Can gravity be used as a means of propultion?
147880
>>>Can gravity be used as a means of propultion?\n\nIt can and it is. Have you ever seen a flying squirrel? Or a petrel diving on a fish? They are using gravity as a means of propulsion. \n\n>>>>>For instance if it is possible to create a device which "bounces" off of gravity. \n\nYou can’t ‘bounce off’ gravity. Gravity is an attractive force, not a repulsive. \n\nThe suggestion is nonsense. You might just as well ask whether you can stand at the top of a well and use the hole to fall up to the sky. \n\nOr maybe ask whether you can use the negative speed of a stationary vehicle to get back where you came from. \n\nIt makes no sense in a  ‘sunbeams trapped in a jar as a nightlight’ kind of way.\n\n\n>>>>>somebody said "gravity is an attractive force"\n>>>>> therefore it is a force... so what about the concept >>>>> of anti-gravity?\n\nThat's way outside my ability to comment on. Anti-gravity depends on the production of anti-gravitons. We don't even know if gravity is caused by gravitons yet, we've never seen one. We've ceratinly never been able toproduce an anti graviton. It's all science fiction stuff. I gather it's possible in theory if certain theories are correct, but in practice.....
177689
No, you cannot simply remove gravity from a specific place.\nHoweverkm you can remove the sensation of gravity (for example, when something is free-falling), but gravity is still very much there effecting the object.
910319
Sure, it would require some force in the up direction, like a parachute.
21499
If you were able to create a device that created a strong enough gravity field to suck in light, it would have the power to suck you in as well.\n\nSo, THEORETICALLY, it could be possible to construct such a device, but turning it on would be fatal.
426889
Antigravity, but that hasn't been proven.  Magnetism works when you have two magneticaly charged objects.
1148300
All space garbage should be recycled and composted into an ecosystem. Thats the complicated set of chemistry questions that goes wtih that particular problem.\n\nUsing large enough diameters and centripetal force we can generate strong enough and stable enough pseudo\ngravity to compensate for that problem. A chemical problem with a civil engineering fix.
304127
Well, I can see and measure the _effects_ of something that we call gravity, but as to there being a substance/force/action called gravity existing, since we can only measure it indirectly and not yet generate or manipulate it*, then scientifically speaking, there is no reason to believe in gravity. \n\n * Although NASA has tried successfully - See reference.
981532
If you assume it is possible and of course it isn't but.... \nIf we also assume that there is no terminal velocity and that our momentum would take us past the centre and carry us to the other side. our velocity would be zero at the start and at the end and would reach maximum at the centre it would be V=(T x G) / D where V is velocity T is time G is acceleration due to Gravity (9.8 metres per second per second) and D is distance (12,756.32 kilometres). By moving the various components in this equation you should be able to find all the needed figures. The total time would be determined by found by finding the time needed to reach the centre of the Earth and then doubling it as the time needed to decelerate is the same as acceleration
208514
Yes, anything with mass generates gravity.  Gravity will only effect things which have mass, so the fact that you are stuck down means you have mass, and thus gravity.
667915
All mass produced a graviational field. The strength of that field depends on the amount of mass and how far away you are. So, yes, you produce gravity. But the whole earth only produces enough to counteract a smallish magnet, so you produce far, far less. A spherical mass like the earth or sun acts as if all the mass was concentrated at the center.\n\nIf you study some basic physics, you can learn about most of this. It turns out that you can calculate the orbits of the planets knowing the mass of the sun, how fast they are going, and where they are. There are small changes from the other planets because they have mass also (just a lot smaller than that of the sun).
463808
In order to combat gravity, we would need to be able to understand what it is. At the moment, we don't. If we did, it still would be a tall order to mess with the field of a whole planet. Assuming we could "stabilize" gravity at the quantum level, whatever device we invented to do this would undoubtedly require huge amounts of energy.\n\nA much easier method would be to install a system of shock absorbers and hydraulics underneath the floor. Controlled by a computer, these could make up for some weakenings in the field and simulate to the human feet an equal field. This wouldn't actually solve the problem, just treat the syptoms. The air pressure of the cabin could also be increased to press our feet down on the ground more, but if we mess with this too much, we will implode. Also, there is the idea of placing a large verticaly aligned doughnut-shaped cabin to produce "gravity" in the form of centrifugal force, but this would be extremely impractical and require a lot of digging. I hope this helps, because until we have Artificial Gravity, there isn't really a lot that can be done. Cool question, though.
950911
At least at current technology level this is impossible (to my knowledge). I'm a physicist from Finland, and I was a bit amazed when I read this question; I had never heard that scientists in Finland have claimed to have made an anti-gravity drive. So I took a quick look what Internet has to say about it (after I couldn't find an article from J Phys D, where this should have been published according to some Internet sources). This sure smells like a hoax; the paper was withdrawn, and every Finnish scientist mentioned in conjunction with this case has denied their participation; in fact nobody seems to know what this is all about. Only guy who has said anything is this one Russian guy (Dr Eugene Podkletnov), and in the end he was the one requesting the withdrawal of the paper. A whole description of the aftermath of this Sunday Telegraph article (where this was discussed) can be found from http://www.enterprisemission.com/antigrav.html (the end part, first is the article itself).\n\nSo, there's a lot of BS going on in this anti-gravity / inertialess drive field. There may be something in maybe 1% of those "studies", but I wouldn't take too seriously anything I read from the web about these things... When something happens, the scientific community will start buzzing. At least I will notice it (I have to follow journals and media about these things because of my work); there's some movement every time a new hoax appears, but that movement stops at the point where other labs try to repeat the experiment. If something new comes up, it will be heard in every media, not only in Internet.\n\nHowever, to answer your actual question, "Is it possible to create an anti-gravity drive that could be used for space propulsion?", I would say that one day it could be possible. There's research going on, and even though some people think it would contradict Einsteins general theory of relativity, I still think it could be possible.\n\nAbout alien spaceships... eh... well, I would doubt their existence. An extraterrestrial intelligence would surely show up first to all hillbillies and mutilate their cows for research? Or play around and show spectacular light shows flying around just for fun? Of course that's not impossible, but I would see it highly unlikely...\n\nDuring my quick look, I found one nice, interesting old article of wired.com: http://www.wired.com/wired/6.03/antigravity_pr.html . I think I'll read that one through...
324067
No. Gravity has to do with the mass of objects--you have some too.
227550
If the question is: If there a machine that can create the sense of weightlessness.\n\nYes there is. That's the kind of machine the astronauts use to practice.
346914
Yes, especially forward at a rate of 1 sec = 1 sec.\n\nI also believe that other rates are possible depending on velocity and proximity to sources of gravity.\n\nI also would like to believe that it can be reversed, but that's harder to swallow due to paradox effects.
1152217
Yes since it would reach it's terminal velocity after a few feet. &  DUE TO THE DRAG IT WOULD NOT ACHIEVE THE SPEED OTHERS are THINKING IT  would ACHIEVE.Given that air is present .
1000866
that's why mass is not wieght, it is not dependent on gravity. so yes