Skip to main content
2 of 2
added 1 characters in body
André Henriques
  • 43.2k
  • 5
  • 130
  • 264

The fiberwise one-point-compactification of the tangent bundle of the long line (pick any smooth structure) is not normal.

The two distinguished sections of this $S^1$ bundle (the zero section & the section at infinity) cannot be separated by open subsets.

André Henriques
  • 43.2k
  • 5
  • 130
  • 264