ericmurphy
Posts: 2460
Joined: Oct. 2005
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I'm getting into this debate a little late; sorry I'm responding to a post from three weeks ago.
| Quote (The Ghost of Paley @ Oct. 21 2006,03:54) | | This is why they conditioned on L. Too bad they also didn't condition on Fine-Tuning, even though it's observed and is valid "background information". |
But I'm not sure "fine tuning" has been observed.
The prime candidate for a "finely tuned" constant is, of course, the Cosmological Constant. It's got to be what it is within 120 orders of magnitude (and, probably not coincidentally, is mispredicted by most current theories by about 120 orders of magnitude), or the universe would either have immediately recollapsed, or immediately have expanded to infinity.
As far as anyone knows, there are no constraints on what the cosmological constant could be. One of the principal objects to string theory as it's currently constituted is its inability to pick out one set of physical parameters out of 10^500 mathematically-consistent possibilities. But given our limited understanding of why any physical parameter takes the value it does in the observable universe, I think it's premature to take it as a given that fine tuning has been observed. For all we know (and this is certainly the fondest hope of the high-energy physics community), there may in fact be only one mathematically-consistent value for all or most physical parameters, which of course would render the fine-tuning matter moot (a point I-J make in their paper.)
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2006 MVD award for most dogged defense of scientific sanity
"Atheism is a religion the same way NOT collecting stamps is a hobby." —Scott Adams
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