Problem Set 0

Prof. Smoot's Physics 139 class

Due Week January 19, 1999

1. Aberration of Starlight: What is the aberration of starlight? What was it about Bradley's measurement that makes it noteworthy?

2. Frames of Reference: When we ask some one to measure the length of an object, what do we really mean? For example, consider a person waiting at a railway crossing as a train is passing, and you ask him to measure how long the train is. If he replies, that it is 67 cars long, is that a clear result? Will all observers agree with him? What if he says it was also zero feet long, since he measured the first car (locomotive) leading edge got to the crossing, and when the last car (caboose) trailing edge got to the crossing (some two minutes later). Isn't the second measurement also correct, but not what you meant? Why do you want to either specify the measurement procedure very precisely or in terms of invariants?

3. Michelson and Morely Experiment: What is the most important thing ever to have happened in Cleveland? What was the experiment and the results?

4. c - fundamental constant

5. How was the speed of light best measured? How is it determined today?