Franklin E. Roach

Rayleigh Unit

The Rayleigh Unit is a unit of photon flux used to measure the radiance of air glow, atmospheric phenomena like auroras, and integrated starlight of various forms in space. The Rayleigh Unit was first proposed in 1956 by Donald M. Hunten, Franklin E. Roach, and Joseph W. Chamberlain and named by them for Robert John Strutt, 4th Baron Rayleigh (1875–1947) who first discovered the glow of the night sky. The symbol for the unit is R, also like the unrelated Roentgen unit.

Fulbright Scholar

Franklin Roach spent a year in Paris in 1951-2 on a Fulbright Fellowship investigating night-sky research. Roach also worked with a European pioneer, Daniel Barbier, in this same field.

Encounter with Struve

Roach, who had a gentle personality, worked early in his career with Otto Struve. Struve had an abrasive personality, and spared no words upon his victims. Struve encouraged the removal of the existing Director of Yerkes Observatory and facilitated his own appointment to the same position, despite Frost originally inviting Struve to come to Yerkes when Struve at that time only spoke Russian and was destitute in Turkey and Greece after escaping the Russian Revolution. On July 1, 1932 Struve succeeded Edwin Brant Frost as Director of Yerkes Observatory. Roach, a graduate student at Yerkes in an office on that date, had the following encounter with Struve while measuring a spectogram authorized by the existing Director Frost earlier that morning:

• Version in Yerkes:

Roach: Good morning, Mr. Struve.

Struve: Good morning. What are you doing?
Roach: I'm measuring a spectogram.
Struve: What star is it?
Roach: β Lyrae.
Struve: Who told you to measure that spectogram?
Roach: Mr. Frost did.

Struve: From now on I'll tell you what stars to measure!

• Version in Musings:

S. "What are you doing?"

R. "I'm measuring a spectogram"
S. "What is the star?"
R. "Beta Lyrae"
S. "Who told you to measure it?"
R. "Mr. Frost suggested it."

S. "From now on you do what I say."

Book Contributions

Roach wrote most or contributed in part to several important books. Two elucidating on the subject of airglow would serve as foundation volumes in the field of upper atmosphere science: Aurora and Airglow edited by B. M. McCormac, and The Light of the Night Sky. Another one with a scientific approach to ufology in the early 1970s would serve as a foundation volume for that field of exploratory science: UFO's: A Scientific Debate edited by Carl Sagan and Thornton Page. On the general front, he would write the chapter "Aurora and Airglow" in the Scientific American book The Planet Earth for the popular audience.

The Light of the Night Sky

While still associated with "Rutgers, The State University" in Newark, New Jersey and the University of Hawaii in Honolulu, Hawaii Roach served as the principal author, along with co-author Janet L. Gordon (then working for and associated with the Bernice P. Bishop Museum in Honolulu), in a successful book which served as an important early volume in the series Geophysics and Astrophysics Monographs. Gordon proofread and edited Roach's work, and wrote the historical sections to provide further context. Gordon was married with Roach later in 1977. The volume was published in December 1973 and became the fourth volume in this international series of fundamental monograph textbooks on the subjects of geophysics and astrophysics.

Roach's and Gordon's volume was entitled The Light of the Night Sky and dealt with the subject of the composition of the lighted sky itself in the topical subject area "the light of the night sky" (LONS). It gave scientific presentations with a fundamental overview of the atmospheric processes and interstellar physics involved, especially on Earth's nightside. The preface was prepared in August 1973 and Roach was still writing later chapters in September. Topics discussed included the dark adaptation of the eye, star counts and the distribution of starlight over the sky, the polarization of the "Zodiacal Light", and the study of "The Gegenschein".

Further discussions concerned whether the night-glow was a static or dynamic phenomena, the sources or causes of night-glow, the photochemical reactions in Earth's upper atmosphere, the appearance of the night-glow from space in Earth's exosphere and geocorona. The book also dealt with the polar aurora, auroral arcs, the varying brightness of the "Night-glow Layer" depending on zenithal distance, dust-scattered starlight, the diffuse galactic light, dust in the interplanetary and interstellar environment concerning the "Zodiacal Dust Cloud", and interstellar dust. The text ended with a summation concerning the cosmic light between galaxies and the contemplative topic of cosmology.

Awards

Becoming a world authority in auroral studies and airglow, Franklin travelled to Washington, D.C. in early 1961 to be honored as the recipient of the Gold Medal of the U.S. Department of Commerce for his "outstanding contribution to upper atmosphere physics by means of studies of optical emission from the night sky". Franklin had been nominated for the award by Gordon Little. The award was bestowed to him by Luther H. Hodges, the 15th United States Secretary of Commerce who had just completed his second term as Governor of North Carolina.

Legacy

Memorial Scholarship

Franklin E. Roach Memorial Scholarship, University of Arizona.

Archives

Following Roach's passing his papers were archived in 1994 in Alaska upon the recommendation of Bob Eklund (Robert L. Eklund) (associated with Mount Wilson Observatory) to Donald Osterbrock who made arrangements:

• Franklin E. Roach Papers, Archives, Alaska and Polar Regions Department, Collections Section, Elmer E. Rasmuson Library, University of Alaska, Fairbanks, Alaska.