Why are electromagnetic waves transverse waves? Is this answer ok?

In summary: Since there was no medium which could support transverse waves, it was concluded that light cannot be a transverse wave and therefore the aether theory was flawed. However, when Maxwell's equations came along, they showed that light can be explained as transverse electromagnetic waves, without the need for an aether. This is because an electric field can induce a magnetic field and vice versa, allowing for the propagation of transverse waves through empty space. In summary, electromagnetic waves are transverse because they are generated by the rapid vibration of electrons, which move perpendicular to the direction of wave travel. This can be explained by Maxwell's equations, which show that transverse waves can be propagated through empty space without the need for a medium.
  • #1
Spinnor
Gold Member
2,214
424
From: http://answers.yahoo.com/question/index?qid=20090223155307AAgqbWk

Question: Why are electromagnetic waves transverse waves?

Answer: "Because they are generated by the rapid vibration of elecrons, which go side to side, perpendicular to the direction the waves travel (very very rapid vibration, mind you)"

How might you improve this answer?

Thanks for any help!
 
Physics news on Phys.org
  • #2
EM waves are transverse waves because they can be polarized.
 
  • #3
You can use Maxwell's equations to show that a plane wave in free space is transverse. Imagine a plane wave traveling in the x direction, E(x,t).

Gauss' law states [itex]\frac{\partial E_{x}}{\partial x}=0[/itex] since there is no field variation in the y,z directions.
Ampere's law states [itex]\mu_{0}\epsilon_{0}\frac{\partial E_x}{\partial t}=\frac{\partial B_z}{\partial y}-\frac{\partial B_y}{\partial z}=0[/itex] for the same reason.

So the component of E in the direction of propagation does not vary in space or time, ie the wave is transverse.

Since you can represent a solution to the wave equation by a sum of plane waves, this is enough to show that EM waves are transverse in isotropic, homogeneous media.
 
  • #4
Hi, Spinnor

We observe transverse components as electromagnetic waves.
Longitudinal component is observed as static field.

I am not so confident in my answer. Correction from you is fully appreciated.

Regards.
 
Last edited:
  • #5
Back in the days when scientists believed in a frictionless aether fluid in order to explain propagation of light through space, one of the arguments against the existence of aether was the fact that transverse waves can only be propagated though a solid medium.
 

1. Why are electromagnetic waves transverse waves?

Electromagnetic waves are transverse waves because the oscillations of electric and magnetic fields that make up the wave occur perpendicular to the direction of propagation. This means that the electric and magnetic fields are perpendicular to each other and to the direction in which the wave is traveling.

2. How do we know that electromagnetic waves are transverse waves?

Scientists have conducted experiments and observations that show that electromagnetic waves exhibit all the characteristics of transverse waves. These include the ability to polarize, undergo interference and diffraction, and exhibit wave-like behavior.

3. Can electromagnetic waves also be longitudinal waves?

No, electromagnetic waves cannot be longitudinal waves. Longitudinal waves require the oscillations to be parallel to the direction of propagation, which is not the case for electromagnetic waves. Therefore, they can only be transverse waves.

4. What is the significance of electromagnetic waves being transverse?

The transverse nature of electromagnetic waves allows them to propagate through vacuum. This means that they do not require a medium to travel through, making them ideal for communication and other applications. Additionally, their transverse nature allows for the manipulation and control of the direction and polarization of the wave.

5. Is this answer sufficient to explain why electromagnetic waves are transverse?

This answer provides a basic understanding of why electromagnetic waves are transverse. However, for a more in-depth explanation, one could also mention the mathematical representation of transverse waves using Maxwell's equations and the Lorentz force law.

Similar threads

  • Electromagnetism
Replies
4
Views
851
  • Electromagnetism
Replies
17
Views
3K
Replies
5
Views
785
Replies
1
Views
447
Replies
8
Views
964
  • Electromagnetism
Replies
15
Views
1K
Replies
9
Views
2K
  • Electromagnetism
Replies
8
Views
1K
  • Electromagnetism
Replies
5
Views
3K
  • Electromagnetism
Replies
8
Views
2K
Back
Top