Read Online Calculating God by Robert J. Sawyer - Free Book Online
Authors: Robert J. Sawyer
Ads: Link
way?” anyway; I thought maybe he knew something I didn’t—and indeed, to my shock, that was precisely the case.
“Your science knows of four fundamental forces; there are actually five, but you have not yet discovered the fifth. The four forces you know about are gravitation, electromagnetism, the weak nuclear force, and the strong nuclear force; the fifth force is a repulsive one that operates over extremely long distances. The strengths of these forces have wildly varying values, and yet if the values were even slightly different from their current ones, the universe as we know it would not exist, and life could never have formed. Take gravity as an example: were it only somewhat stronger, the universe would have long since collapsed. If it were somewhat weaker, stars and planets never could have coalesced.”
“ ‘Somewhat,’ ” I echoed.
“For those two scenarios, yes; I am talking about a few orders of magnitude. You wish a better example? Very well. Stars, of course, must strike a balance between the gravitational force of their own mass, which tries to make them collapse, and the electromagnetic force of their own outpouring of light and heat. There is only a narrow range of values in which these forces are in sufficient equilibrium to allow a star to exist. At one extreme blue giants are produced, and at the other red dwarfs form—neither of which are conducive to the origin of life. Fortunately, almost all stars fall in between those two types—specifically because of an apparent numerical coincidence in the values of the fundamental constants in nature. If, for instance, the strength of gravity were different by one part in—give me a second; I must convert to your decimal system—by one part in 10 40 , this numerical coincidence would be disrupted, and every star in the universe would be either a blue giant or a red dwarf; no yellow suns would exist to shine down on Earthlike worlds.”
“Really? Just one part in ten to the fortieth?”
“Yes. Likewise the value of the strong nuclear force, which holds the nucleuses of atoms together even though the positively charged protons try to repel each other: if that force were only slightly weaker than it actually is, atoms would never form—the repulsion of protons would keep them from doing so. And if it were only slightly stronger than it actually is, the only atom that could exist would be hydrogen. Either way, we would have a universe devoid of stars and life and planets.”
“So you’re saying someone chose these values?”
“Exactly.”
“How do you know that these aren’t the only values those constants could possibly have?” I said. “Maybe they are simply that way because they couldn’t possibly be anything else.”
The alien’s round torso bobbed. “An interesting conjecture. But our physicists have proved that other values are indeed theoretically possible. And the odds of the current values arising by chance are one in the number six followed by so many zeros that if you could engrave a zero on each neutron and proton in the entire universe, you could still not write out the number in full.”
I nodded; I’d heard variations on all this before. It was time to play my trump card. “Maybe all the possible values for those constants do exist,” I said, “but in different universes. Maybe there are a limitless number of parallel universes, all of which are devoid of life because their physical parameters don’t allow it. If that’s the case, there’s nothing remarkable about us being in this universe, given that it’s the only one out of all the possible universes that we could be in.”
“Ah,” said Hollus. “I see . . .”
I folded my arms smugly.
“I see,” continued the alien, “the source of your misunderstanding. In the past, the scientists of my world were mostly atheists or agnostics. We have long known of the apparently finely tuned forces that govern our universe; I form the impression that you were
“Your science knows of four fundamental forces; there are actually five, but you have not yet discovered the fifth. The four forces you know about are gravitation, electromagnetism, the weak nuclear force, and the strong nuclear force; the fifth force is a repulsive one that operates over extremely long distances. The strengths of these forces have wildly varying values, and yet if the values were even slightly different from their current ones, the universe as we know it would not exist, and life could never have formed. Take gravity as an example: were it only somewhat stronger, the universe would have long since collapsed. If it were somewhat weaker, stars and planets never could have coalesced.”
“ ‘Somewhat,’ ” I echoed.
“For those two scenarios, yes; I am talking about a few orders of magnitude. You wish a better example? Very well. Stars, of course, must strike a balance between the gravitational force of their own mass, which tries to make them collapse, and the electromagnetic force of their own outpouring of light and heat. There is only a narrow range of values in which these forces are in sufficient equilibrium to allow a star to exist. At one extreme blue giants are produced, and at the other red dwarfs form—neither of which are conducive to the origin of life. Fortunately, almost all stars fall in between those two types—specifically because of an apparent numerical coincidence in the values of the fundamental constants in nature. If, for instance, the strength of gravity were different by one part in—give me a second; I must convert to your decimal system—by one part in 10 40 , this numerical coincidence would be disrupted, and every star in the universe would be either a blue giant or a red dwarf; no yellow suns would exist to shine down on Earthlike worlds.”
“Really? Just one part in ten to the fortieth?”
“Yes. Likewise the value of the strong nuclear force, which holds the nucleuses of atoms together even though the positively charged protons try to repel each other: if that force were only slightly weaker than it actually is, atoms would never form—the repulsion of protons would keep them from doing so. And if it were only slightly stronger than it actually is, the only atom that could exist would be hydrogen. Either way, we would have a universe devoid of stars and life and planets.”
“So you’re saying someone chose these values?”
“Exactly.”
“How do you know that these aren’t the only values those constants could possibly have?” I said. “Maybe they are simply that way because they couldn’t possibly be anything else.”
The alien’s round torso bobbed. “An interesting conjecture. But our physicists have proved that other values are indeed theoretically possible. And the odds of the current values arising by chance are one in the number six followed by so many zeros that if you could engrave a zero on each neutron and proton in the entire universe, you could still not write out the number in full.”
I nodded; I’d heard variations on all this before. It was time to play my trump card. “Maybe all the possible values for those constants do exist,” I said, “but in different universes. Maybe there are a limitless number of parallel universes, all of which are devoid of life because their physical parameters don’t allow it. If that’s the case, there’s nothing remarkable about us being in this universe, given that it’s the only one out of all the possible universes that we could be in.”
“Ah,” said Hollus. “I see . . .”
I folded my arms smugly.
“I see,” continued the alien, “the source of your misunderstanding. In the past, the scientists of my world were mostly atheists or agnostics. We have long known of the apparently finely tuned forces that govern our universe; I form the impression that you were
Similar Books
