On Sunday, October 28, 2018 at 2:55:30 PM UTC, John Clark wrote: > > On Sun, Oct 28, 2018 at 8:12 AM <[email protected] <javascript:>> wrote: > > >> > *the Eastern mystics could very well be right that the external world >> is illusory.* > > > Mystics love to say stuff like that because they think it sounds deep, but > I don't think it is because they never explain how the illusion works, they > don't even know what they mean by "illusory"; they can't say how things > would be different if the external world were NOT illusory. >
*True, they can't explain why it is so, if it is so, but they don't assert it to simply to impress the masses. AG * > > > In my view, what's primary is space which somehow produces restrictions >> on directions of motion, > > > The idea of change is meaningful only if its specified over what > dimensions the change is occuring. Motion is a change in the position in > space with respect to time, you can't have motion without both space and > time. That's why Hermann Minkowski, Einstein's mathematics teacher and the > discoverer of Spacetime, said "*space by itself, and time by itself, are > doomed to fade away into mere shadows, and only a kind of union of the two > will preserve an independent reality*". > *OK, then space and time, via geometry, create the illusion of matter and solidity. What's your view of Zeno's paradox which implies motion is impossible. Could motion be another illusion? AG* > > >* Inverse square is a good approximation for weak field gravity. Why not >> posit universes with inverse cube, and so on as possible universes?* > > > Actually string theory does posit something like that and uses it to > explain why gravity is so much weaker than electromagnetism or the nuclear > forces. It says there are 10 spatial dimensions but unlike the 3 we are > familiar with 7 are tightly curled up so if you moved along one of those > dimensions a microscopic distance you'd end up in the same place. It says > gravity radiates into those other dimensions and so weakens by a inverse > 9th power when things become close. Unfortunately string theory doesn't > specify exactly how curled up those dimensions are, it doesn't say how > close is close and there is no evidence any of this is true. We know > experimentally that the inverse square law is true for distances greater > than 1 mm but at distances less than that it's too hard to measure gravity > to know what's going on. > > However we might find evidence those other dimensions exist from particle > accelerators. If those 7 additional spatial dimensions are small by human > standards but much much larger than the Planck Length then when 2 protons > are forced to get so close that the distance approaches the size of those > small dimensions then gravity would no longer be a inverse r^2 law but a > inverse r^9 law; push the two particles just a little bit closer and the > gravitational force between them becomes enormously stronger. And then you > have a shot at making a Black Hole. > > The idea is that at these very small sizes gravity would be just as strong > as the other forces of nature, only at larger sizes is gravity so much > weaker than the other forces because it leaks out into the other 7 > dimensions and gets diluted. The other forces don't go into these other > dimensions and so don't get diluted. But as I said nobody knows if any of > this is true. > > Such a sub microscopic Black Hole would not be dangerous because the > smaller the Black Hole the hotter it is and so it would evaporate away by > Hawking radiation in about a billionth of a billionth of a second. But if > we made one it would be easy to detect by its decay products, and if our > accelerator was smaller than the galaxy we'd know there must be extra > dimensions and they are larger than the Planck Length or we wouldn't have > been able to make a Black Hole. > > John K Clark > > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
