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 noun [C]. âº a âserious or âformal âpromise, âespecially one to give âmoney or to be a âfriend, or something that you give as a âsign that you will âkeep a âpromise: [+ to infinitive] All the âcandidates have given/made pledges not to âraise âtaxes if they are âelected.