Zeno's Paradox & The Quantum Zeno Effect

Thank you for The Great Courses Plus for Supporting PBS. To learn more and try The Great Courses Plus click, http://ow.ly/ORgD30rA2tQ.Uploaded 23-03-21PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACESign Up on Patreon to get access to the Space Time Discord!https://www.patreon.com/pbsspacetime“A moving arrow is at rest.” This is obviously a nonsensical contradiction. But Zeno, a Greek philosopher famous for his metaphysical trolling, devised a paradox whose conclusion is just this. Here’s how it goes: if you look at an arrow flying through the air at any instantaneous snapshot in time, the arrow doesn’t travel any distance. If time is composed of an infinite number of these snapshots, and the arrow doesn’t move in any of them, then the arrow is at rest during the entirety of its flight. The moving arrow is at rest. In fact, if we’re talking about a quantum arrow, there may be a way to freeze its motion simply by looking at it, through the aptly named quantum Zeno effect. The quantum Zeno effect predicts that certain quantum events - like the electrons moving between atomic energy levels, or the decay of atomic nuclei, can be frozen through the simple act of observation. I’m going to tell you about some very real experiments that claim to have demonstrated this phenomenon. But first, let’s see if the quantum Zeno effect can save us from being shot by a quantum arrow.Check out the Space Time Merch Storehttps://www.pbsspacetime.comSign up for the mailing list to get episode notifications and hear special announcements!https://mailchi.mp/1a6eb8f2717d/spacetimeHosted by Matt O'DowdWritten by Katie McCormick and Matt O'Dowd Graphics by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal and Stephanie FariaGFX Visualizations: Katherine KorneiDirected by Andrew KornhaberAssistant Producer: Setare GholipourExecutive Producers: Eric Brown and Andrew KornhaberEnd Credits Music by J.R.S. Schattenberg: https://www.youtube.com/channel/UCRl6-nb4iOnsij-vnpAjp0QSpecial Thanks to Our Supporters on Patreon!Big Bang SupportersBrian ScottRick DeWittSandy WuMatthew MillerBrodie RaoScott GrayAhmad JodehRadu NegulescuAlexander TamasMorgan HoughJuan BenetVinnie FalcoFabrice EapMark RosenthalDavid NicklasQuasar SupportersHank SChristina OegrenMark HeisingHypernova SupportersWilliam BryanRich HammonsScott GorlickNick BerardPaul Stehr-GreenLeo EmersonmuOn MarketingRussell PopeBen DeloL. Wayne AusbrooksNicholas NewlinAdrian PosorMark Matthew BoskoАнтон КочковJohn R. SlavikMathewDanton SpiveyDonal BotkinJohn PollockEdmund FokschanerJoseph SalomoneMatthew O'Connorchuck zegarJordan Youngm0nkJohn HofmannTimothy McCullochGamma Ray Burst SupportersAlexey KamenskiyAndrew MacleodDiana SDouglas DraneBen CampbellLawrence Tholl, DVMFaraz KhanAlmog CohenAlex EdwardsNickÁdám KettingerSylvain LeducAnthony KahngMD3Endre PechDaniel JenningsCameron SampsonPratik MukherjeeGeoffrey ClarionNateDarren DuncanLily kawaiiRuss CreechJeremy ReedDerek DavisEric WebsterSteven SartoreDavid JohnstonJ. KingMichael BartonChristopher BarronJames RamseyDrew HartJustin JermynMr TAndrew MannJeremiah Johnsonfieldsa eleanoryPeter MertzKevin O'ConnellRichard DeightonIsaac SuttellDevon RosenthalOliver FlanaganDawn M FinkBleys GoodsonDarryl J LyleRobert WalterBruce BIsmael MontecelSimon OliphantMirik GogriMark Daniel CohenBrandon LattinNickolas Andrew FreemanShane CalimlimTybie FitzhughRobert IlardiAstaurusEric KieblerCraig StonahaMartin SkansMichael ConroyGraydon GossFrederic SimonTonyfaceJohn RobinsonA GKevin LeeAdrian HatchYurii KonovaliukJohn FunaiCass CostelloGeoffrey ShortBradley JenkinsKyle HoferTim StephaniLuaanAlecZeroVlad ShipulinCodyMalte UblKing Zeckendo