Reloaded: Portal

: If you place a blue or orange portal in the present, it automatically appears in the same spot in the future. However, placing a portal in the future does not move its counterpart in the present.

: You can bring future versions of cubes back to the present, effectively allowing you to use two cubes to solve a puzzle, though you cannot take a present cube into the future. Content and Story PORTAL RELOADED - Full Walkthrough Portal Reloaded

: What you do in the present directly affects the future, but actions in the future do not change the past. : If you place a blue or orange