roineust
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Hey ghwellsjr,
Yes, Please.
Roi.
Yes, Please.
Roi.
There is actually no need to use time dilation in the explanation of the null result of MMX, since the measurement was just based on whether waves remained in phase and there was no testing of the total amount of time they took to travel up the interferometer arm and back.ghwellsjr said:Roi, chances are those classes did not teach how Lorentz explained the null result of MMX using Length Contraction and Time Dilation. It can be done purely graphically with very little math. Would you like me to walk you through this exercise?
No one said your idea contradicted energy conservation, Vanadium said it an absolute time clock is 'the SR equivalent of the Newtonian "A Perpetual Motion Machine!"', which just means that it is analogous in the sense that it is as basically impossible in an SR context as perpetual motion is in Newtonian physics (and perhaps also in the sense that both hold a persisting appeal to physics cranks).roineust said:Can someone explain to me why diagram 2 depicts a contradiction with the laws of energy conservation (a 'perpetum mobilum’)?
Which part of what I said are you not sure about? The only uncertain issue is whether the fundamental laws of physics will ultimately turn out to be Lorentz-invariant, but it's certainly true that the most accurate equations found so far are, and that it's a guaranteed theoretical truth that if all the fundamental laws of physics are Lorentz-invariant then all clocks governed by these laws will show time dilation and an "absolute time clock" must be impossible.roineust said:JesseM,
You might be right. I don't know.
Roi.
ghwellsjr said:Roi, chances are those classes did not teach how Lorentz explained the null result of MMX using Length Contraction and Time Dilation. It can be done purely graphically with very little math. Would you like me to walk you through this exercise?
roineust said:Hey ghwellsjr,
Yes, Please.
Roi.
The act of setting the time on the distant event time recording device will result in getting whatever answer you want when you "make" this measurement. If you follow Einstein's method for setting the time on your distant device, then you will determine that your frame has no motion--that's exactly what Special Relativity is all about.Ymyk said:What if, in the simplest form that the recorded time of emission of a pulse of light directed at one mirror at the far end of the train where this mirror has event time recording capabilities also, that is when the time of light arrival is recorded and imbeded in the return/reflected signal. Then the distance of light travel of the outbound and inbound trajectories can be calculated, or it appears so (let C=1 a unit SOL). If both trajectories are equal the attached frame has no motion, otherwise, the frame is moving. I do not intend to divert the direction of this very interesting thread and I only came upon it by accident, having just registered in early December.
There has to be a simple correction to this simplistic intervention.
ghwellsjr said:The act of setting the time on the distant event time recording device will result in getting whatever answer you want when you "make" this measurement. If you follow Einstein's method for setting the time on your distant device, then you will determine that your frame has no motion--that's exactly what Special Relativity is all about.
Good.roineust said:ghwellsjr,
So far so good,
Please continue.
Roi.
ghwellsjr said:Ymyk, it is very difficult to understand your scenario. It appears that you are using some of your nomenclature to refer to absolute times (A0, Bu, A2?) and others for delta times (B1). But whatever you are doing, it is not legitimate. You cannot measure the one-way speed of light. You cannot tell how long it takes for light to go from A to B or B to A without some previously defined answer to the question. I'm sure that transponders are relying on a previously defined timing conventions and so cannot be used to measure the times of receipt/reflection as you are proposing. You should be able to figure out what is wrong with your idea if you understand Special Relativity. In fact, you wouldn't even attempt to find a way around the problem. You do realize that if what you are proposing is legitimate, that you have just dethroned Einstein and you will be able to take his seat. Is that what you really believe?
And how did you already know the SOL? You assumed it, that is what AE did.Ymyk said:You made a great deal claiming that I couldn't measure the one way sol. I didn't try to measure the sol. I already knew the sol as approximately 3x 10^8 km/sec which IO copied out of AE's book "relativity".
Ymyk said:ghwellsjr, My clumsy language perhaps garbled what is a simple arrangement. Two tranbsponder are separated by a constant distance. A transponder is a device that substitutes fro air traffic control radar. Insted of bouncing the outbound sihnal off of an aircraft, the signal is coded and the 'reflected signal' has the time of arrival and reflection imbeded in the return signal - aircraft ID, azimuth and elevation and calculated distance are included.
The transponders are identical in all respects. My argument is straightgforward. A0 is the time imbeded in the outbound pulse in the direction of the B transponder. At A0 the B clock is unknown, or Bu, a recordwed vcalue. When the pulse arrives at B the B clock registers Bu + B1 , where both Bu and B1 are unbknown but their total clock value is recorded when the pulse arrives. In other words the pulse simple tells the clock to give out the current clock time, he Bu + B1. When the pulse returns to A at A2, the B clock now reads Bu + A2, again recorded as x1. Immediately emitting a pulse from A where the clock now is A2, arrives at B at Bu + A2 + B1 = x2 subtracting thye two x's x2 - x1 = Bu + A2 + B1 - Bu - A2 = B1, which is the time of flight of the pulse from A to B. There is no measure of the SOL which is presumed to be constant at unit SOL C = 1.
The two clock are ticking at the same rate and even thoughn there was initially no information of what the clock time on B happened to be when the A clock reas A0.
There is also the presumption that the motion of the [pulse is independent of the motion of the source of the light - I already knew what the SOL was before the pulse motions began.
The repeat of the round tripm trajectory was intended for the purpose of determining what the instantaneous clock time difference of the two transponders happened to be.
The transponders work as I have indicatedbut I am sure that the system disrfegards any relativity effects for the reason thagt the velocities are soi slow.
Look at it as two clocks separated by a constant distance. On clock emits a pulse at A0 when the B clock time is inknown or Bu, a time recorded when triggered by the arriving pulse.
We don't even need to imbed the time of arrival in the reflected pulse. As long as the A transponder has the A0 and A2 times recorded and the B clock has the Bu + B1 time recorded. Calculating the trajectory distances is then trivial and can be accomplished at the observer's pleasure.
You made a great deal claiming that I couldn't measure the one way sol. I didn't try to measure the sol. I already knew the sol as approximately 3x 10^8 km/sec which IO copied out of AE's book "relativity". AE didn't know about transponders in 1905.
I didn't violate any relativity concept. In fact I claim that determining the velocity of the transponder is determined soley from the three time-of -day events A0, A2, and B1. Which is NOT a measurement of the velocity NOR detection of motion. The three event times are carefully recorded.
ghwellsjr said:OK, good. Now the first thing we must do is put ourselves in the mindset of most of the great scientists of that era. They believed in an absolute ether rest frame in which light propagated at the same constant speed in all directions. Imagine a very brief bright flash of light being set off in this stationary frame. It will create an ever-expanding spherical shell of light, centered on its point of origin with respect to the stationary ether.
ghwellsjr said:They believed that if the source of light were moving with respect to this stationary ether frame, the source would not remain in the center of this expanding spherical shell but would move off-center.
ghwellsjr said:But the question is: how can we tell if the light source remains in the center of this expanding shell or moves off-center? By analogy, we could visualize what would happen if we were observing an expanding ring of waves on the surface of a pool after dropping a pebble in the water because we use light to observe the water, but how can we observe a lightwave once it has started moving away from us? Therein lies the problem: we cannot directly observe the propagation of light so we do the next best thing which is to set up an array of mirrors to reflect the light back to us.
Now the best way to "observe" an expanding spherical shell of light is to set up a whole bunch of mirrors, all an equal distance from the source and in all possible directions. Then when we set off the flash it will expand until it simultaneously hits all the mirrors which turn the expanding spherical shell of light into a contracting spherical shell of light which will eventually collapse on the source simultaneously from all directions.
For purposes of illustration, we will consider a two-dimensional subset of mirrors and an expanding ring of light, much like the expanding ring of waves on the surface of a circular pool of water as it simultaneously strikes the entire pool wall circumference, reverses direction and simultaneously collapses on the source in the center of the pool.
ghwellsjr said:I realize this is pretty simple so far, but I want to make sure you grasp all the concepts before moving on so if there is anything that is ambiguous or confusing, please let me know before we continue.
ghwellsjr said:Now it's really not practical to build a solid sphere of mirrors but all we really need is four mirrors that are placed 90 degrees apart and all equidistant from the observer. In this animation, I have used circular mirrors so that when the light strikes them, they create a new expanding circle of light.
I represent the stationary observer in green and I call him Homer (think green, green grass of home). I represent the original expanding circle of light in blue as well as a blue dot to represent its source, the mirrors in brown, the collapsing circles of light in green when they reflect off stationary mirrors.
Please note that just as in the previous post when the collapsing circle of light arrived simultaneously from all directions on the observer, the four reflections from the four mirrors all arrive simultaneously on the observer. Although this is not actually how the MMX was configured, it still represents conceptually exactly what the experiment was doing.
The MMX experimenters assumed that the previous animation would represent only what would happen if they were stationary with respect to the ether which they believed they never were. They believed that they were constantly moving with respect to the ether and also constantly changing their velocity through the ether as the Earth rotated on its axis and as it revolved around the sun. This constant acceleration was very small so for all practical purposes, they could assume that they were moving at a constant speed through the ether. This is how they thought the light would behave:
I represent the moving observer in red and I call him Rover (think Red Rover). The light that reflects off the moving mirrors is shown in red and a red dot is placed at the origin of each expanding reflection.
Note that when the light from the four mirrors arrives at Rover, it is not simultaneous, it first arrives from the top and bottom mirrors and then later arrives from the left and right mirrors. This is what the MMX experimenters expected to measure but instead, they got the same result as if they were stationary in the ether, the same result the Homer would have gotten.
So now the question is how can this happen? Well, Lorentz and others came up with an explanation and we will go through a process that will arrive at the same explanation.
First, we want to learn how we know where to put the mirrors so that the expanding circle of light can create a reflection that results in a collapsing circle of light in just the right place at just the right time. For Homer, it's easy:
Just note the intersection of the blue expanding circle and the green collapsing circle and in this animation, we draw a black dashed line to show where that intersection occurs:
Now for Rover, it's a little more complicated because his collapsing circle of light is not centered on the expanding circle of light but rather the location of where he will be later on, shown as a red dot. Try to visualize in this animation where the blue and red circles intersect:
And here we have the black dashed line to show the points of reflection:
Now this black dashed line shows the points of relection relative to the ether but we really want them relative to Rover, so here we show both for comparison:
Also, note that Lorentz realizes that everything contracts in the direction of motion so we now show Rover as being length contracted as well as his circular arrangement of mirrors. In addition, the time it takes for the light to traverse from Rover to the mirrors and back to Rover is longer than it was for Homer which illustrates time dilation. We can also see the issue of Relativity of Simultaneity because the reflections for Rover do not all occur at the same time whereas they do for Homer.
This illustrates how Lorentz believed MMX produced the null result. He believed that the experiment was moving through the ether and experienced length contraction, time dilation and relativity of simultaneity.
He also believed that Rover would measure the speed of light to be the same as Homer because even though time was going slower and stretching out (time dilation), it is the actual length that the light has to travel relative to the ether that is used to calculate the speed (length divided by time), so we need to use the lengths defined by the black dashed line, not the moving brown line representing the length contracted mirror. This length is dilated to the same extent that time is dilated and so the two dilations cancel each other out and give the same calculation for the speed of light.
However, Einstein put a new spin on the interpretation. He said that we could assume that MMX was actually stationary in the ether and everything else that was moving with respect to MMX was experiencing length contraction, time dilation and relativity of simultaneity.
I'm not sure I understand your concern. Roi is the one who is trying to design an absolute clock which is the same as trying to identify an absolute ether rest frame. I'm trying to show him historically how Special Relativity treats each Frame of Reference as if it were an absolute ether rest frame, just so that he can understand SR. I believe that once a person understands how time dilation, length contraction and relativity of simultaneity work in explaining the null result of MMX in the context of the existence of ether, and how SR is merely a switch in concept where instead of the ether being out there somewhere unknown, we can treat it as if it is any inertial frame of reference, they will no longer search for the ether any more or search for a means to make an absolute time clock.nismaratwork said:This is an explanation I think I'll modify for use with family members on this issue. Thanks ghwelljr, your posts are always very thoughtful.
Quick question... what's the point of trying to design a clock (I realize you're arguing against it, not for it) to measure something that modern physics tells us is NOT absolute and universal? I must be missing something critical... I thought that one of the central tenants of relativity was the inability to define the passage of time in absolute terms for anything other than an ether?
This thread seems like a backwards argument to get to that absolute frame of reference, but using time as the hook instead of relative motion.
ghwellsjr said:I'm not sure I understand your concern. Roi is the one who is trying to design an absolute clock which is the same as trying to identify an absolute ether rest frame. I'm trying to show him historically how Special Relativity treats each Frame of Reference as if it were an absolute ether rest frame, just so that he can understand SR. I believe that once a person understands how time dilation, length contraction and relativity of simultaneity work in explaining the null result of MMX in the context of the existence of ether, and how SR is merely a switch in concept where instead of the ether being out there somewhere unknown, we can treat it as if it is any inertial frame of reference, they will no longer search for the ether any more or search for a means to make an absolute time clock.
I have more animations to show how Homer and Rover both think they are in the center of the expanding circle of light and how they each see that the other one also thinks he is in the center, but I want to let this one sink in first.
ghwellsjr said:No, there might be a momentary shift in the color of the light (frequency) during the acceleration but as soon as the effect of that is over, the detected light and the unboard clock behave just like they did before the acceleration. But you could use this or any number of other means to measure/calculate the speed of the train..
Sure, in principle it is possible to take an accelerometer, a clock, and a computer and build a device which accounts for relativistic effects and measures coordinate time. That is essentially what GPS does. Such a device would confirm relativity.NoDoubt said:I can put another experiment to show that it is possible to build a clock that will not loose its time because of motion, In simple words, A clock that will keep time with my home clock, no matter what, even if you put it on a jet, a rocket, or any thing faster than that. It should keep its time.
But as I said before:NoDoubt said:Alright, alright, I agree with you.
So do you agree with me that this arrangement will work only while acceleration, but not in constent velocity situation? If yes, I can put another experiment to show that it is possible to build a clock that will not loose its time because of motion, In simple words, A clock that will keep time with my home clock, no matter what, even if you put it on a jet, a rocket, or any thing faster than that. It should keep its time. I'll give it a try, may be I'm missing something?
Your home clock is not an absolute clock. And you don't need to actually construct a clock to keep track of Earth time, you can do it with Lorentz Transforms as long as you keep track of your accelerations. But even then, you have to be aware that even Earth time is not unique except to those stationary on earth. From any other reference frame, time is totally different.ghwellsjr said:An Absolute clock is considered one that is stationary in the so-called, presumed, universal, at-rest ether which no one knows how to identify if it were to exist and so there is no hope to have an Absolute clock.
ghwellsjr said:Your home clock is not an absolute clock. ?
ghwellsjr said:Would you also try to have a clock on Earth keep track of the time on a clock on the moving spacecraft and consider that significant?
So please try to explain your point.NoDoubt said:I'm sorry, You missed the whole point.
But your first post on this thread started off:NoDoubt said:Of cource, I know that.ghwellsjr said:Your home clock is not an absolute clock.
And then you proceeded to propose something that I thought was supposed to be an Absolute time clock. Did you change your mind somewhere along the line without telling us? Please be clear and state what it is you are trying to do here.NoDoubt said:All we are trying to build is an Absolute time clock, let's follow the rules of Physics and see if it works...
ghwellsjr said:But your first post on this thread started off:
And then you proceeded to propose something that I thought was supposed to be an Absolute time clock. Did you change your mind somewhere along the line without telling us? Please be clear and state what it is you are trying to do here.