In quantum mechanics, a particular property of a substance — electrical conductivity, say, or optical transparency or reflectivity — corresponds to the average or “expectation value” of an observable quantity.
Alchemy Arrives in a Burst of Light|Philip Ball|September 30, 2020|Quanta Magazine
According to some calculations, the cosmos might have cooled so quickly that the fabric of space-time became fractured, creating a network of whisper-thin tubes filled by pure energy that stretch across the breadth of the observable universe.
Some Physicists See Signs of Cosmic Strings From the Big Bang|Thomas Lewton|September 29, 2020|Quanta Magazine
In terms of the quality of the pitches they make — as measured by observable factors such as velocity and movement — southpaws are simply not in the same league as righties.
What Really Gives Left-Handed Pitchers Their Edge?|Guy Molyneux|August 17, 2020|FiveThirtyEight
All ISIS logistics and dispositions in the field are observable by drone and satellite.
How a Real Air War Could Demolish ISIS|Clive Irving|August 23, 2014|DAILY BEAST
Theory: a scientifically acceptable principle explaining a set of observable facts.
What's Wrong With Republicans?||November 9, 2012|DAILY BEAST
Global warming is an observable fact, and transportation emissions are the second largest contributor to the problem.
Pancakes' New Topper|Stacey Slate|December 8, 2009|DAILY BEAST
How has this soldier demonstrated recurring actions, patterns, or observable behaviors that might indicate his real beliefs?
Why We Should Screen Muslim Soldiers|Ken Allard|November 27, 2009|DAILY BEAST
To a human, out there in the street, the scent was not observable.
Lad: A Dog|Albert Payson Terhune
Observable, only, that Hotham and Dubourgay sat silent in the tripudiation; with faces diplomatically grave.
History Of Friedrich II. of Prussia, Vol. VII. (of XXI.)|Thomas Carlyle
This is observable in his relations as an official, and as a teacher, and in his dealings on matters of religion.
Life Of Mozart, Vol. 1 (of 3)|Otto Jahn
Now it is observable that these three have no personal references, and that the two which part them have.
The Expositor's Bible: The Psalms, Vol. 1|A. Maclaren
In order to obtain an observable fact, I would not have hesitated laying myself open to ridicule.
A measurable property of a physical system, such as mass or momentum. In quantum mechanics, observables correspond to mathematical operators used in the calculation of measurable quantities. Operators that do not commute, having a nonzero commutator, correspond to observables that cannot be precisely measured at the same time, such as momentum and position. See also uncertainty principle.