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