# Difference between revisions of "Talk:2170: Coordinate Precision"

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Also the table at https://en.wikipedia.org/wiki/Decimal_degrees is similar to the comic, and predates it by at least a year. Not sure how or if that should be included in the explanation.[[Special:Contributions/172.68.58.149|172.68.58.149]] 23:53, 4 July 2019 (UTC) | Also the table at https://en.wikipedia.org/wiki/Decimal_degrees is similar to the comic, and predates it by at least a year. Not sure how or if that should be included in the explanation.[[Special:Contributions/172.68.58.149|172.68.58.149]] 23:53, 4 July 2019 (UTC) | ||

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+ | Then of course there's N 47° 38.938 W 122° 20.887 - You're probably a [[wikipedia:Geocaching|geocacher]] (Which always uses the GPS standard WGS84 datum, by the way, so that's that problem solved). --[[User:IByte|IByte]] ([[User talk:IByte|talk]]) 11:37, 6 July 2019 (UTC) |

## Revision as of 11:37, 6 July 2019

The coordinates seem to show a NASA building, so in the end you're still soing something space related. 172.69.55.196 19:47, 1 July 2019 (UTC)Some random European.

- The more precise coordinates are actually in the middle of the Rocket Garden at the Visitor's Center of the Kennedy Space Center complex. Ianrbibtitlht (talk) 19:58, 1 July 2019 (UTC)

The atom-level coordinates are obtained by appending digits of e and pi to the Rocket Garden coordinates. Ichoran (talk) 20:21, 1 July 2019 (UTC)

I always find it very funny to see all those decimals. Regular GPS devices have an uncertainty of 3 meters if there is no interference from trees, buildings or whatever. That puts you at about 4 to 5 decimals I guess. Palmpje (talk) 20:26, 1 July 2019 (UTC)

- A Google Maps webpage URL includes coordinates to seven decimal places. EmuSam (talk) 20:48, 1 July 2019 (UTC)

So combining this comic with #2169, is Randal suggesting he'll be at the Rocket Garden on July 28th (much as he did in #240)? 108.162.216.208 20:47, 1 July 2019 (UTC)

- It says
*June*28th. --162.158.126.22 20:52, 1 July 2019 (UTC)- No, the date of that comic is June 28, but the title text says: [AT THE JULY 28TH MEETING] --Kynde (talk) 21:51, 1 July 2019 (UTC)
- Ah, that makes sense. For some reason my app only showed the first part of the tirle text --162.158.126.94 23:04, 1 July 2019 (UTC)

- No, the date of that comic is June 28, but the title text says: [AT THE JULY 28TH MEETING] --Kynde (talk) 21:51, 1 July 2019 (UTC)

Regrettably, there are two dimensions missing, Z and T. Without Z (elevation)+/- you could be in space or in a neutrino detector. T is only relevant for dynamic objects, but there again, the Americas are going West at a measurable rate! RIIW - Ponder it (talk) 21:30, 1 July 2019 (UTC)

The seventh row is likely a reference to comic number 1358 where two stick figures try to find waldo via satellite. 172.69.226.125 21:44, 1 July 2019 (UTC) kisara, 21:42, 1 July 2019 (utc)

10^-40 degrees on the surface of the earth translates to about 0.7 planck lengths. 162.158.106.234 21:50, 1 July 2019 (UTC)

Do the coordinates 28.5234°N, 80.6830°W really correspond to the tip of the Delta rocket? I checked and it was pointing to a small patch of ground next to the rocket, not the tip of the rocket itself. Herobrine (talk) 00:20, 2 July 2019 (UTC)

- No, you need to go to five decimal places to get the rocket. In that respect, I think he might be off by one digit of precision in his descriptions. Jeremyp (talk) 12:04, 2 July 2019 (UTC)

I would like to mention that neither number seems to fit into a standard double float value. I made a fiddle showing this. [1] Ansarya (talk) 01:48, 2 July 2019 (UTC)

- Floats are stored base 2, so representing them exactly as decimal often requires many more digits than is actually necessary (for complicated number theory reasons, a float can always be represented exactly as decimal, which would not be true if floats were stored in base 3). For this reason, programming languages that can format floats round them, usually to a number of digits where it will be possible to reconstruct the original float (though C# apparently takes off a couple extra digits, since those digits are almost never significant). To illustrate this, I used Rust to print many more digits of a float than would be shown normally [2]. The latitude coordinate in the comic could be the result of printing a double precision float, but the longitude coordinate could not be. Also note that it takes almost 50 digits to reach an exact base 10 representation, even though only 14 or 15 of those digits are actually needed to reconstruct the original float. Probably not Douglas Hofstadter (talk) 18:01, 2 July 2019 (UTC)

May be my pet peeve... ...but adding an additional error to every piece of input data [and maybe every intermediate result] in order to show that either the precision the original measurement ends here or that all further digits of the measurement read "0" often introduces an error that can add up surprisingly quickly => I personally prefer raw floats that indicate there probably was no error analysis to rounded data and won't get tired on telling people to explicitely state what precision they can expect.162.158.114.70

If the smallest subnormal 32 bit float is a Planck length, then the largest 32 bit float is 10 sextillion times the diameter of the observable universe. If the value 1.0 of a 64 bit float is a cubic Planck length, then the largest float is 100 sextillion *googol* times the volume of the observable universe. Probably not Douglas Hofstadter (talk) 17:21, 2 July 2019 (UTC)

It'd be neat to have a map that shows the precision of given coordinates; like how Google Maps shows transparent blue circle with a wider radius if it's location detection isn't very precise. 172.69.170.76 19:10, 2 July 2019 (UTC)

Something about the formatting of the table seems to be messing up the main page. Not sure what it is, but it happens just after the '110 km (70 mi)' so might be related to the span. Not a major problem as it's fine on the comic page and the main page will change tomorrow anyway. AlChemist (talk) 19:43, 2 July 2019 (UTC)

/\ / \ /____\

information is people 172.68.34.172 01:27, 3 July 2019 (UTC)

"more than a quintillion times smaller" that's short scale quintillion, right? Kventin (talk) 08:04, 3 July 2019 (UTC)

- ...and it's ambiguous otherwise. Depends entirely upon what one understands as "one time smaller" (or even if you can have a meaningful "zero times smaller", if you prefer) before you start to further multiply the smallerness by incrementing the factorisation. 141.101.98.76 00:57, 6 July 2019 (UTC)

This is probably a reference to the fact that persons are animate, and different persons can occupy the same position at different times.

No it is not. The comic itself explicitly states that it's a reference to the geodetic datum when it says, but since you didn't include datum information, we can't tell who

.

As the comic notes, different persons can occupy the same position at different times

. Where does it note that? Am I looking at a different comic? 162.158.38.166 09:57, 3 July 2019 (UTC)

Is there supposed to be a comma after the dash in the description on 15 decimal places? I thought the "beginning - interjection - end of sentence" structure doesn't require a comma since the interjected section is basically a comma in itself. 172.69.44.146 16:51, 3 July 2019 (UTC)

- As I learned it, a sentence with an interjection should be structured and punctuated as if the interjection were not there, be it enclosed in parentheses or dashes. See “Let's hunt – and then eat –, Grandma!”. 172.68.226.106 22:40, 3 July 2019 (UTC)

For whatever reason, the plural of “geodetic datum” is “geodetic datums”. If you say “geodetic data”, then that sounds like you’re talking about a list of coordinates or something. It’s not regular, but it’s standard usage in the geodetic field. 172.69.160.150 13:47, 4 July 2019 (UTC)

"The coordinates at 28.52345°N, 80.68309°W (in decimal degrees form; in geographic coordinate system form using degrees, minutes, and seconds, 28° 31′ 24.24.4″N, 80° 40′ 59.1″W)". The reference https://en.wikipedia.org/wiki/Geographic_coordinate_system does not support the view that degrees-minutes-seconds are any more of a geographic coordinate system than are decimal degrees (or meters, radians, etc. for that matter). This reads like somebody is grinding an axe.172.68.58.149 23:53, 4 July 2019 (UTC)

Also the table at https://en.wikipedia.org/wiki/Decimal_degrees is similar to the comic, and predates it by at least a year. Not sure how or if that should be included in the explanation.172.68.58.149 23:53, 4 July 2019 (UTC)

Then of course there's N 47° 38.938 W 122° 20.887 - You're probably a geocacher (Which always uses the GPS standard WGS84 datum, by the way, so that's that problem solved). --IByte (talk) 11:37, 6 July 2019 (UTC)