Barbara McClintock: Against The Genetic Grain

The tale of much of Barbara McClintock’s life is that of the scientist working long hours with a microscope seeking to solve mysteries. The mystery she spent most of her career trying to solve was how all cells in an organism can contain the same DNA, and yet divide to produce cells serving different functions; basically how cells differentiate. And for that, she got a Nobel prize all to herself, which is no small feat either.

Becoming a Scientist

Human chromosomes, long strands of DNA
Human chromosomes, long strands of DNA by Steffen Dietzel CC BY-SA 3.0

McClintock was born on June 16, 1902, in Hartford, Connecticut, USA. From age three until beginning school, she lived with her aunt in Brooklyn, New York while her father strove financially to start up a medical practice. She was a solitary and independent-minded child, a trait she later called her “capacity to be alone”.

In 1919, she began her studies at Cornell’s College of Agriculture and took her first course in genetics in 1921. A year later, due to the interest she showed in genetics, she was invited to take the graduate genetics course at Cornell. It was here that she became interested in the new field of cytogenetics, specifically of maize or corn. Cytogenetics studies how the chromosomes relate to cell behavior, particularly during cell division. Chromosomes are the long strands of DNA within the nucleus of every cell and shown here in the photo at a time when they are condensed, or coiled up.

While still at Cornell she developed a number of methods for visualizing and characterizing maize which ended up in textbooks. She also became the first to describe the morphology of the ten maize chromosomes, basically their form and structural relationships, which then allowed her to discover more about the chromosomes. One of her colleagues observed that ten of the seventeen significant advances made in the field at Cornell between 1929 and 1935 were hers. This was only the first step in what would be the remarkable career of a very well respected scientist.

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Maria Goeppert-Mayer: The Other Nobel Prize Winner

Maria Goeppert-Mayer was one of only two women to win the Nobel prize for physics thus far, the other being Marie Curie. And yet her name isn’t anywhere near as well known as Marie Curie’s. She also worked on the Manhattan Project and spent time during her long career with Enrico Fermi, Max Born, Edward Teller, and many other physics luminaries.

She was “other” in another way too. She followed her husband from university to university, and due to prevailing rules against hiring both husband and wife, often had to take a non-faculty position, sometimes even with no salary. Yet being the other, or plus-one, seemed to give her what every pure scientist desires, the freedom to explore. And explore she did, widely. She was always on the cutting edge, and all the time working with the leading luminaries of physics. For a scientist, her story reads like it’s too good to be true, which is what makes it so delightful to read about.

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Rita Levi-Montalcini Had Nerves of Steel

When we think of role models, it’s easy to categorize them narrowly on the basis of their skill set. We might say that he’s a great mathematician, or that she is an excellent chemist. Some role models are admirable on a deeper, human level. These are the kinds of heroes who obliterate all the obstacles dropped in front of them to tirelessly pursue their interests and devote their lives to doing the kind of stuff that makes the world better for everyone.

Italian Nobel Laureate Rita Levi-Montalcini is this kind of role model. Her scientific curiosity and unconventional thinking led her to discover nerve growth factor (NGF), a naturally occurring protein which we now know is responsible for nerve growth and regulation. Rita’s discovery provided great insight into the way the nervous system develops. The discoveries that she made underlie much of modern research into neurologically degenerative diseases like Alzheimer’s and cancer, and NGF is used experimentally the treatment of both.

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Retrotechtacular: The Genesis of the Transistor

Few births are easy. Even fewer result in a Nobel Prize, and hardly any at all are the work of three men. This 1965 film from the AT&T archives is a retrospection on the birth of the transistor nine years after its creators, [Walter Brattain], [John Bardeen], and [William Shockley] received a Nobel Prize in Physics for their discovery and implementation of the transistor effect.

The transistor is the result of the study of semiconductors such as germanium. Prior to the research that led directly to the transistor, it was known that the conductivity of semiconductors increases when their temperature is raised. The converse is true for metals such as tungsten. Semiconductor conductivity also increases when they are exposed to light. Another key to their discovery is that when a metal such as copper is in contact with a semiconductor, conductivity is less in one direction than the other. This particular property was exploited in early radio technology as seen in crystal radios, for copper oxide rectifiers used in telephony, and for microwave radar in WWII.

After WWII, AT&T’s Bell Labs put a lot of time and research into the study of semiconductors, as their properties weren’t fully understood. Researchers focused on the simplest semiconductors, silicon and germanium, and did so in two areas: bulk properties and surface properties. During this time, [Shockley] proposed the field effect, supposing that the electrons near the surface of a semiconductor could be controlled under the influence of an external electric field.

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