George F. Smoot Cosmologist, Lawrence Berkeley National Laboratory; Recipient, The Nobel Prize For Physics 2006; Coauthor, Wrinkles in Time
This is a map of the space-time for our observable universe. It shows two of three spatial dimensions and the time.
It shows the beginning of time to the present epoch. You have to imagine the third spatial dimension as the continuation of the sphere of space around us for which the two dimensions show a circular cross section.