Complex sentence: He devised several different approaches to quantum gravity, in particular loop quantum gravity and advocates that the two primary approaches to quantum gravity, loop quantum gravity and string theory, can be reconciled as different aspects of the same underlying theory.
Split into simpler sentences: He devised several different approaches to quantum gravity, in particular loop quantum gravity. And advocates that the two primary approaches to quantum gravity, loop quantum gravity and string theory, can be reconciled as different aspects of the same underlying theory.