- #1
AndyCiep
- 5
- 0
Hey everybody, this is my first post!
I've always had a problem understanding why, if a space-explorer left on a ship, traveled at nearly the speed of light for a while, and then came back to earth, he might have only aged a few months whereas the people of Earth would have aged many years.
Here's what I understand:
1. I understand that every frame of reference has it's own time. Thus, the ship has different time than the earth.
2. I also understand that at faster speeds, time slows down. Thus, on the ship, time will pass more slowly than it does on earth.
Now, due to (1) and (2) - it looks like I've already answered my own question. But here's what trips me up..
3. I also understand that every frame of reference is entitled to regard itself as being "at rest". For example, if two ships pass - both have the right to say they are sitting still and the other one is moving.
So, really - my problem is the following.. isn't it equally correct to say that the space-explorer (from the first paragraph) was sitting still in his spaceship, and that the Earth zoomed away from him, traveled at nearly the speed of light for a while, and then returned back to him?? And thus, shouldn't the earth's time have slowed? So then the people of Earth would have aged only a few months and the space-explorer would be the one who aged many years?
Seems to me that both cases are true. That the earthlings would see the space-explore's time slow relative to theirs, but that the space-explorer would see the Earth's time slow relative to his. So what happens when they meet up in the end and compare watches? Who's watch is ahead and who's is behind??
I'm very excited that I just happened to stumble across this website tonight. I've read a lot of the posts and know that there are a lot of very bright people out there answering questions. I'd love to have this one solved for me (it's been a thorn in my side for a while )
Thanks much!
Andy
I've always had a problem understanding why, if a space-explorer left on a ship, traveled at nearly the speed of light for a while, and then came back to earth, he might have only aged a few months whereas the people of Earth would have aged many years.
Here's what I understand:
1. I understand that every frame of reference has it's own time. Thus, the ship has different time than the earth.
2. I also understand that at faster speeds, time slows down. Thus, on the ship, time will pass more slowly than it does on earth.
Now, due to (1) and (2) - it looks like I've already answered my own question. But here's what trips me up..
3. I also understand that every frame of reference is entitled to regard itself as being "at rest". For example, if two ships pass - both have the right to say they are sitting still and the other one is moving.
So, really - my problem is the following.. isn't it equally correct to say that the space-explorer (from the first paragraph) was sitting still in his spaceship, and that the Earth zoomed away from him, traveled at nearly the speed of light for a while, and then returned back to him?? And thus, shouldn't the earth's time have slowed? So then the people of Earth would have aged only a few months and the space-explorer would be the one who aged many years?
Seems to me that both cases are true. That the earthlings would see the space-explore's time slow relative to theirs, but that the space-explorer would see the Earth's time slow relative to his. So what happens when they meet up in the end and compare watches? Who's watch is ahead and who's is behind??
I'm very excited that I just happened to stumble across this website tonight. I've read a lot of the posts and know that there are a lot of very bright people out there answering questions. I'd love to have this one solved for me (it's been a thorn in my side for a while )
Thanks much!
Andy