From Euclid to Eddington: A Study of Conceptions of the External World

aether algebra angular momentum arithmetic assertion assumed atom axioms axis called century classical physics clock co-ordinates concept constant corresponding curvature definite direction discovery distance earth Eddington effect Einstein world electric charge electromagnetic electron ELLIPTIC GEOMETRY emitted equations Euclid Euclidean geometry Euclidean space existence experiments external world fact fine-structure constant finite frequency fundamental gravitational field idea inertial framework inertial system infinite instant J. J. Thomson light-signal mass material bodies mathematical measured metric molecules motion namely nature nebulae neutron Newtonian non-Euclidean non-Euclidean geometry nucleus observation obtained orbit parallel particles phenomena philosophy physicists plane possible postulate of impotence potential energy Principle of Relativity propagation properties protons pure numbers quantum mechanics quantum number radiation rational regarded relation represented right angles rotation space space-time sphere spin star straight line suppose theoretical theory Timaeus tion triangle universe vector velocity of light vis viva wave-function wave-length waves whole numbers