In this three-part documentary series from the BBC, Professor Jim Al-Khalili tells the story of one of the greatest scientific discoveries ever: that the material world is made up of atoms.

Part 2. THE KEY TO THE COSMOS This episode tackles world-changing discoveries such as radioactivity, the Atom Bomb and the Big Bang, and tries to answer the biggest questions of all – why are we here and how were we made?

 

Astrophysics

astrophysics –noun (used with a singular verb) reference: Dictionary.com Unabridged (v 1.1)
the branch of astronomy that deals with the physical properties of celestial bodies and with the interaction between matter and radiation in the interior of celestial bodies and in interstellar space.
Origin:
1885–90; astro- + physics