In recent years, the definition of science has become an absolute jumbled mess. Scientists and non-scientists alike maintain that science needs to have a more central role in political decision-making. Meanwhile, scientists themselves argue over what constitutes science, either in an attempt to secure grant money for their own projects or to reform science education in a way they feel is more conducive to deep scientific understanding. To top that off, historic events like the building of the atomic bomb, the moon landing, and sequencing the human genome have progressively reformed the public’s understanding of what constitutes science and scientific progress. In the process, however, I think two major misconceptions about physics have creeped into the public consciousness. The first is that all good physics is either on the very very tiny (quantum and particle physics) or the extremely massive (astrophysics) scale. The second is that the scientific method is little more than simple hypothesis testing. Both of these misconceptions can have major repercussions for science as a whole, and it’s important that scientists and non-scientists alike come to appreciate the truth.
Ever since the first atomic bomb fell back in World War II, science (and especially physics) has been inextricably linked to the atom. Immediately after the war, governments all over the world stepped up their funding of research, particularly focusing on learning more and more about the fundamental particles that make up atoms. Since that time, the “indivisible” atom has been found to consist of smaller and smaller particles, from quarks and gluons to the Higgs Boson of recent fame. On the other end of the spectrum, ever since Sputnik first went into orbit, there’s been an obsession with space and the universe beyond our tiny little Earth. Recent advances in optics and telescopes have allowed us to observe things much further and much smaller than we ever could before, and the sales of books like “A Brief History of Time” show that the public is very interested in what might be out there. Given their visibility, one might assume that the frontiers of science lie either in the very big or the very small, and that everything in between has been thoroughly explored by every scientist since Newton.
There’s arisen a sort of hegemony in science, based on an assumed hierarchy of science, going from small to large. One might say that Biology is just applied Chemistry, which is itself just applied Many-Body Physics, which is little more than an extension of Particle Physics. By this logic, those who work in Particle Physics, discovering ever smaller particles, are the ones learning the real fundamental laws of the universe. Everything else trickles down from the understanding of particles.
But as a scientist whose research in Acoustics is decidedly on the order of human observation, I must say that’s not the case. In fact, there are many phenomena that we experience on a day-to-day basis that science can’t explain directly from particles physics. For example, turbulence isn’t well understood and is widely considered one of the open problems in physics. Yet, we hear turbulence when we drive a car with the windows open, and we feel turbulence when we’re flying in a plane. Despite seeing and hearing turbulence all the time, aside from using computational models to simulate it, we have no way to describe the underlying statistics of this phenomena in fluids. Richard Feynman, one of the darlings of science and a man with colossal physical and mathematical intuition, even tried to tackle this problem multiple times throughout his career to no avail. This is a man who, at the time, probably understood the inner workings of the atom better than anyone else on Earth.
So, is this a failing of Particle Physics? Not really. While the hierarchy of science does exist, there’s a hidden step between the levels that comes in the form of “complexity.” Anderson’s famous paper, “More is Different”, does a better job explaining this than I ever could. But the gist of it is this: if you have a bunch of objects, each working according to simple rules, the behavior of those objects as a population will follow rules that don’t necessarily resemble those of the objects as individuals. As an example, the simple behavior of a single ant (following chemical trails to food, picking up dirt and moving it, etc) doesn’t resemble the resulting ant colony, despite the former leading directly to the latter. An individual ant doesn’t have a rule that says that “You build a room in the colony for maturing larvae to grow in,” but the behaviors they do have still lead to this result.
With that in mind, it’s easy to see why particle physicists aren’t the ultimate scientists. By only understanding the lowest level of science, they can only really describe their level and perhaps the level directly above them. This is the case throughout the hierarchy. Molecular biologists need to understand chemistry to innovate within molecular biology, and they can offer insight into cell biology by understanding the level that sits directly below that. As an acoustician, I rely on solid state physics, fluid dynamics, chemistry, and thermodynamics to understand sound. Yet my understanding of acoustics does not give me mastery over linguistics, which relies on a combination of acoustics, physiology, psychology, and information theory.
Each sub-discipline of science has its own rules, derived from other disciplines, yet still unique. Understanding of these rules is the true goal of science, and every bit we learn can vastly improve the quality of life in both large and small ways. Hopefully I have shown you that there are still frontiers beyond particle physics and astrophysics. Next time, I’ll be talking about how biology and human genome have changed the face of scientific understanding and convinced people that all the scientific method can give us are yes/no answers.