Recipe for the Universe - Just Six Numbers

It is astonishing that an expanding universe, whose starting point is so 'simple' that it can be specified by just a few numbers, can evolve (if these numbers are suitable tuned) into our intricately structured cosmos.

= 0.007 Another number, epsilon, defines how firmly atomic nuclei bind together and how all the atoms on Earth were made. The value of epsilon controls the power from the Sun and, more sensitively, how stars transmute hydrogen into all the atoms of the periodic table. Carbon and oxygen are common, and gold and uranium are rare, because of what happens in the stars. If epsilon were 0.006 or 0.008, we could not exist.

Perhaps there are some connections between these numbers. At the moment, however, we cannot predict any one of them from the values of the others. Nor do we know whether some 'theory of everything' will eventually yield a formula that interrelates them, or that specifies them uniquely. I have highlighted these six because each plays a crucial and dis-tinctive role in our Universe, and together they determine how the Universe evolves and what its internal potentialities are; moreover, three of them (those that pertain to the large-scale Universe) are only now being measured with any precision.

Why the Universe is so large

The tremendous timespans involved in biological evolution offer a new perspective on the question 'why is our Universe so big?' The emergence of human life here on Earth has taken 4.5 billion years. Even before our Sun and its planets could form, earlier stars must have transmuted pristine hydrogen into carbon, oxygen and the other atoms of the periodic table. This has taken about ten billion years. The size of the observable Universe is, roughly, the distance travelled by light since the Big Bang, and so the present visible Universe must be around ten billion light-years across.