Poincaré's Conjecture 1

"This conjecture states that the only compact three dimensional simply connected manifold is a three dimensional sphere."

Also we can say:

"that every compact and simply connected 3-manifold is a 3-sphere".

I am back. I was away from a nice place where to think and write. I found this statement in:

Christina Sormani's, piece on this intriguing piece of Mathematics.

I hope I can understand the General Relativity and Thermodynamics implications of Perelman's work.