Where does gravity come from?

Question

In class today, my professor mentioned that people still don't know why gravity exists. It seems to me that gravity is just the result of large scale electromagnetic forces. It can't just be a coincidence that the equation for the force gravity and for the force of electric charges are the same, can it? what do you guys think?

Answer 1

That's what i think too. When you have something as big as the Earth, the charge from all the protons in Earth's atoms probably cant attract electrons from far far away in other atoms. I guess the problem is that no one has been able to prove it.

Answer 2

Gravity is one of the four unique types of force found in the universe: (1) Gravitational, (2) Electrostatic, (3) Strong nuclear (binding), and (4) Weak nuclear force. Magnetic forces are the result of electrostatic forces.

As to where it comes from, anyone's guess is as just about as good as another's. Gravity is a intrinsic part of the universe, like mass. As such, you might as well ask "Where did mass come from?" or "Where did the universe come from?"

Aristotle's views of the natural world were not scientific - he was an ancient philosopher. Newton believed (it is thought) that space and time were independent, but then he did say that force = dp/dt, where p = mv, and not strictly f = ma, thus possibly leaving the door open for the idea of space and time being intertwined. But Newton believed that space was Euclidean. Later, it was conjectured that space was more Riemannian, that through a point not on a line there are no lines through that point that is parallel to the given line - they all eventually intersect (elliptic geometry). This supported Einstein's view in which mass bends space. That is, straight lines, as in the matter of motion of bodies, are affected by mass. So, this is a different take on gravity.

None of this says, however, where gravity comes from.

Answer 3

There have been 3 main types of scientific gravity explanation.

1. William Gilbert type, bodies emit some signals that other bodies respond to like simple robots.
2. Rene Descartes type, some material ether between bodies pushes them.
3. Albert Einstein type, some forcefield between bodies energises them.

Isaac Newton concluded that gravity involves an unobservable requiring hypotheses which are not a valid part of experimental science. Newton was suspected of privately favouring Gilbert signal attraction, but was a declared blackbox-science neutral on what causes gravity.

Answer 4

It is true that we don't know why gravity exists. All we can say is that God chose it as a property of the physical universe He created.

For the rest, you need to learn some physics. As far as we can tell, gravity has no relationship to electromagnetism. The equations are not at all the same. Perhaps it it coincidence that both gravitation and electrostatic attraction are inverse square with distance.

Answer 5

Excellent observation.

Answer 6

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html