/sci/ - Science & Math » Thread #14391420

4KiB, 259x194, download.png

View Same Google iqdb SauceNAO

Anonymous Wed 13 Apr 12:11:53 2022 No.14391420 View Reply Original Report

Quoted By: >>14391453 >>14393245 >>14393276 >>14395172 >>14395277 >>14395543

>light can propagate in a vacuum
>this is due to oscillating magnetic and electric fields in phase
>spin is what causes magnetic field
>direction of magnetic field flip flops in direction
Someone explain this. Does this mean the spin of a photon is sometimes negative? If not, how can the magnetic field change direction?

Anonymous

View Same Google iqdb SauceNAO 2530px-Cape_Cod_Air_Station_-_HA (...).jpg, 1MiB, 2530x2048

Anonymous Wed 13 Apr 2022 12:33:27 No.14391453 Report

Quoted By:

>>14391420

The polarization of a radiant EM field is basically the attraction of the positive and negative fields; in a linearly polarized field, they oscillate back and forth as the field travels, in accordance with the wavelength; and in a circularly polarized field, they orbit around each other as the field travels, in accordance with the wavelength.

Many modern radar systems use antenna arrays that can form multiple angles of linear polarization, to get useful information on contacts based on how the returns change (for example, a strong return up on a strait vertical pulse, but weaker return on other angles, would be a likely indication of rain on a weather radar, vs other kinds of precipitation).
Circular polarization is often used in space communications, as it is angle invariant and can be picked up at any orientation with an appropriate antenna.

Anonymous

Anonymous Wed 13 Apr 2022 12:45:52 No.14391475 Report

Quoted By: >>14394983

You're using the classical theory of EM propagation. In actuality, you must use QED.

Anonymous

Anonymous Wed 13 Apr 2022 23:38:58 No.14393245 Report

Quoted By:

>>14391420
>in a vacuum
Or
>this is due to oscillating magnetic and electric fields in phase
>spin is what causes magnetic field
>direction of magnetic field flip flops in direction

Not both.

Anonymous

Anonymous Thu 14 Apr 2022 00:00:02 No.14393276 Report

Quoted By: >>14394970 >>14394993

>>14391420
>Someone explain this
Sure, your understanding of electromagnetic fields is quite low. Spin is responsible for permanent magnets, which only emits a magnetic field. However when you push electrons through a medium, they will generate both an electric field and a magnetic field that are effectively 1:1 tied together. And as long as you have the quantum foam of space around, photons will interact with matter and each other should they collide.

And photons do have spin, but it has nothing to do with the propagation of fields but rather the direction or orientation of the field relative to you.

Anonymous

Anonymous Thu 14 Apr 2022 16:28:54 No.14394970 Report

Quoted By:

>>14393276
>Quantum foam
Discarded.

Anonymous

Anonymous Thu 14 Apr 2022 16:33:29 No.14394983 Report

Quoted By:

>>14391475
>i can't contribute meaningfully to this thread, but i can act pompous and pretend that i'm knowledgable in this topic by referencing jewish bullshit
>imma goooonnaa quantooooooommmm!!!

Anonymous

Anonymous Thu 14 Apr 2022 16:36:28 No.14394993 Report

Quoted By: >>14395538

>>14393276
So what caused the magnetic fields of photons?

Anonymous

Anonymous Thu 14 Apr 2022 17:43:22 No.14395172 Report

Quoted By:

>>14391420
Is it not that in total vacuum even a photon would go around it so no field could propagate in a total vacuum

Anonymous

Anonymous Thu 14 Apr 2022 18:16:49 No.14395277 Report

Quoted By:

>>14391420
>>spin is what causes magnetic field
No? Spin can interact with external magnetic fields, but it isn't what *causes* them. Your premise is false.
The photon, essentially, *is* the electromagnetic field. The fact that it carries spin is an additional, separate degree of freedom.
>Does this mean the spin of a photon is sometimes negative?
The photon is a spin-1 particle. It takes eigenvalues {-1, 0, 1} along an arbitrary spin axis. So, sure, it can be negative. This doesn't really mean anything profound.
>how can the magnetic field change direction?
It changes directions because that's what its equations of motion say. This is like asking how gravity causes a ball to roll down a hill.

Anonymous

Anonymous Thu 14 Apr 2022 20:15:58 No.14395538 Report

Quoted By:

>>14394993
Usually its a spinning permanent magnet pushing on copper electrons which are then amplified using capacitors and switching, and this amplified signal is pumped into an antenna which then outputs a certain shape of EMF depending on the wavelengths of the signal and the shape of the antenna itself.

Anonymous

Anonymous Thu 14 Apr 2022 20:17:51 No.14395543 Report

Quoted By:

>>14391420
>>this is due to oscillating magnetic and electric fields in phase
they arent in phase pseud

Capcode	All Only User Posts Only Moderator Posts Only Admin Posts Only Developer Posts
Show Posts	All Only With Images Only Without Images
Deleted Posts	All Only Deleted Posts Only Non-Deleted Posts
Ghost Posts	All Only Ghost Posts Only Non-Ghost Posts
Post Type	All Only Sticky Threads Only Opening Posts Only Reply Posts
Results	All Grouped By Threads
Order	Latest Posts First Oldest Posts First

Your latest searches