universes

 

Links:

http://www.pbs.org/wnet/hawking/strange/html/wormhole.html
http://www.bbc.co.uk/science/horizon/2001/parallelunitrans.shtml
http://casa.colorado.edu/~ajsh/schw.shtml
http://www.mkaku.org/
http://www.lifesci.sussex.ac.uk/home/John_Gribbin/timetrav.htm