In Feynman's lectures he describes partial reflection as occuring because the "little arrows" cancel out when the glass is certain thickness. I realize that there isn't an actual model of how QED works but what exactly does he mean by "cancel out"?(adsbygoogle = window.adsbygoogle || []).push({});

Also when do you shrink and turn the little arrows and when do you "add" them together, head to tail? Do you shrink and turn arrows until you get a final arrow and then proceed to "add" several final arrows together? If so, does that mean that shrink and turning arrows gets you one step(i.e. whether a photon is reflected or transmitted) in an event(i.e. whether a photon will pass through a pane of glass)?

Thanks for the help. And FYI, I'll more than likely be back with more questions as I read more :).

EDIT:4 minutes after my original post and I already have another question lol. Feynman states that an electron "orbits" a proton in a hydrogen atom because the two are continuously exchanging photons. In his diagram, however, I can't find any path of a photon that would "push" the electron towards the proton. All of his pathes seem like they should "push" the electron away, not toward, the proton. I have a sneeking suspicion that this has something to do with positrons traveling backward in time but I'm not sure. Once again,thanks for the help.

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Feynman's QED Lectures: Questions about partial reflection

Loading...

Similar Threads - Feynman's Lectures Questions | Date |
---|---|

I A few questions about Feynman's QED Lecture | Feb 4, 2017 |

I Feynman Lectures: negative alpha for solving Schrödinger equation | Jul 16, 2016 |

B Double Slit Experiment: Feynman's Lectures | May 29, 2016 |

I Feynman Lecture Vol III Ch. 8 Question -- Heisenberg matrix picture | Apr 10, 2016 |

Is this statement about the Uncertainty Principle correct? | Jul 29, 2015 |

**Physics Forums - The Fusion of Science and Community**