To elaborate on this, let’s talk about flipped coins.
There are two ways to explain why a flipped coin landed on heads.
One is to track the entire pattern of momentum and physics interaction as the coin is thrust upwards from its starting position, tracing its interaction with the air molecules it hits as it spins, how much time it has to spin in as it flies and falls, and how things play out as it is caught or bounces to a stop. (And of course whether the person who caught it slaps it on his palm, flipping it one more time in the process.)
The other way is to say that it had a 1 in 2 chance of happening, which wasn’t 0 in 2, and so this particular outcome (heads) just happens to be the one that occurred.
Both explanations are valid, but one is a lot harder and requires a lot more difficult-to-acquire data.
The same thing goes with how earth ended up in its orbit. One could explain the entire series of physical interactions that led to this chunk of rock ending up where it did, or you can just note that it was possible, and it happened. I happen to be lazy, and thus: “Why not?”
That answer won’t impress anyone who is looking for the more physics-based answer, of course.
Relating this back to the why the universe exists, we can also just answer “why not?” - and there are, of course, people who that won’t impress. But lacking any way to get a look at that extra data, there’s not much more that we can infer merely from the fact we exist.
We know that universes that exist are possible.
We don’t know whether nothingness is possible or not.
No, there’s no error and the anthropic principle doesn’t claim that. What it claims is that because we exist, we – and all creatures like us – will always necessarily observe certain particulars in the universe or, analogously, observe certain environmental conditions on our planet, because those particulars are prerequisites to our existence. It’s an important philosophical (not necessarily scientific) point, because it’s the only possible answer to questions like why is there something rather than nothing, or why are physical constants such that primordial hydrogen coalesced into stars and ignited in nuclear fusion, when there are so many different ways it might have been otherwise?
There are versions of the strong anthropic principle that posit a different kind of causation, that a universe constituted in a certain way is bound, over time, to develop intelligent life that will observe it. This is analogous to the belief that an earth-like planet with liquid water and hospitable temperatures will inevitably develop life. These are controversial and obviously debatable, but the “weak” more general version of the principle above is not.
And you lose me the second you claim that it’s actually an answer to anything. In my opinion the anthropic principle tells us exactly two things - because we happen to exist in X environment, that proves that X environment is at least slightly amenable to our existence - and that at least one such environment exists - the one we’re standing in.
Regarding the universe, I think we all figured out the universe 1) exists and 2) is at least slightly survivable (in places) long before anybody thought up the anthropic principle.
Yeah, this version is a stretch - but a least it’s attempting to say something informative or predictive about the universe. The weak version isn’t so bold.
I’m not following your objection. Any variant of the anthropic principle admits the possibility that there may be an infinity of universes, but only those with certain physical laws and constituents will harbor life – or in some versions, must harbor life. As a philosophical construct, the AP doesn’t presume to tell us how any of them came about. For that we have various metaphysical explanations and speculative mathematical models like the Hartle-Hawking state.
If you remove the requirement for intelligent and anthropic portions and substitute causation with a term like effectuation it is far less controversial.
If entropy is viewed in the slightly more correct analogy as being an increase in information, or one considers Gibbs free energy life would be highly likely to develop in any universe that can support it.
The hypothesis that it happens to create an observer is just pure casuistry.
A similar question is why humans exist. We can trace human evolution pretty well, which explains how, but not why. If you believe that god was involved you can say that god invisibly steered evolution to create us. Otherwise, there is no why. We ask the question because we evolved to ask the question, and we’d do so if we were rodent-descended rather than primate descended.
We don’t know the how of universe creation, but is the answer to why really all that different from the human case?
In my experience, non-theists with a sciencey bent tend to interpret the question “why” as actually being the question “how”.
“Why did that apple fall?”
“Because gravity pulled it towards the nearest huge mass - the earth.”
That’s actually an explanation of the mechanism at work - the ‘how’.
Part of being a materialist is recognizing that mechanisms are causes. Part of being a hardcore materialist is recognizing that human cognition, with all its deliberate intents, is just another series of mechanisms.
And the thread-related upshot of all this is, when asked “why did the big bang happen, triggering the existence of the universe?”, the sciencey answer is generally “we can’t see the mechanisms, so we don’t know.” Followed by a shrug, since what else are you supposed to do when there’s no obvious way to start looking for that data?
Ooh ooh! I actually have a different answer: there is something rather than nothing because nothing is improbable.
Of the set of all possible universes there are an infinite (or at least unimaginably vast number) containing every possible configuration of something. But there is precisely one member of the set of all possible universes that contains nothing at all. Thus, it is extremely unlikely (perhaps even infinitely unlikely) to end up with an empty universe.
Of course, the specific universe we happen to be in was equally unlikely but what can you do?
I like this explanation as it also happens to explain why your headphones are always tangled when you pull them out of your pocket.
Superficially, yes, but you have to give those who understand that why is not how enough credit. Theistic evolutionists and many deists accept the how that science has provided just fine, but are unsatisfied with the “why” part of it. A universe where these things just happened, with no why, seems spiritually empty to them.
Doesn’t bother me since I don’t have a drop of spirituality, but I think a lot of them are deeper thinkers than you give them credit for.
Yes, but that’s what I’m saying: while anthropic reasoning can explain the apparent fine-tuning of our universe to life, if one is prepared to accept the ontological baggage of an infinite multiverse, it can’t explain why the universe exists (it at best replaces that question with the larger one of why the multiverse exists). But this is the question of this thread, so the anthropic principle simply isn’t relevant here.
So when you say
then that’s just wrong, and seems actually to go against what you said in the other bit I quoted.
Why/how anything exists at all a valid philosophical question that can’t be answered right now.
It’s both the most wonderful and the most maddening thing to come to terms with reality IMO.
All the standard answers given in this thread don’t work. The Anthropic principle for example is nothing but a handwave in this context. We might reply to the question “If the universe didn’t exist, you wouldn’t be here to ask the question” with “Well it’s a good thing I am here to ask it. So…what’s the answer?”
It appears I’m the only Tegmark fan here. Let me try to expound. This is my argument, not Tegmark’s.
Imagine a real Universe like ours, in which there are creatures who appear to be conscious. Then they really are conscious. Cogito ergo sum, if you will. Or “If it walks like a duck and quacks like a duck…”
Imagine the “paper design” of a universe like ours. Within the paper design there are creatures just like us. Within that paper design, those creatures “think they are conscious.” So they are! Cogito ergo sum.
Now suppose that that paper design doesn’t exist on any paper. It still “exists” though, if only in the mind of a hypothetical Being capable of comprehending all of mathematics. But no such Being or God need be postulated — mathematics is sufficient unto itself. (The Monster Group “exists” whether or not one finds it in nature.)
Consider a hypothetical universe similar to ours, but with a fine structure constant of 137.036000 instead of 137.035999. If its axioms are consistent, it is as real as any paper design. Creatures who think they are conscious in that paper universe are conscious.
Cogito ergo sum.
Quod erat demonstrandum.
Consider a “universe” as a set including all its physical attributes, laws and other properties as elements. A “nothing” universe is the empty set. Since all empty sets are identical to each other, there is only one “nothing” universe. The set of all possible universes (actually, probably the proper class of all universes) should be infinite. The probability of selecting the one nothing universe out of infinite possible universes is zero. Therefore the universe must not be empty QED.
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Just to clarify, many of you are answering the question ‘Why (or how if you prefer that particular adverb) this universe exists?’ and a few of you might be answering ‘Why this particular universe exists in just the way it does?’ Those are interesting questions, but much more trivial. The question is not about this specific universe, but rather that which is outside or not of this universe. Why (or how) is there this extraphysical ‘whatever it may be’ and why is it there instead of not there? ‘Not there’ seems to me to be a default position. Most things are ‘not there.’ ‘There’ seems to be a special thing and a rarer thing. We can theoretically conceive of many more things than those which actually exist, the default on existence seems to be ‘not existent.’ It seems to require very special conditions to be met for something to exist. So assuming that there is something ‘extrauniversal,’ why does this extrauniversal thing exist?
