The notion ‘something cannot come from nothing’ is a common one in science and philosophy. Some believers use it to object to atheists, arguing that the universe must have had a creator. So let us answer this on three levels: first, the religious, then the philosophical, then the scientific.
Let us suppose that nothing really can come from nothing. If nothing can come from nothing, then where did god come from? If he ‘always was,’ then the universe could have ‘always been.’ Now, the universe ‘originated’ in the big bang in the form we know it today, but who is to say what came before? We don’t know what there was before, but that doesn’t mean it came from nothing. It just means we don’t know from what it came. We cannot say ‘therefore it was the personal god described by the torah/bible/quran.’ Nor can we say ‘it was the gods described by the hindus!’ Nor can we say ‘it was Ymir like the Norse said!’ No, we can’t say.
And, if god can be a ‘First Cause,’ then why can’t the Big Bang be a first cause? Maybe the Big Bang is the first cause, but this first cause is not a personal god/Abrahamic god, etc.
In philosophy, this notion is often called the principle of sufficient reason. Schopenhauer won a prize for writing an essay on this topic. But is it really philosophical? No. There is nothing contradictory about the notion of something coming from nothing, or of something being a ‘first cause,’ with nothing to precede it causally (remember, chronological ordering may not even apply outside our physical universe, but causal ordering does). And as Hume pointed out, the only things which are truly impossible, are those which are contradictory.
In fact, the notion ghat nothing can come from nothing is a bit wrong. We can create matter out of light, for example. But in each case, we are changing one form of energy into another. So, scientifically, nothing comes from nothing, and energy is conserved, right?
Well, let’s back up a moment. Yes, those are the laws of science which we observe. However, these are a consequence of the symmetry we observe. Let us look at what this symmetry entails. There are actually many forms of scientific symmetry, and each has its own consequences. This is because of Nother’s theorem, which states that every symmetry in physics gives rise to a conserved quantity. Now, one thing in physics is that it does not change over time. And this gives rise to the conserved quantity we call energy. But that might not apply before the big bang! (The fact that physics looks the same in one place as another gives rise to the conserved quantity of momentum; other symmetries give rise to other conserved quantities).
To put it another way, we cannot know what laws hold outside our universe. Maybe in some meta-ultra-verse, there are other universes with other physical laws, and maybe in the meta-ultra-verse, new universes can start (this seems like the most reasonable assumption to me for unrelated reasons). Or maybe, our universe started along with a paired universe whose energy is negative, so that there is a total of zero energy. Who knows? In fact, in general relativity, the entire notion of energy is very hard to pin down for technical reasons; conservation of energy may need to be replaced by a more precise concept.
A final note on the religious point:
And of course, according to religion, god created the universe from nothing. so apparently, this god could defy conservation of energy (unless he created it from himself, in which case, what made him, and why would this argument not justify the universe being made of something else that was pre-existent?)! Which means that one way or the other, both the religious and the atheists say: ‘Something came about, possibly from something prior to it, and possibly created out of nothing. Maybe it was created, from something already extant or out of nothing, by a god about whom we claim to know something, or maybe it came about due to some mechanism we claim to know nothing about.’ Now, the latter seems much less of an assumption than the former, does it not? In other words, the burden of proof is on the theist here, to prove that their god is the origin/creator of the universe.
In other words: okay, something ‘gave rise’ to the universe – prove it was your god!
Either there was a first cause or not. If there was, there’s nothing about this fact to tell us anything more about the first cause. If not, there’s still nothing to tell us what happened causally prior to the start of our universe. In either case, ‘we don’t know without more evidence’ is surely the more intellectually honest option than assuming it must have been the god of some specific religion, or asserting that it must have had additional properties.
I would suggest that the spontaneous creation of universes is possible in some metaverse, each universe having potentially different laws of physics – and that life can only really exist in an orderly universe which would have many conservation laws, for example, the conservation of energy that we observe. But this is just my take on it. Regardless of the truth, I would need more evidence to conclude that there is a personal creator of the universe!