We've already heard what a billion represents. What about a trillion?
"A billion seconds ago it was 1959; a billion minutes ago Jesus was alive; a billion hours ago our ancestors were living in the Stone Age; A billion days ago no-one walked on the earth on two feet."
"One trillion seconds ago anatomically modern humans were successfuly competing with the last bands of neandertals in ice age Europe; One-trillion minutes ago there were no modern humans at all and fire was still a million years in our hominid ancestors' future; One-trillion hours ago our direct ancestors were rat-like nocturnal insectivores hiding in cozy daytime burrows from allosaurs and raptors; One-trillion days ago there were no animals at all, but bacterial collectives had begun working together in communities that that would one day be called protozoa. And one-trillion years ago ... well there was no one trillion years ago as that would predate the observed beginning of time and space many times over.
Then again we can cram a trillion into much smaller time scales, as in the half a trillion dollar deficit Bush just admitted to, or the multi-trillion dollar war in Iraq based on a false premise, or the trillions in tax cuts and government giveaways to wealthy corporations and trust funds kids that will have to be repaid by hard-working single moms and their children for the next five generations, or the ten trillion dollar national debt almost all of which was racked up under the past three Republican Presidents.
A trillion is vast number, one thousand billion to be exact. For someone raised on the writing of the late Dr. Sagan, with a love for natural history, a billion is something I've had to learn to get my arms around. It took Republicans to teach me what a trillion feels like."