On Monday, hundreds of millions of Americans will take a two-hour break to watch something that hasn’t happened in 99 years: a total solar eclipse. For those who don’t remember their primary education days and have missed the various bits of news coverage on it, the moon will pass between the Earth and the sun during daylight hours. Fourteen states in the U.S. will have the pleasure of seeing a total eclipse of the sun; in other words, the sun being fully blotted out by the moon for a few moments (though the build-up will be several hours long).