plural of parasol beech

A curved mirror with a reflecting surface that forms part of a paraboloid (as opposed to, for example, a sphere)

A reflector with a curved reflecting surface that forms part of a paraboloid (as opposed to, for example, a sphere)

A paradox of choice in which people's decisions produce inconsistencies with subjective expected utility theory.

A choice problem designed to show an inconsistency of actual observed choices with the predictions of expected utility theory.

plural of paradise crane

Synonym of blue crane

A hypothetical problem dealing with the notion of infinity. Given an empty vase and an infinite supply of balls, an infinite number of steps are performed, such that at each step 10 balls are added to the vase and one ball removed from it. The question is then posed: how many balls are in the vase when the task is finished?

(philosophy) Any of a set of philosophical problems generally thought to have been devised by the Greek philosopher Zeno of Elea (c. 490–430 BC) to support Parmenides' doctrine that, contrary to the evidence of one's senses, the belief in plurality and change is mistaken, and in particular that motion is nothing but an illusion.

(philosophy) A philosophical problem whereby a man intends to walk a mile from a particular point, but an infinity of gods separately plan to obstruct him. One of them will raise a barrier to stop his further advance if he reaches the half-mile point, a second if he reaches the quarter-mile point, a third if he goes one-eighth of a mile, and so on ad infinitum. The paradox involves the fact that (i) the man cannot begin walking, because a barrier will stop him even at the shortest distance, but (ii) if he does not begin walking, no barrier will rise.