We experience gravity constantly and it affects every move we make. From the moment we are born we experience gravity and we start learning it rules. Everything on Earth’s atmosphere is attracted to Earth constantly. But why is there gravity? From Isaac Newton’s law of gravitation we know that we exert a force of attraction to each other.The relationship is based upon the mass of the objects and the distance between them. The greater the mass , smaller the radius and shorter the distance, the stronger the gravitational pull is. Every object with mass attracts any other object in its range, but because of the small gravitational pull of objects in Earth, many variables like air resistance doesn’t let the objects move in such a small scale.
To calculate the force of gravity between two objects we can use this formula:F = gravitational field strength (N/kg)G= gravitational constant (6.67408 × 10-11)m1 = mass of the first object (kg)m2 = mass of the second object(kg)r = distance between the center of massesBut with his theory of relativity, Albert Einstein explained how gravity is more than just a force. It is a curvature in the space-time continuum. The mass of an object causes the space around it to bend and curve. We can’t see the curvature of space directly, but we can detect it in the motions of objects. Any object caught in another celestial body’s gravity is affected because the space it is moving through is curved toward that object. Gravity is also what holds the planets in our solar system into orbit around the sun and what keeps the moon in orbit around Earth. The gravitational pull of the moon pulls the seas towards it, causing the ocean tides.
Gravity creates planets by pulling together the materials from which they are made.Black holes have so much mass in such a high density that their gravity is strong enough to keep anything, even light, from escaping.Gravity does not only pull mass but also light, which is supposedly weightless. Albert Einstein discovered this principle. If you shine a flashlight upwards, the light will grow imperceptibly redder as gravity pulls it. You can’t see the change with your eyes, it can be measured with machinery.Another experiment that also further proved his theory of relativity is that at the right time, at the right place using a telescope during an eclipse, you can notice light from other stars being slightly being distorted than usual. But the difference is tiny, only a couple mm using a telescope.