“Money is a very interesting philosophical idea in that we have all of humanity agreeing on this system,” said Ray Kurzweil. “So even though we may radically disagree on some things — like let’s say the U.S. government and Al Qaeda — they both respect money. So it’s remarkable how we have this universal respect for this very esoteric virtual construct.”

Mr. Kurzweil is not sure how easy it will be for new currencies to emerge. “We’ve built up respect for currencies associated with nations,” he said. “People respect dollars, because of the track record, relative stability.” […]