Although the scientific questions of our age and of all ages do not touch the central truth of the Christian Gospel: “that God was in Christ, reconciling the world unto himself,” we must nevertheless recognize the fact that the changes which have occurred in our ideas concerning the universe have resulted in changes in our thought of God and of his revelation to man as well. One of the most beautiful and significant of all such scientific contributions is the concept that the entire universe is one in origin and essence, that through all the seeming chaos of phenomena runs one all-pervading, all-controlling system of law.
One might suspect that men could have learned this lesson solely from a study or the Holy Scriptures. The fact of the matter is, however, that this concept did not come to its full fruition until Newton discovered the law of gravitation a few centuries ago. Before Newton’s time the popular conception of the universe was largely poetic and mythological. That age which regarded sunbeams as the golden arrows of Apollo, seems far removed from our age which measures wavelengths and counts the vibrations of light. Yet it is precisely this cold, methodical scientific age which has been used to provide the data for a more beautiful conception of the universe and of its Creator.
It is easy to understand why polytheism, that is, the belief in many gods, flourished in times past. The processes of nature seemed to result from independent agencies which were diverse, antagonistic forces. Polytheism is the natural counterpart of the unscientific view of nature. If there are several, independent forces operating in the universe, it seems plausible for those lacking special light to regard each of these forces as a deity entitled to some kind of homage. Small wonder that the Greeks established an altar also “to the unknown god” to make certain they had not forgotten anyone of the many gods they felt obligated to worship.
The Hebrews were unlike the nations round about them since their faith was in the “one Jehovah” (Deuteronomy 6:4). Although the Bible revealed to them that all nature was the work of one creator, they never attained to any such conception of the unity of nature as modern science has developed. When the contributions of modern science are viewed in the light of God’s revelation in Scripture we gain a nobler conception of God than was ever possible centuries ago. Although the Psalmist was moved to write “the heavens declare the glory of God and the firmament showeth his handiwork,” the full implications of this passage were not understood until Newton discovered the law of gravitation. We who understand the various aspects of this law can appreciate why Newton was moved to write, “This most beautiful system of the sun, planets and comets could only proceed from the counsel and dominion of an intelligent and powerful being…He governs all things and knows all things that are or can be done.”
And to an age which imagined the stars as being only a few hundred feet up in the sky (which seemed far away to them), the passage “As far as the heavens are above the earth, so far hath he removed our transgressions from us” could not have the significance it has for us who have learned to measure these distances in terms of millions of light-years. One cannot help wondering at times, however, if our lives actually manifest a greater appreciation of this marvelous love of God than that shown by some of the saints of old. Has the development of spiritual life kept apace with that of the discoveries in the physical realm?
Unity and the Law of Gravity
There are several discoveries in the field of science which have aided in developing the concept of the unity of the universe. Robert Mayer’s discovery of the law of conservation of energy, Albert Einstein’s prediction that matter and energy are equivalent and interconvertible, and Newton’s discovery of the universal law of gravitation are only three of the many which can be cited. We shall discuss the latter, not merely because it happens to be the easiest to explain, but because it is possibly the most basic. It is of such great importance that the mathematician Laplace, a contemporary of Newton, was moved to say concerning him, “Newton was the greatest genius who ever lived, and the most fortunate, for there cannot be more than once a system of the world to establish.” One part of this law states that every particle of matter in the universe is attracted to every other particle. At first glance this may not seem to be at all a striking statement. But it implies that not only is the apple attracted to the earth but also that the apple pulls on the earth. This force of attraction is very smalL Krauskopf in his Fundamentals of Physical Science states that two 40,000-ton oceanliners attract each other with a force of about half an ounce when placed a half mile apart. When we speak of the force of gravity we do not limit this to the attraction which the earth has for an object. Rather every object in the universe is attracted to every other object by the same kind of force.
Although such a concept is important it does not satisfy the scientist any more than the reader would be content with knowing that he could buy some oranges for his money. We all want to know exactly how many oranges we can get for a given amount of money, that is, we want an equation which relates the amount of money to the number o.f oranges. If we know the price of one orange we can readily calculate the number obtainable for a dollar. We also know that we can buy twice as many (or two dollars, providing the price remains the same.
The scientist must know the same type of number when he attempts to state his laws. He knows that all particles o( matter in the universe are attracted to each other, that this force is greater for large objects than for small ones, and also that this force becomes weaker as the objects are moved away from each other. But we still do not know exactly how great these forces are on the basis of this statement alone. vVe must find something comparable to the price of one orange in order to know something about a larger number of oranges. Such a number which gives a quantitative relationship between conditions is called a proportionality constant in mathematical language.
System of Measurement
The need for such constants has long been recognized and resulted in the adoption of a system of units of measurement many years ago. Any system can be used provided everyone plays the game according to the same rules. If the system varies in different countries it is still possible to change from one system to another. This point can be illustrated by comparing the different monetary systems which are in use. If oranges cost five cents each we can easily figure out how many we can get for one dollar. But we can also buy oranges if we have British pounds or Dutch guilders provided we know the rate of exchange. The rate of exchange between any two units relates one system to the other. If somehow we could measure the amount of force which two one gram masses exert on each other when placed one centimeter apart we would know “the price of one orange” for one system of measurement. If we were to use ounces and inches in place of grams and centimeters we would obtain a different number. However, these two numbers would always have the same relation to each other no matter how much of each object we have even as a constant relation exists between dollars and guilders.
A description of the experiment by which this constant can be determined need not concern us here. Suffice to say that it can and has been done in more than one way. But we should point out that we are limited in our measurement of this constant to the use of objects on our earth and relatively minute objects at that. What right, then, has a scientist to say that all the matter in the universe is governed by this one law of attraction? We can show that it is true for all bodies on the earth, but what assurance do we have that the value of this gravitational constant—this price per orange—is the same for the sun or moon as it is for the earth? Man cannot set up a laboratory there to prove it. Yet we calculate the masses of these bodies on the basis that this constant is valid for all bodies. And how can we be certain that the constant does not depend on the composition of the object, that only the masses of the objects and the distances separating them are significant?
Our Solar System In order to answer these questions we must first mention a few facts about the solar system. The sun is the dominant member of our solar system. Revolving around it are nine major bodies called planets. These vary in size, density—which implies variations in composition—and in their distances from the sun. In addition to these there are countless smaller bodies in the solar system, called planetoids, which vary in size from a few miles to five hundred miles in diameter. These bodies are relatively unimportant. The stars lie beyond the planets, the closest one to the earth being Alpha Centauri which is 4.3 light-years away.
The existence of some of the planets has been known for centuries. The ancient Babylonians recognized the existence of five of them as early as 3000 B.C. The word planet is derived from the Greek for “wanderer” and the ancients were able to discover some of them since their positions in the heavens change with respect to the stars. In conformity with the practice of the day, they were assigned names in honor of the Roman deities. Obviously, the ancients knew only the five planets which can readily be seen with the unaided eye. They recognized Mercury, Venus, Mars, Jupiter, and Saturn. These are listed in the order of their increasing distances from the sun. The earth, although also a planet, was not recognized as such until after the heliocentric Copernican theory had been announced. The moon is not a planet. It is a satellite of the earth, that is, a body which revolves around the earth. Jupiter, for example, has eleven such satellites, four of which were discovered by Galileo. The three remaining planets, Uranus, Neptune, and Pluto, which concern us at this point, were discovered by means of the telescope.
The fact that Uranus is a planet was discovered accidentally in 1781 by Sir William Herschel. While studying the constellations with his homemade telescope he noticed an object having a disk. His curiosity was aroused since stars do not have these. A search of the records indicated that this body had been discovered about a century earlier and was classified as a star. Herschel thought, at first, that he had discovered a comet but when he calculated the orbit of this new body, that is, the path which a body follows in its travel around the sun, he was forced to conclude that it was a planet.
The orbit of a planet can be determined [rom observations of several of its apparent positions over a period of time. Predictions are then made concerning its future positions and motions in the same way that ·eclipses are predicted in advance. Everyone has some knowledge concerning the high degree of accuracy of such predictions. For about the first fifty years after its discovery no .discrepancy was noticed between the calculated and observed paths of Uranus. During the next twenty years it was noticed that the planet .deviated slightly from its calculated orbit. Since the orbit of a planet can be determined with a high degree of accuracy, the slightest deviation from the prescribed path causes astronomers to question the validity of their calculations. One of the possibilities which presented itself in connection with the deviation from the prescribed path for Uranus was that the constant for Newton’s law of gravitation might not be quite accurate for objects at such a large distance from the sun. This, obviously was a possibility that scientists hated to consider. The other possibility was that some unknown planet, moving in accordance with the law of gravitation, was pulling Uranus away from its predicted path.
It so happened that two mathematical astronomers were convinced that the law of gravitation had universal validity and that the motion of Uranus could be explained on the basis of some still unknown planet. Neither one knew that the other was working on the problem and, since both of them reached practically the same conclusion at about the same time, the two are given credit for making the discovery. J.C. Adams of Cambridge, England, was the first to complete the necessary calculations. He sent his material to England’s Astronomer Royal in 1845, who shelved the material for the time being due to lack of interest and the complexity of the problem. The other man working on the problem, U.J. Le Verrier of Paris, France, completed his work a year later and also submitted it to the Astronomer Royal.
Some interest was now shown in the prediction that a planet must exist beyond Uranus and that the mutual attraction of the two for each other caused the variation in the motion of Uranus. If we believe some of the stories concerning him, it is evident that Le Verrier was a queer type of individual. The French astronomer Flammarion relates that he invited Le Verrier to look at the newly discovered planet, which was named Neptune, on one occasion and Le Verrier replied that he had never seen it and never wan ted to see it. He was completely satisfied to have calculated that such a body existed. Beyond that he had no interest in the matter.
It is readily understandable that a man with such a disposition would have very little patience with anyone who did not immediately attack a problem of real concern to him. This was Le Verrier’s reaction to the attitude of the British astronomers. He wanted action on his work and thus it came about that he sent a copy of it to a young German astronomer, named Galle, who was well qualified to do the work. He discovered the new planet within half an hour after beginning his search and at practically the same position as the one predicted for it.
It should be pointed out in fairness to the Astronomer Royal that Galle had an advantage in that he had just completed a study of the stars in the section of the sky where Neptune was discovered. The reader should not get the idea that it is a simple matter to train a telescope on a portion of the heavens and pick out a hitherto unknown body. The lesson to be learned from this incident is that a scientist who believes that he has proved or discovered some fact should not wait too long to verify his conclusions and publicize them. The above occurrence is not an isolated event in the history of science, as several scientists can testify. Naturally, the other extreme has also occurred and some scientists run headlong into print on the slightest provocation.
The Universality of Newton’s Law
The real significance of this work lies in the fact that it proved that Newton’s law of gravitation can be applied to all objects in the universe, even though they may be separated by billions of miles. The constant of the law of gravitation, although measured in terms of matter on the earth, is the same for all matter in the universe. The elements composing the other heavenly bodies are identical with those we know on the earth. The fundamental building blocks are the same throughout the entire universe. It is logical to conclude that all matter, then, has a common origin, an origin which the Christian finds in God. It also follows that a polytheism which enthroned Mars as the god of war, Venus as the goddess of love and beauty, had no chance of survival in the light of such discoveries. All matter is the same and the elements of the inorganic world owe their origin to the same Creator who fashioned our bodies out of the dust and breathed into them the spirit of life.
Some may lament the fact that many of the former mystical explanations of natural phenomena have disappeared and we now explain these in cold, scientific language. vVe feel. however, that the concept of God which results from the new explanations is a far loftier one than that of the ancients. It is unfortunate that a mechanistic view of nature, that is, a view which explains all nature solely on the basis of Newton’s laws of gravitation and motion, was developed by those who used these laws to explain the universe in terms other than that of a Creator-God. But this is not the fault of Newton.
The Christian believes that understanding nature means more than reducing it to the laws of Newtonian mechanics. He admires, even more so than does the mechanist, the wonderful unity and harmony in nature but relates it to the Creator. Although he appreciates the discoveries which have been made in the realm of nature, he is always conscious of the fact that God established the unity underlying all of it. We believe that the development of this most important of all the characteristic ideas of science, namely, the idea of the unity of the universe, is the real significance of the contribution of Newton’s work. Men had little justification for such a belief previous to the discovery of the law of gravitation. The universe which science has unfolded for us is an order!y, God-created one rather than a capricious, mystical one.
It should be noted in conclusion that Albert Einstein takes issue with Newton’s laws of gravitation and motion. He does this since the motion of the planet Mercury, which is small and very close to the ;un, is not the same as that predicted for it on the basis of Newton’s theory. The rapidity with which it moves and its proximity to the larger body should not affect its gravitational force, if Newton’s law is absolutely true. Einstein’s explanation for the eccentricity of its orbit is too mathematical for us to consider here. Suffice to say that he is able to do so on the basis of non-Euclidean geometry.
In spite of this, gravitation is still one of the greatest mysteries in the universe. We do not know the relation which this simple, everyday experience has to the ultimate structure of the entire creation, whether the objects be large or infinitely small. We do not know why it remains constant under all circumstances or whether it is absolutely instantaneous in its action. Yet on the basis of a large number and variety of experiments, scientists have concluded that the law of gravitation is the broadest and most fundamental one which man has discovered to date. And although Einstein’s theory of gravitation may some day give us a more accurate picture of the universe than that given to us on the basis of Newton’s law, the refinement of the law which he contributes does not invalidate the principle of the unity in the universe. On the contrary, it gives added support to it.