History Main / UnitConfusion

* In the ''Babylon 5'' episode "Messages from Earth", one spaceship evades another by hiding in the atmosphere of Jupiter. The pressure on the exterior of the ship as it descends is given in "gravities", although gravities are a measure of acceleration and not pressure.

* Confusion between Imperial and American Customary measurements is common as well. The two share the names of measurements, and lengths are the same value in both, but not volumes - pints and gallons for example. (An Imperial pint is 20 Imperial fluid ounces; a U.S. liquid pint is 16 U.S. fluid ounces. Similarly, an Imperial ton or "long ton" is 2210 pounds, but a U.S. ton or "short ton" is exactly 2000 pounds.)

* Confusion between Imperial and American Customary measurements is common as well. The two share the names of measurements, and lengths are the same value in both, but not volumes - pints and gallons for example. (An Imperial pint is 20 Imperial fluid ounces; a U.S. liquid pint is 16 U.S. fluid ounces.)

* Confusion between Imperial and American Customary measurements is common as well. The two share the names of measurements, and lengths are the same value in both, but not volumes - pints and gallons for example.

* In ''Film/Plan9FromOuterSpace'', one of the aliens says "Foolish humans, we have had space travel for eons of your light-years." An aeon being one billion years and a light-year being a measure of distance... (Then again, this is the same alien who said that "Particles of sunlight are many molecules in size.")

* In ''Film/Plan9FromOuterSpace'', one of the aliens says "Foolish humans, we have had space travel for eons of your light-years." An aeon being one billion years and a light-year being a measure of distance...

* In a book of ''TheScrameustache'', one Galaxian captain orders to reduce the speed by 2 parsecs.

* An infamous example occurs in the lawnmowing minigame in ''NoMoreHeroes'', where "square meter" has been [[CulturalTranslation culturally]] [[BlindIdiotTranslation "translated"]] into "acre" (roughly ''four thousand'' square meters).
** This was of course mercilessly parodied in the LetsPlay of the game. "You're a GIANT!"
* In the various incarnations of VideoGame/SimCity, each tile square is also supposed to be 1 acre. Yet a tile square is only big enough for a single one-family house with hardly any yard, and it takes 4 adjacent tile squares to build even a small apartment building. This could be hand-waved as just being a representation of an acre of homes, until you realize THE ROADS ARE AN ACRE WIDE (actually over 60 meters wide).

* In ''OnePiece'', after Usopp's "5 Ton" hammer is revealed to be a fake, Usopp admits that there is no way he can lift five tons when even five ''kilograms'' is too much for him. The 4kids dub changes this to him saying he is unable to lift five ''pounds''.

** Another related fallacy is the assumption that, for example, 40°C is twice as hot as 20°C. This is not true because 20°C is equal to 293.15K; twice as hot as this would be a lot more than 313.15°C (though not as much more as you might think; the relationship between heat and temperature is exponential rather than linear).

* ScroogeMcDuck has often boasted of his money bin storing "three cubic acres" of cash. An acre, of course, is a two-dimensional shape, and cubing it would create a geometrically-impossible ''six-dimensional'' shape. Although that would go a long way towards explaining just how all those countless billions fit inside that single building. [[note]]For the sake of completeness, what Carl Barks likely meant by this was that Scrooge's money bin consisted of three enormous cubes of cash, with each side of said cube defining an acre. The volume of this would be easy to calculate, if only an acre were not a ''rectangular'' shape. Oh dear...[[/note]]

** Another time, Jason decided to take up baking, and mused over whether the 350 degrees he had to set the oven at were in Celsius, Fahrenheit, or kelvins. [[hottip:*:For the record, 350 degrees Fahrenheit is a moderate oven temperature, 350 degrees Celsius is much higher than most ovens can go, and 350 kelvins isn't even hot enough to boil water.]] Peter sarcastically suggested that he rotate the oven almost a full circle. [[DontBeRidiculous "Don't be silly, Peter."]]

* ScroogeMcDuck has often boasted of his money bin storing "three cubic acres" of cash. An acre, of course, is a two-dimensional shape, and cubing it would create a geometrically-impossible ''six-dimensional'' shape. Although that would go a long way towards explaining just how all those countless billions fit inside that single building. [[hottip:*:For the sake of completeness, what Carl Barks likely meant by this was that Scrooge's money bin consisted of three enormous cubes of cash, with each side of said cube defining an acre. The volume of this would be easy to calculate, if only an acre were not a ''rectangular'' shape. Oh dear...]]

** Grampa Simpson hates the metric system. "My car gets forty rods to the hogshead, and that's the way I likes it!" [[hottip:*:If you're curious, that's approximately 120,000 liters per 100 km (0.002 miles per gallon). It must be a Hummer.]]

* Even unitless numbers can suffer from similar problems. In the US (and since a lot of other countries around the world have adopted the convention) a million is 10^6, a billion is 10^9, a trillion is 10^12, and so on. So the prefix n (latin for one, two, three etc) determines the number by 10^(3n+3). However in other countries that still use the old British/European system, a million is 10^6, a billion is 10^12, a trillion is 10^18, and so on (using the formula 10^6n). This is why scientist forgo using words and write large numbers in scientific notation instead.

[[folder:Western Animation]]
* In one episode of ''WesternAnimation/EdEddNEddy'', Edd is working on an old radio, and realizes he'd mistaken a "fifteen-amp resistor" for another part. The problem is, amps are used to measure ''current'', and the ''ohm'' is used to measure resistance. Resistors have power handling specifications too, but the unit for those is the watt, so that doesn't help.
* In ''WesternAnimation/TheSimpsons'', Crazy Vaclav asserts that the car he's trying to sell will "do 300 hectares on a single tank of kerosene". The hectare is a measure of area, not distance. Can be justified by the fact that Eastern European cars would be used for agricultural purposes and buyers would want to know how much of their fields they could cover per unit of fuel.
** Grampa Simpson hates the metric system. "My car gets forty rods to the hogshead, and that's the way I likes it!" [[hottip:*:If you're curious, that's approximately 120,000 liters per 100 km (0.002 miles per gallon). It must be a Hummer.]]
** Mr. Burns has trouble with metric too, like in the episode he drops a weight marked "1000 grams" (just over 2 lbs) on Homer, to his minor annoyance, and then comments that it sounded much heavier when he ordered it.
** In the episode where Bart goes to a gifted school, the kids con him out of his lunch by using units like picolitres to make it sound like they were offering more than they were.
** In the beginning in one episode where Homer takes the kids to school, he uses a GPS which gives him the distances in meters. The confusion leads him through a construction zone.
* In the ''FamilyGuy Star Wars'' movie ''Blue Harvest'', Han Solo (Peter Griffin) claimed that the Millennium Falcon completed the Kessel Run in less than 12 parsecs. Luke (Chris Griffin) then tells an astonished Han than parsecs are a measure of distance not time.
* In ''{{Transformers}}'', (well, some series, anyway) "light-year" has been a unit of time.
** ''Transformers'' has more [[http://tfwiki.net/wiki/Units_of_time units of time]] and [[http://tfwiki.net/wiki/Units_of_length distance]] than you can shake an exhaust pipe at. Most of them have never been explicitly defined, so any of them could be this trope.
* An in-universe example: in ''Jimbo and the Jet Set'', Jimbo's diminutive size is explained in the [[IncrediblyLamePun pilot]] episode as being the result of his designers mistakenly using centimetres instead of inches.
* The French version of ''WesternAnimation/{{Thumbelina}}'' (''Poucelina'') has the Prince singing [[http://www.youtube.com/watch?v=EKe5jzvUk8w "Depuis des années-lumière, je n'attends que toi."]] ("For light-years, I've been waiting for you.").
[[/folder]]

** Also, since all countries at least agree that a million is 10^6, sometimes larger numbers will go unused in favour of stating in millions. 10 thousand million million million is unambiguous, for instance, whereas while in the US and elsewhere it would be typically referred to as 10 sextillion, but some people in [[WithEuropeButNotAPartOfIt Britain and Europe]] would call that 10 thousand trillion (or in French possibly, 10 trilliard).

** That's because the mass-to-weight ratio is a constant on Earth (or close enough: on average g = 9.81 m/s^2) meaning there is a linear correlation between mass and weight. On Earth it pretty much means the same thing then. However, move to environments with a different gravity (basically any other planet or moon, although the correlation will be linear on that world) or even space (where weight becomes meaningless) and you get a different story. Even worse: if you launch the object from a planet and into space, the gravity exerted on the ship becomes variable (inverse square law) meaning the correlation between mass and weight is no longer linear.

-->--'''Boy in Brock's Gym''', ''VideoGame/PokemonRedAndBlue''

* In ''Plan9FromOuterSpace'', one of the aliens says "Foolish humans, we have had space travel for eons of your light-years." An aeon being one billion years and a light-year being a measure of distance...

* The most famous example of all: Han Solo bragging that his ship can make the Kessel Run in "less than twelve parsecs". Parsecs are a unit of distance, not time. While this has been {{Retcon}}-ned to death with constantly shifting backstories about skilled pilots shaving distance by flying close to black holes, even those omit that the Parallax Second is based on local (terrestrial) factors, specifically the radius of the Earth's orbit, and would have no meaning in "a galaxy far, far away".

** [[WordOfGod George himself]] gave an (awkward) explanation in the DVD Commentary. The Kessel Run is through a very nasty piece of space filled with all sorts of hazards. Lesser ships plot a longer but safer route. Because speed is a function of distance and time, you can decrease the time ''and'' the distance that it takes to travel between points by using a more powerful engine and more efficient computer that can plot a more direct route through hyperspace. Of course, this means Han's "more direct route" took him through over forty light-years. Of course, given that the Falcon flies at "light speed" if we are to believe Han Solo, this journey would take about 40 years to complete. I guess maybe Han's older than he looks.
*** This explanation is, with modifications, the one used in the [[StarWarsExpandedUniverse Expanded Universe]]; the major hazard is a black hole cluster near Kessel called the Maw, which a faster ship can travel closer to in hyperspace without getting pulled out.

*** Incidentally, this is the formula for a Schwarzchild radius (i.e. where a black hole's event horizon is). So a black hole with a mass equal to Earth's would be 9 mm in radius, or 18 mm across. As a quick approximation, a black hole's radius is 3 km for every Solar mass it has. A theoretical black hole with a mass equal to the mass of the observable universe would have a radius about equal to the radius of the observable universe.

** There is a joke where a woman is telling her friend about a guy's penis and claims it's 700 nanometers. The other woman is astonished that it's so small, but the first woman replies that the penis is that red (the wavelength of the color red is 620–750 nm).