Original Link : https://wmbriggs.com/post/27719/
The biggest question that we’re even capable of asking, with our present knowledge and understanding of the Universe, is where did everything we can observe come from? If it came from some sort of pre-existing state, we’ll want to know exactly what that state was like and how our Universe came from it. If it emerged out of nothingness, we’d want to know how we went from nothing to the entire Universe, and what if anything caused it.
A pre-existing state is not nothing. It is something. And therefore had to be itself created. It had to have a reason for its existence, an explanation. It can not have come from nothing. For nothing cannot create anything.
Anyway, we’ll call the universe all there is. All there is would include that so-called pre-existing state. So we’re back to the original question: Can We Really Get A Universe From Nothing?
The answer is no.
Is an electron nothing? No, it is something. Is gravity nothing? No, it is something.
Well, how about a quark? Is that nothing? No, it is something.
Quarks are big, electrons are huge, and gravity needs stuff, all of which are somethings. And somethings aren’t nothing. So how about a quantum fluctuation? That’s pretty darn small! Is that nothing?
No, it is something. It is a fluctuation of some thing, and a some thing is not nothing. It is something.
But if we graciously allow that something is nothing, in the same sort of way every child wins a trophy for participation, than we can say a universe can come from nothing.
And if we can say that the universe can come from nothing, then we have solved one of the oldest philosophical problems there is. Even better, we have eliminated the need for God to create the universe from nothing, because we have our own official version of nothing, namely very small somethings, from which, physicists say, the universe can come from.
All it took was a little redefinition of words. Not bad for ten minute’s work!
Don’t scoff, because we’re not the first to think of it.
You might be wondering why it’s important to think about these concerns when talking about a Universe from nothing. After all, if your Universe is full of matter and energy, it’s pretty hard to understand how that’s relevant to making sense of the concept of something coming from nothing. But just as our intuition can lead us astray when thinking about matter and energy on the spacetime playing field of General Relativity, it’s a comparable situation when we think about nothingness.
A universe full of matter and energy is not a universe full of nothing. It is full of something and came from something.
You very likely think about nothingness as a philosopher would: the complete absence of everything. Zero matter, zero energy, an absolutely zero value for all the quantum fields in the Universe, etc. You think of space that’s completely flat, with nothing around to cause its curvature anywhere.
If you think this way, you’re not alone: there are many different ways to conceive of “nothing.” You might even be tempted to take away space, time, and the laws of physics themselves, too. The problem, if you start doing that, is that you lose your ability to predict anything at all. The type of nothingness you’re thinking about, in this context, is what we call unphysical.
If we want to think about nothing in a physical sense, you have to keep certain things. You need spacetime and the laws of physics, for example; you cannot have a Universe without them.
Of course, thinking about creating a universe from nothing is not to think in a physical sense at all. Siegel admits this in the link, in the fourth meaning of “nothing” (the first three are all very definition somethings).
But in the context of physics, we cannot make sense of this sort of nothingness. We’d have to assume that there is such a thing as a state outside of space and time, where you can have the emergence of spacetime from this hypothesized state of true nothingness.
Siegel says that in order to solve the problem, it has to be put in physical terms; if it is not in physical terms, physicists can’t solve it; since physicists have to solve it, it has to be in physical terms. And so somethings are defined as nothing.
This is cheating.