Imagine its made of putty instead of fiber. See if you can squish and stretch its surface in your mind into a sphere or flat shape without tearing it. You'll se

Imagine its made of putty instead of fiber. See if you can squish and stretch its surface in your mind into a sphere or flat shape without tearing it. You'll see the sock is homeomorphic with those shapes and there are 0 holes. Likewise see if you can imagine squishing and stretching a putty coffee mug or a straw into a torus. They both have 1 hole. Like this: https://i.ytimg.com/vi/9NlqYr6-TpA/maxresdefault.jpg https://i.ytimg.com/vi/9NlqYr6-TpA/maxresdefault.jpg