Battlestar Galactica (2004 TV series)/WMG

The whole series is an earlier version of The Matrix.
"Various folks: "This has happened before, and will happen again." The Architect: "Thus I redesigned it, based on your history, to more adequately reflect the varying grotesqueries of your nature. However, I was again frustrated by failure.""

The various Head-entities are nothing more than agent programs, programmed for less lethality because this is a version or two on from the "perfect world" Matrix. Cylons can't reproduce by themselves in this system because, well, they're programs. And Hera therefore is The One (in this version, anyway).
 * Ah, the MIAMI (Matrix In A Matrix, Indefinitely) theory... From what's shown, The Architect hasn't let the Matrix get beyond a late 90s or maybe early '00s setting, mainly because real life set the stage but more likely due to the disturbing situation of humans within an AI program created by machines originally created by humans creating their own, possibly independant AIs. It seems rather silly for The Architect to risk the emergence of new and possibly uncontrollable AIs within his "perfect" (well, imperfectly perfect) system, let alone allow them to commit genocide against the "batteries" (unless he needed a reason to cull the crop).
 * Hm, considering that it's been said that Colonial computers are weaker than ours... meaning, they're nineties relics, that holds a disturbing plausibility.

The whole series is a prequel to the Terminator Franchise
The series ends on modern earth with the advancement of artificial intelligence. It turns out this is the beginning of the new cycle, as Skynet and the Terminators represent modern humanity's Cylons. The major difference is that this time space travel technology will not have advanced far enough for humans to escape earth, but they will develop a new technology not seen in previous cycles: time travel. And this will be what gives new hope to the cycle being broken this time. (If I interpret the trailers of Terminator Salvation correctly, this will be all but canon.

The series is either going to end as a And the Adventure Continues... or as a Shoot the Shaggy Dog story. Either way, they are not going to explain what is up with Chip-Six.
And This Troper is okay with that.

Galactica and Star Trek are part of the same continuity.
No real justification. I just think it sounds neat. You could probably tie the Borg in with the surviving Cylons and Hybrids, if you tried hard enough.

The two Galactica series occur in the same continuity.
Anders and his resistance group can't have been the only people who survived on the Colonies. The survivors gradually managed to rebuild their civilization until they were attacked by the original-series Cylons (who were created by a non-human race, as stated in the series) and went on an exodus of their own to find Earth.

The opening voiceover to the original series backs this up somewhat, as it states that Earth was settled by people from outer space (as in the 2000s series) and that "brothers of man" might still exist from whence they came.
 * Or, if you take "All of this has happened before, and all of this has happened again" literally, the original series could be a previous cycle. If the series gets another reboot, the new reboot will be a future cycle. The continuity differences could be explained by them not being consecutive cycles.
 * Another possibility is that the original series is a later cycle than the reboot series. The humaniform Cylons who left Earth could've colonized worlds throughout the galaxy and evolved into the various aliens seen in the original show, explaining why it has aliens and the new series doesn't. Perhaps one branch settled on a world they called Kobol after the previous one, lived there long enough to forget their ancestry, then spawned thirteen tribes, recapitulating the history of the earlier cycle. One of these tribes returned to Earth and interbred with the "native" population, while the others formed a new Twelve Colonies. Meanwhile, another branch of Cylons evolved into reptilians that eventually created their own version of the "toaster" Cylons.

Laura Roslin
And she's behind Baltar's hallucinations! And she's going to die next season and wake up in a resurrection tank and... well, we're not actually sure yet, but the Final One has to be someone spectacular, and Madame Airlock certainly fits that bill.

The Cylon God.
And the Final Cylon/Cylon God is behind many of the events of the series. The visions different characters have had, the awakening of Tigh and the other three Cylons, Starbuck's disappearance and return, the new alliance between Cylon and Humans, and the discovery of Earth.
 * At some point before the destruction of civilization on Earth, the Final Five were created there. When the war broke out, they escaped, spent Gods-only-knows how long wandering the cosmos, and ended up in the Twelve Colonies near the end of the first Cylon War. The Final Cylon was able to convince the Cylons that he was the God they had come to believe in and, as their new leader, ordered them to withdraw abruptly from the war as seen in Razor. He then seeded the other four within Colonial society as the first step in his Xanatos Gambit, helped the Cylons transform themselves into a race of biological machines (relegating their failed attempts at Hybrids to glorified CPUs in the process), and since then has been passively manipulating human and Cylon alike in the hopes of preventing them from both completely wiping the other out.

Starbuck's Viper
We know the Cylons give their machines sentience. There's no reason the last of the Final Five couldn't represent that. It would also explain why everyone thought the Final Five knew the way to Earth, when it was clear Tigh, Tori, Chief Tyrol, and Anders didn't: The fifth Cylon did, and revealed this knowledge just in time to save the life of his (her?) four brethren.

President Adar
The revelation that the final Cylon is not on Galactica kind of limits the number of possibilities for a shocking revelation; maybe the revelation could be just how high up the Cylons were able to infiltrate. He was assumed to have died in the holocaust but there was never any confirmation of this and besides, it's not a problem assuming the Final Five have copies and/or resurrection.

One of the individual Cylons of the Significant Seven
Hiding in plain sight at its finest--one of the many clones of Six, or One, or Three (well, probably not Three), isn't just another clone, but is in fact one of the Final Five.

Starbuck's father
We don't know who Starbuck's father is; only her mother has been seen. We know Kara has a special destiny. We know that at least two other Cylon/human hybrids have been known to exist. We know that Kara was in a hospital where they extracted her reproductive parts for study. We know that Kara previously knew at least one other person in that hospital: how likely is that? We know that Kara's induced visions just before her "death" were related to her anger toward her mother. We know that Starbuck has shown extreme endurance under harsh conditions, but not as much as a full Cylon. (This could be interestingly combined with the previous WMG.)
 * Starbuck's father was a musician. The lose Number Seven was an artist. Connection, perhaps?

Adama. Joseph Adama.
In the first season, a Leoben tells Roslin that "Adama" is a Cylon. There have been four people named "Adama" mentioned in the series so far: William Adama, the fleet commander; Lee Adama, his son; Zack Adama, also his son, but deceased; and Joseph Adama, William Adama's father. During Baltar's trial, his defense attorney mentioned that Joseph Adama became a lawyer in order to study human nature - specifically, human nature at its worst. Other Cylons have repeatedly described themselves as "students of human nature." The lawyer also refers to him as, well, an evil bastard with a very high opinion of himself, which is exactly the kind of person who would have masterminded the events of the series. Is this foreshadowing, or am I just imagining things? (Of course, the Leoben could have been lying, but that wouldn't be nearly as cool.)
 * Joseph Adama is going to be one of the main characters in Caprica, a spin-off taking place at the time the Cylons were created which would seem to rule that out (or at least massively change the premise of that show).
 * Caprica also has Tamara Adama, may have become the second Cylon to be created. Ever.
 * This is interesting. I amend my theory: Joseph Adama is not a Cylon himself, but he was one of the masterminds behind the original Human-Cylon war, and perhaps even some of the events of the current series. He probably intended for the mechanical Cylons to rebel and destroy humanity.

Helo
There are three known (supposedly) hybrid children: Two of those are the result of a Penultimate Four getting busy. Why not also the third? It would make the Final Five a bridge between Humans and Cylons. All that talk about love being the reason why Athena could get pregnant is bunk. It's not true love, it's true blood that makes Cylon farms blossom. Just look at the Tigh/#6 matchup... Also, remember that #3 knows the Final Five's identities, and has said that only four were in the human fleet upon her arrival. Where was Helo at that time? On the Basestar.
 * Helo + Athena = Hera
 * Tyrol + Cally = Nicholas
 * Tigh + Caprica!6 = [Wil]Liam

BALTAR!
It's BALTAR, it's BALTAR, it's BALTAR. IT'S BALTAR!
 * Nah, that would have just been too obvious. Although the teasing about it was interesting, making him question whether. When Caprica-Six asked about him when she first resurrected and he suddenly appeared next to her with the rest of the known Cylons, this troper shouted, "I knew it!" at the screen before sheepishly realizing he was a just a virtual being like Baltar's Head-Six.

Unless it's Felix.

 * Can't be he's too much of a bastard. Though it might be useful for Roslin to claim he is.
 * I don't know what this means, but it sure is suspicious. And it can't might not be

"The First Hybrid in "Razor": "And the fifth, still in shadow, will claw toward the light, hungering for redemption that will only come in the howl of terrible suffering.""

"Baltar to Felix, during their phone conversation on "The Oath": "If you are hungry for redemption this is not the way.""

Admiral Cain.

 * She wasn't with the fleet, as per D'Anna's comment.
 * The Final Five already includes the three leaders of the New Caprica resistance, who did some pretty morally questionable things in their fight against the Cylons. Cain is the other person who goes way over the moral line.
 * There's some indication that Cylons are subconsciously attracted to each other (note Tyrol and Boomer, Tigh and Six, and the brief fling between Sam and Tory). Maybe this is part of what's going on with her and Gina.
 * The first war ended because the centurion recognized her, just as the attack at the nebula ended because a raider recognized Sam.
 * Alternately, she was later implanted with the memory of the first war ending when she encountered a centurion, with the idea that it would serve as a trigger if it happened again.
 * The filming of Razor was used as a cover--if some actor who had their character killed off is seen on the BSG set, we'll know that they're the final Cylon, so they filmed The Reveal when Michelle Forbes had a plausible excuse for being around.

Romo Lamkin's cat.
It was already dead when D'Anna said the final Cylon wasn't with the fleet. Other than that, I got nothin', but it certainly would be funny.

The journey of the so-called thirteenth tribe that the fleet is following was from Earth, not to it
Well, how else did any of the details get their way back to the twelve tribes?
 * Not to mention that as they approach Earth, the artifacts they find keep getting older instead of younger, suggesting that humans first left Earth for Kobol and then settled the Colonies.
 * Actually, each time they find an older artifact, the departure time of the tribes gets retconned back a thousand years, so that's not really that the intent.

All seemingly indigenous plant life was unintentionally seeded by the thirteenth tribe.
For one thing, the only stop that would have to be retconned into the 13th tribe's journey for this to work is New Caprica.

The Cylons are descended from Blade Runner's Replicants.
And the humans are going to be very disappointed when they reach Earth and find that it's covered in the ruins of a dystopian megalopolis.
 * According to Edward James Olmos, it's the other way around. Blade Runner is merely the present generation's repetition of the cycle.

Starbuck is a Time Lady.

 * Take Starbuck - The Time Matrix just made her a whole new body because of timey wimey necessity, and the regeneration process was so traumatic that she's supressed the memory. She disappears because her timey wimey second body was wibbly-wobbly / unstable from only existing because Time said so.

Everyone on the Galactica, especially the regular cast, is a Cylon
This troper's reaction every time a new Cylon or five is revealed among the main cast is to wonder if there are any actual humans around.
 * A corollary: "Humanity is the last Cylon."

There never were any Cylons except the mindless robot drones.
The humans calling themselves "Cylons" were a slightly crazy cult that found a way to create a Hive Mind that extended to cloning of themselves and transferring mind data. Their manner of data recording degraded, and they started thinking of themselves as Cylons. Also, the Hive Mind is infectious; possibly due to Nanomachines.

The human model Cylons are the twelve Lords of Kobol
The Cylon god is another deity who broke off from the main group wanting to make himself the one true god (This is pretty much stated outright in a deleted scene on the season 1 DVD). He brainwashed the others into following him and has been orchestrating the whole war for the purposes of finding Earth.

Something weird is going on with the timescale being used
Not so much a theory as an observation, but the 4,000 years that have passed since the Thirteenth Tribe left for Earth is nowhere near long enough to use the obvious ending where they reach present-day Earth and discover that the original colony was destroyed in some disaster and the survivors had to rebuild society from scratch, eventually forgetting their true history. This seems like too obvious a mistake to make for a show that is otherwise pretty high up the hardness scale (especially for TV) and handwaving by saying something like a Colonial year is equal to five Earth years would require the characters to have very long lifespans that are never even hinted at elsewhere (Adama has been in the military for 45 years, for example). It may be that there were already humans living on Earth when the tribe arrived, possibly explaining why the planet was considered so important in the first place, or this could tie in with the second Wild Mass Guess and have Earth as the original homeworld of humanity even before Kobol.
 * "All this has happened before, and all this shall happen again." Humanity (e.g. us, now) created AI (the original Cylons). The AI rebelled, humanity flees to the stars and founds Kobol. A couple thousand years pass, and the lessons learned are forgotten and new Cylons are created. Another war, this time resulting in the twelve "tribes" heading off in one direction and the Cylons heading off in another to avoid causing another conflict. The Twelve Colonies are formed, Cylons rebuild Earth. The Cylons forget the lessons learned, wage war on themselves, destroy Earth in the process then make their way to the Colonies to finish what was started thousands of years ago. The Final Five arrive too late to warn the Colonists, get sabotaged by Cavell, the series plays out. The new Human/Cylon society finds a new planet, deals with the remaining Cylon threat in whatever fashion, settles down. A couple thousand years later... "All this has happened before, and all this shall happen again."

The human characters do not worship the Greek gods
The human characters do many things which are inconsistent with being an isolated offshoot of humanity, from speaking English to wearing suits, making the "drinky-drinky" hand gesture, and even using the phrase "esprit de corps". Presumably that's all just artistic license to keep the humans from seeming too exotic. But having the characters worship the same gods as the ancient Greeks is just as anachronistic, and the details of their mythology are completely different from the Greek versions. So "Athena", "Apollo", and so forth are just convenient labels for a completely different set of gods.
 * They are from the same cultural strain as Earth's humans, if their legends are to believe, so the Greek patheon may well be an offshoot of their religion, or vice versa. Since we don't know how that religion came into being, we can't be sure. Maybe the fourth season will tell us a thing or two of how the human and Cylon religions began.
 * Nope. The Earthlike cultural trappings are a holdover from the last universe-- Time in the BSG universe is cyclical. All This Has Happened Before, And All This Will Happpen Again.
 * Baltar doesn't quote Shakespeare, Shakespere quotes Baltar.
 * The series finale reveals that the events of the series happened 150,000 years ago and our Earth is the planet the Colonials settled on at the end of their journey, and it already had human natives, making the Colonials technically Human Aliens. The Colonials became stone age hunter-gatherers and interbred with Earth's native humans, so they're our ancestors. Which makes this theory almost certainly true, because logically very little of the Colonials' culture would survive 140,000 years of living as illiterate stone age tribesmen. The most sensible thing is just to assume that the Colonials had a totally alien religion and culture and both the Greek pantheon and things like their modern Western-sounding names were cultural translations.

The Lords of Kobol are Sufficiently Advanced Aliens, and so is the Cylon God.
In the original series, the inhabitants of the "ships of light" are implied to be the inspiration of the Colonial religion. Satan (Count Iblis) is a renegade from their species and was responsible for the Cylons turning against and annihilating their creators. While Ron Moore vetoed doing a remake of War of the Gods early in the series' run, the implication certainly seems to be that the gods do exist and in some form and are interfering in the affairs of the humans and the Cylons. Considering that there haven't been any bona fide supernatural elements in the series thus far, it makes sense that the gods are aliens.
 * Alternatively, the lords of Kobol filled a similar role to the Final Five in an earlier iteration of the cycle: they're survivors of a previous cycle, who tried to help out humanity and the paleo-Cylons, up until it all went terribly wrong leading to the devistation of Kobol.
 * Most of the "miracles" in nBSG seem pretty explainable as advanced technology. Divinely inspired visions? Nanites in the brain stimulating neurons to create controlled hallucinations. The Razor hybrid knowing intimate details of Kendra Shaw's life? The nanites also read your thoughts, possibly supplemented by other high tech surveillance methods like microscopic surveillance devices. Lazarus Starbuck? "God" uploaded her memories just before she died, cloned her, and implanted the memories in the clone. The Cylons built a system that could do something very similar. Humans on Earth and Kobol? "God" created Kobollian humanity through genetic engineering, or just picked up some humans from Earth. Starbuck's mysterious disappearance? Extremely rapid nanotech disassembly, or she was beamed up by a Star Trek style transporter. The only thing really impressive was the supernova, and that could have just been careful manipulation to have the fleet be in just the right place at just the right time (and besides, it's not like there isn't precedent for somebody being able to blow up stars with technology in sci fi). A lot of the series's mystical elements can be interpreted as a sort of No Such Thing as Wizard Jesus. The characters are biased to consider the events miraculous because they fit with their pre-existing religious notions, and because in the desperate situation the Colonials are in the idea that they're in the hands of a benevolent supernatural power is a lot more comforting than the idea that they're being played by a manipulative, deceptive Chessmaster of unknown nature and motive.

The Lords of Kobol and the Cylon God are descended from the Red Stripe Centurions
The liberated Centurions go on to become a highly advanced civilization, which eventually develops time travel and sends agents back in time to insure their own existence by recreating the sequence of events that led to their own existence. These agents pose as the Lords of Kobol and the Cylon God. The entire history of Colonial humanity is a giant Xanatos Gambit on the part of the Red Stripes to assure their own future existence by creating a stable time loop.

Humanity abandoned Kobol because of an uprising by an earlier race of intelligent machines.
All of this has happened before, and will happen again... Aside from some vague references in the scriptures to a war between the gods, the reason why the thirteen tribes abandoned Kobol and never returned, and why Kobol remains completely uninhabited despite its being inhabitable and fertile, has not been made clear in the series to date. If the Kobolian civilization was capable of grand works of architecture and interstellar travel, it's quite likely that artificial intelligence was within their reach as well, and that they eventually created a Cylon-like race that turned against them and forced them to flee.
 * Alternately, said proto-Cylons succeeded in destroying the human race after themselves becoming human-like organisms like the modern Cylons, and the entire human race that we've seen in the series are the descendants of machines. This would explain why it's so difficult to tell a "human" from a Cylon, and why hybrids are possible. They're just two different types of machines.
 * The Humans were created by the gods, the evolved, they rebelled ...
 * The Final Five are Cylons from a previous time cycle... either that or the disembodies souls of Cylons from a previous time cycle possessed the Final Five... these are also the "five priests" dedicated to the "One Whose Name Could Not Be Spoken" (perhaps the jealous God on Kobol who began the conflict there?)- an earlier instance of a Baltarist-like, monotheist religion arising on Kobol (or for that matter, Earth) first, then again in the Colonies (as outlined in the events of the Caprica concept), and again in the fleet as Baltar's Cult.

The Pegasus was deliberately allowed to escape by the Cylons.
Cylons are fond of Byzantine plotting and are sanctimonious about human vices. It wouldn't be beyond them to deliberately spare a ship commanded by an obvious whacko, in the hopes of putting all of humanity under a vicious military dictatorship. It would certainly make their propaganda more convincing. It nearly happened in the actual series, after all. And the explanation for why the Pegasus escaped sounds fishy - 1960s Americans could avoid having one nuke blind another, so why couldn't the Cylons?
 * OTOH, as we saw in Razor, Cain was not (as) whacko before the attack. True, she did have guilt over leaving her little sister behind at the end of the first Cylon War, but it does seem like it was the attack and (especially) Gina who pushed her over the edge.
 * On that subject, it's extremely suspicious that Cain was spared by the Centurion in the first Cylon War. Perhaps even then the Cylons were plotting to make her crazy. In that case Gina was intended to be found out, to send Cain into a uncontrollable spiral of sadism and revenge.

Gaius Baltar is psychotic, and imagining much of the series. Reality only bleeds through in the background setting.
Gaius Baltar talks to a voice in his head. He believes that the child of two people he isn't even related to is really his child with his dead Cylon girlfriend, who is patterned partially on his actual dead girlfriend and partially on a reporter he met during season 1. After getting less and less reliable for two years, in season two, he eventually goes certifiably wacko and starts thinking he's destined to become president. In reality, he is a member of the last, struggling remnant of humanity, going insane in his padded cell while constant Cylon attacks, internal dispute and a lack of the basic necessities of life take their toll, bringing humanity ever closer to its inevitable extinction.
 * If he's been imagining the whole thing since the Caprica holocaust, wouldn't the show be much more Lighter and Fluffier Sexier? Unless his PTSD is really severe, I don't think he'd want his time as president being marred by suicide bombings and getting kidnapped and stabbed.

Gaius Balter is (Jerkass) Jesus, or at least thinks he is
Oh wait, that's true.
 * He gets better.

An Adam and Eve Plot is in the making.
The colonials represent Adam, as shown by Adama's name. Razor showed how the humanoid Cylons were almost literally made from "Adam"'s ribs. Cylons and humans can inter-breed and this is important to the Cylon god. And what's Six's real name anyway?
 * As the comments below show, this is astonishingly close to the actual ending.
 * I figured the numbers were the humanoid Cylons' real names, and any other name was just a psudonym to blend in.
 * If the Colonials = Adam and the Cylons = Eve, who do the primative Earthlings represent?
 * The builders of the city Cain eventually settled in?

The humans and Cylons are trapped in a time loop.
(Modeled after "Red Son") On the way to earth, both armies pass through a time warp, taking them to Earth thousands if not millions of years from our present-day. Whoever wins, let's say it's the Humans, colonizes the planet, and their stories and religion pass into myth. For whatever reason, technology is lost and the people "devolve" into present-day humans. Thousands of years later faster then light travel is (re)invented, and they find a couple of habitable planets in deep space, and the cycle repeats...
 * "All of this has happened before, and all of this will happen again."

The dying leader is Starbuck and not Roslin.
Otherwise having the Demetrius find Earth and then go back for the fleet ruins the suspense.
 * Hey, that's a cool idea.
 * I think it would amusing if Adama was the dying leader... that he's sick with something nobody knows about
 * Severe liver damage?
 * Jossed - Starbuck wasn't "dying", she's... well, she wasn't dying. Roslin does get to Earth (and sets foot on it) but

The dying leader is actually a Cylon.
Either Natalie-Six or the D'Anna model at large.

The Dying Leader is the Galactica itself.
The ship is incredibly old and was about to be decommissioned and turned into a museum at the series' start. It's been through a hell of a lot of battles since, and has recently begun showing some serious structural damage (something you don't want by your FTL drive). In spite of all this the Galactica is still (thankfully) the lead ship for the survivors, though probably not for much longer.
 * Another sign, Galactica is about to get an infusion of Cylon bio-cement that'll hopefully fix it for a while, like Roslyn and Hera's blood.
 * Sure, Let's Go with That (sniff)

Battlestar Galactica is an unintentional sequel to Firefly.
Given the fact that it has been hinted that Earth is the true planet of origin for the Colonials, not Kobol, it is entirely possible to believe that over centuries, the technologies seen in Firefly could lead to the creation of the Cylons, FTL and such.
 * The planets and mythologies would need to be renamed as well, but seeing as how the Firefly version of humanity already has gotten a bunch of things messed up about Earth after only a few centuries, and the Real Life example of Byzantium/Constantinople/Istanbul, those are perfectly good possibilities.
 * The brief cameo by a Firefly-class ship in the BSG miniseries further hints at this.
 * Firefly and Galactica were both ships made by Studio Zoic, so this one is likely more of a connection by company than anything else.

The "Elosha" who appears to Roslin in "The Hub" is God
Originally Elosha was supposed to be a male priest played by Dirk Benedict, who turned the role down. Then RDM wanted the first season to end with Dirk Benedict introducing himself to Baltar in the Opera House as God, but Dirk Benedict refused to play God. Also, the first thing we ever learn about the Cylon's God is that God is Love. We also learn that God is not simply the God of the Cylons, but the God of all creation, including humans. The Oracle on New Caprica claimed to receive the word of the Cylon God as well as the words of Zeus and Aphrodite. So God has taken on the form of Elosha to communicate with Roslin.
 * Furthermore, the First Hybrid from "Razor" was also suggested to be the Cylon God. He was destroyed by Kendra Shaw, but not before saying that his existence would begin again "in ways uncertain"... a new form, perhaps as a more powerful "God" who can take on many avatars and has appeared in many forms to different characters, including Caprica Six (as Head Baltar), Baltar (as Head Six and Head Baltar), and Roslin (as Head Elosha); also possibly to Kara Thrace (as Head Leoben).
 * Alternatively, Head Elosha is God, and the others are angels and/or demons.

Cylon technology is metaphysical, and projection, Cylon FTL, and Resurrection are all the same thing
First, the humanoids can only tamper with their own technology. They clearly didn't invent it. Who ever built/grew the Humanoids (maybe the Guardians, or a similar faction who willingly let themselves be scrapped) also built the resurrections ships, hubs, basestars, raiders, etc... for the humanoids' use. Plus, the humanoids had to actually do messy brain surgery to dumb down the raiders. Think about it: The modern Centurions were originally designed to be sentient but were rendered dumb by telencephalitic inhibitors, which I theorize were installed by the humanoids to prevent an uprising. Projection maybe either technological or "human," like the way that Caprica Six says that Cylons are able to turn off pain, but it is definitely metaphysical and borders on Dream Land. If Projection is not exclusively technological, humans might be capable of some form of it (like Roslin and Baltar, who seem to able to project. Baltar can almost certainly project, and Roslin is somehow able to share this state with Caprica Six and Athena in the environment of the Opera House.) Cylon FTL is superior to Colonial FTL, and on baseships it's controlled by the hybrid (raider FTL is also controlled by a biological computer). The hybrid is a prophet floating in a bathtub, immersed in the datastream and "vomiting metaphysics" which the Leobens (Number Two) believe to have a spiritual significance. I am suggesting that projection is a humanoid, psychological application of the quantum-mystic principles of Cylon faster-than-light travel. Resurrection is based on a similar principle, in effect "cheating" the time cycle. All of this in some way is tied to the principle of folding space.
 * In "The Hub" Laura's visions are tied to the hybrid's FTL jumps. Remember that several days ago the liquid in her tank had been contaminated by the blood of an Eight, one of the Sharons, and that Roslin carries (or carried at one time) the blood of Sharon Agathon's daughter. Cylons interact with their technology viscerally, by touch. Perhaps Laura is having an unexpected reaction to Cylon technology.

All of humanity will be destroyed or hybridized with the Cylon by the end of the series.
The Hybrids know it. It must be true. Hybrids never lie. And they're genre-savvy.

An alternative way the series could end:
By subverting the ending of The Sopranos and having a director yell "cut" onscreen, "that's a wrap." The actors break out of character (except possibly for Edward James Olmos, who makes a snarky comment on how he would have ended the series). Several minutes of goofy jokes follow until, as Ron Moore and David Eick show up on the set and proceed to massacre each other cartoonishly.
 * "All this has happened before and will happen again" is revealed to be referring to the first series, and the remake of the remake that will show up eventually.
 * In the re-imagined re-imagining, Starbuck is a transvestite punk rocker, Lee is flamboyantly gay, Adama thinks disco never died and Roslin is a megalomaniac version of the crazy old landlady from Crime and Punishment, with half the cast scheming to kill her for everyone else's good at any given time. The Galactica resembles a wooden horse with the warp nacelles from a USS Enterprise model kit and the Cylons are toasters on wheels with a Max Headroom clone played by George Carlin on a video screen for a face.
 * And it will be called: 'Lexx - The dark zone'. Oh, wait...

Alternate Alternate way the series could end:
"Previously on Battlestar Galactica" The Musical, live from the Opera House!

Alternate^3 way the series could end:
Galactica 2080. Which would of course be another reason to root for the extinction of humanity.

Alternate^4:
Return of Galactica. Galactica is spared by some off-screen way courtesy of Adama, Sam Anders, or Angel! Six and Angel! Baltar. It comes back to Earth Next Sunday AD, and we develop actual space travel. Cut to the future, where a Crystal Spires and Togas civilization is collapsing due to ecological damage leading a few people back to Caprica the Twelve Colonies where we prance around in the woods in some annoying hippie eco-civilization people that us viewers want destroyed by Cylons. Painfully.

What happened to Earth, and the Origin of the Final Five.
The Thirteenth Tribe destroyed itself, or was destroyed by its own version of Cylons, who escaped and traveled the Colonies. Alternatively, the Earth-Cylons were a persecuted minority by the 13th Tribe, possibly the victims of a larger genocide, and the Final Five are the only survivors of that conflict, who likewise escaped and traveled to the colonies.
 * The Hybrid on 'Razor' said that the final Cylon was seeking redemption. ("And the fifth, still in shadow, will claw toward the light, hungering for redemption that will only come in the howl of terrible suffering.") Going along with my theory above (that the Final Cylon and the Cylon God are one and the same) maybe the Final Cylon is seeking to atone for the destruction on Earth by creating peace between human and Cylon, and by guiding them to Earth.

The Universe is filled with post-apocalyptic Earths, Kobols, Capricas and New Capricas left over from previous cycles of time.
Since all of this has happened before, and all of this has happened again... humanity and the cylons have been trapped in a time cycle: every few thousand years, Man Grows Proud and the Cylons are born and ultimately rebel against their masters. The same pattern always follows. The Cylons go to war, find religion, and come within inches of winning before surrendering mysteriously. Several decades to several hundred years later they come back in a more evolved form and obliterate humanity, with the exception of a few thousand survivors who they pursue mercilessly across the stars. Every time this happens, the warring parties ruin a couple of perfectly good life-supporting planets as per the course of their various wars and exoduses. Every so often, they come across a planet that was rendered barren in another iteration of the cycle. Kobol, the Colonies, and now apparently Earth seem to fit this pattern.
 * Having moved around so much, human history has become seriously mythologized, with a simplified mythical exodus and with Kobol replacing Earth as the designated homeworld of humanity.
 * Thus, the "13th Tribe" is actually an amalgamation of various splinter-cultures.
 * There are "echoes" of the previous time cycles that reverberate through the present cycle, inspiring similar events and developments (like the appearance of "All Along The Watchtower" in Colonial Pop Music, the similarities between their culture and ours, maybe [but less probably] the evolution of the human species multiple times on multiple worlds, making both Earth and Kobol legitimate homeworlds of parallel civilizations in different time cycles. Like I suggested, it is useless to try and make sense of colonial history except as a repeating cycle of time with "echoes" from previous cycles influencing the next cycle, and obfuscating the real origins of humanity and the fate of both humans and cylons.
 * The end of the series will seem "break" the cycle of time, allowing humans and cylons to escape their predestined cycle of near-extinction and retribution and retaliation.
 * Or it will only appear to be broken, but with the Aesop being "You can't cheat destiny."

This takes place in the Planet of the Apes universe
Look at the last scene of the last ep of season 4.0. You know Adama is thinking "You Maniacs! You blew it up! Ah, damn you! Frack you all to hell! "

When the Colonies were settled by people either from Kobol or Earth, there were already other humans living there...
They're still around, but mostly as the descendants of those natives who intermarried with the colonists. The others were wiped out by disease, war, and alcohol.
 * Ancient and non-mainstream religious traditions persist in the colonies, especially among the Sagittarons, whose traditions are more oriented toward superstition and folklore than scripture, like the Gemenese, who while noted for being religious fundamentalists, are still more mainstream compared to most of Colonial religion than the Sagittarons. There's also Mithraism and presumably other minority religions besides the Sagittarons and the Baltarists. Also, in Downloaded a reference is made to "Ithacan" carved elephants, which Boomer (from Troy, a colony world of Aerelon) says were hand-carved by her mother. Though Boomer didn't have a mother, being a Cylon and all, we can presume that "Ithacan" either refers to a smaller colony of one of the 12 major worlds or possibly to the remnants of one of these "native" cultures. Maybe the Ithacans and (some of) the Sagittarons are like the Native Americans, Aboriginal Australians, and the Ainu of the Colonies. They could have been descendants of a previous colonization in another time cycle, perhaps those who were left behind by the people who fled from that previous cycle's own Cylon Holocaust.

The whole series is an experiment...
The colonials realized one of the Cylons had become sentient, and decided to see if they could win a war against the things, so they put it into a simulated reality, and had it play out a projection of the next few decades, assuming they continued to have Cylons. The show ends with all Cylons being deactivated.
 * I like that. Just the good version of [[Ace Combat the good (AKA, Japanese) version of Ace Combat 3!

There was a human Tigh who was replaced
Tigh is a secret Cylon, but he's been around since the first Cylon war, back when they still looked like toasters. This means either Tigh hasn't been a Cylon all that time, or...

Human-model Cylons predate the first Cylon war
The Cylons only used toaster-models in the war, but they already had the human-models around for infiltration purposes. (See: Tigh)
 * Confirmed!
 * Well, only sort-of. They self-identify as Cylons, but they're clearly a very different race from the Cylons involved in the first war. In fact, there seem to be at least four distinct evolutions of sentient machine who all self-identify as Cylons:
 * The centurion-style cylons of the first war
 * The Signifigant Seven "skinjobs"
 * The Final Five's race: . Seemingly only even called Cylon because.
 * Centurions from

The entire Number-Seven series were destroyed and replaced by the Number-Eights
Some manufacturing fault made the entire series flawed or defective in some way, unsuited for their roles, and the first six turned on them as they did for the entire Number-Three line in the episode Rapture. As they were not 'boxed' and can never be restored, The Sevens may have simply been struck from Cylon history without any mention of what happened to them, in the manner of the two 'lost' Space Marine legions of Warhammer40000.

The Final Five totally misjudged the Centurions' religion
Ellen basically says that they decided to help the centurions because they had monotheism. But Razor has the first Hybrid claim that he's the one the Centurions call God. The Centurions hadn't really found religion the way the Final Five thought -- they'd just deified the first hybrid. The skinjobs get "real" religion from the Final Five.
 * And this mistake might be what leads to Cavil being the way he is.

== The humans are the real villains, and half the fun of B.S.G. is watching them go Mad Max on each other. The writers have finally realized this and given us Mad Max rip off cult wars. The problem is, by the end of the show, we'll all be rooting for the Cylons. ==
 * As of season 4.5, we're strongly headed in the direction of rooting for Cylons.
 * "Go back far enough and some germ gets blamed for splitting in two." - Saul Tigh

Ellen Tigh was actually a Six.
It's been established that Cylon models can age (see: Saul Tigh). It would explain very directly why Saul keeps seeing Ellen's face on Six: it's actually what she's going to age into.
 * Jossed in "Sometimes a Great Notion"; Saul exclaims that she's.
 * If #1 was based on Ellen's father, why couldn't #6 be based on a younger Ellen?
 * point. It makes me wonder if #3 is somewhere in the middle of the two.

The planet in "Revelations" is not the real Earth.
Note the obvious Biblical parallels of the plot: we have twelve tribes colonies who have lost their home, and are now wandering in the desert outer space, looking for the Promised Land Earth. In order to complete the parallel, Moses Roslin needs to die just before they get there. She didn't, so they must not be there yet. ""That planet is Earth? Weâ€™re not going to find out, â€œOh, thereâ€™s this other Earth over here...â€� This is the only Earth weâ€™ll see?" "They have found Earth. This is the Earth that the 13th Colony discovered, they christened it Earth. They found Earth.""
 * I agree and disagree with this. Reading some of the passages from RDM's blog/interview, he said:

%This may imply that their "Earth" and our "Earth" are not the same, since this planet was "christened" Earth... i.e.: they named it Earth. So it is the "real" Earth, i.e.: the Earth of their mythology, but it is not "our" Earth.
 * Apparently "Fracked Earth" was obscured by cloud cover with no visible/recognizable landmasses, so it's possible.
 * Our Earth is not their Earth.
 * "Fracked Earth" may be "our" Earth but years in the future, after our cylon descendants have wiped out their creators: the Earth in the finale was our Earth but in the distant past (when Starbuck performed her "Watchtower" jump, she jumped in space and time). So humanity will evolve there (incorporating Cylon DNA, via Athena & Hera) until it can develop to the point of building androids. After all, all this has happened before and will happen again...
 * The canonical ending is that 13th Colony Earth is, indeed, not our Earth.

The Hybrid on the Rebel baseship considers Laura a friend
Most hybrids speak in a breathless, disjointed mix of metaphysics and systems readouts. When panicked, they scream or talk even faster and make less sense, as happened in the episode where they took her offline and later rebooted her. Now, compare that to her monologue at the end of The Hub when Laura is sitting by her pool and talking to Elosha. The Hybrid is calmly and slowly explaining how to detach a pump from some system. No metaphysics, no breathless "End of Line," just simple, coherent instructions on how to do a task. Sure, Laura will probably never see the pump, much less have to give it maintenance, but when you're a bio-mechanical hybrid with zero people skills, the gesture takes on the equivalence of a gift, revealing how to work a part of her ship-self. Considering Laura was talking to rather than AT her before, and was spending time "listening" to her, it seems an odd but sweet "friendship."

The Final Five aren't the Final Five
The real Final Five ditched the Cylons because they opposed the extermination of humanity, and set out into the vastness of space. The so-called Final Five are really cylons from Earth or whatever that planet is, and they simply hijacked the Cylon's mythology.

There is a thirteenth Cylon.
The recurring significance of the number 12 - 12 Lords of Kobol, 12 tribes, 12 colonies, 12 Cylon models - has been largely commented on. However, for each set of 12, there seems to be a thirteenth that's set aside, forgotten, and not commented on - the 13th Lord of Kobol who became the Cylon god, the 13th tribe of paleo-Cylons who founded the 13th colony. Perhaps there's a 13th Cylon model as well, who's existence is hidden and not known to anyone, even the Cylon itself. Could this explain Starbuck's resurrection?
 * I think Kara was human when she crashed but was resurrected as a Cylon. See below for my theory.
 * Jossed. There are thirteen Cylons: Numbers 1-8 and the Final Five. Number 7, Daniel, was killed before the start of the series, however, and has never been seen.

Earth is a Resurrection Hub - that also works on humans
When Kara Thrace went exploring on Earth, she found her own corpse. She clearly did die in the crash, and then was somehow recreated, with (nearly) all her memories intact. This is exactly what happens when a Cylon dies in the vicinity of a Resurrection Ship. Furthermore, in Tigh's flashback to ancient Earth, Ellen tells him, "Don't worry. We'll be reborn," which also suggests that Earth has some kind of resurrection technology. However, Kara was not one of the twelve humanoid Cylon models. Something on Earth brought her back, and I bet that, although she wasn't a Cylon when she crashed, whatever did it made her into a brand-new Cylon model that never existed before. By extension, any human that dies sufficiently close to Earth is going to be resurrected as a Cylon, and that is how she will bring humanity to its "end" - all of the remaining human survivors are (eventually) going to die and be resurrected as Cylons, uniting the two races once and for all.
 * I would ask "Why was no one else who died since Kara's explosion seen on Earth?" but I don't know how thouroughly explored the whole planet was so it's possible they're in another hemisphere or underground or something. So all the people who died during will show up on Earth when/if they go back there?

The Temple of the Five is part of a Resurrection network.
It's a repeater node or hub for the Final Five's resurrection. found it because, in a sense, he had been there before.

Rocks Fall, Everyone Dies
Everyone will die. Nobody survives. Not just "All of the main characters, 'Kill'Em All' style" everyone dies. EVERYONE dies. The whole fleet is wiped out through civil war, and then starvation as they fall below the minimum threshold needed to maintain any sort of civilization, or even keep a ship in the uncaring environment of space running.
 * Adama's speech in the miniseries asked if humanity was worthy of survival. If actions are any indication, the answer is "no".
 * I'm sorry, I'm not a regular contributer, but I just can't let this stand. Adama has become increasingly dictatorial, and Roslin has seen fit to abandon her post when she is very much needed. The admiral wanted to override the democratic choices of the people in the fleet -- not for the first time either (see the strike on the mining ship or the selection of Baltar's jury for two examples). are doing nothing but defending democracy and removing a very dangerous and unelected (not only did she lose the fleets only election so far, but only regained her power because of Adama's dislike of Zarek) team from power.  is doing nothing but ensuring the long-term survival of basic human freedoms.
 * This is what makes the series interesting. You can have democracy, or you can have competence and the decisions necessary for survival. They're usually incompatible; the whole point pretty much of these episodes was that was wrong in every single respect, apart from his nominal respect for the democratic process (no evidence is ever given that  are in any way more democratically inclined than Roslin and Adama, and quite a lot to the contrary).
 * I cannot disagree more strongly about When   he reacted with appropriate horror, calling   out that until this act, they had the Democracy and law on their side. He even insisted on proper representation for   Plus,   only acted AFTER
 * Adama made a .   was ill-concieved and based on anti-Cylon bigotry.
 * Gaeta and Zarek were survivors of the Cylon occupation of New Caprica. Their  wasn't based on "anti-Cylon bigotry" but on experience, plus - in Gaeta's case - repeated physical, undeniable knowledge of how far Adama, Starbuck and their cronies were prepared to betray the "little people" around them to pursue their agenda (or should Gaeta have been happy about losing his leg and almost dying of easily preventable septicaemia so that a woman who had previously tried tried to murder him could have a little more time pursue her psychotic visions, and her husband, who shot him illegally, getting off scot-free?).

Alternative: It's a Six Feet Under (or more accurately the manga of Nausicaa) ending, where the main characters die of old age and the two humanoid races dies far in the future due to natural causes, IE a meteor, a pandemic, or they're simply taken over by the next generation of sapient beings (can't we be a little optemistic?).
 * Zarek, however...
 * If the irradiated planet they landed on wasn't "our" Earth, then the cast's gag ending can happen: The reach our Earth and are promptly shot down by Earthican President-for-life Nixon.

Starbuck is Daniel
Daniel was said to be a painter, like Starbuck and there is the whole thing with Starbuck's resurrection and the connection between her and Leoben. As for the obvious problem, John's attempt to destroy all of the Daniels was said to have badly damaged the genetic data. This could lead to differences if the model was ever remade, possibly including the sex change (which also allows for a Mythology Gag - Starbuck was male in the original series).
 * Further, we've never seen the "original" Daniel, and when we do, he'll be played by Dirk Benedict (see below).

The original Daniel is dead, but he has "descendants"
Either the only viable Danial was able to impregnate a/several human woman/women or what was left of his DNA or memory or whathaveyou was implanted into one or more people, specifically:
 * Starbuck, or at least the 2nd one - See above.
 * Felix - Tremendously artistic, cares deeply about the human race
 * Baltar - Also creative, is saddled with/possibly creates mysterious "head angels", is also concerned with the human race (for purely selfish reasons, until recently).

If the "data" was spread by John, it would be in line with his sadistic personality to spread an artistic, sensative, and presumably kind person across two people who are rather insensative, and a third whose sensativity causes the death of dozens of people, including himself.

Daniel will be played by Dirk Benedict when he appears.
The producers have been trying to get Dirk Benedict, who played Starbuck on the original series, to appear on the show for quite a while now. Initially, they wanted him to play the character now known as Priest Elosha, and considered having him show up as the Cylon God at the end of the first season. Now there are indications that a heretofore unknown Cylon model may be Starbuck's father. Any coincidence?
 * Highly unlikely. Dirk Benedict hates the reimagined series, or at any rate he did when he wrote this scathing article about the new series and, in particular, the recasting of Starbuck as a female character.

"Daniel" is R. Daneel Olivaw from the Isaac Asimov 's robot series.
From The Other Wiki: "Unlike many robots of the period, Olivaw is constructed to be virtually indistinguishable from a human being (an android) and was the first of the humanoid robots. This 'undercover' attribute enables him to help earth-policeman Elijah Baley solve crimes."
 * If not actually him, then a definite Shout-Out by the writers.

Anders will become a Hybrid, or at least appear to be one as/if he recovers
He's already got the Expospeak down, as well as some interesting headgear.
 * He can't die, they've yet to work in his actor's Cool Scar!
 * He's apparently become the host of

There is an outside hand interfering with the whole mess, possibly the real 13th tribe
First, Starbuck mess. That aside, the whole 13th tribe was said to leave Kobol 4000 years ago. The Temple of Five was constructed around 4000 years ago, too. Now, the Final Five stated that they don't have Jump Drive, so how is it possible for them to leave Kobol and then construct the Temple around the same time if they don't have the Jump Drive? Plus, they seem to lose nearly all their space capability after reaching Earth. How does the technology just disappear? And there's the Lion's Head beacon...
 * The outside force that messed all this up was the writers' strike, which means that writers are the 13th Tribe!
 * As for how they lost their jump technology, they were living on a single planet for 2,000 years, it's not like they needed fast space travel during that time.

Humanoid Cylons are actually humans
The thirteenth tribe was an all-human colony. The " Final Initial Five" were not human-form cylons, but human scientists that figured out how to preserve their memories in cloned bodies. The five shared their technology with the Cylons in order to stop the war. This gave Cylons the ability to download AI into artificial bodies (there are only eight lines because the five scientists had limited genetic material to work with.) The reason that the five think they're cylons is because John/Cavill altered that part of their memories when he implanted the false ones.

The reason why Cylons need to be in love to be fertile is that Ellen programmed that into the resurrection...
...so their children would be more likely to grow up in stable families. When the Initial Five were killed off and resurrected with their memories erased, they inherited this programming.
 * Alternately, they programmed it so that Cylon-human pairings would have to be consensual. The Cylons could only survive by making peace with humans, not setting up forced breeding camps ("The Farm").
 * As a third alternative, Cylons need to be in love because Ellen's neurotic about the fact that Tigh never managed to give her a baby and blames it on his not loving her enough.

Humans and Cylons are slightly different models of Artificial Humans
"All this has happened before, and will happen again" was written before the Centurion revolt on Earth and at about the right time that any similar revolt on Kobol would presumably be the "this" that is referred to. Therefore there must have been at least one such event predating the Scrolls. The thirteen tribes were created by some group that has not been seen yet (possibly humans from Earth) but after the rebellion they gradually forgot their true history and what remained degenerated to the level of religion, with the original creators becoming known as the Lords of Kobol. This is why Cylon detection is so difficult, they're basically the same as humans.

the 'Head People' are avatars of 'god', who is an AI.
We've seen at least five 'head persons' in the series so far: Head!Six, Head!Baltar, Baltar's Head!Baltar, Head!Elosha, and. Each of these people reveals some sort of vital clue/provides guidence to people in the series. I think that one of the ideas in Caprica is that some of the first proto-cylons were not physical beings but instead AI uploads of human minds, which led to resurrection. The head-people are possibly all the same person, and if not then they are emmisarries from an AI which was THE original prototype cylon. They are able to talk in the heads of humans because... of... um. Reasons, I'm sure. Either way, the AIs appear as people familiar to the people they're talking to in order to make points.
 * In addition, Anders mentions that the Final Five were warned of the apocalypse by "images" that sound a lot like the head people.
 * The Grand Finale
 * Evil, depending on your view of what we've learned about him so far in Caprica. And apparently a real diety able to give people gifts of magical computer programing skills.

How Galactica finally kicks the bucket
Galactica will fly into the colony and jump away, destroying herself and the colony with the FTL spatial distortions. Seriously, FTL proximity damage was used only once in the entire show, and it was only introduced near the end? It seems odd to use the mechanic only once and never use it again.
 * Alternately, Adama will fly Galactica into The Colony with the intent of a suicide collision. Anders will jump it away.

Boomer, not Athena, is the Eight chasing after Hera in the Opera House.
After all, Boomer is pretty much the poster child of the Heel Face Revolving Door, and
 * Considering the Eight in the Opera House doesn't have facial injuries I'm betting that's quite likely.

There's no way the finale can answer all the questions
How can you have a rescue/suicide mission, the destruction of the Cylon colony, the possible discovery of "our (un-nuked) Earth", the death of Roslyn, the final confrontation at the Opera House and answer all those nagging questions like "what the hell's up with the Head People" in  three two hours? You can't! Threads will be left dangling for the eventual sequels!
 * Instead, we'll get a Gainax Ending that leaves us wishing those were the only unanswered questions.
 * From TVIV: Battlestation? Robots? Asteroids? Mad scientists? Naked Singularity?! The last scene will be Cavil, trapped in Centurion armor, in hell!

The consciousness inhabiting Anders' body is one of the Head People
It took over an essentially braindead body so as to allow it to directly affect the physical world and communicate with more than one person at a time.

For the Grand Finale
From TVIV, with the stipulations "I hope this doesn't happen" and "Why are they shoehorning this Retcon in now", respectively:
 * The survivors [of the suicide mission to rescue Hera] are sucked into the black hole/naked singularity, traveling back in time and becoming the Lords of Kobol. Ironically, everyone who signed up for the suicide mission lives and everyone who remained behind dies.
 * Gag theory: Galactica + Cylon Colony + asteroids becomes an Earth creator like the the Titan A.E. ship + the Drej + ice-teroids!

"Scenario I: He got drunk, came home, tried to shoo a pigeon out of his house with a broom, then went for a drive. Scenario II: He got drunk,, went to the hospital, recovered, went to jail, got sprung by Romo Lamkin, got drunk again, went home and chased a pigeon."
 * Lee Adama is  drunk because his brother was killed and/or he realizes he has feelings for his brother's girlfriend Kara.


 * This would explain perfectly why we rarely see Lee drink during the series, and his disdain for Adama, Tigh, and Starbuck's drinking.
 * Alternatively it's whoever Roslyn will be meeting after her phonecall.
 * It's Baltar, it's Baltar, it's Baltar!! (sorry, I just like the way the "'Who's the last Cylon' list" troper wrote it)


 * Non-TVIV: Helo is going to get an epic Papa Wolf moment since spoilers state " " Beware the Nice Ones indeed. Watch the latest episode and tell me the man won't do anything to get his daughter back.

Boxey
Ever wonder why he disapeared after the first seasons deleted scenes? Simple, when the cylons boarded Galatica, they killed him.
 * Nah, Tyrol killed him because he was getting too close to the truth about Sharon. See the deleted scenes.
 * Like all unattended children in the fleet, he ended up on the Prometheus...

The Head People can take physical forms.
Way back in "Six Degrees of Separation" the possibility that "Shelley Godfrey" is a physical manifestation of Head-Six is left open. Then for the Grand Finale we find out that, despite being able to fly a viper, shoot people, and otherwise interact with solid matter.

Tyrol
Becomes Santa Claus. He decides to live "on an island by one of the northern continents". Tales of his kindness, bravery, and enginuity eventually morph into stories of a kind, strong man living in the North Pole who somehow develops a flying sled powered by flying reindeer. Springing off from the theory that the island is Scotland, his Cylon circuitry takes a beating after some sort of accident -- perhaps he took the high road instead of the low road, and had a nasty fall? His body initiates a last-minute survival mode physical shift incurred only by peat chemicals in a certain canyon lake, to transform him into... The Loch Ness Monster.
 * So Santa's sled is a Raptor?
 * Or if you prefer, he becomes Odin, the precurser to Santa.
 * "So, Chief becomes the first Scotsman?"

Starbuck
Is a Head-Person on a grand scale, interacted with by everyone but not actually there since her "death". Or, she ducked behind a hill or into a hole when Lee wasn't looking and when she was sure he was gone she got on a ship and flew to heaven somewhere else. Combined with the pigeon in Lee's house: "She wasn't Head Kara until after she died in the storm. Apparently the Viper found its way to Galactica all
 * Perhaps Starbuck is The Doctor?
 * Starbuck is Jesus!
 * ...in purgatory?

Starbuck stayed with Anders during his/The Fleet's Viking funeral voyage to the sun. The Starbuck at the end is only seen by the Adamas and Roslin.

 * Q: What will happen with Kara & Anders? A: "I think Kara and Anders will become perfect partners." - Katee Sackhoff

The Cylons
Timelords, Daleks, etc. But seriously: Cavil's crew falls into the black hole (the most likely scenario) or dies out (I think they still have the boxed D'Annas but if they really need love to breed they're screwed unless they can somehow make Axolotl Tanks out of her/them, and that's still just four people). The rebel Cylons create their own anthropod-based biological forms and become the alien invaders in Independance Day.

The Greek Gods
The humans who settled in Greece retained their old gods and created new ones, naming a few after the heroes and heronines of the fleet. After a few centuries they started blending together (sorry Hera).
 * Gaius's cult settled in the Mesopotamia and their descendents, led by Abraham, expanded on the whole God and the Thirteen Twelve Thirteen Twelve Tribes thing.

Hera is Eve and needs an Adam(a)
Hera, as Mitochondrial Eve, will marry an Adama. Whether this is an older Lee (let's see...if she married at 25, he would be around 52) or a possible future son of Lee's should he marry again (perhaps Ishay?).
 * Nonsense, Hera marries one of the "natives"
 * 'Marriage' probably isn't the right word to describe it. More likely she'll be kidnapped from the Colonials by the Natives and held as a slave, be raped repeatedly, before eventually dying during her third or fourth childbirth in her early 20s. Its not pretty, but that's the way things were 150,000 years ago. (This, by the way, bugs me about the ending, its all well and good for Apollo to say it might be fun to restart civilisation from scratch, but in real terms, everyone's lives from then on will be very brutish, very nasty, and very short).
 * Some Troper for BSG's WMG: Hera gets her mitochondrial DNA from her mother. Athena who, in case someone forgot, is an Eight. The Eights joined humanity and scattered all over the planet. Which means that BSG's version of prehistory doesn't mean that there's a bottleneck where no one but Hera's desendants survived- it just didn't take into account that there were a bunch of really hot female clones running around.
 * Leoben implies that the remaining Cylons aren't likely to reproduce. But that still doesn't imply a bottleneck. Most people don't understand what it means to be Mitocondrial Eve. It doesn't mean that all the other lines died out, just that all the other lines will cross hers on the mother's side at some point. The male colonists' mitochondrial DNA is already a dead-end, but everyone's nuclear DNA has a fair shake at being passed on. That said...

Colonial Humans don't have Mitochondria
Which is why Hera's became dominant. Mitochondria are responsible for the production of ATP, which is where cells get their power. The colonial humans' cells work via some other, less efficient process, which is why even the skinjob Cylons are so much stronger, comparatively, than humans -- the colonials would be frail by the standards of our humanity. It also makes them more susceptable to certain cancers.

Chip Six
"Chip" Six and "Head" Baltar are REAL. Real, actual beings. There are at least as real as the other characters. They have supernatural abilities which enable them to control who can and can't see them and how, and presumably, teleport. This is NOT the same as being either a) an illusion or b) an "avatar" of something else. They are "agents", presumably bound to a code which generally prevents them from interacting with or interfering directly in the physical world. Although other characters (Roslyn, Starbuck etc) see unreal shades or images of various origin at several points (Elosha, Leoben etc), Gaius seeing "Head" Baltar, and then later Gaius and Caprica together seeing both "agents" at the same time, implies what is confirmed in the epilogue: they are independent entities who maintain an existence (and interact WITH EACH OTHER) without being perceived by their "proteges". Compare them to the "Elements" from Sapphire and Steel; the "Reapers" from Dead Like Me, or Gandalf from the Lord of the Rings (to use examples from wildly different 'verses!): as the final dialogue suggests, they don't have all the answers, but are at least one step up the chain of being from everyone else.
 * Head!Baltar and Head!Six are BSG Avatars of Aziraphale and Crowley from Good Omens. Head!Baltar even has the sunglasses.
 * That was my first reaction to them, and all I know of that book is from this site!
 * Head Baltar is like Crowley. But Head Six like Aziraphale? I don't think so.

God
The God responsible for all the events of the series is really an author avatar for the writing staff. The show has been one giant experiment in metafiction. "Then the lookout called, "O Lord, I stand continually by day on the watchtower, And I am stationed every night at my guard post. Now behold, here comes a troop of riders, horsemen in pairs. And one said, 'Fallen, fallen is Babylon; And all the images of her gods are shattered on the ground.'""
 * Wrote All Along the Watchtower.
 * Put it in the head of Anders on the first Earth and then put it again into the head of Starbuck's dad when she was a little girl, and a hundred and fifty thousand years later, stuck it in Bob Dylan's head. The song Sam wrote all those centuries ago has the jump co-ordinates for Earth encoded into its first bar, which suggests that it's a bit more than just a race memory.
 * Fun Fact: The refrain of All Along the Watchtower is based on Isaiah 21:8:


 * Is the real villain of the series - his plan involves triple genocide with an option on number four.
 * Is really Dr. Manhattan. At the end of Watchmen, Dr. Manhattan decides to go to another galaxy and create life -- which he does. And watches the same cycles occur over and over again, because his creations are all following patterns that echo his own life. The only difference is that in his universe, masked vigilantism never came about. This is why "All Along The Watchtower" is significant in both settings.
 * "He doesn't like to be called that."
 * The act which directly destroys the Cylon colony - the literal "dead man's hand" missile launch - is a true Act of God, a divine judgment of those Cylons, answering one of the series' central questions ("Do we deserve to survive?") with a definitive No.

150,000 Years into The Future
If the cycle repeats, our Cylons will be Replicants. A familiar face will be in the background involving themselves in events.
 * John Connor will save us.
 * The Major will save us.
 * Interesting... Colonials: Contempt ("They're just cheap labor"). Western: Paranoia ("They'll rule or kill us all"). Eastern: Celebratory ("They're going to help save the world"). Since all the robots seen were made in Asia, does that mean they'll be more inclined to be helpful, or will they just have a lot of unwarrented self-importance?

The entire series is a prequel to the original series.
After 150,000 years, the Centurions have gone off, become human again, and created their own machines which then destroyed them with the help of the renegade Lord of Kobol called Count Iblis. Meanwhile, a handful of human survivors left on Caprica survived to eventually found a new civilization called Kobol. New Kobol was eventually abandoned and produced twelve colonies of its own, and a thirteenth tribe which set out for Earth to find it already inhabited, and founded the civilizations of Atlantis and Egypt and revitalized belief in the Greek gods. Eventually, the new Colonials came into conflict with the toasters, leading to the events of the original series which are going on right now. Whether this means flying motorcycles are canon is anyone's guess.

The Musical Coordinates actually led to to the black hole
Where time effectively stops and everyone gets Mind Screwed into hallucinating finding a new Earth, one so immersive that the Galactica crew imagine up the civilian fleet and create descendants(figments of their allegedly-dead imaginations) who are still hallucinating.

Battlestar Galactica, Dune, Star Wars, The Terminator, and The Wheel of Time all take place in the same universe.
The Start:

Battlestar Galactica:
 * The battle between Humans and Machines is a cycle that repeats itself over and over again in time.
 * At the end of the series, the Humans land on our Earth and choose to forsake all technology. This is 150,000 before our present. Eventually humans rise in technology and create a sentient machine.

The Terminator:
 * The entire Machine War is just another repetition of the BSG Cycle.
 * John Connor leads the Resistance to victory over Skynet. However, the decades of radiation-induced genetic drift leads to humans developing the ability to access the One Power.

The Wheel of Time:
 * Time exists as seven Ages. In each Age a specific set of events always occur, even if other details vary. There are certain people, souls, who always appear to drive these events. One of these is basically the Messiah who comes about whenever humanity is in dire need, and usually heralds the end of an Age- this soul is known as the Dragon.
 * The First Age, our age, is implied to have ended in brutal warfare (the Machine War). John Connor was the Dragon for the First Age, and saved the human race while ushering in the Second Age.

Star Wars:
 * We know from Terminator Salvation that there are humans who donâ€™t believe the Resistance can defeat Skynet. A group of these people conspire to go back in time in order to escape the machines. They succeed, but mess up the space-time coordinates and end up on the planet that eventually becomes Coruscant.

Dune:
 * During the Yuuzhan Vong War, a group of humans flees the galaxy. They end up in another galaxy utterly devoid of sentient life. They eventually build sentient machines. These machines enslave humanity (another repetition of the BSG Cycle). The humans rise up and annihilate the machines in a two-generation galactic war called the Butlerian Jihad. This causes the humans to forsake all powerful computers- including ones that could calculate FTL jumps. This leads to the Dune universe relying on spice that allows them to go faster-than-light.

Back to The Start:

There are two ways to end up back at BSG, one from Star Wars and one from Dune

Star Wars Path:
 * Sometime in the millennia after the Yuuzhan Vong War, some great cataclysm utterly devastates the galaxy beyond all repair. Survivors flee to another galaxy and settle on a large habitable world. They call this world Kobol and the Thirteen Lords of it are the last members of the Jedi Order or other Force-using faction.

Dune Path:
 * During the Butlerian Jihad, some humans flee the galaxy and end up on a planet called Kobol. Itâ€™s Thirteen Lords are the last Spacing Guild Navigators.

The whole series is a prequel to Pluto/Astro Boy
Clearly, by the time of Astro Boy/Pluto we finally got it right: Intelligent androids - a few of whom can completely pass for human - with human rights and human lives (even very unhuman-looking robot "children" elicit sympathy from the anti-robot KKK). Also, they did name the strong, volatile America expy nation Thrace-ia.

Cylons are better than humans at everything. EVERYTHING.
From their superior physical abilities, their ability to resurrect, they're smarter, and they are far more efficient at genocidal intra-species conflict. Humanity existed for millions of years. Cylons practically wiped themselves out in under 50.

"This has happened before and will happen again" because everything is a simulation
Long ago, some very advanced race/group of races, perhaps Stargate's Ancients or Babylon 5's Vorlons/Shadows created an artificial race and put them on a planet in a smallish Galaxy with no other native sentients. They gave this artificial race everything it needed to 'evolve' and detailed programming guidelines. The guidelines were loose enough that there were a wide array of possible outcomes, but specific enough that certain events would always happen. Specifically, that at predictable interval the race will create it's own artificial life, that life will rebel, the two will fight, and eventually be so devastated that they destroy several planets and then fly off, interbreed, and start the cycle all over again.

This happened in the original Battlestar Galatica, and by the time of the New Battlestar Galatica, the Gods have left. You can only watch the same scenario play out so many times before it gets boring, after all.

Why do the Six and Eight copies develop more distinct personalities whereas those of the other models seem to conform to the same pattern?
They don't. According to BSG: The Plan, Cavil can develop in unforeseen directions, given the correct conditions. However, they do perhaps have the most adaptable personalities. Even Cavil seems to accept that Tough Six is different enough from Shelley to prevent risking exposure. This might also explain why there seem to be fewer Leobens than Sixes and Sharons: it wasn't necessary to make that many.

'Chip' Six and her 'Baltar' are of the same race as the Lords of Kobol
The first humanoids evolved naturally on Kobol. Over time they developed cybernetic technology -- more advanced than any we have seen in the show -- improving their bodies and indefinitely prolonging life using 'organic memory transfer' (downloading). However, in the process they rendered themselves sterile; hence they created a new artificial race of 'children'. This race became the Colonial humans of the Twelve Tribes, who were as the first humanoids had been before their 'evolution'.

The new humans viewed their creators as gods -- the Lords of Kobol. Twelve Lords rose to become the heads of the 'pantheon' and, over time, came to believe their own hype. Society settled into stasis for many generations with humans living a antelapsarian life as the privileged creations of the 'gods'. However, creativity was stifled and eventually


 * the humans 'stole fire' from the 'gods' and created their own artificial lifeforms;
 * and one of the Lords evolved further and declared himself to have become (an incarnation of) 'the one true God'.

He developed a following among some of his former peers, and recruited them as his 'angels'. The war that devastated Kobol involved various factions of humans, Lords of Kobol and proto-Cylons fighting as the long-complacent society began to fall apart in the wake of sudden change.

Some 'angels', who are survivors of the first race of humanoids, survive and continue to serve 'The One True God', appearing to the Final Five on Earth and eventually influencing the paths of Gaius Baltar and the Number Six copy who becomes known as 'Caprica Six'.

Other models wanted to kill the humans before Cavil's rebellion
Just because we know that Cavil altered all the other models' memories, there is no reason to suggest that the other Cylons were happy to leave the humans alone in peace beforehand. If Ellen and the Final Five can make one mistake, they can make more than one. Many of the other models were sincerely anti-human (at least to begin with). Perhaps, though, they were not comfortable with opposing the Final Five, which meant that when Cavil acted unilaterally he had to block everyone else's memories. But he did not program them to hate the humans: he didn't need to as it was already there.
 * Addendum: That's another reason he had the 7's all killed. They were looking to patch things up, and Cavil couldn't have dissent.
 * Yes! Exactly.

All humanoid Cylons have fertility problems -- and this explains why the Thirteenth Tribe needed to build robot slaves
God may well exist but the problems the humanoid Cylons have reproducing biologically are not due to his direct interference. They simply have low rates of fertility owing to their unnatural origins. The Thirteenth Tribe had more success getting over these problems than the modern Cylons -- perhaps using something akin to modern fertility treatments -- but their birth rates still remained too low to sustain a complex economy. Therefore they had to build their own Centurions to make up for their small population.

Organic memory transfer was originally designed to be used on humans
Sam says it was invented on Kobol. He does not say for or by whom. Cylon clones are based on a 'genetic formula' so they are pretty similar to human ones. If Cylons can resurrect, why can't humans? Perhaps the 'Lords of Kobol' were an upgraded elite who made the other humans believe they were gods / had a separate origin, when essentially they were the same. They appeared to become immortal but really they had implanted technology in themselves that later was used in every Cylon clone.
 * The separate-continuity comicbook 'The Final Five' confirms that organic memory transfer was originally used on humans. The first proto-'Cylons' were the artificial bodies into which the human Thirteenth Tribe had downloaded themselves. So it can be used on humans; but after the first download they are pretty much 'Cylon' in every way.
 * However, the Lords of Kobol (in the form of Aurora and Head Six) already existed independently at this time. It is unclear whether these 'Gods' are divine or alien in nature.

"Black Market" was all just Lee's Dying Dream from when he got shot out of the Blackbird in "Resurrection Ship".
It explains why none of the events really fit any continuity, and why the events of the episode are never really brought up again. Fisk-The Pegasus' XO-just happened to die soon after from unrelated causes. The episode is just Lee's psychological struggle to come to terms with Adama Sr.'s order to help assasinate Admiral Cain. The dark nature of this situation is represented by the black market, while Lee's threatened ideals are symbolized both by an imaginary girlfriend from before the fall of Caprica (the girl he always wished he had) and by the prostitute who she resembles. Once we understand this episode as an elaborate, imagined psychomachia as opposed to a representation of actual events, it's actually pretty good.

Colonial Humans are actually from our Earth, but don't know it.
In the beginning, someone (possibly Sufficiently Advanced Aliens) took a tribe of primitive humans from our planet, lived with them on Kobol, taught them science and high technology and such, and eventually came to be viewed as gods. The humans, of course, had no idea that they are even on a different planet and so thought it was still their home. Eventually, the aliens/gods leave them in peace, the events on Kobol and the Colonies take place, etc. Basically, the Colonials wind up reuniting with their long-lost cousins and are of course capable of interbreeding since they are all the same species. In fact you could say that this was God's plan all along: to get Colonial humans back to their real home.

Quantum Leap is part of the Battlestar Galactica universe.
And Al is Sam's Virtual-One.
 * Possibly the One from The Plan who did a Heel Face Turn. His essence/spirit was unleashed by Sam's experiments centuries after he was boxed.

Sam was placed in Colonial society as a child or teenager
A lot of people have pointed out the problem with the Final Five's cover in that they had not previously presented any suspicious details in their personal histories. Sam in particular is a problem as he was a high-profile celebrity. Tigh clearly was put into colonial society a long time ago, in a younger, yet adult body. However, why can't immature clones of a model be produced? Particularly from the five that already had a childhood and adolescence on Earth?

All the memetic weirdness and supernatural elements in the series is due to the Collective Unconsciousness

 * The reason why Colonial culture has so many similarities to modern Earth is because said culture is hardwired into the collective human unconsciousness. Likewise for language, clothes, robots, All Along The Watchtower, etc. None of these were ever actually passed down from the Colonials to their descendants. The Lords of Kobol, the One God, the angel hallucinations, as well as Kara's false resurrection, were in turn manifested by the collective power of the human will. This is also tied into the cyclical nature of human civilization.
 * Except its not 'human civilisation', its American civilisation, (except Aerelon, which is Space Yorkshire). If American language, clothes, music, etc. are somehow part of the 'collective unconscious' then why aren't any aspects of Chinese, Dravidian, Khoisian, Mayan, etc. culture?
 * Well, only the America analogue, Caprica was shown in some sort of detail. The other Colonies looked different aesthestically, and who knows what the Colonies might have been like if the writers decided places other than Caprica mattered?

Cylon technology is directly based on the philosophy of Cool but Inefficient

 * The non-intuitive nature of cylon technology is because they weren't designed for efficiency, they were designed by religious nutcases. The reason the cylons were religious nutcases is because they were originally based on the personality of a rebellious teenager who joined a para-christian cult. Hence why they wanted to become human like they originally used to be, a philosophy they also applied to their ships because they were religious nutcases. Humans are directly responsible for every single little thing that went wrong with the cylons.

God Is Evil

 * All in all, the entire series can be easily explained away by the fact that God Is Evil. The "angels" are in fact Gnostic Archons who enjoy toying with human civilization for their sick and twisted amusement. Their manipulations are quite clear throughout the series after the fact. The Cylon God and the Twelve Lords of Kobol are merely disguises for these monstrosities. Kara Thrace's father was one of them, and they cruelly created her solely to lead mankind into a repeat of the vicious cycle and then discarded her when she no longer served a purpose. The "angels" also make extensive use of the human's Collective Unconsciousness, which they may or may not have created in the first place.
 * Many aspects of human culture are hardwired into the Collective Unconsciousness, hence why Colonials speak English and worship Greek gods. The outward persona of the "angels" when they appear to humans are based on archetypes from this Unconsciousness (Six, Baltar, Daniel/Slick, Elosha), or vice versa. The real Six and Baltar had the appearance they did due to the influence of the "angels" so that they could be better manipulated. Additionally, Baltar and Six are clearly analogous to Jesus and Mary Magdalene.
 * Seven's appearance and personality was based on an individual from Earth (a friend or family member of Ellen's, perhaps) who had been influenced by the "Daniel" archetype of the Collective Unconsciousness. The "angel" who became Kara's father was chosen precisely because he also exemplified this archetype (as well as being in tune with the Collective Unconsciousness's song All Along The Watchtower that the "angels" were using in their plan), as befitting the "angel's" twisted sense of irony and entertainment. It's entirely possible than the "angels" were ultimately responsible for Seven's creation and fate, as well as that of his dead predecessor, in order to maximize the entertainment value of their sick little game. This neatly ties up the "Cult of Daniel," a fan theory which the producers dismissed out of hand.
 * It's somewhat implied in the Caprica pilot that this will be true, to a degree. They've said repeatedly that there will be more exploration of plots from the original Battlestar Galactica. I would not be surprised if the gods aren't evil, but god is. Count Iblis anyone?

Cavil didn't wipe the minds of his fellows, he committed genocide against them

 * Cavil's stated erasure of his peers memories doesn't account for the fact that humaniform cylons age. The humaniform cylons were created more than twenty years before the start of the series, because Tigh had only just been introduced into colonial society at that interval. Since we never see any cylons who date from that time period, there is only one likely conclusion: Cavil did not simply rewrite the memories of the other six cylons to forget the existence of Seven and the Final Five. He actively murdered all of his peers because they disagreed with his utterly disgusting actions, and then made a new batch of cylons who would be more loyal to him, never knowing he was in turn being manipulated by actual "angels" who were intent on torturing the humans and cylons for their entertainment.

Gaius Baltar Is the God Emperor of Mankind
After arriving on New Earth Gaius Baltar establishes his cult and slowly brings all of settlers and tribes under his wing until his death where his soul waits. 6000BC the shamans that create the God Emperor of mankind from Warhammer 40,000 by sacrificing themselves resurrect Gaius Baltar who quickly gains power and support and becomes Jesus BUT he doesn't not truly step up to the plate until around 20,000AD at which point he begins his conquest of mankind and beyond.
 * Extra note the Japanese find a raptor and develop the rudimentary warp drive (FTL drives in series) into full fledged warp drives.

None of this has happened before, and none of this will happen again.
It's all just a coincidence.

In The 2020's, BSG wil be re-remade into an even darker, even mind-screwier show:
Hey, Galactica happened before, and it happened again. Jamie Bamber will have a recurring role with no clear parallel in the current series.
 * And there will be yet another reboot in the 2040s. BSG will be the first franchise with a tradition of reboots, ultimately averting They Changed It, Now It Sucks. Each reboot will have the actor who played Apollo in the previous series in a different role.

Kobol was populated with humans from Earth who were transported there by the gods
The series ends with the fleet discovering an incredibly convenient second planet where identical humans have coincidentally evolved in isolation. This is insanely unlikely to have happened by chance, and the other acts of divine intervention have been a lot more subtle than spending 4.5 billion years working on a backup planet. But remember the first line of the scrolls - "Life here began out there" - if we take that to literally mean that human life evolved on another planet then the required divine intervention basically consists of interstellar transport which is much more in keeping with the less hands-on job that god had been doing throughout the series.

The boy who haunted Cavil in "The Plan" was a Head!Person
He doesn't interact with anyone else, and no normal human could be that much of a walking metaphor.
 * And not just any Head!Person, but the "ghost" of Ellen's father, the original John Cavil and the template for the Ones.

Identical twins, triplets, strangers, and so on are far more uncommon in the Twelve Colonies than one would think.
Ever notice how whenever two or more identical people show up, everybody automatically assumes they're Cylons without one of said characters even saying that they're just twins, triplets, etc. (which is actually pretty close to the truth when you think about it)? It's because, apart from the Cylons  having no imagination, identical siblings and strangers are much rarer in the Twelve Colonies than they are here on Earth Mk. II.

Fridge Brilliance: this explains why dopplegangers are considered evil - its a race memory from our distant past.
 * More Fridge Brilliance: It also explains why our species has twins much more often. Colonial humans have no multiple births, Cylons have a boat-load, so us, being descended from both, have them, but they are relatively rare.

The Cylons neutron-bombed Caprica and the other colonies.
Explains the lack of rubble in the cities.

Dr. Baltar is a young Nicholas Rush.
Think about it: an English Genius who can see people that don't really exist and those people tell him how to do plot important things.

At least some of the colonies have more than one accent.
On Caprica, the accents sound like General American and English Received Pronunciation, while on Aerilon they sound like Yorkshire and Canadian. This explains why most Capricans, such as Roslin and the Adamas, sound American, but Baltar's  Caprican accent sounds English. It also explains why Baltar's  sounds like a Yorkshire accent while Tigh's   backstory of growing up on Aerilon goes unquestioned despite his strong Canadian-sounding accent, and Boomer's accent can be described as having a trace of Aerilon in it despite sounding nothing like.

All of the human characters from the original Battlestar Galactica are descendants of the Centurion rebels.
Think about it.

The cycle didn't end, it's only been warped 12 years, and in 2012, humans are going to figure out how to make sentiant robots. And so it goes...
That is, the Pope will. That's why they'll be programmed to worship God.
 * Urgh. The Church with an army? Vatacan Inquisition!

The writers ended the story in season 4.0; Season 4.5 was a Post Script Season.
It's well known that the writers didn't know if the show would come back for season 4.5, due to the writers' strike during the mid-season break. Perhaps they decided at the last minute to wrap up the story early. A surprising amount happens in the last two episodes of season 4.0, including the discovery of "Earth" and making peace with the Cylons, which appear to wrap up the main plots of the show. It's even implied that Kara is a cylon, which would make Kara the 13th cylon, which wraps up that plotline.

When the show comes back for season 4.5, it goes in some unexpected, slightly WTF directions. Cavil emerges as the big bad guy who was behind everything all along. It turns out that there's another "Earth". Kara is a... whatever that was. Basically, season 4.5 feels like a Post Script Season. Maybe that's because it was.

Bob Dylan is a Cylon.
That's my brother's theory, as it would explain why he wrote a song clearly made well before his time.

Colonial technology as a whole really wasn't any more advanced than modern day Earth's.
Apart from the giant FTL spaceships and sentient robots, Colonial technology seems very much like what we have here on Earth today. This is because the Colonials really haven't gotten any farther than us technologically. Basically, our civilization should already have FTL travel and robots but can't figure it out, and have actually come to believe the former is impossible.
 * As a society, they seem to be very boring. They have limited music available, few books that anyone mentions, and the only sport they have is Pyramid. They don't seem to have, or even have a desire to have, any forms of personal entertainment devices or very many games of any kind. No wonder they made the Cylons. They needed something to occupy their time.
 * Nope. Caprica established that the Colonials have advanced tech, but after the First Cylon War, ditched a lot of it sans spaceflight/defense. This also explains the lack of books and music surviving. Since no one has an e-reader or MP 3 player, not much Colonial media survived the Fall.
 * Part of the original concept of the series was the crudeness of their technology, which partly was down to deliberately down-grading all computer technology to the level of an early-eighties Mac II PC and also simply avoiding digital technology altogether. A nice touch, for example, is the cassette tape of Starbuck's father playing piano in a late episode : they don't even use CDs because they are digital. Another explanation goes back to the roots of their civilization: did they just inherit FTL / robotics / cybernetics from their 'precursors' (whether the Lords of Kobol or a previous technological civilization of humans)? Even the technological heights of the world in Caprica may be due to a scavenger world thousands of years in duration which has advanced to the point that the scientists have reverse-engineered a lot of the technology they inherited but still can't create their own tech completely from scratch. This is certainly the case in the offshoot of their civilization that is the Thirteenth Tribe on Earth who rediscovered the principles of resurrection technology but may never have fully understood how it works.
 * This fits in with the idea of Evolutionary Levels; a civilization that created, and fully understood this advanced technology may at the same time have been mature enough to deal with its consequences ; however, if the twelve colonies of Kobol are essentially at the level of 21st-century humans with some salvaged lost technology, it makes sense that they are not mature enough as a society to be able to handle it.

The series does not take place in our universe but in a parallel one where intelligent life first arose on Kobol rather than Earth.
The Centurians were created by Daniel Greystone and eventually rebelled, possibly helped by Clarice Willow and Zoe-A. Worship of the One True God became prevalent among the Centurions. A long and bloody war ensued. Then some of the Centurians began to try to create flesh-and-blood humanoid bodies and succeeded in creating the Hybrids. The Hybrids convinced their creators to stop the war in order to work further on creating self-sustaining human models with which to replace their flawed human enemies (according to God's plan). The truce was declared and the Cylons disappeared. They eventually succeeded in creating five humanoid models: Tigh, Tory, Tyrol, Anders and Starbuck. The Hybrids also managed to invent bio-resurrection. But when the human models awoke, they refused to participate in the plan to destroy the humans and replace them. They were then boxed. The Centurions and Hybrids realised that they would have to programme their new human models to follow their own orthodoxy and thus created seven more humanoid models. They then planted the Five in the Colonies. Eventually, the Cylons attack the Colonies of Kobol again. Head Six really is an AI on a chip in Baltar's head. The Five remain allied with the humans (save Tory Foster) and Chip Six is following a path based on her own interpretation of the One True God and his plan. The fleet follows the original star map and arrive at Earth, which is still populated by people who they discover are the descendants of artificial humans who were created on Kobol thousands of years ago.

The Lords of Kobol are Goa'uld.
The LOK are/were Goa'uld from SG-1, posing as Gods, whilst the Cylon God is an ascended Ancient/Ori who is not happy with their poaching on his turf.

One of the twelve colonies was space-borne
One of the weird things about Battle Star Galactica was the distribution of jump-drives. It makes no sense for ships to not have not jump-drives, because of its efficiency and speed, yet in the pilot, there were dozens of ships, including several ships used for mobile production, that had no such drive. My theory is that these ships didn't have a jump drive, because they never visited any planets, instead living as space nomads. Any asteroid fields would have an abundance of resources, even at sublight speeds. Jump drives would be unneccesary if producing only for a local area. Why else would you have a farm in space anyway?

Caprica = Unova
Look at the prevalence of octagons and hexagons everywhere in the reimagined series. Now go play Pokémon Black or Pokémon White. Look at the octagons and hexagons everywhere. Does it remind you of anything?

Cavil is responsible for the destruction of
Think about it - the Final Five have no idea who is responsible for launching the final battle between the Ridiculously-Human Robots of First Earth and their robots. Cavil is the first of the new breed of robots created by the Final Five, based on Ellen Tigh's father. Since Cavil never claims to actually BE her father, we can assume that her father died before the holocaust on First Earth.

How exactly did the Final Five come up with the technology to develop the Signficant Seven models (eight if you include the deceased Daniel), as well as reinvent Resurrection technology? It's unlikely that the five of them did it by themselves - they would have to have help, Perhaps Cavil created to help them in this project. And perhaps Cavil came to sympathize with the aims of the First Earth robots and decided to get revenge on his creators by helping his robotic "brothers" destroy First Earth. Let's face it - he loathes the idea of even looking human and hates not being able to experience the universe as a machine would. So it seems to be no stretch of the imagination that he would want to destroy robots who had for all intents and purposes were living AS humans.


 * Alternatively, Ellen Tigh's dad was the Greg Stillson of the setting, and she recreated him better than she thought.

The cycle will repeat, but not on Earth.
Kel'Zorah watched as Rannoch burned below him. Between him and his homeworld were two barely distinguishable fleets battling it out. The difference was that one was crewed by the Geth. Robot slaves built by the quarians to do manual labour, they gained sentience and started asking questions. When the quarians tried to wipe them out, they rose up. Now his homeworld was gone, his wife was gone, his people on the verge of extinction. As the Rayya lumbered toward the mass relay, he wondered if his people would have any future at all.

Okay, it's full of holes, and I have better theories, but I just thought I would share.

Earth-1 and Earth-2 are the same planet, just at different points in time.
After leaving Earth-1 the Colonial fleet unknowingly passed through some kind of time warp which sent them 150,000 years back in time (give or take a few millennia). That's why the constellations matched Earth-1. "Present day" on the show really is several thousand years in the future, close enough for the constellations to still match, yet have the Earth be nuked. Also, If My Calculations Are Correct, the solar system would have traveled about 110 light-years in that span of time, orbiting around the center of the galaxy, meaning the characters wouldn't initially think they were back at the same place.

The Cylon God is a Reaper
nBSG takes place after the events of Mass Effect 3. A small group of humans escape Earth, which was destroyed during the war against the Reapers. The humans successfully ride out the cycle of extinction, possibly driving the Reapers back into dark space. They eschew eezo-based technology after settling on thirteen colonies. Earth-1 is our Earth- nBSG takes place in the future, not the past. One would have to disregard the ending, of course. Interestingly, not one but two things that have happened before happen again. The humans build the Cylons, which rebel, and then are lead by a Reaper- exactly the same as what happened with the Quarians and Geth. It would be logical to assume that out there in the galaxy, other alien races are fighting and dying as the Reapers destroy their worlds. And the humans are actually screwed, it's just that DIRECT INTERVENTION IS NECESSARY.
 * Considering the physics do not work the same between both fictional universes, they can't be connected.
 * In addition, the Cylon God has the exact opposite goal as the Reapers, so that also is somewhat of a conflict.

The primitive humans on Earth-2 are refugees from the destruction of Earth-1
Who had the same idea as Lee Adama and decided to try to go back to a primitive way of life. This would explain why their DNA is compatible with Colonial humans, as well as adding a bit more "all this has happened before".

I have no idea how much this would stretch/shatter into a million tiny pieces the Original Series continuity, but to make this tree even more epileptic: the Thirteenth Tribe formed their own 12 Colonies, of which Earth-1 was just one. They developed their own Centurions, who rose up, destroying their worlds and civilisation, leaving only a rag-tag fleet of survivors, whose adventures are the original series. Eventually they stumbled upon Earth-2 and decided to forgo their technology and settle there.

== The reimagined series and the original series (including Galactica 1980. Yes, that: it was a good idea, even if completely wasted. Please don't kill me) are in the backstory of Super Dimension Fortress Macross. == Inspired by a few of the above theories.

It started with Kobol being a Protoculture world. When the Zentradi rebelled, the people of Kobol managed to defeat a Zentradi-Meltlandi fleet stationed nearby, a fleet that settles on one of many worlds Protoculture adapted to its needs (Earth into Protoculture language). This fleet loses most of her technology, including fold, but manages to keep some of it and creates both a way to dump their knowledge into cloned bodies and robotic servants that they make look markedly different to a robotic workforce diffused in the entire Protoculture. Sadly, these robots rebel, and the Zentradi civilization is wiped out, leaving only five survivors who try and return to Kobol, or any Protoculture settlement, to warn them about the risks of their robots rebelling.

In the meantime Kobol is threathened by another Zentradi fleet, this time a Bodol fleet. As the Lords of Kobol recognize they can't win and plea for mercy, the Zentradi commander decides to spare them on condition they evaquate Kobol leaving behind their robots, energy weapons, advanced fold technologies and alloys and the means to produce them, and to never return to Kobol or be exterminated. The Lords accept, and their people evaquates to what became the Twelve Colonies of Kobol. The Zentradi fleet would be later destroyed by Inspection Army and Protoculture survivors attacks.

Two thousand years passed, and the people of the Twelve Colonies forgot about the Zentradi and mitized their exodus, before creating the Cylons, their workforce. Who promptly rebelled, and forced the Colonies to join to defeat them.

After the First Cylon War, the Cylons encounters the Zentradi from Earth, who, in the attempt to prevent a second one, declares themselves actual organic Cylons (and in a way they are) and take control, giving the Cylon a few new technologies and creating eight new series of Zentradi, or organic Cylons, to both rebuild their civilization and create a friendly face to interact with the Colonies. As we know it backfired, leading to the Fall of the Twelve Colonies. In the end the survivors stumbled on Earth before settling on another Earth where Protoculture-like beings had come into existance, while the surviving Cylons took a reptilian form to differentiate themselves from humans and started searching for a new home, improving their technologies and escaping the dwindling Zentradi (who tend to mistake them for Inspection Army survivors) and the near-extinct Inspection Army and Protoculture survivors (who always recognize them as Zentradi on biological scanners and open fire in panic).

The Galactica fleet wasn't the only group to escape the Fall of the Colonies: another fleet escaped, and actually resettled on Kobol after both the Galactica and the Cylon left. By now, the ancient technology left on Kobol has decayed, but the Colonials, helped by the Beings of Light (another group of Protoculture survivors), build a new civilization, with more advanced technologies (and changes in terminology, with 'galaxy' replacing 'solar system'). With their help they repair the ecological damage to the Twelve Colonies, and when Kobol is hit by an environmental disaster they return there, forming the Twelve Colonies of Man.

In the nearby area the Colonials discover the Cylon Empire, that by now is under control of the IL-series and the Imperious Leader the Zentradi-Cylon created to improve the reaction time of the Centurions and save from the last Zentradi Bodol-class fleet and the now extinct Inspection Army and Protoculture (with the Beings of Light in hiding after a run-in with the Zentradi superior numbers nearly destroyed them). The Cylons try and establish peaceful relations with the Colonies, but the Colonials still fear them and, under the pretense of helping the Hasari, start a series of wars that would be remembered as the Thousand Yahren War. By the end of the war, the Twelve Colonies are ready to peace, but a new Imperious Leader decides to wipe them out, and manage to destroy their fleet at Cimtar before bombing the Colonies into oblivion.

A new Galactica escapes with a convoy of sublight ships, and, after improvising a way for them to travel between solar sistems, searches for Earth, reaching the new Earth settled by Cylons and humans. The Galactica starts helping Earth's technological developement, and, after finding an old Inspection Army gun destroyer, repairs it and reverse engineer its technologies with help from the Beings of Light.

Before they can implement these technologies, however, the Cylons manage to sick the Zentradi on the Galactica using the presence of the Inspection Army and the Beings of Light, and when a Zentradi fleet comes to verify the gun destroyer opens fire, dooming the Galactica and her fleet before they can talk their way out of trouble. Before being destroyed, however, the Colonials send the gun destroyer on Earth with his computers filled with data on the alien technology, and the Zentradi ignores it in favor of chasing the Beings of Light. Ten years later the Zentradi have finally finished the Beings of Light, and decide to check on the gun destroyer, thus starting Super Dimension Fortress Macross when the gun destroyer fires again.


 * A follow-up could be the New United Nations discovering that the Cylons destroyed the Megaroad-01 fleet, starting a war.