90% True

Posted By Caulimovirus on January 23, 2010

.: Over at Evangelical Realism, Deacon Duncan has a post up on The New Materialists, which you’ll be surprised to learn are actually the people in the pro-life/anti-abortion contingent. It’s a good read overall, but there’s one passage that I want especially to emphasize because it’s a topic I’ve been thinking about recently:

The material universe is not just a universe of substances, it is a universe of substances and processes—nouns and verbs. And the verbs are no less important than the nouns.

.: The context of the passage is about what makes us human. To wit, it’s not just the unique combination of chromosomes in our nuclei that makes us who we are; what those chromosomes do matters as well (case in point: twins).

.: But, since this is my blog, I want to bring things back to my lab. On my bench is a little brown vial full of ethidium bromide. If you were to ask me what ethidium bromide is, I could give you two types of answers: the noun version, which is “a large aromatic compound with a phenanthridine core, two primary amino groups, a perpendicular phenyl group, and a bromide ion, with the chemical formula C₂₁H₂₀BrN₃,” or the verb version, which is “the stuff that makes DNA visible under UV light.” Both answers are true. The former is what ethidium bromide is according to the organic chemist, and the latter is what ethidium bromide does according to the molecular biologist.

.: But I have a suspicion. I suspect that, if we pursue a reductionist line of inquiry, we’ll always arrive at a final answer that’s phrased entirely in the verb form. So ethidium bromide has a phenyl group. What’s that? It’s a ring of six carbon atoms and five hydrogen atoms connected to another molecule. What’s a carbon atom? It’s a type of atom with six protons, six electrons, and six, seven, or eight neutrons. What’s an electron? It’s a negatively charged particle that’s comprised of . . . of . . . itself? That doesn’t really tell me anything. What does it mean to be negatively charged? Negatively charged particles repel positively charged particles. That sounds like a verb definition. What else is there? Well, when electrons are in motion, they generate magnetic fields. Okay, that tells me something, but what’s a magnetic field…? And so on.

.: That’s one example I just pulled out of my derriere. And I’m no physicist, so it’s highly probable that I’m lacking key electron-related insights. But I have one really good reason for believing my suspicion to be true: all justified statements in science ultimately depend on measurement, and a lot of measurements scientists make are indirect.

.: For instance, if a biochemist wants to know how much protein is in a sample, the most direct method would be to count each individual strand and tally them up that way. We can’t do that, so we have another method that exploits what proteins do: they absorb UV light around 280 nm in wavelength. So, shine some UV light through a blank sample, see how much makes it through, then shine the same light through the real sample and see how much less makes it through. Subtract the latter from the former, multiply by a constant, and there’s your answer.

.: But then, I’m giving too much credit to the “direct” method of just counting individual proteins. Even supposing we could see proteins with the naked eye (we can’t, but that doesn’t hurt the point I’m about to make), what we’d be counting are the little things that excite the rhodopsin in our retinas, triggering a sequence of reactions that ultimately ends in a mental visualization of the stuff we perceive as proteins. That’s a lot of processes, a lot of verbs.

.: So where does it end? Or where, even, does it start? If we’re defining all things in terms of what they do to other things, how can we avoid circularity in definitions? How can we progress in our understanding if we don’t have any solid grounding for our terms?

.: As you’re pondering this question, take a look around you. Or heck, keep looking straight forward. You’re surrounded by things that work. You’re reading this off an electric doohickey that’s sending electrons and photons and magnetic fields every which way, and we have a pretty good idea of what’s happening inside that amazing little box of yours because it keeps happening for you, me, and billions of other people every day. How can we progress without solid grounding? Who cares? We do.

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