explain xkcd - User contributions [en]

1188: Bonding

2013-03-20T05:15:14Z

71.170.160.23: New comic

{{comic
| number = 1188
| date = March 20, 2013
| title = Bonding
| image = bonding.png
| titletext = I'm trying to build character, but Eclipse is really confusing.
}}

==Explanation==

==Transcript==

{{comic discussion}}

1184: Circumference Formula

2013-03-11T04:43:22Z

71.170.160.23: /* Explanation */ feet and inches

{{comic
| number = 1184
| date = March 10, 2013
| title = Circumference Formula
| image = circumference_formula.png
| titletext = Assume r' refers to the radius of Earth Prime, and r'<nowiki/>' means radius in inches.
}}

==Explanation==

The circumference of a circle is 2πr where r is the radius of the circle. Randall makes this note about r as a footnote, but this creates a typographical ambiguity, since the superscript 2 can also be an exponent. The formula now resembles πr2, which is the formula for the ''area'' of the circle.

In the title text, r' normally means the derivative of r, and r'<nowiki/>' the double derivative of r, whereas ' can also mean feet, while '<nowiki/>' can refer to inches.

==Transcript==
:Circumference of a circle:
:2πr2
:2The circle's radius

{{comic discussion}}

1179: ISO 8601

2013-02-27T08:49:51Z

71.170.160.23: /* Transcript */ "over" -> "written on top of"

{{comic
| number = 1179
| date = February 27, 2013
| title = ISO 8601
| image = iso_8601.png
| titletext = ISO 8601 was published on 06/05/88 and most recently amended on 12/01/04.
}}

==Explanation==
The two most commonly used date formats in the world are {{w|Date format by country|dd.mm.yyyy and mm/dd/yyyy}} (the symbols separating the values, as well as the year being 2 or 4 digits notwithstanding). This difference is often cause for debate. However, the comic explains that the International Organization for Standardization ({{w|ISO}}) has standardized dates in the yyyy-mm-dd format—this corresponds to neither of the aforementioned two formats.
The comic then lists many formats as "discouraged". This list starts with commonly used formats, which include the two above as well as other commonly used ones, such as dd/mm/yy. However the list then starts listing formats ranging from uncommon to absurd, such as writing the date partly in Roman numerals and painting the date in m/d/yy format with white paint onto a hissing black cat.

The title text mentions two dates in either the dd/mm/yy format or the mm/dd/yy format, but because the day values in both dates are less than 13, the format used is unclear.
(The standard was published on 5 June 1988 and amended on 1 December 2004.)

==Transcript==
Public Service Announcement:

Our different ways of writing dates as numbers can lead to online confusion. That's why in 1998 ISO set a global standard numeric date format. This is '''''the''''' correct way to write numeric dates:

2013-02-27

The following formats are therefore discouraged:
* 02/27/2013
* 02/27/13
* 27/02/2013
* 27/02/13
* 20130227
* 2013.02.27
* 27.02.13
* 27-02-13
* 2013. II. 27.
* 27⁄2-13
* 2013.158904109
* MMXII-II-XXVII
* MMXII [and] LVII [over] CCLXV
* 1330300800
* ((3+3)×(111+1)-1)×3/3-1/33
* 27 [''written on top of''] 02 [''written on top of''] 2013
* 10/11011/1101
* 02/27/20/13
* 0 [2,5] 1 [3] 2 [1,6,7] 3 [4] 7 [8]
* ''A cat, with the numerals'' 2-27-13 ''painted on it, going'' HISSSS

{{comic discussion}}