Speaking of physical discovery, the idea of ‘’gravity’’ will definitely show up in many people’s mind. It is said that hundreds of years ago, when a scientific and mathematical genius- Issac Newton was in Cambridge University, something happened that spurs him to discover the important theory. When Newton was eating an apple, studying under an lush apple tree; suddenly, a stream of breeze blew by, an apple fell down and hit right on his head. ‘’Ouch!’’ said Newton. Holding an apple in his hand, Newton started to be curious about why the apple drops instead of drifting in the air. After years of research, Newton suggested the theory of gravity, which is an essential discovery that affect a multitude of scientific researches afterwards.
Hundreds of years after Newton’s study, human got to have chances to go outer space. People then found out that astronauts in the space lives under the environment without gravity, which is very inconvenient. When they want to take a shower in such occasion. Water dews drift in the air, so the astronauts have to try their best to wet their hair as to finish the cleaning. Which is a subtle and very easy action to do under the land with gravity. Also, without gravity, those agents work outer space usually encounter some difficulties such as they have to attach themselves to the sleeping bag fixed on the spaceship for the sake of floating in the room and bumping around. It is after people’s myriad experiences without gravity that we understand the importance of ‘’gravity,’’ which is the most significant discovery in the seventeenth century.