Ignoring the obvious questions, "How can you get a god from nothing, and what did it make everything out of when there was nothing to make it from?" creationists settle for the most infantile of all 'answers', "It must have been magic!". And of course it goes without saying that there must have been a magic man to do the magicking and that magic man must have been the locally popular one that mummy and daddy told them about.
This comes from the arrogant assumption that the Universe should be easy to understand without needing to learn anything and from the resulting ignorance about the nature of the Universe and in particular that the Universe is actually made not of 'stuff' but of energy. 'Stuff' is made of energy, as Einstein showed. Everyone can quote Einstein's e = mc2 and yet creationists in particular seem incapable of understanding what it means.
e = mc2 is the relationship between energy and matter and shows how they are the same thing. In fact, it shows that matter is simply a form of energy. 'c' being the velocity of light, which is very large, means that it takes lots of energy to make a small amount of matter and a little bit of matter contains lots of energy. Basically, that's why atom bombs are powerful.
So where did all this energy come from and why does it show how you get a Universe from nothing?
Well, the Universe appears to be made of four fundamental forms of energy which manifest as four basic forces:
- The Strong Force - which can hold a nucleus together against the enormous forces of repulsion of the protons.
- The Electromagnetic Force - manifests itself through the forces between charges and the magnetic force. Fundamentally, both magnetic and electric forces are manifestations of an exchange force involving the exchange of photons.
- The Weak Force - a force involving exchange of elementary particles in the atomic nucleus.
- Gravity - an attractive force proportional to the mass of an object.
Gravity is actually a very weak force but it acts over a theoretically infinite distance. Consider Newton's apocryphal apple clinging to it tree by the nuclear forces holding the molecules of its slender stalk together and yet able to resist the entire gravitational force exerted by Earth. Yet everything that has mass has gravity so the sum total of the Universe is, well, massive.
One explanation for what happened in the initial 10-43 seconds is that a quantum fluctuation large enough for relatively weak gravity to become stripped away from the other three forces and 10-43 seconds was enough for this to cause a hyperinflation in which almost unlimited positive and negative energy could be created but always totalling zero. This Plank Time is the minimum time that can exist so the instant the Universe came into existence, it was immediately 1*10-43 seconds old.
The sum total of all the energy in the Universe is zero.
The Universe is literally nothing. Not something, but nothing has come from nothing!
It's a bit like borrowing from a bank. The Bank lends you $1000. You now have $1000; the Bank has -$1000. You both have an asset which you can use (the Bank can actually sell your debt as an asset because it represents a bit of your future earning that the bank now owns and you can use the $1000 for whatever you borrowed it for) and yet no wealth was created by that transaction.
What followed after this initial 10-43 seconds is now very well understood and can be read in the first part of my blog, What Makes You So Special?
So when creationists ask how the Universe came from nothing, all they do is betray the ignorance upon which their superstition depends. That they are primed to ask these sorts of questions by the pseudo-scientists who feed them this ignorance in return for money speaks not so much of their credulous gullibility as of the criminal dishonesty of those cheats who sell them the stuff.