Galileo devised an experiment to measure the speed of light. He and an assistant went to the top of nearby mountains and did the following.
(1) Galileo switched on a lantern that was visible to his assistant.
(2) Immediately after seeing the light from Galileo’s lantern, the assistant switched on his lantern so that Galileo could see it.
(3) Galileo then measured the interval between the time that he (Galileo) switched on his lantern and the time that he first saw the light from his assistant’s lantern. Suppose the distance between Galileo and his assistant was 5 km.
(a) What is the round-trip travel time for the light in this experiment?
(b) Do you think that this experiment was successful? The typical human reaction time is about 0.2 s.
(c) Now include the typical human reaction time of 0.2 s in your analysis and answer the following question. Approximately how far apart should Galileo and his assistant be in order to observe the contribution to the total time delay from the speed of light?