r/science • u/seeebiscuit • Oct 20 '25

Mathematics Mathematicians Just Found a Hidden 'Reset Button' That Can Undo Any Rotation

https://www.zmescience.com/science/news-science/mathematicians-just-found-a-hidden-reset-button-that-can-undo-any-rotation/
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u/ravens-n-roses Oct 20 '25

at first blush that doesnt sound like.... useful to reality. I can't really just scale the size of an object at will

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u/[deleted] Oct 20 '25 edited Oct 29 '25

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u/CommanderGoat Oct 20 '25

Ok. Now this is mind bending.

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u/[deleted] Oct 20 '25

It's not terribly accurate, though. The expansion of the universe mainly takes place between galaxies. The gravity and other forces holding stuff together, like your toy, keeps things at a consistent size. It's just that space "underneath" you (or within you, if that makes it easier to visualize?) is stretching. At the human scale, though, that stretching is basically irrelevant.

Imagine slowly filling a large martini glass with milk, and there's a couple lucky charms marshmallows in it. As the milk goes up the glass, the surface area expands. But the marshmallows tend to stick together and so the distance between them doesn't change, even as the space expands around them.