526: Converting to Metric

Explain xkcd: It's 'cause you're dumb.
(Redirected from 526)
Jump to: navigation, search
Converting to Metric

[edit] Explanation

Most people will eventually develop an intuitive feel for how big certain measurements are (e.g., how long an inch or a foot is, how much a pound weighs). This comic points out that people who were brought up using the imperial system probably don't have the same intuitive understanding for metric units and attempts to provide some benchmarks for these people. Most of the benchmarks are common sense, highly-useful ones (e.g., if it's 30 degrees centigrade [86 °F], you'd be quite comfortable outside dressed for the beach) but some of the benchmarks are humorous and/or completely useless. Benchmarks include:

[edit] Temperature

  • Earth's hottest: 60⁠°C [140 °F]: The hottest temperature recorded on earth is actually "only" 56.7. There have been reports of ten-twenty degrees higher (70-80⁠°C) but these measurements are not verified or accepted as world records.
  • Various heat waves: Dubai is a city in the United Arab Emirates, and is smack-dab in the middle of an equatorial desert, so their heat waves can get hot!. The southern Unites States will typically be a few degrees hotter than the northern United States simply because it's closer to the equator, but as mentioned they're both above "Beach Weather".
  • 30°C [86 °F]: A little too hot so perfect for a trip to the beach.
  • 20°C [68 °F]: Is defined as room temperature in many experimental settings. For some this would feel a little cool. But 25°C [77°] would as mentioned be too warm for room temperature...
  • 10°C [50 °F]: Definitely wear a jacket. Especially if there is just a little breeze.
  • 0⁠°C [32 °F]: The freezing point of water (32°⁠F)
  • -5 to -10°C: In Moscow -10°C is not really that cold - it can go "spit goes clink" cold in Moscow, whereas -5°C [23 °F] in Boston may be very cold...
  • -20°C: FuckFuckFuckCold and -30°C - Fuuuuuuuuuuuuck!: This is implied to be basically what some people would say when they step outside at this temperature. In reality, it would be best to keep ones's mouth firmly closed. At -30°C, without taking wind chill into account, exposed skin will feel painful in under a minute and frostbite could begin in as little as ten minutes [1].
  • -40⁠°C: Spit goes "clink": As shown in the drawing your spit would freeze before it hits the ground. This is the crossing point of the two temperature scales i.e. -40°C = -40 °F.

[edit] Length

  • 1 cm [.4 inch] : Width of microSD card and 3 cm - Length of SD card: Refers to the memory cards used in cell phones, digital cameras, etc.
  • 12 cm [almost 5 inches]: CD-ROM is a common object so nice to know it is a dozen centimeters.
  • 14 cm [5 1/2 inches]: Most males would probably exaggerate the size of their penis, but 14–15 cm is very average.
  • 15 cm [almost 6 inches]: A Bic pen
  • 80 cm [31 1/2 inches]: A typical doorway is also of standard size. This is barely over the minimum size typically required by codes for buildings [30 inches or 76.2 cm], but more than 50% over the size required for aircraft emergency exits. (It may seem illogical that larger doors are required in buildings than in airplanes, given airplanes are arguably more dangerous. However, there is no real disadvantage to using larger doors in buildings, which are not significantly pressurized, but using larger doors in aircraft would increase the force on the door caused by cabin pressure proportionally.)
  • 1 m [39.37 inches]: Lightsaber blade: Refers the weapon used in the Star Wars movie franchise. Canonically, the length of a lightsaber's blade varies greatly depending on the setting of the weapon, but "one meter" is by no means a bad approximation.
  • 170 cm [5 feet, 7 inches]: Summer Glau: Refers to the height of the actress who portrays the character River Tam on the TV show Firefly.
  • 200 cm [6 feet, 6 and 3/4 inches]: Darth Vader: Refers to the height of the main antagonist from Star Wars.
  • 2.5 m [almost 10 feet]: Ceiling - of course very much depending on which type of building you are in!
  • 5 m [almost twenty feet]: Car length - also very much depending on the car...
  • 16 m 4 cm: Human tower of Serenity crew: Again, this refers to the Firefly TV show, which takes place mostly on a space ship called Serenity.
    • The other five members of the crew should also be stacked on top of these four to reach the 16m height - giving them an average height of 1.82 m (12 cm more than Summer Glaus height!)

[edit] Speed

Here both the SI unit m/s as well as the more used unit kph (km per hour) is given.
  • 5 kph [3 mph] - 1.5 m/s: Walking at a normal pace
  • 13-25 kph [8-15 mph]: Jogging to sprinting.
  • 35 kph [21.75 mph] - 10 m/s: Fastest human: As of 2009, the fastest a human has been recorded to run in a single sprint is actually 45 kph, a record set by Usain Bolt.
  • 45-55 kph: Both cats and rabbits go much faster than normal people.
  • 75 kph [46.6 mph] - 20 m/s: Raptor: It's a comic written by Randall, of course a reference to the velociraptors from Jurassic Park was going to be here.
  • 100 kph - 25 m/s: A slow highway (62 mph).
  • 110 kph [68.35 mph] - 30 m/s: Interstate (65 mph): Refers to the American highway system. (65 mph would actually be only 104.6 kph.)
  • 120 kph - 35 m/s: Speed you actually go when it says "65": People routinely break the aforementioned speed limit, and the police typically don't mind as long as it's not posing any danger. For the record, 120 kph is 74 mph.
  • 140 kph - 40 m/s: Raptor on hoverboard: The hoverboard is probably a reference to the Back to the Future Part II, though it's a fairly common trope in older science fiction stories. Randall obviously did a lot of google searching on this subject the week before - see 522: Google Trends.

[edit] Volume

  • 3 ml: The amount of blood in a fieldmouse. A similar amount is used in comic 434: xkcd Goes to the Airport, but instead of a fieldmouse, the measurement of blood is of a churchmouse, an imaginary animal created by Lewis Carroll. Click here for a more on comic 434.
  • 5 ml: A teaspoon - a very common measure.
  • 30 mL: Nasal passages and 40mL - Shot glass: The comic points out that you could just about fill a shot glass using the mucus from your nose. Since shot glasses are usually used for mixed drinks, the comic jokes that this mucus could constitute a new, disgusting drink - and this is depictured in the drawing.
  • 350 ml: Soda can (this is roughly correct for the cans used in the U.S., which hold 12 fluid ounces; in Europe, soda cans commonly hold 330ml or 500 ml).
  • 500 ml: Water bottle (this is the also the volume of a European water bottle).
  • 3 L: Two-liter bottle: Refers to a bottle which contains two liters (in the US usually soda). There is debate as to the reason for the discrepancy in volume.
  • 55 L: Summer Glau: Again, this refers to the actress from Firefly.
  • 65 L: Dennis Kucinich: An American politician belonging to the Democratic party, noted for his relatively strong (for the US) leftist views.
  • 75 L: Ron Paul: An American politician belonging to the rival Republican party, noted for his strong rightist views.
  • 200 L: Volume of refrigerator.
  • As shown in the drawing of this part of the comic, the three persons mentioned above - Glau, Kucinich and Paul (summing up to 195 L) - could in principle all fit inside a standard refrigerator. Cueball thus attempts to push them all inside of one - though it would obviously be very uncomfortable for all parties involved to be trapped in such a small space with not much room between them.

[edit] Mass

  • 3 g: Peanut M&M: A small chocolate candy with a peanut inside
  • 100 g: Cell phone - this very much depends on the age of the cell phone, and the type etc.
  • 500 g [1 lb.]: A bottle of water contains 500 ml according to the volume section and thus have mass of 500 g.
  • 1–3 kg: Different types of laptops. The newest and the best is the lightest...
  • 5 kg [11 lb.]: LCD monitor: A modern flat-screen-style monitor.
  • 15 kg: CRT monitor: An older-style, cathode ray tube-based monitor.
  • 60 kg [130 lb.]: Lady - for instance if she is Summer Glau - could be her again depicted in the comic - average weight of an adult woman.
  • 70 kg [150 lb.]: Dude - here depicted as Cueball who is the average guy, and 70 kg is average weight for an adult man.
  • 150 kg: Shaq: Shaquille O'Neal, a famously tall basketball player.
  • 200 kg [440 lb.]: Your mom
  • 220 kg: Your mom (incl. 20 kg of cheap jewelry) and
  • 223 kg: Your mom (also incl. 3 kg of makeup)
  • These last refers to a common type of Your mom joking insult whereby someone insults someone else's mother in a creative way. Here, the comic slyly calls your mom fat, then implies she wears way too much jewelry and finally also almost 7 pounds of makeup. This is a common theme in xkcd. (Twenty kg of "cheap" jewelry has several times the volume than 20 kg of gold jewelry, because of the difference in density.)

[edit] Title text


[edit] Transcript

Guide to Converting to Metric

The key to converting to metric is establishing
"that's warmer than a house but cool for swimming."
Here are some helpful tables of reference points:

[The frame to the left of the above text:]
60°C Earth's hottest
45°C Dubai heat wave
40°C Southern US heat wave
35°C Northern US heat wave
30°C Beach weather
25°C Warm room
20°C Room temperature
10°C Jacket weather
0°C Snow!
-5°C Cold day (Boston)
-10°C Cold day (Moscow)
-20°C Fuckfuckfuckcold
-30°C Fuuuuuuuuuuck!
-40°C Spit goes "clink"
Cueball: Ptoo
Spit: Clink!

[The frame to the right of the above text:]
1 cm Width of microSD card
3 cm Length of SD card
12 cm CD diameter
14 cm Penis
15 cm BIC pen
80 cm Doorway width
1 m Lightsaber blade
170 cm Summer Glau
200 cm Darth Vader
2.5 m Ceiling
5 m Car-length
16 m 4 cm Human tower of Serenity crew

[The frame below to the left:]
kph m/s
5 1.5 Walking
13 3.5 Jogging
25 7 Sprinting
35 10 Fastest human
45 13 Housecat
55 15 Rabbit
75 20 Raptor
100 25 Slow highway
110 30 Interstate (65 mph)
120 35 Speed you actually go when it says “65”
140 40 Raptor on hoverboard

[The frame below in the middle:]
3 mL Blood in a fieldmouse
5 mL Teaspoon
30 mL Nasal passages
40 mL Shot glass
350 mL Soda can
500 mL Water bottle
3 L Two-liter bottle
5 L Blood in a human male
30 L Milk crate
55 L Summer Glau
65 L Dennis Kucinich
75 L Ron Paul
200 L Fridge
So, when it's blocked
the mucus in your
nose could about
fill a shot glass.
Related: I've
invented the
worst mixed
drink ever.

[The frame below to the right:]
3 g Peanut M&M
100 g Cell phone
500 g Bottled water
1 kg Ultraportable laptop
2 kg Light-medium laptop
3 kg Heavy laptop
5 kg LCD monitor
15 kg CRT monitor
4 kg Cat
4.1 kg Cat (with caption)
60 kg Lady
70 kg Dude
150 kg Shaq
200 kg Your mom
220 kg Your mom (incl. cheap jewelry)
223 kg Your mom (also incl. makeup)
Cat (with caption): Mrowl?
















Personal tools


