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Scientific Knowledge Is Money in the Bank


Mark Boslough

Skeptical Inquirer Volume 20.2, March / April 1996

If you have ever driven across northern Arizona, you have probably seen the signs along Interstate 40: ”Meteor Crater . . . the planet’s most penetrating natural attraction.”

Perhaps the slick promotional billboards enticed you to make a short excursion from your planned trip. As you neared the site you would have seen a low ridge rising from the flat desert ahead. An earlier generation called the ridge “Coon Butte,” not realizing that it was actually the rim of a three-quarter-mile-wide crater.

When you stand on the rim, you look across an expansive circular cavity in solid rock that is so wide that it changes the wind patterns and attracts raptors that soar in the updrafts. This big hole truly should be listed as one of the natural wonders of the world.

What you may not know is that a century ago Meteor Crater was the subject of a great scientific controversy, and was a focal point for defining the scientific method and promoting scientific research at the dawn of twentieth-century American technological progress. One hundred years after that debate, Meteor Crater serves as a reminder of the importance of scientific knowledge and of the scientific method to our way of life.

In early 1896, the journal Science published an address that geologist Grove Karl Gilbert (1843-1918) had recently given to the Scientific Societies of Washington. Gilbert was the retiring president of the Geological Society of Washington and one of the top scientific thinkers of his time. He had also been chief geologist of the U.S. Geological Survey until Congress slashed the Agency’s budget in half, terminating his and others’ positions. His lecture was titled the “Origin of Hypotheses,” and was a description of the scientific method.

At the center of the scientific method, he said, is the hypothesis, or “the scientific guess.” Gilbert used the origin of Coon Butte to illustrate how this works. Four scientific guesses had been made at the time. The first came from a shepherd named Mathias Armijo, who found pieces of iron near the crater and reasoned that an explosion had hurled the metal out of the ground and formed the big hole (one does not have to be a scientist to think scientifically). Geologists who came to visit the site offered two scientific guesses involving two types of volcanic processes. A fourth hypothesis was the radical idea that a meteorite had hit the Earth.

Gilbert traveled to this then-remote part of the country and made measurements to test the various ideas. Because so little was known at the time about the physics of meteorite impacts, he predicted that such a cosmic collision would have left a very large piece of iron buried under the crater. His tests failed to find the predicted iron, so Gilbert rejected the impact idea. The small pieces of iron found on the surface by Armijo did prove to be meteorites but Gilbert concluded that they fell from the sky in an unrelated event (thereby also rejecting Armijo’s idea that they came out of the ground).

Of the two volcanic ideas, one predicted that volcanic rocks would be found in the crater. But the crater had none, so there was only one hypothesis left that had not been eliminated: some type of volcanic steam explosion.

That was the idea that Gilbert accepted as the correct explanation, even though he had arrived at the crater expecting to demonstrate that it was formed by an impact. He already supported the then-unpopular notion that such craters on the moon were formed by impacts, not volcanoes, but a good scientist does not allow personal feelings to get in the way of evidence. However, Gilbert was very careful to point out that there was much that was still not known about meteorites and impacts. He recognized that new facts might be discovered that would overturn his conclusion.

That is exactly what happened. We now understand that Gilbert overestimated the size of the meteorite that would be needed to pack enough punch to blast out such a big hole: Hypervelocity impacts are much more powerful than he realized. Furthermore, even a large iron meteorite will mostly vaporize in a giant explosion, leaving very few traces. Gilbert had made a mistake by assuming that the impact would leave a lot of buried iron.

It would be many years before a young scientist named Eugene Shoemaker and his colleagues from the U.S. Geological Survey would discover a rare new mineral in the rocks at the crater, a mineral that had been predicted to form from an impact. This discovery finally settled the controversy, and partially vindicated a shepherd’s original hunch that the hole was formed by some kind of colossal explosion involving iron.

The scientific process is sometimes slow, but it always involves making educated guesses that eventually lead to predictions that can be observed and put to a test. If the predictions turn out to be incorrect, the test is still successful as long as scientists learn enough to modify the theory, find a better one, or uncover mistaken assumptions. Unfortunately, even after the successes of twentieth-century science between Gilbert’s time and now, there are a lot of people who still don't like (or don't understand) the scientific form of reasoning.

In fact, modern science is now under attack from many directions. On the left are those who twist legitimate multiculturalism by going way beyond it to extreme relativism. They dogmatically assert that all ways of seeking knowledge are equally valid, but still insist that the scientific method is flawed because it originated in a time and place that causes them to view it as a Eurocentric, white male endeavor. Such thinking has encouraged proliferation of belief in pseudoscientific and unscientific ideas ranging from crystal healing to flying saucers. Even worse, it has turned some women and minorities away from careers in science, not only to their own detriment but to the detriment of society.

Science is also under attack from the religious right, whose literal interpretation of the Bible supersedes scientific evidence, logical reasoning, and common sense. In this fundamentalist view, any fact that is at odds with their own reading of the scriptures must be ignored. Unfortunately, this faction is not satisfied merely to reject science for itself, but it now has an active campaign to remove scientifically validated subjects (such as evolution) from the classroom and have them replaced by their own unscientific opinions (such as creationism).

Worst of all, science is now under attack by a budget-cutting Congress in Washington for whom dollars have measurable value but scientific knowledge does not. Members of Congress think that spending on basic science is like throwing money into a big hole in the ground. They do not realize that a dollar saved may be two dollars (or more) worth of knowledge lost.

Gilbert closed his late-nineteenth-century address by explaining that "fertility of invention implies a wide and varied knowledge of the causes of things,” and that deep understanding of nature through scientific research is essential. Gilbert told his audience that our “material, social, and intellectual condition” advances in lockstep with our “knowledge of natural laws.”

He concluded by comparing science to an investment: “Knowledge of nature is an account at [the] bank, where each dividend is added to the principal and the interest is ever compounded: And hence it is that human progress, founded on natural knowledge, advances with ever increasing speed!”

Since Gilbert spoke these words, our scientific bank account has led to inventions that his audience in Washington could not have imagined. Our investment has swollen with the advances we associate with modern living, with medical discoveries that have given us longer, healthier, happier lives, and with an unprecedented degree of national security.

We can thank Gilbert and his contemporaries for having the foresight to recognize 100 years ago the importance of this scientific bank account, and for making the effort to convince decision-makers to restore and increase funding for science. We should again ask those in Washington to pass along to future generations the American tradition of a strong investment in scientific knowledge, and trust in the scientific method. And we should remind them that research spending is money in the bank, not money in a hole.

Mark Boslough

Mark Boslough is an impact physicist. After a 33-year career at Sandia National Laboratories, he is now affiliated with Los Alamos National Laboratory and is also an adjunct faculty member at the University of New Mexico. He is a Fellow of the Committee for Skeptical Inquiry.