can gravity act in a vacuum? explain.?
98562
Yes!  Gravity has nothing to do with air, or the lack there of.  People tend to accociate vacuums with the absense of gravity because of the vacuum of space.  However, gravity is what keeps the moon orbiting the Earth and the Earth orbiting the sun, even though there is no air in space.
323244
This is conceivable, but only in a very low/no gravity environment.  Thanks for your thoughtful question.
119146
No, i dont think gravity can pull in multiple directions, which would be neccessary for something to expand.
373232
No, A BIG NO. even on outer space, the gravity is NOT zero. It is very near to Zero (maybe like 0.0000000000000000000001 or something), but never exactly zero. This is because gravity has a range of infinite, i.e. the effect of gravity reaches to every place in the universe and even more. However, it is also known that gravity's power is inverse square to the range (S/4*pi*a_huge_distance^2 = almost 0, but never exactly 0, unless S=0 which means there is no gravity source), thus after a certain distance, the effect of the gravity is negligible and won't affect almost anything. BUT it is not zero. There is no point in space that have completely zero gravity, if there is at least one gravity source in that space, even if the gravity source is placed very far away from that point or even if the gravity's power is very small.\n\nThe gravity is similar to light in this way of infinite range. If you fire an ideal laser (one that would not spread out even minutely after great distances), and you stand on a very far away point from the laser, you'd still be able to be pointed by the laser. Light is also a force that have an infinite distance. Light however, is not exactly the same as gravity.
705496
assume that just for 1 second gravity goes off and comes back, what will happen??? is it possible??? no funky answers please. genuine replies are appreciated.
1174809
It actually follows the laws of gravity. Even when gravity is present, it is possible to reach a velocity that can escape gravity.\n\nTechnically, with gravity the universe should collapse back upon itself and the big bang would occur all over again. However, gravity is one of the weakest forces in the universe. With that said, it has been measured that the universe is expanding and accelerating at a rate that exceeds the gravitational forces required to initiate the "big crunch."\n\nThere are two schools of thought right now. One is that the universe will continue to decelerate but never completely stop or collapse upon itself. More recent theories have stated that the universe appears to be accelerating.\n\nAs it stands now, I would say that it is safe to say that the odds are extremely low of the universe collapsing back to a singularity.
196829
The crucial question is whether the universe is dense enough to slow things down enough before everything expands away. Yes, gravity exists all through the universe (at least what we can see). In fact, it was Einstein's theory explaining gravity that first predicted the expansion of the universe (although Einstein legislated that solution away by adding in another term). But if the density is too small, the velocity of expansion is already above the escape velocity and so expansion continues forever.\n\nEven more important, we have recently found that the expansion is accelerating! This means that the term that Einstein put in actually exists, but not in the way he expected. Nobody really understands what is happening with this 'Dark energy'.
618522
Yes, a gravitational field can and does exist within other gravitational fields.  All masses in the universe exert an attractive force on all other masses in the universe through a force known as gravity.  Gravity is a vector quantity meaning it has a direction.  These forces act in different directions and cancel each other out. To keep from getting too technical take this example.\nYou are standing on the surface of the Earth, within its gravitational field.  The Earth attracts you to its surface because of the force known as gravity. You, having mass, also exert a force of attraction on the Earth. The reason you do not notice your attractive force on the Earth is that the earth's mass is so much larger than your own. The earth acts a force in one direction, you act a force in the opposite, the result is the net force in the system.(You bening pulled toward the larger mass, Earth)\nThis can be proven mathematically with the formula \nFg=[G(me)(m)]/d^2\n\nG being the gravitational constant, multiplied by me, representing the mass of the earth, and multiplied by m, representing your mass, divided by the distance between you and the earth's center of gravity squared.
862081
No one knows for sure what creates gravity, we only know that it is a force since it causes an acceleration, and what the conditions are for it to be present; which is any amount of mass. Everything creates gravity, including you and me, but it is only noticeable with large masses such as the earth, sun, and well, black holes.  If we knew what creates gravity, a whole lot of other questions could then be answered, such as if time travel is really possible. A black hole could suck the the sun in but that is seriously unlikely to happen since one of any meaningful size is hundreds of light years away. There are however very, very, very tiny black holes that likely occur naturally in our upper atmosphere as solar particles collide with our air. Next year in Europe, an experiment at a particle accelerator will attempt to prove the math behind this to confirm the mini-black holes' existence. Bottom-line... after next year, we might be able to tell you something more about gravity and what creates it.
801582
No, physicists have always known that gravity is the one "force" that we really still don't understand. Now it is true that at macroscopic or large distance scales, we understand gravity very well through Einstein's General Relativity Theory. But at the quantum level, the scale of sub-atomic particles, we have no idea how gravity works there. And the most interesting thing is that when we try to probe and understand gravity at the quantum level, we find that we have to abandon all our currently understanding of space and time, as well as the notion of 3-dimensional space.
280881
There isn't gravity "on the moon"; gravity is a property of objects. And the self-congratulatory tone of the guy who says you must have realized that your premise is wrong betrays the fact that his answer is a tautology. The only reason the moon exerts a gravitational pull is BECAUSE of its mass. If there were no mass, there would be no gravity in the first place. One can overcome the force of gravity, but saying that the moon would fly apart without it doesn't make any sense. Gravity will be there no matter what. Other forces can overcome it (otherwise the Apollo astronauts who landed there wouldn't have been able to leave its surface), but gravity can't be turned on and off.  In a less dramatic way, one could see the astronauts picking up rocks, or kicking up dust. The kinetic energy of their movements was enough to overcome the force of gravity on the moon until the dust settled (which it does much more quickly than it would on earth, since the dust doesn't encounter friction with air).\n\nNo one knows exactly what gravity IS, by the way. Some physicists believe that it results from the warping of space-time; others continue to seek out a particle (the "graviton") that is the conduit of the force (kind of like "photons" are particles of light).
514578
Yes, Gravity works everywhere, but there are some kinds of gas that result lighter than gravity so they float or even goes up.
324067
No. Gravity has to do with the mass of objects--you have some too.
881854
gravity and any type of electromagnetic radiation r two DIFFERENT things.if a region has a gravitational field then it can have a electromagnetic field at the same time.Both dont interfares so cant cancel each other.Look at it like this,if a 1 kg particle is in electromagnetic field , it will experience grav. force due to its 1 kg mass and electromag. force due to electromag. field present AT THE SAME TIME BUT BOTH DONT(RATHER CANT) CANCEL EACH OTHER.\n\nPlanes can be lifted by electromagnetic radiation if we made some electromagnetic radiation producing thing on earth and equip plane with a electromagnet also. But due to huge size of plane and different geographical conditions it is both difficult (read impossible) and impractical to implement and that when we can fly them much easily.\nBut the upper method is in use already in 'maglev' trains
1168282
I read a book about this.  I don't remember the title, but this guy claimed he had it.  He claimed that all atoms are expanding at the same rate.  This is what causes gravity.  More massive objects expand in more space in less time than less massive objects.  \n\nI don't remember the details of the rest of the fields, but they all related to this expansion of atoms.
297450
You are open to the absolute vacuum of space. Now if you understand vacuums the tighter it is the higher potential pressure on anything containing matter. Therefore when exposed to a vacuum all the fluids of your body will rapidly escape with the thin layers of flesh not even slowing them down. Think of a water balloon that has been overfilled.
450131
As far as I know, they are still not sure as to what creates gravitational force. If they determine the source, one might negate it to experience zero gravity anywhere.