Mark Twain (Wikipedia)
Samuel Langhorne Clemens (November 30, 1835 – April 21, 1910), best known by his pen name Mark Twain, was an American writer, humorist, entrepreneur, publisher, and lecturer. He was praised as the “greatest humorist the United States has produced”, and William Faulkner called him “the father of American literature”. His novels include The Adventures of Tom Sawyer (1876) and its sequel, Adventures of Huckleberry Finn (1884), the latter of which has often been called the “Great American Novel”. Twain also wrote A Connecticut Yankee in King Arthur’s Court (1889) and Pudd’nhead Wilson (1894), and co-wrote The Gilded Age: A Tale of Today (1873) with Charles Dudley Warner.- Apollo 15 Hammer-Feather Drop (youtube.com)
At the end of the last Apollo 15 moon walk, Commander David Scott (pictured above) performed a live demonstration for the television cameras. He held out a geologic hammer and a feather and dropped them at the same time. Because they were essentially in a vacuum, there was no air resistance and the feather fell at the same rate as the hammer, as Galileo had concluded hundreds of years before - all objects released together fall at the same rate regardless of mass.