The electromagnetic spectrum is the total range of frequencies or wavelengths of electromagnetic radiationâ€”self-propagating waves of energy that result from the acceleration of electric charges. The spectrum ranges from waves of long wavelength, or low frequency, to those of short wavelength, or high frequency, and includes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. In a vacuum, these waves all travel at what speed?
Bright and confident and true,
And the old love comes to meet me, in the dawning and the dew.
Robert Louis Stevenson
Back in the day
CNN, a division of the Turner Broadcasting System owned by Time Warner, is widely credited with introducing the concept of 24-hour news coverage. Its services are available to more than 1.5 billion people in over 212 countries and territories. CNN's coverage of the Gulf War and other conflicts and crises of the early 1990s, including, perhaps most famously, the "Black Hawk Down" incident in Mogadishu, led to the coining of the term "the CNN effect." What phenomenon does the phrase describe?
Born on a day like today
Young was an early leader of the Church of Jesus Christ of Latter-Day Saints, or Mormon Church, who helped maintain the unity of the church after Joseph Smith, the founder of Mormonism, was assassinated in 1844. He led the great migration west and established a settlement at Salt Lake City, where the Church is headquartered today. He defended Mormon interests during the Utah War, eventually losing his post as governor of Utah. A known polygamist, Young had how many wives and children?