Scientists Born in April

Marie-Sophie Germain (April 1, 1776) was a French mathematician; her main contributions were in acoustics, elasticity and theory of numbers. She became interested in mathematics early in life by reading books in her father’s library. From the beginning her career, Germain’s interest centered on the theory of numbers. Due to her gender she had to use a pseudo name to obtain lecture notes for the Ecole Polytechnique in Paris and to interact with some distinguish mathematicians like Gauss, Fourier, and Legendre. In spite of her isolation from the scientific community and having to go anonymously, she won a prize for the mathematical explanation of the phenomena exhibited by vibrating plates. Later Germain went back to the study of the theory of numbers working on a general solution for Fermat’s last theorem that said that there is no solution for Xn + Yn =Zn if n is an integer bigger than 2 and x, y, and z are non-zero. Germain proved that there is a solution if n is a prime smaller than 100 and x, y, and z are all primes. Her solution was used as basis to prove other areas of Fermat’s last theorem.

William Harvey (April 1, 1578) was an English physician and the first scientist to study and provide experimental evidence for animal blood circulation. His book “Anatomical Exercise on the Motion of Heart and Blood in animals” was his key contribution to science. Harvey showed that the blood flows through the entire body by a single system of arteries and veins. It was thought that the blood used two circulation paths, one for red (oxygenated) blood using the arteries and one for the purple (non-oxygenated) blood running along the veins. His many experiments showed not only how blood is pumped around the body, in a continuous circulation, Harvey also demonstrated other anatomical details such as the role of vein valves in maintaining unidirectional blood circulation. He accurately described the hearth structure and described how the heart propelled the blood in a circular course around the body. He was the personal physician of James I and Charles kings of England.

James D. Watson (April 6, 1928) is an American Geneticist and Biophysicist how shared the 1962 Nobel Prize in Physiology with Francis Crick and Maurice Wilkins for determining the three dimensional structure of DNA. Watson was interested in structural biology and obtained his doctoral degree with work the effects of X-rays on bacteriophage multiplication. He moved to Europe and ended up at Cambridge University where he meet Crick and Wilkins. He then focused his efforts to determine the DNA structure by analyzing the possible stereo-chemical configurations of polynucleotides but the critical piece of information that allowed the determination of the three dimensional structure od DNA was Rosalind Franklin’s X-ray crystallography data. This great achievement has been critical for our understanding of how the double helix structure and hydrogen pairing between bases allows for replication of the DNA message during replication. After Watson moved back to the USA and work in several institutions, Watson became director of Cold Spring Harbor Laboratories were he promoted the study of tumor virology. Work done under his direction spurred our understanding of the molecular basis of cancer biology and specially the role of oncogenes, genes that promote cancer. Later in his career he was a strong supporter of sequencing the human genome. Watson received many honors and awards and wrote many books include Molecular Biology of the Gene (1965), The Double Helix (1968), and The DNA Story (1981).

Melvin Calvin (April 8, 1911) was an American chemist that won the novel Prize in Chemistry in 1961 for his work on photosynthesis, and the elucidation of the Calvin Cycle. Calvin started his work as a chemist but during his college and graduate training he took an interdisciplinary approach by taking courses in other scientific areas like civil engineering, mineralogy, and paleontology. He joined Berkeley as a chemist where he was very prolific investigator. Calvin researched the electronic structure of organic molecules, worked on molecular genetics, oxygen-producing apparatus from cobalt complexes, extraction and purification of plutonium from uranium, and the elucidation of the chemical factors of Rh blood group system. Later Calvin expanded his interests into biochemistry specially the study of photosynthesis. He was the first scientist to use radioactive carbon to identify chemical components that allowed him to piece together biochemical reactions and thus elucidate a pathway. Using isotopic tracing techniques and chromatography he identified the chemical components of the biochemical pathway that convert CO2 into sugars or as is now called the Calvin Cycle. He was a prolific writer of articles and books and founded an interdisciplinary research laboratory called the Calvin laboratory.

Rita Levi-Montalcini (April 22, 1909) was an Italian Neurobiologist. She started her career in Medicine and also did research on the effects that peripheral tissues have on the nervous system. After the Second World War she moved to Washington University in the USA where she continued working in neurobiology. Moltalcini discovered that implanting mouse tumor into chick embryos, promoted nerve tissue growth. She expanded her research and in conjunction with Stanley Cohen they isolate NGF (nerve-growth factor) from the tumor. For this work both won the 1986 Nobel Prize for Physiology or Medicine. NGF plays a crucial role in the growth of nerve cells and nerve fibers of the peripheral nervous system. Montalcini was awarded the National Medal of Science and in Italy was appointed senator for life for her contributions to science.

Robert Oppenheimer (April 22, 1904) was a prominent American Theoretical Physicist, he made many scientific contribution, he had an excellent education at Harvard where he did very well in physics and chemistry, he move to England to work in atomic research at Cambridge University under Lord Rutherford. Oppenheimer then went to the University of Gottingen to work in his doctoral degree with Niels Bohr and P Dirac. He come p with the Bohr-Oppenheimer conjecture were the movement of the neutrons in the nucleus could be treated separately from that of the electrons. This will form the basis for his later work on developing the atomic bomb. Back in the USA he work in the University of California and started working on energy processes of subatomic particles. While there the Second World War broke, because of his brilliance and expertise in atomic research he was appointed director of The Alamos laboratory. He work n the separation of Uranium-235 form natural Uranium and as director of the Manhattan project his task was to harness nuclear power in order to make the atomic bomb. After the war finished with the detonation of the two atomic bombs in Japan, there were plans to make a hydrogen bomb. Oppenheimer opposed this idea, perhaps the deaths of so many people weight on his consciousness. Because of this and his old affiliations with left leaning people, was label disloyal and dismissed from his post. He received the Enrico Fermi Award of the atomic Energy Commission.

Max Planck (April 23, 1858) was a German theoretical physicist. He won the Nobel Prize in 1918 for his work on developing the quantum theory. His work shed light into the atomic and subatomic world. This led him to discover the Planck radiation Law and its famous constant that explain black body radiation. The Planck constant is a fundamental physical constant important in quantum mechanics because describes the behavior of particles and waves on the atomic level.