DESC: This dense answer to its own question examines the forces at work on financial markets, what creates them, and when investors can expect another collapse. Sornette, a UCLA professor of geophysics, brings his scientific expertise to bear on the markets, offering up a host of charts, graphs, and figures to illustrate his comprehensive theory of market volatility. WHY STOCK MARKETS CRASH looks not only to science, but also history as Sornette back-tests his theory on some of the great bubble bursts of the last 500 years, exploring what caused them and what we gain by understanding them.