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/sci/ - Science & Math

File: 13 KB, 342x359, 41m5louvf4L._SX342_.jpg [View same] [iqdb] [saucenao] [google]

Anonymous Mon Dec 4 11:24:12 2017 No.9342244 [Reply] [Original]

How many holes are there in this shape?

>>	Anonymous Mon Dec 4 11:26:10 2017 No.9342252 >>9342244 0 holes, 4 handles.

>>	Anonymous Mon Dec 4 11:27:31 2017 No.9342256 >>9342244 There are actually infinitely many holes.

>>	Anonymous Mon Dec 4 11:29:04 2017 No.9342259 2 what do i win?

>>	Anonymous Mon Dec 4 11:29:23 2017 No.9342261 6 holes

>>	Anonymous Mon Dec 4 11:30:34 2017 No.9342265 >>9342244 Isn't it topologically equivalent to a spherical "hull" with 4 holes drilled into it?

>>	Anonymous Mon Dec 4 11:33:56 2017 No.9342274 >>9342265 Nah.

>>	Anonymous Mon Dec 4 11:36:53 2017 No.9342280 >>9342274 Yeah. There are 4 holes, the pipe/cross shape is a red herring. Put it this way: if I blew smoke into one end, out of how many places would smoke emanate? Three plus one (the hole I'm blowing the smoke into) equals four.

Anonymous Mon Dec 4 11:44:39 2017 No.9342298

>>9342265
actually, the metal in the shape has a thickness, so it is merely homotopic to a spherical hull with 4 holes

if you treat it as a 3-manifold then its boundary is a 3-handled sphere (homeomorph the four "holes" together in a row on top of the sphere to see the handles)

>>	Anonymous Mon Dec 4 11:48:34 2017 No.9342308 >>9342280 Nah-ah. (Re-read your topology textbook.)

Anonymous Mon Dec 4 11:52:04 2017 No.9342322

>>9342298
>actually, the metal in the shape has a thickness, so it is merely homotopic to a spherical hull with 4 holes

Okay, I'm with you there.

>if you treat it as a 3-manifold then its boundary is a 3-handled sphere (homeomorph the four "holes" together in a row on top of the sphere to see the handles)

But have no idea what this means.

>>9342308
>Nah-ah. (Re-read your topology textbook.)

If only I'd ever read one...

>>	Anonymous Mon Dec 4 11:59:47 2017 No.9342336 >>9342244 4 2D holes 2 3D holes PROVE ME WRONG BRAINLETS

>>	Anonymous Mon Dec 4 13:18:16 2017 No.9342468 >>9342244 one hole if a hole is defined as an opening through an object with no restrictions on how many other sides to the hole there are, then this is one hole with four exits, including the entrance as an exit

>>	Anonymous Mon Dec 4 13:20:40 2017 No.9342473 >>9342336 >2d hole >implying there is such a thing

>>	Anonymous Mon Dec 4 13:24:15 2017 No.9342481 >>9342473 Black holes?

>>	Anonymous Mon Dec 4 13:25:38 2017 No.9342485 >>9342481 blackholes in 3d are 3d themselves

>>	Anonymous Mon Dec 4 13:38:27 2017 No.9342515 3 holes one opens so much that it becomes a sheet with 3 holes

>>	Anonymous Mon Dec 4 14:31:14 2017 No.9342654 >>9342244 3 holes These guys understand >>9342298 >>9342515

>>	Anonymous Mon Dec 4 14:37:15 2017 No.9342672 >>9342322 imagine putting your hands in the bottom hole and gaping it infinitely wide in every direction until the pipe is a flat sheet then you'll see the edges of that hole are the edges of a flat sheet which has 3 holes in the middle of it

>>	Anonymous Mon Dec 4 14:43:46 2017 No.9342687 >>9342672 Ah I see what you mean.

>>	Anonymous Mon Dec 4 15:55:01 2017 No.9342822 >>9342244 3, topologically it's a shirt. Just impose it onto a 2d plane and you see that there is 3 holes pretty easily.

Anonymous Mon Dec 4 16:10:36 2017 No.9342849

>>9342822
Makes no sense the boundary could still be classified as a hole.

And what about the laws of objectivity? Which hole do you select to be the boundary? Select a different hole and you wind up with a set of holes different from the last, or is there some kind of formal logic in topology that excludes counting in this manner?

>>9342244
1, 2 and 6 are all acceptable answers.

>>	Anonymous Mon Dec 4 16:16:08 2017 No.9342875 File: 68 KB, 1195x399, holes.jpg [View same] [iqdb] [saucenao] [google] 2

>>	Anonymous Mon Dec 4 16:18:02 2017 No.9342881 File: 18 KB, 175x135, 1289790689514.jpg [View same] [iqdb] [saucenao] [google] >>9342672 >infinitely wide >edges

>>	Anonymous Mon Dec 4 18:38:28 2017 No.9343180 1 hole, radial patterned 4 times. t. ME

>>	Anonymous Mon Dec 4 18:47:36 2017 No.9343200 >>9342849 >is there some kind of formal logic in topology that excludes counting in this manner I'd have thought that, topologically speaking, all holes are equal. >inb4 some sex pun

>>	Anonymous Mon Dec 4 19:08:35 2017 No.9343239 >>9342515 >>9342654 >>9342822 you're forgetting the hole at infinity

>>	Anonymous Mon Dec 4 19:13:24 2017 No.9343252 Pre-calc student here. I say 4: The one on the top, bottom, left and right.

>>	Anonymous Mon Dec 4 19:14:23 2017 No.9343256 >>9342244 2 holes. Unless the edges are sharp, in which case it will disintegrate in a moment.

>>	Anonymous Mon Dec 4 19:27:42 2017 No.9343289 File: 47 KB, 370x385, 1345329792160.jpg [View same] [iqdb] [saucenao] [google] >>9342672 >imagine putting your hands in the bottom hole and gaping it infinitely wide in every direction Now you're talking my language.

>>	Anonymous Mon Dec 4 19:34:27 2017 No.9343305 >>9343289 What are your thoughts on (John) matrices?

>>	Anonymous Mon Dec 4 19:43:32 2017 No.9343331 >>9342244 Define 'hole'

>>	Anonymous Mon Dec 4 19:54:24 2017 No.9343350 >>9342244 Assuming all holes are linked on the inside, and we propose the "surface" has thickness, it's a genus 3. Think of what happens when you bend up the two arms and smash it. You get three donuts merging together.

>>	Anonymous Mon Dec 4 19:54:42 2017 No.9343352 0 Holes must either be drilled, dug or otherwise carved. This was extruded, cut, and welded. When you look at an exhaust pipe, do you think "wow, look at that long hole"?

>>	Anonymous Mon Dec 4 19:55:37 2017 No.9343356 >>9343352 Engineer detected.

>>	Anonymous Mon Dec 4 19:58:09 2017 No.9343362 >>9343356 Just means my answer is more applicable.

>>	Anonymous Mon Dec 4 20:01:00 2017 No.9343365 >>9343350 two donuts. its a genus 2 surface.

>>	Anonymous Mon Dec 4 20:02:08 2017 No.9343370 File: 325 KB, 300x225, 1198336464888.gif [View same] [iqdb] [saucenao] [google] >>9342244 4 holes I can stick my dick in it 4 different ways

>>	Anonymous Mon Dec 4 20:07:50 2017 No.9343383 >>9343365 oh god im stupid. it is genus 3.

>>	Anonymous Mon Dec 4 20:23:09 2017 No.9343415 >>9342244 is that a threat?

>>	Anonymous Mon Dec 4 20:35:08 2017 No.9343443 3 holes cover 3 of the holes and it turns into a sock which is equivalent to a sheet

>>	Anonymous Mon Dec 4 20:50:24 2017 No.9343481 What's the point of topology?

>>	Anonymous Mon Dec 4 20:55:23 2017 No.9343494 >>9343481 What's the point of anything?

>>	Anonymous Mon Dec 4 22:44:04 2017 No.9343738 >>9342244 2 holes t. brainlet cnc operator

>>	Anonymous Mon Dec 4 22:56:49 2017 No.9343765 >>9342244 Imagine building it as the composition of a bunch of tori. You can only construct that shape from three tori, so it has three holes.

>>	Anonymous Mon Dec 4 23:02:52 2017 No.9343779 http://home.sandiego.edu/~baber/metaphysics/readings/Lewis&Lewis.Holes.pdf

>>	Anonymous Mon Dec 4 23:29:18 2017 No.9343825 File: 34 KB, 347x428, 4cc9fd9ce9cfae337d35f28704010513.jpg [View same] [iqdb] [saucenao] [google] >>9342244 Oh look, another discussion about DEFINITIONS to keep the retards busy

>>	Anonymous Mon Dec 4 23:46:09 2017 No.9343853 >>9342244 4, everyone else can fuck off.

>>	Anonymous Tue Dec 5 00:02:13 2017 No.9343876 >a : an opening through something : perforation The coat has a hole in it. a bullet hole 4

>>	Anonymous Tue Dec 5 00:08:55 2017 No.9343888 4 Everything else is just retarded mental gymnastics.

>>	Anonymous Tue Dec 5 00:14:04 2017 No.9343898 >>9343370 /thread

Anonymous Tue Dec 5 00:24:45 2017 No.9343917
File: 131 KB, 1207x595, symmetry.png [View same] [iqdb] [saucenao] [google]

>>9343370
But can you really?
Suppose you are actually holding the object to insert your penis. You first insert it through hole A (see figure). Then you want to insert it through hole B, but you can't just teleport on top of the pipe, you would have to rotate the object so that hole B would be in position to hole A and after you do that, because of the symmetry of the system the new configuration is actually completely indistinguishable from when you fucked it from A.

Therefore by your logic, there is only one hole, as you can only fuck it in one way.

>>	Anonymous Tue Dec 5 00:25:09 2017 No.9343918 >>9342244 Zero.

>>	Anonymous Tue Dec 5 00:29:50 2017 No.9343925 >>9343917 write 1, 2, 3, and 4 on each extension from the middle to differentiate them

>>	Anonymous Tue Dec 5 00:31:00 2017 No.9343930 >>9343925 But that is not given in the OP. The object is perfectly symmetrical. All fuck-orientations are equivalent.

>>	Anonymous Tue Dec 5 00:45:43 2017 No.9343956 >>9343370 so you have a hole in your hand? are you christ? is this the miracle of christmas?

>>	Anonymous Tue Dec 5 02:09:50 2017 No.9344048 3 obviously

>>	Anonymous Tue Dec 5 02:11:44 2017 No.9344053 File: 258 KB, 1484x1352, 1494478335153.jpg [View same] [iqdb] [saucenao] [google] >pic related has two holes >this is what 4-brainlets actually believe

>>	Anonymous Tue Dec 5 02:26:34 2017 No.9344065 >>9343352 >>9343356 >>9343362 Underrated conversation.

>>	Anonymous Tue Dec 5 12:29:13 2017 No.9344833 >>9342875 That is six holes.

>>	Anonymous Tue Dec 5 12:35:12 2017 No.9344846 >>9343917 Someone call Gene Ray. We timecube now.

>>	Anonymous Wed Dec 6 04:17:36 2017 No.9346527 File: 22 KB, 990x545, triple-torus.png [View same] [iqdb] [saucenao] [google] >>9342322 here's how i visualized it

>>	Anonymous Wed Dec 6 04:42:56 2017 No.9346561 >>9346527 How do you go from 3 to 4?

>>	Anonymous Wed Dec 6 08:48:26 2017 No.9346806 >>9346527 Fuck, that's far more clever than my approach.

Anonymous Wed Dec 6 08:51:05 2017 No.9346812
File: 332 KB, 988x710, Untitled.png [View same] [iqdb] [saucenao] [google]

>>9342244
If we assume a 50% probability of flow in each direction and the instantaneous flow in one direction blocks the instantaneous flow in the other direction:
a) there is a 50% probability of there being one hole.
b) there is a 50% probability of there being no holes.

>>	Anonymous Wed Dec 6 09:53:59 2017 No.9346885 >>9343443 /thread

>>	Anonymous Wed Dec 6 10:04:02 2017 No.9346895 >>9342244 8

>>	Anonymous Wed Dec 6 10:14:03 2017 No.9346907 File: 23 KB, 1563x363, Untitled.png [View same] [iqdb] [saucenao] [google] >>9346527 Got no idea how that's supposed to work, but here's how I did it.

>>	Anonymous Wed Dec 6 10:21:35 2017 No.9346925 2; the left and bottom ones could be filled

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