Accidents happen all the time. People become distracted and drop items from their hands, clumsily knock things off shelves, and misinterpret kitchen recipes that sometimes produce disastrous results. While everyone suffers from clumsiness or preoccupation now and then, inventors, chemists, and engineers typically do everything they can to prevent accidents on the job. As they develop ideas they believe could possibly change the world - for better or worse - experts meticulously calculate their every move to ensure they can replicate the results, should they succeed.