Columnists Ti:Sapphire laser gain simulation

Published on January 10th, 2012 | by Nicene Guy


Acts of Faith in the Sciences

The idea that we have faith in everyday matters is not new. This secular faith is practiced by, well, everybody, since we rely on a sort of faith that our senses do not deceive us in perceiving the world around us. This sense of secular faith is no less apparent (and certainly no less important!) in the sciences. Indeed, we have some amount or other of faith in each step of the “process” for a given experiment, which we exercise quite unconsciously.


Faith in Theory

It’s been said before that a scientific theory is a sort of story which we tell ourselves to makes sense of some set of (presumably repeatable) data. Well and good. But what reason do we have to believe that our “story” describes reality—and especially, that it holds true anytime, anywhere? What reason do we have to believe that it really describes the natural world as it is?

It is worth noting here that a great many theories—at least in physics—begin with any number of assumptions. There is a joke that physics never works in real life because most objects aren’t spheres and very few of us actually live in a vacuum. We often, moreover, ignore any number of “small” interactions when deriving our formulas [1], which interactions may not actually be ignorable, and may play a large or a small part in any given interaction; these interactions may or may not be separable from the particular interaction or effect in which our theory takes some interest.

Lest we argue that these theories are validated by observation, it’s worth considering an observation of a different kind. In his Aquinas; A Beginner’s Guide, Professor Edward Feser notes that

“a serious problem with the idea that science is merely in the business of establishing regularities on the basis of observation is that the sort of regularities that the hard science tend to uncover are rarely observed, and in fact are in ordinary circumstances impossible to observe. Beginning students of physics quickly become acquainted with idealizations like the notion of a frictionless surface, and with the fact that laws like Newton’s law of gravitation strictly speaking describe the behavior of bodies only in the circumstance where no interfering forces are acting on them, a circumstance which never actually holds. Moreover, physicists do not in fact embrace a regularity as a law of nature only after many trials, after the fashion of popular presentations of inductive reasoning. Rather, they draw their conclusions from a few highly specialized experiments conducted under artificial conditions. None of this is consistent with the idea that science is concerned with cataloging observed regularities.”

I might include here a note about simulations—the other side of theory work—which are often used to help in the design of an experiment (on the one hand) and to “test” a theory (or, for that matter, to develop it). Simulations very often do a good job of predicting how an experiment will work out—that’s why we use them, of course—and allow us to test our theories in the “idealized” environments for which they are written.

Ti:Sapphire laser gain simulation

On the other hand, the simulation [2] may or may not perform in the same way as reality. For one, we are left to assume that the algorithms used by the simulation actually are correct. Ok, there are ways of testing some of that assumption, but then we also are responsible for including any relevant interactions—some of which may be outside of the theory, and hence not included in the simulation, either. And of course, there is the simulation result; presumably, the simulation is being used to compute a number of parameters whose value we do not know; there is thus no way for us to be certain that the simulation results are correct save to actually conduct the experiment under the same conditions as in the simulation.


Faith in Experiment

This brings me to the experiment itself. Physics, at least, and the other sciences are supposed to follow a cycle which begins with observation, then builds a theory, which it then tests and modified and re-tests and modifies some more. The observation, and especially the “testing” is done via experiment. Of course, if this process is to begin at all—let alone be successfully continued—it must begin with some amount of faith in the ability of an observer to make good observations. As the late Fr Jaki notes in his Miracles and Physics,

A panorama view of the UT^3 laser system.

Immediate and direct observation of things and the certainty of that observation (or at least the certainty with which it can be corrected or improved) is the rock bottom basis of not only philosophy but also of science as well…if it is impossible to start a march with the second step, concern about the laws of nature should give second place to concern man’s ability to register things and events with certainty. And since without that ability nothing can be known about the laws of nature, the chief intellectual concern should be not so much the possible violations of the laws of nature as about the actual violation, if not plain rape, of man’s mind whose natural function is to know reality with immediate certitude.

That is to say, without faith that our plain observations are actually correct, the whole project of “scientific investigation,” the whole foundation for science, comes undone. The French physicist Pierre Duhem explains this another way in his essay The Primacy of Common Sense:

When a sincere witness, sufficiently sober so as not to take the whims of his imagination for observation and familiar enough with the language to express his thought clearly, affirms to have registered a fact, the fact is certain. If I declare to you that on such a day, at such an hour, I saw a white horse, you must believe, unless you have reason to consider me a liar or a victim of hallucination that on that day, at that hour, in that street, there was a white horse….But…what the physicist states as the result of an experiment is not a recital of facts registered by him. It is rather an interpretation of these facts, it is their transposition into the abstract, symbolic world of theories which he considers to be well established.

Therefore, after the physicist’s testimony has been submitted to the rules which establish the degree of confidence due to the account of a witness, you have accomplished only a part, and the easier part, of the critique of his experiment.

In other words, in the sciences—and especially in the increasingly collaborative projects of modern science—we must often trust not only in our own observations, but in those of others; and moreover, since often we have only the interpretations of those observations to go by [3], we have to trust that these interpretations are correct; granted, we can offer some critique, or we can compare them with the theory—but if the whole point of the experiment is to test the current theory, then it would be begging the question in favor of said theory to reject our experimental findings solely because they conflicted with the theory.

Even when the data is our own, the task of interpretation is never an easy one. Theories often predict smooth curves (for a graph, that is) where data is jagged and discontinuous; there are frequent statistical fluctuations, and the conditions of two data runs (or, for that matter, two shots from a laser) are seldom if ever really identical. There are indeed some rather famous experiments whose outcome has come down to a judgment call on the part of the investigators.

(Above) THe mode as seen by the human eye (or a simple handheld camera), and (below) the central part of the mode as seen on a lab ccd camera.

All of which becomes a great illustration of G.K.Chesterton’s observation in Orthodoxy that

It is idle to talks always of the alternative of reason and faith. Reason is itself a matter of faith. It is an act of faith to assert that our thoughts have any relation to reality at all. If you are merely a sceptic, you must sooner or later ask yourself the question, “Why should anything go right; even observation and deduction? Why should not good logic be as misleading as bad logic? They are both movements in the brain of a bewildered ape?” The young sceptic says, “I have a right to think for myself.” But the old sceptic, the complete sceptic, says, “I have no right to think for myself. I have no right to think at all.”

Reason itself is, after all, based at least in part on our ability to take what we know [4] and apply it to a given situation or question. Thus, if we cannot have so much faith as to even believe in our senses, our interpretations of the information which we collect through those senses, or for that matter to believe the plain testimony of other eyewitnesses who collect the information firsthand, then we leave reason (to say nothing of science!) without a meaningful leg to stand upon. Granted, we can spend time (and money) in the lab verifying every finding which we make–we usually do this to some extent–and in turn every finding which our colleagues and competitors make (again, we sometimes do this), but more often than not, we place some amount of faith in our results: enough, that is, that we cannot claim to be skeptics. Indeed, a great many discoveries rely on our trusting that our senses do not deceive us at every turn, whatever our predictions say ought to have happened: scientific advances ultimately rely on so many “small” acts of scientific faith.



[1] So for example, any field which uses perturbation theory relies on the assumption that we can make a Taylor series expansion of one variable, which expansion requires that this variable be small if the expansion is to be useful. Among others, the field of nonlinear optics is especially reliant on this particular approach.

[2] Understand, of course, the simulation can be “checked” by calculating something easy first, that is it can be run against some standard theory or experiment the results of which are well-known. On the other hand, these results are “well-known” only because some previous experiment was conducted to get those results. Not to mention that it is a bit of a leap of faith to assume that when a simulation gets the physics right for a simple scenario, it will therefore get the physics right every time in a more difficult and complex scenario.

[3] Consider that there is a joke, which is not too far from the truth, that anything in a presentation or paper labelled “typical data” really means “the best set of data I have from all the thousands of trials I ran, the only shot which shows exactly what I wanted all this data to show.”

[4] Knowledge does, after all, come to us through the senses—and I don’t think we have to take St Thomas’ word for it.


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About the Author

JC is a cradle Catholic, and somewhat of a traditionalist conservative. He earned his Ph.D. in physics from the University of Texas at Austin in the summer of 2014. He is currently a tenure-track assistant professor of physics at a university in the deep south. He is a lay member of the Order of Preachers. JC has been happily married since June of 2010. He and his lovely wife have had two children born into their family, one daughter and one son; they hope to have a few more. He has at times questioned – and more often still been questioned about – his Faith, but he has never wandered far from the Church, nor from our Lord. “To whom else would I go?”

  • Amanda Castro

    When I was studying for my Bachelor’s in Mathematics, people would often respond with the question “how do you balance faith and science?” Even though math isn’t the most “controversial” of the sciences everyone just assumed I played with numbers. This post is a great reminder about how faith and science are integrated.

  • Loved it that the pictures you use are from LabVIEW, the product I work on.

  • @Devin: I didn’t realize that you worked for NI. I have a brother-in-law who works there, too (though not on LabVIEW itself). LabVIEW is my default go-to program, both for simple simulations work and for device control (though I’m not necessarily a computers wiz…).

    @Amanda: I get that question a lot too, even from fellow people of faith. I just tell them that there’s not much of a balancing act to it, unless you want to count balancing the time needed to be scientific researcher (and grad student) with the time needed to be involved with the Church. Now, dealing with colleagues who are hostile to the Faith, that’s another issues: but it’s not by any stretch one which is unique to the sciences. We just tend to get more folks who have a scientistic, materialistic, or utilitarian outlook. I imagine that you probably faced the same in your field.

  • What a wonderful post!

    It is true that we must adopt a metaphysical assumption (at least one) in order to do science: we must assume that what we observe is “real”.

    But it doesn’t stop there.

    Operational science; that is, observational/experimental science, can be assumed to be worldview neutral.

    For example, we all can agree that blood cells, collagen, and soft tissue exist in Cretaceous dinosaur bones

    But our metaphysical assumptions (worldview) will determine how we interpret the observational data.

    The Darwinist immediately assumes that we have discovered some unimagined way that organic substances can be preserved 80,000,000 years.

    The young earth creationist assumes that we have observational, empirical falsification of the theory of evolution.

    Which is right?

    As a matter strictly of science- that is, observational, world-view neutral science…..

    The young earth creationist is right.


  • UPDATE: Very important piece of the puzzle concerning Mary’s Bones.

    It is looking very likely indeed that observational falsification of the neo-Darwinist hypothesis has *already been obtained*, ironically enough, in the form of a 2008 study attempting to refute the claims of Schweitzer, et al.

    It turns out they conducted C14 tests on the organic material, and…………..

  • Great post! I would add one comment to the balancing act. Although people may think they are in an uncontroversial area of science (I’m in computer science, for example), they need to still be vigilant. I worked on a project once that looked at indexing DNA, which is pretty harmless, all things considered. I was responsible for soliciting test strands from our collaborators for doing all of our benchmarks. All was well and good, and then a few months later, I learned through a news article that my university does a lot of dabbling with embryonic stem cells, including the labs I was obtaining test sequences from. It never occurred to me to think to ask about that. I have no way of knowing now if they were or not, but it certainly shattered any belief I had that I was immune from the moral quandaries that face biologists and should carefully weigh the research I perform.

    On a lighter note, I would consider one of the greatest acts of faith in the sciences to be actually finishing grad school. ^_^

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