Description: Twelve years ago, after a decade of development, an unmanned Ariane 5 rocket launched by the European Space Agency exploded just after its first liftoff. The cause of this $500 million firecracker was a software error caused when a 64 bit floating point number relating to the horizontal velocity of the rocket with respect to the platform was erroneously converted to a 16 bit signed integer. Numerical disasters like these are one thread in a lively blog that supports the course "Introduction to Scientific Computing" at Cornell University. "One great thing about scientific computing is that anybody can do it, but that's also a downside since doing things well often involves getting the details right," says the course's professor, Doug James. "It reminds me of Carl-Erik Froberg's famous quote about scientific computing: 'Never in the history of mankind has it been possible to produce so many wrong answers so quickly!'"