Brent, Sure, I understand this and AGREE with it. It's just standard relativity theory.
But it's a description of CLOCK time simultaneity, It does NOT say anything about being in a present moment of p-time. Edgar On Friday, February 7, 2014 7:11:42 PM UTC-5, Brent wrote: > > On 2/7/2014 10:01 AM, Jesse Mazer wrote: > > > On Fri, Feb 7, 2014 at 12:40 PM, Edgar L. Owen <[email protected]<javascript:> > > wrote: > >> Jesse, >> >> BTW, your own operational definition proves that time flows. Because >> your reflected light will always arrive back to you later on your clock >> than when it was sent. >> > > > And how does that prove that time "flows" in a non-block-timey sense? > From a geometric point of view, it just means that if you have a v-shaped > path through spacetime of a light signal that intersects my worldline at > two different points, then those two events have different proper times on > my clock (because naturally, *any* two distinct points on my worldline have > distinct proper times). If you're just talking about the fact that the > event of the signal being sent always happens at an earlier proper time > than the event of it being received, that's ultimately a consequence of the > thermodynamic arrow of time and the fact that the entropy of the universe > is continually increasing from a low-entropy Big Bang--if the laws of > physics are deterministic it would in principle be possible to set up a > special set of initial conditions for an isolated system that would ensure > entropy would decrease towards a future minimum rather than increase, and > in such a system there would be time-reversed signal "reception" events > that happened before time-reversed "transmission" events. > > > I think Jesse is doing about as good of job of explaining SR as can be > done in just words, but I'm starting to feel sorry for him. So here's some > diagrams illustrating the relativity of simultaneity. Here's a stationary > observer, SO, (i.e. any observer in his own inertial frame) and he send out > two light pulses, one to the right and one to the left, at time 0. They > bounce off reflectors which happen to be at locations 5 units left and 5 > units right of his position. He sees the reflected flash from the left and > from the right at the same time t=10. Since he got both returns at the > same time he knows that the reflections happened at the same time, namely > t=5 (assuming only that the speed of light is the same in both directions - > notice this wouldn't be true for a sound reflection in the presence of > wind). So the two reflection events are simultaneous at different > locations, according the first, stationary observer. > > But now consider a rightward moving observer that happens to pass the > stationary observe just as he emits the two light pulses. The rightward > observer, RO, also sees the pulses, but he sees the red return on the right > after 7.4 ticks of his clock and so he concludes that the reflection event > happened at t'=3.7 where t' is his clock time also starting from where SO > and RO passed. And RO sees the yellow return flash at t'=13.6, so he > concludes that the left reflection event happened at t'=6.8. Not at all > simultaneous with the right event. So who's right? > > > > > > The answer is neither (or both). Since the speed of light is the same in > all frames, we can just as well plot what happened the the RO frame and it > looks like this. Notice that all the same obersvations are true. The SO > still sees both returns at the same time t=0 and still concludes they are > simulatneous and were 5 units away. The RO still sees the returns at > t'=7.4 and t'=13.6 and he concludes the events were 3.7 and 6.8 units away > respectively. So "simultaneous" at different locations is meaningless. > > > > Brent > -- 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 http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
