Impossible to cite but presumably the current universe existed before any intelligence was around to ask the question.
Sure. If all that exists, aka the universe, is expanding, and it is surrounded by nothing then there must be more nothing ;). As pointed out by others, our language can’t cope with these concepts.
As far as I know, there’s nothing in the BB theory that precludes an infinite universe. Cosmologists bring up the possibility of it being infinite, but say there’s no way to determine whether it is or not.
As for speed of recession, that’s a function of distance (the Hubble Law) and there’s no limit on how fast two parts of space are receding from each other. Perhaps a better way of putting it than “moving faster than light” is to say they are outside each other’s event horizon (or Hubble horizon, as it’s sometimes called), so the two sections can have no influence on each other.
I was fully expecting this to be about the somewhat more prosaic question related to the not quite balance of matter and anti-matter in the primordial universe. (How come it didn’t all cancel out instead of almost cancel out?) Often the cutesy title of some of these conversation is something like “Why is there anything?”
Why questions often confuse me anyway when I’m not sure if the question is “By what means?” or “To what purpose/end?”
I hate to break it to you guys, but I’m crazy, and you’re all just figments of my imagination. Don’t get too hung up on yourselves, OK?
So it’s you!
Couldn’t you have imagined us a bit, y’know, cooler or something man? Like with superpowers or something?
And why did I never get that promotion? Or a second date with Sandra? Not cool bro, not cool.
You need to up your imagining game.
Once you start putting descriptors to it – calling it a “reality,” wanting it to be “meaningful,” or making it “imaginable” – then, sure, a total absence of anything is not any of those things.
And yet… It could have happened. “Nothing” might have been the fact of the cosmos. There is no reason that “things” had to exist.
Such a void would not be a “reality,” but simply the absolute absence.
(I invoke a variation of the anthropic principle, simply to note that such a void isn’t the case…because if it were, we wouldn’t be here to observe it. The anthropic principle has always sailed close to the winds of tautology.)
The last part is not quite right, which I say not to be pedantic, but because it leads to something rather cool. Because the expansion of the universe is not constant, the Hubble Sphere moves through space. So although the Hubble Sphere marks the boundary of superluminal recession at any point in time, it is not an event horizon, it does not delineate the boundary of the observable universe.
So here’s the cool thing. Any photons that we now see that were emitted in the first 5 billion years of the universe were from galaxies that were outside our Hubble Sphere, i.e. receding from us faster than light. So these photons set moving towards us through local space at the speed of light, but the expansion of space meant that their initial net motion was away from us. Our expanding Hubble Sphere eventually overtook the photons, and they started moving towards us, reaching us billions of years later. However, our Hubble Sphere never overtook the galaxies that they came from. So we are seeing galaxies that have always been receding from us faster than light!
Source:
Expanding Confusion: Common misconceptions of cosmological horizons
and the superluminal expansion of the universe. Davis & Lineweaver, 2003.
https://arxiv.org/pdf/astro-ph/0310808.pdf
The above paper is really excellent, and quite accessible without any heavy math. So far as I know, nothing in it is out of date, but I’m not an expert.
I disagree. As Trinopus just explained, nobody is talking about a “nothing” that is a discrete kind of reality, and making the positive claim that it could exist.
“Why is there something rather than nothing?” is just asking “Why p and not ~p?” using the imprecise English language. I don’t see that as a word game.
Some of your misconceptions about the Big Bang Theory have been covered by others, but let me cover another one.
The size of the universe that is often described in the Big Bang Theory is the size of our observable universe, not the entire universe. And when discussing that size through time, it is describing the size of just our observable universe as you go back in time, shrinking in size from billions of lightyears across to something unbelievably small. But, even at that time a fraction of a second after the Big Bang, when our observable universe was incredibly tiny, the entire universe may have extended to a vast size. Who knows whether “infinite size” is a meaningful notion, but we can’t say anything about exactly what lies outside of our observable universe. And the Big Bang Theory does not address this. The Big Bang Theory does not say that the universe originated at a “point”. The Big Bang process happened everywhere.
Trinopus, claims not to be talking about a discrete reality and then immediately describes this nothing as a void.
I understand that you disagree, but I don’t think you’ve really explained why.
Like I said before, there is nothing in Narnia. If your nothing really is nothing, if it has no temporal or spacial location, how is it different from Narnia? Is it any more real?
I don’t see how you’re justifying that assertion. When could it have happened? What cosmos?
You said that the original question “Why is there something rather than nothing” is a word game. I said I disagree, that that question means “Why p and not ~p” rather than making a positive assertion of a “no-thing” existing.
I’m recapping what I said because I can’t think of a clearer way to put it.
Let me try a different approach.
Imagine someone hands you a Book of Perfect Knowledge.
Are you really comfortable with the opening lines being:
In the beginning, there were logical constraints.
And so there just was a universe. Because, think about it, we can’t really conceive of a nothing existing, right? So, there had to be something, by force of logic. And that something happened to be space-time mass-energy
Not only are you comfortable with these lines, you think any discussion trying to go beyond that is inherently silly?
NB: I’m an atheist; I’m not trying to imply the Bible is an example of a “good” Book of Knowledge. It’s bollocks.
When we speak of “something”, what we may mean is the set of physical laws that specify the universe. I think the criticism of Krauss is best framed in these terms. Krauss is attempting to explaining to explain one set of physical laws by invoking some other deeper set of physical laws. But that approach is just “turtles all the way down”. He has not addressed the metaphysical question of how it came to be that any physical laws exist.
That metaphysical question is unscientific, and perhaps nobody can meaningfully answer it. But I don’t think you have made a good case for the question being meaningless or incoherent.
Well if I knew it to be a book of perfect knowledge, I guess I’d have no choice but to be comfortable with what it said. Leaving that aside, the origin story here wouldn’t represent the only possible alternative to a state of absolute nothing. It could be that the observable universe was preceded by another type of universe, or that there was infinite empty space before the big bang. Maybe if you traveled back in time towards the big bang, the geometry of space-time would be such as to never allow you to reach T=0 and so the universe is boundless in time as well as space. I don’t think any discussion beyond this is inherently silly. Heck maybe the universe even sprang from a logical impossibility. It seems bold to assert that it did without justification though.
If the hypothetical book of perfect knowledge opened by saying “There was always something”, not only would I be comfortable with it, I would think it was tautological. If on the other hand it contained the sentence “There was nothing”, I would have no idea what it could possibly mean.
So again, there are no laws, apart from the law of “something never comes from nothing?”
How did we determine this law to be so much more fundamental than all other physical laws?
I have no idea what you’re talking about. That does not follow from what I said at all.
If you have no idea what I’m talking about, then how do you know whether or not it follows?
The question of how any laws arose in a particular region is perfectly coherent to me. The question of how they arose never and nowhere is not.
It’s always something. If it ain’t one thing, it’s another. (more words from a great philiosopher)
You’d have no choice but to believe what it is saying is true, but that’s not quite the same thing.
Personally that answer seems incomplete to me, so if I believe the book has perfect knowledge I guess I’d have to come to the conclusion that a full description is unknowable.
Nor do I. However the “something from nothing” question, being a metaphysical question, I think is intended to be at the top level. So saying our universe bubbled up from a multiverse is no more ultimate an answer than saying our solar system coalesced from some of the remains of a blue giant star.
Ah but here’s the thing: ISTM equally bold to say it sprang from there being only one logical possibility. That there “just had to be” something, and reality somehow knew what something to be.