Recent content by pess5

caston, Nice idea, but actually, the computer has one of two options if one considers relative motion thru 3-space as the source for relative time ... (1) It is stationary wrt you, at which point it experiences the passage of time the same as you do, such as sitting at PC typing these...

Well joruz1, I am speculating here ... The effects of spacetime expansion I believe should be the same as the effects for acceleration. Acceleration creates time dilation and a slower tick rate for he who accelerates. In my mind, this requires that the time rate of others must speed up wrt...

Well, to ask whether we needed SR is one thing. But to ask whether we needed an invariant c is another thing altogether. Without invariant c, we are stuck with aether, absolute space, and an independent time. Basically, we would have Newton, where gravity works by magic from afar...

OK Pervect. I know Minkowski worldlines fairly well, so I'll crawl in my hole eventually here and think on it. The web links look good too. Thanx much, highly appreciated. I'll come back & bug you if I get stumped anywhere. pess

Great minds think alike, even when the one is not as quick as the other. pess

Pervect, Regarding 1 & 3, I'm good there. Regarding 2, I don't see why the train would note any accelrational differential along its length. The train doesn't appear to change at all per the passengers as it transitions frames. From the embankment, what you say would makes sense to me...

Doc Al, I studied it by Minkowski's worldlines. Indeed, the clocks remain in sync as you stated. As I originally had asked about, the clocks must slow down during acceleration identically, thus keeping the clocks in sync per the station. The clocks drop out of sync per the train...

Interesting. I do see your point. I'll think on it as to whether the clocks should appear in sync versus become desynchronized in some different fashion, and get back. pess

Doc Al, Yes, let us assume a velocity of 0.866c, so gamma=2, and an engine clock separated from the caboose clock by a proper length "x", say 5.196 lh (light hrs). In motion at 0.866c, this proper length x must be recorded as a moving 50% contracted length of x/2. scenario 1 ... train...

davidong3000, The scernario is impossible of course. I was assuming a train made of stretchable rubber, for example. Actually, I am envisioning a continuous string of clocks which would (say) be sitting in train windows facing outward so the station observer could see them ... then just...

You're right, the clocks do not change in separation per the station. A poor choice of wording on my behalf. Let me word it differently here then ... The rotation of frames is the same no matter if the train accelerates normally whereby the train contracts in length by 1/gamma, versus the...

Doc Al, Interesting, because I had never given it much thought before about a scenario such as this one. I just checked it by inspecting Minkowski worldlines wrt another scenario. The clocks must drop out of sync per the station observers even if the train stretched in such a way to...

Hi Doc Al, I agree in that the train would be ripped apart. However, it seems to me that clocks synchronized in the train frame can never remain in sync per the station observer, given they are in motion. Are you saying that the clocks remain in sync, but that they slow down identically...

3d is better than 2d, but 2d conveys the point in the simplest manner. Another way of depicting it, would be with a lot of dots showing spacetime density based on proximity to the surface of the body. Kinda like they do for electron clouds. I haven't seen a depiction like this though. pess

Good questions. Foreward clocks always lag aftward clocks, so at any instant in the stationary embankment frame, the moving engine clock will lag the moving caboose clock by gamma(-vx/c^2). This is the temporal offset portion of the time transform ... T=gamma(t-vx/c^2). The -vx/c^2 relates...