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Mark1980
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Hello I have been trying to understand the twin paradox (without math) but I’m still trying to grasp the idea. I have seen and read enough tutorials to know that acceleration is not needed for the twin paradox to be solved. For anyone who doesn’t know the twin paradox without acceleration thought experiment it goes like this.
An outbound traveller from beyond Earth is moving at a constant velocity 0.5c relative to Earth towards a distant star which is also on the same inertial frame as the earth. As they pass the earth, the Earth observer and the outbound traveller start a clock at zero. At the same time there is an inbound traveller beyond the distant star traveling at the same constant velocity as the outbound traveller but in the opposite direction. Both travellers will pass the distant star at the same time at which point the inbound traveller will synchronise a clock with the time of the outbound traveller. Later on when the inbound traveller passes by the Earth and compares their clock with the earth, their clock will read less time than the Earth's. This is explained by the fact that the travellers clocks had been on two inertial frames.
I am struggling with this idea a little so let me propose a similar thought experiment below to further illustrate my thinking.
Suppose you have three planets lined up an equal distance apart on the same inertial frame, let’s call them Planet A, B & C. Now let’s say there are two spaceships, let’s call them spaceship X and spaceship Y. X is traveling at a constant velocity v (0.5c relative to the planets) from beyond A towards C via B. Y is traveling at the same constant velocity but in the opposite direction. X will pass by A at the same time as Y passes by C.
Now suppose as X and Y pass A and C respectively they will both start a clock to time their journeys. An observer on planet A will also start a clock at this time. When the spaceships reach B (and pass each other by) Y will synchronise a second clock with the clock from X.
Now we have three clocks, one on planet A and two on Spaceship Y; his own original clock started at intersection of planet C and the one he synchronised with X’s clock at the intersection of planet B.
As Y passes by A they will compare all the clocks times. According to the thought experiments I have read on the twin paradox, the clock that was synchronised from Spaceship X should read less than the clock on Planet A (for arguments sake let’s say 20 years). Planet A should read more (for arguments sake let’s say 30 years) than this and therefore the traveling clock has aged less.
However my confusion is coming from the fact that Y’s original clock would also read 20 years would it not? 10 years from planet C to B and another 10 years from B to A. But this clock is only on one inertial frame so why would their original clock have read 20 years whilst the planet A’s clock reads 30 as both can be considered at rest?
Apologies if this thought experiment is too confusing I tried to make it as simple as possible. I’m certain my thinking is wrong somewhere here but if someone can point out to me where I am going wrong it would be appreciated.
An outbound traveller from beyond Earth is moving at a constant velocity 0.5c relative to Earth towards a distant star which is also on the same inertial frame as the earth. As they pass the earth, the Earth observer and the outbound traveller start a clock at zero. At the same time there is an inbound traveller beyond the distant star traveling at the same constant velocity as the outbound traveller but in the opposite direction. Both travellers will pass the distant star at the same time at which point the inbound traveller will synchronise a clock with the time of the outbound traveller. Later on when the inbound traveller passes by the Earth and compares their clock with the earth, their clock will read less time than the Earth's. This is explained by the fact that the travellers clocks had been on two inertial frames.
I am struggling with this idea a little so let me propose a similar thought experiment below to further illustrate my thinking.
Suppose you have three planets lined up an equal distance apart on the same inertial frame, let’s call them Planet A, B & C. Now let’s say there are two spaceships, let’s call them spaceship X and spaceship Y. X is traveling at a constant velocity v (0.5c relative to the planets) from beyond A towards C via B. Y is traveling at the same constant velocity but in the opposite direction. X will pass by A at the same time as Y passes by C.
Now suppose as X and Y pass A and C respectively they will both start a clock to time their journeys. An observer on planet A will also start a clock at this time. When the spaceships reach B (and pass each other by) Y will synchronise a second clock with the clock from X.
Now we have three clocks, one on planet A and two on Spaceship Y; his own original clock started at intersection of planet C and the one he synchronised with X’s clock at the intersection of planet B.
As Y passes by A they will compare all the clocks times. According to the thought experiments I have read on the twin paradox, the clock that was synchronised from Spaceship X should read less than the clock on Planet A (for arguments sake let’s say 20 years). Planet A should read more (for arguments sake let’s say 30 years) than this and therefore the traveling clock has aged less.
However my confusion is coming from the fact that Y’s original clock would also read 20 years would it not? 10 years from planet C to B and another 10 years from B to A. But this clock is only on one inertial frame so why would their original clock have read 20 years whilst the planet A’s clock reads 30 as both can be considered at rest?
Apologies if this thought experiment is too confusing I tried to make it as simple as possible. I’m certain my thinking is wrong somewhere here but if someone can point out to me where I am going wrong it would be appreciated.
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