If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. 


Thread Tools  Display Modes 
#1




Time Dilation on the International Space Station
https://en.wikipedia.org/wiki/File:D..._dilation.pngT
Why don't you measure time dilation on the ISS ? Physicists are claiming that clocks on the ISS would lose 24.6 us/day, whereas clocks on the GPS are claimed to gain 37 us/day. Since the clocks are in free fall in both cases this seems highly unlikely to me. However the physicists claim that,due to the higher velocity and lower altitude of the ISS, the direction of the time dilation would reverse. If it is really true this would indeed be a spectacular demonstration of the correctness of Einstein's Special and General Relativity, but I don't believe it myself. 
Ads 
#2




Time Dilation on the International Space Station
On 14/05/2018 02:53, Keith Stein wrote:
https://en.wikipedia.org/wiki/File:D...e_dilation.png Sorry i messed up the link  That should work now. Why don't you measure time dilation on the ISS ? Physicists are claiming that clocks on the ISS would lose 24.6 us/day, whereas clocks on the GPS are claimed to gain 37 us/day. Since the clocks are in free fall in both cases this seems highly unlikely to me. However the physicists claim that,due to the higher velocity and lower altitude of the ISS, the direction of the time dilation would reverse. If it is really true this would indeed be a spectacular demonstration of the correctness of Einstein's Special and General Relativity, but I don't believe it myself. 
#3




Time Dilation on the International Space Station
In article ,
says... https://en.wikipedia.org/wiki/File:D..._dilation.pngT Why don't you measure time dilation on the ISS ? Physicists are claiming that clocks on the ISS would lose 24.6 us/day, whereas clocks on the GPS are claimed to gain 37 us/day. Since the clocks are in free fall in both cases this seems highly unlikely to me. Time dilation happens due to the difference in velocity between two points. It absolutely happens. GPS takes that into account due to the precise timings required (i.e. since it's used on earth, the time reference is adjusted such that receivers on the earth get the correct time). I'm not sure how ISS sets its clocks, but the computers are all networked together, so no doubt they're using the same time reference. In practice this isn't really a big deal since the difference in velocity isn't that great. However the physicists claim that,due to the higher velocity and lower altitude of the ISS, the direction of the time dilation would reverse. If it is really true this would indeed be a spectacular demonstration of the correctness of Einstein's Special and General Relativity, but I don't believe it myself. It's complex stuff. You have to take into account both general relativity and special relativity. https://en.wikipedia.org/wiki/Time_dilation Jeff  All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. 
#4




Time Dilation on the International Space Station
On 14/05/2018 11:16, Jeff Findley wrote:
In article , says... https://en.wikipedia.org/wiki/File:D..._dilation.pngT Why don't you measure time dilation on the ISS ? Physicists are claiming that clocks on the ISS would lose 24.6 us/day, whereas clocks on the GPS are claimed to gain 37 us/day. Since the clocks are in free fall in both cases this seems highly unlikely to me. Time dilation happens due to the difference in velocity between two points. It absolutely happens. GPS takes that into account due to the precise timings required (i.e. since it's used on earth, the time reference is adjusted such that receivers on the earth get the correct time). I'm not sure how ISS sets its clocks, but the computers are all networked together, so no doubt they're using the same time reference. In practice this isn't really a big deal since the difference in velocity isn't that great. However the physicists claim that,due to the higher velocity and lower altitude of the ISS, the direction of the time dilation would reverse. If it is really true this would indeed be a spectacular demonstration of the correctness of Einstein's Special and General Relativity, but I don't believe it myself. It's complex stuff. You have to take into account both general relativity and special relativity. https://en.wikipedia.org/wiki/Time_dilation Thank you Jeff. The link i gave at the beginning of this post comes from that same Wikipedia article. The graph i linked to shows clearly that they are claiming that clocks on the GPS GAIN 37 us/day, while clocks on the ISS would LOSE 24.6 us/day. I can tell you are convinced, even without any test on the ISS, but it seems highly improbable to me. A big advantage of doing the test on the ISS would be that the clocks could be compared while alongside each other, which would be far more certain and accurate than comparing clocks which are 20,000 km apart, and moving rapidly relative to each other, as is the case with GPS. Simple way to do the test on the ISS: 1. Synchronize two clocks. 2. Take one to the ISS. 3. Next flight up take up the other. 4. Compare the two clocks on the ISS. keith stein Jeff 
#5




Time Dilation on the International Space Station
In article ,
says... On 14/05/2018 11:16, Jeff Findley wrote: In article , says... https://en.wikipedia.org/wiki/File:D..._dilation.pngT Why don't you measure time dilation on the ISS ? Physicists are claiming that clocks on the ISS would lose 24.6 us/day, whereas clocks on the GPS are claimed to gain 37 us/day. Since the clocks are in free fall in both cases this seems highly unlikely to me. Time dilation happens due to the difference in velocity between two points. It absolutely happens. GPS takes that into account due to the precise timings required (i.e. since it's used on earth, the time reference is adjusted such that receivers on the earth get the correct time). I'm not sure how ISS sets its clocks, but the computers are all networked together, so no doubt they're using the same time reference. In practice this isn't really a big deal since the difference in velocity isn't that great. However the physicists claim that,due to the higher velocity and lower altitude of the ISS, the direction of the time dilation would reverse. If it is really true this would indeed be a spectacular demonstration of the correctness of Einstein's Special and General Relativity, but I don't believe it myself. It's complex stuff. You have to take into account both general relativity and special relativity. https://en.wikipedia.org/wiki/Time_dilation Thank you Jeff. The link i gave at the beginning of this post comes from that same Wikipedia article. The graph i linked to shows clearly that they are claiming that clocks on the GPS GAIN 37 us/day, while clocks on the ISS would LOSE 24.6 us/day. I can tell you are convinced, even without any test on the ISS, but it seems highly improbable to me. You mean something like this: NASA  Atomic Clock Ensemble in Space https://www.nasa.gov/mission_pages/s...ments/2076.htm l Atomic Clock Ensemble in Space (ACES) data analysis https://arxiv.org/abs/1709.06491 So the very thing you propose is planned. It doesn't look like it's flown to ISS yet though. At any rate, relativity has been proven many times before. https://en.wikipedia.org/wiki/Hafele...ing_experiment A big advantage of doing the test on the ISS would be that the clocks could be compared while alongside each other, which would be far more certain and accurate than comparing clocks which are 20,000 km apart, and moving rapidly relative to each other, as is the case with GPS. Simple way to do the test on the ISS: 1. Synchronize two clocks. 2. Take one to the ISS. 3. Next flight up take up the other. 4. Compare the two clocks on the ISS. Much simpler tests have already proven relativity. The equations hold true. There is no need to think the concept is improbable. Jeff  All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. 
Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Space Shuttle and International Space Station News for Tuesday 18 November 2014  NASA via sci.space.tech Admin  Space Station  0  November 20th 14 03:43 AM 
Space Shuttle and International Space Station News for Tuesday 21 October 2014  NASA via sci.space.tech Admin  Technology  0  October 21st 14 11:39 PM 
Time Contraction Versus Time Dilation Quick Answer  [email protected]fni.com  Misc  7  July 16th 10 12:39 PM 
will our space shuttle discovery and our international space station be safe from the space trash that the US and other counries earlier left up there?  Jonathan  History  1  September 6th 09 12:51 AM 
Time dilation and expanding space  Robert Karl Stonjek  Astronomy Misc  37  March 9th 07 02:50 PM 