Arkani-Hamed is only in his mid-30s, but he has already distinguished himself as one of the leading thinkers in the field of particle physics.
His revolutionary ideas about the way the universe works will finally be put to the test later this year at Switzerland's Large Hadron Collider, which, when completed, will be the world's most powerful particle accelerator.
A theory that has emerged in recent decades that claims to bring some relief to physics mysteries like these is called superstring theory, or string theory for short. While previously, scientists believed that the smallest, most indivisible building blocks of our world were particles, string theory says that the world is made of extremely small vibrating loops called strings.
In order for these strings to properly constitute our universe, they must vibrate in 11 dimensions, scientists say. Everyone observes three spatial dimensions and one for time, but theoretical models suggest at least seven others that we do not see.
Arkani-Hamed proposed, along with physicists Savas Dimopoulos and Gia Dvali, that some of these dimensions are larger than previously thought -- specifically, as large as a millimeter. Physicists call this the ADD model, after the first initials of the authors' last names. We haven't seen these extra dimensions yet because gravity is the only force that can wander around them, Arkani-Hamed said.
String theory has come under attack because some say it can never be tested -- the strings are supposed to be smaller than any particle ever detected, after all. But Arkani-Hamed says the Large Hadron Collider could potentially lead to the direct observation of strings, or at least indirect evidence of their existence.