jueves, 27 de junio de 2013

Fine Tuning

Implications of Supernatural Intelligence in the Fine-tuning of Universal Constants
There are several conditions of our universe necessary for the emergence of any complex life form. Many of these conditions are so exceedingly improbable that it is not reasonable to expect that they could have occurred by pure chance For this reason many physicists attribute their occurrence to supernatural design. Some other physicists prefer to believe instead in trillions upon trillions of “other universes” (which are unobserved and likely unobservable). Before discussing which explanation is more probative, we need to explore some specific instances of this highly improbable fine-tuning. We may break the discussion into two parts:
1. The exceedingly high improbability of our low entropy universe, and
2. The exceedingly high improbability of the anthropic values of our universe’s constants.
We will discuss each in turn.
The high improbability of a pure chance occurrence of our low-entropy universe
A low-entropy universe is necessary for the emergence, development, and complexification of life forms (because a high entropy universe would be too run down to allow for such development). Roger Penrose has calculated the exceedingly small probability of a pure chance occurrence of our low–entropy universe as 10^10^123 to one. How can we understand this number? It is like a ten raised to an exponent of:
100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.
This number is so large, that if every zero were 10 point type, our solar system would not be able to hold it! Currently, there is no natural explanation for the occurrence of this number, and if none is found, then we are left with the words of Roger Penrose himself:
“In order to produce a universe resembling the one in which we live, the Creator would have to aim for an absurdly tiny volume of the phase space of possible universes—about 1/10^10^123 of the entire volume, for the situation under consideration.”
What Penrose is saying here is that this occurrence cannot be explained by a random (pure chance) occurrence. Therefore, one will have to make recourse either to a multiverse (composed of bubble universes, each having different values of constants) or as Penrose implies, a Creator (with a super-intellect).
The high improbability of five other anthropic conditions (based on cosmological constants)
A cosmological constant is a number which controls the equations of physics, and the equations of physics, in turn, describe the laws of nature. Therefore, these numbers control the laws of nature (and whether these laws of nature will be hospitable or hostile to any life form). Some examples of constants are: the speed of light constant (c= 300,000 km per second), Planck’s constant ( = 6.6 x 10-34 joule seconds), the gravitational attraction constant (G = 6.67 x 10-11 ), the strong nuclear force constant (gs = 15), the weak force constant (gw = 1.43 x 10-62), the mass of the proton (mp = 1.67 x 10-27 kg), rest mass of an electron (me = 9.11 x 10-31 kg), and charge of an electron proton (e = 1.6 x 10-19 coulombs). There are several other constants, but these pertain to the following anthropic coincidences (highly improbable conditions required for life).
(i) If the gravitational constant (G) or weak force constant (gw) varied from their values by an exceedingly small fraction (higher or lower) -- one part in 10^50 (.00000000000000000000000000000000000000000000000001) then either the universe would have suffered a catastrophic collapse or would have exploded throughout its expansion, both of which options would have prevented the emergence and development of any life form. This cannot be reasonably explained by pure chance.
(ii) If the strong nuclear force constant were higher than its value (15) by only 2%, there would be no hydrogen in the universe (and therefore no nuclear fuel or water -- this would have prohibited life). If, on the other hand, the strong nuclear force constant had been 2% lower than its value then no element heavier than hydrogen could have emerged in the universe (helium, carbon, etc). This would have been equally detrimental to the development of life. This “anthropic coincidence” also seems to lie beyond the boundaries of pure chance.
(iii) If the gravitational constant, electromagnetism, or the “proton mass relative to the electron mass” varied from their values by only a tiny fraction (higher or lower), then all stars would be either blue giants or red dwarfs. These kinds of stars would not emit the proper kind of heat and light for a long enough period to allow for the emergence, development, and complexification of life forms. Again, these “anthropic coincidences” are beyond pure chance occurrence.
(iv) If the weak force constant had been slightly smaller or larger than its value, then supernovae explosions would never have occurred. If these explosions had not occurred, there would be no carbon, iron, or earth-like planets.
(v) Fred Hoyle and William Fowler discovered the exceedingly high improbability of oxygen, carbon, helium and beryllium having the precise values to allow for both carbon abundance and carbon bonding (necessary for life). This “anthropic coincidence” was so striking that it caused Hoyle to abandon his previous atheism and declare:
“A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”
(For all five “anthropic coincidences,” refer to NPEG Chapter One, Sect. II and Lectures #5 and 6 of PID.)
The odds against all five of the anthropic coincidences happening randomly is so exceedingly improbable that it is like telling a monkey to type out the corpus of Shakespeare perfectly by random tapping of the keys. After returning two weeks later the entire corpus of Shakespeare, Hamlet, Macbeth, Richard III, are all perfectly recounted. Most reasonable and responsible individuals would not attribute this to random occurrence (because the odds are so overwhelmingly against it), and so, they look for another explanation which is more reasonable and responsible.
For this reason, no respectable physicist (including Stephen Hawking), believes that these anthropic coincidences can be explained by pure chance. In view of the fact that no natural explanation has been found for them, most physicists have made recourse to two trans-universal explanations:
1. A multiverse (a naturalistic explanation) and
2. A super intellectual Creator (a supernatural explanation).
Is the naturalistic explanation more reasonable and responsible? Not necessarily because the other universes (and the multiverse itself) are in principle unobservable. Furthermore, it violates the principle of parsimony (Ockham’s Razor) – the explanation with the least number of assumptions, conditions, and requirements is to be preferred. As Paul Davies notes:
Another weakness of the anthropic argument is that it seems the very antithesis of Ockham’s razor, according to which the most plausible of a possible set of explanations is that which contains the simplest ideas and least number of assumptions. To invoke an infinity of other universes just to explain one is surely carrying excess baggage to cosmic extremes … It is hard to see how such a purely theoretical construct can ever be used as an explanation, in the scientific sense, of a feature of nature. Of course, one might find it easier to believe in an infinite array of universes than in an infinite Deity, but such a belief must rest on faith rather than observation.[8]
3. All known multiverse theories have significant fine-tuning requirements. Linde’s chaotic inflationary multiverse cannot randomly cough out bubble universes because they would collide and make both universes inhospitable to life; the bubble universes must be spaced out in a slow roll which requires considerable fine-tuning in the multiverses initial parameters.[9] Similarly, Susskind’s String Theory landscape requires considerable meta-level fine-tuning to explain its “anthropic" tendencies.[10]
Conclusions

Given these problems, is the multiverse a more reasonable and responsible explanation of our universe’s anthropic coincidences? Many physicists believe that it is not, not only because of the above three problems, but also because of the likelihood of a Creator. When the evidence for a beginning (a Creator) is combined with the exceedingly high improbability of the above anthropic coincidences, a super intellect may be the most reasonable and responsible explanation because it avoids all the problems of a hypothetical multiverse. Thus, it is both reasonable and responsible to believe on the basis of physics, that there is a very powerful and intlligent being that caused our universe to exist as a whole.

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