As we brace ourselves for 2021, let’s take a look back at the last 100 years of science history.
100 Years Ago (1921)
Chemical engineer Thomas Midgley, during his research for General Motors, discovered that adding chemical called tetraethyl lead to gasoline could improve fuel efficiency and prevent engine knocking. Tetraethyl lead became a common fuel additive for most of the 20th century, until regulators realized that cars running on leaded gasoline were pumping fine particles of lead into the air and causing environmental damage and health problems. Most countries banned leaded gasoline in the 1990s or early 2000s.
Orthopedic surgeon Frederick Banting isolated a hormone called insulin, which is secreted by cells in the pancreas called islets. Insulin helps regulate the amount of sugar in the blood. After several more years of work, researchers – especially biochemist James Collip – developed ways to mass produce insulin and purify it enough to make a safe and effective treatment for diabetes. Getting there involved animal experiments that would horrify modern ethicists, clinical trials, and reportedly at least one fistfight between Banting and Collip.
Astronaut John Glenn, the first American to orbit the Earth, was born on July 18, 1921.
Astronomer Henrietta Leavitt, who discovered a way to use the brightness of variable stars – stars that brighten and dim at regular intervals – to calculate the distance between galaxies and other distant objects in space, died on December 12.
75 Years Ago (1946)
Astronaut Ellison Onizuka, who died in the 1986 explosion of the space shuttle Challenger, was born on June 24, 1946. Physicist Shirley Ann Jackson, president of the Rensselaer Polytechnic Institute and the first African-American woman awarded a doctorate from MIT, was born on August 5, 1946.
Science fiction author H.G. Wells died on August 13, 1946.
50 Years Ago (1971)
Apollo 14 became the third crewed mission to land on the Moon in February; a few months later, Apollo 15 and its crew landed with the first lunar rover.
Early in 1971, the first personal computer, the Kenbak-1, went on sale. Only 50 were ever built, and they came out several months before the world’s first microprocessor, Intel’s 4004, which released in November 1971. IBM released the first floppy disks – big 8-inch wide versions – the same year. And computer programmer Ray Tomlinson sent the first real email on the Department of Defense’s ARPANET computer network, a precursor of the modern internet. The format he used for the first email addresses, “username@computername” hasn’t changed much in 50 years. Ebooks are also a 50-year-old concept; Project Gutenburg founder Michael S. Hart uploaded the first one to the University of Illinois at Urbana-Champaign’s mainframe in November 1971. It was a copy of the Declaration of Independence.
Doctors at London’s Atkinson Morley Hospital X-ray did the first x-ray computed tomography (CT) scan on a patient to get a better look at a cerebral cyst.
Inventor and CEO Elon Musk was born on June 28, 1971. Astrophysicist Sara Seager was born on July 21, 1971.
Inventor Philo T. Farnsworth, who invented several components of the earliest TV sets and built the first all-electronic television, died on March 11, 1971.
25 Years Ago (1996)
Dolly the Sheep, the first successfully cloned mammal, was born on July 5, 1996.
Astronomer and science communicator Carl Sagan died on December 20, 1996.