Faye Panders, age 13, of Vancouver, Wash., for her question:
WHAT DID SIR ISAAC NEWTON DO?
Sir Isaac Newton was one of the world's great physical scientists. An Englishman who lived more than 300 years ago, he is the man who discovered the law of gravitation.
Newton made many contributions to science and mathematics that continue to be important today. He was able to combine a skill in experimentation with an unusual ability in mathematics. His greatest book, called "Mathematical Principles of Natural Philosophy," or "Principia," has influenced civilization ever since it was published.
Man's current interest in outer space owes much to Newton's discoveries in light, motion, gravitation and mathematics.
Newton received a bachelor's degree from Cambridge University in 1665 when he was 23 years old. Just then the bubonic plague called the Black Death hit, closing the university for more than two years. It was during this period that Newton made many of his greatest discoveries, although it wasn't until much later that they were published.
When he was 26 years old, he became a professor of mathematics at Cambridge. In 1699 when he was 57 years old, he was named master of England's mint. He held the job until his death at the age of 85 in 1727.
Also, for the last 24 years of his life he was president of a most distinguished body of scientists and philosophers called the Royal Society.
Before he was 25 years old, Newton had discovered the binomial theorem, one of the first and most useful of theorems infinite series. To prove that a spherical body like the earth would attract as if all its mass were situated at its center, Newton invented "fluxions" which we now know as differential and integral calculus.
When Newton had a problem to solve, he simply invented the mathematics he needed to do the job.
Newton is buried in London's Westminster Abbey.
Newton's interests were so wide and his combination of experimental and mathematical skills so great that he was able to use one of the first thermometers for measurements of heat.
The scientist was also one of the first to measure the velocity of sound. His ideas on motion are the basis of "Newtonian mechanism."
Before Newton's time, men had studied refraction, or the bending of light as it enters water or glass, and they knew why rainbows form in sunlight as water droplets pass through. But no one could explain why the rainbow was colored. Newton came up with the answer.
Newton explained that red light is refracted slightly less than blue and that other colors lie between.
His observations on the nature of white light later led to the important field of spectroscopy.