Time machine

Meet the scientist trying to travel back in time

The past, it has been said, is a foreign country. And sometimes it's another country we yearn to visit.

We can't, of course. Whereas actual travel is limited only by how much cash we can spare, visa requirements and flight cancellations, journeying to times gone by is limited by the cold, hard laws of physics.

Or maybe it's not.

Joining the ranks of movie inventors like Doc Brown of "Back to the Future" are a few real-life scientists currently trying to realize the dream of turning back the clock to travel to the ultimate destination.

Among them is Ron Mallett, an astrophysicist who has dedicated much of his adult life to the notion that time travel is possible. He's come up with the scientific equations and principles upon which he says a time machine could be created.

While acknowledging that his theories and designs are unlikely to allow time travel in his lifetime, for years he's been working in parallel to a respected academic career to fulfill his dream of venturing back in time to see his beloved father again.