Sunday, May 30, 2010

Hannes Alfven


Hannes Olof Gosta Alfven was born on May 30, 1908 in Norrkorping, Sweden. His parents, Johannes and Anna-Clara Alfven were both practicing physicians, his mother being one of the first women in Sweden to practice medicine. Alfven recorded that one of the events that kindled his interest in astronomy and astrophysics was his receiving at an early age the gift of a popular book on astronomy by French astronomer Camille Flammarion. The other was his membership in his school's radio club. As part of club activities young Alfven built radio receivers and without a nearby radio station in Norrkorping, and the one in Stockholm to faint to be received, Alfven was thrilled to hear the notes of music coming out the atmospheric noise and identifying as coming from Aberdeen, Scotland.

After high school Alfven entered the University of Upsala where he studied mathematics, theoretical and experimental physics. He went on to complete his doctorate at Upsala, doing his dissertation on "ultra-short electromagnetic waves". At a time when many others were studying nuclear physics, Alfven demonstrated his independent thought by going on to study electronics and astronomy. After finishing his doctorate in 1934, Alfven remained at the University of Upsala as a lecturer in physics. In 1937 he became a research physicist at the Nobel Institute. In 1940 he was appointed Professor of the Theory of Electricity at the Royal Institute of Technology. He was appointed Professor of Electronics in 1945 and Professor of Plasma Physics in 1963. In 1967 he moved to the University of California at San Diego as a visiting professor.

In 1933, as a graduate student, Alfven published a theory of the origin of cosmic rays in Nature. The term cosmic ray is a misnomer. Cosmic rays are particles (almost 90% of them are protons) that travel through space. In 1937 Alfven proposed that there was a galactic electromagnetic field that caused cosmic rays to move in spiral patterns and because of this they are observed as coming from all directions. He argued that if plasma pervaded the galaxy and the plasma carried an electrical charge, it would create a magnetic field pervading the galaxy. At the time Alfven's suggestion of a galaxy wide magnetic field was dismissed, and it was not until 1950s that the electromagnetic acceleration of cosmic rays was accepted and it was not observed until the 1970s.

For most of Alfven's career because of his unorthodox ideas he was forced to publish in journals without large circulations. Interplanetary space was largely thought to be a good vacuum, disturbed only by occasional comets. This view was largely accepted because it looked that way when viewed by telescopes which only observe in the visual region of the electromagnetic spectrum. Alfven's proposal of electromagnetic currents could not be observed and thus they were dismissed.

Alfven's most well known discovery was the discovery of Alfven waves, proposed in a 1942 paper in Nature. Alfven waves, in plasma, are oscillations of ions and the magnetic field. At first Alfven's proposal was discounted and it was not until after a seminar given by Alfven in 1948 at the University of Chicago with the famous physicist Enrico Fermi in the audience, after which Fermi was seen to nod his head and heard to remark "of course", that Alfven waves were accepted. Alfven was awarded the Nobel Prize in Physics in 1970 "for fundamental work and discoveries in magnetohydrodynamics with fruitful applications in different parts of physics".

Other awards won by Alfven include the the Gold Medal from the British Royal Astronomical Society in 1967, the Franklin Medal from The Franklin Institute in 1970, the Lomonosov Medal from the USSR Academy of sciences in 1971, and the Bowie Medal awarded by the American Geophysical Union in 1988. The European Physical Society awards the Hannes Alfven Prize annually for outstanding contributions to plasma physics.

Alfven retired in 1991 and returned to his native Sweden.

Alfven died on April 2, 1995.



References:

Falthammer, Carl-Gunne;"Hannes Alfven" at the European Geophysical Society website (www.egu.eu)

Falthammer, C-G. and Dessler, A.J.; "Hannes Alfven" at alfvenlab.kth.se

Hogan, James P.; "Kicking the Sacred Cow"; Bean Books, 2004

Perrat, Anthony; "Dean of Plasma Dissidents"; The World and I (1988)p.190-197 found online at public.lanl.gov

Hannes Alfven Nobel Biography

Hannes Alfven Wikipedia Entry

Sunday, May 23, 2010

John Bardeen


John Bardeen was born of May 23, 1908 in Madison, Wisconsin, the second son of the son of Charles Russell Bardeen, the dean of the University of Wisconsin medical school and Althea Harmer Bardeen. Brilliant at an early age his parents moved him from third grade to junior high. When Bardeen was 12 his mother became seriously ill with cancer, and although his father downplayed the seriousness of the illness to his children Althea Bardeen died. Bardeen seriously affected by the death of his mother barely passed French that year. Despite the set back Bardeen graduated high school in 1923 and that fall entered the University of Wisconsin, to major in electrical engineering, at the age of 15.

Bardeen graduated with a B.S. in electrical engineering in 1928, after taking a semester off to work at the Western Electric Company in Chicago. Having already completed some of the coursework Bardeen stayed on at the University of Wisconsin to earn a M.S. in electrical engineering studying the emerging field of electrically prospecting for oil under Leo J. Peters. He chose to stay in electrical engineering because it had the math that he loved but unlike physics there were better job prospects and because he did not want to become an academic like his father. By the time he graduated the depression had struck and job prospects were scarce. After being rejected by Bell Labs, Bardeen was able to get a job at Gulf Research Laboratories again working under Peters developing ways to study magnetic and gravitational surveys to find oil.

Geology did not really interest Bardeen and after three years he applied and was accepted to the graduate program in mathematics at Princeton University starting in 1933. At Princeton Bardeen studied both physics and mathematics, completing a thesis on solid state physics under Nobel Laureate Eugene Wigner. Before completing his thesis Bardeen was accepted as junior fellow of the Society of Fellows at Harvard University. Bardeen spent three years at Harvard working on problems cohesion and electrical conduction in metals and he also did some work on level density of nuclei. Bardeen graduated with a Ph.D. in mathematical physics from Princeton in 1936.

In 1938 Bardeen accepted a position as an assistant professor at the University of Minnesota. In 1941, with America involved in WWII, Bardeen worked as a civilian physicist at the Naval Ordinance Laboratories helping the Navy develop ways for ships and submarines to avoid magnetic mines and torpedoes. He was offered a position working for the Manhattan Project, but refused.

Bardeen had met William Shockley while he was at Harvard. After the war Shockley offered Bardeen a position in his research group at Bell Labs at twice the salary of his professorship in Minnesota. Bardeen joined Shockley and Walter Brattain working on an solid state alternative to the vacuum tube amplifiers that were used in electronic devices. In the spring of 1947 Shockley assigned Bardeen and Brattain the task of determining why the silicon amplifier (which was later changed to germanium) he had designed was not working. Drawing on his training in quantum mechanics Bardeen realized that electrons behaved differently at the germanium surface than in the interior. If they could control what was happening on the surface it would allow them to control the current. It took until the end of 1947 for them to perfect their device which was the first point-contact transistor.

A transistor is a semiconductor device used to amplify and switch electronic currents. A transistor changes the amount of power in an electric current. Transistors are ubiquitous in modern electronic devices. Shockley seeing the potential of the new devices continued working on them, excluding Bardeen from further research. Bardeen, upset that he was not able to continue his research, left Bell Labs for a professorship at the University of Illinois. Bardeen, Brattain, and Shockley were awarded the Nobel Prize in 1956 "for their researches in semiconductors and their discovery of the transistor effect". Bardeen was making breakfast when he heard the news of the Nobel Prize win on the radio and he dropped a frying pan he was using spreading eggs across the kitchen floor. Bardeen brought only three of his five children (two of his sons were in school at Harvard) to the Nobel Prize ceremony, and when scolded by King Gustav, he assured the king he would bring them all the next time.

At the University of Illinois Bardeen was happy because now he could research whatever he wanted. At Illinois Bardeen studied superconductivity, the ability of some materials (usually at very low temperatures) to conduct electrons without resistance. Working with Leon Cooper and graduate student John Robert Schrieffer he developed a theory of superconductivity called BCS theory (an acronym for their last names). BCS theory proposes that at low temperatures electrons condense into Cooper pairs which have some of the properties of bosons through interaction with the crystal lattice. As a single electron travels through a lattice it creates a small positive charge in the material through which it travels, which attracts a second electron. If the attraction between these two electrons is greater than the vibrational energy of the lattice, forcing them apart, they remain paired. Because the vibrational energy is proportional to temperature this explains why low temperatures are required for superconductivity. So the first electron pulls the second electron through the lattice creating superconductivity. Bardeen, Cooper and Schrieffer were awarded the Nobel Prize for physics in 1972 for their work on superconductivity. Bardeen was the first person to win two Nobel Prizes in the same field and he brought all of his children to the second ceremony.

Bardeen died on January 30, 1991.


References:

Barry, TJ, "BCS Theory" at ffden-2.phys.uaf.edu

Hoddeston, Lillian and Daitch, Vickie ; True Genius: The Life and Science of John Bardeen; Joseph Henry Press; 2002


John Bardeen Nobel Biography

John Bardeen Wikipedia Entry

Sunday, May 16, 2010

Johannes von Mikulicz-Radecki


Johanes von Mikulicz-Radecki was born in Czernowitz (in what was then Austria and is now Poland) on May 16, 1850. His father was an architect and his mother was a member of the Prussian nobility. His ability with languages was early evident and as a youth he spoke fluent German and Polish, and had a facility for Russian. He did his undergraduate studies at Hermannstadt and was headed for a career in law when, against his father's wishes he turned to medicine. Mikulicz went to the University of Vienna to study medicine. His father was so upset with his son that he refused to pay for his studies and Mikulicz taught piano and played organ in a church every morning from 5 to 8 a.m. to pay for his studies. He finished his M.D. in 1875.

After graduation he worked as volunteer assistant to Theodor Billroth, a surgery professor the University of Vienna. After three years his became Billroth's regular assistant. In 1880 he qualified as Privatdozent (unpaid tutor) and took charge of the surgical department at the Allgemeinen Polyklinik (general outpatient clinic) in Vienna. While there he improved the models of the esophagoscope and gastroscope by including distal illumination allowing the surgeon to better visualize the interior of these organs. In 1882 he became the director of the Surgical Clinic of Krakow. In 1887 he accepted the position as director and professor of surgery at the Surgical Clinic of Konigsburg. He remained there for three years and then became the professor of surgery at Breslau in 1890. He remained there until his death.

Mikulicz did much to improve surgical techniques used operating on the digestive system. While at Krakow he was the first surgeon to suture a perforated gastric ulcer and surgically restore part of the esophagus after tumor resection. An ardent advocate of Joseph Lister's work using antiseptics he used a gauze mask during surgery and was one of the first surgeons to wear sterile cotton gloves during surgery.

An imperturbable surgeon one of his assistants recorded a story about an emergency laprotomy performed on a particularly stormy day. While preparing for the surgery one of the glass windows on the roof of the surgical clinic shattered raining pieces of glass down, one nearly missing Mikulicz. Mikulicz calmly turned to the his assistant and asked him to prepare the patient.

Mikulicz died on Jun 14, 1905.


References:

Olch, Peter D.;"Johan von Mikulicz-Radecki"; Annals of Surgery (1960)152:923-926

Young, Archibald; "Obiturary: Dr. Johannes von Mikulicz-Radeki"; Glasgow Medical Journal (1905)64:110-115

Jan Mikulicz-Radecki Wikipedia Article

Sunday, May 9, 2010

Carl Gustaf Patrik de Laval


Carl Gustaf Patrik de Laval was born on May 9, 1845 in Blosenberg, Sweden to a family of soldiers whose French ancestor had ridden with Gustavus Adolphus. At eighteen he entered the technical department of the University of Upsala, graduating three years later. His first position was as a draftsman at the Stora Kopparberg Company, but his health forced to give up the confining position for something with more opportunities for exercise. He returned to the University of Upsala for further study, graduating in 1872 with Ph.D. in Chemistry.

In 1875 he took a job as an engineer at Klosterverken Iron Works and shortly thereafter he developed a centrifugal device for separating cream. Needing more time to perfect his device he resigned his position at Klosterverken, and after much persistence was able to obtain a small loan that enabled him to manufacture his device. The device proved to be such a success that it was not long before Separator Company, Limited was on secure financial footing. For his invention of this separator device and other labor saving devices for dairy farmers, de Laval has been called "the Edison of dairying".

In search of a method to drive the centrifugal separator, which required high speeds, de Laval developed a steam turbine. The turbine was driven by high pressure steam shooting through a cone shaped nozzle developed by de Laval, that is now used on rocket engines. Able to turn, at what at the time was a frightening speed of 24,000 rpm, the turbine had to be reduced to one-tenth speed to drive the separator and did not prove to be useful for this purpose. However there were many other uses for the turbine and a separate industry developed.

Not content to rest on his laurels de Laval was constantly seeking new inventions, including milking machines and a process for treating low grade Swedish zinc ores, none of which were as successful as his cream separator. During his lifetime he received many honors, including from the King of Sweden, the Cross of Commander of the Order of Wasa and that of Knight in the Order of the North Star and he was made a member of the Royal Swedish Academy of Sciences in 1886 and received its gold medal in 1892.

De Laval died on February 2, 1913.


References:

"Karl Gustaf Patrik de Laval" from the Journal of the American Society of Mechanical Engineers (1913) Vol. 35, Issue 1, p 16-18

"Inventor of the Separator Dead" from the Holstein-Friesian Register (1913) Vol.35, Part 1, p.692

Gustaf de Laval, Wikipedia Entry

Sunday, May 2, 2010

Jesse William Lazear


Jesse William Lazear was born on May 2, 1866 in Baltimore, Maryland. His early education was obtained at Trinity Hall, a private school in Washington, Pennsylvania and he went to Johns Hopkins University, graduating in 1889. He studied medicine at Columbia University, graduating in 1892. After earning his M.D. he served for two years at Bellvue Hospital in New York City, where he was the first person to ever isolate Neisseria gonorrhoeae the causative bacterium of gonorrhea, in pure culture from a blood sample. After finishing his hospital service he spent a year of study and investigation in Europe, during part of which which he worked at the Pasture Institute in Paris. After his return from Europe he was appointed bacteriologist to the medical staff at Johns Hopkins University and also served as the assistant in clinical microscopy at the university.

In February 1900 Lazear reported to Camp Columbia, Cuba for duty as acting assistant surgeon with the U.S. Army Corps. stationed on the island. There he undertook the study of the tropical diseases, particularly malaria and yellow fever, affecting American troops on the island. In May of 1900 he was appointed to a board, which was headed Walter Reed, commissioned to study yellow fever in Cuba.

Yellow fever is a hemorrhagic viral disease that begins suddenly after an incubation period of three to six days. Symptoms include fever, headache, chills, back ache, loss of appetite, nausea, and vomiting. In about 15% of cases this acute phase if followed by a toxic phase with symptoms of jaundice (due to liver damage), bleeding in the mouth, gastrointestinal tract and eyes. This toxic phase is fatal 20% of the time. There is no treatment for yellow fever, but there is a vaccine. Yellow fever is transmitted by the bite of the yellow fever mosquito (Aedes aegypti) and the tiger mosquito (Aedes albopictus).

While he worked at Johns Hopkins, Lazear had followed the research of Sir Ronald Ross concerning the mosquito vector for the transmission of malaria. This experience allowed Lazear to be open to the theories of Cuban scientist Carlos Juan Finlay, who believed that mosquitoes were the vector for the transmission of yellow fever. By June of 1900 Lazear was culturing mosquitoes, from samples he had obtained from Finlay. The board however, acting under the instructions of Army Surgeon General George Miller Sternberg, had been investigating Bacillus icteroides as the causative agent for yellow fever. This line of research quickly proved to be fruitless and Lazear was well prepared to pursue research using mosquitoes as a vector for the disease.

The project started on August 1, 1900, using the mosquitoes that Lazear had cultured. Recording his experiments in a small pocket notebook, Lazear recorded the work of raising and infecting mosquitoes, and on August 11th to the 31st recording a series of inoculations, the last two of which produced full blown cases of yellow fever, proving that the vector for the disease was a mosquito. Although there is no direct evidence of him purposely infecting himself, his notebook was given to Walter Reed and was lost at the time of Reed's death, Lazear became infected with yellow fever, which would prove fatal.

Lazear died on September 26, 1900.


References:

Kelly, Howard Atwood; Walter Reed and Yellow Fever; McClure, Phillips, and Co.; 1906

"Jesse William Lazear (1866-1900)" at the Philip Hench Walter Reed Yellow Fever Collection at yellowfever.lib.virginia.edu

Yellow Fever wikipedia entry