# Homework Help: Question about Diffraction Grating

1. Oct 18, 2005

### insertnamehere

Hello.
I just want to clarify something about the following question:
WHen you receive a chest x-ray at a hospital, the rays pass through a series of parallel ribs in your chest. Do the ribs act as a diffraction grating for x-rays?

My answer is yes, as the spacing between the ribs can act as a slit spacing, and as the x-rays diffract from these slits/ribs, they can interfere on the screen, resulting in bright and dark fringes...but I'm not too confident about my answer...HELP! am i on the right track?

2. Oct 19, 2005

### sanitykey

The closer that the spacing between two objects is compared to the wavelength of the em-radiation such as x-rays the more diffracted the waves are, x-ray wavelength is approximately between 10*10^-9m and 10*10^-11m.

Since the spacing between these ribs is a lot bigger than this wavelength i'd say no, the x-rays are being diffracted but not because of the spacing between the ribs but because of the other mediums through which the x-rays are travelling such as less dense tissues. The reason x-rays don't pass through bone is because it is too dense (the spacing between the bone particles is too small).

Hope this helps, also please correct me if anything i've said is wrong, (this is off the top of my head except the wavelength :) )