ABSTRACT
Having come this far, you are ‚nally in position to appreciate the physics that needs to be in place if we are to construct a time machine. I have discussed Einstein’s two theories of relativity, both the special theory in which time and space are united into four-dimensional spacetime, and the general theory in which spacetime is then warped and twisted in the presence of matter and energy. Both theories are going to be needed in this chapter. I have discussed the nature of time and looked at the sort of problems that we must overcome if we insist on the possibility of time travel into the past. Now it’s pay-off time.
