he space within our solar system and around stars and nebulae is
filled with ionized particles known as plasma. Plasma makes up the solar
wind, produces auroras, and constitutes the "weather" part of space weather.
In space, the particles are mainly protons and electrons. Much of the behavior
of plasma is dominated by electrons because of their higher mobility.
The first section of this book (chapters 1-5) is a review of electromagnetism and
kinetic theory from undergraduate physics. The equations are explained pretty well,
although this section is none too exciting, and I experienced an almost irresistible
temptation to skip to chapter 6.
The second section (chapters 6-10) discuss space plasmas. Little of the
math in the first section is used, and the emphasis is on providing a
qualitative understanding of space plasma and its effects. The third
section is 20 pages on instrumentation.
There are many graphs, diagrams and equations (using vector calculus and other
standard physics-type stuff). About half of the figures are messed up with
strange computer glitches, making them uninterpretable. There are some
solved example problems, 573 references, and even a little tensor calculus,
but the dry writing style make the subject seem more abstract than it really is.
Take, for example, the discussion of whistler waves on p.235:
whistlers are pure EM phenomena, and although they might be ducted in a planetary
waveguide, they couldn't just be trapped like electrons in a magnetic field as the
author says. After re-reading it several times, it becomes clear that's probably
what she was actually trying to say; but it's obscured by the clumsy writing. A bit
of editing (and maybe some new graphics software) might give the 4th edition of
this book the greater readership this topic deserves. The amazing beauty of these
phenomena (auroras, solar wind, and solar flares) has the ability to inspire awe
in students and professionals alike.
A more readable, if somewhat more mathematically intimidating, treatment,
is Plasma Physics for Astrophysics by R. M. Kulsrud.
jul 21, 2012
hat better time than December 21, 2012, the official scheduled date of the
End of the World, to read a book on nuclear physics?
Understanding the
phase transition between quark plasma and hadronic matter is of immense scientific
importance.
Strong interactions
hold hadrons together in the nucleus, but the behavior of quark-gluon plasma,
which is only formed at densities above
2-3×1045 hadrons / m3
(which occurred only for the first ten microseconds after the Big Bang), is
still a mystery.
Gluon-mediated interactions between spatially separated quarks are analogous to
photon-mediated interactions between spatially separated charged particles, which
create electromagnetic radiation.
Indeed, quantum chromodynamics predicts that
much of the mass in subatomic particles may come not from the quarks themselves,
but from a dynamical effect of how they are confined.
Inside hadrons, says Satz, quarks polarize the gluon medium, which thereby
creates mass. In some models, acquisition of quark mass is described as a
breaking of chiral symmetry which occurs in the hadronic phase.
Thus, strong interaction physics
may help us understand not just the fundamental properties of matter, but also mass
and gravity.
In quark-gluon plasma, no one can
hear you scream, because the speed of sound approaches zero.
In layman's terms, this means if you want to discover how the world was destroyed
last December 21 (or not, depending on whether you are reading this as a spirit or
as a corporeal being), this book will help you understand what happened to it.
After reviewing Ising spin glass thermodynamics and symmetry breaking, Satz
discusses the remarkable result of Hagedorn and others indicating that, just as
there is an absolute minimum temperature, matter may also have a maximum
ultimate temperature. Even an infinite amount of energy cannot raise matter above
this maximum temperature, which Hagedorn estimated to be 0.15 GeV, or 1.74 trillion
degrees. This temperature marks a phase transition point to quark deconfinement.
Satz describes how the Ising model can be used to create a lattice formulation of
statistical QCD, and shows how pure SU(3) gauge theory and full QCD simulations both
predict a sharp transition to deconfined plasma. He then discusses the phase
structure of matter at high baryon densities and considers the properties of
the (as-yet unobserved) quark-gluon plasma that lies beyond.
Unfortunately, the world ends next Friday, so it's all of only academic interest
now. But still, fascinating stuff. Background in physics is recommended, especially
for the chapter on gauge theory.
dec 16, 2012
