On our planet, we inhabit a calm little oasis of ordinary
solids, liquids and gases that is immersed in a perpetually blowing, roiling,
flaring erupting substance of a very different kind, called plasma. Sometimes
called the fundamental state of matter to distinguish it from its tamer cousins,
plasma makes up more than 99 percent of the visible universe. The plasma side
of the cosmic ledger includes the seething atmospheres and interiors of stars,
the wind of particles that our sun flings outward into space, EarthÕs cocoon-like
magnetosphere, the tenuous wasteland between stars and galaxies, and fantastically
energetic displays such as quasars, supernovas and parts of the compact spinning
stars that spray out beams of x-rays like some kind of hellish fire hose.
When they are artificially produced and bottled up here on
Earth, plasmas turn out to be extremely useful. We create plasmas each time
we flip on a fluorescent light or a neon sign. Plasmas etch the tiniest circuit
features on the microprocessor chips that are at the heart of our desktop computers.
Carefully controlled clouds of plasma can "rain", or deposit, thin
layers of materials onto surfaces as a crucial step in manufacturing industrial
diamonds and superconducting films. Particle accelerators much more compact
and powerful than any now in existence could emerge from experiments that are
using intense plasma waves to push electrons up to relativistic speeds. Jets
of plasma spin and maneuver orbiting satellites. Even without leaving EarthÕs
surface, however, laboratory experiments can shed light on the wider universe
of plasma phenomena, as when the shock waves produced by laser beams striking
a small spec of plasma help unravel the dynamics of an exploding star.
But no matter how cleverly we try to harness them, plasma
sometimes revert to their unruly nature: Only after decades of research have
physicists learned, by fits and starts, how to confine a plasma that is hotter
than the sunÕs core, with the goal of producing large power plants using the
same processes that causes the sun and stars to shineÐa phenomena called thermonuclear
fusion. The long struggle to make a practical fusion devices partly reflects
the challenge inherent in understanding plasma theoretically. Plasmas are so
complexÑequally rich in physics and frustrationÑthat they often beggar all description,
even by the most sophisticated theories and the most powerful supercomputers.
(Adapted from James Glanz, The Pervasive State of Matter)