In Finder, I have the "Install Xcode.app" file which is 1.81 GB. I told Finder to duplicate it, and it created a "Install Xcode copy.app" file that is only 1.57 GB. Why isn't the duplicate the same size as the original? Then I did a Get Info on the original, and it said the size is "1,814,588,172 bytes (1.81 GB on disk)". Then I did a Get Info on the duplicate, and it said the size is "1,570,347,315 bytes (1.81 GB on disk)". Why do both of them say "1.81 GB on disk" but then the number of bytes is different for each one? I am running Lion 10.7.2.