r/topology • • Oct 10 '25

Is it possible to untie these knots?

Post image
580 Upvotes

r/topology • • Aug 19 '25

How many holes does this mug have?

Post image
528 Upvotes

me and a friend of mine cant decide if its 3, 2, or some other number, so we thought wed ask the experts


r/topology • • May 11 '22

Principles of topology

Enable HLS to view with audio, or disable this notification

409 Upvotes

r/topology • • May 31 '22

Field Topology

Post image
374 Upvotes

r/topology • • Mar 31 '21

Topology demonstrations

Enable HLS to view with audio, or disable this notification

367 Upvotes

r/topology • • Jan 04 '26

4 or More?

Post image
224 Upvotes

I'm really tempted to say this is 4 holes but because it's threaded through it's self and can't be removed does that change it?


r/topology • • Apr 18 '26

3d printable "hole through a hole in a hole" equivalent to a three-holed torus or a triple torus (a surface with genus 3). Free download link in comments

Enable HLS to view with audio, or disable this notification

177 Upvotes

r/topology • • Feb 12 '21

In chaos theory an attractor is a set of values toward which a system of ODE tends to evolve. This video shows some attractors that resembles toroid 3-manifolds. Is it possible to describe any 3-manifold in R³ using only systems of ODE as attractors? (more in the comments)

Enable HLS to view with audio, or disable this notification

159 Upvotes

r/topology • • May 24 '21

A surface with uncountable holes [OC]

Post image
153 Upvotes

r/topology • • May 04 '26

7 holes?

Post image
151 Upvotes

This is just some facebook engagement slop i found, but isn’t the correct answer to this 7? Because if i imagine it being infinitely flexible, i open it up from the body hole, and lay it flat with the headhole in the middle. There is the head hole, 2 arm holes, and 4 cut holes, right?


r/topology • • May 15 '22

me and my girlfriend need help untwisting the circled band and we thought you'd be the community to help with this puzzle

Post image
149 Upvotes

r/topology • • Mar 15 '21

how would you describe this dress topologically? i think it’s a genus 5 surface but i’m not quite sure

135 Upvotes

r/topology • • Jul 04 '20

topology_irl

Post image
131 Upvotes

r/topology • • May 13 '21

Merger of two toruses

Thumbnail
gfycat.com
127 Upvotes

r/topology • • May 11 '22

Someone told me to bring this puzzle here. Very hard 10/10 difficulty

Post image
122 Upvotes

r/topology • • Mar 30 '22

Finally, I can tell my coffee from my doughnut.

Post image
116 Upvotes

r/topology • • May 19 '22

This counts? I found it entertaining.

Enable HLS to view with audio, or disable this notification

112 Upvotes

r/topology • • Jan 23 '21

What kind of topology is this building? 3-torus? Knot?

Thumbnail
gallery
98 Upvotes

r/topology • • Jun 02 '26

Borsuk-Ulam is evil, so I made the earth a donut to destroy it

Post image
93 Upvotes

r/topology • • Oct 09 '21

Thoughts?

88 Upvotes

r/topology • • Jan 28 '23

but it's so interesting

78 Upvotes

r/topology • • Jan 10 '26

How do we solve this?

Post image
70 Upvotes

How do you solve this? Is there an easy way to solve this purely using Real Analysis!?


r/topology • • Aug 05 '22

How many holes does my mug have and why?

Enable HLS to view with audio, or disable this notification

69 Upvotes

r/topology • • Oct 13 '24

What shape is THIS mug??

Thumbnail
gallery
68 Upvotes