Donald Thorn Farley Jr. (October 26, 1933 – May 13, 2018) was an American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

and Professor of Engineering at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

who pioneered the use of radar

remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth ...

of the earth's

ionosphere The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an ...

. He developed the theory and technique of

incoherent scatter Incoherent scattering is a type of scattering phenomenon in physics. The term is most commonly used when referring to the scattering of an electromagnetic wave (usually light or radio frequency) by random fluctuations in a gas of particles (most o ...

observation of the thermal fluctuations of

plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood pla ...

. About 80 percent of all ionospheric radio scientists in the United States who practice incoherent scatter were trained by Farley, or by his students. Farley was the J. Preston Levis Professor of Engineering at

. His principal collaborators included John Dougherty,

Tor Hagfors Tor Hagfors (18 December 1930 – 17 January 2007) was a Norwegian scientist, radio astronomer, radar expert and a pioneer in the studies of the interactions between electromagnetic waves and plasma. In the early 1960s he was one of a handful o ...

, Bela Fejer, Ronald Woodman, Michael Kelley, and Wesley Swartz.

References

External links

* {{DEFAULTSORT:Farley, Donald T. 1933 births 2018 deaths American physicists Cornell University alumni Cornell University faculty Scientists from New York City Recipients of the Gold Medal of the Royal Astronomical Society