I was watching a Vsauce video and learned that any two objects, like two baseballs, are attracted to each other because of their mass, and the bigger the mass, the more gravity an object has. What does mass have to do with gravity, and what causes gravity? Why does something just attract other things around it?
In: Physics
Your question made me research and learn about it. It’s funny because I didn’t do it at school… I guess I just needed the right incentive 🙂
I read this [answer](https://www.quora.com/How-is-gravity-generated-by-mass) and found it pretty interesting. Even due other people explained it great here so far
Since mass is an undefined, unexplained property, and always has been since it was introduced, physicists cannot answer: How is gravity generated by mass? However, answers abound. The reason why this occurs is because mass was arbitrarily made an undefined property. When mass was made an undefined property, disunity was immediately introduced into physics equations. The continue existence of fundamental disunity makes it possible for successful but partial theories to coexist. This flexibility results because the unexplained property of mass can be molded to fit into someone’s theory.
Mass could have been and should have been made a defined property along with force. Empirical evidence gives us guidance on how this can be done. The equation f/m=a shows the way by which mass can be made a defined property. The equation m=f/a doesn’t accomplish this because f=ma defined force. Solving the equation for mass cannot define mass because it would be a circular definition. However, f/m=a does contain guidance on how both force and mass can be individually defined. One must go directly to empirical evidence for definitions of both force and mass. Empirical evidence is represented by the letter ‘a’.
With regard to this question, there is no answer and will be no answer until mass is defined. I defined mass and have put it to work reproducing the equations of physics; but, all current highly favored theories are built with the undefined status of mass in their foundation. So, there seems to be little official incentive to define mass. However, there is no way to re-introduce fundamental unity into physics equations other than to go back and define mass. That will immediately regain fundamental unity for mechanics. For Thermodynamics defining mass will not be enough. Temperature must also become a defined property.
I watch a lot of science programs, so I’m an expert. My most basic understanding is that space is like a stretchy, invisible fabric with time woven within it. Material objects have mass and sit on the fabric. Depending how heavy or light the object is, affects how much it stretches the fabric, and how other objects fall in towards it.
On Earth, you only feel this falling in one direction: down. In space, far away from Earth, the falling effect is felt in all directions. You can fall towards heavy things like stars and planets every which way.
The concept gets harder, I think, when you start to realize time is also part of the fabric and is likewise getting stretched. But we are only talking about gravity.
Serious answer: Because.
Science ulitimately describes and models. It’s a mistake to assume that the descriptions and models, however good, are what’s actually happening, or “explain” it – even though that’s the language we tend to use.
Newton said roughly what you did – that bodies attract each other according to how massive they are (and also how far apart they are). That was a good fit to reality, but not a perfect one (notably, using Newton’s rules alone didn’t quite work to explain Mercury’s orbit).
Einstein described things in terms of curved space and time. That gave a better fit, and if you want to explain things in those terms, that’s fine (other people in this thread will and have described things in those terms). But just because the description is better, that doesn’t mean it’s necessarily what’s actually happening – it’s just a good match. It’s also incompatible with another excellent description of the way things “are”, namely quantum theory. One or both will have to give at some point.
It’s perfectly possible that, tomorrow, someone will make an observation that indisputably flies in the face of Einstein’s explanation – or maybe find a different way of describing things that works even better, and isn’t at odds with quantum theory. And then, quite possibly, we’ll be describing and “explaining” it in some other way completely. Either way it will still ultimately be a shorthand for “The universe behaves, roughly, as if this were the case” rather than “This is what is actually happening”.
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