1. The Anthropic Coincidences

2. The Anthropic Coincidences 1. The existing nuclear forces are essential to the existence of the universe and of life. “The force of nature that cements nuclei together is called the strong nuclear force. Had the strong force been weaker by even as little as 10 percent, it would not have been able to fuse two hydrogen atoms together to make deuterium…(cont’d).

3. .. had the strong force been only a few percent stronger than it is … it would have been too easy for hydrogen nuclei to fuse together The upshot…is that the strong nuclear force has just the right strength: a little stronger or weaker and we would not have been here”

4. 2. All elements have unique energy levels which are critical for development of living systems “Had the energy level of carbon - 12 been only a few percent higher or lower in frequency, the ‘three-alpha’ process would have been out of tune… and without the elements heavier than carbon, life as we know it would have been unable to exist.”

5. 3. The fundament forces of nature have a unique magnitude which supports the chemistry of living systems. “Had the ‘electromagnetic’ forces not been intrinsically much weaker than the strong nuclear force, the electrical energy packed inside a hydrogen nucleus world have been so great as to render it unstable.”

6. 4. The universe is “flat”-- like a pancake --, preserving the universe as a whole. “It turns out that the space of our universe, if looked at on a large enough scale, is on average astonishingly flat …” “Had the flatness of space not been fantastically small to begin with, the universe would either have collapsed and ended a very short time -- a fraction of a second -- after it began or would have undergone such a tremendously rapid expansion that it would have torn matter and even atoms asunder.”

7. 5. Only a three dimensional space allows the present unique mass relations among objects to be maintained. “If the world had not had three dimensions, but four or more, the gravitational force between two objects would have depended in a different way upon the distance between them. And that, in turn, would have made if impossible for planets to orbit stably around stars.”

8. 6. The quantum structure of the atom provides for the “chemistry of life” The orbits of electrons around the atom enable all chemical reactions and life itself. “Had the orbits in atoms not been stable, life based on chemistry would have been impossible.”

9. 7. The Conditions for Earth are Propitious n “If the earth were much smaller, it would not be able to retain an atmosphere.” n “If it were much larger, it would retain a lot of hydrogen in its atmosphere, which might be bad for life.” n “If the earth were much closer to the sun, it would be too hot to have liquid water, if much farther away it would be too cold. “

10. References Quoted passages are from: “Anthropic Coincidences” by Stephen M. Barr in First Things, June/July 2001, Number 114, p17-23.