Astrophysics terms starting with P

11 terms

  1. Parallax A method of finding astronomical distances. One uses a super distant background of stars as a reference plane, and observes the difference in position of…
  2. Parsec A unit of distance, derived from a technique of finding distances to astronomical objects, called parallax. 3.1 x 1013 km or 3.26 light years.
  3. Particle Accelerators A machine used to accelerate particles to high speeds, and thus, high energy compared to their rest-mass energy.
  4. Particle Physics The study of fundamental particles (such as quarks and leptons) and the fundamental interactions (four forces).
  5. Period Usually designated by T. This is the time interval of one complete oscillation of any wave. See Wavelength.
  6. Phase Transition Change from one state of energy to another.
  7. Photon A photon is both a wave and a particle. A beam of light is composed of these particles.
  8. Planck Time The period of time immediately after the creation of the universe (10-43 s) during which quantum gravity is the principal phenomenon governing the…
  9. Plasma (PLAZ-muh) The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.
  10. Positron The antiparticle of the electron, carry a charge that is opposite to an electron.
  11. Primordial Nucleosynthesis Building of the atomic elements in the early universe when nuclei fused with one another. Most of the helium in the universe was created by this process.