0

I know that refraction is caused due to change in speed of light but why does it bends? I also know that during refraction frequency is constant and wavelength is decreased since speed slows down. But please tell me why it bends ,it should have slowed down and passed straight?

jinawee
  • 12,381
Anirban Dey
  • 1

1 Answers1

1

Imagine a row of soldiers trying to march while locking arms. They walk on a road, and approach a sandy desert. As the first soldiers hit the sand, their foot steps get smaller - but they continue marching "in step" with the others. The line will start to "break" without them realizing it. Once they are all on the sand they have changed direction.

Usually this is shown using the Huygens construction. See for example this image source:

enter image description here

Floris
  • 118,905
  • Great analogy, never heard of it. – Ruslan Jan 23 '15 at 11:39
  • Not fully satisfied – Anirban Dey Jan 31 '15 at 09:52
  • @AnirbanDey did you look at the link for the duplicate? You should be able to find more answers there. "Not fully satisfied" is a strange comment. What are you saying / asking? Nobody is trying to "satisfy" - this is not some exam that I am trying to pass, I am trying to give an intuitive explanation. If it is unclear then try to explain what you don't get about it so I can clarify. – Floris Jan 31 '15 at 15:15
  • I believe that this "Huygens" is a coherent theory that "needs time" though and the wave front ("soldiers" associate well.). I believe it all depends on one single photon not being "refracted". - Second, beginners in the field might easily mix that up with "different speed if different wavelength in media", as soldiers might be taken to stand for different wavelengths. Thus the picture does not explain about "change of speed"; it's about time lags of start-me-ups. – Peter Bernhard Nov 24 '22 at 17:58