Quantum vs Virtual - What's the difference?

quantum | virtual |

As nouns the difference between quantum and virtual

is that quantum is while virtual is (computing) in c++, a virtual member function of a class.

As an adjective virtual is

in effect or essence, if not in fact or reality; imitated, simulated.



  • * Burke
  • without authenticating the quantum of the charges
  • * 1749 , (Henry Fielding), Tom Jones , Folio Society 1973, p. 416:
  • The reader will perhaps be curious to know the quantum of this present, but we cannot satisfy his curiosity.
  • *1997 , (Kiran Nagarkar), Cuckold , HarperCollins 2013, p. 375:
  • *:Otherwise I will have given the lie to my maxim that whether you work eight or twenty hours, the quantum of work that gets done on a normal day is the same.
  • * 2008 , The Times of India , 21 May 2008, [http://timesofindia.indiatimes.com/Business/India_Business/Fuel_price_hike_put_off_over_quantum/articleshow/3087364.cms]:
  • The Congress's core ministerial panel on Friday gave its green signal to raising motor fuel prices but the quantum of increase emerged as a hitch.
  • The amount or quantity observably present, or available.
  • *1979 , , Smiley's People , Folio Society 2010, p. 96:
  • *:Each man has only a quantum of compassion, he argued, and mine is used up for the day.
  • * 1999 , Joyce Crick, translating Sigmund Freud, The Interpretation of Dreams , Oxford 2008, p. 34:
  • The dream of flying, according to Strümpell, is the appropriate image used by the psyche to interpret the quantum of stimulus proceeding from the rise and fall of the lungs when the cutaneous sensation of the thorax has simultaneously sunk into unconsciousness.
  • (physics) The smallest possible, and therefore indivisible, unit of a given quantity or quantifiable phenomenon.
  • * 2002 , David C Cassidy et al., Understanding Physics , Birkhauser 2002, p. 602:
  • The quantum of light energy was later called a photon .
  • (math) A definite portion of a manifoldness, limited by a mark or by a boundary.
  • (William Kingdon Clifford)


  • Of a change, sudden or discrete, without intermediate stages.
  • (informal) Of a change, significant.
  • (physics) Involving quanta.
  • * {{quote-magazine, date=2012-01
  • , author=Michael Riordan , title=Tackling Infinity , volume=100, issue=1, page=86 , magazine= citation , passage=Some of the most beautiful and thus appealing physical theories, including quantum' electrodynamics and ' quantum gravity, have been dogged for decades by infinities that erupt when theorists try to prod their calculations into new domains. Getting rid of these nagging infinities has probably occupied far more effort than was spent in originating the theories.}}
  • (computing theory) Relating to a quantum computer.
  • Derived terms

    * quantum algorithm * quantum bit * quantum bogodynamics * quantum brain dynamics * quantum calculus * quantum cascade laser * quantum channel * quantum chaos * quantum chemistry * quantum chromodynamics * quantum circuit * quantum computer * quantum computing * quantum cryptography * quantum darwinism * quantum decoherence * quantum degeneracy * quantum dense coding * quantum dot * quantum effect device * quantum efficiency * quantum electrochemistry * quantum electrodynamics * quantum electronics * quantum entanglement * quantum field theory * quantum fingerprinting * quantum flavordynamics * quantum fluctuation * quantum gate * quantum gauge theory * quantum geometry * quantum gravity * quantum group * quantum gyroscope * quantum Hall effect * quantum harmonic oscillator * quantum heterostructure * quantum history * quantum hydrodynamics * quantum immortality * quantum indeterminacy * quantum inequality * quantum information * quantum jump * quantum leap * quantum level * quantum libet * quantum limit * quantum link * quantum mechanics * quantum network * quantum neural network * quantum number * quantum ontology * quantum operation * quantum optics * quantum phase transition * quantum physics * quantum programming * quantum psychology * quantum randomness * quantum register * quantum scalar field * quantum solvent * quantum sort * quantum state * quantum statistical mechanics * quantum suicide * quantum superposition * quantum teleportation * quantum theory * quantum tomography * quantum valebant * quantum vibration * quantum virtual machine * quantum waveform generator * quantum well * quantum wire * quantum yield * quantum Zeno effect


    Alternative forms

    * vertual (obsolete) * vertuall (qualifier) * virtuall (obsolete)


  • In effect or essence, if not in fact or reality; imitated, simulated.
  • In fact a defeat on the battlefield, Tet was a virtual victory for the North, owing to its effect on public opinion.
    Virtual addressing allows applications to believe that there is much more physical memory than actually exists.
  • * Fleming
  • A thing has a virtual existence when it has all the conditions necessary to its actual existence.
  • * De Quincey
  • to mask by slight differences in the manners a virtual identity in the substance
  • Having the power of acting or of invisible efficacy without the agency of the material or measurable part; potential.
  • * Francis Bacon
  • Heat and cold have a virtual transition, without communication of substance.
  • * Milton
  • Every kind that lives, / Fomented by his virtual power, and warmed.
  • Nearly, almost. (A relatively recent corruption of meaning, attributed to misuse in advertising and media. )
  • The angry peasants were a virtual army as they attacked the castle.
  • * 2012 , Chelsea 6-0 Wolves [http://www.bbc.co.uk/sport/0/football/19632463]
  • The Chelsea captain was a virtual spectator as he was treated to his side's biggest win for almost two years as Stamford Bridge serenaded him with chants of "there's only one England captain," some 48 hours after he announced his retirement from international football.
  • Simulated in a computer or online.
  • The virtual world of his computer game allowed character interaction.
  • Operating by computer or in cyberspace; not physically present.
  • a virtual''' assistant; a '''virtual personal trainer
  • (computing, object-oriented programming, of a class member) Capable of being overridden with a different implementation in a subclass.
  • (physics) Pertaining to particles in temporary existence due to the Heisenberg uncertainty principle.
  • Synonyms

    * de facto


    * de jure * legal * real

    Derived terms

    * virtual reality * virtually


    (en noun)
  • (computing) In C++, a virtual member function of a class.
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