Is there something wrong with the theory of gravity?
It seems greater mass simply creates more mass. Gravity is much more powerful on earth compared to the moon. So, mass creates gravity?

answers:
Carson say: Based on your question, I'm not sure that you understand what the theory of gravity actually is and that's okay, it's a complex topic (especially the deeper you dive into it) and I'll happily explain how it works. For clarification, I am explaining Newton's Gravitational Theory first in respect to your question and then I will be relating it back to the theory of gravitational relativity, which answers your question in a slightly different way.
So first of all, let's understand the actual equation for gravity itself. Gravity is calculated using F = Gm1m2/r2. This equation basically states that gravitational force between two bodies is proportional to the product of their masses, and inversely proportional to the square of the distance between them.
What I think you meant by "greater mass simply creates more mass" is that the weight of an object increases when acted upon by a body of greater mass, which is true, but mass and weight are very different things. Mass, is a measure of how much matter is in an object, and this will never change. Weight, is a measure of downwards gravitational force, which can change. If I am standing on the moon, I will have the same physical composition as when I'm standing on Earth, but I will weigh less because the moon has less mass than the earth so it is exerting a weaker gravitational force on me.
But to answer the question "Is there a problem with the theory of gravity?" by itself, yes there are a couple problems with Newton's Gravitational Theory, which is why it was replaced by Einstein's theory of gravitational relativity. The problem is not so much the “gravity” part— newtonian gravity is extremely accurate, the problem mostly lies with the idea that gravity is an instantaneous "action at a distance" because this assumes gravity can react at an infinite speed, when in reality it is limited to the speed of light. For this reason, as well as a few others which I have not delved into, Gravity given our current understanding is best described using the equation E=MC^2.

roberto say: mass does not reproduce

JosephV say: No. Nothing is wrong. Forces may have a concave front to you (you are a proton at this level) or forces may have a convex front to you. One expands, repels, and collides creating volume. The other contracts, attracts and absorbs, reducing volume.
Build up on this keeping your baryon number intact, and gravity with graviton is very much a part of our universe with magnetron, neutron, electron, and photon.

Clive say: Greater mass does not create more mass. But yes, mass creates gravity, and the amount of gravity is directly proportional to mass. The Moon has less mass than the Earth, therefore you have less weight there.

Tom S say: You could say that matter propagates a gravitational field, or gravity is a property of mass/matter. Also, yes there are problems with the theories we have for it, like not being compatible with quantum mechanics.
https://www.aei.mpg.de/18228/03_Quantum_...

Ronald 7 say: Gravity is in proportion to Mass

gregory_dittman say: On a simple answer mass creates gravity. On a more complex answer, it's a particular atomic particle that creates gravity that is right now called a graviton. We know no nothing about this particle including if it has mass.

hoarseman say: I think every scientific theory has been superseded over time,so I suspect it's virtually certain that there is something wrong with our current theory of gravity  not withstanding the fact that we observe that "energy" gravitates.

poldi2 say: Yes, mass creates gravity.
Greater mass creates more gravity (not more mass).

BillM say: Gravity is not a Theory. It exists. Yes  Mass creates gravity. All mass has gravity, even you.

Argent say: Yes, mass creates (or causes) gravity. Mass does not create mass, however  it creates gravitational force.

Carson say: Based on your question, I'm not sure that you understand what the theory of gravity actually is and that's okay, it's a complex topic (especially the deeper you dive into it) and I'll happily explain how it works. For clarification, I am explaining Newton's Gravitational Theory first in respect to your question and then I will be relating it back to the theory of gravitational relativity, which answers your question in a slightly different way.
So first of all, let's understand the actual equation for gravity itself. Gravity is calculated using F = Gm1m2/r2. This equation basically states that gravitational force between two bodies is proportional to the product of their masses, and inversely proportional to the square of the distance between them.
What I think you meant by "greater mass simply creates more mass" is that the weight of an object increases when acted upon by a body of greater mass, which is true, but mass and weight are very different things. Mass, is a measure of how much matter is in an object, and this will never change. Weight, is a measure of downwards gravitational force, which can change. If I am standing on the moon, I will have the same physical composition as when I'm standing on Earth, but I will weigh less because the moon has less mass than the earth so it is exerting a weaker gravitational force on me.
But to answer the question "Is there a problem with the theory of gravity?" by itself, yes there are a couple problems with Newton's Gravitational Theory, which is why it was replaced by Einstein's theory of gravitational relativity. The problem is not so much the “gravity” part— newtonian gravity is extremely accurate, the problem mostly lies with the idea that gravity is an instantaneous "action at a distance" because this assumes gravity can react at an infinite speed, when in reality it is limited to the speed of light. For this reason, as well as a few others which I have not delved into, Gravity given our current understanding is best described using the equation E=MC^2.

Who say: according to einstein mass does not actually create gravity itself 
mass distorts space/time
its this distortion that creates the effect of gravity, not the mass itself
yes a bigger mass results in stronger gravity
but the bigger mass only creates a bigger distortion
if you could remove the mass but leave the distortion it created then gravity would still exist
so gravity aint the result of the mass"pulling" stuff towards it, its the distortion pushing the stuff towards the center of the distortion (where the distortion is at its maximum and therefore the effect of gravity is also a maximum)

CarolOklaNola say: Yes, mass creates creates gravity.
The theory of gravity is incomplete. Watch the latest episode of How the Universe Works.
