7 scientists who helped change the world

Flossie Wong-Staal (1946-2020), a virologist, played a central role in AIDS research.

Wong-Staal was part of the team that first identified the HIV virus as the cause of AIDS. Together with her colleague Robert Gallo, Wong-Staal cloned HIV and discovered how it hides from the immune system. She also created a blood test to detect HIV.

Christine Darden (1942-present), a female engineer at NASA, used computer models to calculate the environmental effect of sonic booms.

Sonic booms are the loud noises produced when planes fly faster than the speed of sound. The noise is caused by the sudden change in air pressure around the aircraft. While NASA scientists replicated the booms using wind tunnels and model planes, Darden's simulation results matched the wind tunnel outcomes, were cheaper and more efficient.

Charles Drew (1904-1950). Drew was a leading expert on blood.

During World War II, the need for blood transfusions increased. So in 1940, the U.S. formed the Blood for Britain project, aiming to ship blood overseas. Drew was appointed head of the project, and with John Scudder, devised a way to separate plasma from the blood. Blood needs to be refrigerated to remain useful, but if the plasma is extracted from the blood and mixed in a saline solution, it could be shipped without refrigeration.

George Carruthers (1939-2020) designed the Lunar Surface Ultraviolet Camera in 1972.

The camera was sent aboard Apollo 16 and put on the lunar surface. From there, it took over 550 ultraviolet images of stars, nebulas and galaxies. It also gathered data on Earth's atmosphere, including the accumulation of pollutants.

Alice Ball (1892-1916) pioneered a new treatment for leprosy. Leprosy caused nerve damage and skin lesions. In 1873, Norwegian physician Dr Gerhard Henrik Armauer Hansen found that a bacterium Mycobacterium leprae caused leprosy.

In 1915, Ball developed a means to isolate the active ingredient in chaulmoogra nut oil and engineered a water-soluble injection of this extract as an effective treatment. The credit for her method was attributed to her colleague Arthur L. Dean, but she was credited for it posthumously.