explain xkcd - User contributions [en]

426: Geohashing

2019-11-25T23:27:20Z

Arlo James Barnes: /* Trivia */ update

{{comic
| number = 426
| date = May 21, 2008
| title = Geohashing
| image = geohashing.png
| titletext = Saturday is game night
}}

==Explanation==
{{w|Geocaching}} is a sport where you have to find things hidden by other people based on geographical coordinates. Randall has had a similar idea before in [[201: Christmas GPS]].

[http://wiki.xkcd.com/geohashing/ Geohashing] is a sport created by Randall based on reaching a random location determined by an [http://wiki.xkcd.com/geohashing/Algorithm algorithm] that uses a {{w|hash function}} that involves the current date, location and the {{w|Dow Jones Industrial Average|Dow}} opening price. The Dow Jones Industrial Average is a {{w|stock market index}} dealt in New York City.

The algorithm is built in a way that:
*Makes it impossible to plan a meeting in advance - because of the Dow.
*Changes every day.
*Gathers people that are nearby - everyone within the same 1°×1° grid square gets the same position.

The algorithm works as follows:
# Take the current date in the format yyyy-mm-dd- and append the most recent opening value for the Dow Jones Industrial Average.
# Pass this string through the MD5 algorithm.
# Divide the hash value into two 16 character halves, and convert each half to a decimal.
# Take the integer portions of your current coordinates and append the decimal hash values.

{{w|MD5}} is a cryptographic hashing algorithm, and converts plaintext data into a seemingly random 128-bit (32 character) string. A good hashing algorithm should have three main properties: it is non-reversible and you cannot generate any plaintext data back from the hash, a given sample of data will always produce the same hash value, but even a tiny change to the original plaintext should produce an entirely different hash.

The example co-ordinates are for the Google headquarters in California, as you can see here: [https://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=37.421542+-122.085589&aq=&sll=37.0625,-95.677068&sspn=73.209607,135.263672&vpsrc=0&ie=UTF8&t=m&z=17&iwloc=A 37.421542 -122.085589]. The example date, May 26 2005, may reference the fact that the first edition of the Dow came out on May 26.

While geohashing was originally intended as a joke, there are people who geohash regularly. Please see the link to the xkcd wiki above.

The title text may imply that people should bring games to their geohashing location on the Saturday following the comic's release.

==Transcript==
:Date (example): 2005-05-26
:That date's (or most recent) DOW opening: 10458.68
:[Concatenate, with a hyphen: 2005-05-26-10458.68]
:md5: db9318c2259923d08b672cb305440f97
:[Split it up into two pieces:]
:0.db9318c2259923d0, 0.8b672cb305440f97
:To decimal: 0.857713..., 0.544544...
:Your location (example): 37.421542, -122.085589
:[Combine integer part of location with fractional part of hash:]
:Destination Coordinates: 37.857713, -122.544544
:Sample Implementation: <nowiki>http://xkcd.com/geohashing/</nowiki>

==Trivia==
* In response to comic [[353: Python]], the Python developers implemented the module <code>antigravity</code> in version 2.7+. This module contains a reference geohashing function.
* Due to the 2019 hacking of the XKCD forum server, which the Geohashing wiki was also hosted at, the wiki is unavailable until a more secure replacement is implemented.

{{comic discussion}}
[[Category:Comics with color]]

494: Secretary: Part 1

2016-11-20T03:16:53Z

Arlo James Barnes: /* Explanation */ Prez explication

{{comic
| number = 494
| date = October 27, 2008
| title = Secretary: Part 1
| image = secretary part 1.png
| titletext = The blueprints for the Department of the Internet offices call for Ceiling Cat-themed sprinkler heads.
}}

==Explanation==
The {{w|POTUS|President of the United States of America}} is the chief executive of the United States of America. Since this comic was released in October 2008 and the presidential election was in November, it was then unknown which of the candidates would become president by the time the comic was set (Spring 2009). This is why the president in the comic is out-of-panel and therefore not revealed to us. As it would turn out, the president inaugurated in January 2009 was Barack Obama, who has gone on to demonstrate a tactical use of the Internet (including the more frivolous aspects of it) for public relations purposes. The suppositional president in the comic is less savvy.

The tubes being clogged is a reference to the, now deceased, Alaska Senator {{w|Ted Stevens}} who, during a congressional debate on {{w|net neutrality}} described the {{w|Internet}} as a {{w|series of tubes}} (be sure to listen to the audio clips in that Wikipedia page, and you'll see why he became a big hit with the Internet). Ted Stevens also gained notoriety for backing a proposal to build a {{w|Gravina Island Bridge|bridge to nowhere}} using federal funds. The question "What are they a-Twitter about now?" refers to the website {{w|Twitter}}, which is a microblogging and social networking site.

Cats are notorious for being hard to herd, thus the idiom "herding cats" meaning an extremely difficult task that can very quickly get away from anyone undertaking it. {{w|Lolcats}} are pictures of cats, usually in humorous poses, that have insipid captions on them. The conflation of lolcats and the herding idiom escaped the president (who is presumably somebody not familiar with the former term). The title text refers to {{w|Lolcats#Ceiling Cat and Basement Cat|Ceiling Cat}}, a lolcat parody of God.

As with cats, Bloggers are an ideologically diverse bunch, and are hard to get to go in a single direction.

The proposed "Secretary of the Internet" would likely be a new position on the President's {{w|Cabinet of the United States|Cabinet}}, which currently consists of the heads of 15 executive departments and are, with the one exception of the Attorney General (who heads the Department of Justice), titled "Secretary of ''Department''".

All comics in the [[:Category:Secretary|Secretary]] series:
*494: Secretary: Part 1 (this one)
*[[495: Secretary: Part 2]]
*[[496: Secretary: Part 3]]
*[[497: Secretary: Part 4]]
*[[498: Secretary: Part 5]]

This series was released on 5 consecutive days (Monday-Friday) and not over the usual Monday/Wednesday/Friday schedule.

==Transcript==
:Spring 2009— The new president faces a crisis...
:[Cueball is talking to an unseen Mr. President, who is sitting behind a desk.]
:Cueball: Mr. President, the bloggers are restless.
:Mr. President: What are they a-twitter about now?

:Cueball: It's the tubes sir. They're clogged. We put too much stuff on them.

:Mr. President: How bad is it?
:Cueball: The internet could be inoperative within days.

:Cueball: We can't let a crucial resource go unshepherded.
:Mr. President: Go on.

:Cueball: I recommend you appoint a Secretary of the internet. Someone to impose some orders on this mess.

:Mr. President: Ordering bloggers around? Doesn't sound easy.
:Cueball: No; it's like herding lolcats.
:Mr. President: What?
:Cueball: Nothing.

:Mr. President: Do you have someone in mind for the post?
:Cueball: I know just the guy.

:Soon:
:Phone: ''Ring''
:[Black Hat looks away from his computer at the ringing phone.]

{{comic discussion}}

[[Category:Secretary|01]]
[[Category:Comics sharing name|Secretary]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Internet]]

Talk:1095: Crazy Straws

2012-08-15T10:06:35Z

Arlo James Barnes: Eliminated red link by creating page.

Compare [[915:_Connoisseur|xkcd.com/915]]. [[User:Arlo James Barnes|Arlo James Barnes]] ([[User talk:Arlo James Barnes|talk]]) 10:06, 15 August 2012 (UTC)