His containment strategy helped wipe out the disease in the 1970s, one of the world’s greatest public health triumphs. He also led the C.D.C. and promoted childhood vaccination worldwide.
Rising Arctic temperatures and melting sea ice could be causing cold air to flow into the Northern Hemisphere. But not all scientists agree.
She and her staff at Union Carbide created synthetic materials that improved various industrial processes, including purifying water. She also developed a way to make emeralds.