Comments on: Dimensional Analysis http://www.explainxkcd.com/2010/01/11/dimensional-analysis/ Sun, 05 Sep 2010 05:47:38 -0400 http://wordpress.org/?v=2.8.4 hourly 1 By: laola1 http://www.explainxkcd.com/2010/01/11/dimensional-analysis/comment-page-1/#comment-1227 laola1 Fri, 15 Jan 2010 10:10:17 +0000 http://www.explainxkcd.com/?p=326#comment-1227 The comic is a response to http://scienceblogs.com/pharyngula/2009/12/the_god_equation.php?utm_source=mostactive The comic is a response to http://scienceblogs.com/pharyngula/2009/12/the_god_equation.php?utm_source=mostactive

]]> By: Michael http://www.explainxkcd.com/2010/01/11/dimensional-analysis/comment-page-1/#comment-1226 Michael Fri, 15 Jan 2010 08:23:33 +0000 http://www.explainxkcd.com/?p=326#comment-1226 And of course the comic is making fun of the way some physicists derive the general form of a formula by looking at the units of the quantities involved. Also, the teacher's first remark references the experimentalist's habit to use "to within numerical precision" (depending on the numbers you use you get something between 3 and 4, which is equal to pi "up to numerical precision") and it also makes reference to a typical crackpot argument, which tries to assign a fundamental meaning to a co-incidental combination of quantities or a co-incidental numerical result. And of course the comic is making fun of the way some physicists derive the general form of a formula by looking at the units of the quantities involved. Also, the teacher’s first remark references the experimentalist’s habit to use “to within numerical precision” (depending on the numbers you use you get something between 3 and 4, which is equal to pi “up to numerical precision”) and it also makes reference to a typical crackpot argument, which tries to assign a fundamental meaning to a co-incidental combination of quantities or a co-incidental numerical result.

]]> By: K http://www.explainxkcd.com/2010/01/11/dimensional-analysis/comment-page-1/#comment-1222 K Wed, 13 Jan 2010 20:39:32 +0000 http://www.explainxkcd.com/?p=326#comment-1222 one planck energy = 543.3 kWh (so sayeth wikipedia) ((543.3 kWh) / (3.5 million atm)) * ((48 mpg) / (21 miles)) = 3.33016968 (so sayeth google calculator) one planck energy = 543.3 kWh (so sayeth wikipedia)
((543.3 kWh) / (3.5 million atm)) * ((48 mpg) / (21 miles)) = 3.33016968
(so sayeth google calculator)

]]> By: Olie http://www.explainxkcd.com/2010/01/11/dimensional-analysis/comment-page-1/#comment-1220 Olie Wed, 13 Jan 2010 17:48:05 +0000 http://www.explainxkcd.com/?p=326#comment-1220 The units are verified and it is evaluated here: http://jaxwebster.wordpress.com/2010/01/13/xkcd-dimension-analysis/ The overview of it is that it does indeed work. The units cancel out and the values, when input, come to between 3 and 3.5 depending on the exact values you use. I wonder how long it took him to find that. The units are verified and it is evaluated here:

http://jaxwebster.wordpress.com/2010/01/13/xkcd-dimension-analysis/

The overview of it is that it does indeed work. The units cancel out and the values, when input, come to between 3 and 3.5 depending on the exact values you use. I wonder how long it took him to find that.

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