The Biggest Ideas in the Universe | 10. Interactions

The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that help us understand our natural world. Exceedingly casual, not overly polished, and meant for absolutely everybody.

This is Idea #10, "Interactions." Last time we dipped a toe into quantum field theory, seeing how quantizing fields leads to particles. Now we let the particles interact with each other, and see how the results are characterized by Feynman diagrams.

#science #physics #ideas #universe #learning #cosmology #philosophy #quantum #fields #feynman

[vinm]

This series will be the best thing on YouTube for decades.

[chiphill]

Thanks for hitting the technical complexity sweet spot. These are great videos!

[werneryc]

Great series you made here. I love how you take care of the details but still stay sufficiently on the surface

[esperancaemisterio]

Stopping everything to watch the new video! =)

[nathanisbored]

i think the reason you keep 'slipping' and calling these lectures is because you secretly want historians to refer to these videos as the Carroll Lectures

[TetonGemWorks]

These are great videos, but I'm failing this class....
Won't stop watching and rewatching. Just love listening to the Professor explain thing, go on tangents, the whole thing.

[ulob]

Neat spherical-cyberpunk cow in the background!

[archaicentity]

I think it was John Wheeler who gave Feynman the idea that the positron is an electron moving backwards in time.

[beagle]

Great series! Are you going to do a "Lenny" and write a Theoretical Minimum based on this series? That would be great and something good would come out of lockdown.

[rodrigoserafim]

49:20 "an electron, a positron and a photon..." walk into a bar. electron turns to the positron and says 'i'm feeling negative', positron asks responds 'are you positive?', photon interjects 'can you guys see where this is going?'

[Saitama]

Would an Eternalist look at a Feynmann diagram as not going from right to left or left to right, but just *being there*?

[johnrendle]

Such a pleasure to watch your lectures….I’m a radiologist and you’ve given me a Eureka moment re PET and the fact that you get two photos rather than one in positron-electron interactions. Thank you!

[qrQRbMBGhjGpZhnWqG]

Such an amazing physicist and communicator. Such a terrible arrow head drawer. 23:15 :D

[MichalCanecky]

I'm the spherical cow everyone is talking about.

[shaunkrueger]

I wonder what sort of person clicks on a theoretical physicist's lecture during a pandemic and gives it a thumbs down. Must have been an anti-Everettian.

[NGC-]

Sean: There is only one diagram we can draw for this
Sean 5 minutes later: There is an infinite amount of diagrams we can draw for this

[paulc]

Reminder : at 41:00 This video, (no. 10 - Interactions) is where the "Lagrangian" & "Lagrange Density" is discussed & explained. Fully.

[michaeljmorrison]

Enjoying your lectures....we are so lucky that corona seems to have you with us -a very real silver lining! So.... my question....Is gravity emergent and if so can it be manipulated by affecting entropy in a particular volume of space or even specifically here on Earth?

[ticket]

"The Biggest Ideas in the Universe" series is fantastic! They are timeless content. This format of explaining one concept is great.

[hot-sawse]

i think one future problem may be that there is no small metric for the density or energy level, if i had to guess id say those measurements are based on the individual doing the measurement, . once again thank you. great informational video*