Sunday, August 31, 2008

Pretty Mercury

Nearly two months ago, I posted a piece on MESSENGER's imagery of Mercury. A couple of days later, I did a post on our current ideas about how the inner Solar System formed, and how recent telescope observations of other star systems have informed those hypotheses. I keep intending to get back to that thread, to make it clearer just how it is that a silica-rich Mercury is a confounding conclusion: not at all what we would have expected. On one hand, while it's frustrating when observations and results from the real world are not consistent with an otherwise coherent body of ideas, on the other hand, that conflict is the greatest kind of opportunity that scientists ever get: to rewrite a great deal of what we thought we knew.

One of the central ideas I always try to get across to people is that ALL science is, in principle, tentative. That is, scientists should not (and cannot honestly) claim absolute certainty. That is not to say that aren't some ideas so well tested that it's essentially meaningless to question them. The effects of gravity, the centrality of evolution to biology (to the point that some have suggested evolution is the central characteristic- the defining characteristic- of life), the periodic nature of elements, the central framework of plate tectonics, and others, are all so well established that only in an attempt to be contrary would any scientist question their validity. But in principle, any of these ideas could face a challenge from observed reality. Rather than representing a weakness, this principle of tentativeness is in fact science's greatest strength. It forces the discipline as a whole to be self-correcting. When a scientist finds evidence (observations) that are in conflict with what his or her peers believe to be true, that community must determine whether the purported evidence is accurate, and if it is, how to restructure the knowledge base to accommodate the new evidence. Many established scientists, whose careers have been based in the old knowledge structure, may feel threatened, and resist change and new ideas. Others may have felt nagging uncertainties for a long time, and burst forward with excitement and creativity.

But the important part is that science as a whole, and all of its disciplines and sub-disciplines, is frequently called upon to accommodate unforeseen results and observations. Yet at any given time (because of the self-correcting nature of the process), the best way to predict some particular outcome is to look at what science at the time would predict. This ultimately is the payoff of science: not that it is "true," or that it gives us insight into the nature of the universe, or that it elevates us flawed mortals to some superior plane: science does none of those things. What it does do is allow us to make ever more accurate predictions to questions like "What would happen if we did this?" and "What will we see if we look here?" Because of its pragmatic basis, science excels at answering pragmatic questions.

And one of the most exciting things that can happen is to answer a question incorrectly. That means we have a good chance to learn something new.

I sort of got off into a more philosophical post here than I had intended, but the relevant news is that the full sized image of Mercury is the Picture of the Day at the Red Orbit site. And I do find it pretty exciting. Also, wonderfully beautiful.

Yeah, that's another thing science is good at: finding stuff that is just stunningly, awesomely, mind-bogglingly, beautiful.

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