# Thread: Time Dilation and Gravity

1. A metaphoric experiment if you will that describes this mechanism.

Suppose we had a kiddie train track 100 m long. We place a student school desk that has track wheels attached to it on the track. We attach a digital timer to the desk and of course a drive mechanism that can maintain a constant velocity. On the track we place two switches that are some distance apart. The first turns the digital timer on and the second turns it off. We put a student in the desk and tell him how far apart the switches are and the total mass of his system. We ask the student to calculate his momentum at the end of the run. At the end of the run he gives us a value for his momentum. We move the desk back to the starting point in order to do another run. Unbeknownst to the student I can remotely control the timer. I reduce the rate of the timer by 10% and start the run again. At the end of the run we ask the student which run had the greatest momentum and of course he says the second. Isn't this situation somewhat like a rock sitting on the surface of the earth. The atoms of the rock are vibrating around and colliding with other atoms fields and the atoms clocks are speeding up and slowing down ever so slightly so that the collective momentum of the atoms points to the center of the earth?
Now look at one mole of any element sitting at the surface of the Earth. Now imagine the atoms of the element traveling back-and-forth on trillions of our little kiddie train tracks, Their tiny clocks speeding up and slowing down as they move up and down in the gravity well. I do not possess the mathematical skills to test this hypothesis but using Avogadro's number it should be possible to calculate the weight of one mole which should be equal to the mass of one mole. As for inertia, if you take the same one mole far out into space where there is very little gravity and give it a one gee acceleration the atoms clocks do just as they did on Earth with the momentum being opposite the direction of acceleration, hence inertia.  2. Hello again! Originally Posted by bird11dog A metaphoric experiment if you will that describes this mechanism.

Suppose we had a kiddie train track 100 m long. We place a student school desk that has track wheels attached to it on the track. We attach a digital timer to the desk and of course a drive mechanism that can maintain a constant velocity. On the track we place two switches that are some distance apart. The first turns the digital timer on and the second turns it off. We put a student in the desk and tell him how far apart the switches are and the total mass of his system. We ask the student to calculate his momentum at the end of the run. At the end of the run he gives us a value for his momentum. We move the desk back to the starting point in order to do another run. Unbeknownst to the student I can remotely control the timer. I reduce the rate of the timer by 10% and start the run again. At the end of the run we ask the student which run had the greatest momentum and of course he says the second.
OK, although you have of course deliberately tricked the student into giving the wrong answer. None of this changes what the student's momentum (relative to the Earth) actually is, so it isn't quite the same thing as time dilation. Originally Posted by bird11dog Isn't this situation somewhat like a rock sitting on the surface of the earth. The atoms of the rock are vibrating around and colliding with other atoms fields and the atoms clocks are speeding up and slowing down ever so slightly so that the collective momentum of the atoms points to the center of the earth?
If the rock is sitting on the Earth's surface, the total (collective) momentum relative to the Earth's surface is necessarily zero. If the rock's total momentum really is pointing toward the centre of the Earth, the rock must be sinking, or falling down a hole. Originally Posted by bird11dog Now look at one mole of any element sitting at the surface of the Earth. Now imagine the atoms of the element traveling back-and-forth on trillions of our little kiddie train tracks, Their tiny clocks speeding up and slowing down as they move up and down in the gravity well.
If you mean the atoms' clocks as judged by some stationary observer on the surface, then sure; in fact, not only do the atoms' clocks get affected by the gravitational field, they also get affected by special relativistic effects (SR time dilation). For the Earth's atmosphere, the fractional difference in clock rate for an atom at the surface vs. an atom at an altitude of 10 km is around 1 part in 1012, and the typical time dilation due to thermal motion at the surface is of the same order of magnitude. Originally Posted by bird11dog I do not possess the mathematical skills to test this hypothesis but using Avogadro's number it should be possible to calculate the weight of one mole which should be equal to the mass of one mole. As for inertia, if you take the same one mole far out into space where there is very little gravity and give it a one gee acceleration the atoms clocks do just as they did on Earth with the momentum being opposite the direction of acceleration, hence inertia.
Are you saying we can start with no knowledge of a particle's mass, and somehow compute the weight of a mole of such particles? That would be an impressive trick, but to be honest I don't see how it could be done. There isn't enough information.

Maybe I've misunderstood your idea?  3. To be honest I am not sure I understand the connection between the OP and gravity either. However, I think it deserves to be mentioned that there are two distinct notions of time dilation - there is relative time dilation ( which is a coordinate time effect induced by relative motion ), and there is gravitational time dilation ( which is a proper time effect due to sources of energy-momentum ). These are physically distinct phenomena, and not to be confused with one another.  4. Maybe you didn't, let me work on a better presentation. Well post it tomorrow. Thanks for the response.  5. Imagine an atom that can only vibrate in the up and down direction. Hopefully we can assume that the atom has a time of its own, a clock so to speak and as it vibrates in the down direction that clock slow's and in the up direction it speeds up. When the atom vibrates in the down direction it's momentum will be p = md/t. We can see that as time slows the value for P increases. Obviously we can see as the atom vibrates in the up direction the value for P decreases. Now as we tilt the line of vibration toward the horizontal the difference between the P up and P down becomes smaller and smaller. Why would not the sum of all the momentum's of atoms in an object simply produce the weight of that object? Doesn't this idea also show why we cannot tell the difference between gravity and inertia? A really good thing about this idea is that it removes the need for QM to explain gravity.  6. Obviously Markus I claim you're wrong about two different types of time dilation because all relative motion is caused by acceleration somewhere along the line otherwise there would have been no relative motion. Back to the OP. My argument is based on the fact that time dilation occurs no matter how short the motion and the fact that the equation for momentum is well tested. As to why time dilation occurs I don't know. We are so locked into the standard model that I seriously doubt we will ever know. If the time however comes when we understand how energy is put together to make the proton and electron maybe we will.  7. Obviously Markus I claim you're wrong about two different types of time dilation
You are of course free to claim anything you like, yet the fact remains that they are physically distinct effects. Gravitational time dilation affects accumulated proper time and depends on the entire history ( world line ) of a test particle, whereas relative time dilation affects coordinate time and is an instantaneous relationship between frames, independent of prior history. The two can occur simultaneously, but they need to be accounted for separately; the most straightforward example would be the on-board clock of an orbiting satellite :

http://www.triangulum.nl/Werkgroepen...PS%20essay.pdf

Any good textbook on relativity will further explain this distinction in-depth - if you like I can give you some recommendations for good study material on the subject matter.

because all relative motion is caused by acceleration somewhere along the line otherwise there would have been no relative motion
Yes, the acceleration phases are reflected in the geometry of a test particle's world line; it's total length is just precisely the accumulated proper time between two events.

We are so locked into the standard model that I seriously doubt we will ever know.
It would seem to me we have a very good model to explain why and how time dilation in both its forms comes about. It is really very straightforward.  8. My argument is based on the fact that time dilation occurs no matter how short the motion(the bouncing around of atoms up and down and sideways) and the fact that the equation for momentum(pdown = md/t > pup = md/t) is self evident as long as the former is true and no one, as of yet, has falsified either. As to why time dilation occurs I don't know. We are so locked into the standard model that I seriously doubt we will ever know. If the time however comes when we understand how energy is put together to make the proton and electron maybe we will.  9. We cannot allow any new ideas because it threatens the banging of our own drum huh Markus. If you think you have shown where the idea fails at, that is very sad.  10. Originally Posted by bird11dog My argument is based on the fact that time dilation occurs no matter how short the motion(the bouncing around of atoms up and down and sideways) and the fact that the equation for momentum(pdown = md/t > pup = md/t) is self evident as long as the former is true and no one, as of yet, has falsified either.
I'm sure I addressed that earlier. Given that the box is resting on the surface, the net momentum of the gas in the box must be zero, and so not pointing in any particular direction.  11. Wow, and you obviously think you've answered the question.  12. We cannot allow any new ideas
Of course we can - that is specifically what this section "Personal Theories and Alternative Hypotheses" is here for, so I am not sure what you are trying to imply. You are free to present any idea you like here, but given that this is a mainstream forum, such ideas will be evaluated in light of current scientific understanding.

If you think you have shown where the idea fails at, that is very sad.
I and others have merely given you the feedback you asked for; was that not the purpose of you posting here, to obtain feedback for your idea ? I hope it was, because that is what this section is here for. I'm sorry if you don't like what we wrote, but I would suggest you take it in a constructive way and use it as an opportunity to improve your hypothesis. If on the other hand your expectation was that we all agree with any new ideas and hypotheses that are being put forward here, then I must disappoint you. You also appear to be under the impression that we are under some sort of obligation to proof you wrong - I don't understand this, since the idea is yours, so it is up to yourself to show everyone else how and why it is better than established physics, and not the other way around.  13. Originally Posted by bird11dog
I reduce the rate of the timer by 10% and start the run again. At the end of the run we ask the student which run had the greatest momentum and of course he says the second.
That is incorrect. If you reduce the rate of the clock then the momentum will appear to be less than the first time, not greater. The rate at which a clock runs is inversely proportional to the period between ticks of the clock. E.g. suppose that the first time the train takes 100 seconds to move 100 meters. Then the initial speed is dx/dt = (100 meters)/(100 seconds) = 1 meter/second = 1 m/s. Now we reduce the rate at which the clock ticks. That means it ticks 10% slower than before. So it takes 10% longer between ticks of the clock. So instead of the clock reading 100 seconds it will instead read 110 seconds. The speed is then (100 meters)(110 seconds) = 0.91 m/s. Therefore he thinks his momentum decreased. However this is but a mere illusion. It cant be taken to be gravitational time dilation, thats for sure. And its going to slow to taken as time dilation due to motion. However since you didnt specify how long it takes to travel that 100 meters we cant make that determination. However there was exactly zero change in momentum. The only thing that happened was that there was a bad clock in use. Originally Posted by bird11dog
Isn't this situation somewhat like a rock sitting on the surface of the earth.
No. The train has a non-zero net momentum as measured from the Earths frame of reference whereas the rock is at rest and its momentum is zero. Originally Posted by bird11dog
The atoms of the rock are vibrating around and colliding with other atoms fields and the atoms clocks are speeding up and slowing down ever so slightly so that the collective momentum of the atoms points to the center of the earth?
No. The net momentum of the rock is zero so the momentum vector doesnt point anywhere since the zero vector doesnt have a direction. Originally Posted by bird11dog
Now look at one mole of any element sitting at the surface of the Earth. Now imagine the atoms of the element traveling back-and-forth on trillions of our little kiddie train tracks, Their tiny clocks speeding up and slowing down as they move up and down in the gravity well.
How are they moving up and down in the gravity well? I thought that the rocks were at rest on the Earth? Originally Posted by bird11dog
I do not possess the mathematical skills to test this hypothesis but using Avogadro's number it should be possible to calculate the weight of one mole which should be equal to the mass of one mole.
To know the weigtht of one mole you need to know the mass per mole. From that you use Avogadro's number to determine the mass and then use that to determine the weight. You dont determine the mass from the weight because you only get the mass from Avogadro's number, not the weight. Originally Posted by bird11dog
As for inertia, if you take the same one mole far out into space where there is very little gravity and give it a one gee acceleration the atoms clocks do just as they did on Earth with the momentum being opposite the direction of acceleration, hence inertia.
Where did you get that idea? A rock sitting on the Earths surface is not accelerating. Its at rest. The only thing thats accelerating is when you look at this from the point of view of general relativity (GR). From that point of view there is a freely falling frame S which is a locally inertial frame of reference (aka a free float frame) that is accelerating in the z direction. The surface of the Earth is accelerating in the +z direction relative to the free-float frame. You misinterpreted GR and thats how youre getting things mixed up. No worries though. Its a common misinterpretation.

If the matter starts out from rest then as it accelerates the momentum increases. The direction of the momentum will then be in the direction of the acceleration, not the other way around. E.g. Consider the inertial frame S that has Cartesian coordinates labeled (x, y, z). Let there be a particle at the origin that is at rest. At t = 0 it starts accelerating at a rate of 1g = 9.8 m/s^2 in the +x direction. As its speed increases the velocity will also at all times point in the +x direction and thus the momentum will be as well. Therefore the acceleration points in the same direction as the momentum.  Posting Permissions
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