Seeing things in their past? You are full of beans!

[Polymath257]

If I was running a mile. Even if I could run at the speed of light. The distance I would run would still be 1 mile, regardless of how fast I ran. I admit it would seem like it took almost no time to run it, since I just blazed thru it. But it would have still been a mile.

But when you start getting the distances out there to 30 million light years, It would take me a little while to run that.

When you say that you ran a mile, you measured that mile in some reference frame.

So, suppose you measured out a mile on the Earth (in the reference frame at rest on the Earth).

Now, suppose you run this race at 86% of c with respect to the Earth. In the earth's reference frame, you would take 1 mile/.86c = .000006242 seconds. This is using the speed of light as 186282 miles per second.

Now, in *your* frame of reference, the earth is going past *you* at 86% of c. Are you OK with my saying this? if not, then we have to discuss this. If you are going past the Earth at 86% of c, then the Earth is going past you at 86% of c.

Now, the reason I use 86% of c so often is that the dilation factor is simple: it is .5.

So, in *your* frame, that mile on the Earth is only 1/2 a mile. This is the precise, accurate measurement. It is going past you at 86% of c, and so it takes .000003121 seconds for *you* to go from the start of the race to the end.

Next, when you say that star is 30 million light year away, you measure it in some reference frame, probably that of the Earth. If you are in a spaceship going at 86% of the speed of light, it would take you 30 million/.86 = 34.88 million years to get there *from the reference frame of the Earth*.

But, in *your* reference frame, that star is moving towards you at 86% of the speed of light. And in *your* reference frame, that star was originally not 30 million light years, but was 15 million light years away. So it only takes 15 million/.86 = 17.44 million years until the star reaches you.

Both the time of travel and the distance of travel depend on the specific frame used to measure them. No frame is more or less correct than any other frame.

 

[Polymath257]

If we truly have the correct number to use for C, then only one distance is actually correct. It would be the one we get when using the formula C=distance/time. Unless the concept of time doesn't mean anything to you.

This is a common intuition, BUT IT IS WRONG. Both the distance and the time of travel depend on the reference frame used to measure them. In all reference frames, dist/time = c. But the distance and times are different in different frames.

 

[Thermos aquaticus]

If I was running a mile. Even if I could run at the speed of light. The distance I would run would still be 1 mile, regardless of how fast I ran.

1 mile according to whom? Observers with different relative velocities will measure different distances between any two points. The higher your velocity the more length contraction there is. At the speed of light, length contraction becomes infinite and there are no distances.

 

[Thermos aquaticus]

A spaceship travelling at the speed of light was above the earth and fired a laser back , it took 4 minutes because the light was constant.

There is no time or distance at the speed of light.

 

[james blunt]

There is no time or distance at the speed of light.

Don't talk such absurdities. That would be completely illogical Mr Thermos and not demonstrated.

 

[Thermos aquaticus]

Don't talk such absurdities. That would be completely illogical Mr Thermos and not demonstrated.

This is proven physics.

 

[james blunt]

This is proven physics.

All happening within a constant frame dear chap, as in the background to your lines. Illusions are easy to create in physics.

 

[Thermos aquaticus]

All happening within a constant frame dear chap, as in the background to your lines. Illusions are easy to create in physics.

It isn't an illusion.

Hafele–Keating experiment - Wikipedia

 

[james blunt]

It isn't an illusion.

Hafele–Keating experiment - Wikipedia

You quite clearly do not understand what you are ''preaching'' do you ?

It is a timing dilation . NOT a time dilation.

The distance contraction is because the Earth spins Eastward towards a westerly travelling sun.

That is why the GPS has to be re-aligned.

Ok?

 

[Polymath257]

This is proven physics.

it should be pointed out that some care is required in using these formulas. In the time dilation formula, T_0 needs to be measured by a clock at rest in the relevant frame.

More relevantly, for the length formula, the length has to be of an object that exists over a long enough time interval. Both L and L_0 are measured simultaneously in the appropriate frame. This is important because the two endpoints at a particular time in one reference frame are two separate events and are at different times in the other reference frame. So, when L is measures, the endpoints correspond to different times than when L_0 is measured.

 

[Thermos aquaticus]

You quite clearly do not understand what you are ''preaching'' do you ?

I understand it just fine.

It is a timing dilation . NOT a time dilation.

It is time dilation.

Time dilation - Wikipedia

The distance contraction is because the Earth spins Eastward towards a westerly travelling sun.

That is why the GPS has to be re-aligned.

Ok?

Length contraction is due to relativity.

 

[Polymath257]

You quite clearly do not understand what you are ''preaching'' do you ?

It is a timing dilation . NOT a time dilation.

The distance contraction is because the Earth spins Eastward towards a westerly travelling sun.

That is why the GPS has to be re-aligned.

Ok?

That doesn't explain why we see time dilation effects between different stories of a building. NOT timing dilations, but time dilations.

 

[james blunt]

I understand it just fine.



It is time dilation.

Time dilation - Wikipedia



Length contraction is due to relativity.

yeah yeah, whatever, I have heard it a 1000 times if not more , it is a timing dilation Not a time dilation.

Which part of ''not'' , do you not understand?

 

[Polymath257]

yeah yeah, whatever, I have heard it a 1000 times if not more , it is a timing dilation Not a time dilation.

Which part of ''not'' , do you not understand?

I understand that you are NOT correct.

 

[james blunt]

That doesn't explain why we see time dilation effects between different stories of a building. NOT timing dilations, but time dilations.

Caesium timing dilation's.

 

[james blunt]

 

[james blunt]

OH ! They say .....

 

[Thermos aquaticus]

yeah yeah, whatever, I have heard it a 1000 times if not more , it is a timing dilation Not a time dilation.

The rest of the world calls it time dilation.

 

[james blunt]

The rest of the world calls it time dilation.

Misrepresented by the wrong wording causing confusion for the person learning the subject. You ever wondered why people disagree with you?

 

[Thermos aquaticus]

View attachment 22415

It is time itself that runs at a different speed as shown by every single experiment that has tested the idea. We can even see supernovae that move in slow motion for high red shift type Ia supernovae:

https://arxiv.org/pdf/0804.3595.pdf