Inventions That Changed the World

7. Railways

Railways can carry a large number of passengers with comfort while also being able to haul heavy loads to long distances. While tracks, or rails, had been in use for carrying wagons since the sixteenth century, the history of modern train travel is just over 200 years old.
The first full-scale working railway steam locomotive was built in the United Kingdom in 1804 by Richard Trevithick, a British engineer. It used high-pressure steam to drive the engine. On 21 February 1804, the world's first steam-powered railway journey took place when Trevithick's unnamed steam locomotive hauled a train along the tramway in Wales. 
However, Trevithick's locomotives were too heavy for the cast-iron plateway track then in use. The commercial appearance of train networks came in the 1820s. In 1821, George Stephenson was appointed as an engineer for the construction of the Stockton and Darlington Railway in the northeast of England, which was opened as the first public steam-powered railway in 1825. In 1829, he built his famous steam engine, Rocket, and the age of railways had begun. 

8. Airplane

Source: ingewallumrod/Pixabay
On December 17, 1903, Wilbur and Orville Wright achieved the first powered, sustained, and controlled flight.
While flying machines had been dreamt up since Leonardo da Vinci's time, and likely long before, and thanks to the work of countless inventors over several centuries, the Wright Brothers became the first people to achieve controlled, powered flight. Beginning with their work on gliders, the duo's success laid the foundation for modern aeronautical engineering by demonstrating what was possible.

9. Fire

Though fire is a natural phenomenon, its discovery as a useful tool marks a revolution in the pages of history. In fact, the controlled use of fire likely predates the emergence of Homo sapiens.
There is evidence of cooked food from around 1.9 million years ago — before the evolution of Homo sapiens. There is also evidence for the controlled use of fire by our ancestors, Homo erectus, beginning around 1,000,000 years ago. Flint blades that have been burned in fires have been dated to roughly 300,000 years ago. There is also evidence that fire was used systematically by early modern humans to heat treat stone, to increase its ability to flake, for use in toolmaking around 164,000 years ago.
According to a heavily debated hypothesis, it was the use of fire for cooking that allowed the larger brain of Homo sapiens to develop in the first place, by allowing hominids to eat a wider variety of foods.
From the past to the present, fire has been used in rituals, agriculture, cooking, generating heat and light, signaling, industrial processes, and as a means of destruction. It can easily be considered to be one of the leading inventions that changed the world.