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Hello, in the beginning, runs one secular account was the Big Bang. All matter in existence today originated around 13,000 million years ago in a phenomenally hot extraordinarily condensed

primordial atom that exploded with incredible force.

Hydrogen and helium were shot across the firmament, gravity caused the gases to condense into clouds, and in these clouds

the first stars were formed.

Then galaxies came and more galaxies in clusters onwards and outwards ever expanding.

It still expanding, runs the Orthodox account and may even be speeding up.

It's still creating new galaxies and it continues to colonise more and more infinite

space despite the fact that it's supposedly infinite itself.

The word billions dominates all discussions here. So if our

universe is expanding what's it's expanding into? If it's already

infinite how can it be getting any bigger?

And is there really only one universe?

With me to tackle some of the riddles of the universe is the Astronomer Royal, Professor Sir Martin

Reese, Royal Society Research Professor in Astronomy and Physics at Cambridge University,

and author of a new book, Our Cosmic Habitat. Also here is the independent theoretical physicist

Julian Barber recently published, he recently published a book called The End of Time

and Jina Levin advanced fellow in theoretical physics at the University of Cambridge

who's also just published a book on cosmology called How the Universe Got Its Spots.

Martin Reese, as I understand it, one of the main planks of evidence for the support of the Big Bang theory

is called Red Shift.

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