Materials all have their own properties. Metals, for instance, have a melting point. They have conductivity, density, malleability, and ductility. Liquids, gases, and plasmas have properties as well. A material or an object can act differently at its interior, than at its edge. Consider some objects interacting with electromagnetic radiation.
Magnets and CapacitorsCapacitors exhibit so called Casimir edge effects. The electrical field between capacitor plates behaves differently at the edges, than between the centers. The same is true of the edges of magnets.
Frequency Skin EffectElectrical engineers understand the high frequency skin effect. The skin being the round outer layer or edges of the conductor. A copper wire conducts DC electricity throughout the wire. But AC electricity travels more along the outside of the wire, depending on the frequency.
The higher the frequency, the more the current moves away from the center. A practical working equation tells us about this. It says the skin depth of a conductor is inversely proportional to the square root of one over the frequency.
Universe Edge Effects?The universe is almost certainly finite. If it is finite, then in some way the universe might exhibit edge effects. In our discussion, we have considered electromagnetic field edge effects. Radiant energy is abundant in space. Could this be a source of edge effects? Are such effects displayed at the “ends” of the universe?
Could this add additional complexity to the questions, Where does light go? Why is the universe dark?
- Georgia State University – Hyperphysics: P-N Junction
- K&J Magnetics, Inc: Magnets are Weird
- Brilliant.org: Edge effects in the parallel plate capacitor
- Understanding Skin Effect and Frequency