We essentially have 4 fundamental forces: electromagnetism, weak nuclear, strong nuclear and gravity. Electromagnetism and weak, despite being different now, were the same force at some point earlier in the Universe.
Going further back in time, the strong nuclear force merges with electro-weak.
Gravity is different. We have no quantum theory and despite it being an old friend, it is the most mysterious.
Yes, very good question, and well answered by Eoin.
To add to that, gravity arises form mass or energy. The Earths gravity is 9.81 (in units of acceleration). Since Jupiter has much more mass than the Earth it has much more gravity. So you can think of gravity being formed anytime a collection of mass comes together as a planet or a star, or galaxy.
Gravity is a result of mass. More mass (or stuff) then more gravity. So as the Sun is bigger than the Earth, the Sun has a stronger gravity. There are experiments that are trying to detect gravitational waves. So far no luck, but more sensitive experiments are currently being designed. Hopefully we will detect them soon.
Comments
rb22 commented on :
Thanks for all the answers 🙂 🙂
Joseph commented on :
Our pleasure 🙂