[dropcap]C[/dropcap]ould both gravity and the Big Bang be an illusion? In January 2010, Erik Verlinde, professor of Theoretical Physics and world-renowned string theorist, caused a worldwide stir with the publication of On the Origin of Gravity and the Laws of Newton, in which he challenged commonly held perceptions on gravity, going so far as to state ‘for me gravity doesn’t exist’. If he is proved correct, the consequences for our understanding of the universe and its origins in a Big Bang will be far-reaching.
“Everyone who is working on theoretical physics is trying to improve on Einstein,” says Robbert Dijkgraaf, UvA University Professor and current director of the Institute for Advanced Study in Princeton (where scientists including Turing, Oppenheimer and Einstein have worked) In my opinion, Erik Verlinde has found an important key for the next step forward.”
Verlinde, who received the Spinoza prize (the Dutch Nobel Prize) from the Netherlands Organisation for Science, is famous for developing this new theory, or idea, on gravity in which he says that gravity is an illusion. “Gravity is not an illusion in the sense that we know that things fall,” says Verline.” Most people, certainly in physics, think we can describe gravity perfectly adequately using Einstein’s General Relativity. But it now seems that we can also start from a microscopic formulation where there is no gravity to begin with, but you can derive it. This is called ‘emergence’.”
“We have other phenomena in Physics like this,” Verlinde continued. “Take a concept like ‘temperature’, for instance. We experience it every day. We can feel temperature. But, if you really think about the microscopic molecules, there’s no notion of temperature there. It’s something that has to do with the property of all molecules together; it’s like the average energy per molecule.”
To Verlinde, gravity is similar. It’s something that only appears when you put many things together at a microscopic scale and then you suddenly see that certain equations arise. “As scientists,” he observes, “we first want to understand nature and our universe. In doing so, we have observed things that are deeply puzzling, such as phenomena related to dark matter. We see things happening that we don’t understand. There must be more matter out there that we don’t see. There’s also something called ‘dark energy’. And then there’s the whole puzzle of the beginning of the universe. We now have what is called the ‘Big Bang’ theory.
Verline belives his ideas will shed new light on the concept of ‘dark matter’ and ‘dark energy’ and why they’re important in relation to gravity.
“We think we understand gravity in most situations,” he says “but when we look at galaxies and, on much larger scales, at galaxy clusters, we see things happening that we don’t understand using our familiar equations, like Newton’s equation of gravity or even Einstein’s gravity. So we have to assume there’s this mysterious form of matter, which we call dark matter, which we cannot see. Now dark