The Scientific Jigsaw Puzzle

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What is Science?

I have always loved a good jigsaw puzzle. There is something deeply satisfying about taking a pile of colored cardboard scraps and turning it little by little into a predetermined picture. Every piece fit into its place and every edge matched up is a small joy. Losing yourself in the exercise is a wonderful experience, whether alone or collaborating with family or friends. In my time in academia, I have found that science is a lot like a jigsaw puzzle, with reality as its picture.

I have been a teaching assistant for college physics for two and a half years. I usually try to explain the models directly as they are, and stay away from analogies. There comes a point where most metaphors break down, and you have to say, “it’s kind of like that, but really not.” The example that makes me cringe the most is the bowling ball on a trampoline analogy of general relativity. It does have similar behavior to gravity, but only by accident. But once in a while there is a metaphor that works so perfectly that even I am satisfied, and the scientific jigsaw puzzle is one of them.

Each scientific discipline is a different section of the puzzle. The pieces that look like life, we call biology. The pieces that look like rocks, we call geology. The pieces that have space on them, we call astronomy. And so on. Teams of scientists around the world collaborate, each working in their own section or subsection. Every so often, the edge of one section is found to fit perfectly against another, to much celebration. Atomic theory connects chemistry to quantum physics. Evolution is the central hub of biology, but also links psychology to the rest of the puzzle. In the past 300 years, the puzzle has been taking shape into a vast, beautiful, solidly connected picture.

Sometimes a piece looks like it fits, but the edges don’t quite match up, or there is the tiniest bit of space between the tab and the slot. When this happens, other pieces won’t connect where they are supposed to, so we have to look down the line until we find where we made our mistake. There are even now some places where the pieces do not seem to fit. The centers of black holes, and the instant of the big bang, to name a few. These are places where quantum physics—the physics of the very small—and general relativity—the physics of the very massive—collide.

There are no edges; every section either connects to another or has a frontier where new pieces are being added every day. There are even whole sections waiting to be started. For instance, we know astrobiology—the science of alien life—will connect to astronomy, planetary science, chemistry, and evolutionary biology, but we don’t have any pieces to try to fit.

Some people, claiming to be scientists, have a picture in mind already when they approach the puzzle, and try to force the pieces to make that picture. They use the pieces to make a mosaic instead of trying to solve the puzzle. This is called "pseudoscience." Sometimes the difference is obvious, but sometimes it can be difficult even for those who spend their time immersed in the mental world of science to tell at first glance. But there is a family of methods for determining how well the pieces fit together: statistics. Subjecting ideas to rigorous mathematical fires of probability is kind of like holding two pieces up to the light to see if any shines through. Under this scrutiny, the pseudoscience falls apart, and it is up to the future wholeness of the picture to sort the correct ideas from the mere good ones.

And what a picture it is! It's a picture of the vastness of space and the beginning of time, of stars and galaxies, of matter and light, of life and humanity and curiosity. And the beauty of the picture revealed makes us all the more eager to finish the holes and expand the edges, searching for new mysteries waiting to be discovered.