Originally Posted by

**37818**
This experiment is a though and arithmetic experiment.

We do make sum assumptions.

One assumption we make to do this experiment we assume time is absolute.

Well, that is going to cause you some problems...

Now we have an observe A, traveler B and a destination C, one light year away.

Now the traveler B leaves observe A at 1/2 the speed of light. It will take 2 years fot the traveler to reach the destination.

You need to be careful whose frame of reference you are using. It will take 2 years

**according to the observer**.

The destination is year -1. at the time the traveler left.

Why isn't the time the same at the destination. You mentioned "absolute time"; wouldn't this imply it is the same time everywhere?

So from the observers point of view it will be 3 years before the observer sees the traveler arrived 1 light year away.

OK. It takes 2 years for the traveller to get there and 1 year for the light to return. That makes sense.

The observer sees the traveler's clock running slow at 2/3 speed.

No. The observer sees the traveller's clock running at 87% of his.

But if you are asserting absolute time, then surely he will see the other clock running at the same speed as his?

The traveler is going to arive in two years.

He will arrive in 2 years according to the observer. He will arrive in 1.7 years (I think) according to him.

And will see his observer at year 1 when the traveler arrives at year 2.

I'm pretty sure that is wrong, but I don't have time to work it out right now.

So the traveler sees the observer's clock slower at 1/2 speed.

No. The traveller sees the observer's clock running at 87% of his.

Shouldn't they see each other's clock rates slower at the same amount? One would think so.

They do. (Ignoring any acceleration at the start/end of the journey.)

The only way that can be possible to see both clocks appear to run at the same rate is if the traveler's time is to also be running slower according to relativity. And so this shows that time is not absolute and not the same every were.

Ah, I see. (I should have read the whole thing first!) But without relativity, they would see each others clocks running at the same speed. So, I'm not sure your argument works.