Math Memes

1531 readers

1 users here now

Memes related to mathematics.

Rules:
1: Memes must be related to mathematics in some way.
2: No bigotry of any kind.

founded 1 year ago

MODERATORS

[email protected]

354

Proof by fucking obviousness (sh.itjust.works)

submitted 4 weeks ago by [email protected] to c/[email protected]

65 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 10 points 3 weeks ago (6 children)

Yeah, the four color problem becomes obvious to the brain if you try to place five territories on a plane (or a sphere) that are all adjacent to each other. (To require four colors, one of the territories has to be surrounded by the others)

But this does not make for a mathematical proof. We have quite a few instances where this is frustratingly the case.

Then again, I thought 1+1=2 is axiomatic (2 being the defined by having a count of one and then another one) So I don't understand why Bertrand Russel had to spend 86 pages proving it from baser fundamentals.

[–] [email protected] 4 points 3 weeks ago

Yeah, the four color problem becomes obvious to the brain if you try to place five territories on a plane (or a sphere) that are all adjacent to each other.

I think one of the earliest attempts at the 4 color problem proved exactly that (that C5 graph cannot be planar). Search engines are failing me in finding the source on this though.

But any way, that result is not sufficient to proof the 4-color theorem. A graph doesn’t need to have a C5 subgraph to make it impossible to 4-color. Think of two C4 graphs. Choose one vertex from each- call them A and B. Connect A and B together. Now make a new vertex called C and connect C to every vertex except A and B. The result should be a C5-free graph that cannot be 4-colored.

load more comments (5 replies)