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Quote from: Thebox on 23/07/2017 23:31:38The clocks are never out of synchronisation if the clock is being used correctly i.e 1=1If you move one clock relative to another, you will necessarily push them out of synchronisation - the only issue is how much, with faster speeds of movement pushing them out of sync by more.QuoteI understand the distance contractions/expansions would cause an issue in timing, sorry I thought you were trying to still say there was a time dilation.Moving a clock slows its ticking. If you want to drag length-contraction in too, then it reduces the slowing of the ticking (by making it the same no matter which way the clock is aligned), but you still have slowed ticking while the clock's moving.
The clocks are never out of synchronisation if the clock is being used correctly i.e 1=1
I understand the distance contractions/expansions would cause an issue in timing, sorry I thought you were trying to still say there was a time dilation.
Quote from: Thebox on 23/07/2017 23:31:38The clocks are never out of synchronisation if the clock is being used correctly i.e 1=1If you move one clock relative to another, you will necessarily push them out of synchronisation - the only issue is how much, with faster speeds of movement pushing them out of sync by more.
So, I can measure the 1 way speed of light by extrapolation of the speed as I move the clocks slower
When you move a clock it is not measuring the speed of light.
Measuring the speed of light is when I measure the time it takes for light to travel through a known distance- from 1 clock to the other."All clocks tick at the same rate at sea level."Moving ones don't.That's the whole damned point.
Quote from: Bored chemist on 24/07/2017 10:46:10So, I can measure the 1 way speed of light by extrapolation of the speed as I move the clocks slowerWhen you move a clock it is not measuring the speed of light. It is measuring the distance light travels through space. Speed does not matter on the Earth from the continental drift to a light beam. All clocks tick at the same rate at sea level. Simultaneity of relativity does not consider time of movement a factor. Frequency of light does not change the speed of light but it does affect the tick rate of a clock. This affect causes clocks to measure distance indirectly as simultaneity of relativity.
But speed between clock positions does not affect the difference in reading on the moved clock.
the only issue is how much, with faster speeds of movement pushing them out of sync by more.
Imagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all.
If we move the clocks out more slowly, we allow them to tick while they're moving, and the slower we move them out to their destinations, the less far behind they will lag in their ticking behind the central clock, but there will always be a lag. The two outer clocks will be synchronised with each other though without any such lag, so that should give you a clue as to a better method for synchronising clocks - if you're using two of them, you have to move both of them in opposite directions the same distance and at the same speed.
The clocks are not in sync though, because the one that moved fastest through space lags behind the other two,
Quote from: David Cooper on 24/07/2017 17:09:32Imagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all. That is impossible if you understand relativity.
Are we in the solar system? How fast is the solar system spinning? Are we in a galaxy? How fast is the galaxy spinning? Are you going with the spin or against the spin? How do you determine not moving?
Quote from: David Cooper on 24/07/2017 17:09:32The clocks are not in sync though, because the one that moved fastest through space lags behind the other two,Your clock is a measure of distance by distance. One light second distance from rest no matter how fast or how slow will register one second difference. The electron in your clock measures the distance in reduction of tick rate due to further distance for the constant electron to travel through. Electron distance is confounded with the distance the light goes through.
Imagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all. We press the button, then we send two of the clocks away in opposite directions. If the central clock is not moving through space, the other two clocks will tick more slowly as they are moved through space. TheBox doesn't seem to understand this point, but if you move the clocks at the speed of light they will stop functioning completely while they're being moved, so if you move them one lightsecond of distance away and then leave them there, the two clocks that you've moved will start ticking again, but they're both one second behind the central clock. The two outer clocks are synchronised with each other, but they're not synchronised any more with the central clock.If we move the clocks out more slowly, we allow them to tick while they're moving, and the slower we move them out to their destinations, the less far behind they will lag in their ticking behind the central clock, but there will always be a lag. The two outer clocks will be synchronised with each other though without any such lag, so that should give you a clue as to a better method for synchronising clocks - if you're using two of them, you have to move both of them in opposite directions the same distance and at the same speed.If you can get that idea into your head,
I can get it into my head just fine that your plan to synchronise the clocks won't work because there is a delay (typically the product of the square root of dielectric constant of the insulation on the wires and the distance divided by c IIRC).
So you are not actually synchronising the clocks with the one in the middle- we know there's a delay.The delay may well be the same in each direction but, as you can reduce it to zero by moving them slowly...Adding a 3rd clock doesn't really seem to add anything.
Re " if you move the clocks at the speed of light they will stop functioning completely while they're being moved, "Then don't.
Why choose the state of affairs where the error you introduce is as big as possible?Why not move them slowly so they stay (arbitrarily close to) synchronised?
Imagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all. We press the button, then we send two of the clocks away in opposite directions. If the central clock is not moving through space, the other two clocks will tick more slowly as they are moved through space. TheBox doesn't seem to understand this point,
Quote from: DavidImagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all. We press the button, then we send two of the clocks away in opposite directions. If the central clock is not moving through space, the other two clocks will tick more slowly as they are moved through space. TheBox doesn't seem to understand this point, Of course I understand this point and I also understand this point to be incorrect which you do not.
Let me take three light clocks , the distance between the mirrors on clock one is a Planck length . the distance between the mirrors on clock two is 1 mm the distance between the mirrors on clock three is 1cm Oh look I have just created different tick rates by adding distance the light has to travel between ticks.
Let us start again and measure time correctly. I have again 3 light clocks, the distance between the mirrors on clock one is a Planck length . the distance between the mirrors on clock two is a Planck length the distance between the mirrors on clock three is a Planck length Oh look we are now synchronous
Sorry for being ''cocky'' David, but quite clearly you do not understand relative correctness.
Quote from: Thebox on 25/07/2017 01:18:01Quote from: DavidImagine three clocks that are sitting together. They are wired together and connected to a button which can be used to synchronise them all. We press the button, then we send two of the clocks away in opposite directions. If the central clock is not moving through space, the other two clocks will tick more slowly as they are moved through space. TheBox doesn't seem to understand this point, Of course I understand this point and I also understand this point to be incorrect which you do not.The "this point" in the bit you've quoted points forwards to the rest of the content of the same sentence where the point is made much more clearly for you - if you could move the clocks at the speed of light, they would stop ticking altogether (while being moved). If you move them at a little bit less than the speed of light they may struggle to complete a single tick while being moved. The slower you move them, the more quickly they will tick while being moved, but they will always be ticking more slowly than the stationary clock while they are moving. I've shown you the proof of this a multitude of times in another thread and you stubbornly refuse to accept it, even though you seemed to agree with every step of the argument along the way, so it's entirely a matter of you having a belief which you are not prepared to part with no matter how much it is shown to be wrong, and there's no fix for that.QuoteLet me take three light clocks , the distance between the mirrors on clock one is a Planck length . the distance between the mirrors on clock two is 1 mm the distance between the mirrors on clock three is 1cm Oh look I have just created different tick rates by adding distance the light has to travel between ticks.And moving a clock will increase the communication distances too.QuoteLet us start again and measure time correctly. I have again 3 light clocks, the distance between the mirrors on clock one is a Planck length . the distance between the mirrors on clock two is a Planck length the distance between the mirrors on clock three is a Planck length Oh look we are now synchronousAnd now you've just introduced a length-contraction much stronger than the one that everyone else accepts, and you've added a width-contraction to it too! But you won't recognise that because you're a magical thinker.QuoteSorry for being ''cocky'' David, but quite clearly you do not understand relative correctness.If you base your physics in magic, that's entirely up to you, but it means you're just one more artist making Turner-Prize-winning works out of elephant dung.
if you could move the clocks at the speed of light, they would stop ticking altogether
But all the slowed ticking means is the timing mechanism is out of synchronisation, there is no actual physical length contraction, there is just more or less distance the light has to travel from or . This in no way affects the rate of time it affects the rate of timing. It is not much difference to when a timing belt slips and a car misfires.
Aha!Progress!Imagine that I repeat the thought experiment I did earlier (the one where I was carrying a clock round on a bicycle).I repeat it several times, but I use different modes of transport..With a space ship, the difference between the "expected" value for m and 10,000 is larger tan when I use a jet plane.And that, in turn is bigger than when I use a bike.The version where I uses continental drift to move the clocks gives a result even closer to 10,000.So, I can measure the 1 way speed of light by extrapolation of the speed as I move the clocks slower.In the limit I can calculate it for moving the clocks at zero speed.Is there any reason to suppose that, if I did that, the limiting value I would get for the 1 way speed of light was any different from C?
If you move one clock relative to another, you will necessarily push them out of synchronization - the only issue is how much, with faster speeds of movement pushing them out of sync by more.
The clocks only become out of synchronisation because they are not very good clocks.
no, you are measuring time by counting at different speeds which is wrong.
What? Why?
Quote from: David Cooper on 23/07/2017 23:55:45If you move one clock relative to another, you will necessarily push them out of synchronization - the only issue is how much, with faster speeds of movement pushing them out of sync by more...No, you can accelerate two synchronized clocks from the same location in opposite directions with the same amount of acceleration.
If you move one clock relative to another, you will necessarily push them out of synchronization - the only issue is how much, with faster speeds of movement pushing them out of sync by more...
Quote from: Bored chemist on 24/07/2017 21:50:57I can get it into my head just fine that your plan to synchronise the clocks won't work because there is a delay (typically the product of the square root of dielectric constant of the insulation on the wires and the distance divided by c IIRC).How are you synchronising them then when you have two clocks together? Are you pressing buttons on both of them and getting an error of up to a tenth of a second instead of using one button to start both? I can assure you that my way of doing it is more accurate. The big question though is about getting clocks synchronised at a distance and the errors that necessarily find their way into that, so the trivial business of how synchronising clocks at a single location is done is a trivial sideshow.QuoteSo you are not actually synchronising the clocks with the one in the middle- we know there's a delay.The delay may well be the same in each direction but, as you can reduce it to zero by moving them slowly...Adding a 3rd clock doesn't really seem to add anything.I brought the third clock into this to try to help you see how awful your synchronisation method is. If you synchronise the three clocks at the central location, you can then move two of them away from there in opposite directions at the same speed to get them where you want them to be. Those two clocks are now as just about as well synchronised with each other as they can be, but only if the system happens to be stationary rather than moving fast through space. The middle clock though is badly synchronised with them, and the faster you moved the other two clocks into position, the worse the synchronisation with the middle clock will be. You only have two clocks, and one of them is being treated like my middle clock, so you're getting the huge error in your synchronisation instead of the minimal error with my two outer clocks. If you know how fast you moved your moving clock relative to your stationary clock though, you can adjust the timing of one or other of them to correct that synchronisation, at which point your clocks can be just as well synchronised as my pair of moved clocks. In both cases though, even that superior synchronisation will be affected by the movement of the system through space, so one clock's time may be far ahead of the other, which is why when you use them to attempt to measure the one-way speed of light, you are guaranteed to get the value c regardless of the actual speed of the light that you're timing relative to the system.QuoteRe " if you move the clocks at the speed of light they will stop functioning completely while they're being moved, "Then don't.Imagine a light clock aligned with the direction you're moving it in. If you move this clock at c, the clock will stop clicking throughout the time you're moving it because the light would have to travel faster than c in order to complete a circuit (and thereby to tick). All clocks are limited in the same way, slowed to the same extent by their movement through space.QuoteWhy choose the state of affairs where the error you introduce is as big as possible?Why not move them slowly so they stay (arbitrarily close to) synchronised?The faster you move your only moved clock into position, the sooner you can start using your clocks to make measurements. It would be stupid to take a million years to move your clock into position just to minimise a predictable error which you can simply adjust for. That error is a complication which you want to eliminate, and it's a diversion away from the nature of the real error that you cannot correct for - the undetectable error affects all methods of synchronisation and it affects them equally. It's caused by the communication delay in one direction being longer than in the opposite direction if the system is moving through space.
OK, these are those nice clocks you find in thought experiments.You can synchronise them however you like, including the button on the top.If they are next to each other then here's an amusing way to do it.Turn one of the clocks upside down.Press its button down on the button of the other clock.Since both presses are the same event they are necessarily synchronised exactly.
It's a thought experiment we don't worry about irrelevant issues like whether my reflexes are good enough to press two buttons in a tenth of a second or what.
Because the two clocks are next to each other it's perfectly simple to synchronise them. Relativity doesn't have any problems with "at the same time" for things that are "in the same place".
Now, do you see that my "awful" synchronisation method is (at the time when I'm synchronising them) actually mathematically perfect?You can see how no observer anywhere in the universe, regardless of their speed, acceleration of local gravity will ever see the two clocks -just after I push both buttons in the same place and at the same time- as being anything other than synchronised?
That's why I choose to set the clocks running at zero in the same place and at the same time.From the point of view of nearly everybody else in the universe, your "synchronised clocks" are ( or at least may be) never in step because they are separate in space.With my approach, once we have two clocks that at least start out together we can run the experiment where we know how far out of synch the clocks are (because we can calculate it from the way in which we moved one of them).And we can minimise that change.
We can make it as small as we like (by moving them a short distance and/ or slowly).
And then we have two nearly synchronised clocks which we can set off a flash lamp in front of and look at the delay.