Singular Homology, Each Euclidean Space is Distinct

Each Euclidean Space is Distinct

Is the plane really different from 3 space? Or is there a homeomorphism that equates the two? Both sets have the same cardinality, so there is a function, a bijection, that maps R2 onto R3. Is there a bijection that preserves open sets? There is not, because the spaces are topologically distinct.

Suppose f is a homeomorphism between R2 and R3. Take the compactification of the domain and the range to get S2 and S3 respectively. Let f map ω to ω. Verify that f is still a homeomorphism. Now the two spheres are homeomorphic. This has been ruled out by the previous theorem. Therefore each euclidean space Rn is distinct.

Since Rn maps homeomorphically onto the interior of Dn, open balls of different dimensions are also topologically distinct.