With electromagnetic waves, shorter wavelengths mean lower energies.

Epicycles are used in a geocentric model to explain the

 When Jupiter is at opposition (see diagram), it is overhead at  

The theory that the moon was formed independently elsewhere and was later captured by the earth is considered the most likely theory to be true.

Earths albedo changes daily and seasonally due to Earths rotation and revolution that induce variation of parts of the Earths surface under the Sun.

  When light is incident on a surface (see diagram), refraction occurs when  

Solar eclipses only occur when the phase of the Moon is

During the Victorian Era the custom of wearing black happened because:

The magnetic field of a planet is produced by

What does the red and white stripe on the barber’s pole signify?