Jonathon Keats is an artist-philosopher whose conceptual projects have examined everything from the nature of the divine (he tried to engineer God in a petri dish) to the sexuality of plants (he built a pornography theater for them). While Keats's projects are often both whimsical and beautiful on the outside, at their center are deep questions about the nature of life and the universe. In short, it is conceptual art that actually makes you think about concepts, rather than merely about conceptual art.His latest piece is the First Bank of Antimatter, a financial institution that will issue a new currency backed not by gold or silver, but by antimatter, in the form of positrons created from the radioactive decay of a block of potassium fluoride. "We've confused money, which essentially is a means of transaction, with what is transacted," says Keats. "Therefore, we have come to place value on money on its own right as if it were one of the things transacted." The positrons that back the bank's currency are annihilated when they come into contact with matter, and can only exist in the material world for an instant except under controlled conditions. Since the money could never actually be exchanged for the thing that gives it value, positron notes help to distinguish between our mode of currency and the things we buy with that currency (the blurring of that line led to many of our current financial woes). "It can only really be used for purposes of transaction," he says. "Think of it as something to be hoarded or think of it as something that is valuable in its own right, and-by the laws of nature-antimatter will refute this idea."The First Bank of Antimatter will offer notes in 10,000, 100,000, and 1 million positron denominations, at an initial exchange rate of $10 for 10,000 positrons, starting November 12 at the Modernism Gallery in San Francisco.