Because X rays can damage human tissue severely, it is
not possible to do a hands-on activity with this type of radiation. There
is a "simulated" X-ray activity included below. So called "soft"
X rays are used for medical examinations and shorter wavelength X rays are
used to inspect industrial products. Xrays from space occur in a large array
of wavelengths, and special mirrors and detectors are required to obtain
images from space. On earth, an object to be X-rayed is placed close to
a piece of photographic film and the X-ray source turned on for few seconds.
The developed film is dark where the X rays strike it and white where the
object absorbs the X rays.
The effect of X rays can be simulated by the following
activity: Place a piece of ordinary window screen over a box. Place a pattern
made of cardboard on top of the screen. Sprinkle sand over the area of the
box. The sand (X rays) will pass through the screen to the bottom of the
box, except where they are blocked by the pattern.
Set up for the activity.
An outline of the pattern can be seen in the bottom of the box. The photographs
show the set up and an example of the pattern in the bottom of the box.
An area of no sand shows the shape of the blocking pattern.
©1997 The Exploratorium