Engineers at Purdue University have developed a paint so white that it actually cools surfaces. They hope that the new paint can help fight global warming by reducing reliance on air conditioning. “If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts,” Xiulin Ruan, a Purdue professor of mechanical engineering, said in a statement.