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Re:Decades-Old Graph Problem Yields to Amateur Mathematician by lisper on Tuesday April 17, 2018 @05:49PM (#16862616)
Here's a chance for you to make some easy money: I'l bet you any amount you care to wager that I can color any planar map you can produce an actual drawing of with four colors.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by Someone on Wednesday April 18, 2018 @02:28AM (#16865136)
Be careful in how you phrase that. I would say graph where you say map.

Using map opens you to claims such as that a map containing the North Sea, the kingdom of the Netherlands, the kingdom of Belgium, the French Republic and the Federal Republic of Germany can’t be four-colored because they all border each other (the kingdom of the Netherlands and the French Republic on Saint Martin in the Caribbean)

Historically, other examples likely existed, as land ownership tended to be patchy in feudal Europe, and, later, colonies added borders between various European countries.

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by hinkley on Tuesday April 17, 2018 @08:46PM (#16863717)
For convex shapes, isn’t it?
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by lisper on Tuesday April 17, 2018 @09:27PM (#16863914)
Huh??? Are you asking whether the 4-color theorem only applies to maps with only convex shapes? If so, the answer is no, the theorem applies to any planar map.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by fulmicoton on Wednesday April 18, 2018 @07:45PM (#16872253)
I think he meant connex.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by pc86 on Friday April 20, 2018 @09:44AM (#16884680)
Connex isn't a word, so that's unlikely. Convex is, but that's also not what he meant.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by hermitdev on Tuesday April 17, 2018 @06:08PM (#16862739)
https://imgur.com/iU7oc8d

Theories are not laws; only takes one counter-example to disprove them.

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by jnky on Tuesday April 17, 2018 @06:11PM (#16862763)
Is this a joke? The four color theorem is a proven theorem and not some crackpot theory.

https://i.imgur.com/m3Ruasq.png

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by bronson on Tuesday April 17, 2018 @06:15PM (#16862779)
You didn't even try it, did you? Took 10 seconds.

https://imgur.com/a/1sdJ6

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by profosaur on Wednesday April 18, 2018 @06:13AM (#16866098)
I love that OP was at least willing to provide an example of a planar map that he believed could not be 4-colored. Credit for sticking his neck out.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by yoda222 on Friday April 20, 2018 @04:49AM (#16883209)
Red, blue, yellow, green. And white. That's five colors! ;-)
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by qntty on Tuesday April 17, 2018 @06:47PM (#16862967)
This is like a textbook case of the Dunning-Kruger effect
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by selestify on Wednesday April 18, 2018 @03:30AM (#16865429)
I'm really glad I'm almost never this cocksure of myself. I can't imagine the embarrassment.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by taneq on Tuesday April 17, 2018 @10:27PM (#16864143)
There's a difference between a "theory" (in popular usage) and a "theorem" (in a field like mathematics).

A theory is a hypothesis. It's a plausible-but-unproven guess.

A theorem is a fact which is known because it has been proven.

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by umanwizard on Wednesday April 18, 2018 @10:33AM (#16867683)
Just to be clear: "theory" has a lot of different meanings, depending on the context. It can mean "hypothesis", but I can think of at least three other meanings, with example phrases: "Marxist theory"[1], "the theory of evolution"[2], "group theory"[3]...

As you're probably aware, this confusing patchwork of similar and overlapping yet distinct meanings is ripe for abuse: it's what allows people to get away with saying things like "evolution is just a theory".

[1] Here it means "the collective body of work of some school of thought".

[2] "A widely-accepted, well-tested scientific explanation for a phenomenon".

[3] "A subfield of mathematics; the set of definitions, theorems, and techniques related to a particular type of abstract object" (in this case, groups).

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by taneq on Wednesday April 18, 2018 @09:20PM (#16872645)
Yeah, the word "theory" is heavily overloaded and I wanted to keep it snappy so I just specified "general usage" and "in mathematics" to try and keep it on track. :)
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by selestify on Wednesday April 18, 2018 @03:29AM (#16865416)
I would correct that, for physics at least -- "theory" is just an explanation for something. "Law" is an experimental observation that holds true, but doesn't provide an explanation. E.g. Newton's laws describe macroscopic non-relativistic motion pretty well, but do not explain motion. The theory of relativity, on the other hand, explains the description of a bunch of physical phenomena, and also has lots of evidence behind it.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by lvoudour on Wednesday April 18, 2018 @05:46PM (#16871507)
Theories are not laws; only takes one counter-example to disprove them

I agree, apparently it only took a couple of minutes in mspaint to disprove yours :)

On a serious note, what hermitdev did we've probably all done at some point in our past, especially in our youth (disparaging long-standing theories about life, science, philosophy, etc.), no need to be mean.

Few times this leads to groundbreaking revelations that help humanity progress, but most times it leads to the embarrassing conclusion that past generations were not idiots.

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by dreamcompiler on Thursday April 19, 2018 @02:32AM (#16873780)
When I was in high school I was convinced I could trisect an angle using compass and straightedge, and I told my math teacher so. He just smiled and said "Prove it."

He was a good guy. Took me several days to finally understand my mistake, but afterward I had a much better understanding of the problem

Re:Decades-Old Graph Problem Yields to Amateur Mathematician by lisper on Tuesday April 17, 2018 @06:11PM (#16862759)
So put your money where your mouth is. How much are you willing to wager?
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by slx26 on Wednesday April 18, 2018 @03:58AM (#16865568)
there are more than 7 billion people in the world. every 4.2 seconds, we collectively live more than 100 years. there's a lot of clever-thinking time in a day, it's always nice to keep that in mind
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by ErikCorry on Wednesday April 18, 2018 @03:50PM (#16870505)
I guess that's technically true, since 931 years is more than 100 years.
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by slx26 on Thursday April 19, 2018 @02:18PM (#16878519)
yeah, sorry, that was a typo, it's 1000, not 100. I calculated it a while ago. now population estimations are around 7.61 billions, which is around 1014 years every 4.2 seconds. it's an impressive amount of time
Re:Decades-Old Graph Problem Yields to Amateur Mathematician by est on Wednesday April 18, 2018 @01:41AM (#16864934)
upboated for providing a pic. Thanks man but sorry man.