explain xkcd - User contributions [en]

Talk:1306: Sigil Cycle

2013-12-20T22:21:51Z

108.162.219.227:

Shouldn't it be QBASIC$ (or QBASIC%), since in Basic the sigil is attached to the end of variable names? --[[Special:Contributions/173.245.53.108|173.245.53.108]] 13:19, 20 December 2013 (UTC)

Could not find where categories can be added, here's a list of suitable categories: Charts, Computers, Comics presenting a compromise Internet, Programming [[Special:Contributions/173.245.53.180|173.245.53.180]] 13:32, 20 December 2013 (UTC)

This comic de-emphasizes the value of sigils. It's very ironic that Randall chose C++, a language with symbols, to exemplify plain words. And C is a reason for not naming technologies after letters. Same with X. You have to search for "C programming language" or "X window system." It's very helpful to distinguish things with unique sigils, especially in this current age where we depend on full-text search. Just look at my login ID, tbc. I have been tbc on the Internet since 1981. But I eventually had to go by tbc0 (e.g. on Twitter) because tbc isn't unique enough. Google was named after 10^100 (an incomprehensibly large number reflecting their ambition). But that number is spelled googol. They own their spelling. Brilliant. Consider examples: iMac, iPhone iPad, Yahoo (a little weak), Facebook (they own that word). It's all about branding. Google Kleenex or Xerox and you'll see that they're excellent sigils. The problem is, those terms have become generic. Their brand is a little weaker for it. Finally, on Twitter, @and # unleash powerful features. — [[User:Tbc|tbc]] ([[User talk:Tbc|talk]]) 15:01, 20 December 2013 (UTC)
:C++ uses symbols, but it doesn't use one to denote that an identifier is a variable (like PHP) or the type of an identifier (like early BASIC, Perl, and arguably Twitter). And when I search for X, it's either X11 (the protocol) or Xorg (the widely used server implementation). And [[wikipedia:Barney_Google_and_Snuffy_Smith|Barney Google]] had it first. --[[User:Tepples|Tepples]] ([[User talk:Tepples|talk]]) 15:55, 20 December 2013 (UTC)

Any way we can expand on the history of programming (if applicable)? Did these languages become popular in a certain order, or were they developed as a response to one another? Or is this comic simply Randall's journey through programming, not specifically tied to the popularity (or development) of certain coding languages? -- [[Special:Contributions/108.162.216.227|108.162.216.227]]

The google mentioning isn't explained well enough imo. Instead if just saying "they have a service called google plus", it should be told how the + sign is used throughout the service, like every other instance in the article. I may do the edit myself, but it's not likely. [[Special:Contributions/141.101.98.237|141.101.98.237]] 15:26, 20 December 2013 (UTC)

"Ironically, it is the name if the language itself that includes symbols."

It's not very ironic. Variable names don't include symbols, but commands do. This statement should be rewritten.

int c = 0;

c++;

c += 1;

c = c + 1;

:I find it ironic that "C++" in a statement would be interpretted as "C" and only ''post''-incremented (i.e. only incremented when ''next'' referenced). Meaning "C++" is effectively the same as "C", in its own context. They should have named it "++C", if they wanted to indicate that it was ''itself'' improved upon the original value of C. ;) [[Special:Contributions/141.101.99.229|141.101.99.229]] 16:37, 20 December 2013 (UTC)

::This is an incorrect interpretation of the statement c++. c++ as a standalone statement, on a line by itself, will result in c being exactly one greater than before the statement (the value stored in that memory location will indeed be one greater); using prefix or postfix ++ in this context is functionally equivalent and most people just prefer using the postfix version. Where the distinction between the prefix and postfix versions come into play is in more complex statements where the operator's return value is not ignored. For example,

::int c = 1;
::int x = c++;

::x will be initialized to 1 because the postfix ++ operator returns the value of c before it was incremented, but the value stored in c will be 2 regardless of further reference. If, instead you initialized x using the prefix version, ++c, x would be 2 because the prefix version of ++ returns the incremented result. (Side note: it's often considered bad practice to rely on the return value of the increment and decrement operators.) [[Special:Contributions/108.162.219.227|108.162.219.227]] 20:58, 20 December 2013 (UTC)
:::No, I stand by what I say. I actually agree with your code, but freely parsing "I will use C++ for this project", as a phrase (at least the first time you utter it) might so easily be a statement that gives a direct result equal to "I will use C for this project". (It helps to have just the right geeky sense of humour, of course.) [[Special:Contributions/141.101.99.229|141.101.99.229]] 21:56, 20 December 2013 (UTC)
::::Oh, I assure you, I am quite geeky. I could, for instance, argue that you're mixing the grammars of English and C++, a natural language and context sensitive language. [[Special:Contributions/108.162.219.227|108.162.219.227]] 22:21, 20 December 2013 (UTC)

Extending the first comment above: Since the strip is known for being rather technically strict, it's odd that it says "word ... will START with", yet QBASIC variables END with symbols, and Google+ ENDS with a symbol.[[Special:Contributions/108.162.216.216|108.162.216.216]] 18:11, 20 December 2013 (UTC)

Although C++ doesn't force you to use sigils, by convention programmers would still use sigils. Conventionally, variable names were named nCount, or fCost. The first character in the variable name indicated the data type. This convention was extended by Visual C++, and it started naming interfaces starting with I. Eventually, this convention fell by the wayside because IDEs started getting smarter and you would get code complete and some sort of information via a tooltip that eliminated the need for the Sigil --[[Special:Contributions/173.245.56.24|173.245.56.24]] 18:16, 20 December 2013 (UTC)

I think this explanation could do with some better explanation of the programming concepts it describes. Not every xkcd reader will be familiar with programming languages. --[[User:Mynotoar|Mynotoar]] ([[User talk:Mynotoar|talk]]) 21:20, 20 December 2013 (UTC)

Talk:1306: Sigil Cycle

2013-12-20T20:58:23Z

108.162.219.227:

Shouldn't it be QBASIC$ (or QBASIC%), since in Basic the sigil is attached to the end of variable names? --[[Special:Contributions/173.245.53.108|173.245.53.108]] 13:19, 20 December 2013 (UTC)

Could not find where categories can be added, here's a list of suitable categories: Charts, Computers, Comics presenting a compromise Internet, Programming [[Special:Contributions/173.245.53.180|173.245.53.180]] 13:32, 20 December 2013 (UTC)

This comic de-emphasizes the value of sigils. It's very ironic that Randall chose C++, a language with symbols, to exemplify plain words. And C is a reason for not naming technologies after letters. Same with X. You have to search for "C programming language" or "X window system." It's very helpful to distinguish things with unique sigils, especially in this current age where we depend on full-text search. Just look at my login ID, tbc. I have been tbc on the Internet since 1981. But I eventually had to go by tbc0 (e.g. on Twitter) because tbc isn't unique enough. Google was named after 10^100 (an incomprehensibly large number reflecting their ambition). But that number is spelled googol. They own their spelling. Brilliant. Consider examples: iMac, iPhone iPad, Yahoo (a little weak), Facebook (they own that word). It's all about branding. Google Kleenex or Xerox and you'll see that they're excellent sigils. The problem is, those terms have become generic. Their brand is a little weaker for it. Finally, on Twitter, @and # unleash powerful features. — [[User:Tbc|tbc]] ([[User talk:Tbc|talk]]) 15:01, 20 December 2013 (UTC)
:C++ uses symbols, but it doesn't use one to denote that an identifier is a variable (like PHP) or the type of an identifier (like early BASIC, Perl, and arguably Twitter). And when I search for X, it's either X11 (the protocol) or Xorg (the widely used server implementation). And [[wikipedia:Barney_Google_and_Snuffy_Smith|Barney Google]] had it first. --[[User:Tepples|Tepples]] ([[User talk:Tepples|talk]]) 15:55, 20 December 2013 (UTC)

Any way we can expand on the history of programming (if applicable)? Did these languages become popular in a certain order, or were they developed as a response to one another? Or is this comic simply Randall's journey through programming, not specifically tied to the popularity (or development) of certain coding languages? -- [[Special:Contributions/108.162.216.227|108.162.216.227]]

The google mentioning isn't explained well enough imo. Instead if just saying "they have a service called google plus", it should be told how the + sign is used throughout the service, like every other instance in the article. I may do the edit myself, but it's not likely. [[Special:Contributions/141.101.98.237|141.101.98.237]] 15:26, 20 December 2013 (UTC)

"Ironically, it is the name if the language itself that includes symbols."

It's not very ironic. Variable names don't include symbols, but commands do. This statement should be rewritten.

int c = 0;

c++;

c += 1;

c = c + 1;

:I find it ironic that "C++" in a statement would be interpretted as "C" and only ''post''-incremented (i.e. only incremented when ''next'' referenced). Meaning "C++" is effectively the same as "C", in its own context. They should have named it "++C", if they wanted to indicate that it was ''itself'' improved upon the original value of C. ;) [[Special:Contributions/141.101.99.229|141.101.99.229]] 16:37, 20 December 2013 (UTC)

::This is an incorrect interpretation of the statement c++. c++ as a standalone statement, on a line by itself, will result in c being exactly one greater than before the statement (the value stored in that memory location will indeed be one greater); using prefix or postfix ++ in this context is functionally equivalent and most people just prefer using the postfix version. Where the distinction between the prefix and postfix versions come into play is in more complex statements where the operator's return value is not ignored. For example,

::int c = 1;
::int x = c++;

::x will be initialized to 1 because the postfix ++ operator returns the value of c before it was incremented, but the value stored in c will be 2 regardless of further reference. If, instead you initialized x using the prefix version, ++c, x would be 2 because the prefix version of ++ returns the incremented result. (Side note: it's often considered bad practice to rely on the return value of the increment and decrement operators.) [[Special:Contributions/108.162.219.227|108.162.219.227]] 20:58, 20 December 2013 (UTC)

Extending the first comment above: Since the strip is known for being rather technically strict, it's odd that it says "word ... will START with", yet QBASIC variables END with symbols, and Google+ ENDS with a symbol.[[Special:Contributions/108.162.216.216|108.162.216.216]] 18:11, 20 December 2013 (UTC)

Although C++ doesn't force you to use sigils, by convention programmers would still use sigils. Conventionally, variable names were named nCount, or fCost. The first character in the variable name indicated the data type. This convention was extended by Visual C++, and it started naming interfaces starting with I. Eventually, this convention fell by the wayside because IDEs started getting smarter and you would get code complete and some sort of information via a tooltip that eliminated the need for the Sigil --[[Special:Contributions/173.245.56.24|173.245.56.24]] 18:16, 20 December 2013 (UTC)

54: Science

2013-12-18T22:12:18Z

108.162.219.227: /* Explanation */

{{comic
| number = 54
| date = January 18, 2006
| title = Science
| image = science.jpg
| titletext = Bonus point if you can identify the science in question
}}

==Explanation==
The graph shows the relationship between energy density and frequency for two sources: the solid line represents the theoretical {{w|blackbody radiation}}, and the dots represent measurements of the {{w|cosmic microwave background radiation}}, or in short CMB. The equation is the {{w|Planck's Law}}, derived in 1900 by {{w|Max Planck}} for the energy density of blackbody radiation.

This comic shows the very close match between theory and prediction, showing that the Cosmic Background Radiation looks exactly like a blackbody at 2.73 K, which is what we would expect if the CMB is the result of the light of the {{w|Big Bang}} cooled by the expansion of the universe.

All of this comes from science, and therefore [[Randall]] is boasting that science works, since it can explain the small amount of heat in the background of the cosmos.
In using the phrase "It works, bitches", Randall quotes evolutionary biologist Richard Dawkins. Dawkins was asked in a debate about religion how he knew that science was any more real than God.

The title text praises viewers who can identify where this equation and corresponding graph come from.

==Transcript==
:[Graph of cosmic microwave background radiation: Y axis is energy density, X axis is frequency in GHz. Energy density peaks at 160.4 GHz.]
:I(f) = ((2hf^3)/(c^2))*(1/(e^(hf/(kT))-1))
:'''Science.'''
:It works, bitches.

==Trivia==
*This is the 48th comic originally posted to livejournal. The previous comic was [[50: Penny Arcade]], the next is [[51: Malaria]].
*This comic is available on a t-shirt at [http://store.xkcd.com/products/science-works the xkcd store].

{{comic discussion}}
[[Category:Comics posted on livejournal]]
[[Category:Charts]]
[[Category:Math]]
[[Category:Physics]]

749: Study

2013-12-16T18:52:34Z

108.162.219.227: /* Explanation */ grammar

{{comic
| number = 749
| date = June 4, 2010
| title = Study
| image = study.png
| titletext = Volunteers needed for a study on transmission of urushiol from digital contact with thin strips of fibrous cellulose pulp.
}}

==Explanation==
This comic is about the ubiquitous study fliers that are placed around cities and especially college campuses.

This one obviously takes it to the absurd because it is a thinly-veiled attempt to get volunteers so that their kidneys can be “harvested” or stolen. Type O is a {{w|ABO_blood_group_system|blood type}} that omits both A and B antigens so it won’t cause reaction in blood types having anti-A or anti-B antibodies and thus people having this blood type are the most valuable for transplants (there are still other antigens that can cause reactions but these two are the most important).

{{w|Urushiol}} is an oily toxic irritant present in poison ivy and some related plants, digital contact means touching something with fingers and fibrous cellulose pulp is a scientific description of paper. This together suggests that the person who put up the flier soaked the strips with urushiol and is trying to see if it will cause irritation in anyone who will touch the strips with their fingers (and it will within ten minutes).

==Transcript==
:[A posted flier with nine tear-off strips at the bottom reads: "Volunteers Needed for a scientific study investigating whether people can distinguish between scientific studies and kidney-harvesting scams. (Healthy Type-O Adults Only) TAKE ONE" Five of the nine strips are torn off.]

{{comic discussion}}