1 Gary Harnagel | Galilean transformation equations and Robert B. Winn | Monday 26 june 2017 |
2 Nicolaas Vroom | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
3 Gary Harnagel | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
4 mlwo...@wp.pl | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
5 Nicolaas Vroom | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
6 Paparios | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
7 Gary Harnagel | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
8 Jim Petroff | Re :Galilean transformation equations and Robert B. Winn | Tuesday 27 june 2017 |
9 tjrob137 | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
10 mlwo...@wp.pl | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
11 Nicolaas Vroom | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
12 Gary Harnagel | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
13 Nicolaas Vroom | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
14 ldz...@gmail.com | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
15 ldz...@gmail.com | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
16 ldz...@gmail.com | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
17 ldz...@gmail.com | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
18 tjrob137 | Re :Galilean transformation equations and Robert B. Winn | Wednesday 28 june 2017 |
19 tjrob137 | Re :Galilean transformation equations and Robert B. Winn | Saturday 1 july 2017 |
20 Buck Millard | Re :Galilean transformation equations and Robert B. Winn | Sunday 2 july 2017 |
21 danco...@gmail.com | Re :Galilean transformation equations and Robert B. Winn | Sunday 2 july 2017 |
22 Gary Harnagel | Re :Galilean transformation equations and Robert B. Winn | Tuesday 11 july 2017 |
Galilean transformation equations and Robert B. Winn.txt
258 posts by 22 authors
https://groups.google.com/forum/?fromgroups=#!topic/sci.physics.relativity/5nin6WJBzwQ%5B176-200%5D
> |
On Sunday, June 25, 2017 at 8:19:57 PM UTC-7, Gary Harnagel wrote: |
> > |
On Sunday, June 25, 2017 at 8:45:59 PM UTC-6, Robert Winn wrote: |
> > > |
Einstein definitely said he had a slower clock. |
> > |
No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
> > > |
I have to agree with him. |
> > |
Then you are wronger than he was. He had an excuse, YOU don't. |
> > > |
The moving clock was slower. |
> > |
No, it wasn't. You are BADLY mistaken. Scientists today KNOW better. YOU are decades out of date. The world of science has moved on, yet there you sit in your jockies pretending that you're smarter than everyone else. You're not. “Being ignorant is not so much a shame, as being unwilling to learn.” -- Benjamin Franklin “Talk no more so exceeding proudly; let not arrogancy come out of your mouth” – 1 Samuel 2:3 “A fool is someone whose arrogance is only surpassed by his ignorance.” ? Orrin Woodward |
> |
Orrin Woodward? Now you are taking a name in vain. |
No, I'm not. He described YOU quite accurately.
> | I sell books for Orrin Woodward. |
He might not let you if he found out how arrogant, ignorant and dishonest you are.
> | Orrin Woodward has a degree in engineering. Do you think he is going to agree with Einstein? |
I have a degree in engineering and I don't agree with YOU :-)
> | But anyway, how would you like to get out of debt? |
I'm not in debt.
> | make more money? |
I'm doing okay.
> | pay less taxes? |
That's "Pay less TAX." The plural implies the amount is individual, countable monetary units, so you should say, "Pay FEWER taxes."
> | I can sell you the Green Box for $120 and get you started on the road to financial freedom. |
Is that why you're living in a trailer on a ranch in Arizona?
> | On Sunday, June 25, 2017 at 8:45:59 PM UTC-6, Robert Winn wrote: |
> > |
On Sunday, June 25, 2017 at 6:00:20 PM UTC-7, Gary Harnagel wrote: |
> > > |
> > > > |
only accurate clocks and inaccurate clocks. So how do you think Einstein came to have a slower clock? |
> > > |
He probably bought it at Walgreens, like YOU did. |
> > |
No, I think you are wrong about that. |
> |
You are the one in error, mon ami. And Einstein was wrong about moving clocks running slow. Didn't you get the memos? They've been floating around here for quite some time. |
Somewhere along the line I'am missing something. Can some one give me a link to the memos mentioned?
> > | Einstein definitely said he had a slower clock. |
> |
No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. That means during the time that clock B travelled (away and back) clock B did run slower than clock A. To describe this phemomena (experiment) IMO the wording APPEAR is wrong.
Nicolaas Vroom
> |
On Monday, 26 June 2017 05:19:57 UTC+2, Gary Harnagel wrote: |
> > |
On Sunday, June 25, 2017 at 8:45:59 PM UTC-6, Robert Winn wrote: |
> > > |
On Sunday, June 25, 2017 at 6:00:20 PM UTC-7, Gary Harnagel wrote: |
> > > > |
> > > > > |
only accurate clocks and inaccurate clocks. So how do you think Einstein came to have a slower clock? |
> > > > |
He probably bought it at Walgreens, like YOU did. |
> > > |
No, I think you are wrong about that. |
> > |
You are the one in error, mon ami. And Einstein was wrong about moving clocks running slow. Didn't you get the memos? They've been floating around here for quite some time. |
> |
Somewhere along the line I'am missing something. Can some one give me a link to the memos mentioned? |
Too numerous to bother with. Just ask your questions.
> > > | Einstein definitely said he had a slower clock. |
> > |
No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
> |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
Yes, it is running at the same rate as A, but it is behind.
> | That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
But you have no way of directly determining that. You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower).
> |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong.
Nicolaas Vroom |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion (which is why A's clock appears to run slower to B).
> | Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. |
So, they have non-identical readings, and that denies your "identical" condition.
> | On Tuesday, June 27, 2017 at 6:52:06 AM UTC-6, Nicolaas Vroom wrote: |
> > |
On Monday, 26 June 2017 05:19:57 UTC+2, Gary Harnagel wrote: |
> > > |
No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
> > |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
> |
Yes, it is running at the same rate as A, but it is behind. |
> > |
That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
> |
But you have no way of directly determining that. |
That is correct if you mean during the time the two clocks were not
at my desk.
After clock B returned and before looking there are three possible answers:
1) They both show the same time.
2) Clock B shows an earlier time and runs behind.
3) Clock A shows an earlier time and runs behind.
In case 2) clock B is considered the moving clock
In case 3) clock A is considered the moving clock
> | You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
I do not see any paradox. This is a physical experiment and it requires a physical explanation.
While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system.
> > | To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
That is "correct" before they meet again.
> | (which is why A's clock APPEARS to run slower to B). |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more.
Nicolaas Vroom.
> | On Tuesday, 27 June 2017 15:50:13 UTC+2, Gary Harnagel wrote: |
> > | Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> |
That is "correct" before they meet again. |
> > |
(which is why A's clock APPEARS to run slower to B). |
> |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. Nicolaas Vroom. |
Consider, for example, the GPS satellite atomic clocks. Before launching, the frequency of those clocks is set to 10.2299999954326 MHz. Then, in your GPS receiver on the ground, the signals received from the GPS satellite are measured to be exactly of 10.23 Mhz. Nothing has changed in the orbiting atomic clock, but on the ground its frequency is measured at 10.23 Mhz, which is the geometrical projection in spacetime from the frequency of the orbiting satellite.
> |
On Tuesday, 27 June 2017 15:50:13 UTC+2, Gary Harnagel wrote: |
> > |
On Tuesday, June 27, 2017 at 6:52:06 AM UTC-6, Nicolaas Vroom wrote: |
> > > |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
> > |
Yes, it is running at the same rate as A, but it is behind. |
> > > |
That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
> > |
But you have no way of directly determining that. |
> |
That is correct if you mean during the time the two clocks were not
at my desk.
After clock B returned and before looking there are three possible answers:
1) They both show the same time. |
A and B cannot get back together again unless one of them changes frames. The one that changes frames will lag the other.
> > | You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
> |
I do not see any paradox. This is a physical experiment and it requires a physical explanation. |
And there is one: one that does not require either clock to actually be running slower.
> | While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system. |
Sure. Not really so difficult after all. Of course, Doppler effects and time delays would have to be taken into account.
> > > | To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> > |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> |
That is "correct" before they meet again. |
Which can't happen unless one of them changes frames.
> > | (which is why A's clock APPEARS to run slower to B). |
> |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. Nicolaas Vroom. |
They will be reading different times, but you still can't assume either of them was "running slow." As Paparios says, it's a geometric projection effect.
> | On Monday, 26 June 2017 05:19:57 UTC+2, Gary Harnagel wrote: |
>> | No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
Yes.
> | Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
OK. That is some incredibly powerful "tool", far beyond what is possible today. But gedankens can invoke such "tools". I assume both clocks are ideal and undamaged.
> | That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
No. The problem is as much in your wording as in your physics, but BOTH are wrong.
Wording: When you say "that clock runs slow", you mention ONLY the clock, and thus cannot impose some OTHER reference, all you can use is the clock ITSELF. And the clock just ticks along at its usual rate. Indeed put a frequency standard right next to it, co-moving with it, and it will show that the clock DOES tick at its usual rate. So moving clocks DO NOT RUN SLOW.
Physics: Your scenario does NOT display "time dilation", it demonstrates a different geometrical phenomenon: different timelike paths through spacetime can have different elapsed proper times. Every clock ALWAYS ticks at its usual rate, regardless of where it might be located or how it might be moved [#]. If you want to compare a moving or distant clock to a clock nearby, you must use SIGNALS from the other clock to this one, and you must consider how those SIGNALS are affected (by the motion or distance) -- do that and you find the ENTIRE effect is due to the way those SIGNALS are measured, leaving "no room" for the clocks to tick at different rates.
The fact that clocks A and B experience different elapsed proper times along their different paths through spacetime is no more remarkable than the fact that for triangle UVW the paths UV and UWV have different lengths. Indeed if your "tool" used instantaneous accelerations and inertial motion between them, your scenario is just a triangle in spacetime, with clock a traveling UV and clock B traveling UWV (U is when they separate, V is when they rejoin, and W is a turn-aound in clock B's path that enables it to come back to clock A).
> | To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
Yes. Say "is measured (in the appropriate inertial frame)" instead. This is not mere appearance, and this effect can and does have real physical consequences (e.g. pion beam lines that are a kilometer long -- in the lab it takes the pions 3.3 microseconds to traverse the beamline, but the pions experience elapsed proper times considerably less than their 26 nanosecond lifetime). There are other, more direct experimental implementations of the "twin paradox"....
Tom Roberts
> | On Tuesday, June 27, 2017 at 8:33:11 AM UTC-6, Nicolaas Vroom wrote: |
> > |
After clock B returned and before looking there are three possible answers: 1) They both show the same time. 2) Clock B shows an earlier time and runs behind. 3) Clock A shows an earlier time and runs behind. In case 2) clock B is considered the moving clock In case 3) clock A is considered the moving clock |
> |
A and B cannot get back together again unless one of them changes frames. The one that changes frames will lag the other. |
Cannot they both change frames? Does not any change in speed implies a change in frame? Anyway what has changing frames to do with this experiment? IMO the most important issue is (in case 2) that clock B must change its speed (direction of speed)
> > > | You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
> > |
I do not see any paradox. This is a physical experiment and it requires a physical explanation. |
> |
And there is one: one that does not require either clock to actually be running slower. |
I do not understand how this explanation explains the outcome of the experiment i.e. that when the two clocks meet their readings are different.
> > | While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system. |
> |
Sure. Not really so difficult after all. Of course, Doppler effects and time delays would have to be taken into account. |
> > > > |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> > > |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> > |
That is "correct" before they meet again. |
> |
Which can't happen unless one of them changes frames. |
If you mean unless at least one changes its speed. In this experiment clock B has at least change its speed twice.
> > > | (which is why A's clock APPEARS to run slower to B). |
> > |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. |
> |
They will be reading different times, but you still can't assume either of them was "running slow." As Paparios says, it's a geometric projection effect. |
Why can not I say that one clock is running slower as the other (while moving)? Such an description is in accordance with the final observation i.e. that the readings are different.
IMO the only lesson learned from this experiment that when you want to understand the laws of nature you should not use clocks which move relatif to each other and if you do then you should adjust the readings of each clock.
Nicolaas Vroom
> |
On Tuesday, 27 June 2017 17:32:03 UTC+2, Gary Harnagel wrote: |
> > |
On Tuesday, June 27, 2017 at 8:33:11 AM UTC-6, Nicolaas Vroom wrote: |
> > > |
After clock B returned and before looking there are three possible answers: 1) They both show the same time. 2) Clock B shows an earlier time and runs behind. 3) Clock A shows an earlier time and runs behind. In case 2) clock B is considered the moving clock In case 3) clock A is considered the moving clock |
> > |
A and B cannot get back together again unless one of them changes frames. The one that changes frames will lag the other. |
> |
Cannot they both change frames? |
Sure, but then one cannot say anything definite without describing exactly how each did so. You would also have to define another frame that remained inertial. Why would you try to insert such complications into a simple statement?
> | Does not any change in speed implies a change in frame? |
Yes (we're discussing SR here).
> | Anyway what has changing frames to do with this experiment? |
It should be obvious that A and B cannot get back together without doing so, and THAT is the crux of the matter (look at a Minkowski diagram of the situation).
> | IMO the most important issue is (in case 2) that clock B must change its speed (direction of speed) |
THAT changes frames.
> > > > | You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
> > > |
I do not see any paradox. This is a physical experiment and it requires a physical explanation. |
> > |
And there is one: one that does not require either clock to actually be running slower. |
> |
I do not understand how this explanation explains the outcome of the experiment i.e. that when the two clocks meet their readings are different. |
Look at a Minkowski diagram: the paths have different lengths.
> > > | While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system. |
> > |
Sure. Not really so difficult after all. Of course, Doppler effects and time delays would have to be taken into account. |
> > > > > |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> > > > |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> > > |
That is "correct" before they meet again. |
> > |
Which can't happen unless one of them changes frames. |
> |
If you mean unless at least one changes its speed. In this experiment clock B has at least change its speed twice. |
Exactly!
> > > > | (which is why A's clock APPEARS to run slower to B). |
> > > |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. |
> > |
They will be reading different times, but you still can't assume either of them was "running slow." As Paparios says, it's a geometric projection effect. |
> |
Why can not I say that one clock is running slower as the other (while moving)? |
Because you cannot ascertain WHICH clock is "moving." Speed is purely relative.
> | Such an description is in accordance with the final observation i.e. that the readings are different. |
But it's not in accordance with what actually happens. Remember? Which clock ends up behind the other depends upon who changed frames.
> |
IMO the only lesson learned from this experiment that when you want to
understand the laws of nature you should not use clocks which move relative
to each other and if you do then you should adjust the readings of each
clock.
Nicolaas Vroom |
Sounds like you are reinventing the first postulate (PoR) here.
> | On 6/27/17 6/27/17 7:52 AM, Nicolaas Vroom wrote: |
> > | Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
> |
OK. That is some incredibly powerful "tool", far beyond what is possible today. But gedankens can invoke such "tools". I assume both clocks are ideal and undamaged. |
Anyway I assume that you agree with the possible outcome of such an experiment. A better word for tool is maybe actor.
> > | That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
> |
No. The problem is as much in your wording as in your physics, but BOTH are wrong. Wording: When you say "that clock runs slow", you mention ONLY the clock, and thus cannot impose some OTHER reference, all you can use is the clock ITSELF. |
I write on purpose that clock B runs slower than clock A. That means I compare the condition of two clocks based on its final outcome.
> | And the clock just ticks along at its usual rate. |
> | Indeed put a frequency standard right next to it, co-moving with it, and it will show that the clock DOES tick at its usual rate. So moving clocks DO NOT RUN SLOW. |
When you put an other frequency standard A' near clock A and one B' near B (co moving with B) the pairs A',A and B',B each pair will show the same result but disagree which each other: the pair B',B will run behind.
> | This was not fully understood until after 1916 when GR was published. Even today, elementary or popular writings often take that shortcut to avoid the lengthy and complicated explanation I give here. |
I do not understand what GR has to do with this.
> | One can say "Measured in the inertial frame of clock A, clock B did tick more slowly than clock A". But you didn't say that. Remember there is no "absolute" frame, and if you make a measurement in some frame, you MUST mention the frame used. It seems you are implicitly assuming a measurement in the frame of clock A, but you did NOT mention that. |
The frame I use is a table which initialy and finaly contains two clocks: A and B.
> | Physics: Your scenario does NOT display "time dilation", it demonstrates a different geometrical phenomenon: different timelike paths through spacetime can have different elapsed proper times. Every clock ALWAYS ticks at its usual rate, regardless of where it might be located or how it might be moved [#]. If you want to compare a moving or distant clock to a clock nearby, you must use SIGNALS from the other clock to this one, and you must consider how those SIGNALS are affected (by the motion or distance) -- do that and you find the ENTIRE effect is due to the way those SIGNALS are measured, leaving "no room" for the clocks to tick at different rates. |
IMO the physical explanation that at the end of the experiment the two clocks show a different reading is only because the two clocks experience different accelerations. These different accelerations influence the internal operation of each clock differently. IMO when you move a clock which operation is based on light signals which the speed of light (a little less) it does (almost) not tick at all. (comparing equal distances)
> | There are other, more direct experimental implementations of the "twin paradox".... |
I do not understand why you call this a paradox. If my clock A shows 10 ticks and the moving clock B shows 6 ticks when the moving clock returns you know there is a time keeping problem. When the moving clock B shows 3 ticks at furthest distance and this distance is known (in straight line and B's speed is constant) then IMO it only makes sense to use my 10 ticks in order to calculate B's average speed. (because the clock B is running slow)
Nicolaas Vroom.
> | On Monday, 26 June 2017 05:19:57 UTC+2, Gary Harnagel wrote: |
> > | On Sunday, June 25, 2017 at 8:45:59 PM UTC-6, Robert Winn wrote: |
> > > |
On Sunday, June 25, 2017 at 6:00:20 PM UTC-7, Gary Harnagel wrote: |
> > > > |
> > > > > |
only accurate clocks and inaccurate clocks. So how do you think Einstein came to have a slower clock? |
> > > > |
He probably bought it at Walgreens, like YOU did. |
> > > |
No, I think you are wrong about that. |
> > |
You are the one in error, mon ami. And Einstein was wrong about moving clocks running slow. Didn't you get the memos? They've been floating around here for quite some time. |
> |
Somewhere along the line I'am missing something. Can some one give me a link to the memos mentioned? |
> > > |
Einstein definitely said he had a slower clock. |
> > |
No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
> |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. That means during the time that clock B travelled (away and back) clock B did run slower than clock A. To describe this phemomena (experiment) IMO the wording APPEAR is wrong. Nicolaas Vroom |
The equations that describe what you describe are the equations that scientists threw away in 1887, the Galilean transformation equations.
> | On Tuesday, June 27, 2017 at 8:33:11 AM UTC-6, Nicolaas Vroom wrote: |
> > |
On Tuesday, 27 June 2017 15:50:13 UTC+2, Gary Harnagel wrote: |
> > > |
On Tuesday, June 27, 2017 at 6:52:06 AM UTC-6, Nicolaas Vroom wrote: |
> > > > |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
> > > |
Yes, it is running at the same rate as A, but it is behind. |
> > > > |
That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
> > > |
But you have no way of directly determining that. |
> > |
That is correct if you mean during the time the two clocks were not at my desk. After clock B returned and before looking there are three possible answers: 1) They both show the same time. 2) Clock B shows an earlier time and runs behind. 3) Clock A shows an earlier time and runs behind. In case 2) clock B is considered the moving clock In case 3) clock A is considered the moving clock |
> |
A and B cannot get back together again unless one of them changes frames. The one that changes frames will lag the other. |
> > > |
You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
> > |
I do not see any paradox. This is a physical experiment and it requires a physical explanation. |
> |
And there is one: one that does not require either clock to actually be running slower. |
> > |
While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system. |
> |
Sure. Not really so difficult after all. Of course, Doppler effects and time delays would have to be taken into account. |
> > > > |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> > > |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> > |
That is "correct" before they meet again. |
> |
Which can't happen unless one of them changes frames. |
So go ahead and explain what you mean by this changing of frames. As far as I can tell, a clock in S' never leaves S'.
> |
> > > |
(which is why A's clock APPEARS to run slower to B). |
> > |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. Nicolaas Vroom. |
> |
They will be reading different times, but you still can't assume either of them was "running slow." As Paparios says, it's a geometric projection effect. |
Geometric projection effect. That sounds kind of complicated. Could we say that one frame of reference just has fewer transitions of a cesium atom?
> | On 6/27/17 6/27/17 7:52 AM, Nicolaas Vroom wrote: |
> > | On Monday, 26 June 2017 05:19:57 UTC+2, Gary Harnagel wrote: |
> >> | No, he didn't say that. He said moving clocks run slow, and he was wrong about that. What he SHOULD have said is that moving clocks APPEAR to run slow. |
> |
Yes. |
> > |
Consider two identical clocks A and B in front of me, on a table. They are identical in the sense that after one year the two clocks still show the same time/reading. Using a "tool" clock B is moved away and when clock B is brought back, from now on: when clock A shows 12 o'clock clock B shows 11.55. That means there is a constant time difference between the two clocks. Clock B runs behind. |
> |
OK. That is some incredibly powerful "tool", far beyond what is possible today. But gedankens can invoke such "tools". I assume both clocks are ideal and undamaged. |
> > |
That means during the time that clock B travelled (away and back) clock B did run slower than clock A. |
> |
No. The problem is as much in your wording as in your physics, but BOTH are wrong. Wording: When you say "that clock runs slow", you mention ONLY the clock, and thus cannot impose some OTHER reference, all you can use is the clock ITSELF. And the clock just ticks along at its usual rate. Indeed put a frequency standard right next to it, co-moving with it, and it will show that the clock DOES tick at its usual rate. So moving clocks DO NOT RUN SLOW. This was not fully understood until after 1916 when GR was published. Even today, elementary or popular writings often take that shortcut to avoid the lengthy and complicated explanation I give here. One can say "Measured in the inertial frame of clock A, clock B did tick more slowly than clock A". But you didn't say that. Remember there is no "absolute" frame, and if you make a measurement in some frame, you MUST mention the frame used. It seems you are implicitly assuming a measurement in the frame of clock A, but you did NOT mention that. Physics: Your scenario does NOT display "time dilation", it demonstrates a different geometrical phenomenon: different timelike paths through spacetime can have different elapsed proper times. Every clock ALWAYS ticks at its usual rate, regardless of where it might be located or how it might be moved [#]. If you want to compare a moving or distant clock to a clock nearby, you must use SIGNALS from the other clock to this one, and you must consider how those SIGNALS are affected (by the motion or distance) -- do that and you find the ENTIRE effect is due to the way those SIGNALS are measured, leaving "no room" for the clocks to tick at different rates. [#] That is \integral d\tau, when integrated along the path of the clock between successive ticks, ALWAYS remains the same, regardless of the path or the geometry of the manifold along the path. Here \tau is the clock's proper time. The fact that clocks A and B experience different elapsed proper times along their different paths through spacetime is no more remarkable than the fact that for triangle UVW the paths UV and UWV have different lengths. Indeed if your "tool" used instantaneous accelerations and inertial motion between them, your scenario is just a triangle in spacetime, with clock a traveling UV and clock B traveling UWV (U is when they separate, V is when they rejoin, and W is a turn-aound in clock B's path that enables it to come back to clock A). |
> > |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> |
Yes. Say "is measured (in the appropriate inertial frame)" instead. This is not mere appearance, and this effect can and does have real physical consequences (e.g. pion beam lines that are a kilometer long -- in the lab it takes the pions 3.3 microseconds to traverse the beamline, but the pions experience elapsed proper times considerably less than their 26 nanosecond lifetime). There are other, more direct experimental implementations of the "twin paradox".... Tom Roberts |
Well, that all sounds very technical, but if you are going to define a second as a certain number of transitions of a cesium atom, then you still come up with the fact that one cesium atom has slower transitions than another cesium atom. I think Galileo had a better definition of a second than scientists of today have.
> | On Tuesday, 27 June 2017 17:32:03 UTC+2, Gary Harnagel wrote: |
> > | On Tuesday, June 27, 2017 at 8:33:11 AM UTC-6, Nicolaas Vroom wrote: |
> > > |
After clock B returned and before looking there are three possible answers: 1) They both show the same time. 2) Clock B shows an earlier time and runs behind. 3) Clock A shows an earlier time and runs behind. In case 2) clock B is considered the moving clock In case 3) clock A is considered the moving clock |
> > |
A and B cannot get back together again unless one of them changes frames. The one that changes frames will lag the other. |
> |
Cannot they both change frames? Does not any change in speed implies a change in frame? Anyway what has changing frames to do with this experiment? IMO the most important issue is (in case 2) that clock B must change its speed (direction of speed) |
> > > > |
You ASSUME that it was running slower in transit, but there is another explanation, one that doesn't run into a paradox (i.e., while B was in transit, he saw A's clock running slower). |
> > > |
I do not see any paradox. This is a physical experiment and it requires a physical explanation. |
> > |
And there is one: one that does not require either clock to actually be running slower. |
> |
I do not understand how this explanation explains the outcome of the experiment i.e. that when the two clocks meet their readings are different. |
> > > |
While B is in transit it is "difficult" to see A's clock The same for A to see B's clock. Ofcourse each can transmit at regular intervals a timing system. |
> > |
Sure. Not really so difficult after all. Of course, Doppler effects and time delays would have to be taken into account. |
> > > > > |
To describe this phemomena (experiment) IMO the wording APPEAR is wrong. |
> > > > |
Nope. What is wrong is claiming that clocks in motion actually run slower. The first problem is, What do you mean by "in motion"? B can justifiably claim that HE is stationary and A is in motion |
> > > |
That is "correct" before they meet again. |
> > |
Which can't happen unless one of them changes frames. |
> |
If you mean unless at least one changes its speed. In this experiment clock B has at least change its speed twice. |
> > > > |
(which is why A's clock APPEARS to run slower to B). |
> > > |
And vice versa. The wording APPEARS is tricky when they are in transit. IMO after they meet the word APPEAR can not be used any more. |
> > |
They will be reading different times, but you still can't assume either of them was "running slow." As Paparios says, it's a geometric projection effect. |
> |
Why can not I say that one clock is running slower as the other (while moving)? Such an description is in accordance with the final observation i.e. that the readings are different. IMO the only lesson learned from this experiment that when you want to understand the laws of nature you should not use clocks which move relatif to each other and if you do then you should adjust the readings of each clock. Nicolaas Vroom |
The definition of a frame of reference appears to me to need to be clarified. Einstein appeared to understand it better. He said there was a frame of reference of a stationary clock called S and a frame of reference of a moving clock called S'. If the moving clock slows down and stops moving relative to S, it still has its own frame of reference S'. The only thing we can say with regard to S and S' is that neither is moving relative to the other. There is no change of frames of reference.
> |
The equations that describe what you describe are the equations that scientists threw away in 1887, the Galilean transformation equations.
x'=x-vt y'=y z'=z t'=t |
Scientists did not "throw them away", it's just that we now recognize they are only an approximation to a MUCH better theory that uses Lorentz transforms between (locally) inertial frames.
And that recognition did not happen in 1887, more like the decade or two after 1905 -- it was a process, not a single event; it started with Einstein's 1905 paper. Note the key point of that paper is not his postulates, it is his approach: recognizing the importance of symmetries in physics.
Tom Roberts
> | On Wednesday, 28 June 2017 05:27:28 UTC+2, tjrob137 wrote: |
>> | Wording: When you say "that clock runs slow", you mention ONLY the clock, and thus cannot impose some OTHER reference, all you can use is the clock ITSELF. |
> |
I write on purpose that clock B runs slower than clock A. |
But that is NOT what happens. Clock B just travels a different path between the endpoints than clock A, and the paths have different elapsed proper times.
Two cars drive from Chicago to New York, one directly and one via New Orleans. Their odometers display different distances. Do you seriously think the calibrations of their odometers are different? -- Of course not, they merely traveled different distances between the endpoints. The twin scenario, and yours, are EXACTLY the same, except in a space-time plane. It's also true that for the cars we have a clear an obvious "frame" to use, that of the earth; for the clock scenarios there is no such ready-made and obvious frame of reference.
Comparing the two clocks' values at the endpoints is NOT sufficient to conclude their tick rates are different. You MUST also account for their different paths, and when you do, you find it accounts for 100% of the difference, leaving "no room" for them to tick at different rates.
After all, this has been done, several times in several ways.
> | That means I compare the condition of two clocks based on its final outcome. |
OK. But the ONLY conclusions you can make from that are those supported by the measurements you made. You did NOT measure their tick rates, and thus cannot make any statements about their tick rates.
>> | And the clock just ticks along at its usual rate. |
> | No. Based on the final observations at least one does not. |
Not true. See above.
You did NOT compare rates, and thus cannot make any statement about their rates.
I, on the other hand, can extend your scenario to include frequency standards co-located and co-moving with each clock. They MEASURE each clock to always tick at its usual rate.
>> | This was not fully understood until after 1916 when GR was published. Even today, elementary or popular writings often take that shortcut to avoid the lengthy and complicated explanation I give here. |
> |
I do not understand what GR has to do with this. |
It taught physicists that the integral of proper time is the relevant quantity.
>> | Physics: Your scenario does NOT display "time dilation", it demonstrates a different geometrical phenomenon: different timelike paths through spacetime can have different elapsed proper times. Every clock ALWAYS ticks at its usual rate, regardless of where it might be located or how it might be moved [#]. If you want to compare a moving or distant clock to a clock nearby, you must use SIGNALS from the other clock to this one, and you must consider how those SIGNALS are affected (by the motion or distance) -- do that and you find the ENTIRE effect is due to the way those SIGNALS are measured, leaving "no room" for the clocks to tick at different rates. |
> |
IMO the physical explanation that at the end of the experiment the two clocks show a different reading is only because the two clocks experience different accelerations. These different accelerations influence the internal operation of each clock differently. |
Not in SR or GR. In both of them, it is the different PATH that matters, not the different accelerations. Of course in SR one needs accelerations to make the paths different. But in GR one does not. For all cases, it is the PATH LENGTH (integral of proper time) that matters.
>> | There are other, more direct experimental implementations of the "twin paradox".... |
> |
I do not understand why you call this a paradox. |
Because that is its name.
"Paradox" has two meanings, and the relevant one is "a SEEMING contradiction that upon analysis proves to be fully consistent".
> | If my clock A shows 10 ticks and the moving clock B shows 6 ticks when the moving clock returns you know there is a time keeping problem. |
Not "problem", but "difference". After all, this is completely unavoidable: different paths can have different lengths, and for a timelike path that length is elapsed proper time.
Tom Roberts
>> | Tom Roberts |
> |
So, in other words, you are saying that if you step on the accelerator of your car, your car gets shorter. Here is the problem you have. If you use the correct equations for relativity, they show that if one clock ticks ten times and the other only ticks six, then according to the time of the slower clock, the car is not getting shorter, it is going faster. The equations show the exact relationship. |
Totally nonsense. It reveals you have no idea what is going on in Physics.
> | Since you say that the Galilean transformation equations are total nonsense, go ahead and show the proof of what you say. |
The problem with the Galilean transformations is not that they are total nonsense. They are a perfectly legitimate set of coordinate transformations. However, they do not exactly describe the relationship between relatively moving systems of inertial coordinates (meaning coordinate systems in which Newton's equations of mechanics hold good to the first approximation).
Remember, Maxwell's equations (1865) already showed that objects (whose size and shape is governed by electromagnetic forces) contract by a factor of sqrt(1 - (v/c)^2) when moving with speed v, and this has been confirmed experimentally. Any viable theory of relativity must account for this.
> |
Well, I have to go by what Einstein said, |
No, you DON'T "have" to go by what Saint Albert said. It's just that you WANT to do that because your mind is hermetically sealed and refuses to accept new data.
> | not by what one of his disciples says a hundred and some years later. |
Why not? If an aged idea is more valuable than a new one, why not accept phlogiston or the existence of only four elements (earth, air, fire and water)?
> | Einstein said that the clock in S' was slower. |
Yes, he did. He was wrong. That means YOU are wrong, too. He had an excuse because he lived a century ago. YOU don't have that excuse.
> | That is what the equation indicates. |
Is it? What qualifies you to assert that? The LT relates time on clocks that are not co-located. If they aren't co-located, how do you know your measurement is accurate? The fact is that you don't. Furthermore, the LT predicts that the clock in S' will measure the clock in S as the slower clock, so your assertion that the clock in S' is actually running slower is completely irrational.
> | To get a faster clock you have to use General Relativity. |
Trying to insert GR into an argument about SR is pettifogging.
> | Nothing refutes the Galilean transformation equations. |
Completely false and baseless assertion.
> | [Regurgitated falsehoods deleted] |
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