We don't need no stinkin' extra dimensions

I get emailed a "Reason to Believe" from Hugh Ross's organization two or three times a week. Often they are related to biology--junk DNA, molecular motors, etc.--things that I know nothing about and don't find particularly interesting. But today they sent one that I really liked:

Recent gravitational tests further buttress the claim that a supernatural Creator designed the universe to support life. Theoretical work to unify the gravitational force with the other three fundamental forces appears to require the existence of extra dimensions. However, atoms, solar systems, and galaxies are unstable if the size of the extra dimensions is too large. Physicists applied experimental tests using a sensitive type of balance to determine the size of the dimensions. The tests confirmed that the extra dimensions must be smaller than 44 millionths of a centimeter. These results verify the fine-tuning inherent in the universe by demonstrating that the extra dimensions (if they exist) are small enough to not disrupt the stability of atoms, solar systems, galaxies, or other structures on which life depends.

D. J. Kapner et al., "Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scale," Physical Review Letters 98 (2007): 021101.

(From Today's Reason To Believe, 2/27/07, see the Reasons To Believe website.)

This is fascinating stuff. In a nutshell, String Theory suggests that there are more dimensions than our familiar three (three not counting time, that is.) The extra dimensions are microscopically compact; from an extremely early point in the universe's history they have not been expanding as have the familiar three.

Three (no more, no less) macroscopic dimensions give us inverse square laws for gravitation and electricity and magnetism. Inverse square laws are absolutely necessary for gravitational and atomic stability. In other words, it's a darn good thing that those other dimensions, if they exist, decided to remain compact. Not just for life as we know it: any kind of life would require atomic and gravitational stability.

These must have been amazingly difficult experiments, using a torsion balance to test the inverse square law down to 55 μm.

Here is an article with some more information about these tests.

I don't always agree with Ross, but I like him. No mincing words about who the designer is. Love ID or hate ID, you have to give Ross credit for being more honest that Dembski, Wells, and the usual cast and crew of the badly listing steamship ID-Is-Science.