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Topic: cotpi 69 - Black and white plane
Replies: 26   Last Post: Oct 9, 2013 10:23 AM

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 Pubkeybreaker Posts: 1,683 Registered: 2/12/07
Re: cotpi 69 - Black and white plane
Posted: Oct 2, 2013 12:31 PM

On Wednesday, October 2, 2013 12:17:25 PM UTC-4, Susam Pal wrote:
> How can you construct a plane where every point is coloured either black or white such that two points of the same colour are never a unit distance apart? -- Originally posted at: http://cotpi.com/p/69/ Puzzles IRC channel: ##puzzles on irc.freenode.net Puzzles IRC webchat: http://webchat.freenode.net/?channels=##puzzles

It does not seem possible. Take any point. Suppose it is white.
It is the center of a circle (of radius 1). All points on that circle must
then be black. But given any point on that circle there is another point
on the circle at distance 1. Both points are the same color.

Unless, of course, I am being completely stupid.

Date Subject Author
10/2/13 cotpi
10/2/13 Pubkeybreaker
10/2/13 quasi
10/2/13 Mike Terry
10/6/13 David Bernier
10/6/13 David Bernier
10/6/13 David Bernier
10/6/13 David Bernier
10/6/13 David Bernier
10/6/13 quasi
10/6/13 quasi
10/6/13 David Bernier
10/6/13 David Bernier
10/6/13 quasi
10/6/13 David Bernier
10/9/13 Phil Carmody
10/9/13 David Bernier
10/2/13 Eric Lafontaine
10/2/13 Michael F. Stemper
10/2/13 quasi
10/2/13 quasi
10/2/13 Haran Pilpel
10/2/13 quasi
10/2/13 quasi
10/2/13 Ted Schuerzinger