The Airplane

Just as the locomotive made the world a smaller place in the nineteenth century, the airplane did the same for us in the twentieth century, shrinking our planet to the point that a person could fly anywhere in the world in a matter of hours. Not only have they made travel quick and safe, but aircraft provide many other services as well: from crop dusting and fighting forest fires to overnight delivery of packages and chasing hurricanes. They have also revolutionized warfare, turning battle into a long-range affair fought at arm’s length by machines of such sophistication that the way wars are fought has completely changed. Of course, they’ve also been responsible for leveling whole cities and bringing war to the civilian population—who had rarely been directly affected by war until the twentieth century—but then no invention is perfect.

Source:

http://www.toptenz.net/top-10-inventions-of-the-20th-century.php