Monday, April 16, 2012

Science is Real

The highlight of our weekend was a trip to a local science expo. It had a bunch of local exhibitors, including Lafayette College, which had a sign that was not printed out, but rather lettered with black magic marker, which didn't exactly scream "prestigious engineering school" to me.

Lily posed in front of a dinosaur made out of balloons  and someone dropped a balloon-cage model of graphene from the ceiling around kids.

"We are the tiny dinosaurs!"

There were even some non-balloon-related activities. One was at a booth from the Da Vinci center. Kids could put a cube of dry ice into a genie lamp and deliver some water via a pipet, and the vapor would come out of the nozzle. I thought that was pretty neat, but the woman talking to her called it an "experiment".

That kind of bothered me, because I do try to speak with precision and part of the problem with the debate over global warming is that the general public uses "Theory" to mean something very different than the scientific community and the differences in understanding between the two uses has allowed Creationism a lot more traction than it deserves.

I think They Might Be Giants said it best:

"A scientific theory isn't just a hunch or guess--it's more like a question that's been put through a lot of tests."

I can't find the book right now (which is the story of my life), but I think it was Carl Sagan in his excellent book, "The Demon-Haunted World"  (Though it could also have been Richard Feynman's biography "Surely You're Joking, Mr. Feynman!") that an exhibitor with thousands of dollars of scientific equipment who does a gee-whiz presentation isn't really performing an experiment, but somebody who flicks a light switch on to see if it works is.

And let's back up a bit. The books I mentioned aren't scientific works. They're for popular consumption. But they do make some of the most eloquent and compelling arguments I've ever read for the use of critical thinking in everyday life. Back when I first started dating Jen, I looked through one of her textbooks. Now Jen comes from more of an educational background and I come from more of a scientific one. I criticized the book because I thought the concepts were oversimplified, and she rebutted that it was for kids, and the purpose wasn't to provide an exhaustive education on the subject, but to expose them to it, give them a grounding and cultivate that sense of wonder. And as is so often the case in our relationship, Jen was right.

So that's the purpose of the Expo, and I'm not going to criticize DaVinci too hard for that flub. It was a little bit sloppy, but talking to a five-year-old isn't writing for a peer-reviewed journal.

And I'm pleased with Lily's sense of wonder. She really tries to figure things out. Her grandmother bought her a little dolphin-headed grabber from a local store the other week. And Lily was looking at it one evening and suddenly exclaimed that she had figured out how it worked, and proceeded to explain it in breathless detail. "There's a wire attached to the handle inside and it pulls on the rubber band, and that's hooked on the other end on the inside of the mouth..."

In Chapter 2 of  his excellent book  "Why People Believe Weird Things" Michael Shermer recounts the story of a dig with Jack Horner, curator of paleontology at the Museum of the Rockies in Bozeman, Montana:

The initial stage was "getting the fossils out of the ground; the second was to look at the fossils, study them, make hypotheses based on what we saw and try to prove or disprove them"..."Paleontology is not an experimental science; it's an historical science," Horner explained. "This means that paleontologists are seldom able to test their hypotheses by laboratory experiments, but they can still test them"  How?

In 1981 Horner discovered a site in Montana that contained approximately thirty million fossil fragments of Maiasaur bones, from which he concluded "at a conservative estimate, we had discovered the tomb of ten thousand dinosaurs"... The hypothesizing began with a question: "What could such a deposit represent?" There was no evidence that predators had chewed the bones, yet many were broken in half, lengthwise. Further, the bones were all arranged from east to west—the long dimension of the bone deposit. Small bones had been separated from bigger bones, and there were no bones of baby Maiasaurs, just those of Maiasaurs between nine and twenty three feet long. The find revealed more questions than answers. What would cause the bones to splinter lengthwise? Why would the small bones be separated from the big bones? Was this one giant herd, all killed at the same time, or was it a dying ground over many years?

An early hypothesis that a mudflow buried the herd alive was rejected as "it didn't make sense that even the most powerful flow of mud could break bones lengthwise ... nor did it make sense that a herd of living animals buried in mud would end up with all their skeletons disarticulated." Applying the hypothetico-deductive method, Horner formulated a second hypothesis: "It seemed that there had to be a twofold event, the dinosaurs dying in one incident and the bones being swept away in another." Since there was a layer of volcanic ash a foot and a half above the bone bed, volcanic activity was implicated in the death of the herd. Deduction: because the fossil bones split only lengthwise, the damage to the bones came long after the event that caused death, which might have been a volcanic eruption, especially since volcanoes "were a dime a dozen in the Rockies back in the late Cretaceous." Conclusion: "A herd of Maiasaura were killed by the gases, smoke and ash of a volcanic eruption. And if a huge eruption killed them all at once, then it might have also killed everything else around," including scavengers or predators. Then perhaps there was a flood, maybe from a breached lake, that carried the rotting bodies downstream, separated the big bones from the small bones (which are lighter), and gave them a uniform orientation. "Finally the ash, being light, would have risen to the top in this slurry, as it settled, just as the bones sank to the bottom." What about the baby Maiasaurs? "Perhaps the babies of that year were still in the egg or in nests when the volcano erupted, or perhaps nesting had not even begun." But what about babies from the previous season who would now be juveniles? Horner admits "that nobody knows for sure that these dinosaurs would have produced young each year"

Even in the first stage of a dig while fossils are being released from their rocky shroud, the hypothetico-deductive method is constantly applied. When I arrived at Horner's camp, I expected to find the busy director of a fully sponsored dig barking out orders to his staff. I was surprised to come upon a patient historical scientist sitting cross-legged before a cervical vertebra from a 140-million-year-old Apatosaurus and wondering just what to make of it. Soon a reporter from a local paper arrived (apparently a common occurrence as no one took notice) and inquired of Horner what this discovery meant for the history of dinosaurs. Did it change any of his theories? Where was the head? Was there more than one body at this site? And so on. Horner's answers were consistent with those of the cautious scientist: "I don't know yet." Beats me." "We need more evidence." "We'll have to wait and see."

That's what each of us in our own way, Jen, me, the people from Da Vinci, are trying to teach Lily. If something doesn't make sense to you, don't give up! Keep poking at it until it does.

And on Saturday, right after the show, when Jen was taking care of something and Lily and I were taking a walk, Lily was examining her Pez dispenser and she started telling me about how that worked. I'm happy that she really wants to understand the world around her, and when faced with something she doesn't immediately understand, she doesn't throw up her hands and say "Tide goes in, tide goes out, you can't explain that!" but instead  starts working on an explanation that matches what she sees. 

I think Lily's been doing this just because she has a kid's natural curiosity about the world. Jen thinks she's been doing it because I've been encouraging it and she likes the attention it brings. Which one of us is right? I don't know yet.

We need more evidence.

We'll have to wait and see...

1 comment:

  1. Great post, Josh! (from your wife)