Gravity slows down time.

chinglu said:
The traveling twin considered the earth's position along the journey.

That twin concluded 12 earth years elapsed for the journey.

Yet, that twin's clock claimed 10 years.

Now, what do we do with this?
The 12 earth years observed by the traveling twin (assuming they can observe the earth and count how many times it orbits the sun, but that isn't a requirement), takes 10 years of local time for that twin. However, this condition expires when both twins are again in the same frame of rest.

That's what "we do". And there is no need for the moving twin to be able to directly measure changes in the earth's position, they just need to leave a clock behind with their twin.

This thread is avoiding the issue.

The traveling twin considered the earth's position along the journey.

That twin concluded 12 earth years elapsed for the journey.

Yet, that twin's clock claimed 10 years.

Now, what do we do with this?

No you are avoiding the issue...Watch the video in my previous post...you maybe surprised.
But anyway, in your scenario, the travelling twin has aged 10 years, in line with his own on board systems clock and his own biological clock, and will find on his return to Earth, that his stay at home twin has aged 12 years by all Earth's clocks both mechanical and biological.

Now if you are fair dinkum with the argument that you continue to put, and not just playing silly buggers, you will check out the video I supplied.
Otherwise it is proof positive that you are playing with yourself and having a lend of the forum.

Check out the Video.

Well, did the traveler twin live 12 years or 10?

That is the question you did not answer.
The traveling twin aged 10 years.

This thread is avoiding the issue.

The traveling twin considered the earth's position along the journey.

That twin concluded 12 earth years elapsed for the journey.

Yet, that twin's clock claimed 10 years.

Now, what do we do with this?

Simple, we confirm you have no idea what you're talking about after repeated explanations. End of story.

The 12 earth years observed by the traveling twin (assuming they can observe the earth and count how many times it orbits the sun, but that isn't a requirement), takes 10 years of local time for that twin. However, this condition expires when both twins are again in the same frame of rest.

That's what "we do". And there is no need for the moving twin to be able to directly measure changes in the earth's position, they just need to leave a clock behind with their twin.

You have no logic here that works.

The traveling twin observed 12 earth years. The stay at home twin has 12 earth years on its clock.

However, the traveling twin's clock shows 10 years when reunited with the earth twin.

So, does the traveling twin eject the scientific observations of 12 years or does that twin accept what is on his/her clock?

This is the issue.

No you are avoiding the issue...Watch the video in my previous post...you maybe surprised.
But anyway, in your scenario, the travelling twin has aged 10 years, in line with his own on board systems clock and his own biological clock, and will find on his return to Earth, that his stay at home twin has aged 12 years by all Earth's clocks both mechanical and biological.

Now if you are fair dinkum with the argument that you continue to put, and not just playing silly buggers, you will check out the video I supplied.
Otherwise it is proof positive that you are playing with yourself and having a lend of the forum.

Check out the Video.

You left off an important fact.

The traveling twin observed through careful scientific experiment and observation that he/she witnessed the earth orbiting around the sun 12 times during the journey.

So, on the return the only thing that disagrees with the science of 12 years is the traveling twin's clock.

Therefore, the traveling twin's clock must be wrong.

The traveling twin aged 10 years.

You also left off the fact that the traveling twin witnessed 12 earth orbits using science.

So is science false?

Goes this mean we cannot depend on any scientific observations on the universe.

Simple, we confirm you have no idea what you're talking about after repeated explanations. End of story.

12 earth orbits were witnessed by the traveling twin. What about that?

chinglu said:
The traveling twin observed 12 earth years. The stay at home twin has 12 earth years on its clock.

However, the traveling twin's clock shows 10 years when reunited with the earth twin.

So, does the traveling twin eject the scientific observations of 12 years or does that twin accept what is on his/her clock?
No, the twin accepts that the elapsed time for their journey was less than the elapsed time on the earth because of relativistic effects. The effect is called time dilation, but really that's only a convenient label. It's convenient because everyone "understands" time, even if they don't understand relative time, or frame-dependent time, etc.

No, the twin accepts that the elapsed time for their journey was less than the elapsed time on the earth because of relativistic effects. The effect is called time dilation, but really that's only a convenient label. It's convenient because everyone "understands" time, even if they don't understand relative time, or frame-dependent time, etc.

Wait now.

The traveling twin witnessed the earth traveling around the sun 12 times same as the earth twin.

You keep leaving this out. Now, what should this traveling twin do with the scientific evidence that proves he ages 12 years based on astronomical observations?

Should all astronomical observations be considered as false?

12 earth orbits were witnessed by the traveling twin. What about that?

That has been explained to ad nauseum.

That has been explained to ad nauseum.

No it has not.

Explain how the traveling twin's astronomical observations disagree with his clock.

Is he 12 years according to scientific observations or 10 years according to a theory?

You left off an important fact.

The traveling twin observed through careful scientific experiment and observation that he/she witnessed the earth orbiting around the sun 12 times during the journey.

So, on the return the only thing that disagrees with the science of 12 years is the traveling twin's clock.

Therefore, the traveling twin's clock must be wrong.

WRONG!!!!!

The travelling twin, through careful scientific experiment and observations, sees the stay at home twin age 12 years and the Earth orbiting the Sun 12 times......
BUT THE TRAVELLING TWIN IS IN ANOTHER FoR WHERE HE AGES ONLY 10 YEARS: HE LOGICALLY THEN CONCLUDES THAT TIME DILATION [AND LENGTH CONTRACTION] HAS TAKEN PLACE WITH REGARDS TO THE OTHER FoR

Have you checked out the video yet?
Or is the truth too hard to bear?

No you are avoiding the issue...Watch the video in my previous post...you maybe surprised.
But anyway, in your scenario, the travelling twin has aged 10 years, in line with his own on board systems clock and his own biological clock, and will find on his return to Earth, that his stay at home twin has aged 12 years by all Earth's clocks both mechanical and biological.

Now if you are fair dinkum with the argument that you continue to put, and not just playing silly buggers, you will check out the video I supplied.
Otherwise it is proof positive that you are playing with yourself and having a lend of the forum.

Check out the Video.

Are you saying this in your very best Aussie accent?

chinglu said:
The traveling twin witnessed the earth traveling around the sun 12 times same as the earth twin.

You keep leaving this out. Now, what should this traveling twin do with the scientific evidence that proves he ages 12 years based on astronomical observations?
The travelling twin indeed sees the earth orbit the sun 12 times, but for them it happens in 10 years of their time. There is no contradiction because, in spite of their observations, they don't age 12 years, but their twin does.

You still don't seem to have grasped the fact that the twins are in different time-frames.

The traveling twin witnessed the earth traveling around the sun 12 times same as the earth twin.
Now, what should this traveling twin do with the scientific evidence that proves he ages 12 years based on astronomical observations?
Yes, I see what you are trying to say, Chinglu. But you are forgetting that the traveling twin 'measures' each Earth orbit 'year' at 10/12th the 'value' in his now-slowed clock measuring device accumulating a 'year's worth of seconds which in total is 10/12th the total of the stay-put twins clock seconds count for that same orbit.

So, yes, the traveling twin measures the Earth going around 12 times too, but in his own traveling state the aging of that year in biological and clock process/count amounts to a 'year' being 10/12ths 'process time' as the stay-put 12/12 process time 'year'.

In other words, HIS 'aging value' for EACH 'year' of those 12 years is shorter for each Earth-sun orbit cycle than the stay-put twin's value for each year. The two 'values' are NOT the same even though the number of orbits is the same number for both.

When they re-unite this will become obvious as the 'aging value of 12 orbits' is LESS for the traveling twin. The two orbit counts were the same in absolute NUMBER/CYCLES, but NOT the same 'aging value' for each of the 'orbit units' counted.

Good luck!

Therefore it is impossible for two clocks to be at the same place and disagree on where the place is (located, relative to some other reference point).
I should add that this is only true if the two clocks are at rest relative to each other (comoving). If instead the two clocks have different worldlines and are at the "same place" momentarily, then they can disagree on where that place is located, relative, of course, to some other reference.

Yes, I see what you are trying to say, Chinglu. But you are forgetting that the traveling twin 'measures' each Earth orbit 'year' at 10/12th the 'value' in his now-slowed clock measuring device accumulating a 'year's worth of seconds which in total is 10/12th the total of the stay-put twins clock seconds count for that same orbit.

So, yes, the traveling twin measures the Earth going around 12 times too, but in his own traveling state the aging of that year in biological and clock process/count amounts to a 'year' being 10/12ths 'process time' as the stay-put 12/12 process time 'year'.

In other words, HIS 'aging value' for EACH 'year' of those 12 years is shorter for each Earth-sun orbit cycle than the stay-put twin's value for each year. The two 'values' are NOT the same even though the number of orbits is the same number for both.

When they re-unite this will become obvious as the 'aging value of 12 orbits' is LESS for the traveling twin. The two orbit counts were the same in absolute NUMBER/CYCLES, but NOT the same 'aging value' for each of the 'orbit units' counted.

Good luck!

G'day cobber

Great explanation - in that I understood clearly what you are saying .. often not the case with these things.

I don't want to preempt chinglus reply, and I would be very interested to see it, but meanwhile, I have a question - what defines the 'travelling' twin ?

Let's remove then from earth and spaceship and put then on two similar asteroids. Same 'travelling' scenario as above.

When they meet up again, it could be deduced from the above that they are both younger than each other. How does that work out ?

And please, make your explanation no more complex than the above if you could.

I wasn't able to follow what you posted
What Im trying to say is that, it takes 1 second for an atomic clock at sea level to measure 1 second. A dilated clock takes a faster or slower time to measure 1 second, depending on the time dilation the clock is experiencing. The problem I see is from the clocks frame of reference, the detectors time should also be dilated and the clock must be synchronized with all the other clocks experiencing TD for time dilation to exist.

We are saying the atomic clocks frequency is experiencing time dilation, but the atomic clocks detector isn't.

For some silly reason Im seeing TD the opposite way around. For TD to physically exist all the clocks should be automatically synchronized. For TD to not physically exist all the clocks shouldnt synchronize.

Im confused and its probably from something Im not understanding...

G'day cobber

Great explanation - in that I understood clearly what you are saying .. often not the case with these things.

I don't want to preempt chinglus reply, and I would be very interested to see it, but meanwhile, I have a question - what defines the 'travelling' twin ?

Let's remove then from earth and spaceship and put then on two similar asteroids. Same 'travelling' scenario as above.

When they meet up again, it could be deduced from the above that they are both younger than each other. How does that work out ?

And please, make your explanation no more complex than the above if you could.

Just re-reading my post, should make it clearer.

I'm talking about .. relative motion, I think it's called. Who's to say which twin is travelling and which one isn't ? And why should one have priority position at being at rest .. that sort of thing - you guys probably know more about what I'm talking than I do.