How to insulate an object with electromagnetism?

  • Context: Undergrad 
  • Thread starter Thread starter Atran
  • Start date Start date
  • Tags Tags
    Electromagnetism
Click For Summary

Discussion Overview

The discussion revolves around the concept of using electromagnetic waves for insulation, particularly focusing on the feasibility of shielding an object from various wavelengths of electromagnetic radiation, including radio waves and x-rays. Participants explore theoretical scenarios and practical implications of wave interactions and shielding materials.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that waves with longer wavelengths are easier to shield against due to their inability to penetrate small openings in shielding materials.
  • It is noted that waves do not travel uniformly and can be affected by reflections and refractions from objects in their path.
  • One participant questions the concept of insulating an object against waves of different wavelengths, seeking clarification on the nature of such insulation.
  • Another participant asserts that it is not possible to shield an object from specific wavelengths using waves of another wavelength, citing the principle of superposition.
  • Some participants suggest that a physical conductive barrier, such as a Faraday cage, can effectively block electromagnetic waves across a range of frequencies.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of using electromagnetic waves for insulation, with some asserting that specific wavelengths cannot shield against others, while others explore the theoretical implications of such shielding. The discussion remains unresolved with multiple competing views present.

Contextual Notes

Participants highlight limitations in understanding the interactions of different wavelengths and the conditions under which shielding might be effective. There is also a lack of consensus on the practicality of using waves for insulation versus physical barriers.

Atran
Messages
93
Reaction score
1
Hi. I've got two questions.

Is it true that waves with longer wavelengths are handled easier?

Think of a scenario where radio-waves insulate a solid object (in a lab for example). How can this be done? Given my understanding, waves don't travel around the environment uniformly.
 
  • Like
Likes   Reactions: Delta2
Physics news on Phys.org
yes well, it is easier to shield objects from waves with longer wavelengths because such waves can't penetrate through small openings and imperfections of the shielding material. As a rule of thump a wave can't penetrate and will be mostly reflected by an opening if the opening dimensions are smaller than 1/10 of its wavelength.

Waves don't travel uniformly indeed because they get reflected/refracted/e.tc from the various objects they hit in their way, and also the antennas that emit those waves are not perfect isotropic radiators, that is they don't emit the same amount of energy spherically in all directions, some directions are favored. For example a center fed dipole antenna emits much more energy in the direction perpendicular to the axis of the dipole, than the direction parallel to the axis of the dipole.
 
Atran said:
Think of a scenario where radio-waves insulate a solid object

Insulate against what?
 
  • Like
Likes   Reactions: russ_watters
Vanadium 50 said:
Insulate against what?

Against waves of other wavelengths. Imagine an object surrounded by a "sphere" of waves of a certain wavelength, that shields the object from waves of other wavelength.

Am I correct in saying that x-rays can penetrate radio-waves while the reverse is not true?
 
  • Skeptical
Likes   Reactions: Delta2
You need a proper material to shield an object from incoming waves, you can't shield it from waves of specific wavelength using waves of another wavelength. When two waves of different wavelength meet in space the result is a wave that is an addition of the two waves (principle of superposition).
 
Atran said:
Imagine an object surrounded by a "sphere" of waves of a certain wavelength, that shields the object from waves of other wavelength.

Not possible. Electromagnetic waves are linear.
 
  • Like
Likes   Reactions: jbriggs444
what you can do is put a physical conductive sphere around whatever you want to protect and no EM will get through , if you want to block all frequencies starting from the very low up to ionizing radiation you can just make your sphere very thick and job done.

for radio wave blocking such spheres and meshes are called "Faraday cage".
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 36 ·
2
Replies
36
Views
6K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
21K
  • · Replies 4 ·
Replies
4
Views
3K