Dyson VS Sagan on Nuclear Winter

I do not wish here to get into a technical argument about the details of nuclear winter. I will merely summarize my own struggles with the technical issues. I spent a few weeks in 1985 trying to make nuclear winter go away. The phrase "go away" here is used in the sense customary among scientists. To destroy a new theory, you try to find a simple situation where the theory predicts that something happens and you can prove that the same something does not happen. Then you say that the thing pr...

 Seeing Dyson Civilizations

In summary, the circumstellar shells of Dyson civilizations-at temperatures ~300 degrees K and radii ~1 a.u.--can be detected with existing telescopes and state-of-the-art infrared detectors in the 8-13-u window out to distances of several hundred parsecs. But discrimination of Dyson civilizations from naturally occurring low-temperature objects is very difficult, unless Dyson civilizations have some further distinguishing feature, such as monochromatic radio-frequency emission.

 Encapsulation Serves a Purpose

The quintessential example of the open ideal showed up in Freeman Dyson’s otherwise wonderful piece about the future of synthetic biology in the New York Review of Books. MIT bioengineer Drew Endy, one of the enfants terribles of synthetic biology, opened his spectacular talk at Sci Foo with a slide of Dyson’s article. I can’t express the degree to which I admire Freeman, but in this case, we see things differently. Dyson equates the beginnings of life on Earth with the Eden of Linux. ...