Agricultural Research Policy

Abstract

From Galileo's measurement of time by musical beats at about half-second intervals to modern atomic clocks, progressively more accurate instruments have been developed and are here reviewed. Both the mechanical and the pendulum clock were major advances and led to theories of a clocklike universe in the 17th century. Barrow, Newton and Leibniz treated time as mathematical concepts and in the 19th century time as a linear advancement became accepted as evolutionary biology extended the vision of time to millions of years. In modern physics, Einstein's special relativity introduced 'time dilation', an idea somewhat contrary to our common sense intuition but now supported by abundant empirical evidence.