Electromagnetic radiation (EMR) provides all our information about the physical Universe, apart from meteorites and lunar rock samples....

In 1842 Christian Doppler hired a group of musicians to play on an open train carriage as it was moving on the track and he heard a...

Gravity is a universal force. It is one of the four fundamental forces that act on us all the time. The strong force and the weak force...

A variable star's apparent brightness changes over time as seen from Earth. There are 2 basic types: intrinsic variables whose luminosity...

Quasars are the brightest & most distant objects in the known universe. The name quasar comes from "quasi-stellar radio source" & they...

Hubble’s Law or the Hubble-Lemaître law shows that there is a direct correlation between the distance to a galaxy and its recessional...

Cosmology is a branch of astronomy involving the origin, structure and evolution of the Universe as a whole. It deals with phenomena at a...