Hacker News Reader

The effect is apparently small enough that they had to use Fourier analysis over many minutes to see it in the noise.

That's not really telling us anything. The way you convert a time domain signal to a frequency domain signal, that is fourier analysis. There are other uses for it too, but that is the primary use.

By increasing the length of the FFT you lower the apparent noise floor in the FFT magnitude plot and are able to detect smaller signals. That's called "FFT processing gain". The formula is:

FFT gain = 10*log(M/2)

where M is the number of points processed in the FFT. Doubling the number of points, lowers the apparent noise floor by 3 dB.

(I don't know if that's what the researchers actually did. I'm just explaining what the comment presumably meant.)

That's what they did. See [1], Fig. 3. (Which, amazingly for Nature, has a free download of the PDF.) This isn't something that shows up in a plain load vs time graph.

[1] https://www.nature.com/articles/s41560-026-02144-0

Reply on news.ycombinator.com