Have electromagnetic waves any polarity?

In summary, the conversation discusses the interaction between electromagnetic (EM) waves and electrons. The electric field of the EM wave interacts with the negative charge of the electron, causing it to be attracted or repulsed. This is seen in examples such as the microwaves oven, where the waves interact with water molecules. The polarization of the wave refers to the direction of the electric field's movement in a 2D plane. Electromagnetic waves do not require a medium to propagate, and other particles besides electrons, such as protons, can emit and interact with them. The quantum description of the Hydrogen atom involves the emission and absorption of photons by the proton and electron. These interactions can also occur through "virtual" photons. The
  • #1
live4physics
24
0
Hi,

My doubt is how can the EM waves interact with an electron, i.e.,
electron is a particle with negative charge.. have EM waves any charge to attract or to repulse an electron ? :confused:

An example is the microwaves oven when waves interact with water molecules.

Thanks :smile:
 
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  • #2
Remember, charges interact with each other via the electric field.
 
  • #3
very good... but the electric field (or magnetic) on EM waves has something like positive or negative signals?
 
  • #4
live4physics said:
very good... but the electric field (or magnetic) on EM waves has something like positive or negative signals?

The energy of the wave is measured in the 2D plane perpendicular to the direction of the field. There is 2 orthogonal dimensions and linear combinations of these. So the polarization of the wave is the direction (within this 2D plane) the field is moving in.

If you attach a string to an object and think of the string as the electric field, you can shake the string up and down or left and right or any linear combination of this. That is polarization.
 
  • #5
why electromagnetic waves doesnot require any medium to propagate
 
  • #6
emwv.gif


Only the electron particle can emit and interact with EM waves ?
 

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  • #7
live4physics said:
Only the electron particle can emit and interact with EM waves ?
protons by them selves can emit photons , as well as other particles .
And some particle anti-particle collisions .
 
  • #8
But can an EM wave emitted by the proton interact with electron ?
 
  • #9
it could interact through the gravitational force , I wonder how the magnetic field of the electron would permeate through a photon's localized energy , if it would be different than permeating through a vacuum .
 
  • #10
live4physics said:
But can an EM wave emitted by the proton interact with electron ?

Yes.
 
  • #11
live4physics said:
But can an EM wave emitted by the proton interact with electron ?
That's basically the Quantum Electrodynamics description of Hydrogen atom right there. Proton emits photons that are absorbed by electron, and vice versa.

Virtual off-the-shell photons, mostly, by the way.
 
  • #12
does a photon interact with electric and magnetic fields .
 

1. What is polarity in electromagnetic waves?

Polarity in electromagnetic waves refers to the direction of the electric field component of the wave. It can either be positive or negative, depending on the direction of the electric field.

2. Do all electromagnetic waves have polarity?

Yes, all electromagnetic waves have polarity. This is because they are made up of both an electric and magnetic field component, and the direction of the electric field determines the polarity of the wave.

3. How is polarity determined in electromagnetic waves?

Polarity in electromagnetic waves is determined by the direction of the electric field component of the wave. If the electric field is pointing in the same direction as the wave is traveling, the polarity is positive. If the electric field is pointing in the opposite direction, the polarity is negative.

4. Can polarity in electromagnetic waves be changed?

Yes, polarity in electromagnetic waves can be changed by altering the direction of the electric field component. This can be done by manipulating the wave's source or by passing it through certain materials that can change the direction of the electric field.

5. What is the significance of polarity in electromagnetic waves?

The polarity of electromagnetic waves is important because it determines how the wave interacts with matter. Waves with opposite polarities can cancel each other out, while waves with the same polarity can amplify each other. This plays a crucial role in various applications of electromagnetic waves, such as in communication and imaging technologies.

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