Posted on May 18, 2009December 30, 2011 by WalterEverything Everything depends on how the system is defined, and this in turn depends on who is the observer. (DC 274, 346) gwu.edu Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to email a link to a friend (Opens in new window)Like this:Like Loading... Related