It has been a while since anything has been posted on this blog. I am sorry. I have been busy wrapping up my year of teaching. Now that school is finally over for the year, I have more time to post to this blog.
This post is going to be a long one. I am going to post a project I have been working on. The project is an article about the limitations of science. It is standard for an introductory science textbook to give a brief explanation or a history of the scientific method. However, these textbooks almost always focus on the mechanism of the scientific method: they do not touch on the philosophy of science. That is something that I think is desperately needed in our society today. In a society where science and technology plays such a significant role in our daily lives, we need a reminder that science is not paramount. Science has limitations.
Science does not merely have limitations because there are topics science shouldn’t study. Everyone acknowledges (or at least pays lip service to the idea) that science does not play a role in morality or ethics. The common example is cloning: science can tell us whether cloning is possible but ethic and morality tell us whether cloning of humans should happen. Everyone acknowledges that science should be kept out of certain topics. But that is not the type of limitation I am talking about. Instead, I am talking about the limitations of science within science itself. The problem with separating science from something like morality and ethics is because it leaves the impression that science reigns supreme in its domain, it just has to leave other domains alone. Science is supreme when it comes to the natural world, but science shouldn’t throw its weight around in metaphysics. However, science is not supreme in the natural world. Science has logical limitations that restricts its authority even within the realm of the natural world.
We need to understand this limitation, because science should not be treated as an absolute standard. Unfortunately, it is treated as such. That is why learning, at least a taste, of the philosophy of science is so necessary, to tamper our society’s reverence for science. That is the purpose of this article that I have been working on.
My intent is for this article to be read by my college students when we begin a science course. However, I want to share it here, as well, in order to spread the word about the limitations as much as possible. Note that this article is not intended to be apologetic. It leans into that a little bit toward the end. The main thrust is simply to note that science has a limit.
Here now is the article:
Science and the Assumptions that we Make
Science can be a contentious issue. It is used to rally people to a particular political position, such as when people are encouraged to “go green” to save the planet. Other times, it seems to butt heads with religion, such as when those who believe that God created the world around 6,000 years ago (creationists) clash with scientists who hold to the theory of evolution. Do these conflicts arise because people are stubborn and refuse to accept what science truly reveals? Let us consider a couple of examples to explore this question.
Is Microraptor a Dinosaur or a Bird?
In 2003, a new fossil species was described. It was named Microraptor gui, and despite the fact that it had clear impressions of feathers, it was classified as a dinosaur.[1] Many paleontologists hailed it as the definitive example of a feathered dinosaur: unlike the other feathered dinosaurs that had been discovered up to that point, there was no question that Microraptor has feathers. And since these feathers were found attached to a clearly dinosaurian body, it must be a feathered dinosaur.
However, not everyone was convinced. There was, and continues to be, a small group of dissenting paleontologists who insist that Microraptor is not a dinosaur at all. Instead, they see Microraptor as a bird, and thus insist that there is still no such thing as a feathered dinosaur.
How did we get two such widely different interpretations of Microraptor? It is quite simple, really: there are two widely different interpretations of how to define a dinosaur. On view, which we might call the traditional view, uses features of the skeleton to define a dinosaur. Things like a perforated acetabulum, a compressed tarsus, and two postorbital fenestra. Moreover, each dinosaur group has its own set of unique characteristics. And, since Microraptor has all of the hallmarks of a dromaeosaur, and since dromaeosaurs have all of the hallmarks of a dinosaur, Microraptor must also be a dinosaur.[2] The dissenting opinion, however, approaches the definition of dinosaurs quite differently. Instead of noting features of the skeleton, they note a particular style of locomotion. They insist that dinosaurs[3] were all ground-running, bipedal animals. Since the fossils clearly indicate that Microraptor was a very adept climber, and not a ground-dwelling runner, Microraptor can not be a dinosaur.[4]
Notice that this difference of opinion has nothing to do with the evidence. Both groups of paleontologists see and study the exact same thing: fossils of Microraptor. They can even agree upon the descriptions of those fossils: both groups have the same general idea of what Microraptor looked like and how it behaved. The difference is entirely in their definitions.
Helium Diffusion in Zircon Crystals
RATE is an acronym for Radioisotopes and the Age of The Earth. It was a research project conducted by several creation scientists that ran from 1997 to 2005. The purpose of RATE was to test the assumptions made in radioisotope dating and to see if those assumptions were supported by the evidence.
One of the keystone papers that came out of RATE was “Young Helium Diffusion Age of Zircons Supports Accelerated Nuclear Decay” written by Dr. Russell Humphreys.[5] Humphreys’s article is detailed and thorough, but to greatly simply it, he looked at zircon crystals found in rocks dated at 1.5 billion years old using radioisotope dating. However, the decay of these radioisotopes also creates helium inside of the zircon crystals. Rather than measuring the rate of radioisotope decay, Humphreys measured the amount of helium remaining inside the crystals. Given enough time, the helium will diffuse out of the crystals. If the rate of diffusion could be measured, then the amount of helium remaining in the crystals could be used to determine the age of the crystals.
Humphreys discovered that the rate of helium diffusion and the amount of helium remaining gives an age of 6,000 years for the very same rocks that are given an age of 1.5 billion years using radioisotope dating. So Humphreys was faced with a question: one rock is giving two ages. One age is very short (6,000 years, obtained by measuring helium diffusion) and one is very long (1.5 billion years, using radioisotope dating). They cannot both be correct, so which one is wrong? Humphreys concluded that the helium diffusion age was correct. He reasoned, in part, that “the preponderance of Biblical and geoscience evidence for a young world points to a change that would only affect dating methods which depend on slowly-decaying nuclei.”[6] The “slowly-decaying nuclei” refers to radioisotope dating, so Humphreys is rejecting an age of 1.5 billion years old, in part, because such an age contradicts the genealogies of the Bible.
Now, it is not fair to say that Humphreys was solely persuaded by the Biblical evidence. After all, the preceding quote mentions evidence from the geosciences. However, it is still important to note that he admits that he reached the conclusion that helium diffusion was a better determiner of age than radioisotope dating because of Biblical evidence. He mentions a preponderance of evidence and the Bible as part of that evidence. One has to wonder, would the evidence have been less preponderant without the Biblical evidence?
Now, let us take the exact same evidence but look at it from a different perspective. Suppose we have a scientist who, unlike Humphreys, does not place a great amount of significance on the Bible. Rather, this scientist holds natural laws as the only possible explanation for past events. He can also observe the rate of helium diffusion in zircon, the amount of helium remaining in the zircon, and the amount of helium generated by the radioisotope decay, all of the same same things Humphreys observed. However, when it came time to ask the question, which dating method is reliable, rather than looking at the Biblical evidence, he would consider the invariability of radioisotope decay. It is well established that no physical phenomenon can affect the rate of radioisotope decay.[7] In contrast, diffusion can be affect by things like lattice structure, size of molecules, and temperature.[8] To a scientist who is looking for a natural explanation for the past, he can conceive of ways to alter the rate of helium decay. He cannot conceive of a way to alter radioisotope decay. By only considering natural events, this scientist would conclude that the age of 1.5 billion years old must be accurate and the 6,000 year old age is faulty.
Note that in both cases, the evidence is the same: both sides consider the same helium in the same zircon crystals in the same rocks. They differ, not because of the evidence, but because of the ideological framework used to interpret the observations.
“They” are Not in a Conspiracy
Like it or not, science is often a contentious subject. Topics likes origins (creation versus evolution) are naturally divisive, because the two sides have vastly different ideas about the nature of mankind. Topics like global warming can have far reaching effects on the policies and laws of a nation. Even “unimportant” issues, like whether Microraptor is a bird or dinosaur, can incite division when personal reputation is at stake.
We humans get defensive when our invested ideas are questioned. We draw a line in the sand and boldly declare that everyone on our side is right and everyone on the other side is wrong. Since we are dealing with science, it is easy to go a step further and declare that the evidence is definitively in our favor. But if the evidence is definitive, why do those on the other side disagree with us? The answer is simple: they are deliberately ignoring the obvious truth.
Such reasoning manifests itself in many ways. “Big oil companies pay for research that opposes the global warming consensus.” “Religious fundamentalists are so driven to defend their beliefs, they oversimplify the facts to twist it to their perspective.” “Evolutionists deliberately avoid talking about certain subjects because they know they have no answer.” In one way or another, they are in a conspiracy.
Is this what we saw with Microraptor and helium in zircon? Was the evidence so obvious, one way or another, that the opposing view can only hold to its position by ignoring evidence? No. In both cases, the schism came down to a matter of perspective. Classifying Microraptor is a matter of definition. Definitions are arbitrarily set by humans. The perspective of helium and zircon comes down to priority: does the Word of God or consistency of radioisotope decay play a bigger role in our interpretation?
The underlying problem in both cases is a lack of information. We do not know of every dinosaur that ever existed. Paleontologists continue to find and name new dinosaurs on a yearly basis. Beyond that, new information about known dinosaurs are constantly being discovered. With so much new and changing information about dinosaurs, should we be surprised that people have differing opinions of what dinosaurs are?
As for helium in zircon crystals, both perspectives are incapable of making enough observations to demonstrate that their interpretation is correct. We cannot go back a million years, 10 million years, or 100 million years to test the decay rate of uranium to show that its decay rate has remained constant over time. Neither can we go back 6,000 years to observe the diffusion of helium and observe its rate. The evidence to confirm either position is locked up in the past.
The White Swan Problem
Are the Microraptor and helium in zircon problems unique or are they representative of a wider problem? It turns out, all of science suffers from this problem. Science is about discovering and defining universal statements. A universal statement is true in all places and across all time. No universal statement can be definitively verified. The reason is illustrated by the white swan problem.[9]
Suppose we wanted to prove the statement, “All swans are white.” How can we show it to be true? We would probably begin by observing swans and noting their colors. If every swan we observed was white, would that prove the statement, “All swans are white”? Hardly. We are a finite group of people. We can observe a lot of swans, but those observations will be limited in time and space. Suppose we live in Kansas. We can make a lot of observations about swans in Kansas, but what about outside that state? We would need to make far more observations through the remaining 49 states. Still, that only gives us observations in one country. We would need to make observations in Canada, Mexico, Costa Rica, Nicaragua, and the rest of central America just to see if all swans in North America are white.
We cannot cut corners, either. We cannot skip a country, claiming that there are no known populations of swans in that country. No, we have to search every country, regardless of whether or not swans should be there, just in case there is a stray swan or unknown population.
If we cannot skip a country, then there is no place on earth that can be overlooked. To verify that all swans are white, we would need to scour every nook and cranny, explore every possible location on earth for any possible stray swan. Because all it takes is one, a single non-white swan to prove that “All swans are white” is a false statement.
Suppose we have exhaustively searched the earth. Every country was searched, no stone was left unturned, and after all of that work, we found no non-white swan. Can we now say that “All swans are white” is a true statement? No, we cannot. Swans lived in the past. Have we observed all swans and their colors in the past? Presumably, swans will live in the future. Have we observed any future swans? Perhaps some hatchling a hundred years from now will come out as some color other than white.
We can make a similar argument about any subject in science, even a law of science. Is gravity universal? Sure, it has worked every time we tested it, but have we tested it in every location on Earth? Throughout the universe? At every point of time in the past? In the future? After testing it hundreds of times and never seeing any deviation from it, we presume that it must be true at all places in all times, but the truth is, we are not able to actually test it in all places and at all times. We have to presume that our hundreds of observations are representative of the billions of times gravity had an opportunity to function.
Be it gravity or swans, we cannot make enough observations to prove a universal statement. There will always be gaps in our knowledge. Those gaps will get filled in with presuppositions: assumptions that we make before we interpret the data. Assumptions such as what a dinosaur is or whether the Bible is more significant that the natural invariability of radioisotope decay.
What Presuppositions do You Bring to Science?
Up to this point, I have tried to be as objective as possible. I cannot anymore, since it should be obvious that objectivity is now impossible. If scientific knowledge contains gaps and these gaps are filled in using presuppositions, then no one approaches science objectively. Everyone approaches science with a bias.
It may be tempting to give up and ask, “What good is science if it is not objective?” I would not advise adopting this attitude. Science is too useful of a tool. Despite our bias, science can still be used to explore and quantify the world. Technology, the application of science, be it engineering, electronics, medicine, or any number of things, is still useful to us.
However, we must remember that there are always presuppositions embedded in science, and we must be prepared to change our understanding of science if new information is discovered or if our presuppositions change. As one philosopher of science put it,
The game of science is, in principle, without end. He who decides one day that scientific statements do not call for any further test, and that they can be regarded as finally verified, retires from the game.[10]
Nothing in science is sacred. Any idea is subject to change. If anyone says, “The science says…” is not telling you what is, but what he thinks is.
That road cuts both ways. Our understanding of science is not final, either. Our understanding of science is biased. There is no way around this unfortunate circumstance.
That is why I said that I can no longer be objective. The gaps in our knowledge need to be filled. What should we use to fill those gaps?
Here is my answer: I use the Bible. For those that believe that God exists and that the Bible is His revealed word, the Bible should already be your standard. Use what the Bible says as your presumptions as you explore and and interpret science and the world around you.
Many will mock the idea of starting with the Bible to interpret science. The truth is, the Bible actually provides a consistent foundation for science. If God created the world, as the Bible says that He did (Genesis 1:1, John 1:3), then He gets to decide what the natural world is like (Job 34:13-15). He is literally the author of the natural world! Furthermore, He created humans to explore and govern the world (Genesis 1:26-28). He created us to explore and manipulate the world around us, so we can be assured that the natural world is perceivable to us. In short, the Bible gives us a sufficient foundation of presuppositions needed to explore the world using science.
For those who may be hesitant to give the Bible such a prominent place in science, or who may reject the Bible altogether, I would urge you to remember: a bias is unavoidable in science. Your presuppositions are no better than presuppositions derived from the Bible. Your science is not in a position to question the Bible.
Ultimately, it is up to you to decide what presuppositions you will bring to science.
Thoughts from Steven
[1]Xu, Xing; Zhonghe Zhou; Xiaolin Wang; Xuewen Kuang; Fucheng Zhang; and Xiangke Du (2003) “Four-winged dinosaurs from China” Nature 421: 335-340
[2]Xu, Xing; Zhonghe Zhou; Xiaolin Wang; Xuewen Kuang; Fucheng Zhang; and Xiangke Du (2003) “Four-winged dinosaurs from China” Nature 421: 335-340
[3]More specifically, they claim that theropod dinosaurs were all bipedal runners. However, since dromaeosaurs are typically classified as theropods, they conclude that Microraptor cannot be a theropod and therefore cannot be a dinosaur.
[4]Feduccia, Alan; Theagarten Lingham-Soliar; and J. Richard Hinchliffe (2005) “Do Feathered Dinosaurs Exist? Testing the Hypothesis on Neontological and Paleontological Evidence” Journal of Morphology 266:000-000 and Martin, Larry (2008) “Origins of avian flight – a new perspective” Oryctos 7:45-54
[5]Humphreys, D. Russell (2005) “Young Helium Diffusion Age of Zircons Supports Accelerated Nuclear Decay” in Radioisotopes and the Age of the Earth: Results of a Young-Earth Creationist Research Initiative, Larry Vadiman, Andrew Snelling, and Eugene Chaffin, Institute for Creation Research, El Cajon, California, pg. 25-100
[6]Humphreys, D. Russell (2005) “Young Helium Diffusion Age of Zircons Supports Accelerated Nuclear Decay” in Radioisotopes and the Age of the Earth: Results of a Young-Earth Creationist Research Initiative, Larry Vadiman, Andrew Snelling, and Eugene Chaffin, Institute for Creation Research, El Cajon, California, pg. 67
[7]Faure, Gunter and Teresa Mensing (2005) Isotopes: Principles and Applications 3rd ed., Wiley, Hoboken, New Jersey, pg. 58-59
[8]To be fair, Humphreys points out that a reduction in temperature is not enough to change the rate of diffusion to match an age of 1.5 billion years (Humphreys, D. Russell (2005) “Young Helium Diffusion Age of Zircons Supports Accelerated Nuclear Decay” in Radioisotopes and the Age of the Earth: Results of a Young-Earth Creationist Research Initiative, Larry Vadiman, Andrew Snelling, and Eugene Chaffin, Institute for Creation Research, El Cajon, California, pg. 61). However, the fact that diffusion is known to be variable while radioisotope decay is not would still lend the naturalist scientist to conclude that if any dating method is incorrect, it is diffusion of helium, not radioisotope decay.
[9]The white swan problem is referenced by Popper, Karl (2002) The Logic of Scientific Discovery Routledge Classics, London, England, pg. 4 when he talks about the logical shortcomings of induction in science.
[10]Popper, Karl (2002) The Logic of Scientific Discovery Routledge Classics, London, England, pg. 32
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