1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

QED, partial reflection, Feynman, FTL

  1. Nov 5, 2012 #1
    I would like to discuss partial reflection of the photons and how thickness of the material (let's say glass) affects reflection (originally from Feynman, QED).
    Let's say we have a glass 1m apart from the detector, and another glass 100m apart. The thickness of second glass affects probability waves and the percentage of the light reflected. I find this paradoxical. Let's say we shoot some photons to the glass. It takes 1m/c + 1m/c time to detect reflection from the first glass (highest probability wave peak).
    My question is, how after 2m/c time we can know if there is another glass 100m apart? That's kinda FTL.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted