In 1854, Ferdinand de Lesseps, the former French consul to Cairo, planned and constructed the Suez Canal of 100 miles across the Isthmus of Suez. In 1875 <span>it was finished. </span><span>When it opened, the Suez Canal was only 25 feet deep, 72 feet wide at the bottom, and 200 to 300 feet wide at the surface.</span>
The understanding of gravity was essential in the developmentof Albert Einstein theory of relativity. Which describe relationships between matter and motion.