Light rays from the sun appear to the naked eye as white light, but each ray contains a broad range of wavelengths

The German passenger airship  Hindenburg caught fire and was destroyed during its attempt to dock with its mooring mast at Naval Air Station Lakehurst.

Shuddhi Movement was started by Arya Samaj to bring back the people who transformed their religion to Islam and Christianity from Hinduism

A lunar eclipse occurs when the Moon moves into the Earth's shadow.

This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned with Earth between the other two, and only on the night of a full moon.

Braun was a German-born American aerospace engineer and space architect. 

Plimsoll line a marking on a ship's side showing the limit of legal submersion when loaded with cargo under various sea conditions

MRI, and the detailed images it produces, has been a huge benefit for the study of the brain.

Its greatest innovation is allowing us to see which parts of the brain have been damaged while a patient is still alive.

Type of goat

Elasticity is the property of solid materials to return to their original shape and size after the forces deforming them have been removed.

Periscopes allow a submarine, when submerged at a relatively shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air.

When not in use, a submarine's periscope retracts into the hull.