The Power of Science - Island of Sanity

Island of Sanity


The Power of Science

The Uniqueness of Science

Science has proven to be an incredibly powerful tool for gaining knowledge. Science moves forward and progresses in a way that no other approach to knowledge does.

Compare to politics. About 420 BC Plato wrote a book called The Republic in which he discussed the pros and cons of different forms of government. You can read this book today and see that the discussion has changed little.

Compare to philosophy. The ancient Greeks debated questions like, How can we know what is good? What is love? What is beauty? What is the nature of reality? People today debate the same questions, often with the same arguments.

What's the difference? The Scientific Method. The classic scientific method works like this:

  1. Formulate a theory, some idea about how you think the universe might work.
  2. Make a prediction based on the theory. If the theory is true, than if we do X, Y will happen.
  3. Perform an experiment to test the prediction.
  4. Confirm, refute, or modify the theory.

An experiment can prove a theory true or false. No other approach to knowledge is able to dispose of theories like this.

Suppose two scientists have competing theories. To take a simple but real example: Suppose one scientist thinks that heavy objects will fall faster than light objects. Another scientist thinks that objects will fall at the same rate regardless of their weight. Each can present plausible arguments why his theory makes more sense. But ultimately, they can and did resolve the disagreement by performing an experiment: Go to the top of a tall building, drop two objects of different weights, and see if the heavy one hits the ground first or if they hit at the same time. When Galileo actually performed the experiment, they hit at the same time. Question resolved.

Oh, of course in real life it's not that simple.

Sometimes an experiment is theoretically possible but impractical or even impossible. Theoretically we could test if there is life on other planets by travelling to other planets. Of course in practice we don't have the technology to do that yet. Sometimes there are ethical considerations. We could test Near Death Experiences -- claims of people that they have seen an afterlife -- by killing a large number of people, trying to revive them, and questioning those who were succesfully brought back, performing neurological tests, etc. The catch, of course, is that we'd fail to revive many of the test subjects, and so to get useful information we'd have to kill hundreds of people.

More mundane but probably more important: The results of an experiment can be misleading. Like in the falling object example, if you drop an iron ball and a feather, the iron ball does in fact fall faster. Observations like this are probably what led to the theory that heavy objects fall faster. Advocates of the "same speed" theory said that this was because of air resistance. When they dropped two objects in a cylinder from which the air had been evacuated, the two objects fell at the same speed. The Apollo 15 astronauts dramatically performed the experiment on the Moon. (See YouTube.) But the point is, many very smart people were fooled for centuries by a misleading experiment.

So science is certainly not all-powerful and infallible. But it is very powerful.

Other Approaches to Knowledge

Think about how other methods of gaining knowledge work.

History: If two historians have conflicting theories about what happened in the past, they each put forward the ancient texts and archaeological discoveries that back their theory. But how do we know if some ancient book is accurate? Maybe the writer (or the sources he relied on) were mistaken or confused about what actually happened. Maybe he lied -- for example to make his own country or faction look good and his enemies look bad. We have two accounts of the Battle of Kadesh, fought circa 1274 BC. The Egyptian account says that the Egyptians won. The Hittite account says that the Hittites won. How can anyone prove, 3000 years later, which is true?

Politics: If two political activists have conflicting ideas, they each present logical and moral arguments. But how can I prove that my idea about what is just and fair is correct and yours is wrong? As I write this, the U.S. is debating immigration laws. Some say that illegal immigrants who have jobs and pay taxes and haven't committed any crimes should be given amnesty. Others say that this is unfair to those who are trying to follow the legal process and play by the rules. There is little debate about provable facts. The question is one group's idea of what is right and good versus another's, and it's difficult to see how either could prove that they are right and the other side is wrong.

Mathematics: If two mathematicians disagree, they each present a mathematical proof, which is essentially a logical argument. They each look for flaws in the other's argument. Unlike politics, there is objective truth. In principle, you could study both proofs until you find which one has an error. In practice, finding such an error can be enormously difficult. Back to this point in a moment.

Theology: If two theologians have conflicting theories, they each identify passages in sacred texts, or present logical or historical arguments. The other side claims that their books are not really inspired, or that they are misinterpreting them or taking passages out of context. The nature of the debate ends up a lot like debates about history: there are many cases where two theories are equally plausible and there's no real way to prove one or the other. Theological arguments are often a combination of historical and philosophical reasoning.

The Limits of Logic

Outside of science, many approaches to knowledge ultimately rely on logical arguments. A carefully thought out, well-presented logical argument can sound very convincing. But it's easy to miss subtle logic flaws.

I'm a software developer by profession. Computer programs are a lot like logical arguments: we go step by step through some logical process to go from inputs to outputs. When I was first learning to program it struck me that computer programs are a lot like mathematical proofs.

But with software, we can do an experiment to check our logic. We usually set up a simplified or scaled down situation for a test. To take a trivial example, suppose we wanted a program to add up thousands of numbers. We'd write the program and then have it add up three or four small numbers. We then manually perform the addition and make sure the result is correct. When we can confirm that it can correctly add up three or four numbers, than we trust its results when it adds up a thousand.

And here's the thing: Anyone in the software business will tell you that it often happens that a program does not give the correct results, but we can't see any flaw in the logic. I recall one time that we ended up having the entire department, a dozen or so skilled, experienced professionals, studying a program, and no one could see the flaw. But we knew it was wrong because it gave incorrect results. We figured it out eventually, but it took hours before someone got a brainstorm and saw the problem.

So I often muse: How often have I heard a logical argument for some political or philosophical or theological idea, and found it very persuasive and convincing ... and in fact it contains a critical logic flaw? How could I know for sure? If the issue is controversial in the place and time where I live, people who disagree with the argument will search for flaws and point them out. But what if a flawed idea is accepted as "common knowledge"?

Unscientific Ideas

Perhaps I need to say that I am not deriding other fields of study. Historians, philosophers, etc, do not fail to use the scientific method because they are stupid. They don't use the scientific method because it is not applicable to their fields. Take history. If someone said that he didn't believe that Julius Caesar ever lived, there is no experiment we can perform to prove he did. Any experiment we do is in the present, and Julius Caesar lived in the past.

Side note: Historians sometimes perform experiments to test the practicality of a theory about how something was done in the past. The TV show "Mythbusters" did a segment where they tried to test the claim that Archimedes had built a "death ray" in 212 BC by attempting to build such a device using technology that was available at the time. (You Tube) Such experiments certainly qualify as "science", because they are experiments (duh!). And they can certainly be interesting. But note that they cannot truly resolve an historical question. The fact that something could have happened in a certain way doesn't prove that it did happen. And, frankly, the fact that a modern person can't figure out how to do something using tools available at the time doesn't prove that a person living then couldn't do it. Maybe he was smarter than you are.

It follows, then, that "unscientific" does not mean "stupid" or even "wrong". At least, not if by "unscientific" we mean "not proven by the scientific method". There are lots of ideas that are unscientific that I have just as much confidence in as I have in scientific theories. I am quite certain the American Civil War was really fought. I am quite certain that the paintings of Rembrandt and Da Vinci are better art than my clumsy sketches -- I can barely draw a recognizable stick figure. I am quite certain that murder is morally wrong. Etc.

I can't prove any of these things with a scientific experiment. But the fact that a question cannot be attacked with science does not mean that the truth is unknowable. We can be pretty confidant that Julius Caesar did indeed live even though we can't prove it scientifically. It certainly does not mean that there is no truth other than scientific truth. Even if you want to quibble about Julius Caesar, if you want to insist that maybe all the history books and inscriptions on monuments and so on are lies or mistakes and we can just never know for sure, still, there is an objective truth. Caesar lived or he didn't.

Not Science

Sometimes, often, people confuse technical language or use of fancy gadgets with science. They are not at all the same thing.

For example, consider speculations about whether there is life on other planets. Someone might discuss this question bringing in facts about astronomy, like discoveries of planets orbiting other stars. He might formulate ideas about what a creature would have to be like biologically to live in an environment unlike Earth. He might talk about what sort of technology an alien race might have.

But until he proposes a practical experiment, none of this is "science". Until he actually performs the experiment and analyzes the results, it is all simply philosophical speculation. His speculation might draw on scientific facts, but that does not make it science. His speculations may be plausible or they may be insane. I might think that his speculations are plausible while you think they are insane, or vice versa. And that's the point. Until he can perform an experiment to test his theories, they are not science. They are just speculation.

You sometimes hear of "scientific methods" being used to test some fundamentally non-scientific question. Like I've seen documentaries about archaeology that talk about modern "scientific methods of archaeology", like ground-pentrating radar to find artifcats buried beneath the surface, or radiometric dating to estimate dates of artifacts. Sorry, but these are not "scientific methods of archaeology", because they do not in any way rely on experimentation and observation to prove a theory about history. What experiment is being performed? Yes, the technology may indeed help the archaeologist to find the desired artifacts. I'm not saying that these gadgets are not useful. But the use of advanced technology does not make something "science". If I type an editorial explaining why my favorite candidate should be elected, using the most advanced computer available, while riding on a jet plane, and talking to my colleagues over a satellite phone whose battery was charged with nuclear power, that does not make my political opinions "scientific facts".

A pet peeve of mine is that reports in the media about science are often totally confused on this point. I often see news stories that say that something is a "scientific fact" because some organization with the word "science" in the name said that they took a vote of their members and the majority said it was true. Sorry, but that has nothing to do with science. Science means facts that can be demonstrated to be true by experiment and observation. It most certainly does not mean that you should believe anything that a man who calls himself a scientist says is so. That is the opposite of science. That is anti-science.

© 2015 by Jay Johansen


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