Tagged Questions
4
votes
1answer
102 views
What is the difference between Radiation and Electromagnetic Radiation
Are the two equivalent or is Electromagnetic Radiation a subset of Radiation. I am further confused by the fact that electromagnetic radiation includes both ionizing and non ionizing types of ...
0
votes
0answers
217 views
What is the correct definition of “group velocity dispersion”?
When we talk about a medium with dispersion, we can define the phase velocity $v_\phi = \omega/k$ and the group velocity $v_g = d\omega/dk$. Likewise the phase index $n = c/v_\phi$ and the group index ...
0
votes
0answers
195 views
Is Photosynthetic Photon Flux Density (PPFD) a synonym for Photosynthetically Active Radiation (PAR)?
Both have units of $\mu\text{mol m}^{-2}\text{s}^{-1}$ and refer to light in the 400-700 nm range - that activates photosynthesis. However, I just want to confirm that these are synonyms and don't ...
0
votes
0answers
112 views
What is the electric field part of an EM wave? Radiation field or the induction field?
Look at this image:
I wonder if the electric field is from the induction field from a vibrating electron or the radiation field? If it is from the radiation field, as I suppose, than can someone ...
