
#145
Feb2512, 06:29 AM

P: 344

Time, and hence 1 second is not comparable the same in different space time,  do you not agree to that? 



#146
Feb2512, 06:36 AM

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P: 16,470





#147
Feb2512, 08:01 AM

P: 344

Clocks ticks different in different space time. Let us say you were living in a relative very strong gravitionel field, compared to me. Let’s say it will take 2 second on my atomic clock,  to observer one second ticking on yours atomic clock. Opposite it will take you ½ second to observe 1 second ticking on my atomic clock. The definition of 1 second is for both of us 9,192,631,770 cesium frequency cycles per second. But it will take a comparable long second (relative double period “of time”) for your clock to reach this number, and only a relative comparable short (½) period, and hence a short second for me to count the same numbers of frequencies. So the comparable second is not the same. I cannot understand how you seem not to agree to that. 



#148
Feb2512, 08:14 AM

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P: 16,470

Please answer the question. How are you comparing clock rates at different points in spacetime? 



#149
Feb2512, 11:17 AM

P: 344

I cannot see any other option,  can you ? 



#150
Feb2512, 11:40 AM

PF Gold
P: 4,081

Bjarne, your answers are getting more and more feeble. I think you misunderstand what is meant by "the laws of physics are the same in all inertial frames" so I'll spell it out.
If an experiment is done in lab A to test the law f=ma using billiard ball type experiments and of course measuring with local clocks and rulers, then the result will be the same as in any other lab frame, where of course, they use their local clocks and rulers. It matters not a jot if the local clocks and rulers are 'different', both frames will verify that f=ma is true, up to a small experimental error. Going on about seconds or centimeters being different in different frames is irrelevant. 



#151
Feb2512, 01:58 PM

Mentor
P: 16,470

A) Broadcast a reference signal, measure the frequency of the signal locally at each clock B) Take a reference clock, physically transport it from one clock to the other and measure the rate of the reference locally at each clock C) Agree on a standard physics experiment as a reference, perform it locally at each clock and measure the time for the experiment D) Agree on an astronomical reference, and measure the time for the astronomical reference locally Your suggested measurement of one year with two clocks is an example of D. Your mention of satellites probably refers to A. Mentz114's recent post refers to C, which encapsulates the principle of relativity. I came up with B on my own. With D and A you will get that the Earth clock and the ISS clock run at different rates. With B and C you will get that the Earth clock and the ISS clock run at the same rates. The beauty of GR is that it is a single law of physics which explains A, B, C, and D all together. 



#152
Feb2612, 01:32 AM

P: 344

Double .




#153
Feb2612, 01:32 AM

P: 344

I was confused because I thought you did not agree to that,  when times ticks different, in different spacetime, then each second also does,  whereby the comparable length off 1 second must be either stretching or shrinking. – So I expected a different kind of answer to your question, not easy to know what that possible could be. 



#154
Feb2612, 06:12 AM

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P: 16,470





#155
Feb2612, 09:13 AM

PF Gold
P: 4,081

Bjarne, I find your post #154 difficult to follow. It is not logically argued and poses more questions than it gives answers.
Have you seen this ? http://wwwistp.gsfc.nasa.gov/stargaze/Smass.htm It is about experiments carried out on a space station. There is a universe of evidence that the laws of nature are the same everywhere. We know that atoms continue to emit and absorb the same pattern of spectral lines which have been recognised in millions of astronomical bodies. On a large scale, the GR cosmological models explain most of what we can measure about the universe. What you are proposing is 'new' physics. If the laws of nature really are laws of nature, they must apply everywhere. If there is experimental evidence to support it, then they must be modified, like relativity altered Newtonian concepts. Your position is impossible to argue unless you can produce this experimental evidence. 



#156
Feb2612, 10:48 AM

P: 344

Either time is ticking different, or it is not. According to relativity time is ticking different. Many experiments and experiences confirm this. So I still cannot see any point with the question. 



#157
Feb2612, 11:09 AM

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P: 16,470





#158
Feb2612, 11:45 AM

P: 344





#159
Feb2612, 11:54 AM

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P: 16,470

I mean to take the reference clock, place it locally next to the test clock (either the Earth clock or the ISS clock), and measure the duration of one "tick" of the reference clock using the local test clock.




#160
Feb2612, 12:52 PM

P: 344

A + D is comparable measurement I agree to all that, but it has not much with the question to do. I do off course mean A+D Do we know (for sure) whether distances are comparable different too, so as time and speed is (see A+D),  in different spacetime. I have read that massenergy conservation will changes the Bohr radius, which also must apply to relativity? 



#161
Feb2612, 07:18 PM

Mentor
P: 16,470

Please, let's not waste another dozen or more posts chasing this down. Just describe your experimental method of comparing two spatially separated distances as clearly and succinctly as possible. 



#162
Feb2712, 02:19 AM

P: 344

It confused me you could misunderstand that so much. I believe it is impossible. Maybe only mathematical possible. Already we compare space with a stretching rubber band,  or use the expression "curvature" What does that mean? Can we get closer to an understandable nature of that? What happens with the ruler in such “bended” space? ( what do we know or not know) At least seen from a mathematical perspective, is space stretching like the rubber band? 


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