Why Does Time Go Forward?

Photo Credit: UnknownNet Photography via Compfight cc

If time travel is possible, where are the tourists from the future?

~STEPHEN HAWKING, author of A Brief History of Time

How did the universe begin—and what made its start possible? Does time always flow forward? Is the universe unending—or are there boundaries? Are there other dimensions in space? What will happen when it all ends?

A Brief History of Time plunges into the exotic realms of black holesand quarks, of antimatter and “arrows of tim...