Earth Science: Geology, the Environment, and the UniverseChapter 3:
Matter and Atomic StructureProblem of the WeekIn What State Do You Exist? If you were to stand on a corner of a busy street
and ask passers-by the following question, "In what states can matter
exist?" would most folks, probably answer, "Oh, that’s easy,
there are three, solids, liquids, and gases." What would be your
response to their answer? Right or wrong? They would be wrong. From what
we know, there are four states of matter: solids, liquids, gases, and plasmas.
Solids, liquids and gases are very familiar in our lives, but matter, as
plasmas, is a relatively new idea. Plasmas have been in existence since
the very beginnings of the solar system. They exist at very high temperatures
and consist of freely moving electrons, which have been stripped from the
nuclei of atoms, and ions. Plasmas are much more common than you would think.
"In fact, ninety-nine percent of the universe is in some form of
a plasma state, including lightning, very hot flames, nebulas, the Sun,
and other stars." "Courtesy of SOHO consortium.
SOHO is a project of international cooperation between
ESA and NASA." The gases on the sun exist as plasmas." (117.0K) Here on Earth we see plasmas as lightning, in
lighting devices like neon signs, and in the Aurora Borealis. What really
makes plasmas special though, is their potential, earthly role in the
production of a virtually inexhaustible source of energy through the process
of nuclear fusion. Plasmas are the key to nuclear fusion, which
can be simply defined as the combination of lighter atomic nuclei into
heavier nuclei, resulting in the release of energy. Scientists believe
that the fuel for the fusion process is hydrogen, an element found in
abundance on Earth, in the form of water. In order for fusion reactions
to occur, the particles must be hot enough (temperature), in sufficient
number (density), and well contained (confinement time). The intense gravitational
forces present in stars provide these conditions and plasmas exist there
naturally. Intense research is currently being conducted to sustain nuclear
fusion on Earth. The results could lead to a reduction in energy problems.
What is the Problem? Read again the conditions that are required for
fusion to occur: - Check out the following Web site to find out the temperatures required
in order for fusion to occur: (Shockwave plugin is required.) How hot?
http://ippex.pppl.gov/ippex/MODULE_5
/Forces/FUSION_VS_TEMP.HTML
- Fusion is such an efficient way to produce energy. Make some educated
guesses as to why we aren't using it on Earth now.
- Review again, the conditions that must be present to maintain a fusion
reaction; besides the problems with temperature, are the other two conditions
reproducible on earth? What do you think? Why or why not?
Hopefully this Problem of the Week has whet your
appetite and you want to know more about plasmas, fusion, and the important
research being done to harness the power of the stars here on Earth. Check
out these "student friendly" and fun Websites and activities
to find out more. - About
Fusion – a tutorial, which explains the process of fusion
and fusion research.
- Fusion
Energy– each link takes you to an interactive activity
that allows you to investigate the forces involved in making fusion
happen.
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