The Counterintuitive Physics of Turning a Bike minutephysics 2015-07-15 | Thanks to http://www.harrys.com for sponsoring this video – use offer code MinutePhysics for $5 off your first purchaseA HUGE thanks to Michael Aranda for aerial and slow motion photography and Wren Weichman (@wrenthereaper) for helping with the 3D bike animation.Bike references mainly from:http://bicycle.tudelft.nl/schwab/Bicycle/Music by Nathaniel Schroeder http://www.soundcloud.com/drschroederAnd thanks to the following Patreon supporters:Today I Found OutJeff StraathofAvi YashchinMark Jeremy CummingsWes BrownJohn GreenRafael Ferreira LucianoFlorian PhilippRens van der HeijdenRisa GalantRicky ShieldsKristina FossPetWolverine Trent SutherlandIan FooteEszter SzikoraTasso Kostalas (MavericSun)Amandeep HayerAbraão CaldasEric MaConner FissellBob BolchDaniel AmetsreiterJoël QuennevilleRichard PearsonDavid DaileySteven MulderKarim Ryan KyleWilliam RickettsCollin MandrisJonathan FosterSiddharth SadanandRobby OlivamAlan BrowningJonathan PiersaJake StolhandskeJulia PersonJames CraverSarah ChavisYonatan BiskRichard CampbellRichie SwiftChris BarrettJan AmzaChristopher ColemanDavid TebbeKelvin DueckDaniel “YoureDown” BregerHendrik PayerGreck CannonChris PetersLandy MandersonLewis GoddardSeamus CampbellGreg Holger R.Austin KellerAlejandro Medrano GilProf StickCora TonerChris ThompsonAlan LamAndrew CollingsMike McHargueNicholas BuckendorfBlair BradimoreMichael Biotnir lifshitzNicholas CarrollEdwin ZeaDiana DialMitch EtzkinLightbow Dante SantosMathias Westad LarssenTom HeadleyMichael KGeoff WallaceFredrik SamuelssonMelissa HarkinsJason TalleyKeith MarroccoMaarten BremerEric LabergeLacey LarsonNeil RamroopMatthew NortonEfe EfevichMark Donal BotkinSylvan RuudDaniel FriesenPhilipi Adolfo WillemannJeffrey McCulloughOddgeir Ann Brendon DavisFilip Christopher JimenezMichel PayetteJuha NiittynenJeff RossViktor LiljebladRobert E DeLappSean LinsleyChristopher O’NealMarcus Philip FreemanMatthew HeermannMarsha WoernerDaniel YipMatt KWilliam PearsonKevin LynchNick WardKevin john erikssonAllan FarrellTobias OlesenChris ChapinMichael KeefeJon MannBert Joji WataAdam NaberRob IbsenJacob GumpertPeter CollierAndi DavisRaymond CasonEvan GalePaul Tori McClanahanDominik Danilo MetzgerChristian AltenhofenRoy MorganOlivia DarrochAmber Ciarvellaryan horlacherKeith ChangJanel ChristensenWill SchererMike FulcherLarom LancasterJohn HarmanMatt Christos PapandreouFernando PazinJason MedranoAndrew BarnettKatharina SchuchmannJohn GietzenMichael TardibuonoMatthew HebertPierre-Louis BourgeoisGenevieve LawrenceBrian D’AgostiniChris Dominik MenziRyan A. SchauerDaniel JohnsonNico HoubrakenMichael CarrRagnhild Elizabeth MeisterlingLysann SchlegelMagnus KrokstadOwain BlackwoodRuss ArrellMaarten DaalderBrenden BullockMark SambergTina JohnstonMike CochraneTom MurphyPeter LJeff Erica PrattDavid Artur SzczyptaDavid DruedingNicklas UlvnäsNigel WJames NelsonMary Foster-SmithClayton NeffMichael MerinoJason and Gayle CorfmanMihaly BaraszSteven KlurfeldRichard BairwellTamas BartalErven Justin PrahlMichael MaitlenHans van StaverenKasey Karlin NazarioMarie ConradJacques LABBÉGeralyn Byersjason blackCandice BlodgettDaniel GibbsHenry BerthelsenAndy KittnerSteve HallRob SnyderJohn KellyJessica RosensteinBill TomiyasuVasco SimõesSimon Hammersleyiain Holger Alexis CarpenterJay GoodmanJoseph PerryMark GoveaEduardo Rampelotto Gatto Created by Henry Reich
The Moons Orbit is WEIRD minutephysics 2024-10-02 | Go to brilliant.org/MinutePhysics to try Brilliant for 30 days for FREE, and to get 20% off an annual premium subscription to Brilliant.We think of the moon as orbiting the earth, following a spiraling trajectory as the earth itself orbits the sun. But this is wrong. Not only is the moon's orbit NOT a spiral... there's an argument that the moon actually orbits the sun, not the earth! The moon's trajectory is more like a 12-sided polygon with curved corners than it is a spiral or even a wiggly line.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Does Pressure Keep the Deep Ocean From Freezing? minutephysics 2024-08-26 | Go to brilliant.org/minutephysics to try everything Brilliant has to offer for free for a full 30 days, and also get 20% off your annual premium subscription!Pressure *can* melt ice - like, you only need 500 times atmospheric pressure to melt ice down to negative four degrees celsius. If you have 1000 times atmospheric pressure (like at the bottom of the Mariana trench), then you'll melt ice down to around negative nine celsius. But that's for fresh water. For salty sea water, things are different.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsMinute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
The Color Temperature Paradox minutephysics 2024-07-24 | Go to brilliant.org/minutephysics to try everything Brilliant has to offer for free for a full 30 days, and also get 20% off your annual premium subscription!If you take a piece of white paper into different lighting conditions, it will be an objectively different color in each situation, but our brains are clever enough to make us feel like it's still white - it's still the same piece of paper, after all. To match our experience, cameras have to do this, too, "balancing" the colors of an image so that a white object looks white under a given light, rather than some other color. And the typical unit to measure the color of a light is the Kelvin. Which is weird, because Kelvin is a unit for measuring temperature, not color. What temperature and the color in a photograph have to do with each other comes down to history and physics.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Which Planet Has the Best Eclipse? minutephysics 2024-04-05 | Check out the interactive lab here: labs.minutelabs.io/eclipsesSolar eclipses don't just happen here on earth - moons of other planets also pass between those planets and the sun, resulting in various types of solar eclipses on Mars, Jupiter, Saturn, Uranus, Neptune, and even non-planets like Pluto, Eris and various asteroids. So, where are the best eclipses in the solar system? For that, we need a tier list.This Product is supported by the NASA Heliophysics Education Activation Team (NASA HEAT), part of NASA’s Science Activation portfolio. The material contained in this document is based upon work supported by a National Aeronautics And Space Administration (NASA) grant or cooperative agreement. Any questions, findings, conclusions or recommendations expressed in this materials are those of the author and do not necessarily reflect the views of NASA.Support MinutePhysics on Patreon! Link to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsMinute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Why Do Eclipses Travel WEST to EAST? minutephysics 2024-04-01 | The sun rises in the east, the moon rises in the east, and the stars rise in the east... but solar eclipses, oddly, come from the west. If total eclipses are caused by the sun and the moon, why don't they behave like the sun and the moon?This Product is supported by the NASA Heliophysics Education Activation Team (NASA HEAT), part of NASA’s Science Activation portfolio. The material contained in this document is based upon work supported by a National Aeronautics And Space Administration (NASA) grant or cooperative agreement. Any questions, findings, conclusions or recommendations expressed in this materials are those of the author and do not necessarily reflect the views of NASA.Support MinutePhysics on Patreon! Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why Arent There Eclipses Every Month? minutephysics 2024-03-21 | The moon orbits the earth once per month, which means the moon is on the sun side of the earth every month. So... "why aren't there eclipses every month?" is a question we will answer in this video!This Product is supported by the NASA Heliophysics Education Activation Team (NASA HEAT), part of NASA’s Science Activation portfolio. The material contained in this document is based upon work supported by a National Aeronautics And Space Administration (NASA) grant or cooperative agreement. Any questions, findings, conclusions or recommendations expressed in this materials are those of the author and do not necessarily reflect the views of NASA.Support MinutePhysics on Patreon! Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Should You Wipe Off Your Sweat? minutephysics 2023-12-20 | Want to donate to the highest-impact charities AND get your donation matched up to $100? Visit https://Givewell.org/MinutePhysicsIf you’re in scorching heat, or when your body is working hard and you’ve got hot, hot sweat all over, sticky and stifling - does wiping off the sweat help you cool off? Or is it better to leave it on?Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supporters**********************************REFERENCESHyperphysics:http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/sweat.htmlEngineering Toolbox Mollier Diagram:http://www.engineeringtoolbox.com/psychrometric-chart-mollier-d_27.htmlSweat Infohttp://www.anaesthesiamcq.com/FluidBook/fl3_3.phpOther articles:http://www.slate.com/articles/health_and_science/explainer/2012/06/should_you_wipe_away_your_sweat_or_does_that_keep_you_from_cooling_down_.htmlhttp://onlinelibrary.wiley.com/doi/10.1111/j.1748-1716.2012.02452.x/abstracthttp://lifehacker.com/5921036/dont-wipe-your-sweat-off-your-brow-itll-cool-you-down-fasterhttp://www.realclearscience.com/2012/06/28/does_wiping_sweat_prevent_you_from_cooling_off_247729.html**********************************CALCULATIONSTypical adult human body surface area ~ 1.5-2 m^2en.wikipedia.org/wiki/Body_surface_areaEvaporation rate at 25°C and 50% humidity, slight air movement (v~.5m/s) = .35kg/m^2/hrhttp://www.engineeringtoolbox.com/evaporation-water-surface-d_690.htmlSo in these conditions, a sweat-covered human can expect to evaporate ~.5-.75 L of water in an hour (For higher humidity (60-70%) it goes to ~.37-.5 L of water/hr). That amounts to ~0.25-0.35mm of sweat (covering the whole body) evaporated in an hour, or 6 micrometers every minute.Water has latent heat of 2,270 kJ/kg (http://www.engineeringtoolbox.com/water-thermal-properties-d_162.html), so in an hour a human can lose ~1100-1700 kJ of energy. (2270/4.1868 ~ 542 Cal)BUT that assumes all of the energy came from the person. If some proportion of it came from the air (~1/3-1/2?) then the person is only cooled down partially.Mass of a human ~ 60-80kg (en.wikipedia.org/wiki/Body_weight), assuming ~specific heat of water, ie 4 kJ/kg/K, could decrease temp by ~4.5-5°C.Energy used in moderate-hard exercise is ~20-30 kJ/kg/30 min, or ~40-60kJ/kg/h (http://www.weightloss.com.au/weight-loss/weight-loss-tools/exercise-energy-charts.html). Let’s say 50kJ/kg/h, which for average human amounts to 3000-4000 kJ/hr**********************************MinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsMinute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
The LAST Eclipse in History minutephysics 2023-12-13 | This Product is supported by the NASA Heliophysics Education Activation Team (NASA HEAT), part of NASA’s Science Activation portfolio. The material contained in this document is based upon work supported by a National Aeronautics And Space Administration (NASA) grant or cooperative agreement. Any questions, findings, conclusions or recommendations expressed in this materials are those of the author and do not necessarily reflect the views of NASA.We are in the Golden Age of Solar Eclipses, but only for the moment. In fact, I'd argue we're already past peak solar eclipse and it's all downhill from here.MinutePhysics is on twitter - @minutephysics And facebook - facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
But What IS A Lens Flare? minutephysics 2023-12-06 | Sign up for Brilliant (for free) and get 30 days of full access to all of their courses, go to brilliant.org/MinutePhysics - The first 200 people get 20% off a premium subscription! A lot of people took pictures of the recent solar eclipse in North America and got photos where there’s a ghostly image of the eclipse floating in the sky nowhere near where the sun is!REFERENCES:Lens flare prediction based on measurements with real-time visualization doi.org/10.1007/s00371-018-1552-4Physically-Based Real-Time Lens Flare Rendering http://doi.acm.org/10.1145/1964921.1965003From the Series of Articles on Lens Names: Tessar, by H. H. Nasse. Carl Zeiss Camera Lens Division March 2011cambridgeincolour.com/tutorials/lens-flare.htmtoolfarm.com/tutorial/in-depth-lens-flares-for-videopetapixel.com/what-is-lens-flaremaxon.net/en/red-giant/vfx-suite/real-lens-flares******************************Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
What if you pointed the Hubble telescope at Earth? @xkcd_whatif minutephysics 2023-11-29 | The first video we created together with our friends at xkcd is out now! You can find it here: http://youtube.com/@xkcd_whatif
The Bizarre Physics of Electric Guitars minutephysics 2023-06-14 | To try everything Brilliant has to offer—free—for a full 30 days, visit http://brilliant.org/MinutePhysicsThe first 200 people get 20% off a premium subscription! I was sent a magnetic guitar pick to review, so I reviewed it. Does it work? How? Why? What's the physics of electric guitar strings and pickups? Are magnets useful? Do they affect the strings? The pickups?Thanks to Pete B. for loaning me the guitar.Here are links to the youtube channel for the people who make the magnetic pick: youtube.com/@xpickAnd the videos critiquing itSamurai Guitarist: youtube.com/watch?v=zXTHRh1bQsgForlorn Hope: youtube.com/watch?v=2E8rrt5gE8QSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Geosynchronous Orbits are WEIRD minutephysics 2022-12-22 | Go to givewell.org/minutephysics to have your first donation matched up to $100!This video is about the physics of geosynchronous and geostationary orbits, why they exist, when they don't, when they're useful for communication/satellite TV, etc.REFERENCESFraction of a sphere that's visible from a given distancemath.stackexchange.com/questions/1329130/what-fraction-of-a-sphere-can-an-external-observer-seeOrbital perioden.wikipedia.org/wiki/Orbital_periodKepler's third lawen.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion#Third_lawKepler's 3rd law (which can be derived from Newton's law of gravitation and the centripetal force necessary for orbit as mr\omega^2=G\frac{mM}{r^2}, and using \omega=\frac{2\pi}{T}) is T = 2pi Sqrt(r^3/(GM)) where M is the mass of the central object, G is the gravitational constant. Alternatively, we can solve for r, r = (T^2/(4pi^2) GM)^(1/3) ~ T^(2/3)/M^(1/3) = (T^2/M)^(1/3).There is a limit (kind of like the Roche limit but for rotations). A rotating solid steel ball or other chunk of metal that has tensile strength (ie that isn't just a pile of stuff held together by gravity like most planets) would be able to spin faster.Calculate how much of a planet's surface you can see from a given geosynchronous orbit/radius? (Obviously for lower ones you can see less, etc) - d/(2(R+d)) where d is distance to surface, ie, R is sphere radius, R+d is object radius from sphere center.Let's plug that in with r being the geostationary orbit radius. That is, we have \frac{1}{2} \left(1- \left(\frac{4 \pi^2 R^3}{T^2 G M }\right)^{1/3}\right)Average density of a sphere \rho is given by \rho =M/(\frac{4}{3}\pi R^3), ie \rho=\frac{3M}{4 \pi R^3} aka\frac{M}{R^3}=\frac{4}{3}\pi \rho.So we can convert the "fraction of planet surface seen" to \frac{1}{2} \left(1- \left(\frac{3 \pi}{G \rho T^2}\right)^{1/3}\right)So as either \rho or T\to \infty, the fraction goes to a maximum of \frac{1}{2}. And the point of "singularity" where the orbit coincides with the surface is where G\rho T^2=3\pi, aka \rho=\frac{3\pi}{GT^2}. For a rotation period of 3600s, that corresponds to a density \rho \approx 11000kg/m^3, which is roughly twice the density of the earth. For a rotation period of 5400s, we have \rho\approx 4800kg/m^3, which is basically the density of the earth.Alternately, if we plug the density of the earth in to an orbit of period 5400s, we get as a fraction of the planet seen:\frac{1}{2} \left(1- \left(\frac{3 \pi}{G \rho T^2}\right)^{1/3}\right) = 0.02aka 2\% of the earth's surface.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why Penrose Tiles Never Repeat minutephysics 2022-12-01 | The first 200 people to brilliant.org/minutephysics get 20% off an annual premium subscription to Brilliant. Thanks to Brilliant for their support.This video is about a better way to understand Penrose tilings (the famous tilings invented by Roger Penrose that never repeat themselves but still have some kind of order/pattern). This project was a collaboration with Aatish Bhatia (https://aatishb.com).REFERENCESExplore Penrose and Penrose-like patterns: aatishb.com/patterncolliderVideo by Derek Muller/Veritasium about Penrose Patterns: youtube.com/watch?v=48sCx-wBs34Music algorithmically generated, algorithm designed by Henry ReichN.G. de Bruijn’s paper introducing the pentagrid/Penrose idea: https://www.math.brown.edu/reschwar/M272/pentagrid.pdfDe Bruijn, N.G., 1981. Algebraic theory of Penrose’s non-periodic tilings of the plane. Kon. Nederl. Akad. Wetensch. Proc. Ser. A, 43(84), pp.1-7.Here are some excellent in-depth references on how to construct Penrose Tiles Using the Pentagrid Method:Penrose Tilings Tied up in Ribbons by David Austin: http://www.ams.org/publicoutreach/feature-column/fcarc-ribbonsThe Empire Problem in Penrose Tilings by Laura Effinger-Dean: http://www.cs.williams.edu/~bailey/06le.pdfPentagrids and Penrose Tilings by Stacy Mowry & Shriya Shukla: https://web.williams.edu/Mathematics/sjmiller/public_html/hudson/HRUMC-Mowry&Shukla_Pentagrids%20and%20Penrose.pdfPenrose Tiling by Andrejs Treibergs: http://www.math.utah.edu/~treiberg/PenroseSlides.pdfAlgebraic Theory of Penrose's Non-Periodic Tilings of the Plane by N. G. de Bruijn: https://www.math.brown.edu/reschwar/M272/pentagrid.pdfParticularly good and helpful, and (we think) an undergrad thesis which is impressive!: http://www.cs.williams.edu/~bailey/06le.pdf An interesting popular science read on the discovery on quasicrystals and their connection to Penrose Tilings:The Second Kind of Impossible by Paul Steinhardt: bookshop.org/books/the-second-kind-of-impossible-the-extraordinary-quest-for-a-new-form-of-matter-9781476729930/9781476729930Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsMinute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Freezing water expands. What if you dont let it? minutephysics 2022-10-14 | The first 200 people to brilliant.org/minutephysics get 20% off an annual premium subscription to Brilliant. Thanks to Brilliant for their support.REFERENCESPage with TONS of info about water and icewater.lsbu.ac.uk/water/water_density.htmlSpecifically, a graph showing density & temperature & pressure along the phase line!!!!!water.lsbu.ac.uk/water/images/ice_water_density_1.gifWater freezing in isochoric conditions (theory):nature.com/articles/s42005-020-0303-9Water pressure/density calculatoromnicalculator.com/physics/water-densityhttp://www.csgnetwork.com/water_density_calculator.htmlArticle about pressure vs temperature vs volume expansion: Using freezing as a source of energylink.springer.com/article/10.1007/s42452-018-0139-z#:~:text=It%20is%20well%20known%20that,energy%20using%20a%20hydraulic%20motor.Latent heat of water at 0Clink.springer.com/referenceworkentry/10.1007/1-4020-3266-8_124#:~:text=A%20total%20of%20334%20J,the%20latent%20heat%20of%20fusion.Mariana Trenchen.wikipedia.org/wiki/Mariana_Trench#:~:text=At%20the%20bottom%20of%20the,atmospheric%20pressure%20at%20sea%20level.Regelation on wikipediaen.wikipedia.org/wiki/Regelation#:~:text=Regelation%20is%20the%20phenomenon%20of,heavy%20weight%20attached%20to%20it.Using Ice VI to freeze meat without tissue damagesciencedirect.com/science/article/abs/pii/S0309174003001931Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Youre Technically HOTTER Than The Sun (with XKCD!) minutephysics 2022-09-08 | Where to buy WHAT IF? 2 by Randall Munroe – Amazon: bit.ly/3Rk5Vy2 Barnes and Noble: bit.ly/3AKwXIl Penguin Random House: bit.ly/3HgfucP Books-A-Million: bit.ly/3Q4bEH3 Bookshop: bit.ly/3q26vVk IndieBound: bit.ly/3TyhX8W Apple Books: bit.ly/3wNNBp9FOR INTERNATIONAL EDITIONS, Including the UK and Germany, click here: xkcd.com/what-if-2The #1 New York Times bestselling author of What If? and How To answers more of the weirdest questions you never thought to ask The millions of people around the world who read and loved What If? still have questions, and those questions are getting stranger. Thank goodness xkcd creator Randall Munroe is here to help. Planning to ride a fire pole from the Moon back to Earth? The hardest part is sticking the landing. Hoping to cool the atmosphere by opening everyone’s freezer door at the same time? Maybe it’s time for a brief introduction to thermodynamics. Want to know what would happen if you rode a helicopter blade, built a billion-story building, made a lava lamp out of lava, or jumped on a geyser as it erupted? Okay, if you insist.Before you go on a cosmic road trip, feed the residents of New York City to a T. rex, or fill every church with bananas, be sure to consult this practical guide for impractical ideas. Unfazed by absurdity, Munroe consults the latest research on everything from swing-set physics to airliner catapult–design to answer his readers’ questions, clearly and concisely, with illuminating and occasionally terrifying illustrations. As he consistently demonstrates, you can learn a lot from examining how the world might work in very specific extreme circumstances.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters What if Pluto were plutonium? And Uranus uranium? And Mercury mercury? This video is based off of a chapter of the new xkcd book "What If? 2"MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Passing A Portal Through Itself minutephysics 2022-09-01 | Nebula Classes - Great classes by your favorite creators on a creator-owned streaming service: nebulaclasses.com/minutephysicsThis video is about what happens if you try to pass a portal (like in the video game Portal or Portal 2) through itself - do you get a paradox? Infinite recursion? Impossibility? Contradiction? The end of the world? Collapse of the wavefunction? Ultimately it ends up looking beautiful and weird and recursive and... just watch the video :)Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
How Many Fossils to Go an Inch? (ft. Robert Krulwich) minutephysics 2022-08-18 | A beautiful guest video by Robert Krulwich and Nate MiltonSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Another Portal Paradox minutephysics 2022-08-04 | We have a course on Brilliant! And the first 200 people to brilliant.org/minutephysics get 20% off an annual premium subscription to Brilliant, with full access to all courses, including ours. What happens if you extend a piston through a portal? Or try to sandwich a cube between two portals? That's right, it's time to explore more portal paradoxes!Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
The Trinity of Quality minutephysics 2022-06-29 | The first 200 people to brilliant.org/MinutePhysics get 20% off an annual Premium subscription to Brilliant. MinutePhysics is on Patreon: patreon.com/minutephysicsIn order to make something good, you need to have the right combination of three things: Quality, Discernment and Taste. This video is about quality vs quantity, the paradox of quality, how to make good content and good videos, etc. Based on my experience over the last decade running a collaborative creative business, MinuteEarth, where we do regular internal reflection and training on the craft of science communication.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Announcing... minutephysics 2022-06-16 | Check out MinuteFood! youtube.com/minutefood and support MinutePhysics: patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Most Collisions Are Secretly in One Dimension minutephysics 2022-05-26 | The first 200 people to brilliant.org/MinutePhysics get 20% off an annual Premium subscription to Brilliant.This video is about elastic and inelastic collisions in 1D, 2D and 3D - and how the collision of conservation of energy with conservation of momentum, plus a secret direction, results in a completely predetermined behavior for most collisions.REFERENCES1D Collision Calculator:http://hyperphysics.phy-astr.gsu.edu/hbase/col1d.html#c1Elastic collision of spheres Wolframdemonstrations.wolfram.com/ElasticCollisionsOfTwoSpheresOblique collisions of two 2D spheresiopscience.iop.org/article/10.1088/1361-6404/aab330Ballistic Pendulumhttp://hyperphysics.phy-astr.gsu.edu/hbase/balpen.htmlSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Is Anything on the Internet Real? minutephysics 2021-12-22 | GiveWell is matching donations from first-time donors dollar for dollar up to $250. Click on bit.ly/3DvVik8 to donate and be sure to use the fundraiser code MINUTEPHYSICS at checkout to make sure your donation gets matched.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
The Problem With The Butterfly Effect minutephysics 2021-10-21 | The first 200 people to go to brilliant.org/minutephysics get 20% off a Premium subscription to BrilliantSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
(A book with the answer) minutephysics 2021-10-08 | Get the new MinuteEarth book at: minuteearth.com/books !!Support MinutePhysics on Patreon: http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
The Rocket & String Paradox minutephysics 2021-08-18 | The first 200 people to go to http://brilliant.org/minutephysics get 20% off a premium subscription to Brilliant.This video is about Bell's Spaceship Paradox of Special Relativity, wherein a pair of rockets (or spacecraft) connected by a weak thread accelerate with uniform acceleration, maintaining the same separation, and the question is: does the thread break? And if so, why?REFERENCESInteractive Spacetime Globe by Alexander Wu:alexonscience.com/projects/spacetimeglobeRead an overview on Wikipedia:en.wikipedia.org/wiki/Bell%27s_spaceship_paradoxJohn Baez on Bell's Spaceship Paradox, Rindler Acceleration, etchttps://math.ucr.edu/home/baez/physics/Relativity/SR/BellSpaceships/spaceship_puzzle.htmlSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
A Better Way To Picture Atoms minutephysics 2021-05-19 | Thanks to Google for sponsoring a portion of this video!Support MinutePhysics on Patreon: http://www.patreon.com/minutephysics This video is about using Bohmian trajectories to visualize the wavefunctions of hydrogen orbitals, rendered in 3D using custom python code in Blender.REFERENCESA Suggested Interpretation of the Quantum Theory in Terms of "Hidden" Variables. IDavid Bohm, Physical Review, Vol 85 No. 2, January 15, 1952Speakable and Unspeakable in Quantum MechanicsJ. S. BellTrajectory construction of Dirac evolutionPeter HollandThe de Broglie-Bohm Causal Interpretation of Quantum Mechanics and its Application to some Simple Systems by Caroline ColijnBohmian Trajectories as the Foundation of Quantum Mechanicshttp://arxiv.org/abs/0912.2666v1The Pilot-Wave Perspective on Quantum Scattering and Tunnelinghttp://arxiv.org/abs/1210.7265v2A Quantum Potential Description of One-Dimensional Time-Dependent Scattering From Square Barriers and Square WellsDewdney, Foundations of Physics, VoL 12, No. 1, 1982 Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Windmills Are NOT Like Dams minutephysics 2021-04-01 | Watch the bonus material cut from this video at nebula.tv/minutephysicsThe Solution to the Windmill Paradox. This video is about the tradeoff of Windmills: the fact that the more kinetic energy you extract from the wind the slower the wind goes, the less wind you have to extract energy from, etc. How much energy is the sweet spot to extract from the wind??Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why Do Boats Make This Shape? minutephysics 2021-03-21 | Go to nebula.tv/minutephysics to get access to Nebula (where you can watch the extended version of this video), plus you'll get a 20% discount on an annual subscription.This video is about the "Kelvin wake" shape of water wakes behind boats - we talk about mach angle, dispersion, superposition of many waves, and how these all lead to the pattern of a wake. We don't get into Froude number though...REFERENCESBoat Wake Wikipedia Page: en.wikipedia.org/wiki/WakeInteractive Boat Wake Simulation: observablehq.com/@rreusser/dispersion-in-water-surface-wavesFeynman Lectures on Water Waves: https://www.feynmanlectures.caltech.edu/I_51.html#Ch51-S4Building up a Boat Wake from V-Shaped Wakes: editor.p5js.org/aatish/full/bDiykicsCWave Dispersion: en.wikipedia.org/wiki/Dispersion_relationMach angle shock waves:sciencedirect.com/topics/engineering/mach-angleShip Wakes - Kelvin or Mach Angle? Rabaud and Moisy Paper: journals.aps.org/prl/abstract/10.1103/PhysRevLett.110.214503Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
The Physics of Windmill Design minutephysics 2021-03-02 | This video was created in partnership with Bill Gates, inspired by his new book “How to Avoid a Climate Disaster.” Find out more here: gatesnot.es/3u7UUVUThis video is about how physics dictates the design of modern windmills - why they are so big, have so few blades, and have such skinny blades.REFERENCESH. Glauert: Aerodynamic Theory, 1935 Division L (Airplane Propellers), Chapter XI: Windmills and FansWind power extraction fundamentalshttps://home.uni-leipzig.de/energy/energy-fundamentals/15.htmBetz's Lawen.wikipedia.org/wiki/Betz%27s_lawTip Speed Ratioen.wikipedia.org/wiki/Tip-speed_ratioAerodynamics of Wind Turbines Bookamazon.com/Aerodynamics-Wind-Turbines-Physical-Analysis/dp/1119405610Penn State Wind Turbine Aerodynamics Lessonhttps://www.e-education.psu.edu/aersp583/node/469Wind Power Physics youtube videoyoutube.com/watch?v=qx_M0nvDIGUWhy do Wind Turbines Have Three Blades?rosemary-barnes.medium.com/why-do-wind-turbines-usually-have-3-blades-f7f95d714869Wind Power Fundamentalshttp://web.mit.edu/windenergy/windweek/Presentations/Wind%20Energy%20101.pdfWind Power Explainedcalcunation.com/blogs.php/the-physics-behind-wind-turbinesDrag Coefficienthttp://dx.doi.org/10.1615/AtoZ.d.drag_coefficientReynolds Number and Draghttp://www2.eng.cam.ac.uk/~mpj1001/learnfluidmechanics.org/LFM_blank_notes/handout_8_v3.pdfReynolds Numberen.wikipedia.org/wiki/Reynolds_numberViscosity of Airen.wikipedia.org/wiki/Viscosity#AirSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
General Relativity Explained in 7 Levels of Difficulty minutephysics 2021-02-18 | Go to nebula.tv/minutephysics to get access to Nebula (where you can watch the extended version of this video), plus you'll get a 20% discount on an annual subscription.This video covers the General theory of Relativity, developed by Albert Einstein, from basic simple levels (it's gravity, curved space) through to the concepts of how curved spacetime is represented by psuedo-Riemannian manifolds with Lorentzian signature (that is, special relativity and minkowski space are the local tangent space), how matter and energy are represented by an energy-momentum tensor, and how these two together obey the Einstein Field Equations. The solutions to the Einstein Field Equations (including the schwarzschild metric, kerr metric, freedman-lemaitre-robertson-walker metric, etc) represent gravity around massive objects like the sun, earth, and black holes, but also the history and expansion and future evolution of the cosmos. The universe on a large scale is described by general relativity - on a small scale, quantum mechanics. And where they meet... there's still work to be done.REFERENCESWald's textbook - General RelativityHartle's textbook - Gravity: An Introduction to Einstein's General RelativityCarlo Rovelli History of Quantum Gravity: https://cds.cern.ch/record/442809/files/0006061.pdfLeon Rosenfeld 1930 paper on quantum gravity: http://www.edoc.mpg.de/438547Kerr Metric Solution - en.wikipedia.org/wiki/Eddington%E2%80%93Finkelstein_coordinatesSchwarzschild Metric - en.wikipedia.org/wiki/Schwarzschild_metricEddington-Finkelstein Coordinates - en.wikipedia.org/wiki/Eddington%E2%80%93Finkelstein_coordinatesSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why LESS Sensitive Tests Might Be Better minutephysics 2021-01-14 | Thanks to Brilliant for sponsoring this video - the first 200 people to click on brilliant.org/MinutePhysics will get 20% off a Premium subscription to Brilliant.This video written & produced in collaboration with Aatish Bhatia, aatishb.comThis video is about how cheap, fast, and LESS sensitive rapid antigen tests might be better for screening (& maybe surveillance) than PCR COVID tests due to the nature of contagiousness/infectiveness at various points on the viral load trajectory of symptomatic and asymptomatic COVID sars-COV-2 carriers.REFERENCESThanks to Daniel Larremore for feedback on early versions of this video larremorelab.github.ioRapid Antigen Testing:COVID-19 testing: One size does not fit all. science.sciencemag.org/content/371/6525/126Rethinking Covid-19 Test Sensitivity — A Strategy for Containment. nejm.org/doi/full/10.1056/NEJMp2025631Test sensitivity is secondary to frequency and turnaround time for COVID-19 screening. advances.sciencemag.org/content/7/1/eabd5393.abstractThe effectiveness of population-wide, rapid antigen test based screening in reducing SARS-CoV-2 infection prevalence in Slovakia. (pre-print, not yet peer reviewed) medrxiv.org/content/10.1101/2020.12.02.20240648v1Effective Testing and Screening for Covid-19. rockefellerfoundation.org/wp-content/uploads/2020/09/A-National-Decision-Point-Effective-Testing-Screening-for-Covid-19-Full-Report.pdfBrown University & Harvard University modeling of COVID-19 testing shortfall. globalepidemics.org/testing-targetsFast Coronavirus Tests are coming. media.nature.com/original/magazine-assets/d41586-020-02661-2/d41586-020-02661-2.pdfOpen letter signed by epidemiologists and infectious disease experts supporting widespread & frequent rapid antigen testing for COVID-19: rapidtests.org/expert-letterMore information on various COVID-19 tests: https://chs.asu.edu/diagnostics-commons/testing-commonsField performance and public health response using the BinaxNOW Rapid SARS-CoV-2 antigen detection assay during community-based testing. academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1890/6052342Performance of an Antigen-Based Test for Asymptomatic and Symptomatic SARS-CoV-2 Testing at Two University Campuses. cdc.gov/mmwr/volumes/69/wr/mm695152a3.htmAsymptomatic Spread:People without symptoms spread virus in more than half of cases, CDC model finds washingtonpost.com/science/2021/01/07/covid-asymptomatic-spread(More than half of all) SARS-CoV-2 Transmission From People Without COVID-19 Symptoms. jamanetwork.com/journals/jamanetworkopen/fullarticle/2774707Three Quarters of People with SARS-CoV-2 Infection are Asymptomatic: Analysis of English Household Survey Data. ncbi.nlm.nih.gov/pmc/articles/PMC7549754Viral Load Curve:SARS-CoV-2 viral dynamics in acute infections. (pre-print, not yet peer reviewed)medrxiv.org/content/10.1101/2020.10.21.20217042v2Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why Masks Work BETTER Than Youd Think minutephysics 2020-09-08 | Thanks to the Heising-Simons foundation for their support: hsfoundation.org (their COVID-19 grants: hsfoundation.org/grants/covid-19-response-grants )Check out aatishb.com/maskmath to explore and for references.This video is about how masks (whether surgical, or N95, or cloth) are counterintuitive and actually work much better epidemiologically than one might expect. Masks do double-duty, and the fraction of interactions with masks is much higher than the fraction of people wearing masks, so partially adopted, partially effective masks are able to reduce the basic reproduction number surprisingly well.REFERENCES:Aatish’s detailed writeup on github: github.com/aatishb/maskmath/blob/master/model/mathmodel.ipynbAmid the Coronavirus Crisis, a Regimen for Re-entry: newyorker.com/science/medical-dispatch/amid-the-coronavirus-crisis-a-regimen-for-reentryFace Masks Against COVID-19: An Evidence Review preprints.org/manuscript/202004.0203/v3Mask FAQ Test Results: maskfaq.com/test-resultsThe Effect of Mask Use on the Spread of Influenza During a Pandemic: onlinelibrary.wiley.com/doi/full/10.1111/j.1539-6924.2010.01428.xCalibrated Intervention and Containment of the COVID-19 Pandemic: arxiv.org/ftp/arxiv/papers/2003/2003.07353.pdfCloth Mask Breathability and Filtration Efficiency Technical Report: static1.squarespace.com/static/5e8126f89327941b9453eeef/t/5f2c4463a5c9f75a38d2b26f/1596736614213/N95DECON_cloth_mask_breathability_filtrationtechnical_report_v1_200804.pdfWhat kind of mask should I be wearing to protect against COVID-19? http://built-envi.com/what-kind-of-mask-should-i-be-wearing-to-protect-against-covid-19Masks for all? The science says yes. fast.ai/2020/04/13/masks-summaryThe Real Reason to Wear a Mask: medium.com/the-atlantic/the-real-reason-to-wear-a-mask-e6405abbc484Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
The Astounding Physics of N95 Masks minutephysics 2020-06-18 | Head to brilliant.org/MinutePhysics to sign up for free and get 20% off a Premium subscription to Brilliant!This video was written in collaboration with Aatish Bhatia - aatishb.com To learn more about using & decontaminating N95 masks: n95decon.org Thanks to Manu Prakash for useful discussion and feedback (Manu is involved with the N95 decontamination project)Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters The physics & engineering of N95 mask design is pretty incredible.REFERENCES10X efficiency of electrically charged fibers"The electrostatic charge of N95 masks is a major contributor to their filtration efficiency, improving it at least 10-fold over uncharged fabric" (Tsai et al., Journal of Electrostatics 2002; Peter Tsai, personal communication).Prakash Lab COVID-19 Response Group Working Draft Document on N95 masks: docs.google.com/document/d/1aACcbkyZjR7nZy_wWeGQ9U2iGy0y4QajBeOL8RqAZIQ/edit“Electrostatic charge contributes as much as 95% of the filtration efficiency” Molina, A., Vyas, P., Khlystov, N., Kumar, S., Kothari, A., Deriso, D., ... & Prakash, M. (2020). Project 1000 x 1000: Centrifugal melt spinning for distributed manufacturing of N95 filtering facepiece respirators. arXiv preprint arXiv:2004.13494. arxiv.org/pdf/2004.13494.pdfTsai, P. P., Schreuder-Gibson, H., & Gibson, P. (2002). Different electrostatic methods for making electret filters. Journal of electrostatics, 54(3-4), 333-341. researchgate.net/profile/Phillip_Gibson/publication/222659741_Different_electrostatic_methods_for_making_electret_filters/links/5a5912cba6fdcc3bfb5ab21e/Different-electrostatic-methods-for-making-electret-filters.pdfHistory of Electrets Jefimenko, O. D., & Walker, D. K. (1980). Electrets. The Physics Teacher, 18(9), 651-659. aapt.scitation.org/doi/abs/10.1119/1.2340651Physics of Air Filtration Hinds, W. C. (1999). Aerosol technology: properties, behavior, and measurement of airborne particles. John Wiley & Sons. wiley.com/en-us/Aerosol+Technology%3A+Properties%2C+Behavior%2C+and+Measurement+of+Airborne+Particles%2C+2nd+Edition-p-9780471194101Scientific consortium for data-driven study of N95: n95decon.orgN95 & virus particle sizesBałazy, A., Toivola, M., Adhikari, A., Sivasubramani, S. K., Reponen, T., & Grinshpun, S. A. (2006). Do N95 respirators provide 95% protection level against airborne viruses, and how adequate are surgical masks?. American journal of infection control, 34(2), 51-57. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.488.4644&rep=rep1&type=pdfHarnish, D. A., Heimbuch, B. K., Husband, M., Lumley, A. E., Kinney, K., Shaffer, R. E., & Wander, J. D. (2013). Challenge of N95 filtering facepiece respirators with viable H1N1 influenza aerosols. Infection Control & Hospital Epidemiology, 34(5), 494-499. ncbi.nlm.nih.gov/pmc/articles/PMC4646082Liao, L., Xiao, W., Zhao, M., Yu, X., Wang, H., Wang, Q., ... & Cui, Y. (2020). "Can N95 respirators be reused after disinfection? How many times?. ACS nano. ncbi.nlm.nih.gov/pmc/articles/PMC7202248MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
How To Tell If Were Beating COVID-19 minutephysics 2020-03-27 | This video made possible with support of Brilliant - the first 200 subscribers to go to http://Brilliant.org/MinutePhysics get 20% off a Premium subscription to Brilliant. Go to http://aatishb.com/covidtrends to explore the graph from the video yourself!RESOURCESGrant's 3Blue1Brown Video: Exponential Growth and Epidemics: youtube.com/watch?v=Kas0tIxDvrgAatish's Exponential/Logistic Curve-Fitting Site: github.com/aatishb/covid/blob/master/curvefit.ipynbData Source: github.com/CSSEGISandData/COVID-19Our World in Data Page on Coronavirus: ourworldindata.org/coronavirusHow many tests for COVID-19 are being performed around the world? ourworldindata.org/covid-testingUnderstanding logarithmic scales: nytimes.com/2020/03/20/health/coronavirus-data-logarithm-chart.htmlWhat we can learn from the countries winning the coronavirus fight: https://www.abc.net.au/news/2020-03-26/coronavirus-covid19-global-spread-data-explained/12089028(Great explainer on log scales and growth curves explained in the context of COVID-19 in different countries)This video is a collaboration with Aatish Bhatia about how to see the COVID-19 tipping point - we present a better way to graph COVID-19 coronavirus cases using a logarithmic scale in "phase space" - plotting the growth rate against the cumulative cases, rather than either of these against time.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
How to Tell Matter From Antimatter | CP Violation & The Ozma Problem minutephysics 2020-02-26 | This video was made with the support of the Heising Simons Foundation.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters This video is about the Ozma problem of distinguishing the chirality (ie left-handedness or right-handedness) of matter using weak interaction processes like beta decay (for example in uranium), or neutral kaon/k-meson decay. This is wrapped up in the phenomenon of CP violation, by which charge and parity are both violated by certain weak interaction processes - this enables antimatter to be unambiguously distinguished from matter, and left handed chirality from right handed.REFERENCESThe Ozma Search for Extraterrestrial Intelligence (SETI) Projectseti.org/seti-institute/project/details/early-seti-project-ozma-arecibo-messageSean Carroll on CP Symmetry (& why we shouldn’t trot out baryogenesis all the time)preposterousuniverse.com/blog/2010/06/04/marketing-cp-violationElectroweak CP Violation on Scholarpediahttp://www.scholarpedia.org/article/CPviolationinelectroweakinteractionsThe Wu Experimenten.wikipedia.org/wiki/WuexperimentMartin Gardner, The New Ambidextrous Universebooks.google.com/books?id=kdLGa8cPPUC&lpg=PP1&pg=PR2#v=onepage&q&f=falseLecture notes on CP Violation and the CKM Matrix, Cambridge (Mark Thomson)hep.phy.cam.ac.uk/thomson/lectures/partIIIparticles/Handout122009.pdfHomochiralityen.wikipedia.org/wiki/HomochiralityL-glucose (vs D-glucose)en.wikipedia.org/wiki/L-GlucoseRadioactive Nucleus Decayhttp://www.radioactivity.eu.com/site/pages/RadioactiveSeries.htmCP Violation in Semi-Leptonic Decays (SEE PAGE 426 for reference to definition of MATTER)hep.phy.cam.ac.uk/thomson/lectures/partIIIparticles/Handout122009.pdfKaon Decay Modeshttp://pdg.lbl.gov/2012/listings/rpp2012-list-K-zero-L.pdfFlipped bowling Jesus scene in Big Lebowskiyoutube.com/watch?v=lWz8NGIisMoIsotopes of Uraniumen.wikipedia.org/wiki/IsotopesofuraniumBeta Decayen.wikipedia.org/wiki/BetadecayThe Wu Experimenten.wikipedia.org/wiki/WuexperimentKaonsen.wikipedia.org/wiki/KaonCP Violation in Symmetry Magazinesymmetrymagazine.org/article/charge-parity-violationPhysics Stack Exchange on CP Violationphysics.stackexchange.com/questions/160511/what-cp-violating-processes-do-we-know-ofMinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Reimagining the Periodic Table minutephysics 2019-12-20 | Go to https://Brilliant.org/MinutePhysics to gift Brilliant Premium for the holidays, and for 20% off!This video is about cutting, taping, and rearranging the periodic table into the Left Step form, the Mendeleev's flower form, the cake form, the wide form, the standard form, and so on. A great holiday craft!!REFERENCESAlternate Periodic Tablesen.wikipedia.org/wiki/Alternative_periodic_tablesElectronegativityen.wikipedia.org/wiki/ElectronegativityAtomic Radius Radiien.wikipedia.org/wiki/Atomic_radiusFirst Ionization energyen.wikipedia.org/wiki/Ionization_energySupport MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
Why Do Mirrors Flip Left & Right (but not up & down)? minutephysics 2019-12-06 | Go to nebula.tv/minutephysics to get access to Nebula (where you can watch MinuteBody) plus you'll get a 20% discount on an annual subscription. Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersThis video is about why words flip left & right (aka horizontally) in a mirror but not up & down (aka vertically). The answer has to do with specular reflection, mirrors being like windows into another world (alternate universes, just with in and out flipped!), and transparency of the things we write on.REFERENCESSpecular Reflectionen.wikipedia.org/wiki/Specular_reflectionPhysicsGirl video about mirrorsyoutube.com/watch?v=vBpxhfBlVLUFermat’s principlehttp://electron6.phys.utk.edu/optics421/modules/m1/Fermat's%20principle.htmThomas-Fermi screeningen.wikipedia.org/wiki/Thomas%E2%80%93Fermi_screeningMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Do Photons Cast Shadows? minutephysics 2019-11-06 | Thanks to Nebula for their support. Go to nebula.tv/minutephysics to get Nebula! Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersThis video is about two-photon (gamma-gamma) physics, and how photons can interact with each other - either mediated by a passing lepton, or gravitationally via lensing, or via vacuum fluctuation pair production of vertical particles (electron-positron pair, for example). This is the so-called "box diagram" feynman diagram.REFERENCESWater waves interact with each other (weakly nonlinear shallow water waves)en.wikipedia.org/wiki/Korteweg%E2%80%93deVriesequationhttp://mathworld.wolfram.com/Korteweg-deVriesEquation.htmlPaper: Absorption of Very High Energy Gamma Rays in the Milky Wayarxiv.org/pdf/1608.01587.pdfPaper: Observing light-by-light scattering at the Large Hadron Collider (LHC)arxiv.org/pdf/1305.7142.pdfMass-Energy Scalehttp://labs.minutelabs.io/Mass-Energy-ScaleOptical Depthen.wikipedia.org/wiki/OpticaldepthThe electromagnetic spectrum and photon energieshttp://labman.phys.utk.edu/phys222core/modules/m6/The%20EM%20spectrum.htmlGravitational Lensinghttp://andybohn.com/research/lensing.htmlAsk an Astrophysicist on gamma ray scattering and energies in cosmologyhttp://teacherlink.ed.usu.edu/tlnasa/reference/imaginedvd/files/imagine/docs/askastro/answers/970412e.htmlMeasuring Vacuum Polarisation with High Power Lasersarxiv.org/pdf/1510.08456.pdfDetecting vacuum birefringence with X-ray free electron lasers and high-power optical lasershttps://indico.desy.de/indico/event/12654/session/2/contribution/8/material/slides/0.pdfVacuum birefringence in the head-on collision of XFEL and optical high-intensity laser pulsesarxiv.org/pdf/1807.03302.pdfATLAS makes first direct detection of Light-by-light scattering at the LHChttps://atlas.cern/updates/press-statement/atlas-sees-first-direct-evidence-light-light-scattering-high-energyTwo Photon Physicshttp://www.hep.ucl.ac.uk/opal/gammagamma/gg-tutorial.htmlen.wikipedia.org/wiki/Two-photonphysicsThesis: The Opacity of the Universe for high and very high energy γ-rayshttp://inspirehep.net/record/1254304/files/desy-thesis-13-033.pdfMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
The Man Who Corrected Einstein minutephysics 2019-10-15 | Sign up for Brilliant FOR FREE at http://brilliant.org/minutephysics - the first 200 people get 20% of a premium subscription.This video is about how Russian physicist Aleksandr Fridman corrected Albert Einstein about the expansion of the universe. Einstein thought that general relativity implied that space had to be static and unchanging, but he had made a technical error regarding the differentiation of the metric (in particular, I believe he mistook the determinant of the metric for a scalar rather than a tensor density of weight 2). Friedmann didn't make this differential geometric mistake, and the cosmologies he found from the Einstein Equations were more varied in their properties - they could be expanding, or contracting, or (with the cosmological constant), static.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersREFERENCESAlexander Friedmannen.wikipedia.org/wiki/Alexander_FriedmannEinstein Wrongly Criticizes Alexander Friedmannhttps://einsteinpapers.press.princeton.edu/vol13-trans/301Alexander Friedmann Corrects Einsteinhttps://einsteinpapers.press.princeton.edu/vol13-trans/363Einstein Admits his Mathematical Mistakehttps://einsteinpapers.press.princeton.edu/vol14-trans/77Interrogating the Legend of Einstein’s “Biggest Blunder”arxiv.org/abs/1804.06768Cosmological Considerations in the General Theory of Relativityhttps://einsteinpapers.press.princeton.edu/vol6-trans/433On the General Theory of Relativity (Einstein)https://einsteinpapers.press.princeton.edu/vol6-trans/110The Field Equations of Gravitationhttps://einsteinpapers.press.princeton.edu/vol6-trans/129The Einstein Field Equationsen.wikipedia.org/wiki/Einstein_field_equationsPresentation about the Sequence of Eventshttp://web.mit.edu/8.286/www/slides07/Einstein-and-Friedmann.pdfTensor Densities:en.wikipedia.org/wiki/Tensor_densityMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
When Its OK to Violate Privacy minutephysics 2019-09-21 | Go to http://www.dashlane.com/minutephysics for a free 30 day trial and 10% discount with offer code 'minutephysics' Watch the main video here: youtube.com/watch?v=pT19VwBAqKASupport MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersREFERENCESCynthia Dwork (key inventor of Differential Privacy), giving a great intro talk about differential privacyyoutube.com/watch?v=lg-VhHlztqoHazards of Smoking: the Effect on Life Spannejm.org/doi/pdf/10.1056/NEJMsa1211128NHL Hockey Birth distributionsquanthockey.com/nhl/birth-month-totals/nhl-players-career-stats.htmlMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Protecting Privacy with MATH (Collab with the Census) minutephysics 2019-09-12 | This video was made in collaboration with the US Census Bureau and fact-checked by Census Bureau scientists. Any opinions and errors are my own. For more information, visit census.gov/about/policies/privacy/statistical_safeguards.html or search "differential privacy" at http://census.gov.REFERENCESDifferential Privacy in the Wild: http://www.vldb.org/pvldb/vol9/p1611-machanavajjhala.pdfHarvard University Privacy Tools Project: https://privacytools.seas.harvard.edu/differential-privacySimons Institute Workshop Video Recordings and Articles Archive: https://simons.berkeley.edu/workshops/schedule/6281Cynthia Dwork (key inventor of Differential Privacy), giving a great intro talk about differential privacy: youtube.com/watch?v=lg-VhHlztqoShiva P Kasiviswanathan and Adam Smith. On the semantics of differential privacy: A Bayesian formulation. Journal of Privacy and Confidentiality, 6(1):1–16, 2014.Shiva Prasad Kasiviswanathan and Adam Smith. On the ‘semantics’ of differential privacy: A Bayesian formulation. 2015. https://arxiv.org/abs/0803.3946Daniel Kifer and Ashwin Machanavajjhala. A rigorous and customizable framework for privacy. In ACM Symposium on Principles of Database Systems (PODS), 2012.Daniel Kifer and Ashwin Machanavajjhala. Pufferfish: A framework for mathematical privacy definitions. ACM Trans. Database Syst., 39(1):3, 2014.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
How to Build a Lava Moat (with xkcd) minutephysics 2019-08-30 | Where to Buy "How To" by Randall Munroe:· PRH.com: bit.ly/2L2G5hy· Amazon: bit.ly/2zfy974· Barnes and Noble: bit.ly/2Zozxmt· IndieBound: bit.ly/2ZfwSre· Books-A-Million: bit.ly/2ZfxD3y· Apple Books: bit.ly/33TK3kXThe world's most entertaining and useless self-help guide, from the brilliant mind behind the wildly popular webcomic xkcd and the #1 New York Times bestsellers What If? and Thing ExplainerFor any task you might want to do, there's a right way, a wrong way, and a way so monumentally complex, excessive, and inadvisable that no one would ever try it. How To is a guide to the third kind of approach. It's full of highly impractical advice for everything from landing a plane to digging a hole. Bestselling author and cartoonist Randall Munroe explains how to predict the weather by analyzing the pixels of your Facebook photos. He teaches you how to tell if you're a baby boomer or a 90's kid by measuring the radioactivity of your teeth. He offers tips for taking a selfie with a telescope, crossing a river by boiling it, and powering your house by destroying the fabric of space-time. And if you want to get rid of the book once you're done with it, he walks you through your options for proper disposal, including dissolving it in the ocean, converting it to a vapor, using tectonic plates to subduct it into the Earth's mantle, or launching it into the Sun.By exploring the most complicated ways to do simple tasks, Munroe doesn't just make things difficult for himself and his readers. As he did so brilliantly in What If?, Munroe invites us to explore the most absurd reaches of the possible. Full of clever infographics and amusing illustrations, How To is a delightfully mind-bending way to better understand the science and technology underlying the things we do every day.REFERENCESHow To (Randall Munroe) - see above for links!Rock melting pointshttp://hyperphysics.phy-astr.gsu.edu/hbase/Geophys/meltrock.htmlSyracuse University Researchers Make Lava Using Keweenawan Basalthttp://lavaproject.syr.edu/making-lava/making.htmlBEDROCK GEOLOGY OF WISCONSIN MAP: UNIVERSITY OF WISCONSIN–EXTENSION Geological and Natural History SurveyElectric Furnaceamazon.com/Automatic-Electric-Refining-Precious-Aluminum/dp/B07LCKKFWXLarge Geothermal Power Plantsworldatlas.com/articles/largest-geothermal-power-plants-in-the-world.htmlcalpine.com/operations/power-operations/our-locations/california/ridge-lineCoal Power Plant Capacitytalenenergy.com/plant/colstripThe size of an A19 or A21 Lightbulbblog.1000bulbs.com/home/a21-vs-a19Low melting point Vanadate glassiopscience.iop.org/article/10.1143/JJAP.50.088002Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Why Some Days Aren’t 24 Hours minutephysics 2019-08-23 | Check out the "What is a Day?" interactive video at labs.minutelabs.io/what-is-a-dayIt's super cool!! (and made by Jasper Palfree & the MinuteEarth/MinutePhysics team)The MinutePhysics video about Why December Has the Longest Days: youtube.com/watch?v=nZMMuv0LtyoThis video is about the length of a solar day vs a stellar day vs a mean standard day, what they all have to do with each other and the earth's orbit, eccentricity, axial tilt, and so on. Also, aliens and asteroids. It'll explain the equation of time, and why the longest day is in December. The lab will also show you what days are like on all the other planets - Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and even - though it's not a planet - Pluto.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Einsteins Biggest Blunder, Explained minutephysics 2019-08-01 | Thanks to Brilliant for supporting MinutePhysics. Get 20% off a premium subscription at brilliant.org/MinutePhysicsThis video is about how Albert Einstein made a mistake when applying the Field Equations of General Relativity to cosmology (in particular, to a static, constant density universe), and solved the problem by introducing the cosmological constant, rather than allowing for a dynamic universe with a scale factor - that is, the Friedmann-Lemaitre-Robertson-Walker universe, first developed by Alexander Friedmann of Russia. Later, it was discovered by the Slipher and Hubble red-shift that the universe is indeed expanding, and even later, by Schwarz and company in 1998, that the expansion is accelerating - aka, dark energy. And the cosmological constant was re-introduced.Thanks to Grant Sanderson of http://www.youtube.com/3Blue1Brown for help with the fancy equation animation!REFERENCESThe Einstein Field Equationsen.wikipedia.org/wiki/Einstein_field_equationsInterrogating the Legend of Einstein’s “Biggest Blunder”arxiv.org/abs/1804.06768On the General Theory of Relativity (Einstein)https://einsteinpapers.press.princeton.edu/vol6-trans/110The Foundation of the General Theory of Relativity (Albert Einstein)https://einsteinpapers.press.princeton.edu/vol6-trans/158Cosmological Considerations in the General Theory of Relativityhttps://einsteinpapers.press.princeton.edu/vol6-trans/433Einstein Wrongly Criticizes Alexander Friedmannhttps://einsteinpapers.press.princeton.edu/vol13-trans/301Alexander Friedmann Corrects Einsteinhttps://einsteinpapers.press.princeton.edu/vol13-trans/363Einstein Admits his Mathematical Mistakehttps://einsteinpapers.press.princeton.edu/vol14-trans/77The Field Equations of Gravitationhttps://einsteinpapers.press.princeton.edu/vol6-trans/129George Gamowen.wikipedia.org/wiki/George_GamowMach’s Principleen.wikipedia.org/wiki/Mach%27s_principleEquivalence Principleen.wikipedia.org/wiki/Equivalence_principleSean Carroll and William Press Paperpreposterousuniverse.com/wp-content/uploads/cpt92.pdfSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
The Portal Paradox minutephysics 2019-06-28 | Go to nebula.tv/minutephysics to get access to Nebula, plus you'll get a 20% discount on an annual subscription.This video is about the Portal Paradox - a paradox in the video game Portal (and Portal 2) regarding whether or not a companion cube passing through a moving portal plops out of the other end with no speed (velocity, momentum), or shoots out at high speed. It’s a question of conservation of momentum, relativity of velocities, wormholes, 3D printers and quantum teleportation, glitches, and more.REFERENCESConservation of momentumen.wikipedia.org/wiki/Momentum#Conservation_in_a_continuumPrinciple of Localityen.wikipedia.org/wiki/Principle_of_localityYouTube video of testing the Portal 2 game engine on the portal Paradox youtu.be/S85nudR6D-YTutorial for how to program the Portal portals on your own: gamasutra.com/view/feature/132164/games_demystified_portal.phpSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Our Ignorance About Gravity minutephysics 2019-06-20 | Thanks to the Heising Simons Foundation (hsfoundation.org) for their support of this video, and of short range gravity research.This video is about how little we know about the behavior of gravity at short length and distance scales, what the constraints are on the inverse square law/Newton's law of universal gravitation, at the human and microscopic and atomic scales. Only on solar system scales or larger do we have good constraints on Newton's law of gravitation.REFERENCESReview of short-range gravity experiments in the LHC eraarxiv.org/abs/1408.3588v2Zeptonewton force sensing with nanospheres in an optical latticearxiv.org/abs/1603.02122Large extra dimensionsen.wikipedia.org/wiki/Large_extra_dimensionSearch for Screened Interactions Associated with Dark Energy Below the 100 μm Length Scalearxiv.org/abs/1604.04908Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scalearxiv.org/abs/hep-ph/0611184v1Photon Mass Experimenthttp://dx.doi.org/10.1119/1.13149Torsion balance experiments: A low-energy frontier of particle physicsE.G. Adelberger, J.H. Gundlach, B.R. Heckel, S. Hoedl, S. Schlammingerdoi:10.1016/j.ppnp.2008.08.002TESTS OF THE GRAVITATIONAL INVERSE-SQUARE LAWE.G. Adelberger, B.R. Heckel, and A.E. NelsonAnnu. Rev. Nucl. Part. Sci. 2003. 53:77–121 doi: 10.1146/annurev.nucl.53.041002.110503Physical Review A, Vol 33, No 1: Improved result for the accuracy of Coulomb's law: A review of the Williams, Faller, and Hill experiment. Lewis P. Fulcher.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
I Had to Build a Custom Mute Switch for my Violin minutephysics 2019-06-04 | Thanks to Brilliant for supporting this video! The first 200 people to go to brilliant.org/MinutePhysics will get 20% off a premium subscription to Brilliant.Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsThis video is about how I designed and made my own custom mute guitar pedal for my clip-on mic and piezo pickup on my violin (fiddle). The mic is an AT Pro35 phantom powered XLR condensor microphone, and the pickup is a Fishman V200 piezoelectric transducer. I got all of the parts from PartsExpress.Thanks to my band (youtube.com/channel/UCEKRoVVSZKGih6v_xK4LAdw), Caleb, Pete, Paul and Troy, and to Hannah for filming. Link to Patreon Supporters: http://www.minutephysics.com/supportersREFERENCES:Gearslutz mute wiring for phantom powered vs dynamic/line-level microphones:gearslutz.com/board/geekslutz-forum/813680-how-wire-external-xlr-off-switch-pedal.htmlBeavis Audio Research:http://beavisaudio.com/techpagesPickups on wikipedia: en.wikipedia.org/wiki/Pickup_%28music_technology%29Microphone mute pedal on “I like to make stuff”iliketomakestuff.com/make-microphone-mute-pedalBalanced vs unbalanced audio:http://www.aviom.com/blog/balanced-vs-unbalancedBalanced signals on wikipedia:en.wikipedia.org/wiki/Balanced_audioPhantom Power:http://acousticguitar.com/everything-you-need-to-know-about-microphone-phantom-powerPhantom Power explained on Sweetwater:sweetwater.com/insync/how-phantom-power-worksPiezoelectricity:en.wikipedia.org/wiki/Piezoelectricity#MechanismMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
How Shors Algorithm Factors 314191 minutephysics 2019-05-22 | Go to http://www.dashlane.com/minutephysics to download Dashlane for free, and use offer code minutephysics for 10% off Dashlane Premium!Watch the main video: youtube.com/watch?v=lvTqbM5Dq4QSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysicsThis video explains how Shor’s Algorithm factors the pseudoprime number 314191 into its prime factors using a quantum computer. The quantum computation relies on the number-theoretic analysis of the factoring problem via modular arithmetic mod N (where N is the number to be factored), and finding the order or period of a random coprime number mod N. The exponential speedup comes in part from the use of the quantum fast fourier transform which achieves interference among frequencies that are not related to the period (period-finding is the goal of the QFT FFT).REFERENCESRSA Numbers (sample large numbers to try factoring)en.wikipedia.org/wiki/RSA_numbersIBM on RSA ibm.com/support/knowledgecenter/en/SSB23S1.1.0.13/gtps7/s7pkey.htmlModulo Multiplication Group Tables http://mathworld.wolfram.com/ModuloMultiplicationGroup.htmlDifference of squares factorization en.wikipedia.org/wiki/Difference_of_two_squares Euclid’s Algorithm en.wikipedia.org/wiki/Euclideanalgorithm Rational sieve for factoring en.wikipedia.org/wiki/Rational_sieve General Number field Sieve en.wikipedia.org/wiki/Generalnumberfieldsieve Scott Aaronson blog post about Shor’s Algorithm scottaaronson.com/blog/?p=208 Experimental implementation of Shor’s Algorithm (factoring 15, 21, and 35) arxiv.org/pdf/1903.00768.pdf Adiabatic Quantum Computation factoring the number 291311 arxiv.org/pdf/1706.08061.pdf Scott Aaronson course notes scottaaronson.com/qclec scottaaronson.com/qclec/combined.pdf Shor’s Algorithm on Quantiki quantiki.org/wiki/shors-factoring-algorithm TLS And SSL use RSA encryption en.wikipedia.org/wiki/TransportLayerSecurity Dashlane security whitepaper dashlane.com/download/DashlaneSecurityWhitePaperOctober2018.pdf Link to Patreon Supporters: http://www.minutephysics.com/supporters MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
How Quantum Computers Break Encryption | Shors Algorithm Explained minutephysics 2019-05-01 | Go to http://www.dashlane.com/minutephysics to download Dashlane for free, and use offer code minutephysics for 10% off Dashlane Premium!Support MinutePhysics on Patreon! http://www.patreon.com/minutephysicsThis video explains Shor’s Algorithm, a way to efficiently factor large pseudoprime integers into their prime factors using a quantum computer. The quantum computation relies on the number-theoretic analysis of the factoring problem via modular arithmetic mod N (where N is the number to be factored), and finding the order or period of a random coprime number mod N. The exponential speedup comes in part from the use of the quantum fast fourier transform which achieves interference among frequencies that are not related to the period (period-finding is the goal of the QFT FFT).REFERENCESRSA Numbers (sample large numbers to try factoring)en.wikipedia.org/wiki/RSA_numbersIBM on RSAibm.com/support/knowledgecenter/en/SSB23S1.1.0.13/gtps7/s7pkey.htmlModulo Multiplication Group Tableshttp://mathworld.wolfram.com/ModuloMultiplicationGroup.htmlDifference of squares factorizationen.wikipedia.org/wiki/Difference_of_two_squaresEuclid’s Algorithmen.wikipedia.org/wiki/EuclideanalgorithmRational sieve for factoringen.wikipedia.org/wiki/Rational_sieveGeneral Number field Sieveen.wikipedia.org/wiki/GeneralnumberfieldsieveScott Aaronson blog post about Shor’s Algorithmscottaaronson.com/blog/?p=208Experimental implementation of Shor’s Algorithm (factoring 15, 21, and 35)arxiv.org/pdf/1903.00768.pdfAdiabatic Quantum Computation factoring the number 291311arxiv.org/pdf/1706.08061.pdfScott Aaronson course notesscottaaronson.com/qclecscottaaronson.com/qclec/combined.pdfShor’s Algorithm on Quantikiquantiki.org/wiki/shors-factoring-algorithmTLS And SSL use RSA encryptionen.wikipedia.org/wiki/TransportLayerSecurityDashlane security whitepaperdashlane.com/download/DashlaneSecurityWhitePaperOctober2018.pdfLink to Patreon Supporters: http://www.minutephysics.com/supportersMinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
Why Do Compressed Air Cans Get Cold? minutephysics 2019-04-03 | Thanks to http://brilliant.org/minutephysics for supporting MinutePhysics - get 20% a premium subscription at http://brilliant.org/minutephysicsSupport MinutePhysics on Patreon! http://www.patreon.com/minutephysicsLink to Patreon Supporters: http://www.minutephysics.com/supportersThis video is about compressed air cans (aka gas dusters) and why they get cold when you spray them. They cool off because the refrigerant inside (1,1-difluoroethane) is under pressure and boils off when the pressure lowers, and energy lost to the latent heat of vaporization cools the can a lot. Difluoroethane normally boils at -25°C (-13°F), but under ~6 atm (6 bar, 600 kpa) it is a liquid at room temperature. The gas also cools off slightly due to the Joule-Thompson effect of fluid expansion through a throttled valve. Difluoroethane is heavier than air and water soluble, so it is recommended to use it in a ventilated environment to clean your keyboard, etc. Also, 1,1-difluoroethane is a potent greenhouse gas. It is also known as Freon 152a, Ethylidene difluoride, Ethylidene fluoride, HFC-152a, R-152a, and DFE.Thanks to Tino and Hannah!REFERENCESCRC Air Duster Safety Data Sheethttp://docs.crcindustries.com/msds/5185.pdfLatent Heat of vaporizationen.wikipedia.org/wiki/Latentheat1,1-difluoroethane chemical and physical propertieswebbook.nist.gov/cgi/cbook.cgi?ID=C75376&Mask=3FFF1,1-difluoroethane on wikipediaen.wikipedia.org/wiki/1,1-DifluoroethaneFree Expansion of Real Gases, Goussard, 1993http://dx.doi.org/10.1119/1.17417Joule-Thompson Expansion Course Noteshttp://tccc.iesl.forth.gr/education/local/Labs-PC-II/JT.pdfProperties of 1,1-difluoroethanehttp://www.inchem.org/documents/sids/sids/75376.pdfpubchem.ncbi.nlm.nih.gov/compound/11-difluoroethaneMedical Effects of difluoroethanetoxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+5205MinutePhysics is on twitter - @minutephysicsAnd facebook - http://facebook.com/minutephysicsAnd Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!Created by Henry Reich
