Who Ages Faster in Relativistic Travel?

[phja]

i have read about the experiment of people ageing slower when moving at velocity and don't quite understand.

here's my experiment:

two people, person A and B, start off in the same referance frame (both are, say 20yrs old). person A flies off in one direction and person B in another. they accelerate to 99% c and stay like that for 5 years. from my understanding they would both see the other person age faster than themselves. now, after 5 years they turn around and come back to the same referance frame however they have seen the other person age faster than themselves. so my question is, who is older, or are they both the same age still. if we add person C who stayed in the initial referance frame and didn't accelerate, would A, B and C all be the same age or would C be older than A and B.

i suppose i may have missed some subtleties in how A and B observe each other when moving at 0.99c. is it possible that the amount of time it takes the light from A to reach B compansate for the slower ageing B would observe if the light traveled instantly.

PLEASE HELP!

 

[Fredrik]

Short answer: A and B are the same age. C is older.

Check out my standard explanation here, or do a search for "twin paradox" to see other people's explanations.

 

[Entropia]

Time dilation and aging are complex concepts in the field of physics that can be difficult to understand. The experiment you have described is a thought experiment commonly used to explain the concept of time dilation.

In this experiment, Person A and Person B start off in the same reference frame, meaning they are both at rest relative to each other. When they both start moving at 99% of the speed of light, they experience time dilation, which means that time appears to pass slower for them compared to someone who is at rest.

According to the theory of relativity, the faster an object moves, the slower time appears to pass for that object. In this case, Person A and Person B are moving at a very high speed, so time would appear to pass slower for them compared to someone who is at rest, such as Person C.

After 5 years, Person A and Person B turn around and come back to the same reference frame. At this point, they have experienced time dilation for a total of 10 years (5 years going out and 5 years coming back). So, according to their own experience, they would both be 10 years older.

However, from the perspective of Person C, who stayed in the initial reference frame, only 5 years have passed. This is because Person C did not experience time dilation and time passed normally for them.

So, to answer your question, all three people (A, B, and C) would technically be the same age, but their experiences of time would be different. This is because time is relative and depends on the observer's frame of reference.

To address your last question, the amount of time it takes for light to travel from Person A to Person B does not compensate for the slower aging that Person B would observe. Time dilation is a fundamental aspect of the theory of relativity and is not affected by the speed of light.

I hope this helps clarify your understanding of time dilation and aging. It is a complex concept, so don't worry if you still have questions. Keep exploring and learning about it, and eventually, it will start to make more sense.