Author Topic: DIY measurement of time dilation in a gravity well  (Read 4980 times)

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Online CirclotronTopic starter

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DIY measurement of time dilation in a gravity well
« on: January 21, 2023, 10:45:49 pm »
Disclaimer - I only have a YouTube level of understanding of the following subject.  :P

It is widely accepted the time proceeds proportionally more slowly when gravity is present. For example, when a perfect clock 1km above earth’s surface shows exactly one day of elapsed time, an identical perfect clock on the surface of the earth will show about 10nS less duration for the same day. A practical example of this real phenomena is the need to keep GPS satellite clocks in zero G synced with ground based clocks.

How can we check out this weird situation at home? If we reduce the aforementioned 1km distance to 100 metres and we put an oscillator of 100MHz on top of a 100 metre tower and an identical oscillator on the ground and feed both into our dual trace scope, after one day we should see 36 degrees of phase shift between the two oscillators.

Not everyone has two oscillators with the required degree of stability, least of all me. What then if we have a single oscillator on the ground and a feed coax up the 100 metre tower and a transmitting antenna aiming back down toward us. Then feed to the scope both a signal directly from the oscillator and one received from the elevated antenna. There will be propagation delay of course, but both signals will initially have a certain fixed phase difference.

If in fact time proceeds more slowly at ground level compared to 100 metres above the ground then we should perhaps see the two 100MHz signals gradually creeping out of phase at 36 degrees per day despite coming from the same oscillator source, should we not?
« Last Edit: January 22, 2023, 12:06:09 pm by Circlotron »
 

Offline dietert1

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Re: DIY measurement of time dilation in a gravity well
« Reply #1 on: January 21, 2023, 11:15:47 pm »
I'd guess that your setup won't produce any phase travel. But general relativity is a difficult subject and most of the time requires serious mathematical efforts. I'd recommend reading about gravitational red shift and whether it reverses when going back.

Regards, Dieter

PS: There is a nice Wikipedia description of such terrestrial experiments. They use two clocks to generate and measure the phase travel.
« Last Edit: January 21, 2023, 11:28:35 pm by dietert1 »
 

Online CirclotronTopic starter

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Re: DIY measurement of time dilation in a gravity well
« Reply #2 on: January 21, 2023, 11:37:00 pm »
I'd guess that your setup won't produce any phase travel. But general relativity is a difficult subject and most of the time requires serious mathematical efforts. I'd recommend reading about gravitational red shift and whether it reverses when going back.
Yes, I did actually read about gravitational red shift and that is what got me thinking about how an ordinary person could conduct a somewhat comparable experiment. The fact that we can see a star is red shifted makes me think the experiment might work. I’ll have a further read up on the subject though.
 

Offline WatchfulEye

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Re: DIY measurement of time dilation in a gravity well
« Reply #3 on: January 22, 2023, 10:54:41 am »
The experiment you propose is feasible, and indeed has been done in the famous Hafele–Keating experiment. The HK experiment was complicated by the fact that the clocks were travelling in commercial airliners, and so the experiment measured both the effect of gravitational red shift and special relativistic time dilation, with the latter being the dominant effect.

The problem is that the gravitational effect is small, and few oscillators have the required stability. Measuring 3.6 ns of phase shift over 24 hours is a fractional deviation of 4.2 x 10^-14 - few oscillators have that level of stability. You're looking at something like the high performance variant of the microchip 5071A, which is specified to have an Allan deviation at 10^5 seconds (approx 1 day) of <2.7 x 10^-14. The Allan deviation can be thought of as the standard deviation of the time measurement for a specified period. So, while this oscillator is exceptional, the oscillator noise is a substantial fraction of the signal - so you would need to repeat the experiment multiple times, or run for a longer period, to collect sufficient statistics.

If you could increase the height to 1 km or more, for example by climbing a mountain (or visiting a ski resort), then your signal becomes much larger and it becomes feasible to measure it more easily. The difficulty is measuring the phase shift over this sort of distance - options include GPS transfer (each oscillator logs phase shift relative to GPS satellite(s),  or you simply transport the test oscillators to the test location, and set the experimental duration long enough that the effects of travel are minimal.

With a high enough location, then the experiment is accessible to the (motivated) amateur:
http://leapsecond.com/great2005/

 
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Online CirclotronTopic starter

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Re: DIY measurement of time dilation in a gravity well
« Reply #4 on: January 22, 2023, 12:00:48 pm »
(each oscillator logs phase shift relative to GPS satellite(s),  or you simply transport the test oscillators to the test location,
I was suggesting using a single oscillator and splitting the signal into two paths. That way any drift in the single oscillator would affect both measured signals and mostly null out. That way any normal and reasonably stable oscillator could be used. And any creep in phase difference due to difference in rate of elapsed time should hopefully keep on accumulating until it is clearly above any noise.
 

Offline WatchfulEye

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Re: DIY measurement of time dilation in a gravity well
« Reply #5 on: January 22, 2023, 12:51:44 pm »
The signal when sent up your coax to your elevated transmit antenna will be redshifted, but when it returns to earth where your apparatus is, it will be blueshifted an equivalent amount - so this experiment will not be able to measure it.
 
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Online BrianHG

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Re: DIY measurement of time dilation in a gravity well
« Reply #6 on: January 22, 2023, 04:08:09 pm »
This guy landed some test equipment you can use to make the measurement:
https://www.eevblog.com/forum/chat/how-an-atomic-clock-really-works-zeeman-alignment/msg4494280/#msg4494280
(Though I doubt he would let you borrow them...)

Run network or coax cable between the 2 clocks and change the altitude of one.
On an XY scope, compare the time of drift between the two 5MHz outputs, once when their heights matched, then again when one is 100m above the other.
 

Online SiliconWizard

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Re: DIY measurement of time dilation in a gravity well
« Reply #7 on: January 22, 2023, 08:19:15 pm »
Tricky though.

It's even trickier than assessing the Earth's curvature at 100m above ground. ::)
 

Offline David Hess

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Re: DIY measurement of time dilation in a gravity well
« Reply #8 on: January 23, 2023, 02:29:14 pm »
Sending the signal up the tower and back will not work for the reason WatchfulEye identifies.  If it did, then there would be an increasing phase shift with time.  This would be a duplication of the Michelson–Morley experiment.

If there was some way to "chop" the two oscillators, then their drift could be cancelled out, and a lower noise measurement made, but that would involve swapping them at a high rate somehow.  Mount them on a big Ferris wheel, or pair of linked elevators?
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #9 on: January 25, 2023, 11:27:17 am »
Disclaimer - I only have a YouTube level of understanding of the following subject.  :P

It is widely accepted the time proceeds proportionally more slowly when gravity is present. For example, when a perfect clock 1km above earth’s surface shows exactly one day of elapsed time, an identical perfect clock on the surface of the earth will show about 10nS less duration for the same day. A practical example of this real phenomena is the need to keep GPS satellite clocks in zero G synced with ground based clocks.

How can we check out this weird situation at home? If we reduce the aforementioned 1km distance to 100 metres and we put an oscillator of 100MHz on top of a 100 metre tower and an identical oscillator on the ground and feed both into our dual trace scope, after one day we should see 36 degrees of phase shift between the two oscillators.

Not everyone has two oscillators with the required degree of stability, least of all me. What then if we have a single oscillator on the ground and a feed coax up the 100 metre tower and a transmitting antenna aiming back down toward us. Then feed to the scope both a signal directly from the oscillator and one received from the elevated antenna. There will be propagation delay of course, but both signals will initially have a certain fixed phase difference.

If in fact time proceeds more slowly at ground level compared to 100 metres above the ground then we should perhaps see the two 100MHz signals gradually creeping out of phase at 36 degrees per day despite coming from the same oscillator source, should we not?
Boy o boy – where do i start!
Firstly, without meaning to offend, u know almost zilch about this stuff, & the little that u do know is wrong. Me myself i know a bit more than u, hence i am happy to discuss this stuff.
1. There is no such thing as time. However, everything that we see & feel is a process, & all processes have a rate of ticking, & that ticking is affected by lots of things.
2. Irrelevant but i will comment anyhow. GPS duz not in any way need the synchronization of any clocks anywhere.
3. U mention a perfect clock on the surface & 1km up. Here u show that u don’t understand (1). If there were such a thing as time, & if Einstein were correct, then u would be ok to use the words that u used. But there is no such thing as time, & Einstein was not correct. Getting to the point, what i mean is that u said "clock", meaning any & all clocks. No. Different clocks will be affected by elevation in different ways. And, having identical clocks duznt get around this problem.
4. U mentioned that problem of stability. That is fair enuff. But i would like to point out that much of the instability of clocks is due to an ignorance of real physics. Much of the instability is due to certain effects, which if understood can be accounted for, if not avoided.
5. Re having a single oscillator & a 100 m antenna. I don’t see how u would get a gradually creeping out of phase (ie that accumulates). What u should expect is a number of different kinds of (nearnuff) cyclical phase changes, due to a number of effects.  Some changes will have a daily signature (sidereal day of course), some an annual signature (due to Earth's orbit).
6. Why not use one oscillator. Send a signal from the top of a hill -- & then send a signal from lower.  A scope would measure the change in Hz.  But i suppose that the heart of the oscillator would be a quartz crystal – a quartz crystal would be affected (by elevation etc) in ways that u could not ever imagine.
7. But i don’t know much about the accuracy of such instruments. And of course the problems of temperature & air pressure etc. But, even if the instruments were very sensitive (& had zero error etc), u could not imagine the (mainly relativistic) effects & peculiar signals that must happen. It would make an MMX look like child's play.
I would be happy to say more about some of this if desired.
« Last Edit: January 25, 2023, 11:35:25 am by aetherist »
 

Online BrianHG

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Re: DIY measurement of time dilation in a gravity well
« Reply #10 on: January 25, 2023, 05:48:34 pm »
& Einstein was not correct.

So you are telling us that mass and energy do not alter the curvature of spacetime?
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #11 on: January 25, 2023, 07:43:29 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, hence no such thing as spacetime.
Light & em radiation do bend due to the presence of mass (but not due to the presence of energy)(there is no such thing as energy).
Einstein made a correct prediction (re light bending near mass), but for wrong reasons (called equivalence).

If Circlotron send signals to the top of his 100m antenna he will find that he has a big MMX kind of experiment on his hands -- koz electricity on a wire is due to photons (electons) propagating on the surface of the Cu -- & the propagation speed is say 1c/1 in air, & 2c/3 if insulated Cu -- the real problem being that the speed of electricity is affected by the aetherwind blowing throo the antenna -- the aetherwind is say 500 km/s south to north about 20 deg off Earth's axis -- hence the speed of electricity varies during a day (due to Earth's spin & alignment) & during a year (due to Earth's orbit) -- & this is just the start of Circlotron's problems.
 

Offline dietert1

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Re: DIY measurement of time dilation in a gravity well
« Reply #12 on: January 25, 2023, 08:38:31 pm »
This forum member has written lots of nonsense in many threads. There can't be any discussion - he just enjoys provocation and confusion.
Time and energy are extremely useful concepts in physics as is the progress Albert Einstein made long time ago in various areas of physics. General relativity is one of them and there have been several successful experimental verifications. Once more i'd recommend reading Wikipedia instead,

Regards, Dieter
 
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Online BrianHG

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Re: DIY measurement of time dilation in a gravity well
« Reply #13 on: January 25, 2023, 09:18:09 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, hence no such thing as spacetime.

Time and spacetime are not the same thing.  Are you sure you understand what Einstein's General Relativity is?
 

Offline AndyBeez

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Re: DIY measurement of time dilation in a gravity well
« Reply #14 on: January 25, 2023, 09:23:36 pm »
Similar ballpark: The LIGO Laser Interferometer Gravitational-Wave Observatory : https://en.wikipedia.org/wiki/LIGO
 

Offline TimFox

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Re: DIY measurement of time dilation in a gravity well
« Reply #15 on: January 25, 2023, 09:27:53 pm »
Yes, please ignore Aetherist on this subject.
The gravitational red shift ("dropping" a photon down a well) was demonstrated back in 1964 using the Mössbauer effect to detect a small change in the frequency of a gamma photon between the top of a tower and the bottom.
Original reference:  T E Cranshaw and J P Schiffer 1964 Proc. Phys. Soc. 84 245
Later experiments improved this measurement with stronger radioactive sources and a taller tower.
To avoid paywalls, see pp 16-20 of this publication from Argonne National Laboratory, that starts with a discussion of the Mössbauer effect:  https://publications.anl.gov/anlpubs/2005/09/54366.pdf
The Mössbauer effect can detect very small changes in the frequency/energy of a photon emitted from a radioisotope (see the ANL article for the gory details).
It's kinda sorta like detecting an audio-frequency Doppler shift of a gamma photon energy (don't take that sentence literally).
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #16 on: January 25, 2023, 09:30:33 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, hence no such thing as spacetime.
Time and spacetime are not the same thing.  Are you sure you understand what Einstein's General Relativity is?
Yes i have studied (at home) STR & GTR for many years. I made an Excel that showed that an incremental iteration using basic GTR equations did indeed give the "correct" numbers for the bending of light passing the Sun (2 kinds/sets of bendings)(one due to ticking)(one due to contraction of rods)(both equal in total, but having completely different curves along the way).
I daresay that no-one else has made such an Excel.
However the GTR theory for the bending of light passing the Sun is wrong -- & i have used Excel to give the same total bending using aetherwind theory & aether gravity theory (once again 2 kinds of bending here).
 

Online SiliconWizard

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Re: DIY measurement of time dilation in a gravity well
« Reply #17 on: January 25, 2023, 09:31:15 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, (...)

Sure. And this forum doesn't exist. You don't exist. I'm not even replying to this post.
 

Online BrianHG

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Re: DIY measurement of time dilation in a gravity well
« Reply #18 on: January 25, 2023, 09:38:25 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, hence no such thing as spacetime.
Time and spacetime are not the same thing.  Are you sure you understand what Einstein's General Relativity is?
Yes i have studied (at home) STR & GTR for many years.
And after all this study, you don't seem to know that spacetime and time are not the same thing.
Remember, it was Einstein who said that time is nothing more than an illusion, it actually doesn't exist, and yet his General Relativity which he knows is not time has been measured and proven apparently more than you know.
Since you cannot grasp what his 'spacetime' actually is and confused it of being some sort of time, there is nothing here to converse about.
Bye.
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #19 on: January 25, 2023, 09:42:32 pm »
Yes, please ignore Aetherist on this subject.
The gravitational red shift ("dropping" a photon down a well) was demonstrated back in 1964 using the Mössbauer effect to detect a small change in the frequency of a gamma photon between the top of a tower and the bottom.
Original reference:  T E Cranshaw and J P Schiffer 1964 Proc. Phys. Soc. 84 245
Later experiments improved this measurement with stronger radioactive sources and a taller tower.
To avoid paywalls, see pp 16-20 of this publication from Argonne National Laboratory, that starts with a discussion of the Mössbauer effect:  https://publications.anl.gov/anlpubs/2005/09/54366.pdf
The Mössbauer effect can detect very small changes in the frequency/energy of a photon emitted from a radioisotope (see the ANL article for the gory details).
It's kinda sorta like detecting an audio-frequency Doppler shift of a gamma photon energy (don't take that sentence literally).
Yes, Circlotron's antenna signal going up to his/her antenna would indeed be affected by gravitational redshift, & this redshift i suppose can be fairly accurately modelled by GTR.
But this effect (on phase of signal going up to the antenna) is a constant kind of effect & therefor would not affect Circlotron's X – hence this Einsteinian shift can be ignored here.

Are u aware that the Einsteinian shift fails to account for actual delays for signals passing the Sun – it fails by factors of over 1000 – but aether theory accounts for the measured delays. There have been at least 2 such Einsteinian shift failures – if u like i can find them for your info.
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #20 on: January 25, 2023, 09:47:49 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, (...)
Sure. And this forum doesn't exist. You don't exist. I'm not even replying to this post.
The only time that exists is the present instant -- & this instant is universal (ie in our infinite eternal universe).
There is no such thing as Einsteinian time.
The passing of time is an illusion -- albeit one of the great mysteries of life.
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #21 on: January 25, 2023, 09:52:31 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, hence no such thing as spacetime.
Time and spacetime are not the same thing.  Are you sure you understand what Einstein's General Relativity is?
Yes i have studied (at home) STR & GTR for many years.
And after all this study, you don't seem to know that spacetime and time are not the same thing.
Remember, it was Einstein who said that time is nothing more than an illusion, it actually doesn't exist, and yet his General Relativity which he knows is not time has been measured and proven apparently more than you know.
Since you cannot grasp what his 'spacetime' actually is and confused it of being some sort of time, there is nothing here to converse about.
Bye.
I agree with Einstein that time is an illusion -- tho i suppose my illusion is different to his illusion.
I am fairly informed re experiments etc re time (Hafele Keating etc). Thats why i know that GTR & STR are krapp.

Re spacetime. The space bit is about the contraction of rods (ie length) -- the time bit is about the change in ticking of clocks (ie time dilation) or something or everything.
In GTR i suppose that u cant have one (eg LC) without the other (TD).
On the other hand STR depends on velocity -- & GTR depends on mass & velocity -- but i think that all the same u karnt have one (LC) without the other (TD).
« Last Edit: January 25, 2023, 10:07:00 pm by aetherist »
 

Offline aetherist

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Re: DIY measurement of time dilation in a gravity well
« Reply #22 on: January 25, 2023, 09:59:15 pm »
Similar ballpark: The LIGO Laser Interferometer Gravitational-Wave Observatory : https://en.wikipedia.org/wiki/LIGO
LIGO type signals would not come into play in Circloton's X -- hence can be ignored -- or, what i mean is, that there would be no LIGO type signals, ie the signal would be zero, so, no need to ignore.
There are no such things as Einsteinian GWs -- but i think that LIGO can detect some kinds of signals -- not sure what kinds, i would have to have a think about it.
LIGO, being in vacuum, is not like an old fashioned MMX (these worked in gas mode, not vacuum mode). But i would have to have a think. Its complicated, what with hanging mirrors etc.
 

Online SiliconWizard

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Re: DIY measurement of time dilation in a gravity well
« Reply #23 on: January 25, 2023, 10:03:52 pm »
& Einstein was not correct.
So you are telling us that mass and energy do not alter the curvature of spacetime?
There is no such thing as time, (...)
Sure. And this forum doesn't exist. You don't exist. I'm not even replying to this post.
The only time that exists is the present instant -- & this instant is universal (ie in our infinite eternal universe).
There is no such thing as Einsteinian time.
The passing of time is an illusion -- albeit one of the great mysteries of life.

Yes, I already replied to this post. If you see my reply below yours just ignore that. Thanks.
 

Online BrianHG

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Re: DIY measurement of time dilation in a gravity well
« Reply #24 on: January 25, 2023, 10:14:50 pm »
Yes, I already replied to this post. If you see my reply below yours just ignore that. Thanks.
:-DD Don't waste your time on this...
 
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