| Description | He thanks his brother for his papers on gravitation and light, which he found difficult to read but he learned much. If the actual paths of rays near the Sun are straight lines, he asks how Joseph accounts for the displacements of stars in the photographs taken by the Eclipse Expedition. Alexander has attempted to explain this on an enclosed sheet [not present]. He thinks it a defect in discussions around relativity that nothing is mentioned about phase. The velocity of light is not quite definite he thinks, and the structure of a wave surface of light from a moving source is different from a fixed source; the difference would be the basis of connecting relativity with aether theory. Alexander is going to St. Margaret's Portstewart for June and September and has taken another house there for July and August. He describes the location, and Joseph would be welcome at any time. He sees that the Commission on a levy for 'War Wealth' is still active and he discusses the possible impact in capital and shares owned in 1914-1919. In a postscript, he notes his shareholdings in J. Milligen and Company, coal merchants of Belfast. |