Energy balance after reflection of light - Help wanted

[mental_avenger]

What is the definition of reflection? (as used here) Studies with BEC do not address momentum, but they do address what happens to a photon. The BEC studies suggest that reflective materials do not “reflect†a photon, but rather absorb it and reemit it. Absorptive materials only absorb the photon. If a photon does not impart momentum to an object when it is emitted, then it is reasonable to conclude that it does not impart momentum to an object when it is absorbed.<br /><br />That seems to create a contradiction, if photons are “apparently†imparting a momentum to objects they impact. Is it possible that the momentum measured, in satellites for instance, is the result of the solar wind, not “light pressure� Also, is there evidence that photons impart momentum to objects from which they are emitted?<br /> <div class="Discussion_UserSignature"> <p style="margin-top:0in;margin-left:0in;margin-right:0in" class="MsoNormal"><font face="Times New Roman" size="2" color="#ff0000"><strong>Our Solar System must be passing through a Non Sequitur area of space.</strong></font></p> </div>

 

[h2ouniverse]

If that was solar wind (massed particles) and not radiation pressure, this would not correlate with optical reflectivity. Yet it does correlate. We have different behaviours depending on the fact that the surface is an MLI (highly reflective) or a Solar panel (highly absorptive).<br /><br />Besides, the effect is evidenced also on ground experiments.<br />

 

[jaxtraw]

I think you can think of it in terms of Newtonian colliisions. Momentum is conserved but depending on whether your ball bounces off the target or sticks to it, the target will end up with different momenta. An absorbtive surface is more like a sticky ball, a reflective one more like a um bouncy ball. So the final momenta of the targets will differ depending on their absorption/reflection.