Physics

• Study of Motion
• Newton- Philosophiae Naturalis Principia Mathematica
• Galileo- Discourses and Mathematical Demonstrations Relating to Two New Sciences
• Kepler- Mathematical Description of Motion
• Brahe- Measurement 

Newtons Laws of Motion

1. If an object experiences no net force, then the velocity is constant, the object is either at rest (if its velocity is 0), or if it moves in a straight line with constant speed ( if its velocity is not zero). 
2. The acceleration (a) of a body is parallel and directly proportional to the net force (F) acting on the body, i in the direction of the net force, and is inversely proportional to the mass (m) of the body. (F=ma)
3. Every action has an equal but opposite reaction. 

• Kepler's Laws derived from Newton's Laws
• From general to particular
• Newton's Laws don't work for measuring Mercury's orbit
• Einstein's Laws give us Mercury's orbit
• Laws of Physics are invented by physicists
• Laws of physics change when new knowledge is available
• Predictions when validated by observations are the only conditions
• Mathematics work for nature (so far)