Gravity is the mystical, invisible force which keeps our feet on the ground. It’s everywhere around us in the universe. Isaac Newton discovered this the hard way when an apple fell from a tree and onto his head. Luckily it didn’t ruin his day, instead he started questioning why the apple had been so mean to him. Why did it knock him in the head? Then it occurred to him the apple had no problem with him as a human being, the apple wasn’t jealous at all, there was instead a mystical force making the apple fall to the ground.
Let’s put all our cards on the table; we don’t really know what gravity is. If you were to ask a scientist what gravity is he would scratch his head, hoping you haven’t asked him that question. Because he couldn’t have given you a solid answer to what gravity is on a fundamental level, he could only have told you how it behaves.
So how does it behave?
We know gravity is the attraction between two objects. Every object is attracted to one another, similar to a magnet. Like you and the Earth, or the Earth and the Sun and so on.
The size of the gravitational pull depends on the mass of the object. That is why our planet orbits the Sun and not the other way around, because the Sun has got more mass.
A common misconception when talking about mass is people tend to believe bigger planets contains more mass. That is NOT the case. A small planet can contain more mass than a bigger planet, because the mass can be more dense. The planet is more compressed together (like a hard snowball); we say its got a higher density. This applies not only to planets, but to everything.
This attraction of gravity exists in every corner of our universe. It’s what makes stars form, it’s the building blocks of black holes, it’s the reason why planets are circular, it’s basically what keeps the universe in order. Without gravity we would all be floating out in space, there would be no planets to live on and the universe might not even existed. Life would suck, to be honest. So lets all be happy gravity exists because we would not be alive without it.
This article is a respone to Gael Blanchemain who used our Question Form (found on the frontpage in the sidebar) to ask us a question. If you’ve got a question you are welcome to send it in, and your question might also be answered in an article.