IT is interesting to learn from L. Essen's communication 1 that the accuracy of measurement of frequencies in the 9,000 Mc./s. region attained at the National Physical Laboratory with existing ...

The aether was the invisible material thought to permeate all the empty space in the universe, used by famous thinkers from Aristotle to Isaac Newton to explain the mysteries of the natural world. The ...

As the 19th century came to a close, physicists were feeling pretty satisfied with the state of their science. The great edifice of physical theory seemed complete. A few minor experiments remained to ...

ALTHOUGH all experiments of the type of the Michelson experiment (with the exception of Miller's experiment) have shown that the second-order effects predicted by classical (non-relativistic) optics ...