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A Skeptical Look At The Multiverse
sjanich writes "The NY Times has a short, interesting article on multiverse theory. The author, Paul Davies, writes: 'This idea of multiple universes, or multiple realities, has been around in philosophical circles for centuries. The scientific justification for it, however, is new.' It is quite an interesting read. The author is a Physicist and pretty good science writer." Davies is not kind to the multiverse theory.
http://www.hedweb.com/everett/everett.htm
Taking the multiverse theory at face value, therefore, means accepting that virtual worlds are more numerous than "real" ones. There is no reason to expect our world -- the one in which you are reading this right now -- to be real as opposed to a simulation.
I mean, what's the problem with this? Until we find evidence to the contrary, it remains a distinct possibility. And it borders on the realm of so-what. Is the knowledge that you're actually a participant in a very large simulation going to change how you live your life?
I mean, are you annoyed that when you fall, you accelerate at exactly 9.8 m/s^2 (in a vacuum) towards the center of the earth, without fail? Those unimaginative programmers...
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
Why is nature so ingeniously, one might even say suspiciously, friendly to life?
Well, this is one to ponder, granted that you consider life to be basically an earthbound form or entity. It always amuses me that there is talk about whether this place or that could support life. Just because we, as earthbound beings, rely on certain conditions to live, who is to say that other lifeforms would live in something that we'd consider completely destructive to our own very nature. How do we know that there aren't life forms out there that don't depend on breathing molten gold in the same way we need to breathe oxygen? Or to take it even farther, who says they need to breath at all?
But to come back on topic, I think that the multiverse theory is a very interesting one. I think it's possible. Why? Because it's interesting that way. =0)
*slight crashing sound*
Everywhere he says life could not exist in any other universal properties and constants should be modified to state "life as we know it."
quote:
Life would probably be impossible with more (or less) than three dimensions to work with, so our seeing three is then no surprise. Similar arguments apply to other supposedly fixed properties of the cosmos, such as the strengths of the fundamental forces or the masses of the various subatomic particles.
Why exactly is life impossible with more than 3 dimensions? He subscribes to the fundenmental flaw that all science fiction writers subscribe to: all alien life forms breath, walk on legs, and "see" through eyes. Sure, it's hard to change a human actor on a movie screen by too much, but the world of books and pages ought to be able to create something better.
I also agree with the other post that says, paraphrased, if we live in a giant simulation, does that make existance different? If you can't get out of, or control the simulation, what difference does it make? I, for one, am not worried about hyperintelligence alien giants looking at me showered naked, and the like.
Along those same lines, if we can eventually create computer simulations with sentiant beings, why can we not create a universe with different parameters and force life to exist within it?
Lastly, if we can't get out of this universe into another one, what difference does it make? And if we somehow break the barrier and jump universes, the link between them makes them one universe with localized properties doesn't it?
-Ryan
AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
This article annoyed me, because it felt like the author reasoned backwards from his own prejudice. It seemes as if he has an actual abhorence of the very idea of multiple universes, perhaps because that would make our own little universe less than special.
He claims multiverse theories are all by nature unverifiable. Hogwash. Off the top of my head, I can think of at least one type of multiverse theory that would be. Scientists now speculate that we may live on a higher-dimensional 'sheet' or brane, as they call it, with others along side ours. Gravity from the nearby branes affects ours and vice versa. This effect could possibly be calculated and tested. Just because the theories can't currently be verified doesn't mean that they are without merit.
He seems to have a special problem with there being more virtual universes than real ones, but it makes no sense. Even if there was only one universe, there would likely be more than one virtual universes within it. We still would have no way of knowing if we were in the original, 'real' universe, or a virtual knock-off.
He also claims that multiverse theories require gods or creators at all levels and scales. This is where his religious bias becomes utterly apparant. He is uncomfortable with the idea of there not being one true creator from which everything else springs. He claims the idea of infinite regress of creator/created dyads is a type of logical fallacy known as reductio ad absurdum, which means reduction to the ansurd, but it is not.
Reductio ad absurdum is disproof of a proposition by showing that it leads to absurd or untenable conclusions. His "untenable conclusions" are a radically revised relationship between the Devine and Its human creations. News flash: just because you find something absurd doesn't mean it isn't true. And just because a scientific theory requires you to revise your idea of some personal creator-god doesn't mean that theory is absurd. Reductio ad absurdum is more properly used when you show that, for instance, your opponants argument prooves that up is down, or some other obvious nonsense.
If any theory is unverifiable, it is the theory of a personal creator-god. If it was verifiable, we wouldn't need faith.
This is anti-scientific religious hogwash, not a reasoned scientific article. What really pisses me off is that the author, Paul Davies, is a professor of natural philosophy, and should know better than to misuse terms like reductio ad absurdum.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
The existence of intelligent life does require the universe to be large and complex. The multiverse interpretation demonstrates a related point: the probability of intelligent life arising in this universe might be low, or even very low. You don't need the multiverse interpretation to work this out, but it does make it a lot clearer. The ET searchers often express the assumption that our existence shows that intelligent life is likely to have a probability greater than one (because here we are). The fallacy that the size/complexity of the universe (which came first) caused intelligent life (which came later) is an easy mistake. You really need the multiverse interpretation to see that it is a selection effect fallacy. Note that the multiverse interpretation doesn't have to be "true" to fill this role, just one consistent way of looking at the issue.
This isn't a case of anthropomorphism or earth-centrism or anything like that. It's an outcome of basic physics (it does take into account that physics may be different in other universes, though).
To take a simple example at the grossest level: imagine a universe in which symmetry broke in such a way that instead of three macroscopic spatial dimensions resulting, there were only two. A two-dimensional universe would be incapable of hosting structures of very significant complexity such as multicellular lifeforms. There would be strict limitations on size becaues a 2-D lifeform cannot possess any kind of internal transport system for alimentation or circulation - it would simply fall apart (try drawing one and see how internal channels effectively divide the creature into pieces).
Four dimensional universes (and higher order dimensional spaces) also have topological problems which would make life difficult though you'll have to look those up for yourself.
Even in three dimensional universes, very slight modifications to the relative strength of the four fundamental post-symmetry-breaking forces would make the universe appear very different.
There will be universes composed entirely of radiation - but radiation does not interact well enough to form structures spontaneously.
There will be universes where stars shine but never explode, thus elements heavier than helium are never released from their cores - and you can't get interesting chemical reactions from just hydrogen and helium.
There will be many dark universes where star-sized agglomerations of matter simply do not ignite at all, thus energy cannot be concentrated sufficiently enough in any one place to fuel a biosphere.
Even if you had hot stars and an interesting array of elements it may still be devoid of life if there was no possible *simple* (and thus common) combination of those elements available to provide a molecule like water - slightly more than weakly polar, which remains liquid at a range of useful temperatures (warm enough to enable chemical reaction at a significant rate, cool enough to allow stable reaction products).
It's all very well to postulate "energy beings" or Horta-style silicon-based lifeforms but basic physics just doesn't make these very likely. There are strong practical reasons why all life on Earth is based on water and carbon compounds. There may be other constellations of physical laws which could generate a universe complex enough to support life, but there are far, far more that couldn't, no matter how good your imagination is.
> > Why is nature so ingeniously, one might even say suspiciously, friendly to life?
> Well, this is one to ponder, granted that you consider life to be basically an earthbound form or entity. It always amuses me that there is talk about whether this place or that could support life. Just because we, as earthbound beings, rely on certain conditions to live, who is to say that other lifeforms would live in something that we'd consider completely destructive to our own very nature. How do we know that there aren't life forms out there that don't depend on breathing molten gold in the same way we need to breathe oxygen? Or to take it even farther, who says they need to breath at all?
Also, when people start arguing that the universe is uniquely suited for life it is useful to ask them what percentage of the universe is actually hospitable to life AWKI.
A thin crust at the surface of a few planets, out of the entire volume of the universe? It looks to me like the universe was "designed" for something else altogether, and life found a few rare, small cracks to hide in. As well to say that the lobby of a fine hotel was designed to harbor dust particles.
Sheesh, evil *and* a jerk. -- Jade
Paul Davies is a religious person. And so when there are two competing theories, one of which includes his ideals of religion, and one which does not, he will choose the first if there is no other evidence given. The reason that the multiverse theory is postulated is to give a kind of evolutionary account of the cosmology of the universe. Who knows if there are other universes, or if they are anything like our own? We certainly will never know.
But Davies' favored alternative is a much less viable option. To explain away the existence of our world with something that's even more complicated, such as God, is no explanation at all. Explanations reduce complex things to simple things. And if God can create something as complex as the universe, he must clearly have at least that much complexity within Himself.
We've seen this conflict before. Look at these well designed humans! How could they have possibly arrived upon this Earth? Surely only a being as complex as God could have accomplished such a wonderful feat! This was the great argument of the last two centuries, and the consensus is that evolution and natural selection form a much better explanation than divine creation.
And I guess not much has changed since then. Look at this well designed universe! If things were only slightly different, no life could have been formed at all. Surely there is a divine influence at work! But whenever you drop something like God into your explanation, you've only made your job harder. Now instead of explaining life or the universe, you have to explain the existence of this vastly powerful and mysterious creature that made it all take place.
The other possibilities, though possessing many flaws, are much more plausible. It's much more plausible to think that many universes were created, and that only those suitable for life actually developed life, than it is to think that there is only one universe, whose existence can only be explained though divine creation.
I understand it lets you get away with not having to treat the observer of the quantum event as seperate and somehow special.
This seems less arbitrary to me... Copenhagen's interpretation makes a big assumption about the role of the observer.
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
Actually the article is about a seperate of multiverse theory, though they are compatible. You described quantum multiverse where every event that can happen does happen. The article discusses big-bang multiverse where there are many (or infinite) big-bangs. Each big-bang would create a seperate universe with it's own random variation on the laws of physics.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
> The May issue of Scientific American contains a much more in-depth article on parallel universes
Just finished it. (Love that day every month when I drop everything and browse the new issue!)
> The first type of "parallel universe" is just another part of this universe. Because the universe appears to be infinitely large, any configuration of matter - be it Earth, our galaxy, or our entire currently-observable universe - must be duplicated somewhere out there.
I didn't get his calculations. He gives the number of protons that could fit into our observable universe ("Hubble space") and then calculates the permutations of present/absent for each to get the total number of possible configurations. But wouldn't there be more configurations than a present/absent calculation would account for? Such as variants arising from the momentum and quantum state of each proton?
Also, ISTM that many of those states would be impossible, in the sense that the couldn't arise in any part of the universe where the same laws of nature apply. E.g., you won't find neutron stars that are cylinders rather than spheres.
> The fourth type of parallel universe discussed is, as far as I can tell, imaginary universes. The idea is to consider an arbitrary mathematical description of an object a spacetime diagram, and to consider the result of interpretation of this diagram to be a universe.
Yeah, the author admits his prejudice that mathematics is universal (or shall we say "multiversal"), and his level IV is the collection of all mathematically possible universes. Anyone who doesn't share his prejudice (such as me) might posit a level V, which is a collection of level IV universes - one for each possible "variant" mathematics.
Sheesh, evil *and* a jerk. -- Jade