You have to be careful when you’re describing something you probably don’t understand properly, particularly when it’s Stephen Hawking’s explanation of how the universe began. But his performance on SBS last night so beautifully lucid that I am tempted to try.
The universe is full of large black holes whose gravitational force sucks in matter (mainly hydrogen and helium) and compresses it until the temperature rises to billions of degrees.
At this point, and here I am skating on thin ice, matter no longer exists at the atomic level but at the subatomic level, namely as pure energy in the form of protons, electrons and neutrons. Eventually, the contents of the black hole explode and form a supernova.
In this explosion, new matter is formed from the subatomic particles: namely carbon, hydrogen and iron. These are the basic building blocks for the new galaxies which form around stars, such as our sun, that consist primarily of the hydrogen and helium from the supernova.
Eventuall, over billions of years, the stars created by the Supanova burn out and collapse into black holes starting the process again.
So, time is circular, there was no beginning, there is no end. It’s a cycle of creation and decay, on a cosmic scale.