Where does quantum collide?

In law, the quantum is the amount recoverable: the measured sum a claimant may receive, whether as the reasonable value of services rendered (quantum meruit, meaning 'as much as he deserved') or as the quantum of damages a court awards for a wrong. Blackstone's 1768 Commentaries on the Laws of England recorded the settled rule that where parties fix no price, the law implies a promise to pay as much as the work or goods reasonably deserved. Here the referent is a quantity of legal recovery, argued and assessed case by case, and it has nothing to do with a discrete unit of energy, a slice of processor time, or a sudden change of personality.[7][1]

Unit

A sum of legal recovery, in the money of the judgment

Recovery means

The quantum is itself the amount recovered, fixed by settlement or judgment

Measured by

Argued by the parties and assessed by a court or jury from evidence of value or loss

In physics, a quantum is the smallest discrete amount by which a physical quantity can change: energy, and later action, charge, and other quantities, come in indivisible steps rather than a smooth continuum. Planck's 1901 Ueber das Gesetz der Energieverteilung im Normalspectrum introduced the idea that radiating energy is emitted only in fixed elements proportional to frequency, the discrete packets later named quanta. The referent is a unit of nature's own granularity, fixed by physical constants, not an amount of money a court awards, a share of a computer's time, or a turning point in a life.[2]

Unit

A single discrete step of a physical quantity, such as one energy element hf

Recovery means

Not applicable

Measured by

Inferred from spectra and thresholds, and set by fundamental constants such as Planck's constant

In computing, the quantum is the fixed slice of processor time a scheduler grants a process before interrupting it and moving to the next: in round-robin scheduling, the size of this time quantum sets how responsive and how efficient the system is. Corbató, Merwin-Daggett, and Daley's 1962 An experimental time-sharing system built a scheduler that handed each program a bounded quantum of processor time in turn, and Kleinrock's 1964 Analysis of a time-shared processor gave the queueing theory of how quantum size trades off waiting time. The referent is a tunable interval of computing time, chosen by system designers, and it is unrelated to a legal amount, a physical unit of energy, or a psychological transformation.[3][4]

Unit

One bounded interval of processor time granted to a process

Recovery means

Not applicable

Measured by

Set by the operating system as a configurable time slice, in milliseconds, and studied by queueing analysis

In psychology, a quantum change is a sudden, distinct, and lasting transformation of a person's outlook, values, or behavior, often experienced as arriving all at once rather than through gradual effort. Miller and C'de Baca's 1994 chapter Quantum change: Toward a psychology of transformation named the phenomenon, and Miller's 2004 The phenomenon of quantum change set out its features from interview studies. The referent is a qualitative shift in a whole person, described from self-report, and it bears no relation to a discrete unit of energy, a legal amount, or a scheduler's time slice.[5][6]

Unit

One discrete, self-reported episode of transformation in a person

Recovery means

Not applicable

Measured by

Documented through retrospective interviews and self-report of the change and its aftermath