Number ten in a series of anthropic 'coincidences' that allow intelligent life to exist.

"The charges of the electron and proton have been measured in the laboratory and have been fond to be precisely equal and opposite. Were it not for this fact, the resulting charge imblance would force every object in the universe--our bodies, trees, planets, suns--to explode violently. The cosmos would consist solely of a uniform and tenuous mixture not so very different from air." George Greenstein, THE SYMBIOTIC UNIVERSE.

From the same book.

"Neither of the two balls attracts me, however, nor any other electrically charged neutral object. Because my body is literally flooded with electric charges--indeed, it's built of them--it has only one way of maintaining this immunity by containing equal numbers of each kind of charge. If say, one hundred protons are to be found in my fingertip, one hundred electrons will also be found there. That balance is inherent in the nature of matter. The plus just cancels the minus, adding up nicely to zero.

"THat is the balance, or rather, half of it.

"It ishalf because in order for matter to remain electrically neutral in this way, the charges of the electrons must exactly balance that of the protons. These charges have been measured experimentally and it was found that they do. But what would the universe have been like if they were not?

"If the electron carried more charge than the proton, the cancellation would no longer be perfect. Objects would still contain equal numbers of each particle but the charges would no longer add up to zero. Rather, they would add up to a net minus. Every objects in the universe would be charged negatively--and like charges repel one another. The table in the corner would repel the lamp upon it; the tree outside the window, the car parked beneath..."

(Deleted due to space considerations)

"Its strength would depend on the degree to which the charges of the electron and the proton differed; small differences, small repulsion. On the other hand, so powerful are electrical forces in general, and so enormous are the numbers of subatomic particles within even the smallest of objects, that even very small forces would lead to very great forces. A mere 1 percent offset between the charges of the electron and that of the porton would lead to a catastrophic repulsion. My arms would not just extent outward; they rip from my body, blast away from the Earth, and fly off into space."

(Deleted due to space considerations.)

"No....1 percent is too great a discrepency. How precise must the balance be? How accurately must the charge of the elctron be matched with that of the proton before such disasters can be avoided? The question is easy to asnwer--a good high-school student could do it---but the result one obtains is impressive. Relatively small things like stones, people. and the like would fly apart if the two charges differed by as little as one part in 100 BILLION. Large structures like the Earth and the Sun require for their existence a yet more perfect balance of ONE PART IN A BILLION BILLION."