How can gravity be concentrated into a small radius?
915872
Gravity is defined in a new term.  That is the latest report\n    of the atomic relativities of the quasar versus the quantum\n    in an isolated directive.  Defined by the mineral interactions.\n    What?  Gravity has the interactive quantities added to the\n    average force of one planet attracts to another Plus the ionic\n     pentanmeters(depends on the substance with conditions).\n    So gravity is present in all materials if left in free space, or put\n     into orbits, or put on a plane.  This last set is the theoretic\n     gravity of space infinitives to the nth degree, showing that all\n     materials have the origin of gravity values as established at\n     the desk of the elements chart, and its properties.  The flight\n     of planets is a true measure of gravities, showing such things\n     as anti-gravity points like in a space capsule.  The interaction\n      really never out drives the elements chart standard.
759224
Gravity pulls all mass towards a central point.  When there is enough mass the gravity is so great that it overtakes the other forces that hold the structure in another shape.  If gravity is pulling everything towards one point it will make everything equidistant from its center.  If the Earth had a very large lump on it, for instance if you stuck the huge volcanoe Olympus Mons on the Earth, the Earth's strong gravity would pull that mass towards its center and flatten it out.  Olympus Mons can exist on Mars because there the gravity is less (since it is a smaller planet).  If the Earth were square (or a cube rather) the corners sticking out would gradually be pulled in towards the center.  \n\nInteresting note: this is one of the circumstances that a planet and dwarf planet must meet to be called one of those names.  It must me large enough that its gravity is so great that it has evened out its surface into a more or less spherical shape.  There are of course many asteroids and comets that are very oddly shaped because they are small enough that their mass isn't able to overcome the structure of the material.  Similarly if you put a human in space, they will have their own mass and gravity but since it is so small they wont collapse into a ball-- the gravity is unable to overcome the structure of our bones and muscles.
960972
The denser the black hole, the larger it's event horizon would be.\n\nApplying the Einstein Field Equations to collapsing stars, German astrophysicist Kurt Schwarzschild deduced the critical radius for a given mass at which matter would collapse into an infinitely dense state known as a singularity. For a black hole whose mass equals 10 suns, this radius is about 30 kilometers or 19 miles, which translates into a critical circumference of 189 kilometers or 118 miles.
1005047
this would work only over short distances.  the problem is that gravity decreases as one over the square of the distance, while magnetism decreases as one over the cube of the distance.  thus, magnetism would get weaker faster than gravity.  also, magnetic field structures tend to be much more complex than gravitational fields.  you would have to understand the magnetic field of the planet extremely well for it to be of use for something like this.
300802
if the point is big the gravity don't effect it much but if it is small gravity will effect it i forgot the whole explanation though \n\nyou could try this link
110744
Short answer: usam da inverse square law Jar Jar!\n\nLong answer:\n\nNewton simplified things by picturing all of a planets mass gathered in a single point in the center of the planet and the surface as a point on a certain distance from that center of mass. So the gravitationall pull (F) on a body (m) at a distance (r) from the mass (M) can be calculated using this equation:\n\nF=G*((M*m)/r^2)\n\nwhere G is the gravitational constant (6.67 * 10^-11 Nm^2kg^-2)\nEarths (equatorial) radius is 6.378 * 10^6 meters and its mass is\n5.974 * 10^24 kilogrammes\nSo lets test this on a dude weighing 100 kg:\n\n6.668 * 10^-11*((5.974*10^24 * 100)/4.068*10^13)\n==>\n6.668 * 10^-11*(5.974*10^26 /4.068*10^13)\n==>\n6.67 * 10^-11* 1.424*10^13 \n=\n979 N (what I got in my calculator)\n\nSo earth pulls on a guy, with the mass 100 kg, with the force of 979 Newtons. That means 9.79 N/kg, earths gravitational force (g). This should also mean that a mass dropped from a small height should accelerate at the rate of 9.79 m/s^2. It´s a simple experiment to do but where I am the value of g is actually 9.82. This is because I am closer to the earths center. Earth bulges out at the equator because of its rotation. I am farther north. But still a simple experiment can be done to validate this calculation. \nSo if the earths mass was 3 times greater than g shoud be 3 times greater. Right? You betcha. And I have already shown that moving closer to earths center increases g. Moving twice as far from the center should decrease g by half. Right? Wrong! Now what? We where so close. Oh man...\ng is reduced to a quarter if we increase the radius by 2. This is because of the inverse square law, a very important law in astronomy. It means that the apparent brightness of a light source is inversely proportional to the square of its distance. This also aplies to gravitational fields. Double the distance, divide by 4.\nSo lets put this all together. You should be able to do it yourself by now. I got 734 N or 75 % of the dudes weight on earth. And the reason he doesn´t weigh more than on earth is because of the inverse square law. Eventhough the new world is three times as massive we still moved twice as far away from the center. So take the weight of your astronaut, multiply by 3 and divide by 4.
375266
Gravity is a force that accelerates two masses directly towards each other. In order for the masses to not simply crash into each other, one of the masses must have some nonzero velocity relative to the other mass that is not directed along the line between them. \nAssume one mass is larger than the other. It takes some time for the smaller mass to hit the larger mass under the pull of gravity. If we give the smaller mass a velocity perpendicular to the line between the two masses, the mass may "miss" the larger planet before it falls all the way to the surface, and continue to do so. The range of velocities can make this continual freefall take shapes from a perfect circle (the perfect tangential velocity, which has almost zero probability) to ellipses, and with high velocities from parabolas to hyperbolas.\nA velocity too small will simply increase the amount of time before the planets collide, these are spirals.
365615
Have mass and occupies space
151142
The gravitational attraction is felt between any two objects (assuming that they have mass).  Gravitation is the weakest fundimental force, so the attraction between two 60 kg persons sitting 6 meters apart is 6.67 nN.\nTHe bad news is that you can't prevent this force from acting, however it is a very small force.  I don't think you need to worry about gravity as the source of your 'physical' attraction.
644891
No, because gravity is inflicted by the mass of an object... and we have a very massive object near by that will outweigh any gravity caused by a humble golf ball or a slightly proud bowling ball: it's called the Earth.\n\nBasically, gravity is a force of attraction, so a large object will attract a small object. That is what keeps the moon orbiting the Earth, and the planets orbiting the Sun. Even here on Earth objects are attracted to each other, but the Earth's gravity makes that force almost impossible to measure or detect.
914835
acceleration due to gravity at a distance 4 times the radius is GM/(4R)^2 Where M is the mass of the earth . that is the answer is g/16.
34520
Gravity shapes objects.  If an objects mass is over a certain threshold then gravity will be strong enough to overcome molecular forces to "mold" an object.  Most asteriods have masses that are too low for this however planets and most moons are massive enough.  \n\nWhy a sphere?  This is due to the inverse radial dependance of the gravitational force.  In order words at a given distance from the center of mass distribution the force of gravity is the same.  This type of shape is a sphere.
436928
If the Earth's radius were bigger, and the mass of it stayed the same, then you would weigh lighter.  That's because with a bigger radius, you're farther away from the centre of gravity, therefore less pull.  If the mass change, then the situation would be different.
1093836
Centrifugal force and gravity.
302984
I Dont know what sumink is, but if you want to increase the density of any object while keeping its mass constant, its volume has to become smaller (more compact, more dense), hense its radius would decrease as well.
823207
gravity is a special case  of gravitation.It is the force by which earth pulls a one kg object towards it.\n\nie g=GM/R^2\n M=mass of earth\nR=Radius of earth\n\nnow force acting on a object  of mass 1 kg at a height h(from earths surface) will be \nf=GM/(R+h)^2\nwe can take out R out of bracket so that (R+h)^2 can be R^2{1+h/R}^2\nNow\nGM/R^2=g\nSo we can easily WRITE it as \nf= g/{1+h/R}^2\n\nThis f is that something we usually write as g'\n\nNow g' can be written as g{1+h/R}^(-2)\n\nFOR NOT TOO SOPHISTICATED CALCULATION\nIT CAN BE REDUCED USING BINOMIAL THEORM TO \ng'=g{1-2h/R}
484173
Smaller than a refrigerator. It would be a single point. The event horizon surrounding it would be another matter.