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Isn't linearly polarised light actually chiral when taking the magnetic field into account?

Just looking at the electric field is just 2D and therefore achiral, obviously.
But with the magnetic field included, the mirror image isn't the same right?
Everywhere I look it is written that linearly polarised light is achiral, I'm assuming because usually the magnetic field is disregarded.

Jorge
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    You should think of the magnetic field not as a vector but rather as a bivector, a surface "thing". For a linear polarized wave the electric field vector and the direction of the ray (Poynting vector) forms a plane, the magnetic field as bivector is in that plane not as a vector but rather as "whirl"., see https://physics.stackexchange.com/questions/410714/why-does-a-magnetic-field-curl-around-a-current-carrying-element/410735#410735 and https://physics.stackexchange.com/questions/160993/why-does-a-magnetic-field-go-anticlockwise-of-the-direction-of-current/161036#161036; no mirror worry now. – hyportnex Feb 08 '24 at 14:51
  • Thank you! I don't understand this :( – Jorge Feb 08 '24 at 15:21
  • to get a better feeling you should remember that the electric field is associated with a path integral representing work along it. The relevant part of the projection of the E- field on the tangent line to the path. The magnetic B-field is associated with flux through a surface, it is a surface thing, and on that surface it can whirl clock-wise or counter-clockwise in analogy to a vector that can point along a line "up" or "down". A surface "thing" such as a B-field can be represented by a pair of vectors similarly to a volume "thing" that would need three vectors. – hyportnex Feb 08 '24 at 15:31
  • Now think of what happens to CW and CCW in a mirror. – hyportnex Feb 08 '24 at 15:32
  • WP and also. – Cosmas Zachos Feb 08 '24 at 15:53
  • Thanks, I'm not sure it answers my question. But it's definitely something I didn't consider! – Jorge Feb 10 '24 at 10:37
  • For laser light, all the light would be left or right handed ... not both. One day you turn your laser on it is right handed, next day maybe its left handed, .... but scientists don't have ability today to determine it. – PhysicsDave Feb 11 '24 at 14:46
  • @hyportnex Thank you very much! I pondered this and think I understand this now!! I'm wondering though: If we have a magnetic or an electric field or both depends on the reference frame (Faraday tensor), e.g. electrons moving in a wire and a proton moving with the same speed along the wire. Moving charges create magnetic field and that is where the interaction takes place. ... – Jorge Feb 28 '24 at 17:10
  • @hyportnex ... Whereas from the point of view of the moving proton, the electrons are at rest, but the protons in the wire are moving (appear contracted leading to a net charge, resulting in an electric field). The interaction is via the electric field then. You are saying the magnetic vector is a "whirl" (pseudovector). This makes sense to me. In a different reference frame however: Would the electric vector be a "whirl" (pseudovector)? Thank you very much for your time! – Jorge Feb 28 '24 at 17:10
  • The Lorentz transformation of the EM field mixes the E and H components in one frame to another set but the nature of the E and H fields do not change in the sense that an electric dipole is responsive to the E components while a magnetic dipole to the H components, be it in the old or in the new frame. This is manifest in the Faraday tensor that has the same structure in any inertial frame, see. – hyportnex Feb 28 '24 at 17:39

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The photons of electromagnetic radiation are chiral. And the reason is exactly the one you cite and which is also mentioned in the name - "electromagnetic" radiation. What's more, the photons of electrons all have the same arrangement of electric and magnetic field components. This is easy to prove.

In a radio wave, the electrons are moved back and forth on the antenna rod, emitting vast quantities of polarised photons. Their electric fields are sometimes orientated upwards (for a vertical rod, of course) and sometimes downwards every half period. At the same time, the magnetic fields of the photons are sometimes orientated to the left and sometimes to the right. If this were not the case, we would not be able to build a magnetic antenna as a receiver.

Addition
The electric and magnetic field components of an antenna are emitted perpendicular to each other. The two sketches show the near field of the antenna, in which the two components oscillate offset by 90° in the direction of radiation. It can be seen from the sketches that the position of the two fields can be readjusted according to the right-hand or left-hand rule (which also determines the chirality). Nature has - fortunately - decided that the electrons only emit photons according to the right-hand rule. Otherwise the generation of electricity and radio transmissions would be impossible. Lorentz force and Hall effects would also be impossible.

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HolgerFiedler
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