DO NOT TIP. This is an unofficial YouTube mirror of PBS Space Time (https://youtu.be/X5rAGfjPSWE). If you want to tip PBS Space Time please visit https://www.patreon.com/pbsspacetime/. Convince PBS Space Time to join Odysee! ----------------------------- Viewers like you help make PBS (Thank you ?) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACE It turns out that "nothing" is one of the most interesting somethings in all of physics. Signup for your free trial to The Great Courses Plus here: http://ow.ly/OOOp30beNyt Note: There is a correction in this video that has been addressed in the pinned comment below. You can further support us on Patreon at https://www.patreon.com/pbsspacetime Get your own Space Time t­shirt at http://bit.ly/1QlzoBi Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Comment on Reddit: http://www.reddit.com/r/pbsspacetime Help translate our videos! https://www.youtube.com/timedtext_cs_panel?tab=2&c=UC7_gcs09iThXybpVgjHZ_7g Previous Episode: Absolute Cold | Space Time https://www.youtube.com/watch?v=OvgZqGxF3eo Links to Comments Response: Man from Nantucket https://www.youtube.com/watch?v=OvgZqGxF3eo&lc=z22au3kgsnywi3tfuacdp43bey3x42yghxxfro3of3dw03c010c Laxmi Papney https://www.youtube.com/watch?v=OvgZqGxF3eo&lc=z221wb4gbmqozpfih04t1aokghgvqbdfhp5uaokihurork0h00410 Flo Striker https://www.youtube.com/watch?v=OvgZqGxF3eo&lc=z22exnpronzrfh4ij04t1aokgvbvlfrzle5r0scv5yx4bk0h00410 HK Norman https://www.youtube.com/watch?v=OvgZqGxF3eo&lc=z22gsnaxxkr4ht0vuacdp43b2kufaeojpztkpo35ecpw03c010c thesimulacre https://www.youtube.com/watch?v=OvgZqGxF3eo&lc=z22mxzsqdkyhuvkdkacdp433mitjuajhidaq0f5avexw03c010c How do we study nothing? An empty jar still contains something: molecules of air and a bath of infrared light from its warm environment. But what if we suck out every last molecule of air, chill the jar to absolute zero, and shield it from all external radiation? The jar would contain only empty space, but it turns out that empty space is far from nothing. Written and Hosted by Matt O'Dowd Produced by Rusty Ward Graphics by Kurt Ross Assistant Editing and Sound Design by Mike Petrow Made by Kornhaber Brown (www.kornhaberbrown.com) Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big Bang BITISM CoolAsCats David Nicklas Richard Senegor Quasar Tambe Barsbay Mayank M. Mehrota Mars Yentur Mark Rosenthal Dean Fuqua Y2 Justin Lloyd Hypernova Edmund Fokschaner Max Levine Matthew O’Connor Eugene Lawson Barry Hatfield Martha Hunt Joseph Salomone Chuck Zegar Craig Peterson Jordan Young Ratfeast John Hofmann Thanks to our Patreon Gamma Ray Burst Supporters: Denys Ivanov Nick Virtue Alexey Eromenko Nicholas Rose Scott Gossett Mark Dykstra Peter Durocher Michael Kers Chris Hicks Mark Vasile Patrick Murray Sultan Alkhulaifi Alex Seto Michal-Peanut Karmi Erik Stein Daniel Lyons Kevin Warne JJ Bagnell J Rejc Amy Jie Avi Goldfinger John Pettit Shannan Catalano Florian Stinglmayr Yubo Du Benoit Pagé-Guitard Nathan Leniz Jessica Fraley Loro Lukic Brandon Labonte David Crane Greg 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.

DO NOT TIP. This is an unofficial YouTube mirror of PBS Space Time (https://youtu.be/fG52mXN-uWI). If you want to tip PBS Space Time please visit https://www.patreon.com/pbsspacetime/. Convince PBS Space Time to join Odysee! ----------------------------- Viewers like you help make PBS (Thank you ?) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACE Unlock the secrets of Feynman Diagrams. Part 5 in our Quantum Field Theory series. And if you're submitting an answer to our challenge question email your answer by August 2nd to pbsspacetime [AT] gmail.com with the subject line "Feynman Diagram Challenge." You can further support us on Patreon at https://www.patreon.com/pbsspacetime Get your own Space Time t­shirt at http://bit.ly/1QlzoBi Tweet at us! @pbsspacetime Facebook: facebook.com/pbsspacetime Email us! pbsspacetime [at] gmail [dot] com Comment on Reddit: http://www.reddit.com/r/pbsspacetime Help translate our videos! https://www.youtube.com/timedtext_cs_... Previous Episode: The Real Star Wars https://www.youtube.com/watch?v=Q8shnjlGwmg Feynman’s path integral shows us that, to properly calculate the probability of a particle traveling from point A to point B, we need to add up the contributions from all conceivable paths between those points – including the impossible paths! In fact we can go even further: according to Feynman’s approach, every conceivable happening that leads from a measured initial state to a measured final state DOES in a sense happen. To calculate the probability of any quantum system evolving from one state into any other state we need to sum over every conceivable intermediate state. This is impossible because there are infinite possible intermediate states. Written and Hosted by Matt O’Dowd Produced by Rusty Ward Graphics by Kurt Ross Assistant Editing and Sound Design by Mike Petrow Made by Kornhaber Brown (www.kornhaberbrown.com) Comments answer by Matt: Superphilipp https://www.youtube.com/watch?v=Q8shnjlGwmg&lc=z13act14kwqcvv2nn22muvvztxqnjjryt04 Lewinham https://www.youtube.com/watch?v=Q8shnjlGwmg&lc=z12ajhwg3nubdnhaz04cfjfjumr2w5krek40k Myrmidon https://www.youtube.com/watch?v=Q8shnjlGwmg&lc=z12xupq5qqiqdbl4h04chd4x0syuxfnb1nk0k Sure people love Star Wars. But I think they missed a golden opportunity to call the project Ronald Ray-gun. Special thanks to our Patreon Big Bang, Quasar and Hypernova Supporters: Big Bang CoolAsCats Shane Robinson David Nicklas Eugene Lawson Joshua Davis Quasar Tambe Barsbay Max Levine Mayank M. Mehrota Mars Yentur Josh Mark Rosenthal Dean Fuqua Hypernova Chuck Zegar Jordan Young Ratfeast John Hofmann Joseph Salomone Martha Hunt Craig Peterson Science Via Markets Barry Hatfield Thanks to our Patreon Gamma Ray Burst Supporters: Peter Durocher Michael Kers Chris Hicks Mark Vasile Patrick Murray Justin Lloyd Sultan Alkhulaifi Alex Seto Conor Dillon Jared Moore Michal-Peanut Karmi Bernardo Higuera Erik Stein Daniel Lyons Kevin Warne JJ Bagnell J Rejc Amy Jie Avi Goldfinger John Pettit Shannan Catalano Florian Stinglmayr Yubo Du Benoit Pagé-Guitard Nathan Leniz Jessica Fraley Loro Lukic Brandon Labonte David Crane Greg Weiss