Quantum socks

Collins, D, Diosi, L, Gisin, N +2 more

Ahmad Darwish, Matteo Murdaca, Jami J. Kinnunen

It is a universal empirical observation that socks become unpaired in the laundry. We propose a quasiparticle theory of sock dynamics in which individual socks are modelled as bosonic excitations of the agitated laundry condensate. The sock dispersion relation is material-dependent: nondispersive materials retain their shape, while dispersive materials give rise to the well-documented phenomenon of sock shrinkage. In the convex regions of the dispersive spectrum, socks undergo Beliaev decay and spontaneously split into two lower-momentum socks, while in the concave regions the dominant process is Landau-Khalatnikov scattering, which degrades socks into lint and loose threads. In addition, the rotating drum creates sock-antisock pairs from the laundry vacuum via the dynamical Casimir effect. The coexistence of these creation and destruction channels gives rise to a fundamental ambiguity: an unpaired sock at the end of a wash cycle is equally consistent with the destruction of its partner or the spontaneous creation of an entirely new sock.

James S. Bell

Introduction The philosopher in the street, who has not suffered a course in quantum mechanics, is quite unimpressed by Einstein–Podolsky–Rosen correlations. He can point to many examples of similar correlations in everyday life. The case of Bertlmann's socks is often cited. Dr. Bertlmann likes to wear two socks of different colours. Which colour he will have on a given foot on a given day is quite unpredictable. But when you see (Fig. 1) that the first sock is pink you can be already sure that the second sock will not be pink. Observation of the first, and experience of Bertlmann, gives immediate information about the second. There is no accounting for tastes, but apart from that there is no mystery here. And is not the EPR business just the same? Consider for example the particular EPR gedanken experiment of Bohm (Fig. 2). Two suitable particles, suitably prepared (in the ‘singlet spin state’), are directed from a common source towards two widely separated magnets followed by detecting screens. Each time the experiment is performed each of the two particles is deflected either up or down at the corresponding magnet. Whether either particle separately goes up or down on a given occasion is quite unpredictable. But when one particle goes up the other always goes down and vice-versa. After a little experience it is enough to look at one side to know also about the other.

Kien Lam

Alexander Afriat

ABSTRACT: It is argued that perfect quantum correlations cannot be due to additive conservation. Dr. Bertlmann likes to wear two socks of different colours. Which colour he will have on a given foot on a given day is quite unpredictable. But when you see that the first sock is pink you can already be sure that the second sock will not be pink. Observation of the first, and experience of Bertlmann, gives immediate information about the second. Bell (1981) Most interesting features of quantum mechanics have at least something to do with interference, which will not, however, be at issue here at all. Interference is brought out by an appeal to different bases, but here the same (product) basis is adhered to throughout. It is often claimed, and even more often suspected, that conservation accounts for quantum correlations (by which perfect quantum correlations will be meant). The underlying intuition is well expressed by Bertlmann’s socks, or by the fact that the distribution of wine over two glasses can be worked out, provided one knows the total amount in both, by a measurement on one of them. Or consider a conservative classical Hamiltonian where T is kinetic energy and the potential energy V depends only on position. Conservation here means that exchanges of kinetic and potential energy along a trajectory have to satisfy where is the total energy of that motion. Kinetic energy will then be a function only of position, so that at any stage of the motion can be deduced from the potential; they are perfectly correlated. Or take two free classical particles, each one subject only to the influence of the other, with initial momenta and Irrespective of whether they collide their total momentum will remain the momentum of the primed particle can always be derived from the momentum p of the other. These cases are paradigmatic for additive conservation. (),H T V q = +