Double slit diffraction confusion

This is from the A Level CGP Textbook:

"In order to get clear interference patterns, the waves from the two sources must be monochromatic and coherent"

Then it describes Young's Double-Slit experiment:

"If you were to use a white light source instead of a coherent monochromatic laser, the diffraction pattern would be less intense, with wider maxima."



Can someone explain why you can use a white light source when it clearly says the double slit experiment requires monochromatic light?

And I'm also confused why the diffraction pattern would have less intense and wider maxima?

Also, what is the reason that the central maximum is white for white light? Does it simply pass through?

You can use light that isn't monochromatic, but it isn't as clear

The middle fringe is white because every colour goes to that point in the centre and contributes to the white colour.


Posted from TSR Mobile

Thank you.

For the central maxima, does the light pass straight through, since the whole of the middle fringe is white?

If that's not the case I still don't understand why the central is white, I would have expected it to be more violet in the centre and then more red on the edges of the middle fringe? We were taught this very badly soo

I had a very bad teacher for AS too

I just read it straight from the book

I don't think it goes straight through though


Posted from TSR Mobile

Hey, at least you don't have to do the new spec AQA Physics A Level! I actually have to revise AS (and A2 ofc) properly as a result, the exams are damn hard...

Yeah

But now uni is going to be so difficult, maxwell's equations and **** like that


Posted from TSR Mobile

gl with that my man,

I'm not doing physics at degree level! Doing economics instead

.....
Also, what is the reason that the central maximum is white for white light? Does it simply pass through?