00:01
In this problem, we're going to talk about length contraction.
00:03
So consider that we have a reference frame, i'm going to call it s, where a certain object is at rest.
00:13
We call this object's length l.
00:17
This is the proper time, i'm sorry, the proper length of the object.
00:21
And it's special because it's the maximum length that can be measured.
00:26
And it's measured in the reference frame where the object is at rest.
00:30
Now, consider a second reference frame.
00:32
I'm going to call it s -prime.
00:36
According to who, the first reference frame is moving with a certain speed s.
00:41
Now, notice that the object is not at rest anymore.
00:46
Not certain speed v, i'm sorry.
00:47
S is just the reference frame.
00:49
The object is not at rest anymore.
00:52
It's moving with the speed v relative to the s -prime reference frame, and the length, l, measured by the s -prime reference frame to 4...