less than 1 minute read

Lock and Key

History, Modern Locks



A lock is a mechanical device for securing a door, chest, or other receptacle so that it can only be opened by an authorized person. Most locks are opened by a key which is placed in the lock and turned. Combination locks do not use a key but rather have a cylinder that is turned to certain stops. Today, many hotels use special plastic cards with magnetic strips as keys which cause a door to open electronically when inserted in a slot near the doorknob.




Additional topics

Science EncyclopediaScience & Philosophy: Linear expansivity to Macrocosm and microcosm