4 ms·

"Here they seem to say that on some quantum level spacetime could vary drastically." This is not a result of this theory. Our best current theories say this to

by jerf 3y ago

"Here they seem to say that on some quantum level spacetime could vary drastically." This is not a result of this theory. Our best current theories say this too: https://en.wikipedia.org/wiki/Quantum_foam https://en.wikipedia.org/wiki/Quantum_foam Spacetime getting distinctly different at very small scales is a vital part of all modern theories and I doubt it's going away. Even if spacetime is shown to be continuous itself, which I tend to personally doubt [1], getting close to the scales where the uncertainty principle becomes a major influence rather than an almost academic curiosity will inevitably have major impacts on the behavior of things. "Like giant "wrinkles" in spacetime?" Giant wrinkles in space time don't act like dark matter. They either smooth themselves out basically instantly (on cosmological scales) or form something other than a giant wrinkle, such as a cosmic string: https://en.wikipedia.org/wiki/Cosmic_string https://en.wikipedia.org/wiki/Cosmic_string In fact one of the low-key mysteries extant in the universe today is that our best theories say cosmic strings really ought to exist, but we don't see them. Though I think the confidence in our theories being pushed to that extent is low enough that this is not generally considered the biggest problem, and very unlikely to be the thing that cracks the mystery, so it isn't something that gets talked about a lot. So you could say that we actually don't "expect" space time to be homogeneous and one of the mysteries is why it observationally is! [1]: https://news.ycombinator.com/item?id=38433917 https://news.ycombinator.com/item?id=38433917

maaaaattttt 3y ago
Thank you for the link to cosmic strings! This is actually exactly what I had in mind when, as you quoted, I was mentioning wrinkles and “black trenches”. So, you don’t think structures like galaxy superclusters are a second hand visualization of the existence of cosmic strings? I know these formations could be explained by the effect of gravity of just visible matter. But maybe it’s both. Like a valley could exist because of a river and a river could exist because of a valley. Since this concept has been around for so long I have some reading to do to understand why cosmic strings are not a possible explanation for dark matter. To me high density and invisible fit the bill for dark matter quite well. Edit: never mind, continued reading the article and saw this > in the past it was thought that their gravity could have been responsible for the original clumping of matter into galactic superclusters. It is now calculated that their contribution to the structure formation in the universe is less than 10%.

by jerf 3y ago

maaaaattttt 3y ago

Thank you for the link to cosmic strings! This is actually exactly what I had in mind when, as you quoted, I was mentioning wrinkles and “black trenches”. So, you don’t think structures like galaxy superclusters are a second hand visualization of the existence of cosmic strings? I know these formations could be explained by the effect of gravity of just visible matter. But maybe it’s both. Like a valley could exist because of a river and a river could exist because of a valley. Since this concept has been around for so long I have some reading to do to understand why cosmic strings are not a possible explanation for dark matter. To me high density and invisible fit the bill for dark matter quite well. Edit: never mind, continued reading the article and saw this > in the past it was thought that their gravity could have been responsible for the original clumping of matter into galactic superclusters. It is now calculated that their contribution to the structure formation in the universe is less than 10%.