Sunday, September 5, 2010

Fine Tuned For Life

One of the most controversial questions in cosmology is why the fundamental constants of nature seem fine-tuned for life. One of these fundamental constants is the fine-structure constant, or alpha, which is the coupling constant for the electromagnetic force and equal to about 1/137.0359. If alpha were just 4% bigger or smaller than it is, stars wouldn't be able to make carbon and oxygen, which would have made it impossible for life as we know it to exist. Now, results from a new study show that alpha seems to have varied a tiny bit in different directions of the universe billions of years ago, being slightly smaller in the northern hemisphere and slightly larger in the southern hemisphere. 

One intriguing possible implication is that the fine-structure constant is continuously varying in space, and seems fine-tuned for life in our neighborhood of the universe. 

Human understanding of nature through science, rational reasoning, and mathematics points to a deep and still-unexplained link between life, mind, and cosmos. Somehow, the universe has engineered not only its own self-awareness, but its own self-comprehension. It is hard to see this astonishing property of (at least some) living organisms as an accidental and incidental by-product of physics, a lucky fluke of biological evolution. Rather, the fact that mind is linked into the deep workings of the cosmos in this manner suggests that there is something truly fundamental and literally cosmic in the emergence of sentience.   Paul Davies

But everything here, right down to the photons lighting the scene after an eight-minute jaunt from the sun,  bears witness to an extraordinary fact about the universe: Its basic properties are uncannily suited for life. Tweak the laws of physics in just about any way and—in this universe, anyway—life as we know it would not exist.

Consider just two possible changes. 

Atoms consist of protons, neutrons, and electrons. If those protons were just 0.2 percent more massive than they actually are, they would be unstable and would decay into simpler particles. Atoms wouldn’t exist; neither would we. 

If gravity were slightly more powerful, the consequences would be nearly as grave. A beefed-up gravitational force would compress stars more tightly, making them smaller, hotter, and denser. Rather than surviving for billions of years, stars would burn through their fuel in a few million years, sputtering out long before life had a chance to evolve.

There are many such examples of the universe’ life-friendly properties so many, in fact, that physicists can’t dismiss them all as mere accidents.  We have a lot of really, really strange coincidences, and all of these coincidences are such that they make life possible,  Linde says.  Strikingly, the temperature of space is everywhere the same, just 2.7 degrees Celsius above absolute zero. How could different regions of the universe, separated by such enormous distances, all have the same temperature?  In the standard version of the Big Bang, they couldn’t. The universe as a whole has been cooling ever since it emerged from the fireball of the Big Bang. 

But there’s a problem: For all of it to reach the same temperature, different regions of the universe would have to exchange heat, just as ice cubes and hot tea have to meet to reach the uniform temperature of iced tea. But as Einstein proved, nothing, including heat, can travel faster than the speed of light. In the conventional theory of the Big Bang, there simply hasn’t been enough time since the universe was born for every part of the cosmos to have connected with every other part and cooled to the same temperature.

Sciences Alternative to an Intelligent Creator: the Multiverse Theory :  Discover Magazine
to-an-intelligent-creator () " 
by Tim Folger ;  published online November 10, 200

The Shape of the Universe as Mapped by NASA

NASA's Cosmic Background Explorer (COBE) satellite rocketed into Earth orbit on Nov. 18, 1989, and quickly revolutionized our understanding of the early cosmos. Developed and built at Goddard Space Flight Center in Greenbelt, Md., COBE precisely measured and mapped the oldest light in the universe -- the cosmic microwave background. 

For these results, COBE scientists John Mather, at Goddard, and George Smoot, at the University of California, Berkeley, shared the 2006 Nobel Prize in physics. The mission ushered cosmologists into a new era of precision measurements, paving the way for deeper exploration of the microwave background by NASA's ongoing WMAP mission and the European Space Agency's new Planck satellite.

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