Michio Kaku on time travel and parallel universes

We are all, in fact, travelling through time at the speed of light. Only by moving about (ie travelling through space) can we decrease the speed of our progress through time. So stay in your chair and enjoy the ride.

travelling through time at the speed of light". How so, HighVoltage ?

Think of a graph with the Y axis pointing in the direction of time and the X axis pointing in the direction of space. You are moving as fast as is possible (i.e. C or what we know as the speed of light) in a vertical line along the Y (time) axis because there is no frame of reference (relativity). If you start to move along the X axis (i.e. move in space) then you begin to deviate from the Y axis and your 'trajectory' on the graph starts to become more diagonal, with the result that you begin to move more slowly through time the faster you move through space. The result is that at least one way of describing this situation is that we are "moving at the speed of light" while at rest.

Baah. I want a time machine

that'd be awesome... too bad we're gonna be dead by the time some of these theoretical inventions exist

It's weird, what would happen if they went back and time and say us alive?