A place for random thoughts - space and time

In his latest book The Fabric of the Cosmos, Brian Greene explains the current scientific conception of time and space. Most of us assume that the nature of time and space was settled some time ago, but for physicists it is still an open question. Adherents to superstring theory, for example, suggest that there may be as many as eleven dimensions rather than three.

Space and time form the very fabric of the cosmos. Yet they remain among the most mysterious of concepts. Is space an entity? Why does time have a direction? Could the universe exist without space and time? Can we travel to the past? Greene establishes that nothing in the laws of physics insists that it run in any particular direction and that “time’s arrow” is a relic of the universe’s condition at the moment of the big bang. Greene shows how recent cutting-edge developments in superstring and M-theory may reconcile the behavior of everything from the smallest particle to the largest black hole. This startling vision culminates in a vibrant eleven-dimensional “multiverse,” pulsating with ever-changing textures, where space and time themselves may dissolve into subtler, more fundamental entities.

As a child, Brian Greene used to play a game with his father as they walked the streets of Manhattan. They would observe something going on around them, a bus driving by, a pigeon landing on a windowsill or a man accidentally dropping a coin and try to imagine what the event would look like from another perspective. As the coin flipped its way to the ground for example, it would witness a revolving blur of sky, buildings, pavement buildings and sky again.