Parachutes work by increasing air resistance, which slows down the effects of gravity. Air is a gas, and though it is invisible, the molecules in the gas can still be used to help slow down a skydiver, much like water slows down a person who does a belly flop in water. Therefore, the air expands the parachute, providing resistance as the person falls.
Manufacturers prefer nylon as it has proven to be a strong, springy material that makes parachutes that are lightweight, easy to pack, resistant to mildew and less expensive. Although many different materials have been used to manufacture parachutes, ripstop nylon is the most popular parachute fabric.
There are several theories about why fire engines are red. One theory suggests that fire trucks were first painted red back in the 1800s when fire brigades took so much pride in their trucks that they wanted them to stand out and feature the most regal and expensive color, which at the time was red.