10 Points!!!!?

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It's because the time varying E and H fields of the incident EM wave induce currents at the surface of the conductor which (in accordance with Lenz's law and Maxwells equations) are in opposition to those in the incident wave. Note too that only the E field maintains its relative phase, the H field is 'flipped' by π rad so the Poynting vector (P = EXH) is also reversed and the resulting wave front moves in the direction opposit that of the incident wave. (That's for an incident wave normal to the reflecting surface) If it's off normal then you have to go thru a bunch of stuff involving Huygens Principle as it applies to 3-D vector calculus to see that the reflected angle (WRT the normal) is the same as the incident angle (looking thru the plane formed by the normal and the incident wave)

The math is straightforward, albeit a bit tedious and messy in places.

As an aside...... Isn't is amost spooky the number of people hanging out in Physics Q&A who don't have a clue about Physics? And hell, I'm just a mathematician.

Doug

**** Yo, Dennis_d_wurm!!

You ought to hang out in the math Q&A <g>
Somebody over there said they couldn't remember if 3 times 3 was 33 or 9 (I'm not making it up <g>)...Show more

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Zero point energy has been called "the ultimate quantum free lunch" (Science, Vol. 275, 1/10/97). During the early years of quantum mechanics, Paul Dirac theorized that the vacuum was actually filled with particles in negative energy states (Proc. R. Soc. London A, 126, 360, 1930) thus giving rise to the concept of the "physical vacuum" which is not empty at all. Quantum mechanics also predicted that invisible particles could become materialized for a short time and that these virtual particle appearances should exert a force that is measurable. Hendrik B. G. Casimir (Phys. Rev. 73, 360, 1948) not only predicted the presence of such a force but also explained why van der Waals forces dropped off unexpectedly at long range separation between atoms, predicting that force F=K/d4 where K=p hc/480. Though the Casimir effect subsequently was verified using non-conductive plates, there was always a scientific need for a verification of the Casimir force using conductive plates based on Casimir's 1948 paper. For the first time, Dr. Lamoreaux, now at the Los Alamos Labs, performed the experiment with less than one micrometer (micron) spacing between gold-plated parallel plates attached to a torsion pendulum (Phys. Rev. Ltrs., 78, 1, 97). In retrospect, he found it to one of the most intellectually satisfying experiments that he ever performed since the results matched the theory so closely (within 5%).

The Casimir effect has been posited as a force produced solely by activity in the vacuum. The Casimir force is also very powerful at small distances. Besides being independent of temperature, it is inversely proportional to the fourth power of the distance between the plates! Therefore, as the plates are brought closer, the virtual particles outside the plates increasingly overpower the decreasing quantity of virtual particles appearing between the plates with an exponentially increasing force. (Also notable is the fact that its frequency dependence is a third power and the force can be altered with dielectrics or resonate with narrow-band mirrors-see Phys. Lett. A 225, 1997, 188-194.) Lamoreaux's results come as no surprise to anyone familiar with quantum electrodynamics (QED), but they serve as a material confirmation of an unusual theoretical prediction that QED predicts the all-pervading vacuum continuously spawns particles and waves that spontaneously pop in and out of existence. Their time of existence is strictly limited by the uncertainty principle but they create some havoc while they bounce around during their brief lifespan. The churning quantum foam extends throughout the universe even filling the empty space within the atoms. A diagram showing "The Shape of Nothing" (The New York Times, 1/21/97) is pictured to be not only subatomic but subelementary particle in size. Physical theories predict that on an infinitesimally small scale, far, far smaller than the diameter of atomic nucleus, quantum fluctuations produce a foam of erupting and collapsing, virtual particles, visualized as a topographic distortion of the fabric of space time....Show more

A conductor is the best reflector for energy because it does not store any of that energy. So you get the same amount of energy coming off that conductor all the time....Show more

electromagnetic energy is just that, electric. meaning conductors, which are able to channel electricity, have the capacity to exhibit electromagnetism.

what this says about your question is that, no other kind of material can exhibit electromagnetism other than conductors. therefore, only conductors CAN reflect electromagnetic energy, coz other kinds of materials will just cancel the thing out....Show more