Let’s do it. Let’s practice Bayesian inference.
Knowing that I like this sort of thing, Malcolm Hill pointed me to a discussion group on Bayesian ecology.
It’s probably a mistake to wade into such a controversial topic, but anyway, here are some thoughts on Robert Wright’s Op-Ed in Sunday’s NY Times. Wright’s clearly a thoughtful guy who knows about both science and theology. I haven’t read his book, but I have read a number of reviews of it, heard interviews with him, and read his guest blog posts on Andrew Sullivan. He seems to be someone worth paying attention to. But …
The headline of the piece is “A Grand Bargain Over Evolution.” The goal seems to be to lay out a stance that will turn down the heat in the evolution wars and help everyone to get along. An excerpt:
The first step toward this more modern theology is for them [religious believers who have problems with Darwinian evolution] to bite the bullet and accept that God did his work remotely €” that his role in the creative process ended when he unleashed the algorithm of natural selection (whether by dropping it into the primordial ooze or writing its eventual emergence into the initial conditions of the universe or whatever).
Essentially, he’s proposing Deism, justified by a sort of God-of-the-gaps approach. I’m sure he would say that’s an oversimplification. Read his piece for yourself and see whether you think I’ve characterized it fairly.
I have two thoughts on this attitude (neither original, I’m sure, given the vast amount that’s been written on these subjects):
President Obama’s commission to examine possible options for the future of human space flight is getting ready to issue its final report. They are apparently discussing seven different possible options, some that involve going to Mars, and some that don’t. There was an interesting report in Nature last week about a recent public meeting held to discuss the various options. (Thanks to my brother Andy for pointing this out.)
Of course, I’m most interested in the implications for science, so this caught my eye:
The panel plans to cost out the scenarios by next week, and also to assess the benefits of each for 12 key areas.
One of those areas is the potential to gain scientific knowledge from each strategy, says panel member and astrophysicist Christopher Chyba, of Princeton University in New Jersey.
To that end, yesterday’s meeting was mostly devoted to presentations from scientists representing four communities supported by NASA: Earth sciences, space-borne biological and physical science, astrophysics and planetary science.
So what did the scientists have to say? Well, according to Nature one of them didn’t have much of a case to make:
Anthony Janetos, representing Earth sciences, was hard-pressed to find an example. The director of the Joint Global Change Research Institute in College Park, Maryland, Janetos hedged when panel member and former astronaut Leroy Chiao asked if the thousands of pictures he took during shuttle flights were really all that useful. Janetos said they were “marginally” useful.
The others seem to have more sanguine views of the potential for getting science from human space flight. The astronomer Marcia Rieke naturally and correctly pointed to the Hubble Space Telescope, which has been incredibly productive and has always depended on humans in space for support. Planetary scientist Steven Squyres says there’d be a big scientific payoff from sending humans to Mars, comparing a human mission to the Spirit and Opportunity rovers:
He said that astronauts on Mars could do in a minute what his rovers averaged in a day, and pointed out that Spirit and Opportunity had covered less ground during their entire mission than Apollo astronauts in a lunar rover were able to travel in a day.
Of course, the fair comparison is between what humans could do and what a robotic mission could do if it had the same budget as a human mission (i.e., thousands of times what was spent on Spirit and Opportunity). I doubt very much that the humans would win out in that comparison.
I doubt that you can ever justify sending humans into space on scientific grounds. But that’s not and never has been the reason we send humans into space. If we send humans to Mars, it’ll be for the intrinsic awesomeness of the achievement. Personally, I don’t think that awesomeness is worth the price at the moment. I think if we’re going to spend upwards of $1011 on engineering and R&D, it should be on a massive investment in energy technology for Earth. If we do send humans to Mars, of course, I reserve the right to think it’s awesome and to be excited about it.
By the way, one of the Augustine panel’s seven options is particularly baffling to me: “what the members called the "flexible path," which would avoid the "deep gravity wells" of the Moon and Mars, saving the time and cost of developing landers to carry astronauts to the surfaces of those bodies.”
A flyby of the moon might be followed by more distant trips to so-called Lagrange points, first to the location where the gravity of the Moon and the Earth gravity cancel each other out, then to where the gravity of the Earth and Sun cancel out. There could also be visits to asteroids or flybys of Mars leading to landings on one or both of the low-gravity moons of Deimos and Phobos.
This seems to me to have most of the disadvantages of human space flight but to cut way, way back on the advantages, i.e., both the scientific payoff and the intrinsic awesomeness.
The obvious question is what’s the point of such a thing. The editors address this in a letter accompanying the first issue, making a number of valid points: Good research is sometimes wrongly rejected. Moreover, there’s value in publishing even results that turn out to be dead ends, if only to prevent other people from wandering down the same dead ends. But here’s where they fail to convince me:
While such a project as Rejecta Mathematica would have been impracticable in the pre-internet age, the ï¬‚ood of resources available today begs another oft-posed question: "Why do we need a new journal? Isn't this what a preprint server (like the arXiv), a blog, or a personal website is for?"
My usage-pedant hackles get raised at the misuse of “beg the question,” but that’s not really the point. Mostly, I just don’t think they have a good answer to this question. This journal would solve some of the problems the editors have identified, if the right people would read it. But I don’t see how that’s ever going to happen. In particular, an author who wants to get people to notice his rejected paper can and should put it on the arXiv, which will be a much more effective strategy than publishing it here. [Note:The arXiv does require an "endorsement," but frankly, the bar there is set pretty low, and if you can't get someone to endorse your paper, that's a pretty solid indication that you need to fix either the work or your communication skills.]
Still, Rejecta Mathematica is an interesting experiment, and I hope it does prove useful to some people. The editors did get one thing exactly right: along with each article, the authors must supply an open letter explaining the rejection history of the article. These letters are extremely revealing: some contain reasoned discussion, while others are frankly rants. If I were to look at this journal regularly, that would be my main guide as to which articles were worth a closer look.