(Image: Lucio Martus/EyeEm/Getty)
AH, BUT does it? For anyone versed in modern theoretical physics, that’s not such a silly question. “I don’t know any mathematical reason why three-dimensional space is more consistent than any other number,” says of Stanford University in California.
Susskind is one of the founders of string theory, which is our best stab yet at a unified understanding of physics – and perhaps the best-known model in which extra dimensions are found. One of string theory’s peculiar features is that when applied to fewer than nine spatial dimensions, the mathematics goes wild, predicting violent fluctuations that rip apart the very fabric of the universe.
But extra dimensions do more than just save string theory’s blushes. In a wider set of theories, gravity leaking into a higher space could explain why in our three dimensions it is so weak compared with the other fundamental forces, and why the expansion of the universe is apparently accelerating.
So perhaps the question becomes: why does space have three visible dimensions?
One idea from string theory is that . Or perhaps our 3D universe exists on one of many “branes”, membrane-like entities that float around in a larger, higher-dimensional space.
of Harvard University and Andreas Karch of the University of Washington in Seattle have shown that branes colliding in such a space would tend to form 3D branes – an explanation of sorts…
