A recent paper published by a Dutch physicist received a lot of scientific and media attention (“A Scientist Takes on Gravity”, The New York Times) for claiming gravity may not be a fundamental force. Instead, the author suggests it is merely another manifestation of the famous second law of thermodynamics, which says that things tend toward disorder. Or, in layman's terms, the planets orbit the sun and apples fall to the ground for roughly the same reason that milk tends to spill rather than unspill, and my desk tends to clutter rather than keep itself clean.
A new proposal says gravity may be an illusion. Right or wrong, the idea is a breath of fresh air for a field in need of new insights.
The details of the argument are interesting, and are best understood by further analogy. The essential idea is similar to that of diffusion. If you release a perfume into the air, it will slowly spread across the room, eventually filling the space. We can understand this as the result of the random motions of gas particles resulting in increasing disorder (the particles just go everywhere, which is a lot messier than perfume bottled up in a container). Or, if we weren't so clever, we might mistake this behavior as the result of some kind of repulsive force that causes perfume particles to push each other away. It may be that gravitational attraction is something like this. There are a few extra levels of abstraction to it, but that's the proposal in a nutshell: gravity isn't real.
But the details aren't what most interest me about the article. What does is the attention the article received. After all, this is theoretical physics we're talking about, a field where “crazy” ideas like parallel universes, teleportation, and extra dimensions are taken seriously, and where cats can be both dead and alive at the same time. Gravity isn't real, you say? Big deal.
But it is. Because, public perception notwithstanding, physics is a field that could use some new outside of the box ideas. Even the “curled up” extra dimensions implied by string theory, which sound so wild to most of us, have origins that are nearly one hundred years old, while the idea that vibrating strings may make up the matter around us actually dates back to the 1960's. What sounds strange and revolutionary to the layperson has become familiar and no longer useful to the theoretical physicist.
We need some deep thinkers to present us with new ways to think about the world, just like the patent clerk who, at the turn of the century, changed our views on space and time and ushered in a new era of physics and a new theory of gravity. This Dutch physicist, Erik Verlinde, who has also offered a new view of gravity, has received the attention he's received for giving us a truly novel idea. The attention is well deserved; we need more thinkers like him.
-blog authored by Andrew Loveridge