|Diagram from Kasting and Harman showing how close|
Earth is to boundary of Habitable Zone.
"Increased insolation threshold for runaway greenhouse processes on Earth-like planets" by Jérémy Leconte et al. in Nature shows that if the earth were 5% closer to the Sun then we'd be subject to runaway greenhouse processes and all the water would evaporate. This isn't exactly a fine-tuning argument but what it does show is that "Habitable Earth-Like Planets" are appreciably rarer than conventionally thought. I suspect that it will turn out that the tolerance between habitability and the Earth's present characteristics will be about +5% in each direction - and here we find a -5% constraint. (Kasting and Harman is the News and Views paper in Nature that comments on Leconte at al.)
|Fig 3 of Brockmann and Hebling shows how, by plotting the |
arrival of an epidemic and looking at the Effective Distance
of these arrivals, the correct source can be identified.
This is a completely beautiful paper, which not only allows an approximate de-coupling of the geometry and the epidemic characteristics but enables the source of an epidemic to be identified. There is a very good "Perspective" on this by Angela MacLean.
There is also a review of a fascinating book called Complexity and the Arrow of Time with a chapter by Simon Conway Morris ("Once there were bacteria, now there is New York") and a moving obit of my son's PhD Supervisor Michael Neuberger in Science. May he rest in peace and rise in glory.