2153: Effects of High Altitude

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Effects of High Altitude
If she'd lived in Flagstaff (elevation 6,903 feet), Cruella de Vil would only have needed 89 dalmatians for her coat.
Title text: If she'd lived in Flagstaff (elevation 6,903 feet), Cruella de Vil would only have needed 89 dalmatians for her coat.


This comic starts out with three effects of high altitude related to the air getting "thinner" and the lower air pressure. Denver is one mile (5280 feet or 1609 meters) above sea-level (as marked on the steps of the State Capitol). At this elevation, the average atmospheric pressure is about 83% of sea level pressure, or about 840 mbar instead of 1013 mbar, and gravity is 99.94% of gravity at sea level at the same latitude, or 9.796 m/s2 instead of 9.801 m/s2. This has a number of effects:

  • Water boils at 202 degrees F (94 degrees C), slightly lower than the baseline 212 degrees F (100 degrees C) it takes at sea level.
  • Baseballs and golf balls fly slightly farther (with the same initial velocity, the distance is inversely proportional to gravitational acceleration so it would be 0.06% farther; in addition, the lower air pressure will reduce the resistance from the air the ball will experience, therefore it will slow down at a lower rate and thus fly even farther than the 0.06% due to gravity).
  • Sunburn develops faster because there is less atmosphere above to filter out harmful ultraviolet rays.

As usual for xkcd, the effects of high altitude are extended in a comically absurd manner, applying this "slightly less" rule to things that have nothing to do with altitude:

  • Scrabble is a board game where each letter is assigned a point value based on its frequency of use in the edition's language. The comic claims all letters are worth 16% more. When applied to the normal values for the Scrabble tiles in English
    • Q is worth 12 instead of 10
    • X is worth 9 instead of 8
    • Y is worth 5 instead of 4

This point increase would have little impact in the board game when two players sit across each other. However, it would imply that scrabble played via internet should require players to state their altitude at the beginning of the online game which then assigns advantages to higher-altitude players. This advantage seems arbitrary, unless the altitude difference is really significant enough to impede the thinking ability of the higher-altitude party.

  • A common superstition states that breaking a mirror causes 7 years of bad luck. The comic claims that at higher altitudes, only 5½ years are caused. This implies that people living at higher altitudes have less bad luck.
  • Marketing campaigns will often state "X is the new Y" to draw the audience of Y in toward the newer X. When used with age, usually at 10 year intervals ("40 is the new 30" is the slogan referenced), it is an attempt to convince an older audience that they can share in an experience commonly associated with a younger audience. At higher elevations, the comic claims, people can use or do things designated for an even younger audience. This is contrary to facts however: Most activities, especially in sports, are more difficult at higher altitudes, not easier.
  • German band Nena's hit 99 Red Balloons (an English adaptation of the original song called 99 Luftballons) is a song about a war started by a large clump of balloons mistaken for enemy aircraft (see #Trivia). The comic claims that if launched from a higher altitude, 94 balloons would have sufficed.
  • 4:20 is a code word for cannabis and has evolved in some circles to be the socially acceptable hour to consume cannabis. This has in turn evolved into a joke that when checking the time and finding it is exactly 4:20, people will add "blaze it" as a reference. The comic claims that, at higher altitudes, the socially acceptable time is earlier, so if there is an elevation of one mile, the socially acceptable time would be 4:17 and therefore, marijuana jokes are made earlier. This joke is probably related to the legalization of recreational marijuana use in Colorado.

In the title text, One Hundred and One Dalmatians is a Disney franchise (based on a children's book), where the villain, Cruella de Vil, aims to capture and kill 99 Dalmatian puppies (97 in the book) to have the perfect spotted fur coat. (The title includes the parents [book: and other Dalmatian caregivers] of the Dalmatian puppies.) The comic claims that, at a higher altitude in Flagstaff (6903 ft / 2104 m), she would only have needed 89 Dalmatians, possibly implying that puppies at higher altitudes are bigger (perhaps because there is less air pressure to compress them) or that Cruella de Vil at high altitudes is smaller (possibly because of the higher humidity and lower temperature).


Effects of High Altitude
How life is different at one mile above sea level
(e.g. in Denver)
[Eight small panels, each containing an image with a caption at the top:]
[A pot on a stovetop, with steam rising from the pot]
Water boils at 202°F
[A baseball flying through the air]
Baseballs and golf balls fly 5-10% farther
[Five wavy arrows hitting a curved surface, two at a low point and three at a high point]
Sunburns develop significantly faster
[Scrabble tiles for letters Q, X and Y with point values 12, 9 and 5, respectively]
Scrabble letters are worth 16% more
[Cueball looking down at a broken hand mirror on the floor]
Breaking a mirror only causes 5½ years of bad luck
[Cueball and Megan are talking. Megan is gesturing]
40 is the new 28
Megan: 50 is the new 40, and when you account for elevation it's more like 37.
[Five black balloons floating]
Nuclear war can be started with only 94 red balloons.
[Cueball and Ponytail are talking. Ponytail is looking at her phone]
People make marijuana jokes slightly earlier
Cueball: Hey, what time is it?
Ponytail: 4:17 Blaze it!


  • A similar effect on sports caused by different latitudes was the topic of 852: Local g.
  • 99 Red Balloons is generally assumed to mean a UFO starts a nuclear war, but the craft is not necessarily a flying saucer nor is the war necessarily nuclear. Although the original German song refers to "UFOs aus dem All", the lyrics of the English-language song say "There's something here from somewhere else" which does not imply extraterrestrial origins, merely that the object is not of domestic origin; and "the war machine springs to life", which implies that a rival nation on earth is thought to be the culprit.



I don’t even know where to begin. “That Guy from the Netherlands” (talk) 18:00, 22 May 2019 (UTC)

Is that because in the netherlands you do not have any experience with the effects of high altitude? --Lupo (talk) 08:10, 23 May 2019 (UTC)

Can anyone verify if the baseballs and golf balls actually fly further? I'd assume it's due to lower air density and therefore resistance, not weaker gravity as someone else had written. Cgrimes85 (talk) 18:13, 22 May 2019 (UTC)

Both parts (air resistance and gravity) play a role here. 18:17, 22 May 2019 (UTC)
At 1 mile altitude the acceleration due to gravity is only about 0.05% less than at sea level, so I don't think it's important relative to the lower air resistance. Cgrimes85 (talk) 18:53, 22 May 2019 (UTC)
The difference in gravity due to being 1 mile farther away from the center of the earth is negligible and due to having more mass(aka mountains) under them Denver actually has a slightly higher Local Gravitational Acceleration at 9.81112m/s^2 than say Los Angeles at 9.80636m/s^2. wolfram alpha source Decreased air resistance is the reason for flying further. Stickfigurefan (talk) 19:21, 22 May 2019 (UTC)
Note however that the spin-induced lift would be lower in the thinner air which would somewhat counteract the reduced gravity and air drag. 12:40, 23 May 2019 (UTC)
This is a fairly commonly recognized phenomenon. Many golf publications reference this. e.g. Titleist postOhFFS (talk) 21:20, 22 May 2019 (UTC)
This is also commonly recognized in baseball. For example, [this paper[1] argues that after the spin-induced lift reduction ball will still fly 5% farther in Denver than in Boston due to altitude. 14:08, 23 May 2019 (UTC)
Considering the negligible effect of gravity on balls distances (and boiling temperatures and sunburns for that matter), should we not just remove any references to gravity from the main explanation? 09:34, 24 May 2019 (UTC)

I'd say the last frame is a reference to 5 o'clock time for drinks. On urban dictionary there's a reference to 4:20 being the time to 'smoke the reefer' Palmpje (talk) 18:17, 22 May 2019 (UTC)

It's definitely about weed, not liquor. See Wikipedia article on 420. Barmar (talk) 18:36, 22 May 2019 (UTC)
The frame says it's about marijuana. How is this one in question? OhFFS (talk) 21:21, 22 May 2019 (UTC)

Although the comic relates to nuclear war neither the original German text nor the English reworked text (it's definitely not a direct translation) refer to nuclear war. Both refer to unidentified objects however so I've adapted the explanation to that end. Palmpje (talk) 19:18, 22 May 2019 (UTC)

There appears to be some debate around the UFOs. In my opinion the original German text should prevail (I'm Dutch, not German). The original lyrics state "hielt man für UFO's aus dem All"

which means "thought they were UFOs from space". The English lyrics are not that definite. Anyway - a large 99 (or is it 94 at altitude?) year war broke out just because of some hyper-tense generals. Palmpje (talk) 19:45, 22 May 2019 (UTC)

The comic refers to "red" balloons, which which are only present in the English version. The original German text doesn't mention the color of the "Luftballons", so it's not so obvious that this version should prevail. 13:47, 23 May 2019 (UTC)

Re: Nena: Currently listening to the English version. It does stick out somewhat that it is about "99 RED Baloons" -- Red Scare possibly involved in the translation? Also, both versions refer to Cptn. Kirk, who is infamous for his rather aggressive negotiation-techniques. sba

The "420" mile marker on Interstate 70 in Colorado was replaced by a "419.99" marker because it kept getting stolen. [2]. Probably not Douglas Hofstadter (talk) 14:46, 23 May 2019 (UTC)

Re: 101 Dalmatians: in the book there are 97 puppies and 4 adults (Pongo, Missis, Perdita and Prince), simplified in the film to 99 + 2. 13:16, 24 May 2019 (UTC)

I noticed that, too, and fixed it with some parentheticals. I've noticed such level of detail is normal in these explanations. Trlkly (talk) 04:41, 26 May 2019 (UTC)


The Scrabble tiles' new scores aren't 16% higher. 4 > 5 is +25%, 8 > 9 is +12.5%, 10 > 12 is +20%. It seems that Randall rounded to the nearest whole number. These Are Not The Comments You Are Looking For (talk) 05:20, 27 May 2019 (UTC)