10-327/Classnotes for Thursday October 21 - Revision history

Drorbn at 22:32, 6 November 2010

2010-11-06T22:32:34Z

← Older revision		Revision as of 18:32, 6 November 2010
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	==Riddle Along==		==Riddle Along==
	Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?		Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color? Sorry, I meant 3, not 4!

	[[10-327/Solution to coloring R2]]		[[10-327/Solution to coloring R2]]
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	** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)		** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)
	***Perhaps I am misreading the question, but according to the Wikipedia article and some quick conformational googling, it seems to be an open question as to whether or not it is possible with four colours. Three and Seven seem to be the easy bounds. Though, I suppose it is possible that four has recently been ruled out and the results require a bit more searching to find. Indecently, this was the Wikipedia's Mathmatics portal picture of the month which is how I stumbled across it. - [[User:Johnfleming\|Johnfleming]]		***Perhaps I am misreading the question, but according to the Wikipedia article and some quick conformational googling, it seems to be an open question as to whether or not it is possible with four colours. Three and Seven seem to be the easy bounds. Though, I suppose it is possible that four has recently been ruled out and the results require a bit more searching to find. Indecently, this was the Wikipedia's Mathmatics portal picture of the month which is how I stumbled across it. - [[User:Johnfleming\|Johnfleming]]
			**** Ooops, I had a typo! Sorry. Anyway, now the problem becomes a bit pointless, as right above there's a link to its solution... [[User:Drorbn\|Drorbn]] 18:32, 6 November 2010 (EDT)

Johnfleming: /* Riddle Along */

2010-11-06T17:32:38Z

Riddle Along

← Older revision		Revision as of 13:32, 6 November 2010
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	*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?		*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?
	** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)		** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)
	***Perhaps I am misreading the question, but according to the Wikipedia article and some quick conformational googling, it seems to be an open question as to whether or not it is possible with four colours. Three and Seven seem to be the easy ~~bound~~. Though, I suppose it is possible that four has recently been ruled out and the results require a bit more searching to find. Indecently, this was the Wikipedia's Mathmatics portal picture of the month which is how I stumbled across it. - [[User:Johnfleming\|Johnfleming]]		***Perhaps I am misreading the question, but according to the Wikipedia article and some quick conformational googling, it seems to be an open question as to whether or not it is possible with four colours. Three and Seven seem to be the easy bounds. Though, I suppose it is possible that four has recently been ruled out and the results require a bit more searching to find. Indecently, this was the Wikipedia's Mathmatics portal picture of the month which is how I stumbled across it. - [[User:Johnfleming\|Johnfleming]]

Johnfleming: /* Riddle Along */

2010-11-06T17:23:27Z

Riddle Along

← Older revision		Revision as of 13:23, 6 November 2010
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	*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?		*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?
	** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)		** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)
			***Perhaps I am misreading the question, but according to the Wikipedia article and some quick conformational googling, it seems to be an open question as to whether or not it is possible with four colours. Three and Seven seem to be the easy bound. Though, I suppose it is possible that four has recently been ruled out and the results require a bit more searching to find. Indecently, this was the Wikipedia's Mathmatics portal picture of the month which is how I stumbled across it. - [[User:Johnfleming\|Johnfleming]]

Drorbn at 12:58, 6 November 2010

2010-11-06T12:58:10Z

← Older revision		Revision as of 08:58, 6 November 2010
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	[[10-327/Solution to coloring R2]]		[[10-327/Solution to coloring R2]]
	*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?		*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?
			** Only to give the relatively easy bound... [[User:Drorbn\|Drorbn]] 08:58, 6 November 2010 (EDT)

Johnfleming: /* Riddle Along */

2010-11-06T00:36:08Z

Riddle Along

← Older revision		Revision as of 20:36, 5 November 2010
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	[[10-327/Solution to coloring R2]]		[[10-327/Solution to coloring R2]]
			*Are you asking us to solve the [http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem Hadwiger-Nelson problem]?

Johnfleming: /* Riddle Along */

2010-10-22T01:25:37Z

Riddle Along

← Older revision		Revision as of 21:25, 21 October 2010
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	==Riddle Along==		==Riddle Along==
	Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?~~<br>~~		Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?

	[[10-327/Solution to coloring R2]]		[[10-327/Solution to coloring R2]]

Johnfleming: /* Riddle Along */

2010-10-22T01:25:07Z

Riddle Along

← Older revision		Revision as of 21:25, 21 October 2010
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	==Riddle Along==		==Riddle Along==
	Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?		Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?<br>
	[[10-327/Solution to coloring R2]]		[[10-327/Solution to coloring R2]]

Johnfleming: /* Riddle Along */

2010-10-22T01:24:50Z

Riddle Along

← Older revision		Revision as of 21:24, 21 October 2010
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	==Riddle Along==		==Riddle Along==
	Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?		Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?
			[[10-327/Solution to coloring R2]]

Johnfleming at 01:23, 22 October 2010

2010-10-22T01:23:56Z

← Older revision		Revision as of 21:23, 21 October 2010
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	[http://katlas.math.toronto.edu/drorbn/images/e/e5/10-327-lec11p07.jpg Lecture 11 page 7]		[http://katlas.math.toronto.edu/drorbn/images/e/e5/10-327-lec11p07.jpg Lecture 11 page 7]

			==Riddle Along==
			Can you color <math>\mathbb{R}^2</math> with 4 colors such that no points with distance one are the same color?

Drorbn at 01:08, 22 October 2010

2010-10-22T01:08:16Z

← Older revision		Revision as of 21:08, 21 October 2010
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	{{10-327/Navigation}}		{{10-327/Navigation}}

			See some blackboard shots at {{BBS Link\|10_327-101021-143325.jpg}}.

	{{Template:10-327:Dror/Students Divider}}		{{Template:10-327:Dror/Students Divider}}