Editing 2888: US Survey Foot

{{comic
| number    = 2888
| date      = January 31, 2024
| title     = US Survey Foot
| image     = us_survey_foot_2x.png
| imagesize = 740x606px
| noexpand  = true
| titletext = Subway refuses to answer my questions about whether it's an International Footlong or a US Survey Footlong. A milligram of sandwich is at stake!
}}

==Explanation==
{{incomplete|Created by a VERY SHORT 84 FEET - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic pokes fun at the difference in length between the {{w|Foot_(unit)#U.S._survey_foot|US Survey Foot}} and the {{w|Foot_(unit)|International Foot}}. After Carl Edvard Johansson's {{w|Carl_Edvard_Johansson#Johansson_and_the_inch|gauge blocks}} in 1912 led to {{w|International_yard_and_pound|an international agreement}} in 1959, the foot has been defined to be exactly 0.3048 metres, whilst the US survey foot continued to use the {{w|Mendenhall Order|definition of 1893}}, making it a bit longer than the international foot at 1200/3937 meters. However, the difference between the two is proportionately too small to be meaningful for most purposes, as they only differ by 2 parts per million. At foot-length scales, the difference is a fraction of a micron, with longer measures (where the error grows to a notable degree) requiring an already excessive implied precision likely to mismatch its true accuracy. Some engineering or scientific applications ''may'' involve such tolerances, but would be expected to consistently use some more modern standard of measurement to {{w|Mars Climate Orbiter|avoid such confusion}}.

In the third panel, Cueball says that someone is using the survey foot again: it turns out to be [[Black Hat]], an action that sounds very typical for him. Cueball claims that he is drawing the world 610nm closer to madness, which is about the difference between the two measures (per foot). Cueball, outraged, then says that the {{w|National Institute of Standards and Technology}} (usually abbreviated as NIST) will capture Black Hat to stop him from using the US survey foot. The joke here is that his coordinates show that he is 8,000 miles away, but since he is using the US survey foot, he is 0.016 miles away from the search team, making them unable to find him at that exact spot. (A good strike team would likely keep looking, but perhaps being strictly NIST-trained to adhere to particularly exacting standards has ironically made them vulnerable to the same inaccuracies that they are supposed to be preventing.)

Note – 0.016 miles is about 28.16 yards (84.48 feet), or 84.4798 US Survey Feet, or 25.749 metres; they are shown as probably being at the same lake in the last two frames, with maybe little more than a frame border between them.

Part of the joke is the imaginative idea that NIST employs and dispatches strike teams to apprehend persons that use incorrect measurements. This may be a play on words about the {{w|Nuclear Emergency Support Team}}, or "NEST", a {{w|United States Department of Energy}} group who respond to nuclear and radiological emergencies such as reactor accidents or nuclear terrorism, and who might reasonably have access to resources such as the helicopters depicted during a crisis.

The title text references a {{w|Subway (restaurant)#Sandwich_size|2013 lawsuit}} over the length of a "Footlong" sandwich sold by Subway fast food chain. However – in contrast to the issue at stake in that lawsuit – the difference in length between an 'international footlong' sandwich and a 'US survey footlong' sandwich is way below the precision ''or'' accuracy by which sandwiches are usually produced – making it understandable that Subway would not think it necessary to clarify which definition of 'foot' they use for their products.

===Explanation of the comic's underlying assumptions and implications===
Randall appears to be playing a bit fast-and-loose here. To make this joke work implies a rather absurd situation: that both Black Hat and the searchers have set their devices to measure and report location ''in reference to'' the same location (the place where Cueball is and that is at one end of the 8,000 mile measurement) and not just use GPS and lat/long like every other smartphone on the planet. 

The only origin location that can be reasonably inferred based on the comic's info is NIST headquarters in Gaithersburg, Maryland. 

In the unlikely event that the searchers' phones measure and report location in reference to NIST HQ, evidently Black Hat has also overridden his device's in-built GPS to report its location in reference to NIST headquarters as a way to toy with them and then traveled EXACTLY 8,000 miles away, knowing NIST would be in hot pursuit. After all, Black Hat is known for his preternatural powers of mischief. 

Where might Black Hat be hiding? If he was in U.S. territory that would give them clear jurisdiction over him, but there is no U.S. territory which is [https://www.mapdevelopers.com/draw-circle-tool.php?circles=%5B%5B12874687.81%2C39.1450494%2C-77.2161307%2C%22%23AAAAAA%22%2C%22%23000000%22%2C0%5D%5D exactly 8,000 miles from NIST headquarters in Gaithersburg, Maryland] (regardless of which foot is used). The closest U.S. territory would probably be Cocos Island, Guam, 7923.92 miles away from Gaithersburg; the closest U.S. jurisdiction is probably the U.S. Embassy in Dhaka, Bangladesh, at 8015.14 miles. This implies that Black Hat is not on U.S. soil, which means that the NIST strike team is operating in a legal gray area, like a SEAL team catching an international terrorist.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Closeup on Cueball.]
:Cueball: We thought it was over. After 60 years of struggle, the US survey foot was dead, deprecated by NIST in 2023.

:[Cueball is shown to be talking to Ponytail, Hairy, and Megan. He has a presentation behind him.]
:Cueball: We thought architects and engineers could rest easy, free of the headaches of having two conflicting definitions of the foot that differ by 610 nanometers.
:International foot: 0.304 800 000 m
:US survey foot [crossed over in gray] <span style="color:gray">R.I.P.</span>: 0.304 800 609... m

:[Cueball points at an image of Black Hat]
:Cueball: But I bring dire news:
:Cueball: ''Someone has started using the US survey foot again.''

:[Closeup on Cueball again.]
:Off-panel voice: Why!?
:Cueball: We don't know.
:Cueball: Some people just want to drag the world 610nm closer to madness.

:[Farther view of Cueball only. He clenches a fist.]
:Off-panel voice: What can we do!?
:Cueball: A NIST team is already in the air. We will capture the scofflaw and end this nightmare.

:[Two helicopters flying, with mountains in the background.]

:Caption: 8,000 miles away
:[Two operatives in a forest by a pond with "NIST" helmets. One talks on a walkie-talkie.]
:Operative: We've reached the coordinates of the target's device. There's no one here.
:Voice from walkie-talkie: How!?

:Caption: 8,000.016 miles away
:[Black Hat walking elsewhere (by the same pond) in the forest, very close by.]
:Black Hat: ♫ ♪

==Trivia==

The number of miles in the last panel was [https://www.explainxkcd.com/wiki/images/archive/5/5f/20240131173446%21us_survey_foot_2x.png originally] 8,000.014, but was changed to 8,000.016. The latter matches the 2 ppm difference between the international foot and the US survey foot.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Black Hat]]
[[Category:Characters with hats]]
[[Category:Geography]]
[[Category:Food]]