Termyn8or
Posts: 18681
Joined: 11/12/2005 Status: offline
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Inverse square does apply to everything, but there is another factor, the loss factor. While it is not yet technically possible if one can generate a truly 100% coherent lase beam in a vacuum, inverse square has very little importance because the loss factor is infitesimal. However in the atmosphere it is quite a different story. Even a totally coherenyt laser beam would suffer so much loss, well, that is one of the problems in develping alot of new weapons, "star wars" for example. Propogation loss varies in the atmosphere with wavelength to a great degree. That is why some bands can be used for communication with geosynchonus satellites and others cannot. Some wavelengths make it through the ionosphere and others do not. It could with enough power, but the propogation loss brings inverse square in spades. Do not confuse this with dispersion, they are two different things. We recieve only so much of the sun's energy because of our distance and our size, that is area with which to absorb energy. The rest is indeed propogated, just not to us. This case is one in which inverse square is almost perfect. Progogation loss is nil, it is omnidirectional so our little eentsy slice of the universe on which it shines recieves it's little slice of that energy which happens to be the right amount to sustain life. So here we are. If you have a way to make waves non-divergent, in space, essentially a vacuum there is not loss. And if they diverge, yes, less is delivered, but one thing still holds. Energy has not been created nor destroyed. What wavelengths to use in the atmosphere need to be chosen carefully. Those that exhibit the least propogation loss should be used of course. Most bands are simply scattered too much. Even with the means to selectively focus it, the range would still be quite limited. When there is a propogation loss through a medium, that energy is still not destroyed. Some physical changes will be observable. But I am going to switch up now to the other aspect of this, and I wasn't even the one to bring this up. A weapon of this type used against a civilian population during an insurrection. Without getting too political, I do have one thing to say. The international community should demand that the US government dismantle any and all such weapons, abandon all research and any future plans to build more. Do you REALLY want the US govt to have this ? T
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