CTID1974 said:
wireblue said:
Your stop watch on the spaceship would tick over at exactly the same rate as the stop watch on earth. Within your spaceship time would appear to be happening at exactly the same rate - so five minutes on your stop watch would feel exactly the same as 5 minutes on the stop watch on earth. You don’t start running round like a benny hill sketch!
However the two stop watches relative to each other would be different
thats the bit i can't get my head round :|
further reading required, several years worth it would seem
anyone got a time machine ? haha
There's a reason you can't get your head around it and that's because it's not supposed to make sense. Physics isn't designed in such a way as to be nice and easy for human beings to comprehend. It is what it is, and some of it is extremely anti-intuitive.
The only way to understand these things and to come to conclusions like the one relating to the stopwatches above is simply to do the mathematics and thought experiments behind them.
I'm just saying this because there is more than one person on this thread saying something along the lines of "I must be a bit thick because it doesn't make sense to me," and that's not true at all. The fact you don't understand it is just a natural consequence of your daily experiences. We don't see things travelling at relativistic speed, so to the average person the whole thing will not make intuitive sense.
On another tangent, it is important to note that it's not
just when travelling at relativistic speeds that you 'travel through time' so to speak. It happens for every single journey you do, it just only becomes noticeable when you get up to extremely high velocity. Somebody used the example before of something like "if I go to Blackpool and back on a bus, would the kids have aged faster?" Yes, they would have, just not a great deal. If you're in a pub with your identical twin and you leave him to get a round in, then when you get back, your identical twin would be older than you.
We are talking such negligible amounts of time, though, that you wouldn't recognise any such change, in fact even with our best clocks you probably wouldn't. It is only at these high speeds which you do.
It is important to realise, and this is a fundamental point. That 'time' is
not a human invention, the way in which we measure time is a human invention, but time itself is very real and is what we call 'physical' (i.e. it happens). The time in these situations dilates because it has to for the speed of light to remain a constant to everybody no matter what speed they're travelling at ( this is the fundamental principle which guides special relativity).
Do we know 'why' the speed of light has to be the same to every observer? I certainly don't know, but it's a postulate proposed by Einstein, and it has been shown to work. The mathematics says this happens, and experiment says it does also. That's all there really is to it.
