The Secrets of Feynman Diagrams

Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: 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] with the subject line “Feynman Diagram Challenge.“ You can further support us on Patreon at Get your own Space Time t­shirt at Tweet at us! @pbsspacetime Facebook: Email us! pbsspacetime [at] gmail [dot] com Comment on Reddit: Help translate our videos! Previous Episode: The Real Star Wars 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 () Comments answer by Matt: Superphilipp Lewinham Myrmidon 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