On Saturday, May 31, 2025 at 5:52:02 AM UTC-6 John Clark wrote:
On Fri, May 30, 2025 at 5:59 PM Alan Grayson <[email protected]> wrote: *> You asked me what I really understand, and I told you. You can't claim that we understand mathematics because we invented it, because the same can be said of physics. * *We didn't invent the way Mercury orbits the sun, and as early as 1859 observations were good enough for us to know that Newton couldn't explain it, and in general Newton couldn't accurately predict how ANY planet that was close to its star would behave; but in 1915 Einstein could do both. So at the very least would you admit that Einstein understood gravity better than Newton did?* Yes, for sure. Definitely! I'm just saying that why anything moves in a gravity field seems unknown, even by Einstein. It's probably a postulate of GR, via the application of extremal principles. I'd like to go beyond this, to a deeper view of why there's motion induced or described by "gravity". AG *> What I can say is that you don't understand gravity, and that won't occur until there is a deeper theory which explains why motion in a gravity field obeys extremal principles* *And if tomorrow somebody comes out with a theory that says matter tells spacetime how to curve and spacetime tells matter how to move because of X then you would still say we don't understand gravity because this new theory doesn't explain why X exists.* There will likely always be unanswered questions, but you seem to be affirming the "shut up and calculate" attitude, and prefer to think we've gotten to the end of the road as far as knowledge is concerned. As far as that "quote" by Wheeler is concerned, it really says nothing IMO. How matter tells spacetime how to curve is unknown, although GR tells us how to calculate it. AG *If that's what it takes to "understand" something then it would be impossible even in principle to understand gravity. In fact it would be impossible to understand ANYTHING because even pure mathematics needs to start with unproven and unprovable axioms. * I am not opposed to postulates. I just want to know more. AG *If nothing is understandable, absolutely positively nothing, then the very word "understandable" loses its meaning because meaning needs contrast. Saying everything has the property X is operationally equivalent to saying nothing has the property X. That's why I have no patience for philosophers who triumphantly tell us that "nothing is real", it's equivalent to saying "everything is real". * What is likely true, is that there's no underlying material substance in the universe, and it's the apparent solidity and restrictions on motion in certain locations that creates the illusion of an underlying material substance. This, of course, is NOT to claim that nothing is real. AG *> I understand some of the conservation laws, such as conservation of charge and energy.* *Then by all means tell the entire world about this marvelous new understanding you have developed.* Well, one thing is clear. Consciousness is fundamental, and some claim that the structure of the human brain is very similar to the structure of the physical universe. What's your opinion on that? But at present nothing can achieved by focusing exclusively on consciousness as Cosmin does. AG *I'd love to have a deep understanding of exactly how an electron is able to generate a negative charge. I'd love to know what an electron is made of, what makes electron stuff different from non-electron stuff. B*ut remember if you say energy and electrical charge are conserved because of X then you know what the next question I'm going to ask will be. You seem stuck in a negative mode of thought. The hierachy of "turtles" might form an infinite regression, but you seem to prefer to give up at the present level despite its obvious shortcomings. Someday we might know much more than we do today. But that will never happen if your attitude prevails. I don't claim to have "the answer". But I see that you don't have it either, and sadly resort to mockery to presumably satisfy some psychological requirements. AG * John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* 08 -- 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 view this discussion visit https://groups.google.com/d/msgid/everything-list/b53089a9-b50e-4362-8232-eaaf8cb4919fn%40googlegroups.com.
