January 30 marks the passing of John Bardeen. Bardeen was an American physicist who contributed to the understanding of solid-state physics enough to earn two Nobel Prizes.
The first was while he was working at Bell Labs. AT&T needed to upgrade their nationwide telephone system. People were making more and more telephone calls and the vacuum tube transistors could not keep up with their needs. Vacuum tubes are large, hot, unreliable, power hungry and could not operate at the ultra-high frequencies needed to carry several telephone conversations at once.
Bardeen, William Shockley, and Walter Brattain were given the task of finding a way to replace vacuum tubes. Shockley designed a semiconducting amplifier made up of a small cylinder coated with silicon mounted near a metal plate that did not work as designed. Bardeen and Brattain performed several experiments to find out why the device did not work. They eventually changed the silicon coating to germanium oxide and pushed gold contact points very close together into the germanium. This produced an amplification across all frequencies, but good amplification in some frequencies. To get the contacts closer together, they coated a plastic triangle with a gold ribbon and cut one of the tips. When they pressed the plastic into to the germanium and put current through one side, amplified current came out the other contact and it worked on all signal frequencies. This was the first successful semiconducting junction transistor.
Their device would go on to revolutionize the electronics industry. Their transistor was smaller, cheaper, and operated at lower voltages than the vacuum tubes they replaced. It’s been called the most significant invention of the 20th Century and earned all three the 1956 Nobel Prize in Physics.
Bardeen left Bell Labs to research how and why their transistor worked. He focused on the behavior of electrons when two different metals meet and how metals conduct better when cold. This led him to study superconductivity. Together with Leon Cooper and John Schrieffer, they came up with the first microscopic theory of how superconductivity works. They called their theory BCS theory using their initials. BCS theory helped understand the physics of electron interactions at low temperatures and earned the three men the 1972 Nobel Prize in Physics.
This award made Bardeen the first to win two Nobel Prizes in the same field and one of the four people who received more than one Nobel Prize. The other three people are Marie Curie, Linus Pauling, and Frederick Sanger
Notable Science History Events for January 30
1991 – John Bardeen died.
1949 – Peter Agre was born.
Agre is an American biologist and physician who discovered aquaporins. Aquaporins, or water channels, are proteins that transport water between cells through the phospholipid bilayer. Agre discovered these proteins by accident. He was researching the Rh blood group antigens and tried to isolate the Rh molecule. He found a second molecule in the mix that no known function. Once he determined the role of this molecule, he knew he had something important. This discovery would earn him the 2003 Nobel Prize in Chemistry.
1948 – Orville Wright died.
Orville was the younger of the Wright brothers who were the first to accomplish controlled and sustained powered flight. Their aircraft used three axes of control to maintain steady flight: pitch, yaw, and roll which is the standard control for planes to this day.
Orville was the pilot of the first powered flight on December 17, 1903. He flew for 12 seconds and traveled 120 feet reaching a speed of just under 7 miles per hour.
1928 – Johannes Fibiger died.
Fibiger was a Danish doctor who was awarded the 1926 Nobel Prize in Medicine for discovering that Spiroptera carcinoma caused cancer in laboratory mice and rats. This work was considered groundbreaking since it showed outside stimuli caused cancerous tumors.
It was later determined that the parasite didn’t cause the tumors, but tissue damage. Two years after Fibiger won his Nobel Prize, Japanese scientist, Katsusaburo Yamagiwa successfully induced carcinoma in rabbit ears by painting them with coal tar.
1899 – Max Theiler was born.
Theiler a South African/American virologist who was awarded the 1951 Nobel Prize in Medicine for his work on yellow fever. Theiler and Hugh Smith developed a vaccine for yellow fever just in time for an epidemic in West Africa. The Rockefeller Foundation distributed 28 million doses of this vaccine in 7 years that effectively eliminated the disease.
Theiler contracted yellow fever while pursuing his vaccine. Fortunately, he survived and gained the immunity surviving the disease grants.