about Bob's article on absolute or relative time

[ThePhy]

The two clocks are affected in the same way, by gravity

The two clocks are not affected to the same degree, by gravity.

An apple falling to the ground and the moon orbiting the Earth are related in a similar way. They are both gravity driven effects, but the resulting observations are different due to the different physical setups.

This is simple physics, uh, ThePhy.

Right, simple physics. Your choice of a falling apple and the moon orbiting the earth is instructive, since both of those are governed by exactly the same law. Put the apple at the moon’s orbital distance and speed, and it would follow the path the moon does.

As already shown, this is exactly what is not true between a gravity clock and a cesium clock. Put in a similar situation of reduced gravity, one will give results highly discordant with the other.

What does that name mean, anyway?

That is exactly right.

 

[Flipper]

The exact same calculations are possible by assuming that gravity is affecting the clock.

Um, no they aren't. Quite aside from the applied assumption that physicists are unable to calculate and therefore account for the effects of general relativity before doing the experiment, it has been also done with multiple clocks at the same altitude. If they're at the same altitude, perhaps you can explain how gravity affects them differently?

Furthermore, relativistic time dilation has been measured in particle accelerators where very concentrated beams of particles are accelerated to very high speeds across flat trajectories and exceed their observed decay rates at rest over relativistically predictable distances. I would like to to know how you could account for that with gravity.

Similar time dilation effects have been observed in the constant rain of muon particles caused by interactions in the upper atmosphere. Scientists have observed the decay time for such a particle at sea level. Yet detectors track a much larger number of muons than their particle decay rates should allow.

The excess of particles is explained by relativistic time dilation - they are traveling close to the speed of light and from our perspective of their frame of reference, time passes much slower.

So now its my turn.

First, explain the results above in terms of gravity.

Second, why don't you explain to us in a bit more detail how gravity works on atomic clocks and what the key differences are between your explanation and that of general and special relativity?

 

[Flipper]

And?

And what? You could read the paper online for yourself1 and decide whether you think Einstein was talking about the relativity of time.


1 Hypothetically speaking, anyway. We both know you won't.

 

[Nick M]

Well both special and general relativity require relative time.

So they are both wrong? I always knew that Tesla and Newton have more sense.

So, lets go back to the begining, before the Clintonesque double talk started.

The clock being a day ahead dosn't mean that it's in the future.

I would agree. And that is the point of the OP. The clock is not in a different time. Or is fool wrong? He isn't.

Thats like making an arbitrary distinction between length and the measurement of length. There is no quantitative difference between the measurement of time and the passage of time..

So, which one of you is right?

They aren't the physical manifestations of a phenomena called "time", they're just mechanical devices constructed to represent a human idea.

That isn't what Jukia said. So you agree with fool?

 

[Lighthouse]

And what? You could read the paper online for yourself1 and decide whether you think Einstein was talking about the relativity of time.


1 Hypothetically speaking, anyway. We both know you won't.

:bang:

Not the issue at all. The issue is that it is not necessary for time to be relative in order for speed to be relative. Or for temperature to be relative. Or for anything else to be relative for that matter.

 

[dan1el]

So they are both wrong? I always knew that Tesla and Newton have more sense.

So, lets go back to the begining, before the Clintonesque double talk started.

Fun fact: If relativistic effects hadn't been taken into consideration, GPS would be offset by about 10 kilometers per day.

 

[Johnny]

Which part of the Bible does relativity clash with?

 

[Stripe]

Right, simple physics. Your choice of a falling apple and the moon orbiting the earth is instructive, since both of those are governed by exactly the same law. Put the apple at the moon’s orbital distance and speed, and it would follow the path the moon does.

Would it? I don't think it would. Take the sun as a universal point of reference. The Earth-moon interplay would not remain as it is from the vantage point of the sun were the moon to be replaced with a standard apple, would it?

As already shown, this is exactly what is not true between a gravity clock and a cesium clock. Put in a similar situation of reduced gravity, one will give results highly discordant with the other. That is exactly right.

That's because the mechanical features of the two are remarkably different. And I'm not arguing with you. They will show disconcordant responses. But the experiment we are dealing with measures the effect on identical items. Two atomic clocks, one at sea level and one on a mountain, show different measures of time. This is because the different gravitational effects on the clocks.

 

[Stripe]

Um, no they aren't. Quite aside from the applied assumption that physicists are unable to calculate and therefore account for the effects of general relativity before doing the experiment, it has been also done with multiple clocks at the same altitude. If they're at the same altitude, perhaps you can explain how gravity affects them differently?

I don't know what you're saying :idunno:

Furthermore, relativistic time dilation has been measured in particle accelerators where very concentrated beams of particles are accelerated to very high speeds across flat trajectories and exceed their observed decay rates at rest over relativistically predictable distances. I would like to to know how you could account for that with gravity.

That's nice. We're not dealing with a change in velocity (although velocity and gravity are invariably linked). We're dealing with a change in gravity.

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/muon.html

First, explain the results above in terms of gravity.

They likely aren't. I'm not questioning those experiments. I'm dealing with the one in the opening post.

Second, why don't you explain to us in a bit more detail how gravity works on atomic clocks and what the key differences are between your explanation and that of general and special relativity?

I don't know how gravity affects atomic clocks. My explanation (that Pastor Enyart made me aware of) is that gravity affects the clock. An explanation from relativity says that gravity stretches time for one clock and not the other.

 

[ThePhy]

:bang:

Not the issue at all. The issue is that it is not necessary for time to be relative in order for speed to be relative. Or for temperature to be relative. Or for anything else to be relative for that matter.

One of Einstein’s teachers was Hermann Minkowski. Years after he had Einstein as a student, Einstein put forth his Special Theory of Relativity. Minkowski became active in understanding what that theory meant, and in 1908 said:

…space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.

Ever since it has been recognized that changes in motion are fundamentally intertwined with corresponding changes in the flow of time.

 

[Lighthouse]

One of Einstein’s teachers was Hermann Minkowski. Years after he had Einstein as a student, Einstein put forth his Special Theory of Relativity. Minkowski became active in understanding what that theory meant, and in 1908 said: Ever since it has been recognized that changes in motion are fundamentally intertwined with corresponding changes in the flow of time.

And Minkowski was just as wrong as Einstein.

 

[Stripe]

Which part of the Bible does relativity clash with?

It clashes with good science.

 

[ThePhy]

Would it? I don't think it would. Take the sun as a universal point of reference. The Earth-moon interplay would not remain as it is from the vantage point of the sun were the moon to be replaced with a standard apple, would it?

I have no idea what you are getting at by referring to the sun as a point of reference.

But anyway, replacing the moon with an apple would modify the earth-moon interface, simply because of the enormous change of mass in going from the moon to the apple. But that mass change is already accounted for the Newton’s laws, so as understood from the viewpoint of Newtonian physics, the same laws determine the apple’s orbit as determine the moon’s orbit. There would probably be two significant changes due to an apple moon – the tides would effectively cease, and barring one heck of a good telescope, you wouldn’t see the apple moon in orbit.

That's because the mechanical features of the two are remarkably different. And I'm not arguing with you. They will show disconcordant responses. But the experiment we are dealing with measures the effect on identical items. Two atomic clocks, one at sea level and one on a mountain, show different measures of time. This is because the different gravitational effects on the clocks.

Good, now we can drop the erroneous idea that there is a corresponding effect of changed gravity on the two types of clocks, and compare oranges with oranges.

As dan1el noted, the GPS satellites have to compensate for general relativistic effects in their software. Every time you look at a GPS display, you are demonstrating the correctness of the Einstein concepts.

 

[ThePhy]

And Minkowski was just as wrong as Einstein.

I take it that the sum of the substance you are going to offer is "I don't believe it"?

 

[Stripe]

I have no idea what you are getting at by referring to the sun as a point of reference.

Just trying to throw you off guard

But anyway, replacing the moon with an apple would modify the earth-moon interface, simply because of the enormous change of mass in going from the moon to the apple. But that mass change is already accounted for the Newton’s laws, so as understood from the viewpoint of Newtonian physics, the same laws determine the apple’s orbit as determine the moon’s orbit. There would probably be two significant changes due to an apple moon – the tides would effectively cease, and barring one heck of a good telescope, you wouldn’t see the apple moon in orbit.

The apple would not retain the same orbit.

Good, now we can drop the erroneous idea that there is a corresponding effect of changed gravity on the two types of clocks, and compare oranges with oranges.

Why? Gravity affects atomic clocks just as it affects water clocks. Why would I drop that idea? The observations back it up nicely.

As dan1el noted, the GPS satellites have to compensate for general relativistic effects in their software. Every time you look at a GPS display, you are demonstrating the correctness of the Einstein concepts.

They have to compensate for gravity (and probably velocity).

 

[dan1el]

It clashes with good science.

How the hell would you know?

 

[ThePhy]

… The apple would not retain the same orbit.

Don’t understand orbital mechanics very well, do you? Watch an astronaut working outside on a many-ton space station in orbit. When he gently lets a one-ounce tool loose it floats right along in the same orbit as the monstrous structure that it is now totally disconnected from.

Why? Gravity affects atomic clocks just as it affects water clocks. Why would I drop that idea? The observations back it up nicely.

I will admit that I really thought you understood the difference between the effects of gravity on the two dissimilar types of clocks. But alas, just like Huck Finn’s dad, I suspect the only thing that might keep you from regressing at the first opportunity (or getting dead drunk in the case of Huck’s dad) is a shotgun.

They have to compensate for gravity (and probably velocity).

The compensation is via relativistic equations, which include distortions in the flow of time.

 

[dan1el]

The apple would not retain the same orbit.

The gravitational force F between the Earth (mass M) and an orbiting mass m is given by
F = G M m/r^2 = G' m.

The acceleration of the orbiting mass is given by
a = F/m = G' m/m = G'.

As you can see, the orbiting object's motion isn't governed by its mass.

 

[Lighthouse]

I take it that the sum of the substance you are going to offer is "I don't believe it"?

I certainly don't buy it. And not just because there's no proof. But anyone with an ounce of common sense can see how ridiculous the idea that time passes at different rates for different people, based on perspective is trash. The only thing that's relative is perception. Time doesn't change.

 

[dan1el]

I certainly don't buy it. And not just because there's no proof. But anyone with an ounce of common sense can see how ridiculous the idea that time passes at different rates for different people, based on perspective is trash. The only thing that's relative is perception. Time doesn't change.

Where do you get the ridiculous idea that common sense should be trusted when examining how the universe works?