Cosmo

The Cosmic Cookbook entry for an inflationary universe, on the other hand, looks as simple as meringue. In this case, the natural starting time would be the onset of inflation -- just a fraction of a second after the Big Bang. In contrast to the standard big bang recipe, the inflationary version calls for only a single ingredient: a region of false vacuum (see "The False Vacuum," page 56). And the region need not be very large. A patch of false vacuum 10-26 centimeter across might be all the recipe demands. While the mass required for the previous recipe was 1032 solar masses, the mass in this case is only an ounce: about the mass of a slice of bread. So, in the inflationary theory the universe evolves from essentially nothing at all, which is why I frequently refer to it as the ultimate free lunch. Does this mean that the laws of physics truly enable us to create a new universe at will? If we tried to carry out this recipe, unfortunately, we would immediately encounter an annoying snag: Because a sphere of false vacuum 10[sup -26] centimeter across has a mass of one ounce, its density is a phenomenal 10[sup 80] grams per cubic centimeter. For comparison, the density of water is 1 gram per cubic centimeter, and even the density of an atomic nucleus is only 10[sup 15] grams per cubic centimeter. If the mass of the entire observed universe were compressed to false-vacuum density, it would fit in a volume smaller than an atom. The mass density of a false vacuum is not only beyond the range of present technology, it is beyond the range of any conceivable technology. As a practical matter, therefore, I would not recommend buying stock in a company that intends to market do-it-yourself universe kits. Nevertheless, I will dismiss the gargantuan mass density of the false vacuum as a mere engineering problem, boldly assuming that some civilization in the distant, unforeseeable future will be capable of creating such densities.