Brian Greene — American Physicist born on February 09, 1963,

Brian Randolph Greene is an American theoretical physicist and string theorist. He has been a professor at Columbia University since 1996 and chairman of the World Science Festival since co-founding it in 2008. Greene has worked on mirror symmetry, relating two different Calabi–Yau manifolds. He also described the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point... (wikipedia)

The boldness of asking deep questions may require unforeseen flexibility if we are to accept the answers.
The tantalizing discomfort of perplexity is what inspires otherwise ordinary men and women to extraordinary feats of ingenuity and creativity; nothing quite focuses the mind like dissonant details awaiting harmonious resolution.
As every parent knows, children begin life as uninhibited, unabashed explorers of the unknown. From the time we can walk and talk, we want to know what things are and how they work - we begin life as little scientists.
String theory has the potential to show that all of the wondrous happenings in the universe - from the frantic dance of subatomic quarks to the stately waltz of orbiting binary stars; from the primordial fireball of the big bang to the majestic swirl of heavenly galaxies - are reflections of one, grand physical principle, one master equation.
The bottom line is that time travel is allowed by the laws of physics.