The ID Report

by Denyse O'Leary
ARN correspondent

In Why the Universe Is the Way It Is, astronomer Hugh Ross explains,

The solar system holds a special position in the Milky Way, close to (but not exactly at) the co-rotation distance - the one distance from the core where stars orbit the galaxy at the same rate as its spiral arm structure does. A star or planetary system located at the co-rotation distance and between two spiral arms would seemingly remain at that safe place. However, stars and planetary systems exactly at the co-rotation distance would experience a "mean motion resonance," repeated gravitational "kicks" exerted by the galactic arm structure. Such kicks would send the star and its possible planetary system flying out of the habitable zone.

Earth's solar system is located just inside the co-rotation distance. So it is safe from the mean motion resonance. Because the solar system revolves around the galactic center only slightly faster than the galactic arm structure, it crosses the spiral arms only one about every billion years. The last spiral arm crossing occurred 560 to 600 million years ago (just before the Cambrian explosion, when complex animals first came on the scene), so Earth currently resides in the safest possible position).

This protected location is truly exceptional. Not all spiral galaxies are like the Milky Way. In the vast majority, the co-rotation distance and the habitable zone fail to overlap. Not only is there a match for the Milky Way Galaxy, but also the best possible place for a newly forming planetary system to accumulate all the heavy elements and long-lived radioactive isotopes requires for advanced life happens to lie just inside the co-rotation distance." (pp. 68-70)

See also: "Astronomer argues that we can test whether Earth is fine tuned as a science lab"

Also, just up at Colliding Universes a blog about competing theories of our universe:

Physics: No escape from philosophy through equations?

Extraterrestrials: Several million UFO reports later ... the state of the question

More demolition teams trying to blow up the Big Bang

Do you have time to hear about some new theories ... of time?

Now, if the butterflies would just appear out of nowhere ...

Chaos theorists stumped by butterfly effect?

Solar system: Ours is special, researchers say

Aussie PM: Cosmic order proves God exists

Origin of life: Ah, that "just so happens" series of intermediate chemical steps ..

Physicist realizes that there is more to nature than materialist atheism can explain

Rehabilitating the idea of creation - Big Bang cosmology

Toronto-based Canadian journalist Denyse O'Leary (www.designorchance.com) is the author of the multiple award-winning By Design or by Chance? (Augsburg Fortress 2004), an overview of the intelligent design controversy. She was named CBA Canada's Recommended Author of the Year in 2005 and is co-author, with Montreal neuroscientist Mario Beauregard, of The Spiritual Brain: A neuroscientist's case for the existence of the soul (Harper 2007).