Physics

Physics is the natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.

Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy. Over the last two millennia, physics was a part of natural philosophy along with chemistry, certain branches of mathematics, and biology, but during the Scientific Revolution in the 17th century, the natural sciences emerged as unique research programs in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysicsand quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms of other sciences while opening new avenues of research in areas such as mathematics and philosophy.

Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs. For example, advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products which have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

http://en.wikipedia.org/wiki/Physics

• Comet
  
    * Every 26 million years Earth will be hit by a comet.
  
• Black Hole
  
   * Point of no return.
   * Greater than speed of light.
   * In 1967, John Michell called invisible stars as black holes.
  
  
• Planetary Motion
  
  *Tycho Brache
  
  * Johannes Kepler
     -Three Laws of Planetary Motion
       1.First Law of Ellipses - The path of the planets about the sun is elliptical in shape, with the                                            center of the sun being located at one focus.
  
       2.The Law of Equal Areas - An imaginary line drawn from the center of the sun to the                                                       center of the planet will sweep out equal areas in equal intervals                                                 of time.      3.Harmonic Law --> (T1/T2)² = (r1/r2) - 
  The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun.
  
  
  http://www.physicsclassroom.com/Class/circles/u6l4a.cfm