How gravity is responsible for everything from ocean tides to the stars

Did you know that gravity is actually considered the weakest force we know? It’s even weaker than the simple pull of a fridge magnet. That's why fridge magnets do not fall.

So how is it responsible for everything from ocean tides to the formation of stars to the weight of every physical object? To understand its power we must first consider Sir Issac Newton’s early theory.

The scientist proclaimed that anything with mass will attract anything else with mass. The heavier the object, the stronger the attraction. The farther apart the objects, the weaker the attraction. His theory dominated until Albert Einstein came along with the theory of general relativity. 

Einstein proposed that gravity was not a force but a distortion or warping in the shape of space-time caused by massive objects, such as the planets and stars. This assumption remains to this day one of the best explanations of gravity. 

But what does this theory really entail? How does it explain the fact that gravity is not the same everywhere on Earth? Why does it also vary from planet to planet and why do we need it to survive here on Earth? This video answers all these crucial questions and more.