Echoes from the Big Bang
Of course, this attempt to explain the origin of the universe is based on an application of the laws of physics. This is normal in science: one takes the underlying laws of the universe as given. But when tangling with ultimate questions, it is only natural that we should also ask about the status of these laws. One must resist the temptation to imagine that the laws of physics, and the quantum state that represents the universe, somehow exist before the universe. They don’t -- any more than they exist north of the North Pole. In fact, the laws of physics don’t exist in space and time at all. They describe the world, they are not “in” it. However, this does not mean that the laws of physics came into existence with the universe. If they did -- if the entire package of physical universe plus laws just popped into being from nothing -- then we cannot appeal to the laws to explain the origin of the universe. So to have any chance of understanding scientifically how the universe came into existence, we have to assume that the laws have an abstract, eternal character. The alternative is to shroud the origin in mystery and give up.
It might be objected that we haven’t finished the job by baldly taking the laws of physics as given. Where did those laws come from? And why those laws rather than some other set? This is a valid objection. I have argued that we must eschew the traditional causal chain and focus instead on an explanatory chain, but inevitably we now confront the logical equivalent of the First Cause -- the beginning of the chain of explanation.
