about Bob's article on absolute or relative time

[fool]

If they are standing still, yes.

What if they're on treadmills?

No really So the guy at the top and the guy at the bottom have stared at each other thru telescopes across a distance that didn't change but they traveled differnt distances, just like in a race a guy who was on the outside comes to the finish line and and a guy who was next to him on the inside the whole time have different milages on their odometers for that race and then they shake hands?
Yes?
No?

 

[Lighthouse]

What if they're on treadmills?

No really So the guy at the top and the guy at the bottom have stared at each other thru telescopes across a distance that didn't change but they traveled differnt distances, just like in a race a guy who was on the outside comes to the finish line and and a guy who was next to him on the inside the whole time have different milages on their odometers for that race and then they shake hands?
Yes?
No?

I didn't understand what you meant at first.

But the bottom line is that the top of a mountain travels faster through space than the core of the Earth, in the Earth's rotation. Because the top of the mountain must travel further, and yet must keep up.

None of this changes the rate at which time passes.

 

[Stripe]

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.

I'm not sure your example is equivalent to changing the moon into an apple.

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

Why is this assumption necessary. We have two clocks that respond differently according to the gravitational forces acting upon them. Why do we need time distortions to explain the differences? Why not just say that gravity affected the clocks?

 

[dan1el]

:bang:

No answer?

I'm not sure your example is equivalent to changing the moon into an apple.

http://www.theologyonline.com/forums/showpost.php?p=2039893&postcount=58

 

[Stripe]

http://www.theologyonline.com/forums/showpost.php?p=2039893&postcount=58

My understanding of the physics involved is not as trained as the others, but my impression is that the Earth-Moon system is a dynamic one. That is the Moon is falling toward the Earth and the Earth is also falling toward the Moon. If the Moon were to turn into an apple and retain its velocity then the equations you posted would all skew toward the Earth. Thus the Earth would not fall toward the moon any more and the Moon's orbit would not remain as it is.

That sounds a fairly reasonable assumption to me, but I don't have the equations to back it up.

 

[ThePhy]

My understanding of the physics involved is not as trained as the others, but my impression is that the Earth-Moon system is a dynamic one. That is the Moon is falling toward the Earth and the Earth is also falling toward the Moon. If the Moon were to turn into an apple and retain its velocity then the equations you posted would all skew toward the Earth. Thus the Earth would not fall toward the moon any more and the Moon's orbit would not remain as it is. …

Technically you are correct. Though we casually speak of the moon orbiting the earth, in fact both the moon and the earth orbit around their common center of mass. With the moon being a significant sized body, that common center of mass is not at the center of the earth, but some distance towards the moon on the line from the earth’s center to the lunar center.

But replacing the moon with an apple would just mean the common center of mass of the “earth-apple” system would be a billionth of an inch displaced from the earth’s center, instead of kilometers as it is now. In common parlance (and in scientific literature) the apple would still be orbiting the earth, and at the same distance and speed as the original moon did.

 

[Lighthouse]

No answer?

It was so ignorant it didn't deserve an answer.

 

[dan1el]

It was so ignorant it didn't deserve an answer.

That's quite ironic coming from you.

 

[fool]

I didn't understand what you meant at first.

That's OK we'll get there.

But the bottom line is that the top of a mountain travels faster through space than the core of the Earth, in the Earth's rotation. Because the top of the mountain must travel further, and yet must keep up.

Good, so the guy at the top of the mountain is goig faster than the guy at the bottom. His miles traveled per day is greater than the guy at the bottom and his miles per hour are greater right?

None of this changes the rate at which time passes.

We haven't got to that yet.

 

[Lighthouse]

That's OK we'll get there.


Good, so the guy at the top of the mountain is goig faster than the guy at the bottom. His miles traveled per day is greater than the guy at the bottom and his miles per hour are greater right?

He is going faster, yes. And his miles traveled are greater. What of it?

 

[Stripe]

Technically you are correct. Though we casually speak of the moon orbiting the earth, in fact both the moon and the earth orbit around their common center of mass. With the moon being a significant sized body, that common center of mass is not at the center of the earth, but some distance towards the moon on the line from the earth’s center to the lunar center.

But replacing the moon with an apple would just mean the common center of mass of the “earth-apple” system would be a billionth of an inch displaced from the earth’s center, instead of kilometers as it is now. In common parlance (and in scientific literature) the apple would still be orbiting the earth, and at the same distance and speed as the original moon did.

If the Earth is no longer being pulled toward the Moon then its orbit around the moon will change.

You said the tides would cease, how is that any different from an orbit ceasing?

 

[Stripe]

I went here and it seems changing the mass of a planet will affect the orbit. :idunno:

 

[ThePhy]

If the Earth is no longer being pulled toward the Moon then its orbit around the moon will change.

You said the tides would cease, how is that any different from an orbit ceasing?

The tides would cease because the apple in the moon’s orbit exerts such a miniscule gravitational attraction back on the earth (Newton’s 3rd law - action-reaction) that it is effectively undetectable. (Technically, a high apple tide might be a hundred thousandth of a human hair thickness in height.)

 

[Gerald]

Let me get this straight: there are folks on this thread claiming that time dilation doesn't occur? :doh:

 

[fool]

He is going faster, yes. And his miles traveled are greater. What of it?

And when he come back down the mountain and shakes hands with the guy at the bottom nothing strange happens right?

 

[Stripe]

The tides would cease because the apple in the moon’s orbit exerts such a miniscule gravitational attraction back on the earth (Newton’s 3rd law - action-reaction) that it is effectively undetectable. (Technically, a high apple tide might be a hundred thousandth of a human hair thickness in height.)

How is the cessation of the tides any different from the cessation of an orbit?

 

[Lon]

The idea of clocks being affected by time has nothing to do with time, but the gravitational pull on the clock mechanism for keeping time, if I remember the discussion.

I don't have a problem with that if it can be shown that electronics are affected by gravity. We'd have to have some way of measuring time that is not mechanically affected by gravity, but maintains proper sequence measurement.

The subject matter delves into whether God experiences progressive duration alone, as we do (denies foreknowledge etc.)

 

[Stripe]

We'd have to have some way of measuring time that is not mechanically affected by gravity, but maintains proper sequence measurement.

The problem is you're trying to measure something that does not exist. Time is not a physical thing that can be measured. It's an abstract concept that we use to make sense of the world. Our measurement of it will only ever be as accurate as the tools we can make.

 

[Lighthouse]

And when he come back down the mountain and shakes hands with the guy at the bottom nothing strange happens right?

And you think that means time itself is relative?

 

[Lon]

The problem is you're trying to measure something that does not exist. Time is not a physical thing that can be measured. It's an abstract concept that we use to make sense of the world. Our measurement of it will only ever be as accurate as the tools we can make.

I agree with you here, but I think some are missing the point of inquiry: gravity affects mechanical clocks and that was the only premise I was addressing. In order to test that theory and rule out the possibility of time progressing differently, we'd have to make a mechanical clock that is unaffected by gravity. Even in that, we'd not rule out differing durations, we'd just rule out that a clock measured it.

Hope that makes sense. Time is a complicated issue.

Ever play with time and the international dateline with a pen and piece of scratch paper?