The observation that the French suffer a relatively low incidence of coronary heart disease, despite having a diet relatively rich in saturated fats.

Pseudis paradoxa, a species of frog unusual because it is larger as a tadpole (up to 25 cm or 10 in. long) than as an adult (about a quarter of that length).

plural of grandfather paradox

plural of bootstrap paradox

A time travel paradox in which the consequences of an event in the future travel back in time and cause an event in the past or present, which in turn is among the causes of the first event, forming a causal loop in which each event is caused by the other.

The paradox of time travel in which inconsistencies emerge through changing the past.

(rare) The statistical and psychological observation that a person is prone to prefer Coca-Cola over Pepsi when they have labels, but prone to prefer Pepsi over Coca-Cola when they are unlabelled.

Removal of one's clothes while in a state of hypothermia.

The proposition in hydrostatics that any quantity of water, however small, may be made to counterbalance any weight, however great; or the law of the equality of pressure of fluids in all directions.

(topology) The non-intuitive fact that it is possible to turn a sphere inside out in a three-dimensional space with possible self-intersections but without creating any crease.