Today, I was tutoring and explained the space-time. I explained how one can convert North-South into West-East by rotating, and how you can convert time into space with velocity.
Below the Energy-Momentum stuff the book had some problems. One was the following:
Given an event at (1 Lightsecond, 2 s), give it's coordinates in a frame of reference that is moving with 0.6 of speed of light to it.
This the diagram I came up with, in blue there is the event. (Not really to scale.)
Then I projected the point onto the orange axes, and I get smaller values on each. This makes sense to me, as a moving observer would see thing smaller and slower, resulting in less values in either measurement.
But how do I get the orange lines? I cannot see how I get this angle. If I got them, I could tell you the speed of the reference frame, but the speed is given here …
And did I do the projection of the speed right?