What does gravity do

The answer is gravity: an invisible force that pulls objects toward each other. Earth's gravity is what keeps you on the ground and what makes things fall. An animation of gravity at work. Albert Einstein described gravity as a curve in space that wraps around an object—such as a star or a planet. If another object is nearby, it is pulled into the curve.

Image credit: NASA. Anything that has mass also has gravity. Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body. That's what gives you weight. And if you were on a planet with less mass than Earth, you would weigh less than you do here.

You exert the same gravitational force on Earth that it does on you. Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth. Surely, gravity must be a force in order to pull things, right? Share This Article. More on Hard Science. New Moon Just Dro Mystery Meat. Keep up. Subscribe to our daily newsletter to keep in touch with the subjects shaping our future. Topics About Us Contact Us. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Futurism.

Fonts by Typekit and Monotype. In this article, we'll look at Newton's theory of gravity, Einstein's theory of gravity and we'll touch on a more recent view of the phenomenon as well. Although many people had already noted that gravity exists, Newton was the first to develop a cohesive explanation for gravity, so we'll start there. In the s, an English physicist and mathematician named Isaac Newton was sitting under an apple tree -- or so the legend tells us. Apparently, an apple fell on his head, and he started wondering why the apple was attracted to the ground in the first place.

Newton publicized his Theory of Universal Gravitation in the s. It basically set forth the idea that gravity was a predictable force that acts on all matter in the universe, and is a function of both mass and distance. The theory states that each particle of matter attracts every other particle for instance, the particles of " Earth " and the particles of "you" with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

The standard formula for the law of gravitation goes [source: UT ]:. G has the value of 6. So if you put two 1-gram objects 1 centimeter apart from one another, they will attract each other with the force of 6.

A dyne is equal to about 0. That's why you're not floating around in space right now. The force of gravity acting on an object is also that object's weight. When you step on a scale, the scale reads how much gravity is acting on your body. The formula to determine weight is [source: Kurtus]:.

Acceleration due to gravity on Earth, is 9. That's why if you were to drop a pebble, a book and a couch off a roof, they'd hit the ground at the same time. For hundreds of years, Newton's theory of gravity pretty much stood alone in the scientific community. That changed in the early s. Albert Einstein , who won the Nobel Prize in Physics in , contributed an alternate theory of gravity in the early s. It was part of his famous General Theory of Relativity, and it offered a very different explanation from Newton's Law of Universal Gravitation.

Einstein didn't believe gravity was a force at all; he said it was a distortion in the shape of space-time, otherwise known as "the fourth dimension" see How Special Relativity Works to learn about space-time.

Basic physics states that if there are no external forces at work, an object will always travel in the straightest possible line. Accordingly, without an external force, two objects travelling along parallel paths will always remain parallel. They will never meet. But the fact is, they do meet.