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Author Topic: Does the internal clock speed up or slow down as relative velocity increases?  (Read 5886 times)

Offline jerrygg38

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From relativity does the internal clock in a spaceship speed up or slow down as the relative velocity increases?
    The experiments of the effect of the frequency of a clock relative to the source of gravity shows that the frequency decreases or red shifts as the clock moves away from a stronger gravitational field toward a weaker gravitational field. At the same time the clock will tend to expand as the gravitational pressure decreases. That makes sense. Above the Earth we have a time clock stationary with respect to us and it is observed to run slower. The gravitational gradient will account for this. Although the clock is running very fast around the center of the Earth, it is not really moving with respect to the Earth’s gravitational field. So it seems to me that only the gravitational field gradient counts. Is that correct?
  The other problem is that if we have a spaceship or crystal clock moving away from the Earth at high speed, the object should shrink with velocity. This would seem to make the clock speed up since its energy has risen and it has shrunk. Yet it is confusing as some feel that processes slow with velocity. Does the clock speed up or slow down? What is the explanation that makes sense?
« Last Edit: 12/09/2016 09:25:48 by chris »


 

Offline Colin2B

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Although the clock is running very fast around the center of the Earth, it is not really moving with respect to the Earth’s gravitational field. So it seems to me that only the gravitational field gradient counts. Is that correct?
No. See https://en.m.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment
 

Offline alancalverd

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Lots of incorrect statements in the OP, so let's begin with a sign correction and some observed facts.

1. Gravitational potential has a maximum value of zero in deep space, far from any mass. It decreases as you approach a massive body. This sign convention makes sense because (a) the only universal reference point is "no mass nearby" and (b) as a particle falls towards a large body it loses potential and gains kinetic energy, so the potential near a large body must be less than in deep space. 

2. A stationary clock at altitude is observed to run faster than a reference clock on the ground, not slower.

3. A moving clock is observed to run slower than a reference clock.

The key word here is "observed" , the implication being that the observer is stationary and close to the reference clock.

Thus there is no implication (or indeed physical possibility) that an observer next to the high-altitude or moving clock will consider his clock to be performing oddly. On the contrary he sees the "ground" clock as going slower in both cases.

It's important to distinguish between the two cases. In the case of gravitational potential, there is a hypothetical general and universal reference - any "deep space" position where the gravitational potential is zero. Thus the clock on the surface of a planet is at a "special" position (defined by the gravitational field vector) and it is hardly surprising that it behaves differently from all the "deep space" clocks.

In the matter of moving clocks, there is no universal reference or special position: all motion is relative between the two bodies, so whether you are on the surface of the planet or in a plane, the other clock is moving at the same observed speed, so the timing anomaly must be the same in either direction of observation.     

 

Offline alancalverd

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And yet the result is exactly what you would calculate from first principles in the absence of an aether. The Court calls William of Ockham as an expert witness....
 

Offline puppypower

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Why do clocks, made of matter, run faster at altitude compared to the surface; faster frequency, while energy moving in the same direction will red shift; lower frequency?

 

Online evan_au

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Quote from: puppypower
Why do clocks, made of matter, run faster at altitude compared to the surface; faster frequency, while energy moving in the same direction will red shift; lower frequency?
If you want to talk about the rate of clocks:-
- You could consider that an atom is like a clock - the light emitted is of a particular frequency, dictated by the permitted energy levels of the electrons.
- Time will flow more slowly for an atom deep in a gravitational well; this means that the photon will have a lower frequency
- Time will flow more rapidly far outside the gravitational well; this means that the clock "ticks" more rapidly, and the photon emitted by the same type of atom will be seen to have a higher frequency than one emitted deep in the gravitational well.

These atoms are both made of matter. I see no conflict.
 

Offline alancalverd

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Why do clocks, made of matter, run faster at altitude compared to the surface; faster frequency, while energy moving in the same direction will red shift; lower frequency?

Imprecise thinking. The higher altitude clock runs faster as seen from the ground. A photon emitted from higher altitude undergoes a blue shift as seen from the ground. Same physics, same result.
 

Offline jerrygg38

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Thanks for the answers.However every article I read and every opinion I read always results in alternate answers. I try to get some rules in my head and every time I think I have the rules, they are always at odds with other. It seems to me that my effort to understand both the clock variation with gravity and with motion are not easy to set up. Yesterday I came to the conclusion that the gravitational issue is one in which energy spherically enters a clock or atom and is basically a simple problem. The velocity issue involves linear energy added to spherical confined energy (mass). This issue involves measurements of distances verses light speed. Thus this involves Einstein"s special relativity type solution. Two different things are involved and each has different conclusions. Thus it is not correct to use the same rules for both cases. Do you agree?
 

Offline Atkhenaken

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The Hafele–Keating experiment which demonstrates that two aircraft traveling in different directions around the Earth at a constant velocity will arrive back at different times. This experiment was supposed to prove that relativity is correct. Well, this is a very poor experiment when you consider that the wind variation alone would make any result null and void. Yet, amazingly, they came up with a result which favoured relativity. Now, consider that both planes were traveling at the same velocity and the atomic clocks had a slight difference at the end of their journey. Now, relativity requires that one of the craft be flying at a faster velocity to satisfy the time dilation hypothesis. But, unfortunately, this wasn't the case. Yet, this experiment has been hailed as one of the great proofs that relativity is a valid theory. lol!

Note - Einstein even thought that two different clocks placed at the equator and North Pole would show different times also. lol! Nincompoop!
 

Offline jerrygg38

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Lots of incorrect statements in the OP, so let's begin with a sign correction and some observed facts.

1. Gravitational potential has a maximum value of zero in deep space, far from any mass. It decreases as you approach a massive body. This sign convention makes sense because (a) the only universal reference point is "no mass nearby" and (b) as a particle falls towards a large body it loses potential and gains kinetic energy, so the potential near a large body must be less than in deep space. 

2. A stationary clock at altitude is observed to run faster than a reference clock on the ground, not slower.

3. A moving clock is observed to run slower than a reference clock.

The key word here is "observed" , the implication being that the observer is stationary and close to the reference clock.

Thus there is no implication (or indeed physical possibility) that an observer next to the high-altitude or moving clock will consider his clock to be performing oddly. On the contrary he sees the "ground" clock as going slower in both cases.

It's important to distinguish between the two cases. In the case of gravitational potential, there is a hypothetical general and universal reference - any "deep space" position where the gravitational potential is zero. Thus the clock on the surface of a planet is at a "special" position (defined by the gravitational field vector) and it is hardly surprising that it behaves differently from all the "deep space" clocks.

In the matter of moving clocks, there is no universal reference or special position: all motion is relative between the two bodies, so whether you are on the surface of the planet or in a plane, the other clock is moving at the same observed speed, so the timing anomaly must be the same in either direction of observation.   
  Ok seems to agree with most articles of wikopedia you guys presented. The only thing that bothers me is this statement:
   Stationary Clocks higher above the earth run faster but emitted photons from atomic clocks or atoms above the earth produce lower energy photons with lower frequencies. Is this correct? Within the sun the photons are higher frequencies and on the surface lower frequencies. It seems the clock is faster near the surface but the frequencies emitted are lower. Is this correct and if so it seems strange to me?
 

Offline alancalverd

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   Stationary Clocks higher above the earth run faster but emitted photons from atomic clocks or atoms above the earth produce lower energy photons with lower frequencies. Is this correct?

No. The emitted frequency of anything, as measured by an observer at the same gravitational potential,  is unchanged by position. The energy of a photon increases as it falls down a potential well (blue shift). So if your high-altitude clock is emitting a red photon every second, the observer on the ground* sees a blue photon every 0.9 seconds according to his clock. 

*or rather, on the surface of a really enormous planet. The shifts are quite tiny in earth gravity.
 

Offline jerrygg38

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   Stationary Clocks higher above the earth run faster but emitted photons from atomic clocks or atoms above the earth produce lower energy photons with lower frequencies. Is this correct?

No. The emitted frequency of anything, as measured by an observer at the same gravitational potential,  is unchanged by position. The energy of a photon increases as it falls down a potential well (blue shift). So if your high-altitude clock is emitting a red photon every second, the observer on the ground* sees a blue photon every 0.9 seconds according to his clock. 


*or rather, on the surface of a really enormous planet. The shifts are quite tiny in earth gravity.
Thanks for explaining Einsteins theory better.  I got a picture of what you guys say. Now I have to try to understand how the gravitational field works to produce this effect. All I can think of is gravitational field density such that the ruler shrinks. Einstein uses time and I wonder if the shrinkage of the ruler produces the same results as time for a constant light speed condition. I can picture ruler shrinkage but cannot picture time shrinkage or elongation physically. Are they the same?
« Last Edit: 11/09/2016 20:23:08 by jerrygg38 »
 

Online evan_au

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Quote from: jerrygg38
Within the sun the photons are higher frequencies and on the surface lower frequencies.
Perhaps you are confusing temperature and time dilation?
- Near the center of the Sun, the temperature is millions of degrees. The average frequency of radiation is very high (X-Ray or gamma ray region)
- The surface of the Sun has a temperature of thousands of degrees. The average frequency of radiation is in the visible spectrum.

When you compare the frequency of radiation at the top and bottom of a gravitational well, you must use radiation from the same kind of atom, under the same temperature and pressure and stimulus (eg electrical discharge).

Quote
I can picture ruler shrinkage but cannot picture time shrinkage or elongation physically. Are they the same?
When you measure the frequency of light (cycles per second), you measure time dilation.
When you measure the wavelength of light (wavelengths per meter), you would measure length compression.

Compared to light emitted by an observer outside a gravitational well, an observer at the bottom of the well would see:
- The frequency of light has increased (bluer), because his clock is running more slowly
- The wavelength of light has decreased, because the photons are bluer.

Stationary observers do not experience length contraction. If the observer in the gravitational well had his ruler compressed, he would measure more wavelengths per meter, which is the opposite of what is observed.

Remember: Special relativity deals with moving observers, in the absence of a gravitational field.
- General relativity adds in considerations of both gravity and motion.

Quote from: Atkenaten
Now, consider that both planes were traveling at the same velocity and the atomic clocks had a slight difference at the end of their journey.
This is a very geocentric view.
In fact, one plane was traveling with the rotationof the Earth, so their velocities added.
The other was travelling against the rotation of the Earth, so their velocities subtracted.

In fact, much more precise proofs of general relativity are in operation every time you use your GPS. It would be unusable if they did not take into account both the velocity of the satellite, and its position in Earth's gravitational well.
 

Offline Atkhenaken

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Quote from: Atkenaten
Now, consider that both planes were traveling at the same velocity and the atomic clocks had a slight difference at the end of their journey.
Quote
This is a very geocentric view.
In fact, one plane was traveling with the rotationof the Earth, so their velocities added.
The other was travelling against the rotation of the Earth, so their velocities subtracted.

In fact, much more precise proofs of general relativity are in operation every time you use your GPS. It would be unusable if they did not take into account both the velocity of the satellite, and its position in Earth's gravitational well.

You have added the rotation of the Earth into the equation. This is very naughty. The rotation of the Earth doesn't affect the velocity of the plane because the atmosphere moves at the same speed as the Earth's rotation.
 

Offline alancalverd

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This baffled me for a while until I realised that I was making an unjustified assumption that the clocks were all at the same latitude. If the planes were flying around the equator and the reference clock was at the north pole, one plane would be travelling about 2000 mph faster than the other relative to the reference clock.
 

Offline jerrygg38

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This baffled me for a while until I realised that I was making an unjustified assumption that the clocks were all at the same latitude. If the planes were flying around the equator and the reference clock was at the north pole, one plane would be travelling about 2000 mph faster than the other relative to the reference clock.
  I have added another question in this regard.
    As the Earth spins we have a rotating gravitational field. The atmosphere rotates with it. A satellite spinning around the center of the Earth can be stationary with respect to the field. Thus it can be stationary with respect to a clock right below it. Then it would only need gravitational corrections and not velocity corrections for the clock below. At the North Pole the satellite at the equator would be moving faster and corrections would be necessary.
   In the literature specified herein, it is said that the surface of the Earth is an equal time entity. Thus a clock at the North Pole and a clock at the equator will read exactly the same. Thus velocity and gravitational corrections balance out. What do they mean by that? Am I correct to assume they mean the mean water level all around the Earth?
« Last Edit: 12/09/2016 13:51:22 by jerrygg38 »
 

Online evan_au

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Quote from: jerrygg38
A satellite spinning around the center of the Earth can be stationary with respect to the field. Thus it can be stationary with respect to a clock right below it. Then it would only need gravitational corrections and not velocity corrections for the clock below.
I'm afraid not.
- An observer on the equator will be traveling at 40,000km/24 hours = 1,700 km/hour
- A satellite directly above, in geosynchronous orbit, will be traveling at 265,000km/24 hours = 11,000 km/hour

So you need to correct for both speed and depth in the gravitational well.

The Earth's gravitational field is not an inertial frame of reference from which you can measure the position of the (rotating) person and satellite.
 

Offline jerrygg38

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Quote from: jerrygg38
A satellite spinning around the center of the Earth can be stationary with respect to the field. Thus it can be stationary with respect to a clock right below it. Then it would only need gravitational corrections and not velocity corrections for the clock below.
I'm afraid not.
- An observer on the equator will be traveling at 40,000km/24 hours = 1,700 km/hour
- A satellite directly above, in geosynchronous orbit, will be traveling at 265,000km/24 hours = 11,000 km/hour

So you need to correct for both speed and depth in the gravitational well.

The Earth's gravitational field is not an inertial frame of reference from which you can measure the position of the (rotating) person and satellite.
   Thanks. I was trying to relate things to the Earths gravitational field which to me is rotating as the Earth rotates. So you say that is not true and the only thing important is the clock on the earth and the clock in the sky. And the relative direction of the velocity vector will depend upon where on Earth you are. Yet I guess this will be constant for the Geo-synchronous orbit.
   It seems to me that the Earth clock relates to the Earths gravitational field and so does the satellites clock. Thus they are conditioned by the Earths gravitational field. But this must be equalized such that it appears that both clocks relate to each other as if the Earths field did not count.
   I wonder if relativity would work in an area of space with almost no gravitational field.
 

Online evan_au

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Quote from: jerrygg38
I wonder if relativity would work in an area of space with almost no gravitational field?
This is the basic premise of Einstein's Special Theory of Relativity. It examined the effects of motion through spacetime, away from any gravitational fields.

His later work, the General Theory of Relativity added in the effects of gravitational fields. This is more complicated; it built on his earlier work and took longer to develop.
 

Offline Atkhenaken

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Quote from: jerrygg38
I wonder if relativity would work in an area of space with almost no gravitational field?
This is the basic premise of Einstein's Special Theory of Relativity. It examined the effects of motion through spacetime, away from any gravitational fields.

His later work, the General Theory of Relativity added in the effects of gravitational fields. This is more complicated; it built on his earlier work and took longer to develop.

You have mentioned "space-time" which is short for 'space-time continuum' which is a modern name for the old 'aether'. Thus, ColinB2 would not be pleased! "Off to the forum dungeon with you, uncouth peasant!" He would say.
 

Offline alancalverd

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You have mentioned "space-time" which is short for 'space-time continuum' which is a modern name for the old 'aether'.

Not in my language. Nor in any of the classical electromagnetism textbooks, or Einstein's papers.

If you were confined to the dungeon, it would be for dishonesty, the worst crime in science.
 

Offline jerrygg38

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Quote from: jerrygg38
I wonder if relativity would work in an area of space with almost no gravitational field?
This is the basic premise of Einstein's Special Theory of Relativity. It examined the effects of motion through spacetime, away from any gravitational fields.

His later work, the General Theory of Relativity added in the effects of gravitational fields. This is more complicated; it built on his earlier work and took longer to develop.
  Thanks. I always study alternative ideas. Right now I am studying the time dimension which I believe in but have never used  in any way. So Einstein eliminated the gravitational field in pure outer space which messes up my thought process for my interactions between things and has reduced the universe to interactions in time.
   So now besides gravitational waves I will have to consider time waves. Wow! New possibilities. Has anyone spoke of time waves?
 

Offline Atkhenaken

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You have mentioned "space-time" which is short for 'space-time continuum' which is a modern name for the old 'aether'.

Not in my language. Nor in any of the classical electromagnetism textbooks, or Einstein's papers.

If you were confined to the dungeon, it would be for dishonesty, the worst crime in science.

Dungeons are for people who displease the king. Not for dishonesty. You can't become a king without being dishonest. Einstein stole all his ideas from other people, including his wife. Thus, by being dishonest, he became a king of the physics world.
 

Offline jeffreyH

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You have mentioned "space-time" which is short for 'space-time continuum' which is a modern name for the old 'aether'.

Not in my language. Nor in any of the classical electromagnetism textbooks, or Einstein's papers.

If you were confined to the dungeon, it would be for dishonesty, the worst crime in science.

Dungeons are for people who displease the king. Not for dishonesty. You can't become a king without being dishonest. Einstein stole all his ideas from other people, including his wife. Thus, by being dishonest, he became a king of the physics world.

I think you may have displeased Elvis, king of rock n' roll. He is reading this after his shift at the chip shop. He doesn't approve of the way you are talking about his mate Einstein. He thinks your ideas are pants BTW.
 

Offline alancalverd

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Interesting that none of Einstein's victims managed to publish before him. Did he kill them as well as pinch their work? 
 

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