Thin Film Interference and the Michelson Interferometer

Dr Mike Young covers Thin Film interference and also the Michelson Interferometer.

[sashaerceg]

1) If we know that light beam is reflected many times from both sides of the glass, this means that we should see a little blurred image of the source on the screen. Because, first beam splits into two, one goes up to the screen (let's say 90%), other enters the glass (10%), then part of it exits through the glass and other part goes up and splits again, from which one part goes to the screen little shifted and the other back into the glass, etc.. Is that observable?

2) At 31:45, someone asked: "So, the bright side would never be as bright as the original beam, right? Because, some of the light had to go to the other side...". I think that Dr Mike didn't explain very well, saying that ray passing through the glass will, let's say, cancel itself, so the bright side would be as bright as the original beam. As I previously explained a principle from my understanding (I'm not a physicist), after refraction beam can not have the same "brightness" any more. In our case it is 90% + some shifted rays of few percents.

3) At 32:10, that guy asked: "That light has to go through the other side and it doesn't get canceled until the other beam gets to it. So, how does the energy gets back to the original?". It looked like checkmate, but I have to point out what Dr Mike said, that there is no energy in the light beams (waves). Anyway, some "brightness" is definitely lost.

[TheFadime]

what you are drawing with the second reflection between the n=1.5 and n=1 is wrong. Beam should make a bigger angle with the plane of incidence than what you are drawing.