Abstract

The mass-to-volume ratio of the universe is of cosmic importance. It determines whether the universe will expand (as it is presently doing) forever or whether it will eventually recontract to a Big Gnab (the time-reverse of the Big Bang). The Big Bang is somewhat like a cannonball fired from a large Jules-Vern-style cannon on the surface of an airless planet. There is a "magic" cannonball speed called the escape velocity which measures whether its velocity "bank balance" exceeds the gravitational "debt" which must be paid to escape the planet's gravity well. If the cannonball leaves the cannon barrel with a speed greater than escape velocity it will escape the planet's pull; with less than escape velocity it will fall back; with exactly escape velocity it will move ever more slowly away from the planet, requiring an infinite time to escape completely