Nicholas Copernicus

• heliocentric model
• retrograde motion explained (animation)

Tycho Brahe

• nova stella discovery; present view (X-ray vision)
• precision astrometry

Johannes Kepler & Kepler's Laws

1. Orbits are ellipses
2. Equal areas in equal times
3. P² = a³

• simulations here and here;
• inner solar system objects in real time
• solar system motions

Galileo Galilei: Astronomer

• Galileo reporting to the funding agency
• Observations: Moons of Jupiter:
  • 1610 sketch
  • modern gallery
  • interactive tool and animation
• Observations: Venus phases
  • Ptolemaic predictions
  • Copernican predictions
  • observed phases

Galileo Galilei: Physicist

• Free body motion
• Free fall
("Tower of Pisa" experiment)