Homotopy Equivalences

  • > In fact such a 2-sphere can be wrapped around the core an arbitrary number of times.

    This is really hard for me to visualize. What does it look like for a 2-sphere to wrap around the core multiple times? Also, I would have expected it to be able to wrap around in multiple ways since there are more dimensions here, leading to pi^2(b^3 \ {0}) = Z^2. How would one even prove that this isn't the case?

  • "Grothendieck conjectured that the infinity groupoid captures all information about a topological space up to weak homotopy equivalence"

    The homotopy hypothesis has something mystical about it.

    https://math.ucr.edu/home/baez/homotopy/homotopy.pdf

  • in terry tao’s recent interview with lex fridman there’s an interesting bit on poincaré conjecture where he goes out of his way not to use these words.

  • vaguely related : synthetic homotopies visualisation tool - https://github.com/marcinjangrzybowski/cubeViz2