UAF Physics Department § Journal Club

In 1930 Robert John Strutt , aka 4th Baron Rayleigh, published a paper entitled “Absolute Intenisty of the Aurora Line in the Night Sky, and the number of Atomic Transitions Required to Maintain it.” This work was both precise and accurate and because of this Don Hunten (U. Saskatchewan) Franklin Roach (National Bureau of Standards) and Joseph Chamberlain (Yerkes) proposed in 1956 that the measure of extended atomic and molecular emissions in aeronomy (and astronomy, to a lesser extent) be measured by a surface brightness unit of a mega-photon per cm^2 (column) per second, and that this unit be named a rayleigh, or R. That definition has stuck in Aeronomy and Auroral physics. In this presentation I’ll discuss Strutt’s measurements and the history leading up to them, and will touch on, among other things, 1) the mystery of the auroral green line prior to 1925, 2) doing aeronomy research without the convenience of silicon diodes and transistors, 3) the quaintness of late 19th and early 20th century scientific literature, and 4) the utility of the rayleigh.


	ABSTRACT In 1930 Robert John Strutt , aka 4th Baron Rayleigh, published a paper entitled “Absolute Intenisty of the Aurora Line in the Night Sky, and the number of Atomic Transitions Required to Maintain it.” This work was both precise and accurate and because of this Don Hunten (U. Saskatchewan) Franklin Roach (National Bureau of Standards) and Joseph Chamberlain (Yerkes) proposed in 1956 that the measure of extended atomic and molecular emissions in aeronomy (and astronomy, to a lesser extent) be measured by a surface brightness unit of a mega-photon per cm^2 (column) per second, and that this unit be named a rayleigh, or R. That definition has stuck in Aeronomy and Auroral physics. In this presentation I’ll discuss Strutt’s measurements and the history leading up to them, and will touch on, among other things, 1) the mystery of the auroral green line prior to 1925, 2) doing aeronomy research without the convenience of silicon diodes and transistors, 3) the quaintness of late 19th and early 20th century scientific literature, and 4) the utility of the rayleigh.

	Friday, 8 April 2016
	Globe Room, Elvey Building
	3:45 PM