Absence of Dispersive Properties of Space for Electromagnetic Radiation Tested to ± 14 x 10^-5; Comments on a Proposal of Softky and Squire

Abstract

In session I 1 of the Berkeley meeting of December 30, 1960, S. D. Softky and R. K. Squire proposed a test for dispersive properties of space for electromagnetic radiation by detonating a nuclear explosive at a distance of 10^6 miles from the earth and noting the arrival times of different types of radiation at detectors above the atmosphere. The purpose of this note is to point out that Softky and Squire have overlooked the fact that a test for the dispersive properties they postulate already exists, covering perhaps not quite as extensive a range of the electromagnetic spectrum as they hope to cover (they claim a factor of 10^11) but nevertheless sufficient to render any such effect extremely unlikely over a range of frequencies of a factor of 5 X 10^9. I refer to a measurement performed in 1950 by means of the bent quartz crystal diffraction spectrometer [1] of the wavelength of the annihilation radiation generated in a block of copper by positrons from the nuclide 64Cu.