minutephysics

Two Paradoxes of Space Navigation

Jun 4, 2026

Anker’s new PowerIQ 5.0 intelligent chargers are smaller and more efficient: https://shop.anker.com/Xk2OAQ | https://ankerfast.club/wt97e2 #AnkerTech This video looks at the counter-intuitive weirdness of navigating two "simple" space manoeuvres, and was inspired by this blog post by Avi: https://smorgasb.org/orbital-speed-paradox/ Brachistochrone over at Vsauce : https://youtu.be/skvnj67YGmw Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner

The Magic of Thorium Nuclear Reactors

May 12, 2026

See Copenhagen Atomic's progress towards real commercial Thorium energy here: https://www.copenhagenatomics.com This video looks at how thorium reactors generate more fissile material than they consume! REFERENCES - Thermal breeder reactors: https://doi.org/10.1146/annurev.ns.22.120172.001533 - Thorium reactor: https://www.ans.org/pubs/proceedings/article-59521/ - World Nuclear Association: https://world-nuclear.org/information-library/current-and-future-generation/thorium Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner

Is Perfect Prediction Possible?

Apr 15, 2026

A response to Veritasium's video on Newcomb's Paradox. See my full conversation with Derek over on the MinutePhysics patreon: https://www.patreon.com/cw/minutephysics See Derek's original video over on the Veritasium channel: https://www.youtube.com/watch?v=Ol18JoeXlVI REFERENCES - Newcomb's Paradox: https://doi.org/10.1007/978-94-017-1466-2_7 - Quantum solution: https://doi.org/10.48550/arXiv.quant-ph/0202074 - Quantum causality: https://doi.org/10.1103/PhysRevX.7.031021 - https://www.pokutta.com/blog/newcomb-four-lenses/ - https://scottaaronson.blog/?p=30  - Veritasium video references Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner 00:00 Intro 00:51 Newcomb's Paradox 02:01 One Box vs. Two Boxes 03:02 Causal Calculus 04:17 Intervention 05:45 Perfect Prediction 07:32 Quantum Mechanics 09:39 Henry's Thoughts 11:11 What Should You Choose? 12:09 Join MinutePhysics! 12:28 Derek's Thoughts

Do *you* understand ISO?

Mar 11, 2026

Help stop the worst parts of factory farming: http://www.farmkind.giving/minute-physics?promo=minute_physics This video explains how ISO is very different to what most people imagine, and how you can use this knowledge to take less noisy photos! REFERENCES - Sensor Analysis Primer: https://www.photonstophotos.net/GeneralTopics/Sensors_&_Raw/Sensor_Analysis_Primer/Photographic_Dynamic_Range_Shadow_Improvement.htm - Image sensors explained: https://www.canon-europe.com/pro/infobank/image-sensors-explained/ Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner Chapters 0:00 Misunderstanding ISO 1:54 ISO Explained 3:20 Why Even Have ISO? 4:52 What Actually Creates Noise 7:12 ISO Step-by-Step Guide! 8:36 Sponsor Message from FarmKind 9:43 ISO Caveats

Is Quantum Mechanics Stopping Aliens From Contacting Us?

Feb 11, 2026

Sign up for Brilliant for free and get 30 days of full access to all of their courses here: https://Brilliant.org/MinutePhysics. You’ll also get 20% off an annual Premium subscription for all of Brilliant’s content. Thanks to Brilliant for their support. This video explains how the Fermi Paradox - the fact that aliens should mathematically be abundant in the universe and yet we haven't heard from any - actually makes sense when you take into account quantum technology. REFERENCES - On Interstellar Quantum Communication and the Fermi Paradox: https://doi.org/10.48550/arXiv.2408.02445 - Quantum coherence to interstellar distances: https://doi.org/10.48550/arXiv.2009.00356 - Exponential Separation of Quantum and Classical One-Way Communication Complexity for a Boolean Function: https://doi.org/10.48550/arXiv.quant-ph/0607174 - Classical Interaction Cannot Replace a Quantum Message: https://doi.org/10.48550/arXiv.quant-ph/0703215 Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner Chapters 0:00 The Fermi Paradox 0:27 Interstellar Quantum Communication 1:21 Quantum Communication Requirements 2:19 Why We Don't Hear Anything 3:07 Fermi Paradox Solution? 3:48 Sponsor Message from Brilliant 4:30 Caveats!

The REAL Reason Asteroids Aren't Planets

Jan 22, 2026

Want to restore the planet’s ecosystems and see your impact in monthly videos? The first 100 people to join Planet Wild with our code MinutePhysics1 will get their first month for free: https://planetwild.com/r/minutephysics/join If you want to get to know them better first, check out their mission about the power of peatland ecosystems: https://planetwild.com/r/minutephysics/m35 This video is about the interesting and often-misunderstood story of the asteroids, and how they lost their planet-hood status; more recently than you may think! REFERENCES - https://www.sciencedirect.com/science/article/abs/pii/S0019103518303063 - https://www.pnas.org/doi/pdf/10.1073/pnas.39.12.1159 - https://www.eoas.ubc.ca/~mjelline/453website/eosc453/E_prints/newfer010/asphaug_asteroids_AR09.pdf Link to Patreon Supporters: http://www.minutephysics.com/supporters/ 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 Produced by Joshua Chawner Chapters 0:00 Intro 0:23 Asteroid Planet Discovery 1:07 Asteroid Planet Reaction 1:48 Why Asteroids are Not Planets 3:09 Demotion of the Asteroids 3:47 Sponsor Message from Planet Wild!

An Argument The Moon is a PLANET!

Dec 22, 2025

Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics
 This video is about how the International Astronomical Union's definition for a planet is flawed, even if you take it at face value! The moon almost counts as a planet according to their definition, even though they don't want it to... REFERENCES MinutePhysics video about the moon's orbit: https://www.youtube.com/watch?v=KBcxuM-qXec IAU 2006 Resolutions: https://iauarchive.eso.org/news/pressreleases/detail/iau0603/ Paper arguing moon satisfies IAU criteria: https://doi.org/10.4236/ijaa.2017.74024 https://doi.org/10.3847/PSJ/ad4edd BEST paper about planet definition history: https://doi.org/10.1016/j.icarus.2021.114768 https://doi.org/10.1017/S1539299600013289 IAU exoplanet working definition: https://doi.org/10.1017/S1539299600013289 Link to Patreon Supporters: http://www.minutephysics.com/supporters/
 
 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 Produced by Joshua Chawner Chapters 0:00 The IAU's definition of "Planet" 0:23 Criteria a) "Orbits the sun" 0:53 Criteria b) "is round" 1:28 Criteria c) "clears its orbit" 2:38 Criteria X) "not a moon" 2:59 Criteria "Footnote" - "must be on the list" 3:42 The Purpose of defining "planets" 4:16 So, what is a planet?

The TROJAN Test

Dec 3, 2025

The MinutePhysics t-shirt bundle is available now: https://store.dftba.com/products/physics-t-shirt-bundle How do we truly know if something is orbiting something else? You may be familiar with the barycenter test, but you may not have heard of the better "Trojan test"! Further reading: - https://science.nasa.gov/resource/what-is-a-lagrange-point/ - https://www.sciencedirect.com/science/article/pii/S138764732200001X - https://map.gsfc.nasa.gov/ContentMedia/lagrange.pdf - https://iopscience.iop.org/article/10.3847/PSJ/ad55f3 Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner 00:00 Intro 00:15 Barycenter Test Problems 02:18 Trojan Points 03:20 Trojan Stability 04:00 The Trojan Test 04:21 Trojan vs. Barycenter 05:16 Trojan Test Usefulness 05:45 Earth - Moon System 06:03 DFTBA Physics Shirt Bundle!

Why Some Rainbows Turn White

Oct 24, 2025

Download Opera for free: https://opr.as/Opera-browser-minutephysics Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics
 If you wander outside on a misty morning you may come across a white rainbow - called a fogbow! White rainbows need three things to form: mist, the sun, and you. White rainbows are the same as regular rainbows, except they only form when the water drops in the air are super small. To find a white rainbow, go out when the Sun is low in the sky, like in the morning or evening. You want the Sun to be behind you so that a ~40 degree angle from the droplet to you and the sun is achievable. You'll need to be in a very thin fog, thin enough that the sun shines through but thick enough to reflect the sun's light back. Look away from the sun (the same way you do with a regular rainbow). REFERENCES: Mie theory, Airy theory, and the natural rainbow - https://opg.optica.org/ao/abstract.cfm?uri=AO-37-9-1506 Physically-based simulation of rainbows - https://dl.acm.org/doi/abs/10.1145/2077341.2077344 Veritasium video about rainbows: https://www.youtube.com/watch?v=24GfgNtnjXc Link to Patreon Supporters: http://www.minutephysics.com/supporters/
 
 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!
 
 Created by Henry Reich Produced by Joshua Chawner 00:00 Opera Sponsorship 00:03 Fogbow Introduction 00:31 Rainbow Recap 01:07 Raindrop Reflected Waves 02:08 Large Droplet Rainbow 02:18 Small Droplet Supernumerary Bows 02:45 Tiny Droplet Fogbow 03:02 Conclusion 03:10 Lee Diagrams 03:28 Opera Sponsorship

Common Moon Mistakes

Oct 3, 2025

Support MinutePhysics on Patreon! https://patreon.com/minutephysics The moon is a familiar sight - yet it is rarely illustrated correctly. This video will show you how to get it right! Further reading: - https://www.youtube.com/watch?v=KBcxuM-qXec - https://www.youtube.com/watch?v=pAI1N96t8Vk - https://www.youtube.com/watch?v=T3gacnHb9TI - https://www.youtube.com/watch?v=7mb3AQmhTKo Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner 00:00 Intro 00:25 Wrong Shape 01:24 Wrong Transparency 02:03 Wrong Lighting 02:29 Wrong Time Of Day / Night 02:59 Wrong Orientation 03:30 Lion King Example 04:22 How To Get It Right! 04:44 Ps...

Why Do Wind Turbines Have Three Blades?

Sep 12, 2025

Join us to celebrate our sun (and wind!) powered planet on Sept. 21 - more info at https://www.sunday.earth/ Support MinutePhysics on Patreon! https://patreon.com/minutephysics Wind turbines are a successful and popular method to create clean energy. But why do almost all of them have 3 blades? Here are 3 reasons. Further reading: - The Wind Hand Book, Tony Burton et al., 2001 - The Effect of the Number of Blades on the
 Efficiency of A Wind Turbine, Kehinde Adeseye Adeyeye et al., 2020 - https://www.youtube.com/watch?v=WGKIjojADmg - https://www.youtube.com/watch?v=CI-bwqhhTTw Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner

Draining The Oceans Is HARD

Sep 5, 2025

Use Ground News to understand the news better, avoid media bias, and prioritize factuality. Use this link to get 40% off your subscription: https://ground.news/physics Support MinutePhysics on Patreon! https://patreon.com/minutephysics It's hard to drain the oceans because it's a nonlocal phenomenon. Luckily there's a clever algorithm that's similar to the "paint bucket" tool in photoshop or other image editing software that allows us to figure out where remnant ocean basins will be. Further reading: - https://www.youtube.com/watch?v=Jpy55EgMQgY - https://www.youtube.com/watch?v=FkUNHhVbQ1Q Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner 00:00 - Intro 00:50 - The 2D Problem 02:09 - The 3D Problem 04:09 - Considerations 04:52 - The 3D Solution! 05:23 - Sponsorship From Ground News 06:42 - XKCD's What If

The Physics of Supercooling

Aug 15, 2025

Support MinutePhysics on Patreon! https://patreon.com/minutephysics Further reading: - https://doi.org/10.1007/s10068-020-00750-6 - https://www.youtube.com/watch?v=_bcfxty39Cw - https://www.youtube.com/watch?v=c2wafIzuvlI Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner

White Balance is Broken

Aug 5, 2025

Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Further reading: - https://www.youtube.com/watch?v=mqZm6u12RJA - SWBNet: A Stable White Balance Network for sRGB Images by Chunxiao Li et al, 2023 - Considering Chromatic Adaptation in Camera White Balance by Minchen Wei et al, 2022 Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner 00:00 - What is White Balance? 00:49 - How is White Balance Broken? 02:03 - Why is White Balance Broken? 02:54 - Comparison with Exposure 04:55 - How to Fix White Balance 05:52 - Takeaways 06:49 - Ps...

The Physics Of Dissonance

Jul 18, 2025

Thanks to the Acoustical Society of America for sponsoring this video! Start your career in acoustics today with the ASA career toolkit: https://exploresound.org/acoustics-careers/ Get your very own ‘Harmony/Dissonance‘ t-shirt here: https://store.dftba.com/products/dissonance-tee And check out my friend Aatish’s interactive website here: https://aatishb.com/dissonance/ Further watching: - https://www.youtube.com/watch?v=1Hqm0dYKUx4 - https://www.youtube.com/watch?v=spUNpyF58BY References used for this video: - Tuning, Timbre, Spectrum, Scale by W. Sethares, 2nd Ed. 2004 - Tonal Consonance and Critical Bandwidth by R. Plomp & W. Levelt, 1965 - Auditory Patterns by H. Fletcher, 1940 - On The Sensations Of Tone by H. Helmholtz, 1875 - https://www.pharmacy180.com/article/sense-of-hearing-3587/ - https://www.sfu.ca/sonic-studio-webdav/handbook/Consonance.html - https://sethares.engr.wisc.edu/consemi.html#anchor149613 - ​​http://hyperphysics.phy-astr.gsu.edu/Music/cirmem - https://en.wikipedia.org/wiki/Piano_acoustics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics provides an energetic and entertaining view of old and new problems in physics - all in a minute! Created by Henry Reich Produced by Joshua Chawner 00:00 - Intro 01:57 - Contents 02:13 - 1) Dissonance of Pure Sine Waves 07:42 - 2) Dissonance of Notes with Overtones 11:28 - 3) Dissonance and Scales 15:29 - 3.5) Is any of this true?? 19:06 - 4) Dissonance in Chords 22:36 - Conclusion 24:15 - Sponsorship from ASA 25:03 - 5) Caveats and T-shirt!

The Magnetic Shadow Effect

Jun 26, 2025

Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich Video Producer: Josh Chawner

Antimatter in Sci-Fi Rundown

Jun 13, 2025

Get a 14-day free trail of MyHeritage at https://bit.ly/MinutePhysics_MH Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich

The Teleprompter Paradox

Feb 28, 2025

Go to https://mondly.app/minutephysics to get 95.5% off lifetime access to 41 languages and start learning today. Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich

The Chart Missing From ALL Spreadsheet Software

Nov 22, 2024

Support MinutePhysics on Patreon! https://www.patreon.com/minutephysics or Gift a Patreon membership : https://www.patreon.com/minutephysics/gift I was supposed to thank these patrons on-screen: Pierre Lanson David Adams Xierumeng Joseph Welford Jason Anaya Amnon Levi That Asymptote James Kyouhei Scott Crawford Andreas Chris Wilhelmer Patreotic Pleb Jean-Luc Cooke Emanuel Kahler rotem Andy Hsu Joe McCann Ceolifer Michael Millar Jesse Simmons Matt Darcy Tabelel Manish Kumar Myles Kornfeld John J White Long Quan Fergus Simpson Diane Lehmann Miranda P. Lee Denison barelylingual M K franspaco frowniebrownie Forged by Geeks Cody Powell J. Tower Leo Wang Tim Nodraak Joe Max DeStefano Kade Murray Condor103 donbataco NuSigma Iced Lava Rafael Alex Martin Ben Solomons Eric Pan Matthew Norman Pierre Avital Jason Hubbell Nick Kruse Jo Louie John VanderPol A Jacob Grover Water Sean Holloway Andrea Seth Lara Benham Benjamin Loftus Waldo HiggsAnyon Thomas Warfel Terry Hades Kevin Mattick Shardul Heda Danyel Cavazos Quinn Bright SL Haanschoten Zachary Condon Jason Singh Martin Kahnt Stephen Cummings CruxCapacitor Thomas Levy Tristan Bellman-Greenwood Ethan Torres Tom Schoeber Clutz Stefan Papastefanou Cary Harper Jordan Pitlor Jaques de Bois Patreon Sucks Tyler Nelson Stan Sam Wilkinson LivingInTheNow Ian Tillman Pierce Moore Caitlin Ethan Anderson Patreon Supporter Ubiquity Ventures Lukas Biewald Muhammad Shifaz Jeff Straathof Link to Patreon Supporters: http://www.minutephysics.com/supporters/ Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich

The Periodic Table in a 2D World

Nov 8, 2024

Watch Decoding the Universe: Quantum - https://bit.ly/3YU2DIf Watch the first part of this two-part series! Decoding the Universe: Cosmos - https://to.pbs.org/3YC5TGU 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

I'm giving away 14 years of drawings

Nov 1, 2024

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 Moon's Orbit is WEIRD

Oct 2, 2024

Go to https://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?

Aug 26, 2024

Go to https://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/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 Color Temperature Paradox

Jul 24, 2024

Go to https://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?

Apr 5, 2024

Check out the interactive lab here: https://labs.minutelabs.io/eclipses/ Solar 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/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 Eclipses Travel WEST to EAST?

Apr 1, 2024

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 Aren't There Eclipses Every Month?

Mar 21, 2024

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?

Dec 20, 2023

Want to donate to the highest-impact charities AND get your donation matched up to $100? Visit https://Givewell.org/MinutePhysics If 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/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ ********************************** REFERENCES Hyperphysics: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/sweat.html Engineering Toolbox Mollier Diagram: http://www.engineeringtoolbox.com/psychrometric-chart-mollier-d_27.html Sweat Info http://www.anaesthesiamcq.com/FluidBook/fl3_3.php Other 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_.html http://onlinelibrary.wiley.com/doi/10.1111/j.1748-1716.2012.02452.x/abstract http://lifehacker.com/5921036/dont-wipe-your-sweat-off-your-brow-itll-cool-you-down-faster http://www.realclearscience.com/2012/06/28/does_wiping_sweat_prevent_you_from_cooling_off_247729.html ********************************** CALCULATIONS Typical adult human body surface area ~ 1.5-2 m^2 https://en.wikipedia.org/wiki/Body_surface_area Evaporation rate at 25°C and 50% humidity, slight air movement (v~.5m/s) = .35kg/m^2/hr http://www.engineeringtoolbox.com/evaporation-water-surface-d_690.html So 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 (https://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 - @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 LAST Eclipse in History

Dec 13, 2023

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 - https://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?

Dec 6, 2023

Sign up for Brilliant (for free) and get 30 days of full access to all of their courses, go to https://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 https://doi.org/10.1007/s00371-018-1552-4 Physically-Based Real-Time Lens Flare Rendering http://doi.acm.org/10.1145/1964921.1965003 From the Series of Articles on Lens Names: Tessar, by H. H. Nasse. Carl Zeiss Camera Lens Division March 2011 https://www.cambridgeincolour.com/tutorials/lens-flare.htm https://www.toolfarm.com/tutorial/in-depth-lens-flares-for-video/ https://petapixel.com/what-is-lens-flare/ https://www.maxon.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