Page 71 - The Origin of Life and the Universe - International Conference 2016

The Origin of Life and the Universe

passage to expel the waste, in two dimensions such passages would cut the
animal in half. Now you might say well, you know maybe the food came
back out the same way, but it misses the key point. In two dimensions
there are not enough connections to be made for the complexity that life
requires. It's not just about whether the food has to come out the same
way it came in. It's actually far more fundamental.
So perhaps if one or two dimensions is too simple maybe if we had
more spatial dimensions. That's better, would that adds to the complexity?
And it turns out that that's not correct. If you go to four or five or more di-
mensions, it turns out that there are no stable orbits. Now this means two
things, with more spatial dimensions, atoms are not stable. So the carbon
and the nitrogen and the oxygen in the life requires wouldn't exist. And
planets are not stable they cannot form stable orbits around stars, they
either spiral very rapidly into the star or they spiral away from the star.
And so you miss two of the key requirements for life if you have more
than three spatial dimensions. You don't have the atoms that life requires
and you don't have the planets that life requires.
Changing the number of time dimensions makes things even worse.
Now, so if you look at this diagram here just as you change, the number of
time dimensions you get into a lot of these places where physics is unpre-
dictable. Now you may say, well I don't know how to do physics why is it
necessary for it to be predictable? Again it turns out to be a more
foundational principle than that. Because if physics isn’t predictable what
that means is that measurements of what goes on right now, tell you
nothing about what's happened in the past and will give you no insight as
to what will go on in the future. So organisms that sense the environment
and say there's food there and there's danger there, if physics is unpredictable,
that's impossible. And so again the key features that life requires do not
exist in any kind of universe except for a universe with three large spatial
dimensions, and one time dimension.
So now let's turn our attention to the laws of physics. Particularly let's
look at how carbon, oxygen and nitrogen exist in the universe. To do that
we got a look a little bit about how the universe has developed over time.
So in Big Bang cosmology, after the first few minutes the only elements

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