I hate gravity. Oh, it has its uses, like keeping my morning coffee in the cup and holding down all the files of scientific articles stacked up in my office. But it also consistently causes me unnecessary aggravation. I open the freezer door and the ice cream slips out and heads toward my toes. If I stand two rolling suitcase bags next to each other, one will invariably fall and knock the other over. When I bend over to pick up the bags, my glasses fall on the floor. If I pile up my collection of CDs, they will not be in a neat stack when I return.
Gravity does not discriminate, nor does it take vacations. It is relentless. Gravity is an opportunistic predator that takes advantage of small deviations from level to bring any object down to the lowest level of potential energy—usually the floor. Most adults courageously fight the good fight against gravity every day. Teenagers, on the other hand, have not yet taken up the struggle and live in relative harmony with gravity—especially in their bedrooms. Everything just automatically goes on the floor, giving gravity nothing more to do.
Perhaps teenagers intuitively sense something that some theoretical physicists are now considering: could gravity really be just a grand illusion? In a recent Scientific American article, former Harvard University physicist Juan Maldacena says one of the three dimensions of space—height, width, or length—might be an illusion created by particles moving in just two dimensions, and that gravity, too, “would be part of the illusion.”1 Maldacena uses the example of a holographic image which appears to be three-dimensional, even though it is physically a two-dimensional object. In a holographic image, depth is an illusion.
Illusions are fine in holographs and the world of the theoretical physicist, but we live in a world where gravity and its effects are very real. For decades there has been a growing gap between science based on observable, repeatable events and experiments, and the non-testable theories of virtual universes and dimensions of the theoretical physicist. Without the requirement for experimental verification, speculation and theory too often become fact by simple assertion. For example, Maldacena asserts that, in the quantum view of the world, everything is in flux. Even so-called empty space, “which is, in fact, filled with virtual particles that perpetually pop in and out of existence,” is not really empty.1 Theoretical physicists have come to accept theory as fact and have, in turn, encouraged the general public to regard verifiable facts as a grand illusion. As much as I might wish gravity were an illusion, I am not persuaded to believe that it is so by pseudo-scientific assertions of what “might” be based on quantum physics. No, the evidence that gravity is not an illusion is too easily found in my teenager’s room, where I can’t see, let alone walk on, the bedroom floor.
1 J. Maldacena, “The Illusion of Gravity,” Scientific American, November 2005, 56-63.