Here’s something we don’t often learn in school: To the great Isaac Newton, who gave us the laws of motion and of universal gravity (and much of optics too, and, of course, calculus), God was an active presence in the cosmos.
To Newton, God was not only the creator of the universe but also a sort of Cosmic Mechanic, who interfered every so often to ensure the stability of planetary orbits and the universe as a whole.
It was all related to gravity being an attractive force. Newton realized that the massive outer planets Jupiter and Saturn tugged at each other intensely. All was good, he realized, so long as nothing perturbed their orbits too much. But what would happen if a comet passed by too closely, nudging one of the two giants ever so gently? The end of our solar system and of Earth with it? Well, Newton would argue, the orbits are pretty stable. And if push came to shove, God would act to make sure all remained as stable as it should.
Same with stars. Newton conceived of an infinite universe, balanced somewhat precariously by having every star pulled by others in all directions. Again, if needed, God would prevent a massive collapse. To the father of modern physics, God was the creator and the protector of the cosmos.
In the 1700s and 1800s, science advanced away from Newton’s kind of God. The world became a mechanical machine, ruled by fundamental laws of nature. Energy and electric charges are conserved. The amount of rotation (angular momentum) is conserved. Momentum is conserved. Ben Franklin and others deemed God’s creator role as one with no direct intervention. The more science explained the world, the more invisible God became. Scientists, or natural philosophers as they were called, were people engaged in finding out the laws of nature, the essential rules that move the cosmos.
In the 20th century, very little of the old God talk remained in science. It was clear that to do science was to apply reason to nature and try to figure out how it operated. Yet, the God-designed cosmos remains, even if now more of a metaphor to most practicing scientists.
In his classic 1960s text The Feynman Lectures on Physics, the famous American physicist Richard Feynman made an interesting comparison between games and the laws of nature:
Imagine that the world is something like a great chess game being played by the gods, and we are observers of the game. We don’t know what the rules of the game are; all we are allowed to do is to watch the playing. Of course, if we watch long enough, we may eventually catch on to a few of the rules. The rules of the game are what we call fundamental physics.
According to this analogy, the laws of nature are like the rules of a game, and the physicist’s role is to figure them out. We do this by methodically observing what happens in the world, using our instruments and intuition in tandem with our deductive ability.
Feynman’s analogy illustrates several aspects of scientific thinking, the most obvious being our perennial blindness: what we see is only part of the whole story. Our worldview is by necessity incomplete. Whatever game the gods are playing, we can only perceive parts of it. The game of science is to improve our knowledge of this elusive game. And, as we do, the rules, at least some of them, also change.
For, say, Columbus in 1492, the cosmos was very different than for Newton in the late 17th century. In turn, Newton’s cosmos was very different from ours. To Columbus, the universe was finite, closed up like a sphere, with Earth fixed at the dead center of Creation. To Newton, the cosmos was infinite, ruled by mathematical laws. To find the laws of Nature was to read the mind of God, the Great Geometer. Today, we don’t know (and can’t know for certain) whether the universe is infinite or not; but we do know that it is expanding, the distances and speeds between galaxies growing.
The laws of nature are how we organize the regular patterns and behaviors that we can observe. Some are easy to identify, like the phases of the moon, the tides, or the seasons, all explained well with Newtonian physics. Others are harder to figure out, like the energy spectrum of the hydrogen atom or the precession of Mercury’s orbit or superconductivity.
If we continue with Feynman’s analogy, the gods play a very subtle game of chess, mixing visible and invisible moves. To see at least some of this invisible side of reality, we need to amplify our vision with special tools: telescopes, microscopes, mass spectrometers, particle accelerators, sensors and detectors of all kinds. Without tools of exploration, science is rendered useless. Or, as Feynman reminds us in the introduction to his book:
The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. Experiment is the sole judge of scientific “truth.” But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations—to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess.
New instruments have the potential to reveal new, often unexpected, laws. Sometimes, the novelty is revolutionary, and forces us to rethink some fundamental aspect of reality: the structure of space and time, the relationship between matter and energy, the properties of a star, the origin of the universe or of life.
Science is the sum total of our effort to figure things out, an ongoing process, always incomplete. The more we learn about the subtleties of this “god-like game,” the more we realize we have to learn. There is beauty in this blindness and how it feeds our appetite for more learning.
Who knows, maybe the laws form an infinite labyrinth, without beginning or end, and the best that we can do is catch glimpses of it here and there.