Re permittivity of vacuum, etc, the ephemeral particle pairs “explanation” is the Dirac sea hypothesis right? Iirc that fell out of favor and now it’s usually explained purely in terms of the uncertainty principle?
At the risk of being out of my depth here, the Dirac sea hypothesis is what led to the concept of positrons. I'm not really sure if that was used to explain the permittivity of free space. From what I can tell, the Quantum Field Theory (which replaced the Dirac Sea) attributes the polarizability of a vacuum to quantum fluctuations arising from matter-antimatter annihilations of some complex sort. Thats why we can assign permittivity to free space (or something like that) :) I really should have done more physics courses, and skipped learnable EE stuff.
Meta materials found a lot of application in planar antennas specifically designing circular polarised antenna due application in GNSS bands. They are an alternative to aperture coupled antennas used in space communication.
A very unique one. I have never thought about negative permeability and permittivity. The moment I saw the wave propagation is reversed, I had a random thought if using metamaterial, can we somehow make time travel possible(Probably not related, but a thought I got in my mind, when I first read this).
Re permittivity of vacuum, etc, the ephemeral particle pairs “explanation” is the Dirac sea hypothesis right? Iirc that fell out of favor and now it’s usually explained purely in terms of the uncertainty principle?
At the risk of being out of my depth here, the Dirac sea hypothesis is what led to the concept of positrons. I'm not really sure if that was used to explain the permittivity of free space. From what I can tell, the Quantum Field Theory (which replaced the Dirac Sea) attributes the polarizability of a vacuum to quantum fluctuations arising from matter-antimatter annihilations of some complex sort. Thats why we can assign permittivity to free space (or something like that) :) I really should have done more physics courses, and skipped learnable EE stuff.
Ah blind leading the blind here. I guess we should both back away carefully like Homer Simpson into the hedge.
😝
Insightful topic viks.
Meta materials found a lot of application in planar antennas specifically designing circular polarised antenna due application in GNSS bands. They are an alternative to aperture coupled antennas used in space communication.
nice write up, Vikram. Hope to see more content on this topic.
What a fun read! Livened up my otherwise sleepy Sunday. 🙂
A very unique one. I have never thought about negative permeability and permittivity. The moment I saw the wave propagation is reversed, I had a random thought if using metamaterial, can we somehow make time travel possible(Probably not related, but a thought I got in my mind, when I first read this).