I am really sorry for the late reply. Exams really put a stop to self-studying.
Ok, to find how many wavelengths there were in the cell originally under a vacuum, we can divide 2d by the wavelength of the light. So, in the new gas environment, the number of wavelengths is 2d divided by the new...
Thanks for the welcome.
Ok, so the wavelength of light in a medium that's not a vacuum can be found by
new wavelength = (wavelength in vacuum) / (index of refraction)
So, the gas will cause the beam to be out of phase compared to the other beam due to the temporary change in wavelength...
Homework Statement
Giancoli Ed. 6, Ch. 24, #52
One of the beams of an interferometer passes through a small glass container containing a cavity 1.3 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light...