This article is part of DISCOVER's 30th anniversary special section, including 11 eminent scientists' predictions about the next 30 years. Share your thoughts on the future of science at the Science Not Fiction blog.
In the conventional picture of the origin of the universe, the Big Bang is the beginning of time. This is one of the greatest mysteries in science, and I’ve spent the last few years trying to work out how to make sense of the moment when, in that picture, the universe emerged from a point of infinite density and temperature—what’s known as the initial singularity. I’m exploring the idea that the singularity was not the beginning of time. In this new view, time didn’t have a beginning, and the Big Bang resulted from a collision of branes, sheetlike spaces that exist within a higher-dimensional reality. These collisions might happen repeatedly, creating an eternal, cyclic universe. We are now close to having the first mathematically and logically complete, consistent description of the passage of a universe through a singularity.
The exciting thing is that the observations to check these ideas could be done in the next 20 years, maybe even sooner. Currently, the most powerful data about the Big Bang are coming from the Planck satellite, which is mapping microwaves left over from the universe’s extremely hot early state. Planck can measure the temperature of those microwaves, looking for a particular pattern predicted by the standard model of cosmology. If we don’t see certain features of that pattern, that would be a blow against the standard model. Additionally, versions of our cyclic universe model make specific predictions about the distribution of different types of matter throughout the universe. For example, if we can observe the clustering of dark matter in the universe carefully enough, that might support the cyclic interpretation.
Regardless of who is right, it’s amazing that the science has reached the point where questions that used to be just philosophy could be observationally testable in only 10 or 20 years. We might even answer one of the most ancient and fundamental questions of all: Where did we come from? That would be profoundly satisfying. Some day we’ll move into space and start ensuring the survival of our species beyond Earth, whether it happens in a hundred years or a thousand. I don’t think it’s too far-fetched to imagine that a better understanding of how the universe works could help us with that in some way, by enabling us to exploit the basic laws of nature in developing new and unexpected technologies.
Cosmologist Neil Turok is the director of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, and founder of the African Institute for Mathematical Sciences in Cape Town, South Africa.