Last Monday, I wrote about where facts come from. Since the post focused on the peer-review process used to check scientific data before it’s published, I probably should have called it “How We Know Scientists Aren’t Just Making Stuff Up.”
Today, I thought I’d back up and do a quick review of the scientific method – the actual process by which new knowledge is created, before flint-hearted reviewers tear it to pieces and put it back together better.
There are a ton of kid’s books out there on the scientific method, but I am partial to the one I wrote (shocking, I know!). I don’t just love it because it’s mine, though. I love it because I think it’s a more accurate reflection of how scientists actually spend their days than the overly optimistic version you probably learned in elementary school. 😀
Step One: That’s Funny…
As Isaac Asimov is rumoured to have said:
The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka!” (I found it!) but “That’s funny …”
In my experience, this is totally true. In real life, the first step in the scientific method is typically observation: noticing something that strikes you as unusual. The phrases, “huh,” “weird,” and “oh, crap what was that?” are also relevant at this stage.
Step Two: I Have a Theory…
Step two involves forming a hypothesis: a possible explanation for whatever you just observed. It is not actually a theory. In science-speak, a theory is a hypothesis that has been so thoroughly tested, and explains so many observations, it is the closest thing to gospel truth we can actually get. I called this step “I have a theory” because the “Once More With Feeling” episode of Buffy the Vampire Slayer is one of the best things I’ve ever seen on TV, and it gave me some much needed laughs on this Monday morning. 😀
My point (and I swear I had one somewhere) is that the hypothesis is a possible explanation for the phenomenon. In the real world, we often stop once we have one, because as long as the explanation fits with our existing world view, we tend to accept it as fact and go about our day.
Scientists are not allowed to get away with that.
Step Three: Let’s Do an Experiment!
An experiment has one purpose: to test a hypothesis. The trick is designing an experiment that will isolate and test a SINGLE explanation for an observation, out of the million other things that COULD be going on.
Let’s say you noticed that the houseplant in the shady corner of the kitchen didn’t grow as well as the one on the sunny counter. Your hypothesis is that plants need light to thrive. So you get two new plants of the same variety, plant them in the same size pot, with the same soil and water and fertilizer levels. Then you put one in the sun and one in the shade and see what happens. Since you controlled for all other possible explanations, you can be pretty sure that the plant in the shade died from lack of light.
Let’s see you’ve noticed that obesity rates among black and Latino Americans tend to be higher than they are in white Americans (which is true). How do you isolate genetics from income, geography, access to nutritious food, access to health care and nutrition education, cultural and dietary preferences, genetics, and the million other factors that could be contributing to this observation? Especially when, generally speaking, it’s either not practical or not ethical to stick your human research subjects in a metaphorical shady corner?
Yeah. Not so easy. If you’ve ever wondered why scientists sometimes seem to be contradicting each other, it’s because science is hard, dude.
Step Four: That’s Funny…
At this stage, lucky scientists now have evidence that supports their hypothesis: facts and data that suggest their explanation was probably right.
Of course, real life is messy, so what generally happens is that every time we “answer” one question, two more questions pop up all hydra-like. Which is why scientists usually say their data “supports” the hypothesis, or that an explanation is “likely” to be true: it’s always possible that new data will arrive and start the whole ball rolling again.
Most people find this really annoying. “Eggs are healthy, eggs are death, oh wait eggs are healthy again – why can’t scientists make up their MINDS?” we wail. But to me, this is exactly why science is SO AWESOME. The notion that we don’t know everything is build right in, so when new information presents itself, we can adapt. Science is both humble and flexible, and those are things we could all stand to be a bit more often.
What about you? Fond memories of science experiments as a kid? Frustrated by flip-flopping accounts of science in the media? I love hearing from you!