Gravity is the force that keeps you glued to Earth. Except it is not a force as it is a space-time distortion generated by the presence of mass. But we will still be able to use formulas for it and still call it a force.
There are three formulas for force:
– F = m * g – the simplest formula that lets you calculate gravity when you are on Earth
– F = G m1 * m2 / r^2 – this formula lets you calculate the gravity force between different object and even what the gravity on another objects is. Also, solving the differential equations that derive from the fact that all bodies attract to each other lets you calculate the orbits of cosmic objects
– this is the field equation for gravity created by Einstein and which are at the core of General Relativity.
The last one was created by Einstein because the second one could not explain all the things related to gravity that we could see. Solutions to this last formula give us data about black holes, gravitational lensing or about the accelerated expansion of the Universe (the Lambda term > 0).
Are you a math or physics genius? Solve the lat equation.