Dyson Spheres are hypothetical collections of technological material orbiting stars and collecting large amounts of their flux to do some sort of work. Only recently have their observational consequences been carefully quantified and have detailed searches and upper limits been possible for them.  One challenge is determining the optimal configuration of material given assumptions about the nature of the work done, which has been debated in the gray literature.  One suggestion is that the optimum configuration for computation is a set of spheres nested like Matrioshka dolls ("a Matrioshka brain"), which each shell exploiting the waste heat of the next shell in.

To resolve this, I will explore the thermodynamics of blackbody radiation and its use in heat engines, a topic that is surprisingly unsettled in the literature and the topic of recent work. I will use the Landsberg formalism to derive expressions for the work done by Dyson Spheres in the cases of computation, radio emission, and habitation, and solve for their optimum configurations in the limits where mass is and is not at a premium. I will show that Matrioshka brains are actually not computationally optimal, and attempt to use these insights to glean some clues about the likely observational properties of nearly complete Dyson spheres.

Seminar held in 538 Davey or via Zoom:

https://psu.zoom.us/j/93131536409