System
, The Universe
• The Milky Way is just one of 140 billion galaxies, many of which are
larger than ours.
• The Milky Way contains between 100 billion and 400 billion stars.
• The number of advanced civilisations worked out to be in the Milky
Way is somewhere in the millions.
• But the distance between any two of them is about 200 light years,
eg: light leaving one of these planets would reach the other 200 years
later.
• The number of planets in the Universe is about 10 billion trillion
(calculated by Carl Sagan).
• If we were inserted randomly into the Universe, the chances that you
would land on or near a planet is less than 1 in a billion trillion trillion
(1 followed by 33 zeros), showing how huge the universe is.
, In the Beginning
• The Big Bang event led to the formation of the Universe about 14
billion years ago, when all matter and energy were created. At that
moment, all matter was compressed into a space billions of times
smaller than a proton. Both time and space were set to zero.