Definitions

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a relativistic quantum theory of the electromagnetic interactions of photons and electrons and muons

Etymologies

Sorry, no etymologies found.

Support

Help support Wordnik (and make this page ad-free) by adopting the word qed.

Examples

Comments

Log in or sign up to get involved in the conversation. It's quick and easy.

  • "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."

    "But," says Man, "the Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED."

    "Oh dear," says God, "I hadn't though of that" and promply vanishes in a puff of logic.

    --Douglas Adams (THGTG)

    January 21, 2007

  • quod erat demonstrandum

    January 21, 2007

  • Isn't a knowledge of Latin a wonderful thing?

    January 21, 2007

  • Q.E.D. is an abbreviation of the Latin phrase "quod erat demonstrandum" which means literally, "that which was to be demonstrated", written in its abbreviated form at the end of a mathematical proof or philosophical argument. Latin translation of the original Greek ὅπε�? ἔδει δειξαι (hoper edei deixai) which was used by many early mathematicians including Euclid and Archimedes.

    October 10, 2008

  • Q.E.D. = because Euclid says so.

    "Yes, we can take the liberty to draw that line and make that circle, no I haven't proven it yet, but we're going to do so because I say so..."

    October 12, 2009

  • Absolutely not. Euclid only uses Q.E.D. when he has finished proving something. If he wants you to assume something he will use the language "Let there be a...", and pull out something either from a previous proposition, or from his definitions, postulates, and common notions.

    October 12, 2009