Gravity is a natural force that acts upon all objects. It causes smaller objects to pull towards larger objects.
Gravity is a natural force which affects us every day, and is a regular part of our life, which is why we don’t pay much attention to it. According to the theory of gravity, it is a force due to which all objects with mass gravitate or pull towards each other. This includes small everyday items such as a glass or bottle, us, humans and animals, to large solar objects such as Earth, Moon, Sun, Stars, etc.
Any object that has mass has a gravitational pull. This means that anything that can be touched is affected by gravity. The more mass an item has the more gravity pull it has, which is why when we walk on Earth, it pulls us down to its surface. This is the main reason that we are stuck to the surface of the Earth, and not floating off into space. Yet, while the Earth’s gravity pulls us down, we also have a gravitational pull that pulls at the Earth. However, our size is so small as compared to the Earth’s, that our gravitational pull is negated by the one of the Earth.
In addition to mass, gravity is also affected by distance, which is why even though the Sun is much larger than the Earth, its gravity does not pull us away from the Earth. It is because it also much farther away from us. However, its gravity is strong enough to have an impact on the Earth as a whole, which is why the Earth is in orbit around the Sun, similar to how the Moon is in orbit around the Earth.
The Sun’s gravity pulls the Earth toward it. The reason the Earth has not plummeted into the Sun is because the Earth’s gravitational pull resists the Sun’s. So, the Sun’s gravity and the Earth’s gravity exist in tandem, both pulling at each other, similar to a tug of war. Eventually, they have come to a stalemate with the Earth revolving around the Sun. The same phenomenon is also causes the Moon to revolve round the Earth.
The reason behind gravity’s existence is a bit more complicated. The simplest way to define is that an object causes the space round it to bend, which causes it the surrounding space to dip. Think of a ball on a sheet or a trampoline. The ball causes a depression, which causes other smaller objects to roll toward the bigger object and into the dip. This is exactly what happens in space, but on a much larger scale and with many different objects in play at the same time.
Image Courtesy: eschooltoday.com, spaceplace.nasa.gov