3 ms·

This strikes me a lot like “flatland”, ie. there’s something there but we’re not equipped to perceive it. Our experiments are mostly like extreme extensions of

This strikes me a lot like “flatland”, ie. there’s something there but we’re not equipped to perceive it. Our experiments are mostly like extreme extensions of our own senses - seeing and touching things. But could something exist entirely within a dimensional space that we can’t touch or see? And if so how would we ever figure out how to detect it ... and even more meta, what if it was impossible for us to perceive the detection? It’s all really fascinating.

dwaltrip 8y ago
Well, it has a gravitational effect, so it definitely exists inside of our normal spacetime. Scientists have explored alternative models of gravity or spacetime with additional spatial dimensions and things like that. As far as I know, none of them are very promising. There was an interesting PBS space time video about one example recently: https://youtu.be/3HYw6vPR9qU https://youtu.be/3HYw6vPR9qU Of course, it is definitely interesting to think about :)
- burlesona 8y ago
  Interesting, I didn’t know that! I guess for me the analogy is to the sphere in flatland being perceived as a circle - we can see evidence of dark matter but so far we can’t really detect or measure it directly. I wonder if the gravitational effect is the only clue that we’ll find inside “normal” spacetime. The most exciting thing about that is the idea that the hunt for dark matter might eventually lead to an understanding of the “rest of the universe” where we would otherwise never have a hint of its existence.
stephengillie 8y ago
The problem is that gravity, like EM, follows an inverse-square rule. If gravity had a 4th dimensional component, we would expect to see an inverse-cube situation. The equation is: 1/(1-dimensions) Youtube video that explains this in depth: https://www.youtube.com/watch?v=3HYw6vPR9qU&t=726s https://www.youtube.com/watch?v=3HYw6vPR9qU&t=726s
- michaelsbradley 8y ago
  Re: EM, the Biot-Savart force law can result in long-range attractive forces proportional to d^-1 instead of d^-2. So if it’s operative at galactic and intergalactic scales (between plasma filaments) and we’re not fully taking it into account, then we may be discounting the most powerful long-range force in the universe.

dwaltrip 8y ago

Well, it has a gravitational effect, so it definitely exists inside of our normal spacetime. Scientists have explored alternative models of gravity or spacetime with additional spatial dimensions and things like that. As far as I know, none of them are very promising. There was an interesting PBS space time video about one example recently: https://youtu.be/3HYw6vPR9qU https://youtu.be/3HYw6vPR9qU Of course, it is definitely interesting to think about :)

burlesona 8y ago
Interesting, I didn’t know that! I guess for me the analogy is to the sphere in flatland being perceived as a circle - we can see evidence of dark matter but so far we can’t really detect or measure it directly. I wonder if the gravitational effect is the only clue that we’ll find inside “normal” spacetime. The most exciting thing about that is the idea that the hunt for dark matter might eventually lead to an understanding of the “rest of the universe” where we would otherwise never have a hint of its existence.

stephengillie 8y ago

The problem is that gravity, like EM, follows an inverse-square rule. If gravity had a 4th dimensional component, we would expect to see an inverse-cube situation. The equation is: 1/(1-dimensions) Youtube video that explains this in depth: https://www.youtube.com/watch?v=3HYw6vPR9qU&t=726s https://www.youtube.com/watch?v=3HYw6vPR9qU&t=726s

michaelsbradley 8y ago
Re: EM, the Biot-Savart force law can result in long-range attractive forces proportional to d^-1 instead of d^-2. So if it’s operative at galactic and intergalactic scales (between plasma filaments) and we’re not fully taking it into account, then we may be discounting the most powerful long-range force in the universe.