Science does not ask “Why?”

Science is both a body of knowledge and an investigative process. It is systematic structuring of doubt and it advances by observation, hypothesis, and experimental falsification (photo is a frame from the movie Monty Python and the Holy Grail, depicting Sir Belvedere preparing a scientific experiment).

Because it can only answer “What?” and “How?”
There comes a time for every graduate student pursuing a doctorate in philosophy (PhD) when they must narrow down their research interests and make a commitment to a dissertation topic. Usually, they’ve had a general sense of the field in which they’re working, they’ve read an extraordinary number of research papers and books on their topic (so they understand where the knowledge gaps, or areas of ignorance are to be found) and they’re on the cusp of advancing from student to a more mature status we call a candidate. Maarten van Doorn just published an article that included a few paragraphs about autonomy, and it reminded me that he may be at or near this stage.

There are typically two approaches for formalizing or structuring their research: 1) hypotheses, 2) research questions. They are not mutually exclusive, but most students will either choose one or the other. The hypotheses approach is more popular in engineering (my field) and physical sciences, which lend themselves to experimental falsification. The best hypotheses are conjectures, or guesses, about the relationship between independent and dependent variables. Thus, they are stated in a way that suggests the experiment that might falsify them. (If it can’t be falsified by experimental investigation, it’s not a hypothesis. It’s just a crackpot idea).

Most of the students I work with start with the research question approach, at least at first. Its seems easier or less formal, but the fact is that only the wrong questions come easily. Asking the right question takes practice.

Often, that practice comes in the form of a conversation that sounds something like this:

Student: Thank you for meeting with me today Dr. Seager! I want you to know that I’ve decided on my research question! I’m going to study, “Why is the sky blue?”
Me: That’s wrong.
Student: Wait, what? How can a question be wrong? I thought only answers can be wrong?
Me: Of course questions can be wrong. Your question is wrong.
Student: What’s wrong with it?
Me: As a doctoral student, your job is to use science to create new knowledge, and science is not equipped to answer “Why?” questions.
Student: But that’s exactly what science is supposed to do! Aren’t we trying to explain things as in, A causes B causes C and so that’s why we have C?
Me: No. It is true that science investigates causal chains, like A — >B — >C, but that’s not the answer to a “Why?” question. It’s the answer to a “How?” question. Science does not answer why.
Me (again): For example, suppose that your research question was restated as, “How is the sky blue?” then we could create model of light diffraction and we could show how the atmosphere splits sunlight into different spectral components, with these wavelengths going in this direction and those wavelengths going in that directions and we could say, “Well, the sky is not always blue, but these are the mechanisms that operate on sunlight and the conditions under which the sky is blue, or red, or orange, or green, or gray or black.”

Photo by Lightscape on Unsplash
Student: That’s unsatisfying. I became a PhD student because I wanted to understand why things are the way they are..
Me: Then you will be sorely disappointed by your studies
Me (continuing): Science is very, very good at answering “What?” questions, such as “What are the colors of the sky?”
And science is pretty good at answering the “How?” questions, such as, “How did these colors get here?” but science is unable to answer “Why is there a sky? Why do we have color?” We can describe gravity and thermodynamics and how the atmosphere formed, but we cannot say why it all exists.
Student: But science does explains gravity! And it explains why the planets orbit the sun, and the atmosphere clings to the earth!
Me: No. Science answers like, “What is the universal gravitational constant that predicts the motion of the planets around the sun?” It does not answer, “Why is this the gravitational constant, rather than some other?” or “Why is the speed of light what it is?”
Science only answers “What is the speed of light?” and “How does the speed of light relate to our perception of color?”
It does not tell us why!.
Student: That contradicts everything that I’ve been told in my life up to now!
Me: Congratulations. You’re on your way to completing your studies.
Student: When I was a kid, my parents used to read me the Just So Stories by Rudyard Kipling, like “How the Elephant Got its Trunk” and stuff like that. I used to love the stories. But then I discovered that they weren’t true. It was like Santa Claus! My parents had been entertaining me with all these lies! That’s when I knew I wanted to study science, so I could understand the truth of things.
Me: Well, you will have to give up certain childish misconceptions about science to become a scientist. First, Santa Claus is real. Second, Kipling’s stories are a terrific introduction to Darwin’s theory of natural selection. It’s more scientific than you think. Notice that Kipling never wrote a story called, “Why the Tiger has Stripes,” he always titles his stories “How…”?
Student: How can Santa Claus be real?
Me. The evidence is pretty convincing. The theory of Santa Claus predicts presents will appear under a certain type of tree, on a certain hour, at a certain day. And the experimental results are consistent with this theory. There the presents are, under the trees. Moreover, they are marked, “from Santa Claus.” I have millions of data points on this one, and the experiment is replicated with great success every year.
Student: But it’s the parents that put the presents under the tree! Not some obese, bearded old man with flying reindeer!
Me. Then we shall revise our model to accord with the evidence and call the parents, “Santa Claus.” Anybody with a desire to give anonymous gifts can be Santa. You can be Santa, because Santa is a conceptual symbol for generosity — for obtaining the feeling of giving a gift without any expectation of reciprocity. Discard the flying reindeer, but keep the concept and you’ll see that Santa is real, and important to helping us understand human behavior and emotions.
Student: Why do we have this concept called Santa Claus?
Me: I don’t know. I’m a scientist. I don’t answer “Why?” questions. That’s a different profession.
Student: I thought I was making progress, now I’m just confused.
Me: This type of confusion is progress. If you want to answer “Why?” questions, then you need a system of belief. I think it was Feynman who said, “Religion is a culture of faith; science is a culture of doubt.”
Science only moves forward by discovering things that are not true — by falsification.
Industry, business, and most other professions do not concern themselves with what is true or false. They concern themselves with what works.
Science is about discovering falsehoods. Religion is about having faith in the belief that some things are true.
You would do well to confine your dissertation to questions of “What?” and “How?” and leave the “Why?” questions to story-tellers and prophets.
Students: That’s it? Just change my question words?
Me: Getting the question right is the most important thing that a Doctor of Philosophy must be able to to do.
Too often, we underestimate the importance of understanding our question. When you get lost in your search for knowledge, ask yourself, “What question was I trying to answer?” and see if that helps you find your way again.