Share This
AJAX progress indicator
  • a

  • absolute constantAn absolute constant is a number that has the same value wherever it appears. Examples: π (pi) has the value 3.14159…(...) Read More
  • absolute space(Absolute space has recently been re-conceptualized and re-named as space that has "background-independence.") The(...) Read More
  • absolute square of a complex numberThe absolute square of a complex number is calculated by multiplying it by its conjugate. (The absolute square is not the(...) Read More
  • absolute timeThe concept of absolute time was a foundational concept of physics as articulated by Isaac Newton in the 1600’s. It was(...) Read More
  • acausal“Acausal” means not having a cause. In classical physics all events are believed to have a cause; none are acausal. In(...) Read More
  • accelerationAbbreviation: a In physics, acceleration is speeding up, slowing down, or changing direction. Acceleration contrasts(...) Read More
  • action-at-a-distance  Action-at-a-distance is the creation of an effect without physically touching. An example is magnetism: a magnet pulls(...) Read More
  • algebraic constantAn algebraic constant is a symbol that represents an unchanging number or is simply a number in an algebra equation. The(...) Read More
  • alphaIn quantum physics, the ancient Greek letter α, alpha, represents an important constant of nature. Alpha is .00729735256…(...) Read More
  • amplitude of a waveThe amplitude of a wave is its height, that is, half the distance from trough to crest. Amplitude can be measured for water(...) Read More
  • ancient physicsAncient physics was the physics of the ancient world, that is, of the Egyptians, Greeks, Indians (of India), and other(...) Read More
  • angular momentum(Symbol is L. Also called “rotational momentum” or “moment of momentum.”) Angular momentum is the momentum or oomph which an(...) Read More
  • anomalyAn anomaly is an experimental result or an observation that doesn’t fit current scientific theories. Sometimes anomalies(...) Read More
  • antimatterAntimatter is not just the stuff of science fiction. It is as real as ordinary matter. Physicists call the matter that we(...) Read More
  • antiparticleAn antiparticle is an antimatter version of a normal particle. For example, an antiquark is an antimatter quark. An(...) Read More
  • atomAn atom is the tiniest component of an element which shares in the element’s properties. Break down matter any further and(...) Read More
  • atomic numberThe atomic number of an atom is the number of protons in its nucleus. For example, an atom of carbon has six protons and has(...) Read More