Imagine a scenario where all of us on this planet were only volume and no weight. The mass that a volume carried had no meaning. What would have been the behavior of the apple then that Newton noticed falling from the tree? Would rain have happened as it happens now? Or, would rivers have existed as they exist today? What about oceans? Even what about our way of living?
All this would have been possible only if there was no gravitational force as we understand it today. An apple falls from the tree just because there exists the gravitational force of earth that acts upon the apple when it separates from the tree and is pulled towards the centre of the earth. There is an omnipresent invisible force that converts every mass into a weight according to the extent of mass it contained. This is the reason that every article acquires weight. More the mass it carries more is the weight acquired. It is so naturally acting on the matter that even if you think in your fig of imagination to lower the weight of an object by removing some amount of this gravitational pull, it has been just unimaginable so far.
Even then, if you are to imagine of the situation without gravitational pull of the earth, one may not be fully able to conceive the situation. The apple would never come down on the earth. We would not have felt weight of our body. Indeed, parents would then never have grumbled of the weight the tiny tots have to carry to their school. The rivers would never have had flown down and oceans would have been existed even without a bottom surface bearing them. If our bodies did not carry any weight, climbing Everest would never have raked in such awe and astonishment as it draws today. What more, there would not have been any need for waiting for so long to launch of a four ton plus satellite as we (India) have been striving today. It would have been like you just push a jump and would have been a floating experience till eternity or till someone stops you in between by halting your motion. Today, you may have known of such experiences by the astronauts in the space, where they drift inside the living space of their spaceships.
Oh! It was very random up there in the spaceship when we watched astronauts in some television programmes. Indeed; and would have been the same on earth if there was no presence of gravitation. Imagine chaos everywhere. Gravitation in fact is the reason behind all the orderliness on this planet. In fact the entire universe follows an order for this very cause. It lies in the planets going around the Sun, satellites encircling planets, solar systems ordering the centre of galaxies and so on. Even the man made satellites cannot, but follow this gravitation defined orderliness when a satellite is launched through powerful rockets to encircle the Earth. It revolves around in an orbit decided by the direction bearing speed it has attained at the time of ejection in to the orbit. The orbit is the path a heavenly body follows during its encircling its prima donna.
Each planet in the universe has its own gravitation decided by its own mass or size and its distance from the Sun. Also, each planet is acted upon by the field of the gravity of Sun. Sun’s size is almost 1000 times more than the size of planet Jupiter which is about 300 times massive than the Earth. So in our solar system, Sun is the most massive and hence having strongest gravity. This gravity also makes the planets move around the Sun. The entire universe is considered to have many galaxies each having many such solar systems.
Why the movement of planets or even satellites happens around the Sun in case of planets and around planets in case of their satellites? To understand this please recalls your hitting a target by throw of a cricket ball. The stronger is the throw, flatter is the trajectory. Slower the throw, the ball tends to turn towards the surface much earlier. In the absence of gravitational force, the ball would have travelled flat and parallel to the ground. This gravitational pull of the Sun makes planets drifting in the universe to take curved path around the Sun. This analogy is repeated in the case of a satellite orbiting the planet.
Now suppose we do something unique on this planet that the mass of Earth get doubled. This should change the amount of gravitational force and would ask for correction in the orbit of the Earth. This in all probability would be resulting in a shorter orbit around the Sun and hence shorter time for making one complete rotation.
So gravity has offered not only orderliness to this world of ours but also added the dimensions of achievements and excitement in our lives. But if again you are not content with your achievements against the influence of gravity, you may aspire to go to Moon to achieve higher feats. Because at Moon you would be able to jump six times your jump on the Earth. Any more guesses?