Relativity of Count – Spin Counter

For discussing anything related to physics, biology, chemistry, mathematics, and their practical applications.

Moderator: Flannel Jesus

Re: Relativity of Count – Spin Counter

Postby PhysBang » Fri Sep 17, 2010 2:00 pm

James S Saint wrote:Yeah, I know. I had him on ignore, but even bratty kids say something relevant on extremely rare occasions, so on this new thread, I gave him a chance (again). But guess what. [-(

So that everyone else is clear then: Jimmy is claiming that, although he is making claims about the Lorentz transformations, it is not relevant for him to actually support these claims with the actual use of these equations.
GPS systems correct for time dilation by tracking accelerations (and thus do not use length dilation nor Lorentz).

Every scientific publication on these systems disagrees.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby Farsight » Sat Sep 18, 2010 3:44 pm

James S Saint wrote:Well to sane people, that is obviously true. But the Lorentz equations used to form the Loedel diagrams are taken as "reality". Lorentz presumes a "real" velocity and a time dilation (which is real) thus an relative unreal length.
Yep, people are forever taking mathematical abstraction as reality. I've even had 'em swear blind that a star "really" length-contracts into a discoid when you accelerate towards it.

James S Saint wrote:A transverse spin counter, especially optic, requires that either the time dilation be corrected so as to match "reality" and leave the lengths alone, or we have to accept "relativity of count". Pick your poison. GPS systems correct for time dilation by tracking accelerations (and thus do not use length dilation nor Lorentz).
I go for relativity of count. Then it's quite easy to resolve the pole-and-the-barn length contraction paradox. All you have to do is understand that what you measure is affected by your own motion.
Farsight
Thinker
 
Posts: 528
Joined: Sat Jun 20, 2009 6:24 am

Re: Relativity of Count – Spin Counter

Postby PhysBang » Sat Sep 18, 2010 3:53 pm

Farsight wrote:Yep, people are forever taking mathematical abstraction as reality. I've even had 'em swear blind that a star "really" length-contracts into a discoid when you accelerate towards it.

As you've no doubt been told many times, nobody has ever told you this. You are either grossly mistaken about this despite multiple corrections or you are simply lying about this point. At best you are doing a straw man argument, because it is not the case in relativity theory that one's acceleration causes a star to become oblate. According to relativity theory, the star is already oblate in an infinite number of frames of reference. All acceleration does is change the the frame of reference that we use to describe an object.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby James S Saint » Sat Sep 18, 2010 6:50 pm

Haha.. and if we close our eyes, they no longer exist at all. "Reality is only perception" (straight from the Quantum Magi). :roll:

And I rewrote the OP with a simpler explanation and corrected the use of an inline material spinner.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby PhysBang » Sat Sep 18, 2010 7:25 pm

James S Saint wrote:Transverse Spin Counter
If we mount a transverse spin counter on the train and count the number of transverse spins during the train’s 1000 meter run, the Lorentz equations will yield the same number of spins as anyone at the station would count for that same length of time, especially if it is optic, because transverse time isn’t effected by linear motion and certainly optic time isn't. The spin counter would correct for the time dilated slower clock and measure the correct velocity.

These claims about a "transverse spin counter" are pure fantasy. Presumably these things spin a number of times dependant on the time in their rest frame, which is different than the time in other frames.

Again, despite all these claims that Jimmy makes, he never actually uses the Lorentz transformations he claims to be criticizing.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby James S Saint » Sat Sep 18, 2010 10:35 pm

PhysBang wrote:
James S Saint wrote:Transverse Spin Counter
If we mount a transverse spin counter on the train and count the number of transverse spins during the train’s 1000 meter run, the Lorentz equations will yield the same number of spins as anyone at the station would count for that same length of time, especially if it is optic, because transverse time isn’t effected by linear motion and certainly optic time isn't. The spin counter would correct for the time dilated slower clock and measure the correct velocity.

These claims about a "transverse spin counter" are pure fantasy. Presumably these things spin a number of times dependant on the time in their rest frame, which is different than the time in other frames.

Again, despite all these claims that Jimmy makes, he never actually uses the Lorentz transformations he claims to be criticizing.

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.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby PhysBang » Sun Sep 19, 2010 12:42 am

James S Saint wrote:
PhysBang wrote:
James S Saint wrote:Transverse Spin Counter
If we mount a transverse spin counter on the train and count the number of transverse spins during the train’s 1000 meter run, the Lorentz equations will yield the same number of spins as anyone at the station would count for that same length of time, especially if it is optic, because transverse time isn’t effected by linear motion and certainly optic time isn't. The spin counter would correct for the time dilated slower clock and measure the correct velocity.

These claims about a "transverse spin counter" are pure fantasy. Presumably these things spin a number of times dependant on the time in their rest frame, which is different than the time in other frames.

Again, despite all these claims that Jimmy makes, he never actually uses the Lorentz transformations he claims to be criticizing.

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.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby James S Saint » Sun Sep 19, 2010 4:21 am

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

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

Put up or shut up.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Farsight » Sun Sep 19, 2010 1:09 pm

PhysBang wrote:
Farsight wrote:Yep, people are forever taking mathematical abstraction as reality. I've even had 'em swear blind that a star "really" length-contracts into a discoid when you accelerate towards it.
As you've no doubt been told many times, nobody has ever told you this. You are either grossly mistaken about this despite multiple corrections or you are simply lying about this point. At best you are doing a straw man argument, because it is not the case in relativity theory that one's acceleration causes a star to become oblate. According to relativity theory, the star is already oblate in an infinite number of frames of reference. All acceleration does is change the the frame of reference that we use to describe an object.
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.
Farsight
Thinker
 
Posts: 528
Joined: Sat Jun 20, 2009 6:24 am

Re: Relativity of Count – Spin Counter

Postby James S Saint » Sun Sep 19, 2010 8:58 pm

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.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby PhysBang » Sun Sep 19, 2010 11:41 pm

James S Saint wrote:
PhysBang wrote:Why should I be the one doing your work for you? You are the one who is trying to actually criticize SR.

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

Put up or shut up.

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.
Last edited by PhysBang on Mon Sep 20, 2010 12:01 am, edited 1 time in total.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby Liteninbolt » Mon Sep 20, 2010 12:01 am

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.
Liteninbolt
Philosopher
 
Posts: 3312
Joined: Fri Oct 26, 2007 2:15 pm

Re: Relativity of Count – Spin Counter

Postby PhysBang » Mon Sep 20, 2010 12:03 am

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.
PhysBang
Thinker
 
Posts: 653
Joined: Wed Jul 08, 2009 5:37 pm

Re: Relativity of Count – Spin Counter

Postby James S Saint » Mon Sep 20, 2010 3:14 am

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.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Liteninbolt » Mon Sep 20, 2010 3:41 am

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.
Liteninbolt
Philosopher
 
Posts: 3312
Joined: Fri Oct 26, 2007 2:15 pm

Re: Relativity of Count – Spin Counter

Postby Carleas » Mon Sep 20, 2010 9:52 pm

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.)
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
 
Posts: 4221
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA

Re: Relativity of Count – Spin Counter

Postby James S Saint » Tue Sep 21, 2010 12:34 am

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 Physics
Modern 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 :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Carleas » Tue Sep 21, 2010 4:16 pm

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___________________________________
James S Saint wrote:it doesn't really even appear flattened

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.
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
 
Posts: 4221
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA

Re: Relativity of Count – Spin Counter

Postby James S Saint » Tue Sep 21, 2010 5:37 pm

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
Transverse Spin Non-Dilation.jpg (82.03 KiB) Viewed 501 times
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Carleas » Tue Sep 21, 2010 9:20 pm

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.
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
 
Posts: 4221
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA

Re: Relativity of Count – Spin Counter

Postby James S Saint » Wed Sep 22, 2010 3:00 am

Carleas wrote: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.
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Carleas » Wed Sep 22, 2010 3:08 am

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?

James S Saint wrote:The spinner doesn't change spin speed just because it was pushed along its axis.

It doesn't "change spin speed", but it's not really spinning, is it? A photon is traveling in a circle.
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
 
Posts: 4221
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA

Re: Relativity of Count – Spin Counter

Postby James S Saint » Wed Sep 22, 2010 3:53 am

Carleas wrote: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.

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.

Carleas wrote: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?

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.

Carleas wrote:
James S Saint wrote:The spinner doesn't change spin speed just because it was pushed along its axis.

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

Emm.. is there a relevant difference?
Clarify, Verify, Instill, and Reinforce the Perception of Hopes and Threats unto Anentropic Harmony :)
Else
From 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.
Devil's Motto: Make it look good, safe, innocent, and wise.. until it is too late to choose otherwise.

The Real God ≡ The reason/cause for the Universe being what it is = "The situation cannot be what it is and also remain as it is".
.
James S Saint
ILP Legend
 
Posts: 17878
Joined: Sun Apr 18, 2010 8:05 pm

Re: Relativity of Count – Spin Counter

Postby Carleas » Wed Sep 22, 2010 2:44 pm

James S Saint wrote: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.

James S Saint wrote: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.

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.
User Control Panel > Board preference > Edit display options > Display signatures: No.
Carleas
Magister Ludi
 
Posts: 4221
Joined: Wed Feb 02, 2005 8:10 pm
Location: Washington DC, USA

Re: Relativity of Count – Spin Counter

Postby Farsight » Wed Sep 22, 2010 3:07 pm

You've got it Carleas.

James S Saint wrote:...The spinner doesn't change spin speed just because it was pushed along its axis.
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.
Farsight
Thinker
 
Posts: 528
Joined: Sat Jun 20, 2009 6:24 am

PreviousNext

Return to Science, Technology, and Math



Who is online

Users browsing this forum: No registered users