Mining quantum stuff

Brian Hayes

Randomness is not something we usually look upon as a vital natural resource, to be carefully conserved lest our grandchildren run short of it. On the contrary, as a close relative of chaos, randomness seems to be all too abundant and everpresent. Everyone has a closet or a file drawer that offers an inexhaustible supply of disorder. Entropy—another cousin of randomness—even has a law of nature saying it can only increase. And, anyway, even if we were somehow to use up all the world’s randomness, who would lament the loss? Fretting about a dearth of randomness seems like worrying that humanity might use up its last reserves of ignorance. Nevertheless, there is a case to be made for the proposition that high-quality randomness is a valuable commodity. Many events and processes in the modern world depend on a steady supply of the stuff. Furthermore, we don’t know how to manufacture randomness; we can only mine it from those regions of the universe that have the richest deposits, or else farm it from seeds gathered in the natural world. So, even if we have not yet reached the point of clear-cutting the last proud acre of old-growth randomness, maybe it’s not too early to consider the question of longterm supply.

Christopher R. Monroe, Robert J. Schoelkopf, Mikhail D. Lukin

David Finkelstein

Michaël Esfeld, Dustin Lazarovici, Vincent Lam +1 more

The article sets out a primitive ontology of the natural world in terms of primitive stuff—that is, stuff that has as such no physical properties at all—but that is not a bare substratum either, being individuated by metrical relations. We focus on quantum physics and employ identity-based Bohmian mechanics to illustrate this view, but point out that it applies all over physics. Properties then enter into the picture exclusively through the role that they play for the dynamics of the primitive stuff. We show that such properties can be local (classical mechanics), as well as holistic (quantum mechanics), and discuss two metaphysical options to conceive them, namely, Humeanism and modal realism in the guise of dispositionalism.

Michaël Esfeld, Dustin Lazarovici, Vincent Lam +1 more

The article sets out a primitive ontology of the natural world in terms of primitive stuff—that is, stuff that has as such no physical properties at all—but that is not a bare substratum either, being individuated by metrical relations. We focus on quantum physics and employ identity-based Bohmian mechanics to illustrate this view, but point out that it applies all over physics. Properties then enter into the picture exclusively through the role that they play for the dynamics of the primitive stuff. We show that such properties can be local (classical mechanics), as well as holistic (quantum mechanics), and discuss two metaphysical options to conceive them, namely, Humeanism and modal realism in the guise of dispositionalism.

Sean A. Hartnoll, Subir Sachdev A, Tadashi Takayanagi +3 more