Optics: : [op-tiks] - noun. A branch of physics that studies electromagnetic radiation (for example, light and infrared radiation), its interactions with matter, and instruments used to gather information due to these interactions.Optics includes the study of sight. branch of physics that studies electromagnetic radiation (for example, light and infrared radiation), its interactions with matter, and instruments used to gather information due to these interactions.
By 1924, the National Flag Conference, under the leadership of the American Legion and the Daughters of the American Revolution, changed the Pledge's words, 'my Flag,' to 'the Flag of the United States of America.'
pledge. n. 1. A solemn binding promise to do, give, or refrain from doing something: signed a pledge never to reveal the secret; a pledge of money to a charity. 2. a. Something given or held as security to guarantee payment of a debt or fulfillment of an obligation.