Lyman Spitzer Jr (1914-97) Singular State - That Is, with an Infinite Central Density (Spitzer, L

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a stellar system to inexorably approach a Lyman Spitzer Jr (1914-97) singular state - that is, with an infinite central density (Spitzer, L. Dynamical Astrophysicist and mission by calculating Evolution ofGlobular Clusters (Princeton - on the night of the Univ. Press, Princeton, NJ, 1987)). founder of controlled scheduled launch Spitzer's seminal contributions to space nuclear fusion research -the focus astronomy are known to schoolchildren corrections IMAGE and curious adults throughout the world. Lyman Spitzer, who died on 31 March, due to the In 1946, he proposed the development of shaped four different fields of science. His bending of UNAVAILABLE FOR large space telescopes in a report called theoretical work on star clusters, the support- COPYRIGHT Astronomical Advantages of an Extra interstellar matter and laboratory plasmas structure on REASONS Terrestrial Observatory. He outlined the is classic. He proposed, helped to design Earth and advantages to be gained from greater and nurtured the construction of the the angular resolution (overcoming the Hubble Space Telescope. And he proposed refraction 'seeing' problems caused by the turbulent a method to control thermonuclear fusion caused by a atmosphere), from the increased for energy production in a magnetic field, beamofhot wavelength coverage available, and from and led a pioneering effort to do so at air present in the test environment. the stability of a low-gravity environment. Princeton University. The Copernicus mission showed that These goals have guided generations of Spitzer was born in Toledo, Ohio, the much of the matter in space is in the space scientists and engineers, and have led son of a businessman. At Yale he was previously unobserved form of hydrogen to a succession of revolutionary discoveries drawn to physics, and went to Cambridge molecules. It also showed that most of the made in space. University to study astrophysics. Later, at heavy elements are bound up in interstellar The large space telescope that Spitzer Princeton, he studied with Henry Norris dust grains, and that one component of the proposed in 1946, eventually called the Russell, then the dean of American medium had the unexpectedly high Hubble Space Telescope, was launched in astronomy, and while a postdoctoral fellow temperature of about a million degrees - 1990, with Spitzer and his family observing at Harvard in 1938-39, he met the rising unexpected, that is, by those who had not the event. In the years between 1946 and young astrophysicist Martin read Spitzer's prediction in 1956 of a hot 1990, and indeed afterwards, Spitzer Schwarzschild* and they became lifelong gaseous corona of the galaxy, analogous to provided gentle but perceptive scientific, close friends. that of the Sun. Finally, deuterium atoms technical and political guidance that Spitzer undertook underwater sound were observed for the first time in helped lead to the extraordinary successes research for the Navy in the Second World interstellar space, with an abundance that of the Hubble Telescope. The modest and War, after which he returned briefly to implies that we are living in an open somewh·at humorous way he regarded his Yale. It was there that he received the offer, Universe - unless there is a huge amount own eminence is typified by a remark he in 1947, to succeed Russell at Princeton. of dark matter in space. once made to Bahcall in the 1970s during Recruiting Schwarzschild as a colleague, he Spitzer, together with H. Alfven and a one of their innumerable trips in support remained at Princeton as director of the few other visionary pioneers, established ofwhat was to become the Hubble Space observatory until 1979, and as professor the theoretical foundations of plasma Telescope: "You know, all the objectives of until 1982. physics in the 1950s. Recognizing the this trip would be fulfilled and much effort In the 1940s, convinced that stars must importance of the thermal, electrical and and money would be saved if they would be forming even today from the clouds of mechanical transport coefficients in a fully just allow us, instead of appearing directly, gas and dust that had been observed in ionized gas, Spitzer made the initial to send wax images of ourselves." interstellar space, Spitzer resolved to calculations of their values, and also the Together with Martin Schwarzschild, understand how. He conceived of an first computations of containment, Spitzer established in Princeton an ultraviolet telescope in orbit, which could resistive heating and diffusion losses for a enduring cordial atmosphere of mutual measure the spectra of atoms and plasma confined in a torus. (The electrical support and encouragement for molecules in interstellar space. In parallel, conductivity of a fully ionized gas is still astrophysical research at the highest level. he worked on the theory of the heating and called the Spitzer conductivity.) This On the day of his death, Spitzer worked a cooling of interstellar gases, and their work was summarized in his book Physics full day in his beloved Peyton Hall, talking response to the pressure of hot regions ofFully Ionized Gases (WIiey, New enthusiastically to colleagues and making near luminous stars. His investigations York, 1962). progress on a research paper. established the study of interstellar matter In 1951, Spitzer proposed to the Atomic He was admired and loved by all who as an independent and rich discipline, Energy Commission the building of a knew him, non-scientists and scientists summarized in his books Diffuse Matter in reactor, which he called a 'stellarator', that alike. He once confessed to one of us that, Space (Wiley, New York, 1968) and Physical would be "designed to obtain power from "I suppose I have at least one serious fault Processes in the Interstellar Medium the thermonuclear reactions between as a scientist: I love to work on big (WIiey, New York, 1978). deuterium and either deuterium or problems''. But he not only worked on big His proposal for an orbiting telescope to tritium'~ The idea came to him on a ski problems, he solved them. study interstellar material was finally slope. Until 1967 he directed the resulting George B. Reid & John N. Bahcall achieved with the launch of the Copernicus programme, Project Matterhorn (later the George B. Field is at the Harvard-S111it/1so11ian satellite in 1972. When a pre-launch test of Princeton Plasma Physics Laboratory), Center for Astrophysics, 60 Garden Street, the focusing mechanism revealed a failure and steady progress was made towards the Cambridge, Massachusetts 02138, USA. John N. in a crucial component, Spitzer saved the goal of controlled thermonuclear fusion. Bahca/1 is in the lllstitute for Advanced Study, a.Martin Schwanschild died on 10 April. An obituar)'will appear In stellar dynamics, Spitzer helped School of Natural Sciences, Princeton, New jersey here shortly. show how the process of 'relaxation' causes 08540, USA.