EINSTEIN

• Albert Einstein


  Considered by many to be the greatest scientist of the twentieth century, revolutionized scientific thought with new theories of space, time, mass, motion, and gravitation
• Born in Ulm, Germany in 1879, grew up in Munich
• Unable to find a teaching job after graduating from a technical institute in Zurich, Switzerland, accepted a post as an examiner in a Swiss patent office from 1902 to 1909
• In 1905 Einstein received his doctorate in physics from the University of Zurich, and published three scientific papers, each of which had a profound effect on the field of physics
• Photoelectric effect


  Beams of light cause metals to release electrons which can be converted into electric current
• Einstein's explanation of photoelectric effect

  Light is composed of discrete packets, or quanta, of energy particles
• For this work, Einstein in 1921 received the Nobel Prize in Physics
• Special theory of relativity


  Explained how speed affects mass, time and space
• The two postulates of the Special Theory of relativity are: 1) the laws of physics are the same in all inertial frames of reference; and 2) the speed of light is constant and independent of the relative motion of the source
• Consequences of Special Theory of Relativity

  Time dilation and length contraction
• E=mc2


  Showed the equivalence of mass and energy
• Photoelectric effect


  When a beam of light is directed at a metal surface, the photons of light collide with the atoms of the metal. If the photon's frequency is sufficient to knock off an electron, electrons are ejected from the surface of the metal.
• Einstein's explanation of photoelectric effect

  Light is composed of discrete particles called photons
• Study of photoelectric effect led to important steps in understanding the quantum nature of light and electrons which later led to the concept of the wave-particle duality
• Applications of photoelectric effect

  • Automatic door openers
  • Light meters used in photography
  • Solar panels
  • Photostatic copying
• Brownian motion


  Irregular movement of particles suspended in a liquid or a gas, a consequence of molecular motion
• Using his Brownian Theory of Motion, Einstein showed how to calculate Avogadro's number and the size of molecules
• Einstein's paper on the sky being blue

  Examined the cumulative effect of the scattering of light by individual molecules in the atmosphere
• General Relativity


  Gravity is a curved field in the space-time continuum created by the existence of mass
• General Relativity has been used to explain the existence of black holes, light bending due to gravity, the behavior of the planet Mercury in its orbit, etc.
• In 1917, Einstein published a paper which uses general relativity to model the behavior of an entire universe
• Einstein recognized that there might be a problem with the classical notion of cause and effect due to the peculiar, dual nature of quanta as both waves and particles
• Bose Einstein statistics


  Describes any assembly of these indistinguishable particles known as bosons
• Einstein developed a refrigerator design that used ammonia, water and butane and required almost no energy to run