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.'
A pledge is basically very serious formal promise. You can pledge allegiance to your country, you can pledge to keep a secret, and you can pledge a sum of money to a cause. Pledge can be used as both a noun and a verb. As a noun, it can be a solemn promise you've made. Or even the person who makes that promise, like the freshman pledges who take an oath to join a fraternity in college. As a verb, it describes the act of promising.