Time Dilation - Clock running slower?

Peter G.

Hi,

I am having a hard time understanding one thing about this experiment for Time Dilation.

I have one observer on a moving train measuring the time it takes for light to travel a distance d and be reflected back and one observer who is stationary, watching the same events.

I understand the man on the platform does not measure proper time and, hence, measures a dilated time period.

However, my book says that the man on the platform sees the clock held by the man on the train tick slower.

Shouldn't it be the opposite? For a fixed interval on the watch of the man on the platform, the watch on the train will have measured an inferior time period if it ticks slower, as if time had contracted, no?

Or is the book referring to the fact that the man on the platform sees the time measured by the observer on the train? In that case the watch on the train seems to tick slower because the stationary observer's watch is ticking faster?

Can anyone help me please!

Thanks!

Simon Bridge

Both observers will see the other's clock tick slower.
There is no true rate of time. "proper" is a technical term in relativity and should not be considered to have any special significance in terms of what is "really" happening.

Peter G.

Ok, thanks