• A Symphony of Science

    Today, an announcement came out about a paper led by Ravi Kopparapu that updates the habitable zone, moving it further out in space from host stars. I really like this paper (on which I’m a co-author) because it demonstrates how science often progresses: through a series of incremental improvements, the totality of which has profound implications for a handful of known planets. Here’s the new habitable zone, in pretty picture form (courtesy Chester Harman/Penn State):

    You see, the habitable zone reported in the paper is based on a series of simulations of planetary atmospheres. In short, they demonstrate how close a planet can be to its star before it loses its oceans to evaporation (and other processes)… and how far it can be from its star before it loses its oceans to a global freeze-out.

    But the model used in the paper is based on lots of other stuff. At its core is knowledge we have obtained by observing and simulating Earth’s atmosphere and climate. We can only do this sort of thing because we know “how climates work” from our observations of Earth! Someone built up all that science at some point. Another series of researchers – led by James Kasting – applied this science to a model we have used to study the climates of other planets. Lots of improvements were made along the way, by undergrads and postdocs and grad students.

    Inside that model are the parameters for each of the greenhouse gases included in it – water, carbon dioxide, methane, etc. And each of the parameters for those greenhouse gases were derived by other scientists. Yet another set of scientists maintain a database that contains those parameters. And… the existence of that database allowed the scientists that led this work to update the climate model with the most recent parameters for greenhouse gas absorption. These are also the same parameters that go into models of what will happen as a result of our civilization’s carbon dioxide emissions.

    So the next time you hear of someone doing “mundane/boring” measurements in the laboratory, realize how connected their work could be to multiple “big pitcure” projects. Studying a how fast a certain reaction “goes” sounds boring, but it could lead to improvements in our ability to find life on other worlds. Or it could help us protect our planet’s ozone layer. Studying the growth rate of a peculiar microbe may unlock secrets to the limits of life, and hint at new places to send rovers (or boats!). And in this case, studying and meticulously tracking how some gases absorb radiation has led to a shift in where we think life could exist elsewhere. And soon, others will likely take up this work and expand upon it, apply it to known planets, revamp it further, etc., etc.

    One might think of this as a “butterfly effect,” but that’s not quite it is it? The butterfly effect is a demonstration of chaos in complex systems. This is more… reasoned. Planned. Collaborative. This is more like… a symphony.