Category Archives: Science

Science is not consensus

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Writing about the nature of belief in reference to science  the other day started me thinking about other specific issues I have encountered in discussing science with non-scientists.  Coffee also helped this endeavor.

Something I hear in discussion a lot, especially about topics such as climate change and evolution, is the following: “Yeah, well, I read an article by this one guy who says that X is/isn’t true.  I thought you were all in agreement?  I guess you really don’t know, then, do you?”  You’ve probably encountered this argument before as well.  Really, it can be broken into two pieces that can be addressed individually: the consensus problem and the knowing problem.  I’ll address the first today and the second in a later post.

The Consensus Problem

The whole “I though you were all in agreement” statement falls apart once you understand that science is not a consensus.  In order for a scientific theory to be considered “true”, or more accurately, for it to be considered the working model of a phenomenon, consensus is not required.  What is required is that the presented theory fits the observed facts.  Can there be more than one model?  Sure, it happens all the time.  However, as more and more data is collected, the observations give more credence to one of the models at the expense of the others.

Take the example of the theory of plate tectonics, the idea that the Earth’s crust is fractured into many smaller plates that float around on the warm, chewy nougat mantle due to the convection of heat between the hot core and the cooler surface.  When the theory was first presented at the beginning of the 20th century, no one really took it seriously.  How could the continents drift?  That’s absurd!  In the beginning, the “motor” of convection wasn’t known.  But, similarities in fossils and a variety of geologic features seemed to point to the idea that at sometime in the past, the continents were all mashed together and then somehow broke apart and moved to their present locations.  Over the years, more and more data was presented to support the idea; the discovery of the mid-ocean ridges, the magnetization of rock samples separated by thousands of miles, the obvious jigsaw-like coastlines of the continents themselves.  Eventually, a majority of the scientific community could no longer deny that plate tectonics was the preferred model and every aspect of earth science changed.

Now, did the entire scientific community just up and decide that the theory was correct in a magical moment when every single earth scientist just said, “Yes. Plate tectonics is the way”?  No.  Indeed there was, particularly in the 1950’s and 1960’s, fierce debate over its validity.  There are probably a few outliers today that still do not accept the theory.  But, science chose the model that fit Nature.

Another possible outcome here is that one of the theories turns out to be a special case of something greater.  When Einstein presented the General Theory of Relativity, a new take on the force of gravity and the nature of space and time, the established framework of Newtonian mechanics became a subset of that theory.  Newtonian mechanics made all sorts of assumptions that, it turned out, were false.  In our every day experience, we would never notice these errors; Newtonian mechanics is a fantastic description of everyday motion.  However, go to the scale of interstellar space and it just isn’t enough to describe what we see.  Indeed, General Relativity was born from the inability of Newtonian mechanics to explain how Mercury orbits the Sun.  Again, it’s all about whether or not the theory explains the observed details, not whether every single person agrees with it.  Needless to say, Einstein’s overthrow of 300 years of theory from the great Isaac Newton did not go over well in the beginning.  But, like with plate tectonics, scientists eventually acquiesced that General Relativity was a better model, it more closely fit nature.

My point here is this: science does not require a consensus.  It doesn’t need to fit the belief structure of those observing it.  It only needs to fit the observed data.  Say you are teaching a science lab at a high school.  You give each of your 40 students an identical cube of metal and ask them to find out what it is by calculating its density.  Thirty-nine of them tell you it’s iron but one says it’s silver.  What conclusion should we draw from this?  That the concept of density is somehow flawed?  Hardly…

In a later post, I will discuss the knowing problem, an issue with deeper philosophical roots, I suppose.  Until then, I’ll brew some more coffee.

Science vs. Opinion

Early yesterday morning, I was sitting in my back yard with my wife drinking coffee and watching birds.  At some point, I mentioned off-hand that I needed something to blog about.  I had several ideas, but I couldn’t think of anything I could take from that nebulous realm of “wouldn’t it be cool…” to something that a reader would actually bother reading.  After a couple more sips, my wife says emphatically, “I know what you should write about…god damn global warming!”  I laughed and finished my coffee…and by finished, I mean got another cup.

The conversation got me to thinking about what really bothered me about discussions involving not just climate change, but a sundry of scientific topics.  It’s not whether or not people agree or disagree with the theory of, say, climate change…it’s the concept of belief.  When you hear, read, or are involved in discussions involving “hot” topics such as climate change or evolution, the counter-argument is typically phrased, “I just don’t believe in X.”  In the case of climate change, I have been told many times, “I don’t believe in climate change” or “I don’t believe that climate change is man-made.”

Of course, the word “belief” is not off limits in science.  I, for instance, believe that the graviton, the particle that mediates the force of gravity (and gives name to this blog!) exists.  There is, of course, good reason to have such a belief given the Standard Model of particle physics that predicts its existence.  Indeed, in the same way, it is perfectly valid for someone to state that they do not believe in, say, climate change.  The key difference is that if scientific evidence is presented to me that the graviton does not exist, I will happily reformulate my belief to something that more closely represents Nature.  In contrast, many (not all) people who do not believe in climate change, evolution, or whatever, maintain that belief even when presented with scientific evidence to the contrary.  In this case, the word “belief” is really taking on a synonymic definition with “faith”…and, as the Bard said, therein lies the rub.

Science is built upon facts that are assembled into theory.  The term “fact” here means something which is, at present, known to be true.  These facts and theories are not immutable; indeed, they can be altered or completely disproven over time.  In the 19th century, when men wore top hats, had long beards, and posed for awkward daguerrotypes, physicists believed that heat transfer from object to object was facilitated by an ethereal “liquid” called the caloric.  This material would pass from hot objects to cold objects and gave physical form to heat, making it a “substance” like matter.  It was a very successful theory and predicted a great many things.  It moved to the wayside, however, as the atomic picture of matter emerged; under this theory, heat is known to be a transfer of energy that cannot be used to perform mechanical work.  No one today believes that the caloric exists, though it does provide a convenient mathematical framework to explore some aspects of heat transfer.  The point is, science had an idea, it worked great, and when it was shown to be incorrect, science moved on.  Added bonus: this is where the term calorie comes from.

In contrast to this series of events, people who have a faith-based belief that something like climate change is false can be presented with evidence contrary to that belief all day and still hold on to it.  Now, when I say faith-based belief, I’m not talking about a religious belief.  I’m merely stating that if you take something on faith, by definition, it can’t be disproven.  This stance, of course, has no place in science…indeed, a faith-based belief is not a scientific belief.  As such, it is apples and oranges to respond to a scientific statement with faith-based belief.

Take the Flat Earth Society.  This is a group of people who believe that the Earth is indeed flat.  In case you don’t believe me, check this out.  Despite a ridiculous amount of evidence to the contrary, they unwaveringly believe that “the earth is a flat disk centered at the North Pole and bounded along its southern edge by a wall of ice, with the sun, moon, planets, and stars only a few hundred miles above the surface of the earth.”  If you believe this to be true, you must be taking it on faith as you have most certainly left scientific thought behind.

I suppose that’s what it all boils down to, belief in the process of science.  If you accept that science forms the framework of rational thought and that the theories it produces are indeed “of Nature”, then you are more than willing to adjust your thinking as evidence is presented on a topic.  If, however, you hold to a belief on a topic unyieldingly, even in the face of overwhelming evidence, then you must have issue with the fundamental nature of science itself.

Let me note that this argument only holds for a certain body of knowledge.  Climate change and evolution, for instance, clearly fall in the domain of scientific thought.  Religious concepts, such as the existence of God and such, do not fall in this domain.  The existence of God, for instance, can never be proved or disproven.  As such, attempting to use science to, say, disprove God is as fallacious an argument as refuting climate change because of a faith-based belief that it is not true.

So, what’s the moral of the story?  If you wish to discuss a scientific topic, you must be prepared to accept facts that are given.  In addition, you should be able to present facts that support your claim.  Conversely, if you wish to discuss a faith-based topic, you must be prepared to discard scientific, evidence-based thought, as it does not apply.  Note that this does not invalidate faith-based ideas, it merely points out that the scientific method is derived from experiment and, if no experiment can be performed, then the scientific method, an therefore science itself, does not apply.