two_heads_talking wrote:paul_b wrote:two_heads_talking wrote:

if one were to remain stationary and one were to travel 8 light years.. 20 years would pass for the stationary twin while only 12 would pass for the travelar.. and even in all this they would meet up in same time and place ..

Dude, your maths sucks. That would only be the case if the one that travelled 8 light years did so at the speed of light.

Assuming that the travelling twin was travelling for the entire 20 years, further assuming that said twin's acceleration vector was always directly away or directly towards the origin point and that said acceleration was always at the same magnitude determine how much time passed for the travelling twin.

Show your workings.

IT ASSUMES THE traveler was travelling at 80% of light speed. and this is the best place to see what i am talking about..

In the case that the traveler was going that fast then you are correct. The clock of the stationary person would be running faster than the person going 80% the speed of light. To understand this, picture a particle of light bouncing between two mirrors. Lets say that when the particle hits one side and returns to its original position amounts to one second. When you start to move the mirrors, the distance the partical increases because the path of travel is no longer horrizontal but is diagonal thus taking more time to complete one cylce which I defined to be one second. That is why the person moving will seem to be have a slower time than the moving person. So the numbers two_heads_talking used are correct if you are moving with a velocity close to the speed of light. But in the case of my original example, I said they were drifting which implies they were not moving close to the speed of light so the numbers would not be as large as two_heads_talking said.