Spectrum
The universe is full of electro-
magnetic radiation, which travels
in waves. Our eyes see a small
range of these waves as visible
light, but we can also detect
the effects of other
radiation types.
SCIENCE
To remember the colors of
the visible spectrum in order,
memorize this phrase: “Roy G.
Biv”, for Red, Orange, Yellow,
Green, Blue, Indigo,
and Violet.W
OW!
THE ELECTROMAGNETIC SPECTRUM
The visible spectrum is a small part of a much larger
spectrum of energy waves. We have found technological
uses for most types of electromagnetic radiation.Because short
wavelengths refract
more than long
ones, the different
wavelengths of the
spectrum are
separated by
the prism.Prism
GAMMA RAYS X-RAYS ULTRAVIOLET (UV ) VISIBLE RAYSGamma radiation
is immensely
powerful. In large
quantities it
damages our cells
and DNA.X-rays pass
through our
bodies. We
can use them
to take pictures
of our insides.Ultraviolet
rays damage
our cells.
Sunscreen or a
suntan can help
filter them out.Visible light
waves make the
world a colorful
place for us
to experience
and enjoy.The wavelengths of different types
of electromagnetic radiation range
from shorter than an atom to
millions of miles long.RAINBOWS
We see rainbows when white
light is refracted as it passes
through different media,
such as drops of water or
thin layers of oil. Sunlight
passing through rain or mist
from a fountain creates
rainbows, and we see them
produced by solid materials
such as crystal or perspex.When waves strike the surface of a
different medium at an angle,
they are bent by an amount that
differs slightly for different
wavelengths. The bending is
known as “refraction”.White light contains
a mixture of visible
wavelengths.WAVELENGTH242
(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.