Professor of Physics at Harvard University, Nima Arkani-Hamed's research in theoretical physics is driven by attempting to address these mysteries. Much of his work has centered around addressing the hierarchy problem. He suggested that the extreme weakness of gravity can be attributed to the existence of large extra dimensions of space, perhaps as large as 100 microns in size, with the scale of quantum gravity lowered to the electroweak scale. This opens up the possibility that quantum gravitational effects can be probed at accelerators and even in table-top experiments. In a different direction he has constructed models where (non-gravitational) extra dimensions are generated dynamically from purely four-dimensional models.