The star betelgeuse has a large negative absolute magnitude and a large positive apparent magnitude. what does this mean? a. betelgeuse appears to be very bright, but actually is very dim. b. betelgeuse appears to be very dim, but is actually very bright. c. betelgeuse appears to be close to us, but is actually far away.

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?