In this post, it is mentioned:
“When the path difference between those two paths is equal to the wavelength of the light, those two contributions are cancelled out (there is a phase shift of 1800 for the two paths in addition). That is why one sees zero intensity at plate thicknesses that are multiples of even number of half the wavelength.
On the other hand, when the path difference between those two paths is equal to the half of the wavelength of the light, those two contributions add together.”
Is this the standing waves of transmission line theory? I studied electromagnetism back in my uni days and it is good to use science to help me gain confidence in Buddha Dhamma.
We know that light travels at 3×10^8 m/s in vacuum. And if light is made to pass through a medium like glass, it is going to slow down much more. As the light bounces off the first glass surface and gets reflected off as arrow #1, it has to ‘wait’ for its much slower counterpart that is transmitted through the glass that gets reflected on the other side of the glass and emerges as arrow #2 and reunion with arrow #1. But wait a minute, the reflected light taking path #1 doesn’t know the medium which its counterpart is taking and certainly doesn’t know how much slower it is going compared to itself. So how can both meet at the same point? Nature has a way to readjust itself. Regardless of how thick the glass is, as long as it is relatively free from impurities, the above observation will hold true. Hope I understand this post correctly.