what is it that gives a planet the property of gravity. Can it be created in the lab?

Question

i mean an elaberate answer. this is something i have never really figured out

Answer 1

"centrifugal" or more properly "centripetal" force has nothing to do with gravity. Nor is gravity electromagnetic as many thing.

Gravity is said to be an intrinsic property of mass. This is like saying the color gold is an intrinsic property of gold...in a sense it is part of the definition.

The nature of gravity is such that if you dropped a bowling ball and a feather from the same height on the moon, or in the presence of any gravitation field within a vacuum so there were no wind resistance, the bowling ball and feather would fall at the same rate. They would hit the ground at the same time.

Even though the bowling ball is heavier....the pull "adjusts" so that each object falls at the same rate.

As far as we know, the law of gravitation has the same form as the law of electromagnetism.

The electromagnetic field outside of a charged particle is expressed as: E = (KQ)/r^2 where E is the acceleration caused by the field at that point, K is a constant, and r is the distance from the particle.

For the force: F = (KQq)/r^2 where q is another charged particle

For the gravitation field outside of a particle of mass: g = (GM)/r^2
g is the acceleration, G is a constant, M is the mass, r is the distance.

For the force. f = (GMm)/r^2
where m is another particle of mass.

Scientists find ths quite curious as no mathematical relation seems to exist between gravity and electromagnetism other than this similarity.

Gravity is a weak force and electromagnetic force is a strong force. Gravity holds us to the ground yet it's weak enough that we can lift our foot off of it. It takes a tremendous amount of energy to rip an electron away from a proton, however (or two magnets away from eachother) compared to gravity.

It's speculated that gravity may have a wave/particle nature in the form of gravitational waves and gravitons

In short, we don't know exactly what causes mass to have gravity. Some speculate that gravity is actually very complex in that it acts in many dimentions. Some speculate it's a weak force because it leaks off into another dimention and that there may exist a place (that we can't get to) where it's just as strong as the electromagnetic force is here.

I hope that helps.

Centripetal force can simulate gravity in that it creates an acceleration which cannot be distinguished from that of a gravitational field. The principal behind this is the fact that in the abcense of any net external forces, an object in motion will go in a straight line.

Now imagine you are in a ring shaped spinning space station standing on the floor due to the artificial gravity.

If the floor suddenly dissapeared you would go flying out, but you wouldn'y fly out away from the center of spin. You'd actually fly off tangent to the point at which you were standing because at that very second you were going in a particular direction (the same direction as the point of floor you were standing on, and so with nothing to stop you, you keep going in that direction.

That being said, with the floor there, it keeps pushing you in towards the center of spin, keeping you from flying off on a tangent. The summed vector diagram for this looks exactly like the one for a gravitational force and so the universe is content and all is well:)

Answer 2

The thing which gives a planet, star or anything else the property of gravity is called mass.....the amount of matter that an object has. So, the more matter that an object contains, the greater the mass and therefore the higher the gravity. Density only has a little to do with it. Look at Jupiter and the Earth. Jupiter's density is around 1.4 gms/cm^3. Earth is 5.56gms/cm^3. But Jupiter's gravity is 2.64g as compared to Earth's 1g, because Jupiter is 318.8 times more massive than we are and 1308 times more voluminous.

No you're probably wondering what gives matter mass??. Well you may ask......there is a particle which has been mathematically shown to exist but hasn't been found in particle accelerators yet, called the Higgs Boson. It belongs to the same family of particles, the bosons, as electrons and protons do. However, the Higgs Boson is an extremely heavy particle......many times larger than a proton. Even much larger than the W and Z particles which act as agents for the weak and strong nuclear forces. This particle, whilst being as heavy as it is, only lasts for a trillion millionth of a second, before it decays into less massive particles. The Higgs Boson is the mediator in giving matter its mass, and probably upon decay gives off gravitons....hypothetical gravity paricles, as well as other particles and radiation.

Can they be created in a lab? No, not yet. We don't have particle accelerators with enough power to generate the energies needed to produce Higgs particles and gravitons. But we might have soon enough when new versions of particles accelerators come online in the near future.

Answer 3

What the hell?

It is amazing how many people in the Physics category can't remember the FIRST principle taught.

Gravity is not caused by centrifugal force.
Gravity is not caused by us spinning.
Gravity is not caused by our magnetic field.

Gravity is caused by one and only one thing and that one thing is called mass. It is called gravitational mass to be precise.

There are two kinds of masses: inertial mass and gravitational mass...and as far as we can tell and as far as Newton can tell, they are the same.

Now this means that things have gravity JUST BECAUSE they have mass.

Gravity is a force of attraction (meaning it will pull two bodies together) and a numerical relation is given by Newton's Law of Universal Gravitation.

Remember that, gravity has nooooooooo meaning if we only had one planet in the entire universe and no other object. You need two objects to have a force of attraction between them.

The Earth has gravity just because it is matter, just because it exists and Newton showed us that ANY two objects with mass will be attracted to each other through gravity.

Yes, this means that at this instance you yourself and the earth are interacting. The force is your weight. You are pulling the earth towards you and the earth is pulling you towards it self.

The only variables in the equation are the two masses and the distance between them. The smaller the distance between them , the more powerful the force of gravity is between them.

The reason we don't notice it here is because your mass compared with the Earth's mass is veryyyyyyyyyyyyyyyyyyyyyy small, so the Earth moves you a considerable distance but you almost don't move the earth.

So if you had something equal, like if you took the sun out, and put Mars and Earth next to each other, they will BOTH pull towards each other and they will meet in the middle.

Since Pluto is far away, Pluto feels a much smaller force of gravity from the sun then we do here at Earth.

Now you should ask well, how does this thing gravity travel. The answer is we don't know (yet) how does is travel but Newton thought it was infinite speed and then Einstein said the force of gravity actually moves at the speed of light (which felt like infinite to Newton obviously).

Something called Gravitation waves have been predicted and have been one of the most sought out things in all of science. But the problem is we know that IF these things called gravitational waves exist, then they must be VERY weak which makes them really really really hard to be detected.

There are several experiments (some very expensive ones) going on around the world to pick up these gravitational waves.

To answer your second question, can gravity be created artificially (I am assuming you mean for something without mass or extra gravity than our mass actually creates like to use in space or something), the answer is that NO, there is not really a good way to do it yet...mainly because we don't really understand why does it exist in the first place and how does it work.

Artificial gravity can't be produced but the EFFECTS of artificial gravity can be produced by things like centrifugal motion (spinning a ship really fast to make them feel like they are in a gravitational field) but that is not very practical and not a good idea in general.

Answer 4

All mass has the property of gravity. Consider the following experiment: two lead spheres are mounted at the ends of a brass rod; the rod is suspended from the center by a quartz thread so that the spheres balance. The position of the rod is carefully measured. Now two more lead spheres are brought in, placed in fixed postion close to but not touching the other two. The gravitational attraction between the fixed spheres and the rod-mounted spheres will cause the rod to turn slightly, demonstrating gravity. This experiment was actually done, for the purpose of measuring the gravitational force, and hence determining the mass of the earth.

Answer 5

Combination of mass and density. Higher density objects have higher gravity, lower density have lower. Same with the mass aspect. Everything that is matter has a gravitational pull, but the largest item wins the tug-of-war. Hence, we are all stuck on Earth until we create a force stronger than gravity to remove us (airplane, rocket). You cannot create gravity, per se, but you can increase an objects density or mass to make it have more gravitational pull, but not enough to do too much to anything, really. If you could erase gravity, you'd have a great market to sell it to, because everyone would weigh less that way. Cool!

Answer 6

Every mass in the universe creates gravity. You create gravity. The problem is that it takes a LOT of mass to create an appreciable amount of gravity. To measure the gravity of ordinary sized objects is a very delicate experiment since they are small enough that the gravity is minuscule. So, unless you are going to put a mass equivalent to a whole planet in a lab, don't expect to get the same type of effects.

Answer 7

Gravity is the force of attraction between all masses. It is not electromagnetic, it is not centrifugal force.

A planet gas gravity because it has mass. More mass means more gravity (Jupiter). Less mass means less gravity (Moon).

Today, gravity can not be "created" in a laboratory. The gravitational force can not be manipulated with any existing technology, and there is no solid theoretical theory suggesting that it is possible.

Answer 8

No one really knows why gravity exists in the first place. It is simply a force which is taken for granted. Everything with mass (weight) has gravity, even you. However, gravity increases exponentially as mass increases, so massive objects (like the Earth) will be able to hold smaller things on them
.

Answer 9

add "String Theory" to the gravity of Newton, then add Einstien's input, and quantum mechanics too. In string theory (or at least what I can gather from the information I tried to comprehend) is combinations of tiny, tiny bits...some with almost no mass...and others with no width, but very long, others with more than 3 dimensions...all holding everything together...The theories of gravitation may just be a way we can understand a much more complex inter-relation between everything, gravity may just be a reflection of what these teeny strings are doing (so small, yet doing all) ...holding everything together under a sort of vibrating potential. They call it the theory of everything

Answer 10

There are four fundamental forces in the universe. Gravitational force is one of them. Any particle or object with any mass at all has gravitational force, the greater the mass the greater the gravity. It is theorized that gravity is made up of particles called gravitons.