What does this equation mean?

Reading a decoherence time off this table only requires the exponent above: a superposition separated by $\Delta$ x decays with a characteristic time t $\sim$ 1/($\Lambda$\, $\Delta$ $x^2$) . Take the largest grain delocalized over roughly its own diameter, $\Delta$ x $\approx$ 10^{-3} centimetres, and the numbers in the first column turn into times measured in seconds only in the single, almost pathologically clean case of the cosmic background radiation acting alone — about one second. Every other row is not a slower version of the same story; it is a different order of magnitude of story entirely. Ordinary air brings that same superposition down to roughly 10^{-30} seconds, and a superposition delocalized over a full centimetre — genuinely macroscopically distinct positions — decoheres in air in roughly 10^{-36} seconds, a span of time with no operational meaning at all next to any timescale on which a physicist, or a chair, does anything. Even Joos and Zeh’s own “large molecule” column, sized for something in the mass range of a C60 cage rather than a visible speck of dust, still shows scattering off ordinary air overwhelming scattering off the cosmic background by thirty orders of magnitude — which is exactly why the 1999 and 2019 interferometry results opening this article had to be run in high vacuum, on a molecular beam, and nowhere near open air [ 7 ] [ 9 ] [ 10 ] . Joos and Zeh’s own language for this asymmetry is understated: an equilibrated environment such as thermal radiation “is able to destroy (or dislocalize) interference terms,” and the mechanism at work is “the sensitivity of macroscopic systems upon their environment” [ 7 ] . The arithmetic is what makes that sentence load-bearing rather than merely qualitative.