• Blue_Morpho@lemmy.world
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    6 months ago

    There aren’t infinite frequencies.

    “The mean free path in air is 68nm, and the mean inter-atomic spacing is some tens of nms about 30, while the speed of sound in air is 300 m/s, so that the absolute maximum frequency is about 5 Ghz.”

    • intensely_human@lemm.ee
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      6 months ago

      The term “mean free path” sounds a lot like an average to me, implying an distribution which extends beyond that number.

      • Blue_Morpho@lemmy.world
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        6 months ago

        One cubic centimeter of air contains 90,000,000,000,000 atoms. In that context, mean free path is 68nm up to the limits of your ability to measure. That is flip a coin 90 million million times and average the heads and tails. It’s going to be extremely close to 50%.

        Not to mention that at 5ghz, the sound can only propagate 68 nm.