Relativity of Count – Spin Counter

Okay PhysPot, so you want to take the challenge…

You say that the Lorentz equations will show the solution to this problem. So let’s see it. Do DO know the Lorentz transformations, right? Carleas showed them to you. You should be able to find them again. So find the transformations and “plug and play”. Be sure to show your work.

But DO try to be more careful this time. The last time you tried to use equations was a bit embarrassing.

Why should I be the one doing your work for you? You are the one who is trying to actually criticize SR.

And as to my ability with the equations, anyone can see that for themselves here: viewtopic.php?f=4&t=172642&start=250#p2163463

One can also find in that thread 1) your bizarre idea that the Lorentz transformations somehow use a floating centre of frame value for “x” rather than an actual coordinate value, 2) your surrender in that thread that you were using the equations incorrectly, and 3) your claim that you would be dealing with the equations of the Lorentz transformations in this thread. That last claim of yours is an obvious lie, since you haven’t actually done anything with the equations in this thread. This is similar to your lie that you would put me on ignore. As you are incapable of actually addressing any of the questions about the science I bring up, it may be better for you to not read what I have to say. You can then blather on in ignorance and I can give warnings out to those who might be interested in the science.

I showed my logic, son. If you think you know better, show it. Now it’s your turn.

Put up or shut up.

I don’t lie, I’m not “grossly mistaken”, and this is no straw man. Take a look at our earlier discussion

You said: Do you doubt that stars are not flattened in reference frames in which these stars are in motion?
I said: A star appears to be flattened to observers in relative motion with respect to that star. But it isn’t real, as the orthogonal observers will agree.

Now please, don’t assert “according to relativity theory” to me. What you present as relativity is ersatz, and bears no resembles to Einstein’s equations of motion. Those frames of reference have no actual existence. You cannot look up to the sky and point one out. They are artefacts of measurement, and your practical choice of frame will depend upon your motion. We ignore the rotational motion of the earth in our everyday lives, and so we plot latitude and longitude. But we don’t ignore it in the Shuttle. In the Shuttle we ignore the orbital motion of the earth round the sun. But we don’t ignore it for Cassini.

It is true that all measurements are relative. This must be true simply because a measurement is a comparison, a relative measure. But if you cross-check (“transverse”) and verify your measurements then correct for consistency and cohesiveness, you discover absolute measure that is the same for all. Thus measurements are only relative when you don’t cross verify them and correct for the logical inconsistencies.

Otherwise it is like listening to only one witness or one bit of evidence at a murder trial.

Your logic is equivalent to:

  1. SR says the moon is made of made of green cheese.
  2. The moon is made of Stilton.
  3. Therefore SR is wrong.

You haven’t shown us that SR says the moon is made of green cheese and you haven’t shown us that the moon is made of Stilton. What you have been writing about SR is so off base that it is, as the physicists say, “not even wrong”. The only way that SR introduces time dilation, length contraction, and relativity of simultaneity is through the use of the Lorentz transformations (or, equivalently, through the invariant spacetime interval). If you want to make a claim about the nature of these things, you have to demonstrate them using the Lorentz transformations. Your logic is worthless without any demonstration that it applies to SR.

I have a question that I feel needs an answer concerning James S Saint and PhysBang. Do either of you feel you have sufficiently responded to each other’s assertions concerning this topic. If you believe you have responded exhaustively, then either agree or agree to disagree and leave it at that.

I’m happy to leave it at that. As long as people are able to realize that it might be the case that JSS is simply not talking about anything to do with the topic he claims to be discussing.

To my knowledge, he hasn’t actually addressed the OP. His remarks are merely concerning me, how wrong I am, how I should go read, I should show him more of how to resolve the puzzle, his opinion of me, and what others should do because of it (the very definition of “ad hominid”).

Ignoring him doesn’t shut him up nor inspire him to actually address the topic at hand rather than his opinion of me or anyone else. So yeah, I’d say that I have answered his topic relevant replies sufficiently.

Ok, then there shouldn’t be further need to address one another. If it continues, I will lock this thread and remove any remarks to each after this post.

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.

I apologize if my questions are basic, but as I said to MMP in the other thread, the best place to start is to figure out what everyone is saying, so that we can get identify and resolve the core issues.

(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.)

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 Physics

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.

But simply rotating a light clock to be orthogonal to the direction of motion couldn’t be enough to undo time dilation. Wikipedia provides this illustration of why this won’t work:
EDIT: this image didn’t work in the image tags. See it here.
This isn’t a light wheel, but the principle is the same. The distance D is greater than L when the two observers are in motion, even though the motion is orthoganl to the axis on which L sits (e.g. if motion is along the x axis, L is in the direction of y).

ASIDE_____

I’m not really talking about “appearances”, but about observed length. There are many ways to measure legth, and any could be used to meaure a distance in a moving frame (for instance, travel time of a photon)

EDIT: I added a divider to keep the aside aside.

I don’t really see the connection you are trying to make with the Wiki page.

This is what I am talking about;

Transverse Spin Non-Dilation.jpg

But it’s clear from the diagram that the distance traveled around the spiral path is greater than that traveled around the circular path, right? Similarly, in the wikipedia article, the distance traveled along D is greater than the distance traveled along L. Even though the motion of the light is orthogonal to the motion of the clock, the path is still longer for the moving observer, so the clock measures time to be passing more slowly.

How is this a spin counter? It seems to just be a light clock.

A) the train doesn’t see the spinner moving forward, so it sees only the transverse spin.
B) the component of the forward motion of the spinner is transparent and irrelevant to the station.

The spinner doesn’t change spin speed just because it was pushed along its axis.

A) Yes, and the station does see the spinner as moving. If the movement changes the calculation of the distance traveled, one will see the change and one will not.

B) What do you mean by “transparent”? Do you agree that the moving observer measures a different distance traveled by the light in the example given in the Wiki article? How does the motion of the spinner differ? Isn’t the path along a spiral of radius r greater than the path along a circle of radius r?

It doesn’t “change spin speed”, but it’s not really spinning, is it? A photon is traveling in a circle.

The station sees his own spinner and the trains spinner in the same “light”, traveling in parallel. In the simpler case of a light spinner, neither can see anything but the light traveling at the speed of light along its fixed path.

And btw, a light spinner can actually be arranged pretty easily with a standing wave laser setup. You merely measure the wave length of the standing wave to “count the spins” with the assumption that light is traveling at c. If the standing wave changes when you speed up along with the spinner by your side, you would have to conclude that light doesn’t always travel at c.

No one sees that path. We all agree that the train’s time gets dilated. That is all the Wiki article is about.

We are talking about what each observe sees. The train cannot see the spinner slow down just because the train sped up because the spinner is not spinning in the direction of the travel. This is obvious in the case of the light spinner. Also the station doesn’t see any change in his own spinner. The problem is that the train thinks it only took 9 secs to make the journey and the station thinks it took 10. So they end up counting a different number of spins.

Looking at the other guy’s spinner, they each see the same count as their own, but still different from each other’s reported count.

All that is happening is that they are measuring the train velocity as being different than what the other is measuring due to the time dilation.

Emm… is there a relevant difference?

Yes. The thought experiment began as a wheel on a track, where the circumfrence of the wheel times the number of spins of the wheel equals the length of the track. But a light “spinner” is not connected to the length of the track in the same way. In what way does this “spin counter” differ from a simple clock, about which the hands “spin” around the face? The spinning of the hands would similarly produce a different “count”, but that would similarly have nothing to do with the length of the track.

On the contrary, it is precisely because the speed of c is equal in all frames that the standing wave should be expected to change. The Wikipedia demonstrates time dilation by showing that a light being reflected between two plates moves a greater distance when the plates are in motion relative to a stationary observer. Because of this difference, the time it takes the light to complete the trip changes. In the same way, because the distance between the two plates is different in the moving and stationary frame, the standing wave would need to have two different wavelengths.

You’ve got it Carleas.

James, this is the crucial point. The electron is such a spinner, where the perimeter is moving at c. Whether it’s tracing out a circular path or a helical path, it’s moving at c. One helical rotation has a longer path length than one circular rotation, so the spin rate is reduced, hence time dilation. It’s a circular form of the simple inference of time dilation on the wiki time dilation page. You’re effectively a collection of spinners, so you don’t notice that a comoving spinner is going round at a reduced rate.