Intelligent Design, the best explanation of Origins

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Intelligent Design, the best explanation of Origins » Astronomy & Cosmology and God » The force of Gravity - evidence of fine tuning

The force of Gravity - evidence of fine tuning

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The Force of Gravity

It is now known that if the force of gravity were any weaker, stars would not have compacted tight enough together so that nuclear fusion would occur. Fusion is necessary to produce the heavier elements upon which life depends (such as carbon, nitrogen and oxygen) ---and without fusion, there would only be hydrogen and helium in all the universe. On the other hand, if gravity were any stronger, stars would burn so hot that they would burn up in about one year or so (ref. G. Easterbrook, cited, p.26). As it is, the gravitational force is so finely tuned, that the average star is capable of burning in a stable fashion for about 80 billion years (ref. H. Ross, cited, p.60).

How finely tuned is gravity? -- Well, the strength of gravity could be at any one of 14 billion billion billion settings, but there is only one setting which is adequate (and optimal) for a universe with intelligent life to exist.

-- To illustrate: This is as if you had a measuring tape with one-inch sections stretched across the known universe, it would be 14 billion billion billion inches long, and only one or two of those inches in the middle is the optimal strength-setting for gravity. If you moved the strength-setting to the right or left just a couple of inches, then intelligent life could not exist (though bacterial life might survive with gravity stronger or weaker by one setting up or down).

THE PROBABILITY: Although the force of gravity could obviously have attained a large number of wrong magnitude-ranges, the chance of it being correct for intelligent life to exist, is one chance out of 14 billion billion billion. --Thus, we can conservatively say that it was about one chance out of 1,000,000,000,000,000,000,000 (or 1 out of 10^21, or 1 out of a billion trillions) that the force of gravity might have randomly attained such an advantageous strength for the making of life-necessary elements in the stars.

In a strong-gravity universe, there would not be plants and animals anything like the size of human beings; galaxies, stars and planets would all be much smaller; planets would be more frequently pulled out of their orbits by passing stars, and stars would burn for much less time than they do in our universe. All in all, the prospects for complicated life like ours would not look promising:

Though we perceive gravity to be a ‘strong’ force (because we are close to a very massive body) it is actually incredibly weak in comparison with the electrostatic forces that control atomic structures and, for example, cause protons to repel each other. The factor is of order ~ 10-36. Let us suppose gravity was stronger by a factor of a million. On the small scale, that of atoms and molecules, there would be no difference, but it would be vastly easier to make a gravitationally bound object such as the Sun and planets but whose sizes would be about a billion times smaller. Any galaxies formed in the universe would be very small with tightly packed stars whose interactions would prevent the formation of stable planetary orbits. The tiny stars would burn up their fuel rapidly allowing no time for life to evolve even if there were suitable places for it to arise. Our intelligent life could not have arisen here on Earth if this ration had been even slightly smaller than its observed value. (Morison 2008:327)

Gravity. Gravity is the weakest force in the universe, yet it is in perfect balance. If gravity were any stronger, the smaller stars could not form, and if it were any smaller, the bigger stars could not form and no heavy elements could exist. Only "red dwarf" stars would exist, and these would radiate too feebly to support life on a planet.

All masses are found to attract one another with a force that varies inversely as the square of the separation distance between the masses. That, in brief, is the law of gravity. But where did that "2" [square] come from? Why is the equation exactly "separation distance squared"? Why is it not 1.87, 1.95, 2.001, or 3.378; why is it exactly 2? Every test reveals the force of gravity to be keyed precisely to that 2. Any value other than 2 would lead to an eventual decay of orbits, and the entire universe would destroy itself!

Last edited by Admin on Mon Jan 23, 2017 7:15 am; edited 3 times in total

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One of the striking things about electromagnetism and gravitation is the vast disparity in their relative strengths. In a normal hydrogen atom, the single electron is bound to the single proton by electrical attraction. But another source of attraction is at work here too—gravitation. It is easy to calculate the relative strengths of these two forms of attraction. It turns out that the electrical force is about 10^40 times stronger than the gravitational force. Clearly, then, gravity is extraordinarily weak compared with electromagnetism.

Years ago, Brandon Carter found an amazing relationship between the unexplained ratio 10^40 and the properties of stars. Every star must transport heat from the nuclear furnace in its core to the surface, where it radiates into space. Heat can flow in two ways: by radiation, in which photons convey the energy, and by convection, in which hot gas from deep down rises to the surface, bringing heat with it. Our sun has a convective outer layer, and through a telescope, its surface looks like a boiling maelstrom.Larger stars rely on radiative transfer of heat rather than convection, and this is thought to be important in creating the conditions that lead to supernova explosions. Because both planets and supernovas are a major part of the life story, it is important for the universe to contain a selection of both radiative and convective stars. Carter discovered from the theory of stellar structure that to get both sorts of stars, the ratio of the strengths of the electromagnetic and gravitational forces needs to be very close to the observed value of 10^40. If gravity were a bit stronger, all stars would be radiative and planets might not form; if gravity were somewhat weaker, all stars would be convective and supernovas might never happen. Either way, the prospects for life would be diminished.

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