# Problem Set 0

## 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

• What is special about the speed of light?
• What do Maxwell's equation tell us is the speed of light?
• How does that depend upon one's reference frame?
• How does that depend upon the speed of the observer?
• How does that depend upon the speed of the emitter?
• How does that depend upon the speed of the transmission medium?
• What is the speed of motion of any massless object?

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

6.