Dr. Norman Borlaug, agronomist and Nobel Peace Prize winner, is dead at 95. By developing strains of wheat and rice that could grow much more densely, he helped Mexico and South Asia increase crop yields by staggering margins, and in turn saved more lives than any other person in the 20th century. The Times has written a lovely obituary; it reminds me that science is a force for optimism and can help us solve the problems that we ourselves create.