The New Scientist article notes:
QUOTE
One of [the researchers'] main motivations is the need to explain why the physical laws underlying our universe seem so finely tuned as to allow galaxies, stars, planets, complex chemistry, life - and us - to exist. Rather than appealing to God or blind luck.....
The Scientific American article makes a similar point:
QUOTE (->
| QUOTE |
| One of [the researchers'] main motivations is the need to explain why the physical laws underlying our universe seem so finely tuned as to allow galaxies, stars, planets, complex chemistry, life - and us - to exist. Rather than appealing to God or blind luck..... |
The Scientific American article makes a similar point:Fundamental constants are finely tuned for life. A remarkable fact about our universe is that physical constants values needed to allow for complex structures, including living things. Steven Weinberg, Martin Rees, Leonard contend that an exotic multiverse provides a tidy explanation for this apparent coincidence: if all possible enough collection of universes, then viable ones for life will surely be found somewhere.
I also recall a similar point being made by an astrophysicist in a radio interview on multiverses, in which he said that if we were to rule out multiverses, 'anthropic reasoning' would strongly support a theistic view of the origin of the universe.
Aside from this, both articles also note that there are a plethora of competing 'multiverse views', including those which posit an infinite number of worlds exactly the same as this, and an infinite number of variations which only differ by one particular.
So, from the viewpoint of an educated layman, I have a few questions.
First, is it possible that a lot of this speculation is, in fact, being driven by scientific antipathy to religious ideas of Creation? In other words, if, in the absence of the multiverse, the Universe looks very much like the intentional creation of a higher intelligence, is this in itself one of the underlying motivations for entertaining these ideas?
And if this is so, is that a good reason for entertaining them?
Second, if multiverse speculations were suddenly deemed not to be feasible, what major current cosmological theories would have to be abandoned? I mean, it seems that multiverse gives you a lot of elbow-room to engage in almost any type of hypothesizing, because no matter how outlandish your idea, it could exist in 'a possible universe'.
All big questions, I know. But I can't help but be reminded of the medieval debates over how many angels could dance on the head of a pin. Strong sense of deja vue!
Multiverses do not rank as theories, nor even testable hypotheses, which is the primary reason there is such a variety of them. There's just no feasible way to narrow the field of candidates. As yet, this is speculation which most likely has been artificially elevated to the height of hypothesis or theory by the wishful thinking of those very likely antipathetic to religion.
I view this as a symptom of atheistic apologetics. Atheists tend to elevate scientific speculation, even if highly speculative, as having some sort of future promise accorded to it base solely on the past success of science in general. Especially where the speculation may usurp some religious belief.
The reasoning about a multiverse may be sound enough, but without solid evidence it's just as much wishful thinking as religion could be characterized as.
I view this as a symptom of atheistic apologetics. Atheists tend to elevate scientific speculation, even if highly speculative, as having some sort of future promise accorded to it base solely on the past success of science in general. Especially where the speculation may usurp some religious belief.
The reasoning about a multiverse may be sound enough, but without solid evidence it's just as much wishful thinking as religion could be characterized as.
There're strong efforts to create testable multiverse theories. Everyone knows that the current ideas aren't true theories, but they think that the effort is worthwhile. SOME of the theories create hypotheses, and some of the other ideas might generate other hypotheses.
So, the criticism is valid. The good news is that it's accepted as valid.
The biggest 'worry' is that our multiverse really IS the type of multiverse that cannot be tested. There's no guarantee that it isn't. We might live in a multiverse that can be cracked with hypotheses and experiments, but we might not. That still makes the generation of hypotheses useful, because ruling out "what is" has its own value. We won't know if it's unknowable, but we can slowly rule out where it's knowable
I quite enjoyed Lee Smolin's book on 'loop quantum gravity' as a synopsis of the problem and a synopsis of some of the solutions. As well, Brian Greene currently hosts a PBS series on the cosmos, and one of the episodes is on multiverse theories.
http://www.youtube.com/watch?v=-FGgkfsMpCs
So, the criticism is valid. The good news is that it's accepted as valid.
The biggest 'worry' is that our multiverse really IS the type of multiverse that cannot be tested. There's no guarantee that it isn't. We might live in a multiverse that can be cracked with hypotheses and experiments, but we might not. That still makes the generation of hypotheses useful, because ruling out "what is" has its own value. We won't know if it's unknowable, but we can slowly rule out where it's knowable
I quite enjoyed Lee Smolin's book on 'loop quantum gravity' as a synopsis of the problem and a synopsis of some of the solutions. As well, Brian Greene currently hosts a PBS series on the cosmos, and one of the episodes is on multiverse theories.
http://www.youtube.com/watch?v=-FGgkfsMpCs
El Machinae,
Most of that is true. I'd only point out that, for many scientists, nothing is ruled out until an alternative is proven. This means that many scientists will never definitively give up the idea. If we cannot test a particular multiverse scenario, then all null tests are accepted, on faith, as evidence of this scenario, simply because they find scenarios which leave the way open for non-scientific explanations unpalatable.
Strictly speaking, the scientific method only accepts things for which evidence can be found. All else is speculation and wishful thinking.
Or just equally apply the atheistic sentiment, "absence of evidence is evidence of absence".
I have the Smolin and Greene books. Both good, but perhaps without a clear demarcation of where evidence ends and speculation begins, as is common in popular science books.
Most of that is true. I'd only point out that, for many scientists, nothing is ruled out until an alternative is proven. This means that many scientists will never definitively give up the idea. If we cannot test a particular multiverse scenario, then all null tests are accepted, on faith, as evidence of this scenario, simply because they find scenarios which leave the way open for non-scientific explanations unpalatable.
Strictly speaking, the scientific method only accepts things for which evidence can be found. All else is speculation and wishful thinking.
Or just equally apply the atheistic sentiment, "absence of evidence is evidence of absence".
I have the Smolin and Greene books. Both good, but perhaps without a clear demarcation of where evidence ends and speculation begins, as is common in popular science books.
QUOTE (El_Machinae+Dec 23 2011, 05:25 PM)
There're strong efforts to create testable multiverse theories. Everyone knows that the current ideas aren't true theories, but they think that the effort is worthwhile. SOME of the theories create hypotheses, and some of the other ideas might generate other hypotheses.
So, the criticism is valid. The good news is that it's accepted as valid.
The biggest 'worry' is that our multiverse really IS the type of multiverse that cannot be tested. There's no guarantee that it isn't. We might live in a multiverse that can be cracked with hypotheses and experiments, but we might not. That still makes the generation of hypotheses useful, because ruling out "what is" has its own value. We won't know if it's unknowable, but we can slowly rule out where it's knowable
I quite enjoyed Lee Smolin's book on 'loop quantum gravity' as a synopsis of the problem and a synopsis of some of the solutions. As well, Brian Greene currently hosts a PBS series on the cosmos, and one of the episodes is on multiverse theories.
http://www.youtube.com/watch?v=-FGgkfsMpCs
So, the criticism is valid. The good news is that it's accepted as valid.
The biggest 'worry' is that our multiverse really IS the type of multiverse that cannot be tested. There's no guarantee that it isn't. We might live in a multiverse that can be cracked with hypotheses and experiments, but we might not. That still makes the generation of hypotheses useful, because ruling out "what is" has its own value. We won't know if it's unknowable, but we can slowly rule out where it's knowable
I quite enjoyed Lee Smolin's book on 'loop quantum gravity' as a synopsis of the problem and a synopsis of some of the solutions. As well, Brian Greene currently hosts a PBS series on the cosmos, and one of the episodes is on multiverse theories.
http://www.youtube.com/watch?v=-FGgkfsMpCs
http://arxiv.org/abs/1012.1995
QUOTE (^+)
Thus, while we might rule out these features as being due to systematics or foregrounds, better data would be needed to definitively establish the bubble collision hypothesis.
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