ID3+lab1

= **People and events** =

=__Nine important events:__=
 * 1- Max Plank discovers the quantum nature of energy.
 * 2- Henrietta Leavitt discovers the relationship between Cepheid period and luminosity and their distance from earth.
 * 3- Albert Einstein publishes his General Theory of Relativity.
 * 4- Edwin Hubble discovers a new galaxy.
 * 5- Georges LeMaitre proposes the theory of an expanding universe.
 * 6- Edwin Hubble finds the proof that the universe is expanding.
 * 7- Penzias and Wilson discover the cosmic microwave radiation.
 * 8- Jocelyn Bell and Antony Hewish discover pulsars.
 * 9- Thomas Kibble introduces String Theory.

=__The birth of the universe, Big Bang and beyond: A video__=

=__Their contribution:__=