Hiroshima as a Unit of Measure

"Are the radio-waves from objects in space any threat to us? No, they are extremely weak. The total energy collected by radio astronomers over the history of radio astronomy amounts to about the energy required for a mosquito to make one push-up!"

- Dr. John Simonetti of the Department of Physics at Virginia Tech

""This, recruits, is a twenty-kilo ferrous slug. Feel the weight! Every five seconds, the main gun of an Everest-class dreadnought accelerates one to one-point-three percent of light-speed. It impacts with the force of a thirty-eight kiloton bomb -- that is three times the yield of the city-buster dropped on Hiroshima back on Earth! That means SIR ISAAC NEWTON IS THE DEADLIEST SON OF A BITCH IN SPACE!""

- Gunnery Chief, Mass Effect 2

How do you show someone the force of an erupting volcano via print, or the height of the Burj Khalifa over a 17-inch screen?

No matter how huge something may be, it's hard to wrap your mind around the scale of it without seeing it for yourself, or having some point of reference to compare it to.

That's where this trope comes in. A simple way to show the size of something is to compare it to something else that a lot of people are familiar with. That's why many documentaries, especially ones of the "World's Biggest Whatever" variety, will use measurements that compare things to familiar or historic events, places, and objects.


 * Energy (especially released by explosions) will be measured in atomic bombs dropped on Hiroshima.
 * Height will be measured in Empire State Buildings or Eiffel Towers.
 * Volume will be measured in Olympic swimming pools.
 * Length will be measured in trips to the sun, times around the Earth's equator, or distance between the Earth and the Moon.
 * The mean distance between the Earth and the Sun is used as an actual unit of measurement, the Astronomical Unit (AU).
 * Small lengths will be compared to the thickness of a human hair.
 * Also acceptable is the head of a pin, as in how many of what can fit on one.
 * Area will be measured in football fields, or compared to that of some region (Wales, Texas, Switzerland...).
 * Weight will be measured in sacks of concrete, Boeing 747 jumbo jets, or large animals.
 * Amount of money will be measured as the height of a stack of that much money in one-dollar bills using one of the length measures.
 * Large amounts of money will be measured as the length of that many one-dollar bills laid end-to-end, using one of the astronomically-sized length measures, e.g. "If the National Debt were in dollar bills and you laid them end-to-end, it would stretch all the way to the sun and back 8 times."
 * Small spherical objects will be compared either to fruit or sporting equipment (grapefruit, golf-balls, etc).

Basically, any unit of measure that equates to something extreme in that property, but is still rather vague and hard to comprehend since the average person doesn't know what that is off the top of his or her head. Bonus points if the number of the unit of measure is still ridiculously large (e.g. 1,000,000 Hiroshimas) thereby defeating the purpose of describing it in those terms even if the unit was something people would intuitively understand.

This trope is for unusual units for quantities that have well-defined values in ordinary non-facetious units. If you measure an amount of something that usually is not given a numerical value at all, it is an Abstract Scale. See also Fantastic Measurement System.

Comic Books

 * There is a story by Carl Barks with Donald Duck and his nephews, where they are travelling into space via a virtual machine Gyro Gearloose made. Donald takes them to bigger places where he recreates earthly stuff on vast scales, constantly using comparative scales for his nephews and the readers to grasp. This is mixed with using objects of continuously lesser scales -first insects, than dust, snowflakes, etc- surpassing them. The story is called 'Donald's Big Imagination'. A grasshopper from Betelgeuse is imagined having 5 ocean liners on its back and the circumference of the star uses a time-scale analogy, namely "Earth's fastest rocket takes 100 years to fly around it".

Film - Live Action
"President: How big are we talking? Scientist: Sir, our best estimate is 97.6 billion-- Dan Truman: It's the size of Texas, Mr. President."
 * The movie Armageddon uses this trope while describing the size of the asteroid.

"SSgt. Sykes: You take what you know, and then you multiply. Please don't use your dicks. They're too small, and I can't count that high. I don't wanna hear, "400,000 inches.""
 * This makes it a whole lot more threatening than the other asteroid movie, Deep Impact, featuring a comet described as "The size of New York City, from the Battery to the Bronx."
 * The opening narration also used the "Hiroshima measurement" when speaking of the asteroid that wiped out the dinosaurs. Hilariously, even though they try to make it sound impressive, they severely underestimate the energy released by the real impact.
 * Parodied in Team America: World Police, where it is noted that an upcoming terrorist event, if it completes, would be "Nine Eleven times a hundred" - as is pointed out, that's 91,100 ("basically all the worst parts of the Bible"). Another is "Nine Eleven times a thousand" - 911,000. Kim Jong-Il described his ultimate plan, which involves simultaneous terrorist attacks with weapons of mass destruction across the world as "Nine Eleven times 2356," which nobody knows.
 * In Jarhead, this is noted as a legitimate military tactic to quickly gauge distances: use things you know, such as the length of a football field.

"Coffey: Twenty-four Trident missiles, eight MIRVs per missile. Lindsey: (Beat) That's a hundred and ninety-two warheads, Coffey. How powerful are they? Coffey: The MIRV is a tactical nuke. Uh, fifty kilotons, nominal yield, say... five times Hiroshima. Lindsey: Jesus Christ. It's World War III in a can."
 * In the film The Giant Claw, the Special Effects Failure creature is constantly compared in size to a battleship.
 * Sunshine's Icarus Two is built around "a stellar bomb with a mass equivalent to Manhattan Island".
 * In The Abyss, Lindsey asks Lt. Coffey how many missiles are on the wrecked sub they are investigating:

"Foreman: ...twice as tall as the world-renowned Eiffel Tower, or thrice as tall as the famous Notre Dame de Paris, incidentally, that's French for "Our Lady of Paris". Brute: (nonchalantly) Whose lady was that? Foreman: (taken aback) Our. Of Paris."
 * In Cradle 2 the Grave, the second-most powerful setting of the superweapon is described as "two Hiroshimas". The number-one most powerful setting is described as "new world order".
 * That scene is full of these, starting with a SCUD missile. However, they're making a presentation to a bunch of terrorist and rogue state leaders, who are probably not rocket scientists.
 * The Soviet movie Operation Y and Other Adventures of Shurik has this personified in the construction foreman - he gives a lengthy speech consisting entirely of this trope, culminating in one of the movie's many Crowning Moment of Funny.


 * In Help!, as The Beatles record a song in the middle of Salisbury Plain with the Army protecting them, the bad guys burrow underneath, setting a massive amount of explosives labelled in military-grade stencil "Equal to exactly one millionth of the explosives exploded in one week of the Second World War".
 * In Independence Day, when describing the mass of the alien mothership, it's said to be "a quarter the size of the moon."
 * It's also described as being over 550 kilometers in diameter, which gives it roughly 20 times the average density of solid lead.

Literature

 * A children's book called the I Wonder Why Encyclopedia occasionally measures weight in terms of small cars despite also giving actual units and somehow deciding that cars weigh exactly one ton.
 * The problem with this is that it's a moving target. A "mid-size" 1981 Dodge Aries and a "small" 2008 Toyota Yaris both weigh about 2500 lbs.
 * In Fred Saberhagen's "Berserker" series, the Berserker enemy A.I. spaceships are often described as the size of Manhattan Island. Which for a space ship is HUGE.
 * New Scientist's Feedback column maintains a discourse on unusual units used in media and advertising lasting probably since its inception - London buses, blue whales, football pitches etc etc etc.
 * The children's book How Much Is A Million teaches kids about large numbers in this manner.

Live-Action TV
"Graham Chapman: Well, if you can imagine the size of Nelson's Column, which is roughly three times the size of a London bus, then Tchaikovsky was much smaller. His head was about the same size as that of an extremely large dog, that is to say, two very small dogs, or four very large hamsters, or one medium-size rabbit if you count the whole of the body and not just the head."
 * How Do They Do It described a ship as "the length of three football fields" and "six times the size of the Titanic" within one minute.
 * Killer Asteroids on the Science Channel describes asteroids' power in terms of Hiroshima bombs.
 * The narration writers for The History Channel series Modern Marvels love these, even when they're less than helpful. Particular favorites are "the thickness of a human hair" or some fraction of it; aircraft carriers for size or volume; and football fields, or "Los Angeles to {insert appropriate city}" for distance. Before you can describe something's size in units of aircraft carriers, you first have to mention that an aircraft carrier is the length of 5 football fields.
 * The Doctor Who Children in Need special "Time Crash" said, as a joke, that the explosion caused by the time crash make a hole in the space-time continuum exactly the size of Belgium. The Fifth Doctor remarks that Belgium (as a unit of measurement) is a bit underdramatic, but a bit later uses it as a shorthand for the catastrophe, as in "Two minutes to Belgium!"
 * The "How to be Well" public service announcements on Nickelodeon stated that one pecan pie has the same amount of fat as twelve cheeseburgers.
 * Many documentaries on ships will give the size of the ship as measured in Titanics.
 * Parodied in Monty Python's Flying Circus, as part of a spoof documentary on Tchaikovsky.

""Rand & McNally will have to redraw their maps.""
 * In the last episode of Cosmos, Carl Sagan compared the total tonnage of bombs dropped in World War II—about 2 megatons of TNT—to the yield of a single modern strategic thermonuclear weapon. The tonnage of bombs and warheads we could theoretically drop in World War III, he said, would be "A world war 2 every second, for the length of a lazy afternoon."
 * He then went on to say that this was the equivalent of a million Hiroshima bombs.
 * The Angel episode "Time Bomb" had the demoness Illyria threatening to implode and, according to Wesley's conservative guess, take out several city blocks. Angel requests an "unconservative" guess.


 * These kind of measurements come up on QI from time to time. Apparently the UK purchases enough wrapping paper for the Christmas season every year to gift-wrap the island of Guernsey.
 * One episode of The Colbert Report had Stephen rating Nazis on a scale of 1 to 10 Hitlers. Adolf Hitler himself got only 9 Hitlers because "nobody gets 10 Hitlers."

Tabletop Games

 * Advanced Dungeons and Dragons, 1st Edition, used the gold piece as a unit of weight. Your carrying capacity, the lifting power of a telekinesis spell, the load limit of Tenser's floating disc, etc. -- all these were given in units of gold pieces rather than pounds. (At the time, 1 gold piece weighed 1/10 of a pound, so converting between pounds and gold pieces was rather easy, although it did make for some ridiculously heavy coins. When 2nd Edition came out, the weight of 1 gold piece changed to 1/50 of a pound and the notion of listing weight in g.p. was abandoned.)

Video Games
"Grobnar: No one really knows how big the Wendersnaven are. They could be thousands of Khelgars high! Khelgar Ironfist: What did I say 'bout usin' me as a unit of measurement?! Grobnar: Er, right, several Neeshkas high."
 * Katamari Damacy uses this form of measurement to illustrate the size of your katamaris.
 * Mass Effect tends to use Hiroshimas to quantify the yields on starship mass accelerators, both in-game and in the Codex. The above quote is a gunnery captain chewing out a pair of recruits about just how powerful the gun really is, to get them to "check [their] damn targets" before firing. Also, in Mass Effect 1, Admiral Hackett will use it to describe the size of a tactical nuke attached to a recon probe launched during the First Contact War.
 * Grobnar of Neverwinter Nights 2 starts using his team mates as a unit of measurement.


 * In Super Paper Mario, when Dimentio first brings the heroes to Dimension D, He believes that his power has increased by 256 times, and he claims that he could obliterate the heroes with the amount of power it would take to lift an eyebrow.

Webcomics
"Yakmeat: Every time we run a simulation, we are literally creating an entire artificial universe to experiment with. And when an experiment is over, we're just turning off quadrillions of lives. Phillip: I can't conceive of a quantity that large. It's meaningless. You're speaking jibberish. Cornhusk: Each termination can be reduced to a function of 3.5 billion times the number of people exterminated by Adolph Hitler in your level's second world war. Phillip: Oh my God. 3.5 gigahitlers? Each time?"
 * Faye in this installment of Questionable Content claims to be a unit of measurement, but the formula is rather complex.
 * This Saturday Morning Breakfast Cereal strip pokes fun at the tendency of science TV programming to do this.
 * Xkcd gives us several of these here.
 * In Order of the Stick, Belkar's Evil levels are measured in Kilonazis, with a hypothetical offspring of Cruella de Ville and Sauron as a point of reference.
 * In Goats, Phillip needs one of these to comprehend the number of people he's killing every time he creates and destroys another universe:

"like "mr president theres a meteor coming sir." "oh yeah, how big is it?" "its the size of texas sir" "OH SHIT" "or, how big is it? its the size of new york city sir" "OH SHIT" "sir im afraid the comet is the size of your moms dick" "OH SNAP" "sir are you familiar with jupiter" "you mean like the planet?" "yeah" "well its that big sir" "hmm that sounds pretty big. i have a question, is it jupiter?" "yes sir, earth is literally under seige by planet fucking jupiter" "OH SHIT""
 * One Achewood comic cites the made-up unit "the fermule" as "the basic unit of physics." One reader lampshades the silliness of this in the comments section: "That's right. Losing control of a 200 kg van on an icy road while traveling at 45 mph, skidding off a 45 degree turn and wrapping that van three times around a tree takes a total of 67 fermules of physics."
 * In Ansem Retort, a plan devised to get Zexion elected governor of Pennsylvania by getting his opposition murdered is measured by Zexion in Michael Corleones.
 * Dave in Homestuck mediates on this trope over instant messaging.

Web Original
" I think I've found an excellent unit of size measurement. It's the 'I could kill you and hide your body in it' unit. People usually become very quiet after you say, "yea, I could kill you and 3 other people and hide the bodies in this""
 * One bash.org contributor came up with one:

"Narrator: In order to transmit the same amount of information on paper, they would have to arrange for a 747 cargo freighter packed with telephone books and encyclopedias to power-dive into their unit every couple of minutes, forever."
 * Technology discussion boards have used "Libraries of Congress," in reference to the physical U.S. legislative library of the same name, as a measure of storage capacity. Various actual figures are occasionally tossed around as a baseline (often hovering in the tens of terabytes), but they vary widely, and now that people with a cursory knowledge of computers are familiar with kilo, mega, giga and terabytes, the term is now used as a joke more often than not.
 * A similar comparison was used in Snow Crash to describe the speed of the novel's fiber-optic data transfers:


 * Knowledge engine Wolfram Alpha is programmed to give a few examples when it gives an answer involving any sort of units. It doesn't always get the "well known" part right and does things like comparing lengths of time to equinox precession periods.
 * The Furry Fandom has historically had the "Meeko", used to compare the sizes of plush toys (20 inches, the size of a certain Meeko plush).
 * When the fanbase compared the size of Super Smash Bros. Melee's "Final Destination" stage to that of Brawl, someone had the idea to use a character, cloned and stood end-to-end, as a unit of measurement. The result? Melee's was "thirteen-and-a-half Falcons long". Brawl's was thirteen. There was another attempt to use Samus Aran as a unit of height.
 * Cracked.com's go-to comparison for crazy behavior is none other than Gary Busey.
 * The Sci-Fi Writers Have No Sense of Scale page on this very wiki measures the distance to the nearest star in terms of U.S. National Debts worth of gasoline that it would take to drive there.
 * An epic HP fanwar provided a unit of measure for insanity, thanks to one Lady Darkness insisting on being married to Snape on an astral plane: "One Ladark (...) is defined as the amount of batshittery necessary to believe a fictional character originating within the last 20 years is real and speaks to you. Most wanks can be measured in milliLadarks. This one hits about three."
 * Certain fans on the internet have made the Henderson, a unit of plot derailment, particularly of tabletop RPGs. It's creation was inspired the story of Old Man Henderson, the man who "won" Call of Cthulhu (tabletop game) (which is practically impossible). Henderson was a highly eccentric (and slightly psychotic) Player Character devised to get back at a particularly agitating GM in the most imaginable ways possible. His exploits include: burning a Shoggoth, stealing a yacht from a Hastur cult, dropping said yacht on a Cthulhu cult's penthouse (and starting a cultist gang war), The tanker truck incident, and "Hell on Ice". Henderson's exploits included a surprising number of counts of arson, most accidental, and accidentally killing a lot of people, including the every other player's characters at least once, and incidentally, everybody who could link Henderson to a crime.

Real Life
"I know what you're thinking when you say it: "An area the size of Wales, [angrily] but not Wales!""
 * As a less cartoonish and possibly more awe-inspiring alternative to the page quote, Carl Sagan described all the energy collected from outside the solar system by radio telescopes as "less than the energy of a single snowflake striking the ground."
 * The yield of cataclysmic explosions is frequently measured in terms of number of Hiroshima equivalent.
 * They are almost always measured in kilo/megatons. That means that they are as powerful as that many thousand or million tons of TNT. Little Boy, the bomb dropped on Hiroshima, was somewhere between 13 and 18 kilotons.
 * Wikipedia also uses the Tsar Bomba, the biggest nuke ever made, to measure the eruptive power of the the Krakatoa eruption. (Hint: 1 Tsar Bomba = 3,125 Hiroshima bombs, and 4 Tsar Bombas = the Krakatoa eruption)
 * The energy released by a large meteor impact (like the one that killed the dinosaurs) is often likened to collecting all the nuclear weapons in the world to one spot and exploding them all at once, then repeating it about 1,000 times within the same second (for a more precise comparison, the energy released by the impact of a meteor with a 10 km diameter is about 100,000,000 megatons. The Hiroshima bomb was 0.016 and Tsar Bomba 50 megatons).
 * Most geologists get a little tired of this. The energy of earthquakes, volcanic eruptions, and bolide impacts is primarily transmitted into the ground as compressional and shear waves, or lifts ejecta into the air. The actual destructive effects of these phenomenon are far less than detonating some imaginary bomb that contains the same amount of kinetic energy, since in a nuclear bomb that energy is released mostly as gamma rays that directly heat the atmosphere causing an explosion as the air expands to cool itself. The total kinetic energy released is not equivalent to the actual effects of the release. Detonating a 1 megaton bomb will cause far more damage to human structures than a 1 megaton volcanic eruption or a 100 megaton earthquake, even when a lot of the bomb blast's kinetic energy is lost to space and the upper atmosphere.
 * In America, many people will emphasize how small or remote a town is by listing the miles to nearest Wal-Mart, McDonald's, major grocery store, or multiplex.
 * Hint: You're never farther than 115 miles from a McDonald's
 * This doesn't include Alaska. If it did, it'd be a lot further than that.
 * under 40 km in Germany! source. Unless you count Helgoland, where the nearest restaurant seems to be in Cuxhaven, some 60 km away.
 * City size can also be described similarly; Sunnydale, for instance, is "a one Starbucks town."
 * In America, Rhode Island's status as the ultimate in mass land-area equation technology is legendary, it having been founded for just such a purpose by the British to convey meaningful analogies of claimed territories to the Throne. If the area being described is too big to be measured reasonably in Rhode Islands, it's often measured in Connecticuts, South Dakotas, fractions of a Texas or fractions of an Alaska.
 * Our Dumb World, an atlas by the Onion, describes Rhode Island as being "roughly the size of one Rhode Island", which is to say: about 1/3 the size of Puerto Rico, or 76 times smaller than Portugal.
 * The CIA World Factbook describes the land area of every country in the world this way: "about half the size of Texas," "about the size of South Dakota" and in one or two cases "approximately three times as big as The Mall in Washington DC."
 * PJ O'Rourke once Lampshaded this trope, on a tour of a US Navy vessel, and came up with a few comparisons of his own, deciding for instance that the ship contained "enough rope to hang every Democrat elected to Congress since the Johnson administration."
 * For height, the preferred unit in the US is the Empire State Building. The Eiffel Tower is also used fairly often. For geologic height, it's Mt Everests.
 * British Newspapers prefer to include a range of comparisons to whatever the subject is, including a double-decker bus, Big Ben (St Stephen's Tower), St. Paul's Cathedral, Canary Wharf, The Eiffel Tower, the Empire State Building, the Petronas Towers and any other really famous skyscraper.
 * Mercilessly parodied by online British Newspaper The Register. Be warned that some of the examples listed may be Not Safe for Work
 * Mt. Everests occasionally appear as a unit of mass or weight. One science special declared that if all the mass in a single wooden matchstick were converted to energy, it would be enough to lift Mount Everest 20 feet off the ground.
 * Welsh comedian Rhod Gilbert has commented on BBC newsreaders' practice of describing areas of land as being the size of Wales:


 * Eohippus, the tiny ancestor of horses, is almost universally described as "about the size of a fox terrier". What makes this case particularly interesting is that this comparison is considerably more well-known than the size of a fox terrier itself, at least among paleontologists. Stephen Jay Gould wrote a lengthy article on the origin of this meme.
 * Similar to the above, it's common (mostly in documentaries) to compare the size of anything prehistoric with the size of a dinosaur. For instance, you typically won't get through a documentary talking about pliosaurs like Mosasaurus or Tylosaurus without having the narrator mention how it was "X times bigger than a T-Rex".
 * One measurement for caloric content is to compare foods to the equivalent number (or fractional number, as the case may be) of McDonalds Big Macs (540 calories, 27% of the average recommended daily caloric intake). Discussed in one Pv P strip, where Skull notes that even monsters do that (one plump Bavarian kid is apparently equivalent to 500 Big Macs).
 * A somewhat more peculiar measure: The Economist invented, and uses, a measurement called "The Big Mac Index" to compare currencies; since McDonalds is very strictly standardized, the price of a Big Mac directly corresponds to what it costs for the restaurant to serve it; as such, comparing the cost of a Big Mac to currency exchange rates can tell you when a currency is under- or over-valued.
 * Astronomers routinely measure the masses of stars and other heavy objects in increments of "solar masses". The masses of extrasolar planets are usually measured in increments of Jupiter masses or Earth masses.
 * Inverted. When the atomic bomb was first dropped on Hiroshima, Time magazine described it as seven times the power of the Halifax explosion.
 * A regular example at the Halifax memorial museum. The Halifax explosion is described as the biggest single explosion before Hiroshima.
 * The BBC (and other news sources) are noted for being fond of expressing measurements in terms of objects rather than any kind of units. In Britain these often include double-decker buses for length and football pitches for area, stepping up to 'the size of Wales' for larger areas, with slightly different ones being used in other countries. There's actually a fairly sensible reason for this, seeing as Britain has a somewhat peculiar relationship with the metric system; it's the only official system taught in schools, but businesses are perfectly entitled to use imperial ones for official purposes if they really want to and a surprising number still do. However, occasionally they throw in comparisons to things which surely the average person would have no idea about, such as "the volume of an Olympic swimming pool", "the size of a blue whale" and "the power of a Concorde".
 * Similarly, the CIA World Factbook expresses the size of every world country along the lines of "about the size of Texas" or "slightly smaller than Oregon" or occasionally "about twice the size of the Mall in Washington D.C." Justified, in that the CIA World Factbook is primarily written as a resource for US policy makers, and in any case the Factbook also gives the exact measurements in square kilometers.
 * Actually the World Factbook is mainly a public resource not a policy maker's resource, making the prioritizing of user-friendliness more understandable.
 * US news channels frequently give lengths and areas in terms of (American) football fields. They never specify whether or not they're including the end-zones, which is a significant difference, making this more confusing than clarifying.
 * The explosive power of very large explosions is measured in Hiroshimas, or occasionally in multiples of the sum total of all explosives used during World War Two.
 * Television meteorologists will give sizes of hail in much the same way, generally using sports equipment, usually ranging from golf ball-sized to softball-sized hail. One anecdotal case from the Ozarks had a person calling in about "cellphone sized hail" that had newscaster trying to guess whether they were thinking tiny flip-phones or huge Blackberries.
 * The Smoot, a measurement available in Google Earth.
 * Energy (or work, since it has the same SI dimensions) can be measured in Burning Libraries of Congress.
 * The stone-furlong-fortnight system (on the analogy of centimeter-gram-second and foot-pound-second) is an in-joke of science fiction fandom. If you are going to cling to "traditional" units, why not go ALL the way?
 * At the Millenium Philcon business meeting, a BNF who shall be nameless moved to amend an "X miles distance" clause to "2^10 furlongs". This was duly debated For: "It's fannish." Against: "It's stupid."