zipsglacier

@zipsglacier@lemmy.world

• ⁨Comment⁩ on ⁨s p h e r e⁩ ⁨⁨2⁩ ⁨weeks⁩ ago⁩:

  For each finite dimension n (1, or 2, or 3, etc…), the sphere in dimension n can’t be contracted because of that empty n-dimensional space it surrounds. But that same sphere is the “equator” of the sphere in the next higher dimension, n+1. There, the n-dimensional equator can contract along one of the hemispheres, to a pole. But then that whole (n+1)-dimensional sphere still isn’t contractible, because of the (n+1)-dimensional space it surrounds.

  BUT the (n+1)-dimensional sphere can contract along one of the hemispheres in the (n+2)-dimensional sphere. And so on.

  For any particular finite dimension n, there is an n-dimensional obstruction to contracting the sphere in that dimension. But if you go all the way to infinitely-many dimensions, there is no obstruction that ever stops contractibility of the infinite-dimensional sphere.

• ⁨Comment⁩ on ⁨I dunno⁩ ⁨⁨5⁩ ⁨months⁩ ago⁩:

  Lot of people seeming to miss that point here!

• ⁨Comment⁩ on ⁨outside inside⁩ ⁨⁨9⁩ ⁨months⁩ ago⁩:

  I don’t think that really narrows it down, but this is certainly one of the math animations of all time!

• ⁨Comment⁩ on ⁨outside inside⁩ ⁨⁨9⁩ ⁨months⁩ ago⁩:

  This animation and explanation is really good!! The studio, which is guess was new at the time, was called Pixar. According to the credits, one of the animators there shares a last name with one of the mathematicians who developed this method (Thurston).

• ⁨Comment⁩ on ⁨military industrial publishing complex⁩ ⁨⁨2⁩ ⁨years⁩ ago⁩:

  The meme leaves out the very important detail that most of the researchers working “for free” in the first panel are definitely getting paid, and usually by public funding (public universities and/or grants from taxpayer-funded institutions like NIH, NSF, etc.). That’s a big part of what makes it a scam.

• ⁨Comment⁩ on ⁨[Question] What single early moment in a movie made you realize that your low expectations for the film were going to be vastly exceeded?⁩ ⁨⁨2⁩ ⁨years⁩ ago⁩:

  Marcel, the Shell with Shoes on: the wacky shit he says in the opening interview, and the completely straight way it’s handled, made me realize this was just something completely different from the simple kids movie I was expecting.

• ⁨Comment⁩ on ⁨Stranger Than Fiction should have been Will Ferrell’s big dramatic break⁩ ⁨⁨2⁩ ⁨years⁩ ago⁩:

  “I committed them to memory… I forgot.” I think about this every time I forget something, which is a lot.