How Much Is Too Much?

At the beginning of each school year, there is a great push at just about all the grade levels to promote understanding of place value. I have spent the past week trying to wrap my head around that very same concept. Adding zeros to numbers makes them bigger. I get that. But just like fourth graders, there comes a time and a decimal place when my brain just locks up. For fourth graders, it's somewhere in the hundred thousand to million range. For me, it's in the billions.
I took astronomy classes in college and I became familiar with the practice of using scientific notation to describe numbers by powers of ten. It was that tricky little exponent above the ten that could mess you up completely. The distance from the earth to the moon is in the ten to the fourth power neighborhood, and the distance from the earth to the sun is in the ten to the seventh power vicinity. What I found even more useful was the concept of Astronomical Units. Knowing that the distance between the earth and the sun could be described as one Astronomical Unit, I began to use this measurement in as many different impractical ways as possible. For example, what fraction of an astronomical unit is it between here and the nearest 7-11?
When I heard that the government's bailout of the various failing financial institutions was going to cost somewhere close to half a trillion dollars, I found myself searching in vain for some kind of real number that I could start with. Remember, I'm the guy who struggles with a million of something. A "trillion" just seems as made up as Laurie Anderson's "kerjillion," or Dennis the Menace's "lebentyseven." If only this sum could be paid in nickels, then it would be meaningful to me. Take your half trillion and multiply that by twenty. Now that would be a number worth pondering.
Instead, I would like to suggest the following: From now on, just as we have come to do with astronomy, let us now use this half-trillion mark as a single unit. I propose that we now refer to this unit as a "Greenspan" in honor of the man who once rode herd on all those zeros. Now when we say "It's only going to cost the government a Greenspan to cover the fallout of this financial crisis," we can all rest just a little bit easier. But I guess we'd all feel a little better if we didn't have to think about it at all.