Nothing doesn’t happen.
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Don’t know where you learned that but you should probably get your money back. They wouldn’t be theories if they didn’t have a theoretical basis.
Many worlds interpretation of QM is indeed mathematically rigorous. Bubble universe theories are still being worked out but so far seem mathematically plausible.
As far as testability goes, you don’t actually have to visit another universe to test these theories as long as the theories have implications about what we’d expect to see in our own universe. They’re like any other theories in this respect. If they make predictions they can be tested; if not, they can’t.
As far as whether QM or relativity predicts these things…well, many worlds interpretation of QM is increasingly popular among theoretical physicists for a number of reasons. But more importantly, QM and relativity are demonstrably incomplete and the whole point of the multiverse theories is to try to reconcile those two theories.
So, what separates multiverse theories from creationism?
Multiverse theories are, at the very least, consistent with what we have already empirically determined about our universe. Creationism is demonstrably not consistent with what we have already empirically determined about our universe.
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Well, a “theory” is just an idea. There is a difference between the flat-earth theory and the theory of relativity, but they are BOTH just theories. It is just that one is obviously false, and one had been proven true to a high degree of accuracy. But relativity is not actual FACT, because is breaks down at small scales (incompatible with quantum theory). it is just a very good approximation under certain conditions. Even if we happen to find a true Grand Unified Theory, that will still be a theory because there might conceivably be conditions under which it is false.
Note that there are varying degrees of right (this logic stolen from Isaac Asimov). The Earth is flat. Is this true? Actually, yes. At small scales, the earth is flat. My yard is relatively flat. However, this approximation starts to break down on a scale of dozens of miles. So, next, we concluded that the earth is a sphere. Is this correct? Why YES, the Earth is a sphere! This theory works… whoops. The Earth is NOT a sphere. It is actually somewhat egg-shaped. The deviation from a sphere is tiny and hard to measure, but it is there.
Similarly, Newton’s gravitation laws are true – under ordinary circumstances. They fall apart at high speed or high mass, so relativity actually improves Newton’s laws. Newton was still correct, but Einstein was correct for more circumstances.
This is the way that theories work. You never assume that they are fact – you just get increasing confidence that they predict reality. But, if they predict something wrong, it is time to find something that works better.
Now, if a theory makes not actual predictions, then you have NO way to gain any confidence in it. For a theory to work, it had to predict something that other theories cannot.
Well, not really, The math behind quantum theory, in essence, says: “if you do this, you will get that result.” Or, at least probabilities of certain results. It says absolutely NOTHING about the deep meaning behind the observations. For the famous double-slit experiment, quantum theory predicts what the result is. However, where is the photon BEFORE you measure it? Is the photon some sort of “probability wave” moving through one universe, or this the result the superposition of all possible photons in an infinite number of universes? AFAIK, the math is silent about that. Note that the Copenhagen interpretation is called an “interpretation” and not the Copenhagen “theory.” Why? Because the interpretation does not make any new predictions, but is instead a mental model to help scientists get their heads around the theory. There may be other interpretations that work just as well. And until it makes a prediction and therefore turns into a “theory,” you will just have to take an interpretation on faith.
Well, until somebody comes up with something testable, there is no proof that bifurcating universes actually happens. It is ONE interpretation of quantum theory, but not the only one. I have a theory that the entire universe was sneezed out of the nose of the Great Green Arkleseizure. Of course, it is not testable (at least until the coming of “The Great White Handkerchief”), so you will just have to trust me that it is true.
Huh? I must admit ignorance here. I have read a little about multiverse theories, but using them to unify quantum and relativity was never one of the justifications, as far as I can recall…
Really? Science has proven that all effects have a cause. Having a creator of some kind has not exactly been completely disproved. It is certainly the trend right now, but I am also aware of something called “confirmation bias.”
To be honest, I used to imagine that the big bang would eventually be followed by a big crunch, which would rebound to another big bang. That model is simple, elegant, and could explain so much, since there would be, in theory an infinite number of universes – like an infinitely long string of pearls. The cause for the creation of the universe is simply the end of the previous universe…
With inflationary theory, there will apparently be no big crunch, so the question of the origin of the universe is rather less settled at this point. Honestly, having a creator makes as much sense, and is currently just as testable, as the rest of the theories. If you discount a creator, it is because you believe that there is no creator “a priori”. If you do believe in a creator, then believing that a creator made the universe seems possible.
If your concern is that everything should have a cause, supposing a creator also doesn’t help one iota. So it’s not so much a matter of discounting that a priori as recognizing it isn’t a solution, just another question.
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Well, the decay if uranium atoms just does not happen. It does have a REASON. The nucleus is unstable (lots of math involved that I don’t understand – Radioactive decay - Wikipedia). However, the math IS understood by somebody. The only thing that is NOT known is when a particular atom will delay.
Think of it as taking 20 6-sided die and rolling them until you get all sixes. Do this 1000 times. Math can predict how likely you are to get all sixes on any particular roll and, on average, how long it will take. You cannot predict what each particular roll will be. There is absolutely no mystery in the process (unless you have a lot of money riding on the result), and it does not “just happen.”
That’s the every-day understanding of it, but that’s not true of scientific theories.
Only in the sense that there are no such things as facts at all. At some point you’ve got to cut short the infinite regress and say “OK, I’m willing to accept this theory as a fact.” Also, relativity is not incompatible with quantum theory. Models of the electron, for example, have to take into account relativistic effects. They don’t cohere very well – neither is predicted by the other – but they’re compatible in that they don’t actually contradict each other.
I’ve spent quite a bit of time studying philosophy of science, I didn’t need the layman’s recap. Unfortunately, you do have to assume theories are fact pretty much all the time to avoid infinite regress. For example, to justify the use of telescopes in astronomy you must assume your theories of optics are factual (so that you can infer that your telescopic observations are accurate to within whatever degree of error and not entirely misleading or inconsistent).
Exactly as I said.
This seems to have nothing to do with the statement to which you are responding. Many worlds interpretation is indeed mathematically rigorous. See here:
http://plato.stanford.edu/entries/qm-manyworlds/
For bubble universes, see here:
http://space.mit.edu/home/tegmark/crazy.html
Or better. The many worlds interpretation is gaining ground on Copenhagen because it works better.
I really dislike this loose use of the word “faith”. If Copenhagen interpretation sort of makes sense of QM but has to invoke some strange metaphysical notion of “observation” and many worlds makes sense of QM but does not have to invoke any strange metaphysical notions at all then one can reasonably say many worlds is a more plausible interpretation. When you say “on faith” it sounds like there is no basis for making a decision whatsoever but that is not strictly true.
If all others can be eliminated for various reasons, then it has good standing as the best interpretation around. This observation goes for theories as well. Otherwise, you could just generate as many theories as you wanted that you custom fit to the data and they would all be equally plausible. For example, I could make up relativity 2 that makes all the same predictions as relativity except for something that can’t be measured. Then I could say, just like you do, that when you accept the validity of relativity you do so on faith because there’s a perfectly good alternative: relativity 2.
Then you should read more. That is the point of pretty much any cosmological theory at this point.
Citation desperately needed. Scientific evidence suggests that many effects don’t have a cause last I checked.
And in fact cannot be unless your creator theory makes specific predictions that can be proven or disproven. Which isn’t on the agenda of most religious believers, I find.
Seems to me that would more likely be a problem for those who have an emotional attachment to the idea of a sentient overseer of the universe rather than those who are uncommitted to any such explanatory paradigms.
Forget cosmic inflation. Current empirical findings confirm that the universe is expanding faster than gravity could possibly pull it back together. To the extent that there is any such thing as a fact, the open-ended universe is a fact.
It’s only as testable as other theories if you commit to a particular set of predictions. Unfortunately for the “God” theory, God is conceived of as a sentient being with idiosyncratic and inscrutable motivations. This prevents anyone from predicting what God will do and thus prevents God-based theories from being tested.
Or it’s because of the forgoing observations coupled with the lack of any compelling reason to believe in such a thing. I’m only as skeptical of God as I am that we live in the Matrix. If you can prove to me we don’t live in the Matrix then I will seriously consider the possibility of God’s existence.
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Well, if everything that exists was created ten milliseconds ago, intact in every way, including fossils and dictionaries and all your memories of all prior experience, that would be entirely consistent with what we have already empirically determined about our universe.
It isn’t necessary to believe in something merely because you can’t empirically prove it’s wrong. I can’t prove you aren’t a figment of my imagination, but I choose to believe you aren’t.
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Do I really need to add “assuming we don’t live in the Matrix” to everything I write on the subject? Obviously Last Thursdayism can explain any empirical observations whatsoever.
We have a choice: assume nothing can actually be explained (a la Last Thursdayism) or assume that explanations are possible. If we assume the latter then I think I’m justified in making an inference to the best explanation. Which is all I’ve done here.
Edit: By “creationism” I was assuming we were referring specifically to biblical creationism because, unmodified, that is typically how “creationism” is used. If we’re just talking about the universe being created by some mysterious entity that is somehow sentient (despite the contradictions that causes when considering an entity unaffected by time or any of the usual limitations faced by sentient entities) then we could as easily be talking about deism which is not usually considered a form of creationism.
I can’t disprove deism but if you give me a few basic premises to work with I can prove the Book of Genesis is factually inaccurate
Ah, thank you for that clarification. Apologies for the pedantry!
I was just using “Last Thursdayism” as an example of something that isn’t amenable to empirical testing. I don’t think it is more or less likely than any of the multiverse theories I’ve been exposed to. Until I actually travel to a parallel universe and come back again, the multiverse is a hard sell.
If I were the creator, I’d make it so that the beings I create could never tell who my creator was.
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Well, first of all assuming Last Thursdayism isn’t different to me from assuming we’re in the Matrix. Either way, you’re basically cooking up a thought experiment in which inferences from sense experience aren’t sound.
Second of all, you’re assuming that the only salient feature of multiverse theories is that they feature inaccessible universes. This isn’t necessarily true. It’s completely possible for a multiverse theory to make predictions about this universe that may be used as evidence for or against the theory. (So the same theory without the other universes must be more plausible, right? Not necessarily, the other universes part may be required for mathematical reasons.)
So what it seems to me you’re saying is something like: “I’d just as soon assume that inferences made from our sense experience are unsound as consider an explanation that cannot be demonstrated by the brute force method.” Seems like a silly position to me but what do I know.
In other words, I’d prefer to take theories on their own terms rather than let its resemblance to ideas from science fiction dictate how plausible it seems to me.
In a sense, that is true. Newton’s theory was fact until it could not explain the orbit of Mercury, then it wasn’t. It was true, as far as it went…
The ultimate test of a theory is “does it work?” Optics have been proven to work. Does that mean that it is capable of predicting everything? What if a new phenomenon is discovered that is not predicted by optics? Does that mean that reality is wrong?
My point is just that theories are NOT facts. You can gain confidence in them, and I would say that optics, using the materials that we commonly use, and in the distance scale that we use them, has a confidence of approximately 100%. But, optics is not perfect. Take a single helium atom in free space. Helium is transparent, so should this thing act as a tiny lens? Granted, you would need a photon with a wavelength much shorter than the diameter of the atom. But, if you used a suitably-energetic photon (and it was not absorbed), optics predicts that a single atom should be able to act as the universe’s smallest spherical lens. Somehow, I doubt that this is the case (but I don’t really know for sure). That does not mean that optics is wrong, just that you can’t use it everywhere without thinking about were it has been proven to be true.
Theories are NOT reality. Theories are a MODEL of reality. The elusive goal is a single, hopefully simple, model that can explain and predict everything. The fact that we currently have to rely on two mutually-exclusive models means that neither model is actually true. They are true for their domain, but start to break down around the edges. I have a map near me. It looks like Greenland is as large as America. That is the flaw of that model – distortions are greater the further you get from the equator, and nearly useless at the poles. Similarly, in a black hole, you find that you need both relativity (extremely high gravity) and quantum (Pauli exclusion principle, perhaps) effects. So, which model is true in this case? Possibly neither.
OK. This is where I disagree with you. It seems to be taking one problem (action at a distance, randomness) and replacing it with another (multiple universes). Who defines what is “better?” The ultimate test is: does multiverse make a testable prediction that Copenhagen does not? If so, then great, let’s do the experiment (wouldn’t it then be a “theory” and not an “interpretation?”). If not, then I would consider both to just be alternate ways of looking at the same thing. As an Electrical Engineer, sometimes I find it useful to look at a signal in the time domain. Sometimes the frequency domain is a better representation for a particular problem. Neither one is more “right” than the other. Some problems which might be very difficult to solve in one domain are trivial in another. Could these different “interpretations” be something similar? Is that damned cat alive or dead? Since you cannot see the cat without looking at it, does it really matter? That is a thought experiment. If you really DID the experiment, you would see either an alive cat or a dead one, and never a superposition of the two. So, does it really matter?
OK. This I REALLY need some help with. Which effects do NOT have a cause? I really cannot think of ANY. There are processes that are random (radioactive decay being the best example). The time that a particular atom will decay is random, but the reason for the nucleus being unstable is mathematically understood.
Please give me some examples…
There is a difference between being uncommitted and being sure that there is no creator. I suspect that most scientists are in the latter category.
That is what I was talking about. Please forgive me incorrect use of terminology. There was the inflation right after the bang that then stopped, and the current inflation. I guess that I just call both of them “inflation” and rely on context for you to figure out which one I mean.
My point was just that, back when the “big crunch” was an option, the thought of what could have caused the big bang was rather easy. Now, it isn’t.
Still, it does not necessarily mean that it is false. Imagine if humans die off. Then, in a million years, alien geologists show up and start looking for the natural process that made a cinder block. I am sure that they could come up with a theory, just probably not the right one unless they recognize that the brick in an artificial construct.
In some really nit-picky philosophical sense that is true. In that same nit-picky philosophical sense the only facts are so-called brute facts the set of which consists of nothing more nor less than your sense data. You are seeing a computer. That is a fact. The existence of that computer? That’s a theoretical inference and therefore not a fact.
It’s really tiresome to talk this way and it makes the concept of “fact” useless so I prefer not to talk about this stuff in this particular nit-picky philosophical mode. YMMV.
Do you really think you’re telling me anything new? I never said anything that contradicts this.
As I already explained, relativity and QM are not mutually exclusive. They do not contradict each other at all.
I think we’re talking entirely past each other here. I do not see “action at a distance” or “randomness” as problems in the first place. If the universe behaves the way it does because some actions seem to happen “at a distance” then so be it. My preconceptions do not have any bearing on the way the universe actually works and if the universe defies my preconceptions then so much the worse for my preconceptions. There’s no guarantee that the universe needs to make sense to bipedal apes.
As far as the many worlds interpretation, did you bother to read the link before replying? I somehow doubt it.
Since we’re talking about interpretations and not theories there are better criteria than “testable predictions” for which one is more reasonable. Namely: coherence and parsimony. Many worlds interpretation is definitely more parsimonious than Copenhagen (since it doesn’t rely on “observations” being a special kind of quantum interaction). Whether it’s more coherent depends on whether your mind has been too poisoned by sci fi movies to give the “many worlds” idea serious consideration. I dislike the name because it makes it sound fanciful but again – read the linked article. It’s not fanciful, it’s serious theoretical physics.
I’m not about to take your word on any of this since you started out saying many worlds wasn’t mathematical when it most certainly is.
But time and frequency domains are not mutually exclusive – they are consistent with each other. Copenhagen and many worlds are mutually exclusive – they contradict each other.
You said “science has proved.” I asked for a citation. Tell me how science has proved it and I’ll give you an example. Fair?
As you yourself have pointed out, this is the weakest possible argument for anything. (Apparently this isn’t a good-enough argument for multiple universes but is a good enough argument for God.)
I repeat my objection: I cannot prove I am not in the Matrix any more than I can prove there is no God. Nonetheless, I see no compelling reasons to believe I am in the Matrix. Prove to me I am not in the Matrix and I will concede there is a good reason to believe in God.
Some philosophers claim that every phenomena is caused. Note the word “philosophers” as distinct from “scientists”, although one can certainly be both.
But I have yet to see proof of this, and I believe that it’s inherently unprovable at this time.
@wysinwyg, your complaint about my hard-headed empiricism is justified. If everyone were as unwilling to believe in unproven flights of fancy as I am, scientific progress would be severely curtailed. Many great discoveries have based on ideas that seemed very implausible to people like me.
I gotta go, guys and dolls. Please do carry on!
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Lao-Tze might have something to say about that but he’s long gone.
Weren’t they laid out as Laws, not a Theory?
Newton was hellbent on proving the existence of a rational God and a clockwork Universe. And yet he gave us incredibly useful other stuff, too. Nowadays, we breed 'em more skeptical-like, and less true-believer-y. Although, you wouldn’t know it, reading the science news.
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That is a matter of terminology. They are NOT laws, however, in the sense that they are universally true. Newton works great on Earth. Near a black hole, Newton’s theories are quite inaccurate. In fact, his laws were insufficient for accurately predicting the orbit of Mercury – you needed Einstein for that one.
So to have any chance of understanding scientifically how the universe came into existence, we have to assume that the laws have an abstract, eternal character.
doesn’t the whole article boil down to statements like this? “what i think is true because otherwise I wouldn’t be able to understand truth!”
where’s the difference to just assuming a spaghetti monster or any other unverifyable theory?
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I agree. We are disagreeing on a matter of semantics…
Except when they do contradict each other…
Quantum Mechanics (QM) and relativity are both 100% accurate, so far as
we have been able to measure (and our measurements are really, really
good). The incompatibility shows up when both QM effects and
relativistic effects are large enough to be detected and then disagree.
If quantum and relatively were fully compatible and 100% accurate, we would know exactly what happens inside a black hole. We would know of wormholes were even possible. We would know if antimatter experiences anti-gravity (probably not, but an interesting enough question for scientists to try to detect using the LHC).
Do gravitons exist, or is gravity really the wapring of space, or both?
I did glance at the link, but, not being a professional scientist, the article was a little to math-intensive for the middle of the day…
I do absolutely agree that the need for an observer is the biggest problem with Copenhangen. However, as long as the results are the same and accurate predictions are made, does it really matter?
If you exclude the role of the observer, do they give different results?
OK. I get your point. There might, somewhere in the universe, at some time in the past 13 billion years, been an event that happened without a cause, despite being against all known scientific laws.
Keep in mind that a bowling ball popping into existence out of nowhere would not be against quantum theory, just amazingly, incredibly unlikely. However, it would not stay there long, and would still be governed by the Heisenberg uncertainty principle, so even that, technically, has a cause and would not count.
I am not arguing here that there WAS a creator. I am saying that there is approximately as much evidence for it as for multiple universes.
