Comments on: Rational Irrationality

By: A brain teaser: Jack is looking at Anne… « Mass Validation*

A brain teaser: Jack is looking at Anne… « Mass Validation* — Sun, 29 Nov 2009 12:14:31 +0000

[...] http://www.thebigquestions.com/2009/11/24/rational-irrationality/ Share and [...]

By: Weekend Roundup at Steven Landsburg | The Big Questions: Tackling the Problems of Philosophy with Ideas from Mathematics, Economics, and Physics

Sat, 28 Nov 2009 07:04:22 +0000

[...] had a little math this week, and then some more serious math, including my attempt to squeeze the entire gist of [...]

By: acucucuuc

acucucuuc — Tue, 24 Nov 2009 19:50:48 +0000

Actually, the correct answer is (c), since the problem does not require that Anne be a person. She could be a cocker spaniel, parakeet, etc. When she is one of those, a married person is not looking at an unmarried person.

By: SteveJ

SteveJ — Tue, 24 Nov 2009 19:13:33 +0000

Chris: you don’t need to know whether Anne is married, and George may as well have her eyes closed, it doesn’t affect the answer. Either Anne is married or she isn’t – in each case consider whether or not a married person is looking at an unmarried person.

Steven: If Anne is British, and in a civil partnership, is she (a) married; (b) unmarried; (c) either a or b, but the proof still works; or (d) cannot advise since there is no suitable precedent in law? ;-)

By: toss255

toss255 — Tue, 24 Nov 2009 19:00:14 +0000

and (sqrt(2n))^sqrt(2a)^sqrt(2b) is rational when ab is a perfect square?

By: Chris

Chris — Tue, 24 Nov 2009 18:08:30 +0000

As a complete moron when it comes to math, what on God’s (the spaghetti monster of course) green earth does all this mean?

What is the answer? Is a married person looking at another married person OR NOT? My initial answer was “Oh well it’s a trick because they don’t tell you if Anne is married OR if George is looking at Jack.” Expecting to see something like that, there is this mind boggling (to me) math proof. What the heck does it mean in “common sense” terms?

By: Dave

Dave — Tue, 24 Nov 2009 14:22:41 +0000

Gotcha – looks weird on my browser. All makes sense.

Thanks Steve

PS will you be doing a book tour at all?

By: Steve Landsburg

Steve Landsburg — Tue, 24 Nov 2009 14:10:00 +0000

Dave: The line above the 2 is part of a square root sign. I hope it shows correctly in all browsers.

By: Dave

Dave — Tue, 24 Nov 2009 13:47:27 +0000

It’s been way too long – what does the line above the 2 mean? doesn’t it mean it repeats indefinately?

Sorry – been alot of drinks since high school Maths

By: Steve Landsburg

Steve Landsburg — Tue, 24 Nov 2009 13:35:18 +0000

toss255: Yes, the result is transcendental (so it’s irrational). But that’s hard to prove. The point is that we don’t need to know this in order to get the result we want.