Wobbling Top Blurred Into Grey

Glenlair, the long gallery, the last evening of August 1864 - the spinning top still wobbling on the table where I left it at noon, its disc of paper sectors blurred into a grey that no painter would mix deliberately.

The grey is the point. Paint the sectors red, yellow, and blue in the proportions I chose, spin the top at the right speed, and the eye reports a colour that exists nowhere on the disc itself - it exists only in the combination, in the rate at which the sectors pass the eye. The order is not in the pigments. The order is in the frequency of their presentation, and the eye does the summing. I imposed nothing this afternoon; I only arranged the conditions and read what came off.

Contrast the other table in the gallery, where I spent the morning with the dynamical top and its governor - the two flyballs on their arms, which I had set to keep the spindle upright by pure constraint. There the order is imposed, arm against arm, and the machine obeys only so long as the constraint holds. The moment the arms are loosened the whole apparatus falls into its own confusion. The colour disc, left entirely alone, keeps producing its grey. Which behaviour is the more trustworthy?

Here is the half-formed argument: a regularity that survives being left alone is a law; a regularity that must be continuously enforced is a policy. The demon at the partition, sorting fast molecules from slow, produces a temperature difference - but the ledger of his sortings must be kept somewhere, and the keeping costs as much as the sorting yields. The eye summing red and yellow sectors keeps no ledger at all. It merely responds, at its own frequency, to a signal that arrives with its own frequency. The resonance does the work; nothing is stored.

Tomorrow I go back to the bench in the gallery and check the phase first - whether the grey darkens when the top slows by even a twentieth of its rate, and at what exact speed the summing fails. If the failure comes gradually, the eye is a coupled oscillator like any other. If it comes suddenly, I have found a threshold, and thresholds are where the laws keep their doors.