Review of 'The Grand Design' by Stephen Hawking and Leonard Mlodinow - part 2: a universe that creates itself out of nothing
This is the second part of a review of 'The Grand Design,' by Stephen Hawking and Leonard Mlodinow. This page looks particularly at the claim that the universe can create itself from nothing.
'The universe creates itself out of nothing.'
Don't laugh. No, seriously, don't laugh. Hawking and Mlodinow are putting this forward as an argument for not believing in God. Their basic argument is that there must be a law of gravity. The law of gravity must take a particular form (one involving negative energy). Because there must be such a law, the universe created itself out of nothing:
'Because there is a law like gravity, the universe can and will create itself from nothing. (Page 180)
'We've seen that there must be a law like gravity, and we saw in chapter 5 that for a theory of gravity to predict finite quantities, the theory must have supersymmetry between the forces of nature and the matter on which they act. M-theory is the most general supersymmetric theory of gravity. For these reasons M-theory is the only candidate for a complete theory of the universe. If it is finite - and this has yet to be proved - it will be a model of a universe that creates itself. We must be part of this universe, because there is no other consistent model.' (Page 181)
We'll talk about M-theory later. For the moment, let's just focus on the big idea: a universe that creates itself out of nothing, because a particular kind of law of gravity must exist - and because of this, there is no need for God:
'Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.' (Page 180)
These are serious scientists, putting forward serious ideas. So what is wrong with them?
Nothing comes from nothing
Hawking and Mlodinow's idea of nothing isn't really nothing. It includes at least a law of gravity. So they are smuggling something into their idea of 'nothing.' They aren't really starting with nothing at all - with nothing nothing, as we might say. And this is cheating. Where did this law of gravity come from?
They say that such a law must exist. No, it mustn't. Really mustn't. If there is nothing, there is nothing. including no scientific laws.
And if there is nothing, that nothing cannot do something. It cannot create itself, or anything else. Philosophers have understood for centuries that nothing comes from nothing. Hawking and Mlodinow would like to reverse this.
Laws don't do anything
They try to do this by giving to scientific laws an almost magical ability to do something. But laws themselves don't do anything at all. All they do is describe what happens under particular circumstances:
'Laws themselves do not create anything, they are merely a description of what happens under certain conditions.' (Professor John Lennox)
This is really important. A scientific law never made anything happen. All it does is describe what happens. Gravity causes planets to stay in orbit and apples to fall. The law of gravity doesn't. The law just describes how gravity works.
And scientific laws need something to work on - they have to describe something. If there is nothing, then there is no gravity, and no law of gravity. Here's John Lennox again:
Isaac Newton's laws of motion in themselves never sent a snooker ball racing across the green baize. That can only be done by people using a snooker cue and the actions of their own arms.
Hawking himself recognised this earlier when he asked 'what is it that breathes fire into the equations and makes a universe for them to describe?' ('A Brief History of Time,' page 184.) Now, he seems to have decided that the equations can breathe fire into themselves.
Causation or energy
Hawking and Mlodinow say that any universe that could ever possibly exist must have a law of gravity, in order to balance the energy budget. So they say:
'Bodies such as stars or black holes cannot just appear out of nothing. But a whole universe can. (Page 180)
The physics behind their claim is the idea that the total energy budget of the universe is zero, because gravitational energy is always negative. (Weird as this may seem, it is true. That's why it takes a rocket to launch a satellite into space - you have to add energy to separate two objects that are held together by gravity.)
But they've made what seems to be an elementary mistake, of saying that because the energy budget can be balanced, the universe must exist. They've mistaken the energy budget for a mechanism that can cause the universe to come to exist. It isn't. It may well be that any universe that actually exists must have a balanced energy budget - but this doesn't explain what causes the universe to exist in the first place.
If a believer in God had put forward this kind of argument for believing in a creator, we would have been laughed out of town for it. And we would have deserved it.
More reactions to 'The Grand Design.'
And an interesting video response...