In other words, as an engineer I’ve spent many a time looking at the noise floor on a spectrum analyzer.
Unfiltered, unaveraged raw noise will bounce around a few decibels because that’s how it is....Gaussian. Stability only improves as the signal level rises higher above the noise.
It’s called signal-to-noise ratio (SNR); the higher the better and more stable. The article just says “in the middle of the pack” but never says what the real number is. I suspect with Christies numbers, he’s got a SNR of about 0dB, and that “middle of the pack” is the bottom half where they all are at about 1-2%.....
And kitchen physics applies as well. Just because a bowl of jello continues to shake after being jostled, it doesn’t mean it’s alive.