# Diffraction grating

1. Jan 29, 2006

### UrbanXrisis

I am asked to describe how the theory of diffraction grating allows us to understand the extreme sharpness of irridescent colors seen coming from beetles, bird feathers, butterflies, etc. Then, explain if this occurs in all natural objects that being with the letter 'b.'

I am not quite sure what the question as asking. I understand defraction but how could a feather, or a beetle defract light? When light bounces off of the beetle, is there a diffraction grating on the beatle that changes the light into different intensities when I look at it from variable angles? And what about all natural objects that being with the letter b?

2. Jan 29, 2006

### mrjeffy321

When you look at the shinny side of a CD, you see a rainbow effect, this is due to a diffraction patter caused by the tiny bumps on the CD surface which the data in encoded onto.
If you look at the wing of a buterfly for instance (because there is a picture in a my book) under a microscope, you can see that it is not solid, but actually has lts of tiny holes in it causing the same type of diffraction effect as on a CD.

Is the second part of the question a joke? I dont think that the letter of the alphabet the object starts with has anything to do with diffraction.

3. Jan 29, 2006

### UrbanXrisis

but a CD, isnt that reflection? I thought defraction was light going THOUGH slits to cause defraction. how is just bumps on a cd labeled as defraction?

4. Jan 30, 2006

### mrjeffy321

The very tiny bumps on the CD can act like a diffraction grading, causing part of the light reflecting off to be out of phase with the rest of the light.
There must be a diagram of this out there on the internet somewhere, but I cant find one to demonstrate. I did however scan in the picture from the book of the butterfly wing.

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5. Jan 30, 2006

### Astronuc

Staff Emeritus
Last edited by a moderator: May 2, 2017
6. Feb 1, 2006

### UrbanXrisis

does diffraction occur in all natural objects?