October 27, 2013
Now that school is back in full swing, I’ve decided write a post about how I view science. I love to use the word model when talking about science. To me a model is a way of seeing things. It’s the framework in your mind that makes sense of things. For example: think about the way you think of the calendar year. What do you visualize in your mind? Do you see calendar pages? Do you see seasons? Do you see birthdays and holidays embedded into each month? What you “see” is an example of a visual model.
It turns out that you have models in your head for everything. You have models for why its colder in the winter. You have models for why we get sick. You have models for how a car works. Our brains like to make sense of the world and so they create these models without us even consciously thinking about it. All of our models are based on our experiences. Sometimes our experiences are limited so our models may not be very good (meaning that they don’t fit reality all that well).
Science is simply a big long-term project of trying to come up with better and better models for nature. It’s a group project where science-types collect evidence that lets them refine their models over time. What we teach in the classroom are the best models science has to offer right now. The history of science has taught us that they change and that’s the way we make progress. It doesn’t mean that the previous models were bad or didn’t explain things correctly, it just means that we have a fuller understanding of what is happening. New information was incorporated into things resulting in a better model.
For example, people had known for hundreds of years before Isaac Newton’s time that there was gravity that pulled things downward. Newton, though, wondered if the force that made an apple fall to the ground could somehow be the same force that held the Moon in orbit around the Earth. He had no idea why the apple or the Moon would both be attracted to the Earth, so he made an assumption that maybe all things with mass attract all other things with mass. He then worked out the his calculations (he also helped invent a little thing called Calculus!) and came up with a mathematical model that described the strength of gravity. According to his model the gravitational force depends on the amount of mass of two objects and how far apart they are. The model worked very, very well. It correctly accounted for the moon’s path around the earth and also for all of the planet’s paths around the Sun.
Now fast forward to the start of the 1900s. A young scientist by the name of Albert Einstein wondered if there was another way to think of gravity. He speculated that maybe things with mass somehow change or warp the space around them. What to us looks like the moon being attracted to the Earth is really just the Moon following the natural curves of this warped space. He also cranked out some calculations of his own and we call his model the theory of general relativity. It totally changed the way we see the fabric of the universe. It correctly predicts everything that Newton’s model of universal gravitation does PLUS it explains how light can be bent by objects with mass. The extreme example being a black hole–an object that warps space so much that not even light can escape!
It isn’t that Newton’s model was bad. It wasn’t. We still teach it and use it all the time. It was incredibly accurate. It’s just that Einstein’s model is better. It better fits the test-able world around us. That is the nature of science. It is messy and sometimes filled with dark alleys and dead-end streets, but it is the only game that experiments and data and reasoning can play. It is not a collection of facts or laws of nature, but a process of constructing meaning out of the world around us. If students better understand that, then we as science educators are on the right path.