Why do we have gravity? what creates gravity???

Answer 1

There are two forces in nature that we experience every day: gravity and magnetism. You may have magnets on your refrigerator, and you know that a magnet will attract a refrigerator with a certain amount of force. The force depends on the strength of the magnet and the distance between the magnet and the metal. You also know that magnets have two poles -- north and south. Either pole will attract iron or steel equally well, north will attract south, and like poles will repel one another.

Gravity is the other common force. Newton was the first person to study it seriously, and he came up with the law of universal gravitation:

Each particle of matter attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Answer 2

The why questions ask for a reason.
I guess we may be grateful we do not float anywhere.

What creates gravity is another question.
Only Einstein gave an 'understandable' answer.
Space time has been curved near places where a mass is.

Aether theory without calculations is very interesting. However it never brings you to Gravity = GMm/d2.

Answer 3

Actually, according to Einstein...Gravity is an illusion caused by a the curvature of space-time...think of space time like a trampoline...now imagine that we have a grid covering the surface of the trampoline...if you were to place a bowling ball on that trampoline...you would notice the squares around it strain and stratch toward point where the bowling ball touches the trampoline. Basically Einstein said that what we perceive as gravity is that strain in the actual fabric of space.

Answer 4

Hey!! Gravity is just a *THEORY*!!

Evangelical Scientists Refute Gravity With New 'Intelligent Falling' Theory:

http://www.theonion.com/content/node/39512

Well. Now we know.

Answer 5

Centripetal force.
Imagine you tie a string to a stone and spin the string. The force you experience in your hand is directly proportional to the velocity of the spin. There is a force exerted on the string to keep it straight.

Now, Earth rotates very fast. You are in there (as a stone in this example). The gravity is the string.

Understand this concept now?

Answer 6

Gravitation or Gravity is the tendency of objects with mass to accelerate toward each other. Gravitation is one of the four fundamental interactions in nature, the other three being the electromagnetic force, the weak nuclear force, and the strong nuclear force. Gravitation is the weakest of these interactions, but acts over great distances and is always attractive. In classical mechanics, gravitation arises out of the force of gravity (which is often used as a synonym for gravitation). In general relativity, gravitation arises out of spacetime being curved by the presence of mass, and is not a force. In quantum gravity theories, either the graviton is the postulated carrier of the gravitational force, or time-space itself is envisioned as discrete in nature, or both.

The gravitational attraction of the Earth endows objects with weight and causes them to fall to the ground when dropped (the earth also moves toward the object, but this is so small the effects are negligible at best ). Moreover, gravitation is the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and life as we know it would not exist. Gravitation is also responsible for keeping the earth and the other planets in their orbits around the sun, the moon in its orbit around the earth, for the formation of tides, and for various other natural phenomena that we observe.

In 1687 Newton published his work on the universal law of gravity in his Mathematical Principles of Natural Philosophy. Newton’s law of gravitation states that: every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. If the particles have masses m1 and m2 and are separated by a distance r.the magnitude of this gravitational force is:

F = G (m1) (m2) / r^2

where:
F is the magnitude of the (repulsive) gravitational force between the two point masses
G is the gravitational constant
m1 is the mass of the first point mass
m2 is the mass of the second point mass
r is the distance between the two point masses

Every planetary body, including the Earth, is surrounded by its own gravitational field, which exerts an attractive force on any object that comes under its influence. This field is proportional to the body's mass and varies inversely with the square of distance from the body. The gravitational field is numerically equal to the acceleration of objects under its influence, and its value at the Earth's surface, denoted g, is approximately 9.81 m/s² or 32.2 ft/s². This means that, ignoring air resistance, an object falling freely near the earth's surface increases in speed by 9.81 m/s (around 22 mph) for each second of its descent. Thus, an object starting from rest will attain a speed of 9.81 m/s after one second, 19.62 m/s after two seconds, and so on. According to Newton's 3rd Law, the earth itself experiences an equal and opposite force to that acting on the falling object, meaning that the earth also accelerates towards the object. However, because of the low mass of the falling object, its gravitation is vanishingly small, and the resulting acceleration of the earth is negligible.

Hope you understood the concept.

Answer 7

Everything is attracted to each other based on mass. You exert a pull on a table you are standing next to, and it exerts one on you, but the relative difference in mass is so small, you do not experience a noticeable pull. The mass of the earth however is so much larger than you, that you can feel it's pull- at 9.8 m/s2, just as the sun's mass is so much larger than the earth, that the earth orbits the sun, caught in it's gravitational pull.

Answer 8

We have gravity simply because the earth rotates. I know it seems topsy-turvy, but according to the experts, if the earth were to stop spinning, only then would we be flung out to space. Seems like it would be the reverse, doesn't it?

Answer 9

Ditto with KAIN. Electromagnetism. Electrons hold everything together, hold us down, and push against us.

Gravity is electromagnetism.

Answer 10

haaa good question...Listen up if u have mass u will have the gravitational pull acting on you.Suppose the mass of earth is M and your mass is m then the gravitational force existing between you and the earth is (GmM)/(r ^ 2) where G is the gravitational constant and r the radius of earth(assuming your position to be at sea level).Now this force is equal to your weight: mg....Thus comparing the two quantities we have g=(GM)/(r ^ 2) which is the acceleration due to gravity.
.....................................BYE.........................................................