Is Gravity Relative to Density Alone

[mAMBOkING]

I apologize if this comes off as a dumb question, but does anyone know if gravity is ABSOLUTELY simply dependent on density alone, regardless of the type of material itself, or does the type material also factor into it's gravity?

 

[Drakkith]

Density: The mass density or density of a material is defined as its mass per unit volume.

I would say yes. The materiel itself obviously can be different, which would have different densities, but its still mass per volume.

 

[D H]

I apologize if this comes off as a dumb question, but does anyone know if gravity is ABSOLUTELY simply dependent on density alone, regardless of the type of material itself, or does the type material also factor into it's gravity?

Mass, not density. That gravitation is independent of the type or composition of material is one of the principle assumptions of general relativity.

This assumption, if false, would completely dismantle general relativity. An untested core principle is a bad thing, so of course this assumption has become one of the most precisely tested and verified principles of all of physics.

 

[TurtleMeister]

Not a dumb question at all. It's a question I've thought about a lot. And even though the composition dependency of passive gravitational mass has been thoroughly tested, from Newtons pendulum experiments to STEP, the case for active gravitational mass has received very little attention. In fact, the one and only laboratory test to date is the Kreuzer experiment of 1968. It obtained a precision of 5x10^-5. Compare that to the better than 1x10^-11 precision for passive gravitational mass experiments. So this principle assumption of GR is not as well tested as most people think.

 

[pmacias]

I can assure you that this is not a dumb question at all. In fact, it is a very important and complex topic in the field of physics. The short answer is that gravity is not solely dependent on density alone, but rather it is influenced by several factors including mass, distance, and the type of material.

Firstly, it is important to understand that gravity is a fundamental force in the universe that attracts all objects with mass towards each other. The strength of this force is directly proportional to the mass of the objects and inversely proportional to the square of the distance between them. Therefore, the greater the mass of an object, the stronger its gravitational pull will be.

Now, when it comes to the relationship between density and gravity, it is true that objects with higher density tend to have a stronger gravitational pull. This is because density is a measure of how much mass is packed into a certain volume, and as we know, mass is a key factor in determining the strength of gravity.

However, the type of material also plays a significant role in the gravitational pull of an object. This is because different materials have different densities, but they also have different masses and compositions. For example, a planet made of iron will have a stronger gravitational pull than a planet made of ice, even if they have the same density.

In addition, the distribution of mass within an object also affects its gravitational pull. For instance, a hollow object with the same mass as a solid object will have a weaker gravitational pull because its mass is spread out over a larger distance.

In conclusion, while density is an important factor in determining the strength of gravity, it is not the only factor. The type of material, mass, and distribution of mass all play a role in the gravitational pull of an object. Therefore, gravity cannot be solely dependent on density alone.