, the statement is asserting it has no proof, or more generally... "THIS! SENTENCE! IS! FALSE!"
 * I just added this to the WMG page, but: Can't you just imagine Cave Johnson saying "Whaddaya mean paradoxes don't harm our AIs!? I want you to make a special paradox-detector that'll fry every circuit in its brain, and I want you to put it in every single one of our AIs, on the double, or you're fired!"
 * Actually, I can imagine that quite vividly, and for a moment I even wondered to myself if he ever actually said "I want you to make a special paradox-detector that'll fry every circuit in its brain".
 * Adding to the above theory -- think about what kind of robots we're talking about here. These are Aperture robots. We're talking about robots built by people insane enough to believe you can do anything with anything if you bend the rules and avoid awkward questions. Every single mechanism in that place, sentient, sapient or otherwise, is devoted to science and discovering how it works. For robots whose entire existence is devoted to finding answers, a paradox is not something you can just say no to. These robots are literally COMPELLED to find the answers to impossible problems. Even if you somehow find it hard to believe that every robot in the place functions as such, it's more than believable that GLaDOS herself -- the most intelligent Aperture AI ever built and created with the explicit purpose of overseeing and masterminding every future discovery of the facility whilst ensuring that research continues with or without the lab or even society being functional -- finds the threat of an unsolvable paradox dangerously life-threatening.

Orbiting Wheatley

 * The final scene where, along with a little bit of physics, can be used to estimate Wheatley's mass. Unfortunately it also implies that Wheatley weighs something like 100 million tons. What's up with that?
 * It's a stealth pun. Wheatley has a lot of mass because he's so
 * If Wheatley really weighed 100 Mt (or Tg), if any other Aperture technology wasn't as massive, he would obliterate Management Rails,, and if he was given enough velocity he would smash right through the entire three mile deep facility. As Thinking With Portals forum said, "Do Wheatley and the Space Sphere have enough mass to orbit each other? No. Why are they doing it in the ending video then? Because it was funny.
 * What if the cores have some net charge between them? That would be enough to keep them in orbit at a much shorter distance.
 * I don't remember that scene, but is it possible that they're not actually orbiting, but the camera is just circling around them, making it look that way?
 * The Space Core could also have some system for direction control in space (since he was designed for operating there) and is just staying near Wheatley out of habit/companionship.

Chell's brain

 * Is Chell brain-damaged? There's the gag at the beginning where you "Press A to Speak" and she jumps, but aside from that she never speaks once in the game. The Word of God reason for her being mute in the first game is supposedly as to not give GLaDOS the satisfaction, but there are long stretches of this game where GLaDOS cannot hear her or where speaking to Wheatley would make sense. I understand its a Valve tradition, but considering how well-written and acted their other characters are, the mute PC stands out more and more IMO.
 * She might be mute because she never learned to speak.
 * She obviously learned to write if she made that science project. She has to know. She just doesn't.
 * Yes, she is brain damaged. I really don't understand how you can be confused by this, Wheatly said it was normal for people in suspended animation for more than a few months to suffer brain damage (and Chell was under for years), and the whole "jumping instead of speaking" gag made it pretty clear that Chell wasn't an exception. Plus both Wheatley and GLaDOS believe it to be true and continue making comments about it throughout the game. I thought it was a really clever way to justify having a silent protagonist (sure beat's Freeman's unexplained muteness). Look up Dysarthria if you want to know more.
 * Jossed by Erik Wolpaw. He said that the intent at least was that Chell just isn't bothering to talk to the robots.
 * Pretty sure that explanation only applied to the first game, when the only other person to talk to was a homicidal robot intent on tormenting and killing her. It's understandable that Chell might refuse to talk to GLaDOS in that situation just out of stubborn resentment. It doesn't explain why she wouldn't talk to Wheatley though.
 * After dealing with GLaDOS, she's probably not terribly trusting of artificial intelligences, no matter how friendly they may seem. She also may just have gotten used to not talking. As to why she didn't give Wheatley the paradox when it became clear that GLaDOS couldn't, it's noted in the Ratman comic that she's abnormally stubborn. She probably noticed how Wheatley basically had a total personality shift, and still believed he was salvageable.
 * Emancipation Grills. They have been know to emancipate dental fillings, tooth enamel, teeth, and now ear tubes. Meaning she might as well be deaf and mute.
 * She's definitely not deaf, because the player can still hear what she hears. Maybe the grills did make her mute though.
 * Even beyond brain-damage (which is, let's face it, a probability), her silence towards GLaDOS can probably be explained by an understandable reluctance to engage in pleasantries with the intelligence that forced her to literally jump through hoops for her own sadistic amusement. As for Wheatley, even when he's 'good' this can be easily be explained by the fact that when he's around her, Wheatley barely shuts up long enough to allow her to get a word in edgewise anyway.
 * There's no way Chell is brain-damaged, or at least not as much as she would have to be after however long she was in suspension. She never could have done the things she does in the game otherwise. As for the jumping instead of speaking, that's obviously just Rule of Funny.
 * Not speaking to GLaDOS can be explained by the reason above - not wanting to talk to the sadist who spent however long testing, insulting, and trying to kill her. Wheatley looks pretty much identical to the cores Chell incinerated except for the eye color - she probably started out not trusting him, and later he turned evil and she didn't talk because of that. She may also just be a naturally quiet person. (I imagine the jumping was a way to acknowledge Wheatley but mess with him at the same time. Chell might be an abnormally stubborn person, but that doesn't mean she can't have a sense of humor.)

How does uploading a mind work?

 * Cave said something about "putting a brain into a computer," but how exactly did that work? Is GLaDOS the surviving remains of Caroline's mind and consciousness, or was her personality simply based on an exact copy of Caroline's? Cave may have wanted the project to survive, but I don't think he'd made Caroline suffer such a terrible fate, if the former case is true.
 * Cave outright says to force Caroline to undergo the procedure.
 * There's unused audio recordings of Caroline screaming and begging Cave Johnson not to put her into an AI.

Every turret becomes defective

 * Why does sabotaging the turret production line replace every functioning turrent with a bad one? The factory runs nonstop, so GLaDOS should still have an enormous stockpile of functioning turrets to draw from even if she can't make any new ones.
 * One of the dev commentaries mentions that the turret production line actually ends with all the newly packaged turrets being unboxed and then scrapped for parts to be reused at the beginning of the line. So it would seem the only way for GLaDOS to get turrets for tests and traps is by removing them from the line before the end, and since she has been dead she hasn't had a chance to stockpile any.
 * The bad turrets in the line are also destroyed, and when Chell sabotages the line the good turrets are considered defective.

Portal gun invention date

 * When was the portal gun invented? Several times in the game and tie in comic, Aperture scientists express jealousy and respect towards NASA for beating them to the moon. But the old sealed off testing courses are clearly designed to be solved with portal technology, despite signs dating them to the 1950s! As seen at the end of the game, portal technology makes visiting the moon a cakewalk, so shouldn't Aperture have won the space race?
 * The scientists likely had no idea that the moon was portal conductive until after they created the conversion gel which was in the 70's.
 * The portal maker was invented in the 50s. The very first old-school test sphere has a sign that says 'This can't be solved without a portal device', showing one the size of a big backpack in a stylized drawing. But as mentioned several times on this page, they didn't see it as an end itself, they saw it as a testing device for the 'useful' things like the buttons and gels. There was no way to get moon rocks until after NASA landed on the moon... and no way to find out they were good for portals until then.
 * But why didn't they just shoot a portal at the moon even just for kicks or to see what would happen?
 * They owned a technology that could revolutionize the world, and for 50 years they used it to test useless dietary aids by having people jump onto them from great heights. They were handing these trillion dollar devices out to bums for god's sake! The sheer stupidity of it boggles the mind. Also, considering how crazy everyone at Aperture Science is, I'm kinda surprised no one ever tried just randomly firing the gun at the moon.
 * Or maybe they did try, but it went horribly wrong and that was behind the "missing astronauts" thing.

The Borealis's drydock

 * The Borealis's drydock is found several kilometers underground. HOW DOES THAT MAKE ANY SENSE?!
 * The Borealis has some sort of advanced technology that is useful against the Combine, my guess is teleportation or larger portals or something, but in any event it didn't sail out of there.
 * Maybe it didn't, but that doesn't answer the question of how it sailed in there to begin with.
 * They probably built it there.

Portals on white surfaces

 * This is something that isn't explained in either game, why do the portals only work on white surfaces? In the second game before you can shoot a portal in certain places you have to make sure there is white paint covering the surface.
 * Some materials conduct portal surfaces better than others. The Conversion Gel basically turns everything it covers into a valid portal surface.
 * The conversion gel is made from moon rocks, which it turns out are a fantastic conductor for portal surfaces. This is mentioned several times throughout the old Cave Johnson testing area as foreshadowing for how the final boss fight ends. It's sort of implied that after it's invention in the 70s they started using the white conversion gel to paint the walls, so it's not that portals only work on white surfaces, but that they work best on paint that contains ground-up moon rocks, which happens to be white.
 * All the portal walls are white. Non-portal walls are black. It's a reasonable assumption.
 * Since you are in TEST chambers, it seems reasonable to think those were designed to be Color Coded for Your Convenience (in other word, it's a justified trope)

Wheatley's bars

 * Relatively minor, but at the end of the game, how does Wheatley get his bars back? All personality cores have those two bar things above and below their "eyes," and Wheatley's are taken off as part of the procedure to be added onto GLaDOS' body; the developer commentary even notes that he can move around more in this state. How, then, does he get them back by the end sequence where he wishes he could apologize to Chell. We see the entire process by which he gets into space.
 * He has them even before he ends up in space, Chell is hanging onto him by them. They were probably retracted behind his head where you can't see them, but when his cable became detached they came out again.

Revamped rooms

 * Apparently, the facility can only be altered when some entity (e.g. GLaDOS or Wheatley) is controlling it. After the events of the first game, it's more than implied that nobody was tending to the facility (even as Wheatley puts it, you killed GLaDOS, then nothing happened, then you attempted to escape with Wheatley), so naturally the whole place fell into disrepair. My question is this; how did the original testing track change so much if there was nobody around to change it? Two of the chambers have been completely revamped, two entirely new chambers seem to have found their way in, one seems to have been fused with another, and yet another one doesn't even come back into play until after you've revived GLaDOS. Then you have all the elevators getting completely replaced. Assuming that the "announcer" at the beginning of the game has no direct control over the facility, how and when exactly did all those changes get made?
 * Those could be different chambers that already existed by the events of Portal 1. You enter an elevator at the end of each chamber -- it could simply have taken you to different ones.
 * Or, if you do not want to accept that it just has always been that way, perhaps it was a leftover from the storyline where there were more cores then just Wheatley, and they were running the facility, like the big Game Informer article said.
 * The different elevators are Art Evolution. The developer's commentary explains that there is no in-game reason for the elevators to be different, they just wanted to redesign them. Same story for the new Material Emancipation Grids.
 * I assumed that the facility did continue to receive some upgrades after the events of the original Portal. While GLaDOS was dead, other, unseen robots did continue to manage the test chambers as best they could, i.e. installing more movable panels, new elevators, etc. Eventually they stopped, possibly due to attrition as they broke down or from being unable to handle any problems that fell outside their programming. It would be like the entire management of a company vanishing one day. The office drones would probably continue doing their work for a while, even managing to complete previously-assigned long-term projects, but without any direction the company would eventually fall apart.

GLaDOS's claws after reactivation

 * Where did GLaDOS get these two claws with which she lifts Chell and Wheatley after being reactivated? She didn't use them in the first game, even though they could have helped stop or kill Chell right then and there, nor does she or Wheatley use them when revisiting the chamber later in the second game.
 * She used the claws in other places. Maybe she had more freedom now, or the damage to the room allowed them in.
 * She actually did use her claws in the first game. Maybe the Morality Core affected her ability to use them (just like it affected her ability to turn off the Rocket Sentry), or perhaps she was just that confident that the neurotoxin would be enough to finish her off. She's a sadist, so maybe she preferred the idea of watching Chell suffer (death by neurotoxin is not a pretty sight) to killing her quickly and simply with claws.
 * When did she use them in the first game? I've played Portal 1 a lot but I don't remember there being any claws like that.
 * The claws are in the game. They aren't animated, but they're implied to be how GLaDOS gets the turrets around the complex.

Cores exploding

 * If all Aperture technologies remain safely operational up to 4000 degrees Kelvin, and the Companion Cube survived, why did the cores explode? If they survived, why have a furnace at all? And why did GLaDOS explode when they were removed, as the Lab Rat comic and sequel describe them as just voices in her head?
 * Maybe they outsourced for some materials. Some things they bought from other companies don't have such high tolerances and explode under extreme heat. The Aperture records simply don't take that into account.
 * The fact that there was an Emergency Intelligence Incinerator in the same room as a potentially-hostile AI shows some astounding forethought on Aperture's part: they either deliberately built the cores with combustible materials, or the incinerator was hotter than 4000K. Either one would justify the cores' explosions.
 * Aperture continually lied to its AI (They told me if I ever used this, I'd die. They said that about everything!) So the hardware could get recycled (in the same way that the turrets are recycled) and GLaDOS etc only think that the cores get destroyed.
 * Maybe the cores have a remote connection to her until they're destroyed? That could explain the tractor beam-like thing.

Reasoning behind obstacle courses

 * Why does Aperture Science test their products by incorporating them into elaborate obstacle courses that require the ability to warp space to navigate? If they wanted to test repulsion gel, couldn't they just throw stuff at it, or tell people to jump on it if they really must have human testing? Why is it necessary for the test subjects to solve a dangerous puzzle while they're jumping on it?
 * That would be too rational for Aperture Science. Plus, if you're testing the gels and the portal gun, why not combine the chambers and test both at once?
 * C'mon, this is Aperture Science we're talking about. At this point it is utter foolishness to ask, "Why would they achieve Goal A in this convoluted, inefficient way, when they could have done it in this obvious, simple, effective way?" Utter foolishness.

Human testing

 * According to Cave Johnson's prerecorded messages, human testing nearly bankrupted Aperture Science. They started out testing astronauts, Olympians and war heroes in the 50s, but thanks to expensive lawsuits and government fines, by the 70s they were hiring bums off the streets and by the 80s they were reduced to forcing their own employees to "volunteer" for testing. In fact, in one of Cave Johnson's last messages he states that Aperture is phasing out human testing. So why is that in the modern facility the game starts in, not only are they still testing on humans, but According to Wheatley, there were 10,000 of them being held in the Relaxation Center (until they all died under his supervision)! And in co-op mode the players find a huge vault of humans in cryogenic sleep who are still alive. So why is Aperture Science still performing human testing, and where did they get all those test subjects from?
 * Aperture was going to phase out human testing -- while it was still run by humans. Once GLaDOS took over, she presumably saw no reason to carry on with those plans. As for the test subjects in stasis, presumably they were either Aperture employees or people visiting the facility, captured and suspended by GLaDOS.
 * The several hundred humans frozen in the co-op vault I can believe were Aperture employees. Each is given a scientific job title as they're scanned during the credit sequence and GLaDOS seems to know personal details about most of them. But what about the 10,000 humans suspended in the relaxation center where Chell wakes up? Where did they come from? I have a hard time believing that Aperture had that many employees, especially considering Cave Johnson's complaint about how employee retention had plummeted after "voluntary" employee testing became mandatory.
 * If you look closely at some of the stickers on the relaxation vaults (you can see them if you zoom in during the ride in your hotel room at the beginning) the packing dates are from the 1970s. I wouldn't be surprised if a lot of them were homeless people who were somehow convinced to do that.
 * This was in the 80s. Aperture obviously got back on its feet between then and the first Portal.

Condition of the old courses

 * How the heck are all the old sealed off testing courses still in such fantastic condition? Seriously, the first few modern facility test courses you visit are more broken down despite having more advanced building material, self-repairing technology and the once-off mentioned nanobot "work crew" to keep them in shape! But none of those things are present in the old Aperture. It's amazing that they still have working lights down there after 50 years (plus however long Chell was sleeping), let alone elevators and pump stations. There's not a spot of mold or dust in the various offices you come across, there are paintings and posters in mint condition everywhere, and wooden boards that haven't warped or rotted all over the freakin' place. Yes, there are rusted and broken catwalks everywhere and the ground floor is covered with trash and mud and the elevator to the surface is shut down, but aside from those the place is for the most part so clean and organized and functional that I simply can't believe it's been abandoned for a year, let alone half a century.
 * I got the impression that the old chambers were deliberately preserved, not just passively let to rot like it was the case with the modern facility. Thus they could have taken the measures to prevent decay, such as reinforcing the walls and covering the furniture in whatever protective stuff they have at Aperture. They simply shut the power and gel flow down and let the area rest until Chell reactivated it. Notice also that while the test chambers and offices are well-preserved, the vast space between them isn't; Aperture probably didn't bother taking measures to preserve the maintenance areas while sealing them off.
 * Cave Johnson says that the Enrichment Spheres are coated in Asbestos to keep the rats out. Kinda flimsy, but if he covered them with enough of it, it should hold off most of nature for at least a little while.
 * Deep underground the chambers wouldn't be exposed to a lot of things like rain, wind, plants, and sunlight so it would last longer even setting aside Aperture's obsession with Ragnarok Proofing. That said, it is significantly damaged, there are many areas where you have to make portal jumps because walkways have collapsed.
 * It's implied that even a lot of the upper test chambers are underground. With the chambers from Cave's era, they're so far down they're practically like preserved fossils.
 * Keep in mind, though, that they're still in a salt mine, and in a planet that was in the process of being taken over from below by burrowing Antlions (unless the Antlions were only introduced to the eastern hemisphere).

Position of the earth and the last portal

 * At the end, when Chell portals to the moon, the two surfaces the portals are on are, for all intents and purposes, parallel to each other. However, when Chell looks at the earth, she's not looking straight up, relative to the moon; she's looking sideways. Did the moon suddenly rotate ninety degrees while we weren't looking?
 * Or Chell moved her head.
 * It can't be that; the surface of the moon is still visible when Chell looks at the earth, even though it shouldn't be.
 * It's possible that the portal didn't land in the center of the visible side of the Moon, but closer to a polar region. After all, the game doesn't take into account where you actually aim the portal gun -- it doesn't even care what color the portal is!
 * But the twinkle before you get sucked out is clearly not at a polar region.
 * What if the portals don't just warp you through space - they warp you through spacetime. And the time dilation is in some way proportional to the distance involved. Then, the time difference from one portal to the next is unnoticable across a few metres like during most of the game, but over a quarter of a million miles, it's enough time for the Moon and Earth to turn a significant amount.

Astronauts

 * Where did Cave find any astronauts in 1952, nine years before Gagarin's flight in 1961?
 * He said they were "missing" astronauts. Possibly as in, really missing due to portal malfunctions. The term "astronaut" has also been around since 1929, so maybe it meant something else then.
 * Or the recording was not made once and forgotten at the time that that section was built, and what Chell hears is the last revision used for that section (when astronauts are around). The Borealis, assuming continuity with the blueprints from Episode 2, was far newer then its drydock when lost.

GLaDOS can't help you?

 * The bit about GLaDOS being unable to tell you the solution to a given problem. I don't get it; either the punitive shock is tied into the main core, in which case GLaDOS should have been unaffected; or, the shock is tied into all personality cores, in which case Wheatley should have known about it long before it became relevant. And in either event, GLaDOS is currently working with one-point-six volts; what energy could she possibly muster to significantly shock herself with?
 * Easy, it's a Hand Wave. They needed a reason she couldn't help you, and the other idea they had -- having her "puzzle solving memory" getting constantly pecked off by a bird -- wasn't technically feasible.
 * Presumably the shock is built into all personality cores to prevent them from helping test subjects solve the puzzles, and Wheatley would have known it if he had tried to help Chell before (and he didn't). Why didn't he know it? I see three explanations, all plausible: 1) He's Wheatley. 2) He did know, but just couldn't resist helping Chell to get her through the test chamber faster. 3) The most likely one, in my opinion: he didn't know about the shock because unlike GLaDOS, he was never meant to administer tests.
 * Or 4) He's Wheatley
 * They probably told him he'd die if he ever helped a test subject solve a test, and finally catching on, he presumed that warning was rubbish like all the other things they told him would kill him. Hilariously, turns out that one was partially true.
 * Note that whenever she uses too much energy, she temporarily shuts down. It's possible that it would start to shock her, only to instead shut her down, which would be more of a hindrance because she's gone for a while.
 * There's also the fact that the puzzles you do with her are handmade by Wheatley either from scratch or by combining multiple test chambers together, so she would be trying to figure them out as much as the player since it's likely she knows the answer to one component or one chamber, but not when the components are put together in a new arrangement she hasn't seen before. In a way when it's mentioned, it's GLaDOS telling you why she couldn't have helped you before even if she wanted.
 * Maybe she wasn't entirely sure if it would shock her or not, but didn't want to risk frying her potato (which could kill her).

Portals break thermodynamics

 * How in the hell does this get around the First Law of Thermodynamics? Place two portals, one exactly above the other, and drop something in it. Watch as it essentially turns into a free energy device. Where on earth is all that energy coming from?
 * Gravity?
 * You might note that this has been commented on many, many times. In fact, I don't even see the point in asking, given MST3K Mantra.
 * Creating portals changes the topology of space around the them. You could come up with a physics-y handwave-y solution involving Noether's theorem (which says that conservation laws, such as the conservation of energy, are caused by symmetry, and breaking this symmetry destroys your conservation law) if you were so inclined.
 * It's not really free energy, merely a very efficient method of using gravity to transfer kinetic energy from the planet to the falling object. If you placed two portals inside an airless tube, and set an object in an "infinite" fall, the object would accelerate indefinitely, and eventually reach relativistic speeds requiring enough force to accelerate further that the earth would start pulling itself out of its orbit with its own gravity via the "falling" object. This would only be possible if the airless tube was constructed exactly at the geographic north or south pole, however, or the earth's rotation would make falling at relativistic speeds impossible. Factor in air resistance and all the kinetic energy is dissipated in a closed loop that doesn't affect the earth's trajectory through space... I think... Someone should do that math on that.
 * The problem is moving upwards in a gravitational field, you are gaining gravitational potential energy. This happens from moving from a low-placed portal to a high-placed one. It is unavoidable. Of course, we are assuming it does take zero energy to move from a low-placed portal to a high-placed one. Maybe the portal gun has a built in store of energy for this purpose.
 * You're failing to consider the energy required to keep the portals open. It's quite possible that any time an object passes through a portal, there's an increase or decrease in the energy draw that precisely offsets the gain or loss in potential energy caused by the displacement.
 * Perhaps as the objects continue to fall they lose mass so that overall their energy remains constant. (If you take an object from "infinity" to the edge of a black hole you extract mc^2 of energy from the system. Effectively the object loses its mass to the gravitational field. It's a lot more subtle than that, but then gravity has always been a subtle beast.)
 * The portals could establish some kind of hydrostatic equilibrium so that heavy things go down, light things go up, and it all balances out nicely. This would appear to be violated at the end, until you consider the differential gravity.

Hazards of the gels

 * OK, so Repulsion Gel "Does NOT like the human skeleton", and the moon rocks in Conversion Gel are toxic if inhaled, but what's the extra (that is, outside of what would happen if it was ingested) hazard of Propulsion Gel?
 * Not stated in the game. Could be anything.
 * Whatever the effects were, either Cave Johnson thought they were too minor to mention or too terrifying. I'm not sure which is worse.
 * I seem to recall it still being made of asbestos/causing no food whatsoever to be absorbed into the user's body.
 * Let's make one up! How about interior friction burns? Oh, and cancer. Everything causes cancer.
 * Running into a wall at 90 miles per hour seems like a pretty bad side effect.
 * I'm sure it stains pretty badly as well.

Keeping the Companion Cube

 * Why would GLaDOS keep ?
 * She didn't, it either survived on its own ("all Aperture technologies remain fully operation up to 4,000 degrees Kelvin"), or she just ...although that makes you wonder why she'd go to the trouble...
 * Or.
 * Word of God says that.

GLaDOS's lack of morality

 * Chell destroyed GLaDOS' Morality Core in the first game, which made GLaDOS go from "Use humans for test subjects" to "Kill all humans". How come when Chell reactivated GLaDOS, she didn't immediately try to kill Chell and instead sent her off to do more tests? Her body was repaired, but there was no sign that GLaDOS got a new Morality Core.
 * GLaDOS was going for a Fate Worse Than Death this time, as is plainly obvious. The facility is in ruins and her neurotoxin probably wasn't online at the time. She needed to have Chell waste time solving tests. Note that as soon as she has the place up and running again, she does immediately try to kill you.
 * Maybe the Morality Core didn't really work, GLaDOS just tricked everyone into thinking it did? The core never talks, and GLaDOS might have dropped it off on purpose so that Chell could destroy it, thus pretending to have more of a justified excuse in killing her. After all, even before you get to GLaDOS's chamber, she says "Turn back or I will kill you."
 * GLaDOS attempts to kill you once well before you get to her room in the first game. It's made quite clear that the Morality Core never really worked, all it succeeded in doing was preventing her from using the neurotoxin specifically.

Plumbing

 * How does the plumbing in Old Aperture still work? There's switches for the gel pumps, but nothing that controls water, so there's no reason to assume that it was ever switched off. So how have the tanks for the water in some of the test spheres not run dry over the course of god knows how many years? (Unless it's just purified sludgewater pumped in from the other spheres, which is gross.)
 * GLaDOS states that the air everyone breaths in the Enrichment Center is just re-used air. A similar process may work on water. Besides, we just know that it's a incolor liquid. It could be anything.
 * It could be that all that water is what's responsible for the filling of the Enrichment Spheres and the salt mine with sludge/acid/stuff. It might also explain why, if the top levels of the facility are exposed to the elements, rainwater doesn't flood the old testing tracks; it's just drained to the bottom (maybe as a way to drown off the Mantis Men?)

Chell getting recaptured

 * I can't believe nobody's asked the most obvious question: How did Chell get recaptured in the first place? GLaDOS was dead. Did those androids find her and put her in the Relaxation Vault?
 * The "Lab Rat" tie-in comic, available on the official website, explains this.
 * Even before that, a Portal update modified the ending, showing Chell get dragged back in.

Core corruptions

 * What is core corruption, anyway? In Portal, GLaDOS had several personality cores attached, thus was corrupted. However, you had to remove them to defeat her: Making her "pure" again.
 * The corrupted cores' behaviour make it clear that there's some fundamental flaw in their programming. Wheatley wasn't considered corrupt because his programming wasn't damaged, and he was still doing exactly what he was programmed to do ("be a moron"), and he wasn't totally messed up like the corrupted cores. GLaDOS, on the other hand, is very clearly corrupt. It's pretty clear that there's something wrong in her programming, somewhere.
 * I always thought that it referred to the fact that her cores were removed. GLaDOS had four cores hung on her mainframe in the first game. As you defeat her by destroying them, they obviously were semi-vital to her function. In portal 2, the announcer says that

Wheatley surviving getting crushed

 * So after he accidentally revive GLaDOS, she crushes Wheatley and tosses him aside. A few levels later, he's back and somewhat fine (if a bit twitchy), on his management rail again. How did he get back onto that rail?
 * Wheatley tells you himself, kind of, in Chapter 4. It's something of a Noodle Incident but apparently involves a bird.
 * Perhaps he has an identical twin.

Tone differences between Portal and Half-Life

 * Portal takes place in the same universe as Half Life. So how is it that Cave Johnson and Aperture Science can take Refuge in Audacity while everything related to Gordon Freeman, Black Mesa and City 17 are much more realistically treated?
 * Because they are different games that are related only by very broad-strokes Continuity Overlap. Valve is trying to keep them as separate as possible plotwise and thematically.
 * At least until ep3 friggin finally come out...
 * Or Half-Life 3. Either way though, I don't think we'll see Chell actually fight alongside Gordon Freeman or anything, since Valve is keeping them separate.
 * I don't think you quite remember how silly the original Half-Life was. Black Mesa was an absurd place with No OSHA Compliance through the wazoo.

Preventing the facility's explosion

 * The Lab is impending explosion since the beginning of the game. So when GLaDOS is revived, why didn't she do something about it while in control? Was her hatred towards Chell THAT distracting?
 * GLaDOS did fix the reactor after being woken up. It happens offscreen -- in fact, the supposedly impending explosion is never mentioned at all after the opening sequence so one wonders if Valve simply decided to ignore it.
 * And her hatred for Chell is also clearly not distracting her from managing the facility in the first half of the game anyways - GLaDOS leaves Chell alone in the testing chambers several times early on to go fix things.
 * Presumably GLaDOS was in the middle of ensuring the reactor core didn't explode at the same time as testing Chell, and had managed to prevent immediate catastrophe, but hadn't managed to sufficiently complete them before Wheatley overthrew her -- at which point, work on the repairs stopped as he devoted everything to testing, and he let what repairs had been done decay until they fell apart.
 * I thought it was one of those things that required regular maintenance to keep it in working condition (e.g. press a key every hour) and Wheatley just didn't bother doing it.

Wheatley hates moron more than idiot
"GLaDOS:"
 * Another thing that confused me. Wheatley didn't seem to care for being called an idiot, but being called a moron sends him flying into a rage! Is it just he's in a bigger body now or something? Is moron somehow worse than idiot? It's real confusing that a smaller word would be more insulting...
 * It's his Berserk Button. It doesn't have to be logical. His is the small mind that resents being reminded of the fact. It doesn't help that GLaDOS, once learning of that button, doesn't hesitate to press it at every opportunity.
 * Perhaps he doesn't understand what an idiot is?
 * Maybe, maybe not. He is actually referred to directly as an idiot ("Do NOT plug that little idiot into MY mainframe!") and replies rather succinctly ("No, you should plug that little idiot into the mainframe!"). You can insult Wheatley as much as you like, but the word "moron" does seem to be a trigger.
 * It's worth noting that the words idiot, imbecile, and moron used to have formal definitions, and under those, being a moron was actually better than being an idiot. So maybe he's so dumb that he's getting that backwards?
 * On a similar note, right before GLaDOS tries to hit him with a Logic Bomb, she says "Hey, moron!" and he just goes "Oh, hello." Why didn't he fly into a rage like he did the prior and subsequent times he was called a moron?
 * Because he wasn't expecting anyone to show up to talk to him, so he blew it off.
 * GLaDOS directly calls him the 'Moron Sphere,' maybe he doesn't mind other nasty names for the same reason a non-white person wouldn't mind being called 'honky' as much as other epitaphs.
 * Maybe he thinks 'idiot' is a designation, like how the Adventure Sphere's real name is Rick.
 * It should be noted that he is still affected by being called a moron in the last part of the game. The first instance, he does appear to shrug it off, but eventually he starts getting annoyed with it to the point he fakes reading Machiavellian works and plays classical music to appear intelligent.

Building the facility

 * Has it occurred to anybody else that Aperture labs is built upside-down? Seriously, the earliest parts of the complex are the furthest from the surface. It doesn't seem like an Aperture is incompetent trope to me because if that was true then they worked out exactly how much space they would need for the next 40 years.
 * Building up from the bottom is hardly unusual. What would be unusual is if they started at the top and built down.
 * That's how they would do if they built the base from scratch, but since they bought some abandoned mining complex instead, they already had the tunnels ready, and could start from the bottom.
 * If you're making a building, obviously you build from bottom to top, but when you're making a tunnel or a mine, it's far more logical to start from the top and build down. Two main reasons: Firstly, all the earth you dig up has to be transported out, and equipment transported in. You can theoretically manage with a single deep shaft, but it's just easier to keep the supply lines as short as possible. It's easy to do this if you have available space nearby i.e. directly above you, where you can keep all your equipment, personnel and supplies, and just keep gradually moving it down as you dig. Secondly, "digging up" is inherently dangerous. Ceilings have a habit of falling apart when you poke them with shovels or drills. No matter how hard you dig at a floor, it isn't going to fall on top of you. But, to answer OP's question: Hey it's Aperture Science! It's their MO to do everything in the most dangerous, money-wasting manner possible.

Wheatley knows about Bring Your Daughter To Work Day

 * Upon entering the room where Bring Your Daughter To Work Day was held, Wheatley remarks that it "did not end well". Did he witness whatever happened himself, or was he told the story or what? I'm wondering how he apparently knows about the event.
 * He, along with all the other AI constructs, was around when GLaDOS went berserk and it's hardly odd that he knows the story. Remember, Aperture had been creating AI's for decades -- since at least the eighties.

No gels in the new chambers

 * Is there any in-game reason that the gels were not used in the newer testing chambers?
 * Well, none is mentioned, but I could imagine it was one of the following: a) the gels were too poisonous, even for Aperture Science, b) they'd already sufficiently tested the gels by the time the newer test chambers were build, c) newer inventions made the gels redundant, d) they got bored of them.
 * The second time you open a gigantic vault door (the horizontal one that drops a lift for you) you see three large pipes from inside the room connect with pipes to the outside. The upper, newer sections were literally cut off from the gels until Chell opened the way. The gels were buried and forgotten by GLaDOS's time.
 * Though, GLaDOS did say that Wheatley's tests were her tests now, just jammed together out of different skeletons that she had kept. You used the gels quite a bit in those areas. Maybe she had initially worked her away around those pipes and did nothing with them in those chambers?
 * There's a dummied out line somewhere in the script files where GLaDOS knows about the conversion gel, at least ("Wait. I HEARD about this. We discontinued it after all the test subjects kept escaping.").

Thinking of the paradox

 * In order to use a paradox on Wheatley, GLaDOS needed to think about the paradox to use on the way up, yet she didn't short out. Maybe Caroline helped, since she was reunited with GLaDOS in Chapter 7? GLaDOS does say each word of the paradox one at a time with a pause, even the first one, like she's repeating each word after someone's saying it...
 * I always saw GLaDOS giving the paradox word by word as a way of bracing herself. Immediately after saying "FALSE" she starts muttering "don't think about it".
 * That could be a possibility - still doesn't explain much about not freaking out from the time she got the idea to the time she said the paradox aloud, since technically, she'd need to think about the paradox in order to plan out what to say if she was doing it on her own.
 * I don't think what GLaDOS thinks is true necessarily has to be true.

The bird

 * So where the hell did this bird even come from? First off, Wheatley talks about finding one shortly after you meet him again during GLaDOS's test chambers, then he uses her eggs to jam a door mechanism, then that same bird somehow ends up at the bottom of Old Aperture and flies off with PotatOS, and then she appears one last time at the end of the Peer Reviews DLC before leaving the facility for good. How did she even get in here?
 * Who says it's the same bird? They're obviously breeding in the facility.

Wheatley's 'eye'

 * All the other personality cores seen in the games have black pupils. So, why doesn't Wheatley have one? His is more white-ish.
 * The other cores may all have black pupils, but they also have different designs. It's possibly Wheatley is just the first one we've encountered so far that doesn't.

Rick the Adventure Sphere

 * What happened to Rick? Was he pulled into SPACE with Space Core and Wheatley?
 * If you watch closely, he's detached just before Wheatley is. Not sure why he didn't appear in the ending sequence, though. However if you look in the games' sound files (GCFScape will do the trick to open the gamefiles. Look for a pak01_dir.vpk) theres dialogue that sounds like he was meant to be.

GLaDOS' head

 * In one of the last scenes of single-player, you

Did Wheatley know his purpose?

 * Did Wheatley ever give any indication that he knew he was an Intelligence Dampening Sphere and was once attached to GLaDOS before she said so? This has been bugging me for a while now, because he seems to be surprised about it during that scene.
 * I don't think he did. Like you said, he seemed to be surprised by the revelation. and from what we've seen, cores connected to the main A.I are not entirely conscious (seeing how all the very Motor Mouth cores turned almost completly silent when connected), they can probably become aware of rhe situation if they want to (The Curiosity Core knowing who Chell is, Space and Rick talking while connected to Wheatley)but I WM Ged that they in sort of a sleep-like state when attached. and yes, it does mean you killed the Portal 1 cores only minutes after their first independence thoghts

Cutting the neurotoxin lines

 * One of the puzzles in the game involves using a laser to cut the neurotoxin lines. When this happen, you can see the gas leaking out before the tank implodes. Wouldn't there be enough in the tank to kill Chell or at least make her very sick when it all leaks out? I know there's Gameplay and Story Segregation but that part seems a bit odd.
 * If you do it right, she's not in the room that long; maybe the neurotoxin leaked into other chambers as well or got sucked out the pipe when Chell did.
 * Maybe the pipes just feed inactive components into the big compressor, and it doesn't actually become active until after that.