Podcasts about mpemba

Roberto Pascua hoy nos despeja la duda sobre si podemos meter comida caliente en la nevera y por qué. El efecto Mpemba, ¡no te lo pierdas!

La Patética en el Teatro Valle-Inclán, ruta por la Nacional VI, conocemos el efecto Mpemba y los hábitos para cultivar la alegría en familia.

INSCREVA-SE NO CANAL, AJUDA MUITO

Researchers from Trinity College Dublin have just described the existence of the paradoxical Mpemba effect within quantum systems. Initially investigating out of pure curiosity, the discovery has bridged the gap between Aristotle's observations two millennia ago and modern-day understanding, and opened the door to a whole host of "cool" - and "cooling" - implications. The Mpemba effect is best known as a perplexing phenomenon, where hot water freezes faster than cold water. Observations of the counter-intuitive effect date back to Aristotle who, over 2,000 years ago, noted that the Greeks of Pontus were exploiting the effect in their fishing practices. The Mpemba effect has also stoked the curiosity of other great minds throughout history, such as René Descartes and Francis Bacon. It continues to be the subject of numerous broadsheet articles and pops up regularly as a curious focus in various settings, such as in cooking competition MasterChef, where contestants have tried capitalising on the effect to deliver frozen delicacies more quickly than seems possible in dessert challenges. And now, we can say that this strange effect is much more ubiquitous than we previously expected as the Trinity QuSys team, led by Prof. John Goold from the School of Physics, has just published a fascinating research paper in the journal Physical Review Letters. The paper outlines their breakthrough in understanding the effect in the very different - and extremely complex - world of quantum physics. Prof. Goold said: "The 'Mpemba effect' gets its name from Erasto Mpemba who, as a school kid in 1963, was making ice cream in his home economics class in Tanzania. Mpemba did not wait for his hot ice cream mixture to cool before putting it directly in the fridge and was unsurprisingly puzzled to find that it froze before all the colder samples of his classmates. "He pointed this out to his teacher, who ridiculed him for not knowing his physics - Newton's law of cooling, for example, tells us that the rate at which an object cools is proportional to the temperature difference between the object and its surroundings. However, Mpemba convinced a visiting professor - Denis Osoborne from the University of Dar es Salaam - to test what he had seen and the pair published a paper that indeed evidenced the strange effect." While the Mpemba effect is still not wholly understood - its presence is hotly debated at the macroscopic scale - it is much more apparent on the microscopic scale, where physicists use the theory of quantum mechanics to describe nature. The quantum Mpemba effect has recently become a trending topic, but myriad questions hung in the air; for example, how does the quantum effect relate to the original effect? And can we construct a thermodynamic framework to understand the phenomenon better? The QuSys research group's breakthrough answers some of the key questions. Prof. Goold said: "We are experts in the interface between non-equilibrium thermodynamics and quantum theory and, as such, we have the right toolbox to tackle these questions. Our work essentially provides a recipe to generate the Mpemba effect in quantum systems, where a physical transformation that effectively 'heats' the quantum system can be performed. This transformation of the quantum system then paradoxically allows it to relax or 'cool' exponentially faster by exploiting unique features in quantum dynamics." Using the toolkit of non-equilibrium quantum thermodynamics, the team has successfully bridged the gap between Aristotle's observations from two millennia ago and our modern understanding of quantum mechanics. And it now opens the door to many research and applications-related questions. Prof. Goold added: "While we first took this project on out of intellectual curiosity it forced us to ask several fundamental questions about the relationship between the laws of thermodynamics that describe cooling, and the quantum mechanics, which describe reality at the fundamental...

V podkastu “A res, tega ne veš?” je praznik, dobesedno!!! Ana Praznik! Voditeljica, častna zidarka in Bepopovka se je oglasila pri nas, ko je Aleš vprašal: “Kdo ali kaj je Mpemba efekt?!?!?!?” … Klikneš, poslušaš, izveš! Ti je podkast všeč? Lahko ga podpreš tukaj

In this full 3-hour live edition of "The Court of Public Opinion," Jeremy Cordeaux hosts a series of discussions with various guests, covering a wide range of topics from local and international politics to scientific discoveries and industry challenges. Here's a summary of the main topics covered: Introduction and Casual Banter: Jeremy and his co-hosts engage in light-hearted conversation, including historical anecdotes and personal stories. French Revolution and Bastille Day: Discussion on the historical significance of Bastille Day and the French Revolution. Real Estate Market: Commentary on the current state of the real estate market in Sydney and comparisons to high-value properties in Europe. Truck Driver Shortages: Interview with Warren Clark, CEO of the National Road Transport Association, about the critical shortage of truck drivers in Australia. U.S. Politics: Analysis of Joe Biden's performance and the broader implications of aging politicians. Geopolitical Tensions: Discussion on NATO's strategic role, the conflict in Ukraine, and the rising influence of China. Historical and Scientific Insights: Interview with Dr. John Bruni on stoicism, philosophy, and recent elections in France and the UK. Climate Change and Volcanic Activity: Insights from Professor Ian Plimer on climate change, volcanic activity, and scientific phenomena like black holes and the Mpemba effect. Microplastics and Public Health: Concerns about microplastics in everyday products and their potential impact on health. Historical Figures and Inventions: Remembrance of historical figures and inventions, including the HMS Endeavour and George Eastman's contributions to photography. See omnystudio.com/listener for privacy information.

En el episodio de hoy de "10 Minutos con Sami", exploramos tres fascinantes temas tecnológicos y científicos. Comenzamos con el impresionante crecimiento de Threads, la plataforma de Meta, que ha alcanzado 175 millones de usuarios activos mensuales en menos de un año. Luego, nos sumergimos en el intrigante efecto Mpemba, un fenómeno donde, bajo ciertas condiciones, el agua caliente se congela más rápido que la fría, desafiando nuestras intuiciones sobre la física. Finalmente, analizamos la tendencia emergente de los centros de datos alimentados por energía nuclear, explorando cómo gigantes tecnológicos como Amazon están invirtiendo en esta solución para satisfacer sus crecientes demandas energéticas de manera sostenible. Acompáñanos en este viaje a través de las redes sociales, la física curiosa y las innovaciones energéticas que están dando forma al futuro de la tecnología. Fuentes: https://www.axios.com/2024/07/03/meta-threads-1-year-anniversary , https://www.quantamagazine.org/does-hot-water-freeze-faster-than-cold-physicists-keep-asking-20220629/ , https://www.ans.org/news/article-5842/amazon-buys-nuclearpowered-data-center-from-talen/ Redes: Puedes buscarme por redes sociales como Threads, Twitter e Instagram con @olivernabani, y puedes encontrarme habitualmente en Twitch: http://twitch.tv/olivernabani Puedes encontrar tanto este Podcast como otro contenido original en YouTube: https://youtube.com/olivernabani Además si quieres participar en la comunidad mashain, tenemos un server de Discord donde compartimos nuestras inquietudes: https://discord.gg/7M2SEfbF Un canal de Telegram donde os aviso de novedades y contenidos: https://t.me/sedicemashain Y un canal de Whatsapp: https://whatsapp.com/channel/0029VaCSKOzFCCoavMoLwX43 Y por supuesto lo más importante, recuerda: No se dice Machine, se dice Mashain

Premiären av det lyckliga slutet är avklarat och Pernilla pustar ut. Hörde vi succé? Sofia tog med sig podmikrofonen och kollade vad Bianca och Benjamin tyckte om mammas prestation. Hur reagerade Bauer på att showen innehöll tre Christian? Mpemba effekten fascinerar. Sofia är laktosintolerant Legogubbar och tamponger åker till rymden. Och det fanns en tid när vi båda dansade med Prince. Hosted on Acast. See acast.com/privacy for more information.

In this episode we will be discussing the octet rule and why it does not always hold true, even though it is a rule in chemistry, along with an observation that seems to defy logic called the Mpemba effect and some theories on why it occurs.

In this episode, the fellas discuss the important IDP names to know in the ACC Atlantic division. From the superstars to the sleepers they have you covered. ACC Atlantic Conference Preview Devy IDP Grind EP-71 7/17/2023 News & notes  SEC & commissioner Greg Sankey agree to an extension thru 2028 SEC Media Days kicks off today and Big12 Media Days was last week Tennessee Vols avoid bowl ban. Will pay $8m penalty and reduction of scholarships (12 over next 5 years) and vacate 11 wins from 19'-20' Northwestern Wildcats fire HC Pat Fitzgerald (hazing scandal). Free agent Ed Orgeron dispels rumors he's interested in the Northwestern job Big 12 commissioner Brett Yormark wants the conference to stay at 14 teams. Who could be the teams the conference would add? Georgia off-field issues. Ten speeding infractions since Jan 15. Athletic Dept and Jalen Carter being sued by a former staffer.  MPemba got a recent speeding ticket The ACC and the CW Network have struck a deal to air 50 ACC games, with 13 being football Thank Sponsors Trophy Smack MFL - My Fantasy League Action 247 Betting Site  5★ Topic Conference Preview Series - ACC Atlantic Boston College Eagles LB Vinny DePalma CB Elijah Jones DE Donovan Ezeiruaku DE Nolan Okpala LB Kam Arnold SAF Victor Nelson Clemson Tigers DT Tyler Davis DT Peter Woods LB Barrett Carter LB  Jeremiah Trotter Jr S Andrew Mukuba S RJ Mickens CB Nate Wiggins DE Xavier Thomas DE Tomarrion Parker Florida State Seminoles DE Jared Verse LB Tatum Bethune CB Fentrell Cypress Louisville Cardinals DE Ashton Gillotte CB Jarvis Brownlee NC State Wolfpack LB Payton Wilson CB Aydan White DE Davin Vann Syracuse Orange LB Marlowe Wax DB Bralyn Oliver LB Stephon Thompson DE Caleb Okechukwu SAF Justin Barron Wake Forest Demon Deacons LB Chase Jones S Chelen Garnes DE Jasheen Davis Next Show Topic -  Conference Preview Series ACC Coastal Division --- Support this podcast: https://podcasters.spotify.com/pod/show/daniel-cook49/support

Noticias y Tendencias del mes Estas son la Noticias y Tendencias más importantes del mes en La Industria La Guía definitiva para Dilución: https://vinepair.com/cocktail-college/cocktail-college-dilution/ La "Nueva Tendencia" de sólo 2 cócteles por persona: https://vinepair.com/articles/history-two-drinks-only-cocktails/ Nueva Botella de Macallan en Colaboración con Bentley Motors: https://www.thespiritsbusiness.com/2022/08/macallan-and-bentley-unveil-collaborative-whisky/ Nueva Botella de Tequila de 200 dólares que parece un Pretxel: https://vinepair.com/booze-news/kendall-jenners-new-tequila-pretzel/ ¿Se congela más rápido el agua hirviendo que la fría?: https://vinepair.com/articles/boiling-water-for-ice/ En la noticias y tendencias del éste mes hablamos sobre cómo dominar la dilución de nuestros cócteles incluso en pre batch, el resurgimiento de la tendencia de "sólo dos cócteles por persona", dos nuevas etiquetas (de tequila y de whisky) que dicen mucho del futuro del diseño de las botellas de bebidas alcohólicas y el efecto Mpemba que asegura que se congela más rápido el agua hirviendo que el agua fría. Links de Interés: Envíanos un mensaje de voz: https://www.speakpipe.com/DetrasDelBar Únete a la Comunidad de Telegram: https://barspeakeasy.com/comunidad Invítanos un Cóctel: https://www.buymeacoffee.com/detrasdelbar Links Mencionados en el Episodio: Canal de Twitch: https://www.twitch.tv/mezclandoexperiencias https://youtu.be/xSBycLJoeok Grupo de Telegram: https://t.me/notindustria Grupo de Podcast de Coctelería en español: https://t.me/podcocteleria Episodios Relacionados Otros links de interés: Cómprame un Cóctel: https://barspeakeasy.com/apoyo Hosting desde 4$: https://barspeakeasy.com/hosting 30 días gratis de Epidemic Sound: https://www.barspeakeasy.com/epidemic document.addEventListener("DOMContentLoaded", function() { var player = document.getElementById("player-6332322277507"); podlovePlayerCache.add([{"url":"https://barspeakeasy.com/wp-json/podlove-web-player/shortcode/post/4345","data":{"title":"GUu00cdA para la DILUCIu00d3N, dos Cu00d3CTELES por PERSONA y NUEVAS ETIQUETAS de lujo","duration":"00:13:32","link":"https://www.barspeakeasy.com/podcast/guia-para-la-dilucion/","poster":"https://www.barspeakeasy.com/wp-content/uploads/portada-6-scaled.webp","audio":[{"mimeType":"audio/x-m4a","url":"https://archive.org/download/ep62-1/EP62.m4a","size":"9974875","title":"AUDIO/X-M4A"}],"chapters":[],"show":{"title":"Detru00e1s del Bar","subtitle":"Noticias y Tendencias en Cocteleru00eda","link":"https://www.barspeakeasy.com"},"transcripts":[]}}, {"url":"https://barspeakeasy.com/wp-json/podlove-web-player/shortcode/config/episodios/theme/episodico","data":{"activeTab":"chapters","subscribe-button":{"feed":"https://www.barspeakeasy.com/podcast/feed/","clients":[{"id":"spotify","service":"7ascjOfw0IulBwhzQLI5U8"},{"id":"overcast",

Noticias y Tendencias del mes Estas son la Noticias y Tendencias más importantes del mes en La Industria La Guía definitiva para Dilución: https://vinepair.com/cocktail-college/cocktail-college-dilution/ La "Nueva Tendencia" de sólo 2 cócteles por persona: https://vinepair.com/articles/history-two-drinks-only-cocktails/ Nueva Botella de Macallan en Colaboración con Bentley Motors: https://www.thespiritsbusiness.com/2022/08/macallan-and-bentley-unveil-collaborative-whisky/ Nueva Botella de Tequila de 200 dólares que parece un Pretxel: https://vinepair.com/booze-news/kendall-jenners-new-tequila-pretzel/ ¿Se congela más rápido el agua hirviendo que la fría?: https://vinepair.com/articles/boiling-water-for-ice/ En la noticias y tendencias del éste mes hablamos sobre cómo dominar la dilución de nuestros cócteles incluso en pre batch, el resurgimiento de la tendencia de "sólo dos cócteles por persona", dos nuevas etiquetas (de tequila y de whisky) que dicen mucho del futuro del diseño de las botellas de bebidas alcohólicas y el efecto Mpemba que asegura que se congela más rápido el agua hirviendo que el agua fría. Links de Interés: Envíanos un mensaje de voz: https://www.speakpipe.com/DetrasDelBar Únete a la Comunidad de Telegram: http://detrasdelbar.com/comunidad Invítanos un Cóctel: https://www.buymeacoffee.com/detrasdelbar Links Mencionados en el Episodio: Canal de Twitch: https://www.twitch.tv/mezclandoexperiencias https://youtu.be/xSBycLJoeok Grupo de Telegram: https://t.me/notindustria Grupo de Podcast de Coctelería en español: https://t.me/podcocteleria Episodios Relacionados Otros links de interés: Cómprame un Cóctel: http://detrasdelbar.com/apoyo Hosting desde 4$: http://detrasdelbar.com/hosting 30 días gratis de Epidemic Sound: http://detrasdelbar.com/epidemic [podlove-web-player post="4345"] ¿Te gustaría que te avisemos cuando salga un nuevo episodio SUSCRIBETE AQUÍ Tu aporte ayuda a mantener este podcast

Water runs through our lives

Mpemba è oggi una giovane donna capace di sorridere di fronte alle difficoltà della vita. Era soltanto una bambina quando è dovuta fuggire dalla repubblica Democratica del Congo con sua madre e il fratellino. Arrivata in Italia all'età di 13 anni si è scontrata con una nuova cultura e una nuova società poco avvezze alle buone pratiche dell'accoglienza e dell'integrazione. Era chiaro già dai primi giorni del suo arrivo in un piccola cittadina dell'Italia centrale che Mpemba non sarebbe mai ritornata nel suo paese d'origine, eppure il suo inserimento in Italia è stato difficile per gli ostacoli della lingua, del clima e - inutile ometterlo - per il colore della sua pelle. Dopo vent'anni in Italia, Mpemba è perfettamente inserita nel suo nuovo paese, ha una figlia nata in Italia, formata nelle scuole statali, mai stata in un'altro paese e che non riesce a capire perché sia considerata straniera. Una storia che racconta il percorso d'integrazione di molti nuovi italiani, ancora senza cittadinanza. Non Mi Chiamo Rifugiato è una trasmissione ideata e realizzata da Stefano Leszczynski per la Radio Vaticana, in collaborazione con il Centro Astalli di Roma. La musica della sigla è stata composta e realizzata da Luca Leszczynski. Puoi ascoltare tutti i podcast di Radio Vaticana - Vatican News cliccando qui: https://www.vaticannews.va/it/podcast.html

Escucha --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app

Episode: 2100 The Mpemba Effect: heating water to make it freeze faster.  Today, another look at an old claim.

In which scientists from Aristotle up to modern-day Tanzania try to understand the paradoxical way seems to freeze, and Ken thinks baseball should have cheerleaders. Certificate #25481.

¿Sabes en qué consiste el Efecto Mpemba? Te lo cuenta nuestra divulgadora científica de Proyecto Kennis Patricia Martínez-Lope.

Sıcak su gerçekten de bazı durumlarda soğuk sudan daha hızlı donabilir. Yüzyıllar önce Aristo, Bacon ve Descartes tarafından gözlemlenen bu durum 1963'te Tanzanya'da yaşayan Erasto Mpemba isimli öğrenci sayesinde bilim dünyasında tekrar tartışma konusu olmuştu. Bu durum, dondurma yapmak için hazırladığı sıcak süt karışımını sınıf arkadaşının hazırladığı daha soğuk karışımla birlikte buzdolabına koyduğunda, sıcak sütün soğuk sütten daha hızlı donduğuna dikkat eden Erasto Mpemba'ya ithafen “Mpemba etkisi” olarak adlandırılıyor.

Substantiv

Heute redet Sam darüber, ob heißes Wasser vielleicht schneller gefriert als kaltes und wie das mit den thermodynamischen Gesetzt überhaupt nicht zu vereinbaren ist. Zudem erklärt Caro das Kleine Welt Phänomen: Ist unsere Welt nur ein Dorf? Über wieviele Ecken kennen wir jede beliebige Person? Nächste Folge nehmen wir dann mit einem ganz neuen Podcast Setup auf, finanziert from your one and only Coronakindergeldsonderzahlung. Quellen: Mpemba Effekt Burridge, H. C. and Linden, P. F. (2016) Questioning the Mpemba effect: hot water does not cool more quickly than cold. Nature. Sci. Rep. 6, 37665; doi: 10.1038/srep37665 . Burridge H. C. and Hallstadius O. (2020) Observing the Mpemba effect with minimal bias and the value of the Mpemba effect to scientific outreach and engagement Proc. R. Soc. A.476: 20190829 doi: https://doi.org/10.1098/rspa.2019.0829 Kleine Welt Phänomen https://www.spiegel.de/wissenschaft/mensch/ueber-6-6-ecken-das-jeder-kennt-jeden-gesetz-a-569705.html> https://de.wikipedia.org/wiki/Kleine-Welt-Ph%C3%A4nomen Leskovec, J., & Horvitz, E. (2008, April). Planetary-scale views on a large instant-messaging network. In Proceedings of the 17th international conference on World Wide Web (pp. 915-924).

A new controlled experiment adds more evidence for the counterintuitive Mpemba effect of heat transfer which actually was postulated originally by Aristotle.

Coronavirus conundrum: how best to block to the spread of the virus. Also, we discuss insect and spider bites, why plastic is such a problem for the oceans, the Mpemba effect - why hot water might freeze faster than cold water - and whether vitamins and supplements can boost your immune system... Like this podcast? Please help us by supporting the Naked Scientists

Coronavirus conundrum: how best to block to the spread of the virus. Also, we discuss insect and spider bites, why plastic is such a problem for the oceans, the Mpemba effect - why hot water might freeze faster than cold water - and whether vitamins and supplements can boost your immune system... Like this podcast? Please help us by supporting the Naked Scientists

Jodeldi-ho! Hallo Otto! (Hallo Echo!) SCHNAUZE! Moin, hier ist Jonas Brinkmann, ich bin der Produzent von den beiden menschgewordenen Videospiel-Tutorials. Ich muss mich hier einmal einschalten, weil ich alle Hörer warnen muss. Es ist keine Überraschung, dass Marc und Christian uneheliche Söhne von Otto, dem Außerfriesischen sind, und ihr ganzes Comedy-Repertoire aus dieser Blutlinie stammt. Wer also eine Allergie gegen Witze hat, die dem Erdkern gefährlich nahe kommen, und Mario Barth nicht für den größten Enthüllungsjournalisten seit Claas Relotius hält, sollte also schnell ausschalten und eine Folge Paw Patrol schauen! Die Entschuldigung der Woche geht an die komplette #metoo-Bewegung, Marc hat erst nach der Aufnahme den Namen Louis CK gegooglet.

Met humor, én kennis van zaken, bespreken Rick en Dennis iedere 2 weken uiteenlopende onderwerpen waarvan je niet eens wist dat je ze wilde weten (maar die zo van pas komen op dat naderende feestje of in die stille wachtkamer!). Van basalt tot botersmokkel en van het Mpemba-effect tot Mata Hari, geen onderwerp wordt geschuwd. Abonneer vast op: https://lekkeruitgelegd.nl

Let's say you put two containers of water in a freezer. Water in one container is at room temperature, while water in the other container is hot. Which one will freeze first? Many people would understandably assume the cooler water would be the first to freeze -- and that assumption, oddly, would prove to be incorrect. Join the guys as they delve into the story and struggle of young Erasto Mpemba, the student for whom the Mpemba effect is named, exploring his initial experiments all the way to the ongoing controversy over this strange phenomenon. Learn more about your ad-choices at https://news.iheart.com/podcast-advertisers

Will you get ice cubes faster if you fill the tray with hot water?

If you want to freeze some water, you might want to heat it up first.

Serier nu för tiden har snygga intron; Westworld. Penny Dreadful. Kontraintuitiva saker: Varmt vatten fryser snabbare än kallt vatten (Mpemba-effekten). Men, kanske inte. Universums expansion accelererar. Trump vann valet. Vinst-talet, där han vände ryggen till sin kampanj. SD får väljare trots järnrör. Karta över valresultatet i Tennessee. Karta över valresultatet i New York State. Feedback […]

Solids, liquids, gases & how they transform The 'classical' states of matter (solid, liquid, gas, plasma) "are distinguished by changes in specific heat capacity, pressure & temperature" (Wikipedia) Pic: Transitions between the four fundamental states of matter - this is mostly what Johnny is talking about (Wikipedia) There's LOADS of other states of matter (modern & high-energy), but you don't see them lying around, e.g. they're made in stars or particle accelerators (Wikipedia) A 'Bose-Einstein condensate' is an example of a modern state of matter (Encyclopaedia Britannica) What is a solid? (Wikipedia) What is a liquid? (Wikipedia) What is a gas? (Wikipedia) What is plasma? (Wikipedia) What is steam? (Wikipedia) What is vapour? (Wikipedia) What is a cloud? A mass of water droplets, ice crystals, or a mix of both, suspended in the air (Encyclopaedia Britannica) The anatomy of a rain drop (Precipitation Education, NASA) The different states of matter have different properties (Purdue Science, Department of Chemistry) The different states of matter have different properties (Bitesize, BBC) State changes usually involve heating, cooling or changes in pressure (Bitesize, BBC) What is freezing or solidification? The point where any liquid turns into a solid, not just water (Wikipedia) What is boiling? (ChemWiki, UC Davis) The Fahrenheit, Kelvin & Celsius temperature scales (Department of Physics, University of Oregon) What is melting point? (Wikipedia) Some famous temperatures in Celsius, Kelvin & Fahrenheit (Wikipedia) The Fahrenheit scale (Wikipedia) The Kelvin scale (Wikipedia) What is absolute zero? (Encyclopaedia Britannica) The journey to the other side of absolute zero (IFL Science) Mercury melts at -38.87 & boils at 356.58 degrees Celsius (ChemicalElements.com) What does frozen mercury look like? (TauFlederMaus, YouTube) Mercury in the food chain (Government of Canada) Quicksilver is another name for mercury (Wikipedia) Freezing a Koosh ball in liquid nitrogen (Jefferson Lab, YouTube) Eau-Di-Vie offers martinis cooled by liquid nitrogen (Eau-Di-Vie) Gelato flash frozen by liquid nitrogen (N2 Extreme Gelato) Condensation means going backwards from gas to liquid (Wikipedia) How is lava created? (Wonderopolis) Sublimation means going straight from a solid to a gas (Wikipedia) Snow & ice can 'sublime' (Wikipedia) Gif: Atoms/molecules in solids (touching, can't move), liquids (touching, can move), gases (not touching, moving) (Purdue Science, Department of Chemistry) Pic: Atoms/molecules in solids (touching, can't move), liquids (touching, can move), gases (not touching, moving) (Bitesize, BBC) CarlCox.com Glastonbury Festival What is gas diffusion & effusion? (Boundless) Energy, vibrations & bonding during phase changes (Zona Land Education) What is a joule? (Wikipedia) From zeptojoules to yottajoules: Definitions of what different amounts of joules do (Wikipedia) What is a calorie? (Wikipedia) Water's temperature curve is linear except at the phase changes from ice to liquid to gas (Boundless) Phase changes & energy conservation: Temperature increases linearly until melting & boiling points (Boundless) A 'phase' of matter is a "region of space throughout which all physical properties of a material are essentially uniform" (Wikipedia) A 'phase' of matter is different to a 'state' of matter: A system can contain several phases of the same state of matter (Wikipedia) The law of conservation of energy in simple terms (Explain That Stuff!) When you do a reverse phase change, e.g. liquid to solid, energy is released (Boundless) What is entropy? (Science 2.0) Entropy is simple - if we avoid the briar patches! (Frank L. Lambert, Professor Emeritus, Chemistry) "In solids, atoms are bonded fairly firmly together, though they do move about a bit" (Explain That Stuff!) Electrons can travel in a solid even if the atoms can't (e.g. in conductors) (HyperPhysics, Georgia State University) Conductors, insulators & electron flow: Appears to support Johnny's electricity story about "holes moving down the wire at walking pace" (All About Circuits) Electrons only move about 1.2 cm per minute in standard home copper wire (Department of Physics, Union University) What is an electron hole? Debating how many molecules make a droplet (Physics Forums) Debating how steam is invisible vs water vapour (The Naked Scientists) Why is a steam burn more damaging than a burn with boiling water of the same temperature? (UCSB Science Line) The 'Mpemba' effect: In some circumstances warmer water may freeze faster than colder water (Wikipedia) Does hot water freeze faster than cold water? (livescience) The phase diagram for water is different than for other substances (chemguide) The phase diagram for water is different than for other substances (Chem Wiki) Water is weird: Its solid is less dense than its liquid - i.e. ice floats in liquid water - other stuff doesn't do this (Wikipedia) Water is weird: Its solid is less dense than its liquid - i.e. ice floats in liquid water - other stuff doesn't do this (Boundless) Clip: What if ice didn't float? Explained by chemist Martyn Poliakoff (The Huffington Post) What is liquefaction? (Wikipedia) Clip: The amazing Richard Feynman talks magnets (nebulajr, YouTube) How does a glacier move? It sounds like ice under pressure creating lubricating melt water does play a role (Geology.com) Johnny's heavy egg vs light jelly bean shaking experiment sounds legit (APS Physics) 'Granular convection' & the Brazil Nut Effect: Why the biggest nuts rise to the top (io9) What is vaping? (Vaper Soul) The 1755 Lisbon earthquake (Wikipedia) What was left of Lisbon was demolished & rebuilt according to modern urban design at the time (Wikipedia) The rebuilding of Lisbon involved one of the first uses of pre-fabricated buildings (History) The Anglo-Portugese treaty dates back to the 1300s...until Brexit? (Wikipedia) Quicksand science: Why it traps & how to escape (National Geographic) What is a non-Newtonian fluid? Examples include honey, cream & tomato sauce (Science Learning Hub) What is pitch? (Wikipedia) The pitch drop experiment: Watch for the tenth drop live! (The University of Queensland) The ‘glass is a liquid' myth has finally been destroyed (io9) What is steampunk? (The Huffington Post) NealStephenson.com Jumpin' Jack Flash is a gas, gas, gas (Menmo Music Station, YouTube) The Leidenfrost effect: Not really related to our chat, just cool - it's why balls of water zip around on a hot surface (Wikipedia) Corrections Water vapour is not steam: "Vapour refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance", "A liquid or solid does not have to boil to release a vapour" (Wikipedia) Debating the finer points between vapour, steam & gas (Quora) Johnny's definition of Celsius was used until 1954. The current version is "the unit 'degree Celsius' & the Celsius scale are currently defined by two different temperatures: absolute zero, & the triple point of VSMOW (specially purified water)" (Wikipedia) Probably best not to swirl your finger around in mercury kids, just in case (WHO) Nitrogen gas makes up 78% of our atmosphere, not 74% (Wikipedia) Nitrogen melts at -209.9 & boils at -195.8 degrees Celsius (ChemicalElements.com) Sorry Johnny, Ashford & Simpson sang Solid As A Rock, not Tina Turner (Fox News Entertainment) Clarifying Johnny's definitions of solid, liquid & gas by volume & shape (Glen Research Center, NASA) It's 1 calorie that raises 1cm^3 by 1 degree Celsius at 1 atmosphere, not 1 joule. However, this is an older definition & a calorie is now defined in joules (Encyclopaedia Britannica) There appears to be conjecture that entropy should be associated with 'randomness'...but it's over my head so I'll leave it there for now (Science 2.0) Sorry Johnny, there may be a new theory about why ice is slippery & how ice skating works - frictional heating - but the jury is still out (Wikipedia) Cheeky review? (If we may be so bold) It'd be amazing if you gave us a short review...it'll make us easier to find in iTunes: Click here for instructions. You're the best! We owe you a free hug and/or a glass of wine from our cellar

You Asked, We Answered! Transcript of the podcast You asked, we answered. What is the mpemba effect? Let’s first start out with who and how this discovery was made. Erasto Mpemba is the one who discovered the mpemba effect. Erasto is a Tanzanian high school student, that is famous for the Mpemba effect [3]. Mpemba’s observations confirmed some of history’s most revered thinkers, such as Aristotle, Rene Descartes and Francis Bacon, they all believed that hot water froze faster than cold water [2]. This was all observed through Erasto’s experiment that he discovered the Mpemba effect. Here is how Mpemba discovered this effect. It all started out with an experiment in his classroom. Most of the students in the room would create a mixture of ice cream. And one day a student arrived late to class and saw other students mixtures were already boiling. The students allowed their mixture to cool after it was boiling hot. After it had cooled down, they would all rush to the refrigerator for a space in the fridge. Another classmate arrived late as well and saw Mpemba boiling his milk and the other student quickly made his mixture with milk and sugar and poured it on to an ice tray without boiling it, so he wouldn’t miss his chance to having a spot in the fridge [2]. After Mpemba saw this, he decided to risk ruining the fridge by putting hot milk into it. As they tried to allow the ice cream to form, the went back an hour later to check on their product and found out that Mpemba’s tray of milk had frozen into ice cream, while his classmates mixture was still only a thick liquid, not yet frozen. Since his discovery, he talked to the professor Dr. Osborne from Dar es Salaam University and the professor performed the same experiment with different materials and came up with similar results as Mpemba [2]. It then made it to modern history, known at the Mpemba effect. However, what causes hot water to freeze faster than cold water? Well, evaporation is the strongest candidate to explain the Mpemba effect. As hot water is placed in an open container, the water begins to cool, and the overall mass decreases as some of the water evaporates [3]. Another idea that leads to hot water freezing faster than cold is because of convective heat transfer. When a liquid is heated, it can form convection currents that rapidly bring the hot liquid to the surface, where the heat is lost by evaporation. Professor Osborne noted that this convection will keep the top of the liquid hotter than the bottom, even when the temperature matches an initially cold liquid that doesn’t possess this convection cooling. This results in a faster rate of cooling that could, under the right circumstances, result in Mpemba’s observation [3]. Dissolved gas can also play a part in Mpemba’s effect, hot water can hold less dissolved gas than cold water, and large amounts of gas escape upon boiling. So, the initially warmer water may have less dissolved gas than the initially cooler water. It has been speculated that this changes the properties of the water in some way, perhaps making it easier to develop convection currents (and thus making it easier to cool), or decreasing the amount of heat required to freeze a unit mass of water, or changing the boiling point [1]. Scientist today are still figuring out the Mpemba effect and how it really works, this study of the Mpemba effect is still on going today, thank you for listening. (This audio file was recorded by Jailene Olmedo, undergraduate student at Penn State Brandywine, on April 9, 2016. References are in attached transcript.) https://www.paesta.psu.edu/podcast/what-mpemba-effect-paesta-podcast-series-episode-16

La pregunta de hoy está basada en una historia que tuvo su origen en 1963, en Magamba Secondary School, en la ciudad de Tanga, Tanzania. Allí, algunos alumnos acostumbraban a hacer helados y, para ello, hervían leche, le añadían azúcar y esperaban a que la mezcla se enfriara a temperatura ambiente antes de ponerla en el congelador del frigorífico. Un día, el estudiante de tercer curso Erasto Mpemba, descubrió, por casualidad, que si ponía la leche hirviendo directamente en el congelador, en lugar de esperar a que se enfriara, se congelaba más rápido que la leche fría. Preguntó el por qué a sus profesores, pero no le hicieron caso. Hasta que Denis Osborne, profesor de física en el University College de Dar es Salaam, visitó el colegio y escuchó la pregunta. Osborne realizó los primeros experimentos encaminados a explicar lo que ahora es conocido como “Efecto Mpemba”.

Uma breve história do Efeito Mpemba: http://www.rsc.org/mpemba-competition/mpemba-competition-history.asp O paper do próprio Mpemba: http://www.rsc.org/images/Cool-Mpemba-Osborne1969_tcm18-222099.pdf O próprio Mpemba falando sobre o efeito: https://www.youtube.com/watch?v=dOAUdJR0SIo Grandes nomes da ciência: http://ceticismo.net/2011/01/11/grandes-nomes-da-ciencia-erasto-mpemba/ Efeito Mpemba no wikipedia: https://pt.wikipedia.org/wiki/Efeito_Mpemba Congelamento curioso: http://chc.cienciahoje.uol.com.br/congelamento-curioso/ Trabalho de Nikola Bregović: http://www.rsc.org/images/nikola-bregovic-entry_tcm18-225169.pdf

Good morning Yassers! We’re trying something new at Yet Another Science Show called our Science Minute. No time to explain it (that’s the point!) so just give her a listen and let us know what you think. And don’t you … Continue reading →