When most people think of the greatest scientific developments of the 20th century they think of developments that happened between 1905 and 1925, when special and general relativity were developed, as well as quantum mechanics. But in fact, another 20 year period, between 1955 and 1975 may be remembered in the far future as by far the most productive period in physics in that century. We began that period understanding one of the four forces in nature in a way consistent with quantum mechanics, and by the end of that period we understood 3 of the 4 fundamental forces completely, and our thinking about the fundamental symmetries of nature even affected the way we think about the odd man out today: gravity.
Beyond this, we now understand that the universe we experience is really in many ways an illusion. The fundamental laws, and even the fundamental nature of the forces that govern our existence, are quite different than those that we experience. In many ways our existence is a cosmic accident, and certain features about the universe we take for granted, like the long-range nature of electromagnetism and the consequent conservation of electric charge, and even the existence of mass itself, are accidents of our circumstances. We are like beings living on an ice crystal that is part of a beautiful pattern on a windowpane in the winter. For them, the features of their universe, including the fact that one direction—the direction along the spine of the crystal—would appear very special would be taken for granted as a general feature of the laws of nature. But that would be myopic. And if the crystal were to melt on a sunny morning, that feature would disappear (as, likely, would they). Our Universe parallels this analogy very closely.
The long search to discover these hidden realities reflects the best of what it means to be human—a brave effort over hundreds of years to overcome natural biases and adversity to free our minds from our cosmic myopia, combined with a willingness to bring together thousands of scientists, from over 100 countries, speaking dozens of languages, for the single purpose of trying to understand why we are here.. or rather how everything we see in the universe arose. I call this the Greatest Story Ever Told… So Far, because not only does the story have all the drama of an epic poem like the Odyssey, but the story is not complete. The best is likely yet to come.
This reflects the fundamental, and wonderful, feature of science that our understanding of nature evolves with the knowledge we gain from experiment. It isn’t fixed, like ancient iron-age myths that make up the sacred books of all the world’s major religions. The willingness to be wrong, to be surprised, and to discover that we are not the center of the universe—ultimately to agree to force our beliefs to conform to the evidence of reality rather than vice-versa—is what characterizes the scientific enterprise, and is what has helped make it so successful.
While the story behind the development of the Standard Model of particle physics is at times esoteric, it is a story that addresses at its heart the very questions most people have about the universe: How did we get here? How did all the structure we see arise? What will the future bring?. Moreover, by understanding how science cut through illusion and myopia in our understanding of nature we get an example of the other utility of science—its utility for helping us design public policy that actually works.
In these times of ‘alternative facts’ and political illusions, science provides not just a set of facts, which is unfortunately how science is too often taught in schools, but rather a process by which we arrive at facts, by which we tell sense from nonsense. That process is of vital importance today for the health of democracy. An informed public—one that is able to tell nonsense from sense—is vital to the functioning of democracy, and legislators who are also willing to have their policies guided by empirical reality, and not bias and prejudice are also necessary. By exploring the history of human inquiry, focusing on humanity at its best, and heralding the greatest intellectual journey humans have ever undertaken, we can gain a perspective on our current understanding of our place in the Universe and also a guide for how to overcome myth and superstition in our current world. In this sense, I continue to view science, like art, music, and literature, as a vital part of our culture, something that changes the way we think about ourselves, and that lifts us up to make the world a better place.
As I put it in my recent book:
“Faced with the mystery of our existence we have two choices. We can assume we have special significance and that somehow the Universe is made for us. For many, this is the most comfortable choice. It was the choice made by early human tribes, who anthropomorphized nature because it provided them some hope of understanding what otherwise seemed to be a hostile world often centered on suffering and death. It is the choice made by almost all the world’s religions, each of which has its own solution to the quandary of existence.
… The second choice when addressing these transcendental mysteries is to make no assumption in advance about the answer. This leads to another story. One that I think is far more humble. In this story, we evolve in a Universe whose laws exist independently of our own being. In this story we check the details to see if they might be wrong. In this story we are surprised at almost every turn…”
Lawrence M. Krauss, a theoretical physicist, is Director of the Origins Project at Arizona State University, and the author, most recently, of The Greatest Story Ever Told.. So Far.