book was written, for its hospitality. The Institute, where Einstein spent the last decades of his life, was an appropriate place to write about the revolutionary developments that have extended and embellished much of his pioneering work.
PART I
Entering
the Fifth Dimension
But the creative principle resides in mathematics. In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.
Albert Einstein
I
Worlds Beyond Space
and Time
I want to know how God created this world. I am not interested in this or that phenomenon. I want to know His thoughts, the rest are details.
Albert Einstein
The Education of a Physicist
TWO incidents from my childhood greatly enriched my understanding of the world and sent me on course to become a theoretical physicist.
I remember that my parents would sometimes take me to visit the famous Japanese Tea Garden in San Francisco. One of my happiest childhood memories is of crouching next to the pond, mesmerized by the brilliantly colored carp swimming slowly beneath the water lilies.
In these quiet moments, I felt free to let my imagination wander; I would ask myself silly questions that a only child might ask, such as how the carp in that pond would view the world around them. I thought, What a strange world theirs must be!
Living their entire lives in the shallow pond, the carp would believe that their “universe” consisted of the murky water and the lilies. Spending most of their time foraging on the bottom of the pond, they would be only dimly aware that an alien world could exist above the surface.The nature of my world was beyond their comprehension. I was intrigued that I could sit only a few inches from the carp, yet be separated from them by an immense chasm. The carp and I spent our lives in two distinct universes, never entering each other’s world, yet were separated by only the thinnest barrier, the water’s surface.
I once imagined that there may be carp “scientists” living among the fish. They would, I thought, scoff at any fish who proposed that a parallel world could exist just above the lilies. To a carp “scientist,” the only things that were real were what the fish could see or touch. The pond was everything. An unseen world beyond the pond made no scientific sense.
Once I was caught in a rainstorm. I noticed that the pond’s surface was bombarded by thousands of tiny raindrops. The pond’s surface became turbulent, and the water lilies were being pushed in all directions by water waves. Taking shelter from the wind and the rain, I wondered how all this appeared to the carp. To them, the water lilies would appear to be moving around by themselves, without anything pushing them. Since the water they lived in would appear invisible, much like the air and space around us, they would be baffled that the water lilies could move around by themselves.
Their “scientists,” I imagined, would concoct a clever invention called a “force” in order to hide their ignorance. Unable to comprehend that there could be waves on the unseen surface, they would conclude that lilies could move without being touched because a mysterious, invisible entity called a force acted between them. They might give this illusion impressive, lofty names (such as action-at-a-distance, or the ability of the lilies to move without anything touching them).
Once I imagined what would happen if I reached down and lifted one of the carp “scientists” out of the pond. Before I threw him back into the water, he might wiggle furiously as I examined him. I wondered how this would appear to the rest of the carp. To them, it would be a truly unsettling event. They would first notice that one of their “scientists” had disappeared from their universe. Simply vanished, without leaving a trace. Wherever they would look, there would be no evidence of the missing carp in their universe. Then, seconds later, when I threw him back into
David Sherman & Dan Cragg