Contribution of Newton and Galileo to the Understanding of Force and Motion

Key Points

• Prior to 1600
  • Aristotelian philosophy - speed is proportional to force and inversely proportional to resistance
  • there is no motion without force and in the absence of force a body under motion will stop
• Galileo
  • discovered what was later called 'inertia'; the property of a body to resist changes in motion
  • relativity hypothesis - velocity must have a frame of reference
  • in absence of force an object will move in a straight line at a constant velocity
  • understood velocity and acceleration
  • argued that freely falling bodies move independently of mass (dependent upon air friction)
  • projectile motion - vertical and horizontal components are separate
  • used math an experimentation in addition to logic
  • telescope celestial bodies (motion)
  • imprisoned by the Catholic Church for supporting Copernicus view of the universe. Reversed by Pope John Paul II in 1979 who conceded that the church had erred in its judgment and asked that the 1633 conviction by the inquisition be annulled. This was finally done in 1992.
• Newton
  • universal law of gravitation
  • space and time are absolute
  • 1st, 2nd, 3rd law of motion