You have found this mysterious "stick of time" on earth. One of the TVA agents must have dropped it!
You are not one of those who likes to fool around, and decided to start cutting objects on your own.

Note: You can only crop one object at a time.
The objects will freeze in place to make the particles look right. 

------Management------

Press [P] to switch the particle effects.
Press [L] to cancel the cropping (the object that is being cropped will be deleted).