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PBS Space Time

PBS Space Time

PBS

Space Time explores the outer reaches of space, the craziness of astrophysics, the possibilities of sci-fi, and anything else you can think of beyond Planet Earth with our astrophysicist host: Matthew O’Dowd. For all business inquiries and sponsorship opportunities please reach out to: pbsspacetime@lighthouseagents.com Matt O'Dowd spends his time studying the universe, especially really far-away things like quasars, super-massive black holes, and evolving galaxies. He uses telescopes in space to do it. Matt completed his Ph.D. at NASA's Space Telescope Science Institute, followed by work at the University of Melbourne and Columbia University. He's now a professor at the City University of New York's Lehman College and an Associate at the American Museum of Natural History's Hayden Planetarium. Previous host Gabe Perez-Giz is an astrophysicist who studies black hole physics. He received his Ph.D. from Columbia University and also hosted PBS Infinite Series. patreon.com/pbsspacetime

809 - What is Energy?
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  • 809 - What is Energy?

    Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACEUploaded 14-02-18Energy is the most powerful and useful concept in all of physics, but what exactly is it?You can start your free trial of The Great Courses Plus at http://ow.ly/E15c30hIv7cYou can further support us on Patreon at https://www.patreon.com/pbsspacetimeGet your own Space Time t­shirt at http://bit.ly/1QlzoBiTweet at us! @pbsspacetimeFacebook: facebook.com/pbsspacetimeEmail us! pbsspacetime [at] gmail [dot] comComment on Reddit: http://www.reddit.com/r/pbsspacetimeHelp translate our videos!https://www.youtube.com/timedtext_cs_...Previous Episode:Kronos: Devourer of Worldshttps://www.youtube.com/watch?v=9-SxVSpSoek&t=1sWritten and Hosted by Matt O'DowdProduced by Rusty WardGraphics by Matthew RankerAssistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington Made by Kornhaber Brown (www.kornhaberbrown.com)In physics energy is not a substance, nor is it mystical. Energy is a number. A quantity. And the quantity itself isn’t even particularly fundamental. Instead, it’s a mathematical relationship between other, more fundamental quantities. It was 17th century polymath Gottfried Leibnitz who first figured out the mathematical form of what we call kinetic energy – the energy of motion. He realized that the sum of mass times velocity squared for a system of particles bouncing around on a flat surface is always conserved, assuming no friction and perfect bounciness. Leibnitz called this early incarnation of energy vis viva – the living force.Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big BangCoolAsCatsDavid NicklasFaisal SaudAnton LifshitsJoey RednerQuasarTambe BarsbayMayank M. MehrotaMars YenturMark RosenthalDean FuquaJustin LloydRoman PinchukHypernovaShaun WilliamsEdmund FokschanerMax LevineMatthew O’ConnorEugene LawsonMartha HuntJoseph SalomoneChuck ZegarJordan YoungRatfeastJohn HofmannBarry HatfieldCraig PetersonThanks to our Patreon Gamma Ray Burst Supporters: Jane MyersBrandon CookJames FlowersGreg AllenDenys IvanovNick VirtueAlexey EromenkoNicholas RoseScott GossettMark DykstraMark VasilePatrick MurraySultan AlkhulaifiAlex SetoMichal-Peanut KarmiErik SteinDaniel LyonsKevin WarneJJ BagnellJ RejcAvi GoldfingerJohn PettitFlorian StiglmayrBenoit Pagé-GuitardNathan LenizJessica FraleyLoro LukicBrandon LabonteDavid CraneGreg Weiss"The Great Courses Plus is currently available to watch through a web browser to almost anyone in the world and optimized for the US market. The Great Courses Plus is currently working to both optimize the product globally and accept credit card payments globally." Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

    Wed, 07 Oct 2026
  • 808 - The Death of the Sun

    Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACEUploaded 21-02-18What exactly will happen when the sun dies? You can further support us on Patreon at https://www.patreon.com/pbsspacetimeGet your own Space Time t­shirt at http://bit.ly/1QlzoBiTweet at us! @pbsspacetimeFacebook: facebook.com/pbsspacetimeEmail us! pbsspacetime [at] gmail [dot] comComment on Reddit: http://www.reddit.com/r/pbsspacetimeHelp translate our videos!https://www.youtube.com/timedtext_cs_...Previous Episode:What is Energy?https://www.youtube.com/watch?v=PUn2izowBkw&t=25sLike living things, stars have a life cycle. They’re born inside of a cloud of gas and dust, they live their lives fusing hydrogen into helium in their cores, shining bright and stable for as long as that hydrogen lasts. Then they die, each going out in its own beautiful way. How a star dies depends on its mass. The bigger they are, the shorter their lives and the more sublime their deaths. Hosted by Matt O'DowdWritten by Drew Rosen and Matt O'DowdProduced by Rusty WardGraphics by Grayson BlackmonAssistant Editing and Sound Design by Mike Petrow and Linda HuangMade by Kornhaber Brown (www.kornhaberbrown.com)Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big BangCoolAsCatsDavid NicklasFaisal SaudAnton LifshitsJoey RednerQuasarTambe BarsbayMayank M. MehrotaMars YenturMark RosenthalDean FuquaJustin LloydRoman PinchukFrank SeciliaHypernovaShaun WilliamsEdmund FokschanerMatthew O’ConnorEugene LawsonMartha HuntJoseph SalomoneChuck ZegarJordan YoungRatfeastJohn HofmannBarry HatfieldCraig PetersonThanks to our Patreon Gamma Ray Burst Supporters: Jane MyersBrandon CookJames FlowersGreg AllenDenys IvanovNick VirtueAlexey EromenkoNicholas RoseScott GossettMark DykstraMark VasilePatrick MurraySultan AlkhulaifiAlex SetoMichal-Peanut KarmiErik SteinDaniel LyonsKevin WarneJJ BagnellJ RejcAvi GoldfingerJohn PettitFlorian StiglmayrBenoit Pagé-GuitardNathan LenizLoro LukicBrandon LabonteDavid CraneGreg WeissJames HughesTJ Madison Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

    Tue, 06 Oct 2026
  • 807 - The Trebuchet Challenge | Space Time

    Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACEUploaded 28-02-18Do you have what it takes to calculate the awesome power of the trebuchet? You can further support us on Patreon at https://www.patreon.com/pbsspacetimeGet your own Space Time t­shirt at http://bit.ly/1QlzoBiTweet at us! @pbsspacetimeFacebook: facebook.com/pbsspacetimeEmail us! pbsspacetime [at] gmail [dot] comComment on Reddit: http://www.reddit.com/r/pbsspacetimeHelp translate our videos!https://www.youtube.com/timedtext_cs_panel?tab=2&c=UC7_gcs09iThXybpVgjHZ_7gPrevious Episode:Death of the Sunhttps://www.youtube.com/watch?v=iJY3y5_k0doKinetic and potential energy are defined as combinations of more basic quantities: position, velocity and mass. These combinations are chosen so that their sum is conserved. It’s actually remarkable that there’s any such combination of quantities that is conserved. This fact gives us insight into the fundamental symmetries of nature. It’s something we’ll get back to. Today I want to highlight the power of energy as a tool in calculation. We could get into fluid or stellar dynamics, or even quantum mechanics. But no, we’re going talk about something cooler – the trebuchet. If you’re not familiar, shame on you, but here’s the deal: the trebuchet is, I suppose, a type of catapult, but it’s so much more. The internet agrees that the trebuchet is the greatest of all medieval siege engines. Opinion is divided on whether Chuck Norris would win a fight against a trebuchet. The hyperbole is kind of warranted. The trebuchet is incredibly efficient at converting the potential energy of a massive counterweight into the castle-destroying kinetic energy of a projectile. It relies on the mighty power of the lever. Hosted by Matt O'DowdWritten by Matt O'DowdProduced by Rusty WardGraphics by Grayson BlackmonAssistant Editing and Sound Design by Mike Petrow and Linda HuangMade by Kornhaber Brown (www.kornhaberbrown.com)Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big BangCoolAsCatsDavid NicklasFaisal SaudAnton LifshitsJoey RednerQuasarTambe BarsbayMayank M. MehrotaMars YenturMark RosenthalDean FuquaRoman PinchukFrank SeciliaHypernovaShaun WilliamsEdmund FokschanerMatthew O’ConnorEugene LawsonMartha HuntJoseph SalomoneChuck ZegarJordan YoungRatfeastJohn HofmannBarry HatfieldCraig PetersonThanks to our Patreon Gamma Ray Burst Supporters: Kris FernetJane MyersBrandon CookJames FlowersGreg AllenDenys IvanovNick VirtueAlexey EromenkoNicholas RoseScott GossettMark VasilePatrick MurraySultan AlkhulaifiAlex SetoMichal-Peanut KarmiErik SteinDaniel LyonsKevin WarneJJ BagnellJ RejcAvi GoldfingerJohn PettitFlorian StiglmayrBenoit Pagé-GuitardNathan LenizLoro LukicBrandon LabonteDavid CraneGreg WeissJames HughesTJ Madison Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

    Mon, 05 Oct 2026
  • 806 - Should Space be Privatized? | Space Time

    Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACEUploaded 07-03-18Will the future of space exploration be guided by public or private entities? Which is better?Learn more about CuriosityStream at https://curiositystream.com/spacetimeYou can further support us on Patreon at https://www.patreon.com/pbsspacetimeGet your own Space Time t­shirt at http://bit.ly/1QlzoBiTweet at us! @pbsspacetimeFacebook: facebook.com/pbsspacetimeEmail us! pbsspacetime [at] gmail [dot] comComment on Reddit: http://www.reddit.com/r/pbsspacetimeHelp translate our videos!https://www.youtube.com/timedtext_cs_panel?tab=2&c=UC7_gcs09iThXybpVgjHZ_7gPrevious Episodes:The Trebuchet Challengehttps://www.youtube.com/watch?v=G7UOFZBEA_gDeath of the Sunhttps://www.youtube.com/watch?v=iJY3y5_k0doOn February 8th 2018, the eyes of the world once again fixed upon Cape Canaveral. This time, people watched with anticipation as SpaceX launched its new Falcon Heavy rocket. This was the first test of a rocket that may one day send people across the solar system. The near-simultaneous landing of its two booster rockets was like something out of a sci-fi flick. It looked like the future. The subsequent view of a cherry-red Tesla Roadster drifting through space was like something out of a Douglas Adams novel. The landmark launch of the Falcon Heavy rocket is a milestone in a new space race. One not between nations, but instead between private companies. Is this the best thing for the future of human space travel?Links to Comments Response:Stimulihttps://www.youtube.com/watch?v=iJY3y5_k0do&lc=UgwGa3G9okwGJbcmINV4AaABAgDethdehttps://www.youtube.com/watch?v=iJY3y5_k0do&lc=UgzPK43QbAtjm4xtYJx4AaABAgLcra Arclhttps://www.youtube.com/watch?v=G7UOFZBEA_g&lc=UgytIQalMVs5jSETirF4AaABAgHosted by Matt O'DowdWritten by Drew Rosen and Matt O’DowdProduced by Rusty WardGraphics by Grayson BlackmonAssistant Editing and Sound Design by Mike Petrow and Linda HuangMade by Kornhaber Brown (www.kornhaberbrown.com)Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big BangCoolAsCatsDavid NicklasFaisal SaudAnton LifshitsJoey RednerQuasarTambe BarsbayMayank M. MehrotaMars YenturMark RosenthalDean FuquaRoman PinchukColeslawPurdieHypernovaEdmund FokschanerMatthew O’ConnorEugene LawsonMartha HuntJoseph SalomoneChuck ZegarJordan YoungRatfeastJohn HofmannBarry HatfieldCraig PetersonKevin CostelloThanks to our Patreon Gamma Ray Burst Supporters: James HughesKris FernetJane MyersJames FlowersGreg AllenTJ MadisonDenys IvanovNick VirtueAlexey EromenkoNicholas RoseScott GossettMark VasilePatrick MurraySultan AlkhulaifiAlex SetoMichal-Peanut KarmiErik SteinDaniel LyonsKevin WarneJJ BagnellJ RejcAvi GoldfingerJohn PettitFlorian StiglmayrBenoit Pagé-GuitardNathan LenizBrandon LabonteDavid CraneGreg Weiss Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

    Mon, 05 Oct 2026
  • 805 - Hawking Radiation

    Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACEUploaded 15-03-18It’s the most famous prediction of perhaps the most famous genius of our time ... Stephen Hawking's theory of Hawking Radiation.You can further support us on Patreon at https://www.patreon.com/pbsspacetimeGet your own Space Time t­-shirt at http://bit.ly/1QlzoBiTweet at us! @pbsspacetimeFacebook: facebook.com/pbsspacetimeEmail us! pbsspacetime [at] gmail [dot] comComment on Reddit: http://www.reddit.com/r/pbsspacetimeHelp translate our videos!https://www.youtube.com/timedtext_cs_panel?tab=2&c=UC7_gcs09iThXybpVgjHZ_7gQuantum Vacuum Playlisthttps://www.youtube.com/playlist?list=PLsPUh22kYmNAHB1W2_Ka2F83sObdczwKrPrevious Episode:Should Space be Privatized?https://www.youtube.com/watch?v=wJ7d503fN-gSoon after Einstein revealed his great general theory of relativity in 1915, physicists realized that it allowed for the possibility of catastrophic gravitational collapse. In places of extreme density like the dead core of a massive star, space and time could be dragged inwards to create a hole in the universe: a boundary in spacetime called an event horizon that could be entered, but from beyond which nothing could return. Once formed, there was nothing in theory or imagination that could bring material consumed back to the outside universe. These black holes should exist forever – only growing, never shrinking.References:Black Hole Explosions?S. W. Hawking (1974) https://www.nature.com/articles/248030a0 (paywall)Particle Breation by Black HolesS. W. Hawking (1975)https://link.springer.com/article/10.1007%2FBF02345020 (paywall)https://projecteuclid.org/euclid.cmp/1103899181Hawking Radiation as TunnelingM. K. Parikh and F. Wilczek (2002)https://arxiv.org/abs/hep-th/9907001Hosted by Matt O'DowdWritten by Matt O'Dowd and Graeme GosselProduced by Rusty WardGraphics by Grayson BlackmonAssistant Editing and Sound Design by Mike Petrow and Linda HuangMade by Kornhaber Brown (www.kornhaberbrown.com)Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big BangCoolAsCatsDavid NicklasFaisal SaudAnton LifshitsJoey RednerQuasarTambe BarsbayMayank M. MehrotaMars YenturMark RosenthalDean FuquaRoman PinchukColeslawPurdieHypernovaMatthew O’ConnorEugene LawsonMartha HuntJoseph SalomoneChuck ZegarCraig PetersonJordan YoungRatfeastJohn HofmannBarry HatfieldEdmund FokschanerKevin CostelloThanks to our Patreon Gamma Ray Burst Supporters: James HughesFabian OlesenKris FernetJane MeyersJames FlowersGreg AllenTJMadisionDenys IvanovNick VirtueAlexey EromenkoNicholas RoseScott GossettMark VasilePatrick MurraySultan AlkhulaifiAlex SetoMichal-Peanut KarmiErik SteinDaniel LyonsKevin WarneJJ BagnellJ RejcAvi GoldfingerJohn PettitFlorian StinglmayrBenoit Pagé-GuitardNathan LenizBrandon LabonteDavid CraneGreg Weiss Learn more about your ad choices. Visit megaphone.fm/adchoices Learn more about your ad choices. Visit megaphone.fm/adchoices

    Sun, 04 Oct 2026
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