What we know about dark matter and what we have yet to discover
Astronomical observations have confirmed dark matter's existence, but
what exactly is dark matter? In What Is Dark Matter?, particle
physicist Peter Fisher introduces readers to one of the most intriguing
frontiers of physics. We cannot actually see dark matter, a mysterious,
nonluminous form of matter that is believed to account for about 27
percent of the mass-energy balance in the universe. But we know dark
matter is present by observing its ghostly gravitational effects on the
behavior and evolution of galaxies. Fisher brings readers quickly up to
speed regarding the current state of the dark matter problem, offering
relevant historical context as well as a close look at the cutting-edge
research focused on revealing dark matter's true nature.
Could dark matter be a new type of particle--an axion or a Weakly
Interacting Massive Particle (WIMP)--or something else? What have
physicists ruled out so far--and why? What experimental searches are now
underway and planned for the near future, in hopes of detecting dark
matter on Earth or in space? Fisher explores these questions and more,
illuminating what is known and unknown, and what a triumph it will be
when scientists discover dark matter's identity at last.