If you want to build a star, start with the rules. That is the advice I give to my Ph.D. students at the University of Rochester. Using advanced supercomputers and programming, we simulate the complex interplay of gravity, radiation, and magnetic fields that constitutes the life of stars like the sun. Our goal is to better understand how stars are born, grow old, and die. Fundamentally, we start with the known laws of physics and take them wherever they lead us. The implicit understanding is that nature’s rules are eternal, unbreakable, and all-controlling. As Albert Einstein once said, learning to read the laws of physics is like reading the mind of God.
Such thinking has animated much of the enterprise of physics ever since Isaac Newton formulated his laws of universal gravitation in 1687: one set of laws for both the heavens and the earth. The idea took full root a century ago, when Einstein developed his general theory of relativity. If we work hard enough, he suggested, we will eventually find the elegant and simple rules that undergird the entire universe. Physicists have taken it as an article of faith that the bedrock laws are there to be discovered, if only we are clever enough in looking for them. The dogged pursuit of that ultimate truth has led to many great discoveries, but recently it has begun to seem like a promise unkept.
The problem is that physics appears to be leading us not to resolution but into an Alice in Wonderland world of increasingly bizarre theories, each farther removed than the last from our experience of the everyday world. In recent years cosmologists have posited that our universe is just one among an untold number of universes that bubble up constantly from quantum foam. Theoretical physicists have looked to the exotic mathematics of string theory, which suggests the existence of seven extra dimensions beyond the four we already know about. Experimentalists have built the $10 billion Large Hadron Collider in part to understand why we can observe only a portion of what our theories of matter predict.
If scientists have to dream up dimensions that nobody has ever seen and universes that nobody may ever find, perhaps it is a sign that we are headed down a blind alley. If we are indeed getting closer to knowing nature’s immutable laws, a few renegade physicists are now asking, why does each step we take only seem to send us deeper into the rabbit hole?
The mainstream response is that this is how science works. Each answer is supposed to yield new questions. Most physicists, to be sure, are still holding out for an elegant unifying vision—the long-promised “theory of everything”—and they are prepared to wait the 50 years or so it might take to arrive at one. The dissenters, though, are starting to wonder about this approach. If we have to take so much on faith, aren’t we behaving more like priests than like scientists? Perhaps, argue the rebels, our basic assumptions are leading us astray. Perhaps those immutable laws that we have been pursuing all these years are not so immutable after all. Could it be that we have taken for granted the existence of something fundamental, the way early scientists took for granted the existence of God?
