… on every occasion, Maxwell’s Queen of Heaven seems to proclaim her triumph, the triumph of the physics of laws over the physics of phenomena.
… I want to try to create interest, through the question of her triumph, in all the different possibilities that the history of this triumph has silenced.
This is from Cosmopolitics I by Isabelle Stengers (2003):
In 1873, the English physicist James Clerk Maxwell wrote to his colleague Peter Tait: “But it is a rare sport to see those learned Germans contending for the priority in the discovery that the second law of thermodynamics is the Hamiltonsche Princip. … The Hamiltonsche Princip the while soars along in a region unvexed by statistical considerations while the German Icari flap their waxen wings … amid those cloudy forms which the ignorance and finitude of human science have invested with the incommunicable attributes of the invisible Queen of Heaven.”
The German physicists, here Rudolf Clausius, Hermann von Helmholtz, and Ludwig Boltzmann, fought for the honor of who would be first to demonstrate that the law of increasing thermodynamic entropy was derived from Hamiltonian mechanics. And Maxwell laughed, or sneered. He knew that the characteristics of dynamics, the Queen of Heaven, the science of celestial trajectories, were incommunicable. Hamiltonian dynamics is indifferent to the statistical considerations through which the Germans attempted to associate it with the cloudy forms of thermodynamics. A phenomenon defined in terms of thermodynamics cannot satisfy the requirement of mechanics.
… At the time when he wrote to Tait, Maxwell had already invented a small but “very observant and neat-fingered being” capable of sorting the molecules that we — ignorant beings with finite capacities — can only describe “in mass.” In 1974, “Maxwell’s demon” was born, once and for all in the words of his colleague William Thomson. And the function of this demon was to show that “the dissipation of energy” whose inevitable nature the second law of thermodynamics proclaims, is in fact the result of our finitude and ignorance. “It is only to a being in the intermediary stage, who can lay hold of some forms of energy while others elude his grasp, that energy appears to be passing inevitably from the available to the dissipated state,” wrote Maxwell in 1872.
Maxwell’s demon is still with us: his presence is explicit whenever a physicist addresses a nonprofessional audience, but it is implicitly required whenever it is necessary to introduce an approximation that allows us to proceed from a “fundamental level of description” to an “observable property.” And on every occasion, Maxwell’s Queen of Heaven seems to proclaim her triumph, the triumph of the physics of laws over the physics of phenomena. We have indeed entered a new history, one that confirms what I have previously called the “psychosocial type” of physicist, who is identified by a vocation: the ability to transcend disparate phenomena and their associated operational know-how and access a unique and objective vision of the world, independent of human prejudice and interest.
… But, one might object, is this situation really so new? Doesn’t Laplace’s old demon bring about the same hierarchization? Isn’t Maxwell’s demon the same thing in a new context? Don’t both demons entrust probability with the responsibility of articulating our uncertain world and the “objective” reality ruled by law? Yet, from the ecological point of view, the identity of a being includes the way it forms relationships with other beings. From this point of view, the similarity between the two demons is greatly attenuated.
Laplace’s demon, which appeared in the introduction to his Essai sur les probabilités of 1814, had as its principal, and even sole, function to ensure a peaceful coexistence between the deterministic world of the laws of motion to which it had access and all the situations where probabilities impose their relevance upon us. Laplace’s demon did indeed affirm a hierarchy, but it was a hierarchy from which no particular consequence followed for physicists, and which imposed no obligations upon the users of probabilities. He annoyed the philosophers, but caused no controversy. He assumed a place in a rather old history characterized by the philosophical conflict between atomists and Aristotelians concerning the nature of movement, or the theological question of the possibility of privileged relationship between matter as devoid of final causation and the intelligibility of the world as a divine creation.
Maxwell’s demon, on the other hand, introduces a hierarchy within physics, a discrimination between different practices of knowledge that are addressed by the same phenomena but correspond to distinct requirements and obligations, between which a value judgment can operate. The creation of a hierarchy of this type constitutes a crucial moment from the ecological point of view, and the event takes place at a precise moment. It would not have been possible during the first half of the nineteenth century and, one way or another, its consequences would be stabilized only during the early years of the twentieth century, when the great theme of the physicist’s vocation was being introduced. In the case of Maxwell, the Queen of Heaven, already invoked by Laplace’s demon, confirmed her power, and that power was threefold.
The power of the Queen of Heaven is already manifest in the fact that the “German physicists” criticized by Maxwell appeared to have succumbed to her seductions. While Maxwell was able to satisfy himself with a technical finding — the “attributes of the Queen of Heaven” are incommunicable — the Germans were led to believe it was possible to “really” extend those attributes to the world of thermodynamic phenomena. She triumphed a second time through the value judgment that claimed that thermodynamics is based on an artificially created resemblance with dynamics: the Queen of Heaven has the power to disqualify what, for some physicists of the period such as Pierre Duhem, represented a conquest of rationality, the abandonment of any “metaphysical” claim in favor of a sober and lucid relationship between rational description and experimentation. And, with Maxwell’s demon, she finally claimed the power of a vision of the world. The “incommunicable attributes” of the Queen of Heaven would then have been communicated to the population of molecules the demon manipulates so that all forms of energy are equally available. The jurisdiction of dynamics appears to have been extended to all the phenomena described by thermodynamics.
The threefold power that singularizes the Queen of Heaven is new. Contrary to Laplace’s demon, it has nothing to do with an all-purpose rhetoric but reflects a vocation with consequences for the physical world and the physicist.
… It seems that the Queen of Heaven has been endowed with the power of defining the truth of all natural phenomena, of escaping the singularity of dynamic systems her “incommunicable attributes” make explicit. But where does this power come from?
We need to frame this problem based on obligations that correspond to an ecology of practices, that is, without endorsing the result, but also without condemning it in the name of consensual norms. Also, it is important to avoid depriving it of its interest, for example, by referring to all-purpose “macro-causes” such as the irresistible attraction of a determinist understanding or the imperative seduction of explanations that extend “beyond phenomena.” For the “ecological” possibles whose existence is at stake have meaning only if they meet the challenge of acting as vectors of new interests. Here the ecological possible entails the production of different modes of relation among the various contemporary protagonists of the triumph of the Queen of Heaven, whether these are physicists who proclaim their faith in her, other practitioners who are judged by her, or the “public at large,” for whose fascination she has been presented. I want to try to create interest, through the question of her triumph, in all the different possibilities that the history of this triumph has silenced. To the extent that those possibles are not foreign to the problems posed today by physics, they might prepare the ground not for the conversion of the physicist, but for a moment of hesitation. To make room for hesitation is not to suggest new paths for contemporary physics. New paths are not mine to envisage. They belong to those who would create them.