Mathematics and Physics Glossary

Damp, v.t. (Phys.) To decrease the amplitude of a wave.

Dasymeter n. (Phys.) An instrument for testing the density of gases, consisting of a thin glass globe, which is weighed in the gas or gases, and then in an atmosphere of known density.

Datum n.; pl. Data

1. (Math.) The quantities or relations which are assumed to be given in any problem.

2. (Stat.) the complete set of individual pieces of information which is being used in any of the processes connected with statistics.

Daughter, n. (Phys.) The immediate product of the radioactive decay of an element.

Deadbeat a. (Phys.) Making a beat without recoil; giving indications by a single beat or excursion; said of galvanometers and other instruments in which the needle or index moves to the extent of its deflection and stops with little or no further oscillation.

Debuscope n. [From the inventor, Debus, a French optician] (Opt.) A modification of the kaleidoscope; used to reflect images so as to form beautiful designs.