What is the firing squad argument for 'fine-tuning' in the universe?

Astronomer Deborah Haarsma explains philosopher John Leslie's analogy of a firing squad as a defence for the anthropic principle, or fine-tuning in the universe.

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Education

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• Deborah Haarsma
• anthropic principle
• philosophy
• science
• faith
• religion
• Christianity
• astronomy

[grunderlyme]

Gnom--Your analogy is wrong. Here' why: (1) We KNOW how many constants there are, 30-50 constants and various laws, initial conditions, & other physical quantities. (2) We KNOW what happens when you alter one only slightly within a very small range: hydrogen stars wouldn't form, the universe would have re-collapsed. (3) We KNOW each constant is, not only independently fine-tuned for life within a very small target range, but also to each other. You bet this is evidence of a BIAS toward life.

[grunderlyme]

"Problem with Penrose's argument is you can make the universe arbitrary "improbable" by making up some combinatorial argument"

--Yeah, even though the same fine-tuning evidence pops up at every corner when comparing the Initial conditions, Laws, constants, & other physical quantities from independently specified classes. These numerous probabilistically LOW ratios come from leading physicists Penrose, Ellis, Reese, Collins, Davies, Tipler, Hawking, Hoyle, etc. They must be dumb, I guess

[grunderlyme]

"assumes laws can be other than what they are"

-This isn't an "assumption." There is nothing necessary about the Laws, constants, or initial conditions, since we've already looked and found no physical mechanism that would make them that way. Failing to produce this mechanism time & again is a solid reason to reject it, just as scientists rejected Aether for the same reason. Why are so many looking to a Multiverse now?--Because they've abandoned your idea. The universe is radically contingent

[grunderlyme]

"his number is meaningless"

--False. We arrive at these numbers by plugging in a range of possible values for each constant while holding fixed the known Laws of the universe. We then find that the range of non-life-permitting values greatly exceeds those which are life-permitting, and this follows as a matter of mathematical necessity given the KNOWN Laws of OUR universe. So either our Laws are false and Penrose is stupid, or you haven't the 1st clue what you're talking about

[grunderlyme]

"you need a probability for God and compare it w the low number of nature existing"

--False. I don't need to know the prior probabilities of hypotheses G and ~G to know that the evidence L confirms one over another. I only need to know the respective likelihoods of life given each: L|G and L|~G. For instance, it is much LESS surprising (or more epistemically likely) the constants are fine-tuned for life if we knew God fine-tuned them, than being a result of chance. So L confirms G over ~G

[Gnomefro]

@CartesianTheist If you want to infer supernatural things you have to produce a probability estimate for God and compare it with the low number you produced for nature existing, otherwise you're not actually making a valid probabilistic argument. Either way, the final death of the supernatural hypothesis comes with the fact that it insists on positing the infinitely complex as an an "explanation" for complexity. That just amounts to stating that complexity doesn't need explanation so why bother

[Gnomefro]

@CartesianTheist What this means is that nobody has any reason to think "argument from tiny made up numbers" is indication of anything supernatural. It could mean that there is an underlying phenomena dictating whatever is observed, but we have no more reason to think it's not natural than we would if we made a probability argument dealing with how balls fall uncannily similar all over the earth.

[Gnomefro]

@CartesianTheist In short, it should be obvious to anyone that Penrose is presenting a triviality equivalent to stating that "If the universe was different, then it would be different." Even if the universe was entirely random in some way, the only thing that would make it improbable is if whatever number you produced, for example 1x10x10^123, is small compared to the number of trials. Penrose has no idea how many trials there are, and consequently his number is meaningless.

[Gnomefro]

@CartesianTheist "It's not an argument based on the probability of our universe as a whole. It's an argument based on the laws being what the laws are and the astounding delicate balance of them being what they are."

This statement assumes that the laws of nature can be other than what they are. Penrose does not know this. Also, simple equilibrium effects would produce laws that are "astoundingly delicate" by necessity. What are the chances that a scale will balance with equal weights?

[Gnomefro]

@CartesianTheist That there are philosophers that disagree with me is essentially a non-statement. You can dig up philosophers supporting any self refuting view what so ever. The problem with Penrose's argument is that you can make the universe arbitrary "improbable" by making up some kind of combinatorial argument about, for example, the state of every atom or, like Penrose, limit yourself to, the state of natural laws.