Gravity

Gravity Simulator

This simulation … Applied a geocentric coordinate system. Air friction is ignored. Covers fall and orbital motion due to Earth’s gravity. (However, the same can be applied to other celestial bodies.) Gravity Objects with mass exert … more

Earth's Revolution and Seasons

Earth’s Revolution and Seasons (WebGL)

Earth Rotation and Seasonal Changes The Earth’s rotation axis is tilted at an angle of about 23.5 ° to the orbital axis. Because of this inclination, seasonal changes occur like spring, summer, autumn, and winter. The … more

Real Size & Orbit of Earth and Moon

Real Size & Orbit of Earth and Moon

The photographs of the Earth and the moon close together that you can see on posters, etc., are designed to be easy to see. The moon’s apparent diameter is only about 0.5˚. This tells us that … more

Keplers law

Kepler’s law

Kepler and Tycho Brahe There is an astronomer before talking about Kepler (Johannes Kepler 1571 ~ 1630). That’s Tycho Brahe. Tycho Brahe (1546-1601) is a famous Danish astronomer. With the development of astronomical equipment, he left … more