Tuesday, February 19, 2013

Scientifically Proven is an Oxymoron

Today I would like to discuss my view of the nature of science. In today's world, we hear a lot about science education, STEM, or preparing our kids to be innovators and solve all the world's problems through technology. By elevating science to this pedestal, I think we often lose sight of what doing science actually means. 

Science is nothing more than a buzzword for logic. 

If you have ever taken a course on logic, you will learn about how to make a sound argument. I tell my students that an understanding of logic will help them win fights with their parents and they usually perk up. I will tell you that it may help win arguments with your spouse, but in my experience, that isn't the case. 

A sound argument has to pass two tests. 
  1. It has to be based on true premises. A premise is a true statement that you argument is based on. 
  2. A valid inference has to be made regarding the relationship between the premises. An inference is a decision that you make about the premises. 
Let me give you an example: 
  • All students in my high school wear jeans. John is a student in my high school, so thus John wears jeans. 
This seems like it follows. The premises are that students at my school wear jeans, and that John is a student.  The inference is that because both of these are true, John thus wears jeans. If either of the premises is false, or if your inference that John will always follow the status quo is invalid, this argument falls apart. 

Another example: 
  • Your own son is not getting his homework done so you tell him he can't go to the dance this Saturday. 
Seems reasonable as well, but here is how he can attack the argument. 
  1. Attack the premise. "Dad, I do have my homework done, your premise is false, so your argument is unsound."
  2. Attack the inference. "Dad, you are right, I don't have my homework done. But you are assuming that if I stay home, I will be doing my homework on Saturday night. That is not going to happen."

Nothing is True in Science

In science, we all our premises "observations" and our inferences "hypotheses". Our arguments are called conclusions that are debated endlessly. I start my year in physics with this lecture and by telling my students that nothing that I tell them in the next 18 weeks is true in the truest sense of the word true, meaning fact. SCIENCE IS NOT INTERESTED IN FACT. 

Science is interested in IDEAS. Science begins with observations, the statements that you are basing your conclusions on. No measured observation is true; they all have error to them. I will never know exactly how long my computer screen is as the measurement depends upon the tool that I use. Eyeballing it, I can say it is about 18 inches. With a meter stick, I may be able to measure to the nearest 0.1 mm, and with some "laser" device, I may get better than that. However, I will never know the true size of it. All measurements have error. If observations are our premises, then none of our premises are entirely true. This all of our conclusions are unsound due to false (to a degree) premises. 

As it turns out, there is no such thing as a completely valid inference as well. Anytime a human makes a decision, it could be wrong. When a scientist decides on a hypothesis, or what she thinks is going to happen, there is a chance it could be wrong. 

Science does not "PROVE" anything. Science puts forth ideas on why we think things happen. If those ideas hold over time, we call them theories, and then laws. At no place in the scientific method is something proven true meaning fact. There is a chance that tomorrow someone could discover something that will throw every law in your textbook to the wind. That is the nature of science and it has happened before. 

The Law of Conservation of Mass and the Law of Conservation of Energy are the two most fundamental laws of nature. We base almost all of our other laws on these two. Einstein broke both of them with E=mc^2. This change in our fundamental understanding of the universe shook the scientific community and is still doing so today. Hell, we just learned what mass really is in finding the Higgs Boson!

The Law of Gravity seems pretty stable. Things fall when dropped. It has remarkable predicting power. If I drop a hammer today it falls, if I drop it a week from now, it will still fall. One of the biggest unanswered questions in science is "what is gravity." No one knows. Aristotle had ideas, Galileo and Newton had different ones. Einstein had a different idea, and today our particle physicists have even different ones. (Don't get me started on string theory). 

Why do we study science?

Science is a process, not a set of facts. In science education, we hear a lot about the scientific method and problem solving. We see a lot of project-based learning initiatives where teachers give students a problem and ask them to solve it using this method. This seems great as kids are engaged in the process. However, without the basic ideas that underlay our understanding of the universe, students have no premises to base their solutions on. I want the engineer that builds the I74 bridge to know something about Newton's Laws and forces. There has to be a happy medium between knowing the underlying principles of science and engaging in the process. 

We study science to help us make decisions. Global warming... is it real? I can tell you that I am on the fence on this one. I have seen data for both sides and need to study it more to make an informed decision. It is okay to say that you don't know and need to look into it more. That is more acceptable to me than saying that we are all going to burn up next year because Al Gore says so.  Students need this freedom to make informed decisions about policies that will change the world. 

If you have any thoughts on the basis of science or science education, I would love to hear them.