To start
with, to know what a spectrum is: when white light is shone through a
prism it is separated out into all the colors of the rainbow; this is the
visible spectrum. So white light is a mixture of all colors .Black is NOT a
color; it is what you get when all the light is taken away. Some
physicists pretend that light consists of
tiny particles which they call photons.
They travel at the
speed of light (what surprise).
The speed of light is about 300,000,000 meters per second.
When they hit something they might
bounce off, go right through or get absorbed. What happens depends a bit on how
much energy they have.
If they bounce off
something and then go into your eye you will "see" the thing
they have bounced
off. Some things like glass and Perspex will let them go through; these
materials are transparent.
Black
objects absorb the photons so you should not be able to see black things: you
will have to think about this one. These poor old physicists get a little
bit confused when they try to explain why
some photons go through a leaf, some are reflected, and some are absorbed. They
say that it is because they have different amounts
of energy. Other physicists pretend that light is made
of waves.
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