Bruce Kabernagel, age 12, of Somerset, New Jersey, for his question:
Who really discovered gravity?
We tend to think that all the great brains of history were born in the 20th century. The truth is that every past generation had about the same quota of geniuses. Many of these old timers pondered profound problems, such as why objects fall down, adding their observations to the storehouse of human knowledge. Our modern scientists are able to make such astonishing advances because they inherited so much knowledge accumulated through past generations.
A caveman genius had to do all his thinking for himself, with no help from knowledge gained in the past. No doubt he wondered about running water, landslides and falling stones. But if he concluded that these events were caused by the force of gravity, he left no record of his theory. Through the ages, numerous other thinkers must have pondered the same problems.
The earliest gravitational experiment on record dates back to the 1600s. Galileo dropped a one pound weight and a ten pound weight at the same moment from the top of the Leaning Tower of Pisa. He wanted to find out which would hit the ground first. The race was a tie. Obviously Galileo was interested in falling bodies their rates and no doubt the reasons why they fall. In his lifetime, this genius also gave the world a new picture of the Solar System and challenged the popular notion that the earth is the center of the universe. His orbiting planets were, of course, governed by the still mysterious forces of gravitation.
The great Galileo died in Italy, in 1642. In the same year, Isaac Newton was born in the English village of Woosthorpe. Between, them, these two great men probed and formulated the laws of gravity. Galileo demonstrated the orbiting planets. Newton figured the precise ratios of gravity that keep them in their places.
Newton's family were farm folk and his father died before his son's birth. The boy used his clever hands to make clocks and sundials, toys and models. He also invented and modeled a self propelled carriage.. He was by nature a dreamer and later in life . his stepfather sent him to study at Cambridge University.
In 1667, England was struck by the Great Plague and the students were evacuated. Young Newton, aged 25, continued his thinking at home. In 18 months, he solved, among other problems, the laws of gravity for all posterity. Later, he became a math professor at his university. Maybe he forgot to publish his laws of gravity, maybe he spent the next 20 years writing them down in simple words, so that every school student can understand. A few interested parties heard about those precious notes, but they reposed, half forgotten in a drawer. Or so the story goes.
In 1687, the famous astronomer William Halley was tracking the orbits of comets. He heard about Newton's notes and arrived from London. Halley saw at once how Newton's laws of gravity were related to his orbiting comets. He coaxed Newton to publish his amazing work and helped to pay the cost of the printing.