- Electromagnetic Spectrum:
- The electromagnetic spectrum is important to understand as
a number of environmental issues depend on it.
- Electromagnetic energy is in the form of waves, with the
different types characterized by the energy associated and the
wavelength. For example gamma rays are very high energy, but
with short wavelength. Radio waves are low in energy, but long
in wavelength. Visible light is somewhere in the middle, all
of the other waves are invisible to the human eye, but may be
measured with various instruments.
- Environmental Effects of Electromagnetic Radiation:
| Cosmic rays, gamma rays, and X-rays
are important to understanding nuclear radiation. The energies
are very high and will break bonds in molecules and ionize atoms
| Ultraviolet radiation is important
in understanding the formation and function of the ozone layer
in the protection from skin cancer. The energy of UV radiation
is sufficient to break bonds in some molecules.
| Infrared radiation is important
to understanding the Greenhouse Effect and global warming. The
energy is much lower and is only able to vibrate and bend atoms
involving bonds of molecules.
| Microwaves are used for cooking
because the energy is quite low but sufficient to cause the rotation
of water molecules. This eventually causes the remaining molecules
in the food to heat up.