*Your response was to Brent, not me. AG* On Thursday, October 31, 2024 at 7:03:51 AM UTC-6 John Clark wrote:
On Thu, Oct 31, 2024 at 2:14 AM Alan Grayson <[email protected]> wrote: *> You didn't like my answer that it just unit matching? Imagine they had been set to 1 in the early 1800s. * *But back then they wanted to figure out if you can calculate how many miles light could travel in one second just by observing the behavior of electric and magnetic fields, so your units had better be some form of distance over time. * *And in equations, for the units to come out right the conversion factor between time t and distance d is the speed of light c, because d= ct = (miles/time)*time =d. So when you set c=1 what you're doing is saying that if, for example, the units of time that you're using are seconds and the units of distance that you're using are miles then the "natural unit" of distance is ct, the number of miles light can go in one second. * *So you can't really set the speed of light to be equal to 1 because 1 is dimensionless and the speed of light is not a dimensionless quantity; BUT you can set it to 1 NATURAL UNIT, although the words "natural units" are almost always omitted to make the equations less cluttered. And in some spacetime diagrams the axes are mislabeled as d vs t when it should be ct vs t. * > *how does mass make a gravitational field?* *The best thumbnail answer to that "how" question comes from John Wheeler "Spacetime tells mass how to move, and mass tells spacetime how to curve". As to "why" that is true nobody knows, but one thing I do know is that there are only two possibilities, either an iterated sequence of "why" questions goes on forever or the sequence terminates in a brute fact, an event without a cause. I'm 51% sure that Wheeler's statement is a brute fact. I'm 99.3% sure that consciousness is the way data feels when it is being processed intelligently.* *Wheeler's answer explains nothing, just repeating what EFE says, as if GR is the last word on gravity. There could be an unlimited sequence of "why's", or the sequence might terminate in profound knowledge, but likely * *NOT **in an event without a cause, which is unintelligible to human consciousness. AG* -- 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/2f933962-0cad-4d04-bcb1-848cc85874b1n%40googlegroups.com.
