alt Hacker NewsThis is extremely strange. Shouldn't this be impossible by the second law of thermodynamics?
Receiving more energy when a resistor in thermal equilibrium is connected to an antenna seemingly implies that energy gets transferred from an antenna with a resistor to a an antenna without a resistor, even at thermal equilibrium.
Maybe we'll later find it's an experimental subtlety, like the faster than light neutrinos.
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dist-epoch • today at 12:59 PM
AI will explain it, but it's against HN rules for me to post the explanation.
Basically they are misleading when they say "thermal equilibrium", same physical temperature does not imply thermal equilibrium.
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cwmoore • today at 2:10 PM
Now consider the alignments of red blood cells.
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I'm not sure, as this paper is very confusing in its style, but I think they try to modulate the load resistance connected to an antenna on the TX side. Since the open has a large real resistance (25k in their case), it's poorly impedance matched to the antenna and most of the noise powwr cannot be transferred to the antenna at 1.4 GHz they are using. 50 ohm load is well matched, hence the max noise power transfer to the antenna. This is all at TX.
I don't see a thermodynamic problem here. Noise modulation with switching is well known in electronics. Switched resistors and their noise is already analyzed. It is often in the context of noise parr of SNR though. They are using this noise modulation to transmit signals, which isn't too novel. I guess the transmit power is very low but this would be horrible for Shannon spectral efficiency because of the need for noise power detection, which cannot be instantenous.