Cosmology
Cosmology is the study of the origin and evolution of the Universe.
It is a field of astronomy that deals with questions like:
How old is the Universe? How did it begin? Will it continue
expanding or slow down and collapse? How did the chemical elements
which make up our Universe form? Infrared spectroscopy offers
clues which may lead to answers for many of these questions.
If the Universe did begin as a hot "Big Bang", there
should still be a general background of radiation, now at an extremely
low temperature, which is the remnant heat from the Big Bang itself.
This radiation, called the cosmic background radiation, was originally
detected by radio astronomers in the 1960's. In 1993, data from a
far-infrared spectrometer
aboard NASA's
COBE was used to make the most accurate measure
yet of this background radiation and showed that it is
extremely close to that of a perfect blackbody at 2.726 K.
The plot to the right is a comparison of the predicted energy spectrum for
the cosmic
background radiation (from the Big Bang theory) compared with the
actual data taken with COBE's infrared spectrometers. The error bars
are so small that the two curves match up almost exactly - appearing as
one curve in this plot. This result was an important test of the
accuracy of the Big Bang theory.
ISO measures deuterium
in Orion and
confirms that the normal matter in the universe is not enough to cause the
"Big Crunch".
One key to determining whether the Universe will continue expanding or
eventually slow down and start collapsing is the amount of deuterium
present in the Universe. Deuterium (sometimes called "heavy hydrogen")
is a hydrogen atom which has both a proton and a neutron in its
nucleus instead of just a proton as in the hydrogen atom.
Most of the deuterium in the Universe is thought to have been created
by the Big Bang itself. Since deuterium is directly related to the
total amount of matter in the Universe, its accurate measure is
an important way to determine whether the Universe will continue expanding
or eventually collapse under it's own weight.
Infrared spectral studies using data from the
ISO satellite
have shown that there is not enough deuterium present in space to indicate
that the Universe will eventually collapse.
Infrared Spectroscopy Index |
What is Spectroscopy? |
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