Target Distance and Light Travel: The Impact on Spatial Position

[russ_watters]

Are objects in the universe in some kind of motion?

With respect to some objects, yes, with respect to other objects, no.

 

[cfrogue]

With respect to some objects, yes, with respect to other objects, no.

OK, I see. You are saying there is only relative motion.

But, light always emits at c correct?

 

[russ_watters]

Both correct.

 

[cfrogue]

Both correct.

So, when you are in a stationary frame, is that frame at absolute rest?

 

[russ_watters]

So, when you are in a stationary frame, is that frame at absolute rest?

You are always stationary with respect to yourself and there is no such thing as absolute rest.

 

[cfrogue]

You are always stationary with respect to yourself and there is no such thing as absolute rest.

OK, so you are stationary in a frame and there is no such thing as absolute rest.

Thus, the frame has some kind of motion, but it is not known.


Is this correct?

 

[Dale]

Thus, the frame has some kind of motion, but it is not known.

Why wouldn't it be known? The motion of any given inertial frame wrt any other given inertial frame is well-defined.

 

[russ_watters]

OK, so you are stationary in a frame and there is no such thing as absolute rest.

You are stationary with respect to your frame of reference, yes.

Thus, the frame has some kind of motion, but it is not known.


Is this correct?

That's very oddly worded. As I said above:

...since any object can and does have an infinite number of different speeds at the same time.

So an object has an infinite number of different speeds, depending on what you are measuring its speed with respect to. But I don't know why you would say it isn't known. Lots of them can be known.

 

[cfrogue]

You are stationary with respect to your frame of reference, yes. That's very oddly worded. As I said above: So an object has an infinite number of different speeds, depending on what you are measuring its speed with respect to. But I don't know why you would say it isn't known. Lots of them can be known.

Well, a frame is at absolute rest or is moving.

You said absolute rest does not exists. So, I guess a frame moves.

What if no other frame exists locally and you are not able to determine relative motion.

Does this mean the frame is at absolute rest or is it moving in some unknown way?

 

[russ_watters]

Well, a frame is at absolute rest or is moving.

You said absolute rest does not exists. So, I guess a frame moves.

What if no other frame exists locally and you are not able to determine relative motion.

Does this mean the frame is at absolute rest or is it moving in some unknown way?

You seem to be implying that if a frame is not at absolute rest, it has an absolute motion. That's not correct. It has been said many times in this thread, in different ways:

All motion (or lack thereof) is relative. It is measured between two objects/frames of reference.

If you have no other frame of reference to measure an object's speed against, then you can say nothing about its speed.

I'm not sure why we are having so much trouble explaining this to you, but you may want to read the wiki on the concept of motion: http://en.wikipedia.org/wiki/Motion_(physics )

 

[cfrogue]

You seem to be implying that if a frame is not at absolute rest, it has an absolute motion. That's not correct. It has been said many times in this thread, in different ways:

All motion (or lack thereof) is relative. It is measured between two objects/frames of reference.

If you have no other frame of reference to measure an object's speed against, then you can say nothing about its speed.

So, if a frame is in the universe and the nearest object is billions of light years away, you have no frame of reference in an reasonable time reference, is the frame moving somehow or is it at absolute rest?

Certainly, you would have no idea at all since there is no mechanical way to detect absolute motion, but does that lack of ability to detect it imply it does not exist?

 

[russ_watters]

So, if a frame is in the universe and the nearest object is billions of light years away, you have no frame of reference in an reasonable time reference, is the frame moving somehow or is it at absolute rest?

Whether it is easy or difficult to measure the speed of an object with respect to another doesn't really have any bearing on how the laws of physics work. I'm not sure how many times you need to see this in order for it to sink in: there is no such thing as absolute rest.

Perhaps the problem is you simply choose not to believe that this is how the universe works? That's what this implies:

Certainly, you would have no idea at all since there is no mechanical way to detect absolute motion, but does that lack of ability to detect it imply it does not exist?

No, it is what we can detect that implies absolute motion/rest does not exist.

Again, think of the table tennis on a train example. Despite the fact that we can measure the ping pong table both stationary and moving, it has no impact on the play of the game.

 

[Dale]

Well, a frame is at absolute rest or is moving.

How do you conclude this?

 

[cfrogue]

How do you conclude this?

Simple, the Earth is moving somehow or not moving.

I am guessing it is moving. How about you?

 

[cfrogue]

Whether it is easy or difficult to measure the speed of an object with respect to another doesn't really have any bearing on how the laws of physics work. I'm not sure how many times you need to see this in order for it to sink in: there is no such thing as absolute rest.

Perhaps the problem is you simply choose not to believe that this is how the universe works? That's what this implies: No, it is what we can detect that implies absolute motion/rest does not exist.
Again, think of the table tennis on a train example. Despite the fact that we can measure the ping pong table both stationary and moving, it has no impact on the play of the game.

Absolute motion is not detectable. That is a fact or we would not be having this conversation.

How do you prove that means it does not exist? How do you prove an object has no motion unless there is another to compare it to?

May I see this proof?

 

[russ_watters]

Simple, the Earth is moving somehow or not moving.

I am guessing it is moving. How about you?

From where I'm sitting right now the Earth is not moving. Of course, when I drove home from work yesterday, it was moving. Do you understand that? "Moving" and "not moving" actually aren't fundamentally different from each other. 0 and 60 are both just numbers. Right now, sitting on my couch, the Earth has a speed of 0. But when driving home from work, it was 60.

 

[russ_watters]

Absolute motion is not detectable. That is a fact or we would not be having this conversation.

How do you prove that means it does not exist?

How do you prove an object has no motion unless there is another to compare it to?

May I see this proof?

You could respond to the examples given already that explain why if it did exist, we could detect it. Ignoring the proof doesn't make it go away.

[there is also a sticky on that very request at the top of the SR forum page]

 

[cfrogue]

You could respond to the examples given already that explain why if it did exist, we could detect it. Ignoring the proof doesn't make it go away.

What?

Are you claiming it is impossible to detect?

How do you prove this?

Can I see the proof?

Otherwise, you have no choice but to assume a frame moves around in some unknown way.
This is simple logic.

 

[cfrogue]

From where I'm sitting right now the Earth is not moving. Of course, when I drove home from work yesterday, it was moving. Do you understand that? "Moving" and "not moving" actually aren't fundamentally different from each other. 0 and 60 are both just numbers. Right now, sitting on my couch, the Earth has a speed of 0. But when driving home from work, it was 60.

I have the relative motion thing figured out.

While you drove home, you were at rest and the Earth was moving relative to you.

When Apollo went to the moon, the spaceship did not move, the Earth did.

Yes, I have this figured out.

 

[Dale]

Simple, the Earth is moving somehow or not moving.

I am guessing it is moving. How about you?

You are guessing that it is moving relative to what?

 

[russ_watters]

What?

Are you claiming it is impossible to detect?

No, you are claiming that it exists, but is impossible to detect. *I* (Ie, the laws of physics) claim that it doesn't exist and experiments prove it.

How do you prove this?

Can I see the proof?

Examples, and where to find more, have been given. If you have specific questions about specific ones, ask. But you need to put some effort into this yourself.

Otherwise, you have no choice but to assume a frame moves around in some unknown way.
This is simple logic.

That's not logic, it's gibberish.

Lets try some logic, though: if you don't believe that something can be shown to exist (absolute motion/rest), why do you still believe it does? Isn't that illogical?

I have the relative motion thing figured out.

While you drove home, you were at rest and the Earth was moving relative to you.

When Apollo went to the moon, the spaceship did not move, the Earth did.

Yes, I have this figured out.

Clearly you don't or you wouldn't have asked the questions above.

 

[cfrogue]

You are guessing that it is moving relative to what?

Well, the Earth is moving relative to the sun which is moving relative to the milky way.

So, if I shot a laser at a target on the earth, would I hit it perfectly?

 

[russ_watters]

Well, the Earth is moving relative to the sun which is moving relative to the milky way.

Ok...

So, if I shot a laser at a target on the earth, would I hit it perfectly?

If you have good aim, sure.

 

[cfrogue]

No, you are claiming that it exists, but is impossible to detect. *I* (Ie, the laws of physics) claim that it doesn't exist and experiments prove it. Examples, and where to find more, have been given. If you have specific questions about specific ones, ask. But you need to put some effort into this yourself.

That's not logic, it's gibberish.

Lets try some logic, though: if you don't believe that something can be shown to exist (absolute motion/rest), why do you still believe it does? Isn't that illogical?
Clearly you don't or you wouldn't have asked the questions above.

*I* (Ie, the laws of physics) claim that it doesn't exist and experiments prove it.

How do you prove something does not exist?

May I see the proof?

 

[cfrogue]

Ok... If you have good aim, sure.

Well, you line up the target, the Earth is moving with a rotation and then in its orbit around the sun.

Then the milky way moves.

How do you know where the target will be when the light reaches it?

Are you assuming the target is at absolute rest?

 

[russ_watters]

*I* (Ie, the laws of physics) claim that it doesn't exist and experiments prove it.

How do you prove something does not exist?

May I see the proof?

Yes, please do. Stop asking and look at what has been provided for you. It isn't like I'm going to type a 10,000 word essay on Relativity into the forum.

 

[russ_watters]

Well, you line up the target, the Earth is moving with a rotation and then in its orbit around the sun.

Then the milky way moves.

How do you know where the target will be when the light reaches it?

Are you assuming the target is at absolute rest?

No, I'm a skilled shot and understand the concept of pulling lead on a moving target.

 

[cfrogue]

Yes, please do. Stop asking and look at what has been provided for you. It isn't like I'm going to type a 10,000 word essay on Relativity into the forum.

No, I know what a math proof is and you have not provided it.

 

[russ_watters]

...better yet, since your belief is that if a universal reference frame existed it would be undetectable (ie, have no bearing on our observations/experiments), ask yourself why this conversation even matters. In terms of the way the laws of physics work, there is no difference between "undetectable" and "doesn't exist". So why bother even arguing about it?

 

[cfrogue]

No, I'm a skilled shot and understand the concept of pulling lead on a moving target.

LOL, good one.

 

[russ_watters]

No, I know what a math proof is and you have not provided it.

Math proof of what? I don't think even you know what you are asking!

 

[russ_watters]

LOL, good one.

That wasn't a joke. Perhaps this is a game to you, but it isn't to us.

 

[russ_watters]

We're done here. It has come down to you simply wanting to believe something for which you accept there is no evidence, which is just plain irrational. I'm not sure it is possible for us to help you get past that, but if you really want to, you're going to have to put some effort into it. As I said before, there is a sticky on the top of the forum about the experimental basis of Relativity. In it, there is a link to a list of experiments. Read the link and come back with specific questions about specific things you don't understand. But we're not going to keep playing this game of yours.