On Sunday, June 15, 2025 at 6:40:44 PM UTC-6 Brent Meeker wrote:
On 6/15/2025 4:48 AM, John Clark wrote: On Sat, Jun 14, 2025 at 11:42 PM Alan Grayson <[email protected]> wrote: *...* *>> do you have a better definition of time than "what a clock measures"? I don't. * *> Sure; time is caused by the existence of observed events. No events. No time. Nothing to do with clocks, AG * The events have to be time-like separated, i.e. "at the same place" in some reference frame. *An event is defined as a specific space in 4D spacetime and a specific TIME. So if you use time in a definition of time you get into an infinite regress. * *>> If it was impossible to make a clock, if nothing occurred in a periodic manner, then the concept of time would be meaningless.* *> A clock doesn't have to be periodic. It can be linear. It just needs to assign a unique real number to each event being observed. AG* *So you think a clock could be made by making a list of the position of every particle in the universe with respect to time, * I doubt AG thinks that. But linear clocks are not unusual in thought experiments. Gallileo showed that balls rolling down an inclined plane could be used as a clock. *but without a clock how do you know what time it is? And even if you could somehow manage to make such a list, how could you know which way to read it? We can tell which way the arrow time is pointing because tomorrow will have more entropy than today, but that would no longer be true when the universe has reached heat death and entropy has risen to a maximum. * *>> The 4D shape of the resulting spacetime is determined by how the matter/energy is distributed, and its precise shape can be calculated with Einstein Field Equations, which uses 4D non-Euclidean tensor calculus. * *> What's obviously lacking is a physical mechanism to get to your conclusion. AG* *My problem is I don't know what sort of explanation would satisfy you. Give me an example of a phenomenon, ANY phenomenon physical or otherwise, that you feel has a satisfactory explanation and doesn't generate additional questions that are very obvious. * *> Insofar as you defend the Gospel, and vehemently I might add, although at some level you don't think GR is the end of the road, but emotionally you do. AG * You know very well since I've posted it repeatedly that GR isn't the "end of the road" because it is inconsistent with quantum mechanics and it predicts unphysical infinities in many cases. Brent That was written to Clark! You've done that before, attributing something posted to the wrong source. 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/7a528981-87e1-4371-a540-7b0ec6d06c4an%40googlegroups.com.
