Leonardo da Vinci once said, "Art is never finished. So it may not be surprising that he only completed about 12 paintings. These, s Mona Lisa and The Last Supper, two of the world's most famous paintings. Today, But he was more everyone knows about Leonardo the artist. than that. He was also a scientist. Leonardo da Vinci is often called one of history's greatest thinkers. Imagine the world of 500 years ago. At that time, few people were inventing new things. Bulent Atalay, who wrote a book about Leonardo, says, "He invented the future. Leonardo studied engineering and physics. He was also interested in the science of flight. With all of that knowledge, 15 he imagined flying machines-400 years before the first airplane! Leonardo drew many ofhis ideas. They had incredible detail other people have used his designs to make parachutes, and inventions similar to today's submarine and telescope Leonardo's drawings showed all these things hundreds of years before anyone else! His drawings also showed how the machines of his day worked. In fact, today we can still use them to make models that work!