| Edward Robert Harrison | |
|---|---|
| Born | 8 January 1919 London, England |
| Died | 29 January 2007 (aged 88) Tucson, Arizona |
| Residence | Tucson, Arizona (deceased) |
| Nationality | British |
| Fields | Astronomy |
| Institutions | University of Massachusetts University of Arizona NASA |
| Alma mater | Institute of Physics (UK) |
| Known for | Cosmology Harrison-Zel'dovich spectrum Solving Olber's Paradox |
| Notable awards | The 1986 Melcher Award (for religious liberalism) Masks of the Universe |
Edward R. (Ted) Harrison (8 January 1919 - 29 January 2007) [1] was a British astronomer and cosmologist, who spent much of his career at the University of Massachusetts and University of Arizona. He is noted for his work about the increase of fluctuations in the expanding universe, for his explanation of Olber's Paradox, and for his books on cosmology for lay readers. [1] [2] [3]
Contents |
Harrison's education at Sir John Cass Technical Institute was interrupted by World War II (WWII), during which he served for 6 years with the British Army in various military campaigns, eventually serving as Radar Adviser to the Northern Area of the Egyptian Army.[1]
Following WWII, Harrison became a British Civil Servant,[1] at first with the Atomic Energy Research Establishment in Harwell, and later, at the Rutherford High Energy Laboratory. During this time period, he attained the equivalent of university degrees,[1] becoming a graduate, then an Associate, and finally a Fellow of the Institute of Physics. He also became a Fellow of the Royal Astronomical Society, the American Physical Society, and the American Association for the Advancement of Science.
In 1965, Ted Harrison came to the USA as a NAS-NRC[1] Senior Research Associate at the NASA Goddard Space Flight Center, in Maryland. In 1966, he then became one of the three founders[1] of the Astronomy Program within the Department of Physics and Astronomy at the University of Massachusetts Amherst. Over the next 30 years, he influenced the revival of the Five College Astronomy Department, linking UMass to Amherst College, Hampshire College, Smith College, and Mount Holyoke College. He also played a key role in the rise to international prominence of the Five College graduate course in astronomy.[1] At his death, he was emeritus Distinguished University Professor of Physics and Astronomy at UMass,[1] and an adjunct professor at the Steward Observatory of the University of Arizona.[1]
Ted Harrison had broad interests, and he published more than 200 papers, primarily in astrophysics and cosmology, but also in space sciences, high energy physics, plasma physics and physical chemistry.[1] He was an elegant writer with a passion for the history of ideas. His books (cf. especially his text Cosmology) illustrated points of physics or cosmology with many literary, philosophical, and historical references.
His study of structure formation from primordial density perturbations in the cosmic plasma has led to the general use of the term Harrison-Zel'dovich spectrum for primordial random fluctuations characterised by a scale-invariant power spectrum.[4] (The term also honors the Soviet physicist Yakov Borisovich Zel'dovich.)
Harrison was fascinated with Olber's Paradox (the night sky is dark despite the vast number of stars in the universe), and published in 1987 an entire book, Darkness at Night, mulling over the Paradox and its rich history. In 1964, he published detailed calculations that solved the paradox by concluding that stars do not generate enough energy to illuminate the entire sky.[1] Darkness at Night states that this is not primarily because the universe is expanding, but rather because the stars and galaxies have had only about 15 billion years to radiate, and they do not have sufficient energy to keep radiating for much longer.[1][2] Darkness at Night lays out how Harrison discovered that Edgar Allan Poe's essay Eureka anticipated this conclusion, and that Lord Kelvin had reached a very similar conclusion in a 1901 article ignored for 80 years until Harrison drew attention to it.[1][2]
Harrison's text Cosmology: The Science of the Universe describes the problem of the cosmic edge of the universe by quoting 5th century BCE soldier-philosopher Archytas, who questioned what occurs as a spear is hurled across the outer boundary of the universe.[1]
His final book, Masks of the Universe (2nd ed., 2003), questions current perceptions of reality, asking whether present cosmology, with ordinary matter, dark matter, plus dark energy, is yet only another "mask" obscuring a Universe which will remain perforce forever unknown to humans.