A related post could be found here: https://physics.stackexchange.com/a/35468/209383

I came across this picture. I looked up an explanation from the above post for the "rays" of diffraction. However, it occurred to me that the pictures of those rays were all of light sources (or reflections), i.e. in the picture below, only the light bulbs show the diffraction patterns, but not the cars.

At first I thought it might be because of the frequencies of the light source, but it was soon being rejected as the stars and light bulbs were hot and thus emit a range of EM waves.

The other explanation was the focus of the beam as the ray from the light source could be approximated as a plane wave, whereas the secondary reflected waves might had already been diffracted. But this does not explain why the objects at far distance exhibit the same behavior. Rather, it seemed to indicate that the intensity might be the cause, which seemed to be very strange.

Why was the diffraction only occurred for the light souse?

Photo of a parking lot with diffraction patterns around lamps

  • 1
    $\begingroup$ They are not diffraction patterns. They are due to refraction in the Fresnel type lens at the front of the headlights. $\endgroup$ – Jerrold Franklin Jul 17 '20 at 9:39

All light in the image have such diffraction patterns, but the diffraction is very weak (there is an element in front of the camera designed for that purpose), so that you don't see it. The car headlights are much brighter. You can't tell from the photo because the pixels for those headlights are completely saturated.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.