10 Points!!!!?

Question

I have nothing else to do... The 1st correct answer gets the points!!!

Why are conductors the best reflectors of electromagnetic energy in general?

I am looking for an explanation that involves the properties of a material that make it a conductor, and the electromagnetic properties of EM waves.

I know the answer, BTW.

So far, doug_donaghue has the best answer...

And doug, I agree with what you said at the end... For sure it makes me smile and laugh...

Answer 1

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
Somebody over there said they couldn't remember if 3 times 3 was 33 or 9 (I'm not making it up )

Answer 2

2

Answer 3

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.

Answer 4

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.

Answer 5

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.

Answer 6

I will say because conductors have lots of free electrons so that when the electromagnetic signal comes close it is repelled by the free electrons of the conductor which give reflection of the signal

Answer 7

because they dont reflect the energy they absorb it


ops sry conductors dont reflect energy the conduct it


cinnamonscen... 5 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide


puertorican_... 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide


johnbntexas 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide


im going to guess because they naturally reflect


JT R 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide



offcourse...

they condcut well and reflect more..to be conductive, relxise shold be good



snowy 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide



Something that allows electricity to flow through it easily. Water and most metals are good conductors. Conductors can allow electricity to flow through them because the electrons in their atoms move between atoms very easily.



turkey pizza... 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide


ssgtusmc3013 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide


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.


Dr. L 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide



ill take the two haha. because they conduct? ahahha


sugar4sandy 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide



because conductors reflect electromagnetic energy best.

Jeanine G 4 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide
Because at the atomic level, reflection is actually an induced current and currents can be induced in conductors better.
rscanner 3 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating:

science is stupid ughh skools coming and yuck i have

bsktballchik 3 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide

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.
meow_955 3 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide

I have nothing else to do... can i have at least 2 points. yipee it's all about the points. Thank you for 2 points although I would appreciate you changing you mind and giving me 12 points. can you please?

diane 2 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide

The resistance to flow of an electric current through a material depends on the mobility of electrons in the material. In conductors (e.g. metals) the electrons flow easily, while in insulators (e.g., wood, glasses) they flow hardly at all. The resistance to flow converts electric energy to heat energ
rottie110 2 minutes ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide

the electrons gain energy and in a metallic lattice, the electrons can flow easily. tungsten , like every solid, has a melting point and before the material reaches the m.p it emits a large amount of light since the elctrons gain energy and can escape the positive charge the holds them.


Hani G 1 minute ago You gave this answer a low rating: Show
You gave this answer a low rating: Hide

doens't matter i still get 2points

Answer 8

The resistance to flow of an electric current through a material depends on the mobility of electrons in the material. In conductors (e.g. metals) the electrons flow easily, while in insulators (e.g., wood, glasses) they flow hardly at all. The resistance to flow converts electric energy to heat energy.

Answer 9

the electrons gain energy and in a metallic lattice, the electrons can flow easily. tungsten , like every solid, has a melting point and before the material reaches the m.p it emits a large amount of light since the elctrons gain energy and can escape the positive charge the holds them.

Answer 10

Because at the atomic level, reflection is actually an induced current and currents can be induced in conductors better.