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Post by unkleE on Jan 7, 2009 8:35:50 GMT
Jim,
I wanted to thank you and compliment you on this post on the blog. It was very clear and opened up a few ideas I had never really thought through - e.g. the clarification about Occam's razor (though I still think it should be Ockham!) and the idea that alternatives to "life as we know it" might in fact be metaphysical rather than scientific.
The teleological argument and the cosmological argument were not very powerful when I was a lad (too many years ago now!), but it seems that, as the new atheists heat up the arguments, the big bang and the fine-tuning of the universe have raised the value of these arguments greatly. Another coincidence?
Thanks again.
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Post by Al Moritz on Jan 7, 2009 20:26:09 GMT
Yes, thanks Jim for clarifying Occam's razor so well; I agree with Unklee that this is an important point.
The only reasonable objection with respect to numeric simplicity might be that a multiverse proponent might say that it is really all just one universe: it started by eternal inflation and all the single universes forming the multiverse are just bubbles" from that gigantic mother universe. This objection could hold only for the eternal inflation scenario, not for the multiverse of "anything possible does in fact exist", of causally disconnected universes.
***
As for alternatives to "life as we know it": I would still call the exotic particles where it would be formed from "matter". However, most likely any life would still be exceedingly rare.
Here are some thoughts that I had written a while ago:
But wait a minute, the atheist will say: perhaps “life as we know it” may be extremely unlikely, but couldn’t it be that many different forms of life were possible and thus that life in any form is not unlikely at all?
One who studies this issue sufficiently will know that not just life as we know it, but any chemical complexity requires highly specialized laws of nature.
Any detuning, and any chemical complexity would be impossible. Just hydrogen, and possibly deuterium and helium (or equivalents), and no chemistry.
We know that material life requires complexity of matter, and complexity of matter is impossible without chemistry. Therefore, if several of the physical constants were freely variable, then the chances to arrive at any laws of nature that allow for material complexity – thus any kind of life, not just life as we know it – would be very low. Our universe with its specific laws of nature would be a small oasis within a vast desert of a humongous number of sterile, non-complex universes where no chemistry takes place.
If, on the other hand, there would be a completely different kind of life in a completely different kind of universe with laws of nature that do not at all resemble what we have (and which also produce entirely different particles), it is still the most rational assumption that this life would be based as well on some material complexity, which in turn would be based on some sort of alien chemistry (being a semi-closed system and metabolism require complexity, there is no disputing that). And furthermore, we would rationally expect by extrapolation from our laws of nature (we have nothing else to go by) that also here any slight detuning of physical constants would make that alien chemistry impossible.
Thus, another small oasis within a vast desert of a humongous number of sterile, non-complex universes where no chemistry takes place.
Overall, then, even if some entirely different form of life might be possible somewhere else under completely different conditions, the probability for any life, known or unknown, most likely still remains very low.
The argument might be brought up, “life could theoretically occur in ways we would never imagine, or would not even think of as life at all”. Yet the idea of life without any chemical complexity (e.g. in stars), leads one into regions of thought that are not seriously debatable anymore and which have no basis in our knowledge from science. Also, I have never seen it discussed in those terms by a scientist. Imaginative thinking is one thing, wild baseless science-fiction another.
Al
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Post by jim_s on Jan 11, 2009 21:50:39 GMT
Thanks guys, I really appreciate it. Al, I thought about substituting "chemical complexity" for "life" but decided that it would have taken another 3000 words to explain. But I think it would be a profitable way to expound the Anthropic Principle to those who think there isn't anything special about life.
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