Carleas wrote:James, I'm a little confused as to how your light-based transverse spin counter measures distance. Its spin doesn't seem to be associated with motion along the track, because 1) it is light, so its motion is not caused by contact with the track, and 2) it is transverse, so track is never a tangent to the path of the light around the circumfrence of its spin (which seems essential to a spin counter. In that case, it seems that the "spin counter" is just a light clock, as Physbang has suggested.
The issue is one of counting. The train measures the length of his journey to take only perhaps 9 seconds whereas the station measures it to be perhaps 10. There are no dilation effects for motion in the transverse directions. They both see the transverse spin counter taking the same amount of time per spin because it is spinning in a transverse direction which is the same for both observers. This results in them counting a different number of spins for the same journey.
Or do I need to prove that transverse motion to the station-train motion is not affected in either time or length? Lorentz didn't argue against that notion. I don't know anyone who does except those who don't really understand the equations. Space-time is given the coordinates of {x,y,z,t}, the changing distance between the train and the station is the x.
So you don't have to take my word for it;
Modern PhysicsModern Physics - Michael Fowler, UVa Physics. wrote:It should be mentioned that this lack of synchronization as viewed from another frame only occurs for clocks separated in the direction of relative motion. Consider two clocks some distance apart on the z′ axis of S′. If they are synchronized in S′ by both being started by a flash of light from a bulb half way between them, it is clear that as viewed from S the light has to go the same distance to each of the clocks, so they will still be synchronized (although they will start later by the time dilation factor).
Deriving the Lorentz Transformations
Let us now suppose that O′ and her crew observe a small bomb to explode in S′ at (x′, 0, 0, t′). In this section, we shall find the space coordinates and time (x, y, z, t) of this event as observed by O in the frame S. (As above, S′ moves relative to S at speed v along the x-axis). In other words, we shall derive the Lorentz transformations—which are just the equations giving the four coordinates of an event in one inertial frame in terms of the coordinates of the same event in another inertial frame. We take y′ ,z′ zero because they transform trivially—there is no Lorentz contraction perpendicular to the motion, so y = y′ and z = z′ .
Carleas wrote:(Aside: Farsight, what's the difference between a start being "really" flattened, and only being observed to be flattened? I don't mean that sarcastically or rhetorically. For all intents and purposes, the star is flattened for the observer in motion. Would it be possible to devise an experiment that would distinguish between "real" and "observed" flattening? You've mentioned an orthoganal observer, but that just seems to either put another observer in the stationary reference frame, or to introduce yet another frame of reference into the question, without truly answering the question. I tend to favor saying that it's "really" flattened, just because, for all possible applications of the idea (as far as I know), it can be treated that way.)
Btw, it doesn't really even
appear flattened. One cannot measure length in the line of motion. That is why you have 2 eyes - parallax.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony
ElseFrom THIS age of sleep, Homo-sapien shall never awake.The Wise gather together to help one another in EVERY aspect of living.You are always more insecure than you think, just not by what you think.The only absolute certainty is formed by the absolute lack of alternatives.It is not merely "
do what works", but "
to accomplish what purpose in what time frame at what cost".
As long as the authority is secretive, the population will be subjugated.
Gain is obtained by giving a lot and keeping a little.
Those who too ardently seek to be seen as correct, see only correctness in themselves.
The Social Paradox - to be well grounded and soundly harmonious, one must rise above the dirt and noise.
The One God ≡ The reason/cause for the Universe being what it is = "
The situation cannot be what it is and also remain as it is".
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