White light passing through prism

[hendrix7]

Homework Statement

Why don't the individual colours of the spectrum rejoin to form white light on exit from a prism?

Relevant Equations

n/a

I don't really have any idea. I know that shorter wavelengths refract more on entry to prism; e.g. ultra-violet refracts more than infra-red, but I don't know why they don't join up again when speeding up on exit from the prism.

 

[BvU]

Hi, and

​

Here at PF, you are supposed to do some work of your own before we can assist.
See
https://www.physicsforums.com/threads/homework-help-guidelines-for-students-and-helpers.686781/

Homework Statement: Why don't the individual colours of the spectrum rejoin to form white light on exit from a prism?
Relevant Equations: n/a

I don't really have any idea

'No idea' is not enough. Do some googling !

$\$

 

[hendrix7]

Hi, and

​

Here at PF, you are supposed to do some work of your own before we can assist.
See
https://www.physicsforums.com/threads/homework-help-guidelines-for-students-and-helpers.686781/
'No idea' is not enough. Do some googling !

$\$

Sorry, earlier replies in error. Thank you BvU; very helpful.

 

[berkeman]

'No idea' is not enough. Do some googling !

Or listen to more Pink Floyd...

https://news.artnet.com/news/squaring-the-circle-hipgnosis-documentary-anton-corbijn-2317872

 

[BvU]

Homework Statement: Why don't the individual colours of the spectrum rejoin to form white light on exit from a prism?
Relevant Equations: n/a

why they don't join up again when speeding up on exit

Which way does the refraction upon exit work ? Towards joining up or towards even further splitting ?

Consider three cases:

• as in @berkeman Pink Floyd gramophone record sleeve picture,
• when sides are parallel (flat glass plate)
• as in @berkeman Pink Foyd gramophone record sleeve picture upside down

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