Money

Neal Stephenson is obsessed with money. I'm reading the Confusion right now, and as always, Eliza is trying to figure out what money is in order to learn how to get more of it.

It's one of those subjects that I just don't get. What exactly backs a US Federal Reserve Note?
I still can't figure that one out.

Originlly, the dollar was 24.06 g Ag or 1.60 g Au.
Then it was 1.5 g Au. Then 0.89 g Au. Then 0.82 g Au.
Now it's a piece of paper that can be taken to the loacal tavern and traded for alcohol. Good enough for me, I suppose.

UPDATE 2004-08-11: Also note that the ratio of the dime to quarter is 10/25. Why? They were both originally siver coins, like the dollar itself. They were worth exactly thier weight in silver.