# A distinction to be made in Einstein's Relativity

## Recommended Posts

when the station comes to the train.

It must be explained that the station is not moving through

any space-time to get closer to the train. It is the train alone

that accelerates(experiences weight).

Therefore relative motion exists only in potential to

the absolute movement in space-time of something else.

This means that there is no reciprocity of effect in SR.

Only the object that accelerates in space-time will

experience length and time contraction.

An object flying by the earth at very near light velocity

will not have to wait to see Earth clocks. And they all

will be blueshifted. There is no reciprocity there.

Why should there be?

##### Share on other sites

Sorry, but you are mistaken. This is easily demonstrated every day with particle accelerators. The Earth itself accelerates as it orbits the Sun, thus the Earth's orbital velocity of 30km/sec would be added and substracted to the particle's final velocity as it leaves the accelerator during different points of its orbit. Today's accelerators can reach velocities close enough to c that this 60 km/sec variation would cause a noticeable difference in relativistic effects seen in those particles over the course of a year. No such variations are ever noticed.

##### Share on other sites

Oh really?

Particle accelerators prove that the Earth is moving near the

speed of light through space because those particles accelerated?

You're a kook and BTW GR only explains curvilinear motion.

Curved space-time only explains changes in direction.

Can you see that?

Otherwise can you explain to me how gravity accelerates?

We know how it changes directions - curvature - but how

does it change speed?

##### Share on other sites

Oh really?

Particle accelerators prove that the Earth is moving near the

speed of light through space because those particles accelerated?

That's not what he said. You can't measure the speed at which anything "moves through space" since there is no absolute rest frame. You have to pick something in space as a reference point. The fact that motion of the earth with respect to the sun does not get superimposed on accelerator results demonstrates that motion is not absolute, as does any number of Michelson-Morley results, and many more lab results that rely on relativity being correct.

##### Share on other sites

Boloney. We can't measure how fast the Earth orbits/moves

through space around the sun?

We can measure it moving through space.

The reason there is no absolute rest is because everything

in the universe is moving through space. That what no absolute

rest actually means.

Measuring motion through space is a sinch.

##### Share on other sites

no, not another "relativity is wrong because it is counterintuitive to me" person.

##### Share on other sites

He just said we can't measure motion through space.

Its easy to do!!! Or don't you like my example?

Everything has some kind of motion through space

and we can stand back and look at everything moving

as a whole within the universe and we see that motion

through space is absolute. There is no contradiction

in saying that something is moving through space

toward or away from something else.

How else do we calculate the movements of everything?

You can't make me out to be against Relativity.

There is something wrong with Relativity. But I don't

throw the baby out with the bathwater!!!

##### Share on other sites

You can't measure motion through 'space' because what are you going to measure it against? You can only measure movement relative to something else. And whether that something else is also 'moving' is a frame dependent statement.

In your first post, if your train is moving towards the station at constant velocity, then it is not accelerating. Then, as Einstein pointed out, you may as well say that the station is moving towards the train.

##### Share on other sites

Boloney. We can't measure how fast the Earth orbits/moves

through space around the sun?

We can measure it moving through space.

...

Measuring motion through space is a sinch.

Explain how it is done, then.

##### Share on other sites

We can measure motion of matter through space relative to

other matter. This movement through space is an absolute.

Let us say a space ship takes off from mars heading toward

the Earth.The space ship accelerates toward the Earth.

You can't say that the Earth is moving through space

to get closer to the space ship. All you can say is that

the space ship is moving through space to get closer

to the Earth. Not the other way around.

##### Share on other sites

keyword is Accerate.

##### Share on other sites

We can measure motion of matter through space relative to

other matter. This movement through space is an absolute.

Let us say a space ship takes off from mars heading toward

the Earth.The space ship accelerates toward the Earth.

You can't say that the Earth is moving through space

to get closer to the space ship. All you can say is that

the space ship is moving through space to get closer

to the Earth. Not the other way around.

So you were mistaken before. The measurement is with respect to some other object, not space.

Absent any acceleration, how do you tell which object is moving?

##### Share on other sites

No it is both. It is the distance in space to the target object.

You can calculate your speed though space to get to it.

Moving through space is absolute. Without a reference you

couldn't measure it. And you and the reference might be moving

through space with respect to something else. But then

that is always measurable in practice.

If we were on a ship going to andromeda, lets say, we

can calculate our motion through space to get there.

Show me where I am wrong.

##### Share on other sites

hmm, moving through space is absolute....you and your buddy each have spaceships. you both feel no gravity. you pass each other. who was moving?

##### Share on other sites

As Einstein said: when the station comes to the train.

But only the train is moving through space to get closer

to the station.

Two space ships passing each other could both have

there individual motions through space. But if you use

the train example then its the train alone that passes

the station in space.

##### Share on other sites

No it is both. It is the distance in space to the target object.

You can calculate your speed though space to get to it.

Moving through space is absolute. Without a reference you

couldn't measure it. And you and the reference might be moving

through space with respect to something else. But then

that is always measurable in practice.

If we were on a ship going to andromeda' date=' lets say, we

can calculate our motion through space to get there.

Show me where I am wrong. [/quote']

If you can't measure it without some reference, it isn't absolute, and you aren't measuring motion with respect to space. As with yourdad's example - absolute motion means you could tell which one is moving.

##### Share on other sites

keyword is Accerate.

Lol! Have you been drinking?

We can measure motion of matter through space relative to other matter. This movement through space is an absolute.

Your first and second sentences have no link to one another. If movement through space were absolute you should be able to measure it. You still have not explained how to do it - all you have explained is how to measure velocity relative to another object.

##### Share on other sites

As Einstein said: when the station comes to the train.

But only the train is moving through space to get closer

to the station.

Two space ships passing each other could both have

there individual motions through space. But if you use

the train example then its the train alone that passes

the station in space.

So is the station in Brazil moving through space...or the one in China?

##### Share on other sites

Lol! Have you been drinking?
I'm not as think as you drunk I am.
##### Share on other sites

If you can't measure it without some reference, it isn't absolute, and you aren't measuring motion with respect to space. .

If that is true how come can succesfuly calculate/measure

the amount of space we have traveled through?

A speed through that distance is absolute.

##### Share on other sites

If that is true how come can succesfuly calculate/measure

the amount of space we have traveled through?

We can't. What we can do is choose some convenient reference point and calculate our relative motion with respect to it.
But that reference point is can only be consider "stationary" for convenience's sake we can know nothing about our absolute motion through space

A speed through that distance is absolute.

Since there is no absolute reference to judge that speed by, speed can never be absolute.

##### Share on other sites

If that is true how come can succesfuly calculate/measure

the amount of space we have traveled through?

A speed through that distance is absolute.

You measure with respect to some reference. Without a reference, you can't tell if anything is moving. Even with a reference, you can't say if you are moving or the reference is, only that you are moving relative to each other.

Stating that it's absolute means nothing. Devise an experiment that would measure speed of motion without some reference.

##### Share on other sites

Imagine this: You are in a space ship in space(obviously) you can detect motion in every single point of reference(stars, galaxies etc.) measured from your space ship they are all moving with a velocity x ms^-1. are you moving or is the rest of the universe moving? (disclaimer: i am ignoring expansion for the purposes of this thought experiment and this is here to see if nicholas actually reads the whole thing)

##### Share on other sites

more examples wont change his mind.

##### Share on other sites

You're probably right but my mind is open enough to give it a shot (now you can't accuse me of having a closed mind just like other pseudoscientists do )

## Create an account

Register a new account