00710cgm a2200169Ia 4500050000800000245005300008260008200061300004500143490003300188500008100221520013400302650002500436650002000461700002300481700001600504700002000520 4aQC600aAt the frontierbyoung people and climate change  aBerkeley, Calif. :bUniversity of California, Extension Media Center,cc2009.  a1 videocassette (30 min.) :bsd., col. ;1 aUnderstanding space and time  aProduced for the Open University and the University of California by BBC-TV.  aDiscusses current experimental testing of Einstein's general theory being carried out around the world as well as in outer space. 0aRelativity (Physics) 0aSpace and time.1 aSchwinger, Julian,1 aSolomon, A.1 aCrilly, Andrew.