But it still moves...
-Galileo
Note: This lecture completes the timeline from ancient Greece to the 20th century. Study the timeline, which summarizes the major names and ideas presented in the first part of your textbook.
Galileo (pic1, pic2) experiments in Pisa on motion of falling bodies and the pendulum. Results challenge Aristotle's physics of natural and forced motions.
Did not invent telescope, but first to use it on the heavens.
He provided strong experimental evidence for Copernicus' Heliocentric model by observing the:
Put on trial by the Inquisition for his "heretical" views.
Isaac Newton (picture)
The problem of the motion of the Moon made my head ache and kept me awake so often that I would think of it no more!
-Newton (to Halley)
Law 1. The Inertia Law: A body continues at rest or in uniform motion in a straight line unless acted upon by some force.
Law 2. The Force Law: A body's change of motion (acceleration) is proportional to the force acting on it (and inversely proportional to the mass) and is in the direction of the force.
( or mathematically: a = F/m or F=ma)
Law 3. The Reaction Law: When one body exerts a force on a second body, the second body exerts an equal and opposite force back on the first body.
( or: for every action there is an equal but opposite reaction. )
Also, you must understand the definitions of velocity and acceleration to understand these laws:
Both velocity and acceleration have a magnitude and direction.
Newton's apple: an apple and the moon both follow same universal law of gravity (Newton's original orbit drawing) or Chaisson Fig2.27
Newton invented a new branch of mathematics (calculus) in order to work out the consequences of his theory (e.g., the derivation of Kepler's laws, explanation of tides, the orbits of comets)
Theory of Relativity (all motion relative, all frames of reference equal)
Gravity as curved spacetime (not a force) which warps space (c.f., Chaisson Chap 22, section 6)
Unified Theory "to know the mind of God" (pic1, pic2)
Chaisson: Chaps. 2, 22.6
The Galileo Project from Rice University.
The timeline shown in class.
L'Istituto e Museo di Storia della Scienza [IMSS] has an digital archive of Galileo's actual manuscripts (yes! you can read the actual books and notes while sitting at your computer.)
Calculus-ridden chalkboard taken from the MIT's OpenCourseWare
Document URL: http://www.uh.edu/~jclarage/astr3131/lectures/4/4.html
