Showing posts with label fine tuning. Show all posts
Showing posts with label fine tuning. Show all posts

Monday, January 24, 2011

Christian cosmologist says universe not fine-tuned for life: A response

Here's Rob Sheldon again, on the recent paper by Christian cosmologist Don Page on why our universe is not fine-tuned for life:
a) "fine-tuning" is in the eye of the beholder. All Page demonstrates is that his eye is different than yours. Hence the only real question is whether "fine-tuning" exists at all, not what its magnitude is. If it does exist, no matter what its size, then the universe is "special", "indeterminate", and "not necessarily so". So "fine-tuning" is a scientist's placeholder for a philosopher's contingency.

b) "Optimality" is in the mind of the beholder, depending on what the beholder knows. The "optimum" shape for a human is a sphere, if we are trying to achieve 98.6F on a planet that averages 40F. Obviously, we've left a lot out of our calculations, and equally obviously, we will never know if we left out some crucial factor. Thus we never know if our "optimum" solution is global (contains all relevant factors) or local (misses some). Drawing global (e.g., theological) conclusions from some local guess is sheer hubris, and should be laughed to derision.

c) Lambda =10^-122 Planck units means that the observations are only about 122 orders of magnitude off from what theoretical physics would estimate for this number (the Planck units.)

Let that soak in for a moment. Dembski's universal probability bound is 150 orders of magnitude, only slightly greater than this number. The 10^122 ratio of theory/observed has been called the biggest unsolved problem in physics.

It is also orders of magnitude smaller than typical error bars on other physical constants. So distinguishing it from 0.0 is more an article of faith than of science. Therefore making conclusions about revelation (what God did as observed by science) using theology (how God should work as assumed from theory) may be a fine thing for seminarians, but makes lousy science.

I'm on a hobby horse here, but putting assumptions in our method that turn out to determine our conclusions is a no-no that should invalidate a science paper. One of the many ways that peer-review has failed, is that logical nonsense doesn't get flagged any more. Science should be inductive, not deductive, and when our conclusions are contained in our assumptions, we're being deductive.

For Page to conclude that lambda =/= 0, he had to assume a model with Lambda in it to start with. Einstein inserted Lambda to get a steady state universe, and removed it when Lemaitre's expanding universe was shown to be a simpler solution. It has been reinserted to (a) explain a small anomaly with Type Ia supernovae intensities and (b) solve a "flatness" contingency problem. So if we invented it to solve the metaphysical contingency problem [and I purposely discount (a)], we cannot therefore claim that its observed existence solves the contingency problem.

d) The baryon density, which is the middle term of this deductive syllogism that goes from cosmological constant to contingency, is itself another controversial subject. The cosmological constant is all about dark energy, baryon density is all about dark matter, while "fine tuning" is all about contingent creation. Page has managed to combine the three most controversial subjects in cosmology into a logical syllogism and claim some sort of deductive power. This ought to be scientifically humorous.

The more uncertainty we add into model, the more certain our specific model must be wrong (the ratio of actual solutions/possible solutions --> 0). The fact that global warming models do not include clouds, cosmic rays, precipitation, past climate or repeatability does not mean that climate change is inevitable and deniers are being dogmatic. So also the fact that dark energy assumptions change dark matter assumptions which affect contingency assumptions should tell us our conclusions are woefully uncertain and most probably wrong.

Sunday, October 17, 2010

Multiverse: Recent studies suggest that some alternative universes "may not be so inhospitable" - assuming they exist

In "Looking for Life in the Multiverse: Universes with different physical laws might still be habitable" Scientific American Magazine (December 16, 2009) By Alejandro Jenkins and Gilad Perez make clear what is and is not accepted in science (as they understand it) and why:
The laws of physics-and in particular the constants of nature that enter into those laws, such as the strengths of the fundamental forces-might therefore seem finely tuned to make our existence possible. Short of invoking a supernatural explanation, which would be by definition outside the scope of science, a number of physicists and cosmologists began in the1970s to try solving the puzzle by hypothesizing that our universe is just one of many existing universes, each with its own laws. According to this"anthropic" reasoning, we might just occupy the rare universe where the right conditions happen to have come together to make life possible. Amazingly, the prevailing theory in modern cosmology, which emerged in the1980s, suggests that such "parallel universes" may really exist-in fact, that a multitude of universes would incessantly pop out of a primordial vacuum the way ours did in the big bang. Our universe would be but one of many pocket universes within a wider expanse called the multiverse. In the overwhelming majority of those universes, the laws of physics might not allow the formation of matter as we know it or of galaxies, stars, planets and life. But given the sheer number of possibilities, nature would have had a good chance to get the "right" set of laws at least once. Our recent studies, however, suggest that some of these other universes-assuming they exist-may not be so inhospitable after all. Remarkably, we have found examples of alternative values of the fundamental constants, and thus of alternative sets of physical laws, that might still lead to very interesting worlds and perhaps to life. The basic idea is to change one aspect of the laws of nature and then make compensatory changes to other aspects.

Our work did not address the most serious fine-tuning problem in theoretical physics: the smallness of the "cosmological constant," thanks to which our universe neither recollapsed into nothingness a fraction of a second after the big bang, nor was ripped part by an exponentially accelerating expansion. Nevertheless, the examples of alternative, potentially habitable universes raise interesting questions and motivate further research into how unique our own universe might be.
Well, the supernatural may be "outside the scope of science," but universes whose existence is not demonstrated, which are imagined principally to get out of a jam with the evidence from this universe, are reasonably doubted, despite thought experiments. The tentative tone here is well justified. It should be used more often.

See other multiverse and fine tuning stories:

Multiverse:

Cosmology: If you needn't worry about paying the rent Friday, you can worry about this stuff

Cosmology: Science's leader in things that don't make sense

Cosmology: Crisis of the month: gravitation

Cosmology: Multiverse - getting comfortable with a zillion of everything that is unique.

Cosmology: I seem to have yanked particle physicist Lawrence Krauss's chain

Cosmology: Wow. It takes guts to wage warwith Stephen Hawking. He appeared in Star Trek

Cosmology: Arguments against flatness (plus exposing sloppy science writing)

Cosmology: If the universe has free will, where do I go to file a claim for damages?

Fine tuning:

New podcasts on fine tuning of the universe

Also: Gravity doesn't make sense? Hold on to that thought!

Multiverse: Getting comfortable with a zillion of everything that is unique?

Can the laws of physics evolve?

Like clouds in our coffee, all these other universes

Major media, imagining themselves sober, think there are many universes, not just double vision

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will the cosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?

Wednesday, September 2, 2009

New podcasts on fine tuning of the universe

Two interesting ones here, from the Discovery Institute:

Cosmological Fine Tuning and the Multiverse Model

On this episode of ID the Future, Casey Luskin interviews Dr. Scott Chambers, who discusses his current research and his interest in the debate over evolution, which began in college and continues through this day.

Dr. Chambers explains how the evidence for intelligent design from the fine-tuning of the universe and the fundamental constants of physics "smacks of design," and he addresses the multiverse hypothesis.
Click here to listen.

Also, Is the earth uniquely situated for scientific observation? Do we live on a privileged planet?

On this episode of ID The Future we have a short clip about the book The Privileged Planet. In the book, authors Jay Richards and Guillermo Gonzalez suggest that earth was designed for scientific discovery. They introduce a new idea that more than just being rare in the universe, the earth is ideally located for scientific observation.

Go here to listen.

Here are some other stories on the controversy over whether the universe is fine tuned or whether there are many universes:

Gravity doesn't make sense? Hold on to that thought!

Multiverse: Getting comfortable with a zillion of everything that is unique?

Can the laws of physics evolve?

Like clouds in our coffee, all these other universes

Major media, imagining themselves sober, think there are many universes, not just double vision

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will the cosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?



(Note: If you follow me at Twitter, you will get regular notice of new Colliding Universes posts, usually when I have posted five or so stories.)

Saturday, April 18, 2009

Fine tuning

I haven't been able to post recently, due to the demands of a recent freelance job, but my friend Wintery Knight advises me that this and this are useful defenses of the fine tuning of our universe. Personally, I haven't the least doubt that our universe is fine tuned, and I am hardly interested in hearing about a zillion imaginary flopped universes as an alternative explanation.

Many years ago, a missionary doctor told me that most Africans - in the nation he was proud to serve - had little use for communists or communism because the communists said there is no God - so we can do whatever we want.

The Africans generally said, "Everyone knows there is a God. Every reasonable person can see that. The world we live in shows it clearly. What people want to know is how to get in touch with him, and get help for our problems."

I think the Africans had the better of that argument.