More on Fine-Tuning

The way in which the universe expanded after the Big Bang depended critically on how much total mass and energy the universe had, and on the strength of the gravitational constant. Professor Steven Hawking asks: “Why did the universe start out with so nearly the critical rate of expansion that even now, 10 thousand million years later, it is still expanding at nearly the critical rate? If the rate of expansion one second after the Big Bang had been smaller by even one part in 100 thousand million-million, the universe would have re-collapsed before it ever reached its present size.” [A Brief History of Time, 210. ]

In 1966 the astronomer Carl Sagan announced that there were just two important criteria for a planet to support life: The right kind of star, and a planet the right distance from that star. Sagan went on to speculate that with roughly 1 octillion—24 zeroes—planets in the universe, there should have been about a septillion—21 zeroes—planets capable of supporting life.

However, as knowledge of the universe increased, two criteria grew to 10 then 20, then 50, and so the number of potentially life-supporting planets decreased accordingly: to a few thousand planets until the number of possible planets hit zero, and kept going. The odds turned against any planet in the universe supporting life, including this one. Probability says that even we shouldn’t be here.  Today there are more than 200 known parameters necessary for a planet to support life—every single one of which must be perfectly met, or the whole thing falls apart.

Still more on Fine-Tuning next time.  In Christ...