The penetrating power of x-rays lets you see inside
Q:
How do X-rays allow you to see inside of things-Jon K, Albuquerque, New Mexico
 A:
Hold a flashlight against the palm of your hand and turn it on. Some of the light comes through your hand but you
can't see what's inside very well.
[NASA/MIT/H.Marshall] The X-ray jet blasting out of M87
To get a better view you need light that both penetrates better and doesn't bounce around much. That light is x-ray
radiation. X-rays are more energetic than visible light and that greater energy powers a greater penetration. The x-rays
pass through soft tissue to varying degrees and are absorbed by the denser stuff (teeth and bones).
An x-ray picture-actually a negative-shows light areas where teeth and bones blocked the x-rays and darker areas of
varying intensity where blood, muscles, and gut largely allowed the x-rays to penetrate and register on the film.
X-rays are also useful in astronomy since stars and other objects emit e-rays as well as ordinary light.
The figure shows two views of the same phenomenon: the top view is an x-ray image taken with equipment aboard
NASA's Chandra X-ray Observatory and the bottom an optical image taken with the Hubble Space Telescope (HST).
Both show x-ray jets streaming from a giant elliptical galaxy (called M87) 50 million light years away in the constellation
Virgo. The X-ray image reveals an irregular, knotty structure in greater detail than the optical picture taken by the
HST. Note: the bright spot at the extreme left in both pictures harbors a super massive black hole.
(Answered by April Holladay, science correspondent, October 3, 2001)
Further Surfing:
Concordia College: How do x-rays work?
[DiscoverySchool.com] X-rays
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