Modern successor to arithmomancy, embodying the belief that numbers can explain the workings of the universe and thus allow predictions to be made.
Odic Force
Fundamental force in nature claimed to have been discovered by Carl von Reichenbach in the mid-19th century, but now widely recognised as pseudoscience.
Organotherapy
Technique that makes use of extracts derived from animal or human tissues to treat medical conditions.
Orgone
Widely discredited theory of universal life energy developed by the Austrian psychiatrist Wilhelm Reich (1897–1957).
Orgonomy
Redirected to orgone.
Oxgang
Old measurement of land. eight oxgangs equals one carucate or ploughland. One oxgang is the area that could be ploughed by a team of eight oxen in one year.
Pedrail Wheel
Type of all-terrain wheel developed in the late 19th and early 20th centuries by Bramah Joseph Diplock.
Perfect number
A perfect number is a positive integer the sum of whose proper divisors is equal to the number itself.
Phantasmascope
Redirected to phenakistoscope.
Phenakistoscope
Optical toy producing the illusion of moving images, popular during the Victorian era.