Day 9 | LThMath Advent Calendar
Yesterday, I spoke about topology in general. There is still one piece of information that I would like to share. It is funny, interesting and a bit of a surprise at first glance. I remember how amused I was first time I learnt about this. A doughnut and a coffee cup I never imagined that a doughnut and a coffee cup have anything in common. It never occured to me to look at the number of holes in a surface. Genus In mathematics, genus (plural genera) has a few different, but