Gravity???

[jschaef5]

I just don't get gravity. How does it work. Does anyone really know... I would like to hear what some of your thoughts are on how gravity works and maybe you could link me to some good sites that explain some theories on it.<br /><br />I don't get how gravity can affect particles that are miles away from eachother. And how a feather and bowling ball drop at the same speed (if u don't count air resistance). Shouldn't the feather drop slower because it has a smaller mass, or is that irrelevent because the relation ship between the ball and earth and then the feather and earth are so clsoe that it is almost the same. Its so different in comparison to magnetic forces. And how does gravity work at small scales, like does it effect the electrons in an atom? The mass of the electron compared to the middle of the atom should be somewhat comparitive to a satalite around earth when comparing masses.<br /><br />Gravity seems too mysterious but so basic and simple. it almost seems like there should be a simple way to explain it like magnetism. <div class="Discussion_UserSignature"> </div>

 

[bbk1]

Thank you for starting this thread. I'm just as puzzled as you. Maybe some of the informed guys here will attempt to answer some of your questions. I will be interested to read some responses. <br /><br />I would like to add one more question: Does the speed of planet rotation have any effect on gravity? That's does gravity increase or decrease with the speed of rotation?

 

[kmarinas86]

The graviational force does not change given that you are the same distance from the gravitational center. However it is the centripetal (or centrifugal?) force that makes you lighter on the equator than the poles. However, there are other factors, like magnestism? and such, that would alter the strength of the graviational field. I heard somewhere that in India, the acceleration due to gravity is less also for something other than the spin of the Earth.

 

[bbk1]

The question is what are the factors that when combined create this gravitational force, that's how is gravity created? It seems that the whole universe is held together by gravity, so how come no one yet discovered how it's generated! <br />The gravity force varies with the mass of the objects, the greater the mass the greater the gravitational force. So does gravity originate from within objects or is it some external force? Is there any materialistic proof that gravity does exist or is it hypothetical force to explain what's holding planets together. Does gravity operate on objects in vacuum? That's if we placed two small objects in an enclosed vaccum container whill they still exert gravitational force on each other? <br /><br />.

 

[jjkeighe]

Force of Gravity = GM1M2/R^2<br />Acceleration Due To Gravity = GM1/R^2<br />G= Gravitational Constant of the Universe = 6.67300 × 10^-11 m^3/ [kg * s^2]<br />M1= Largest Mass/Planet/Mass of reference<br />M2= Smaller Mass/person/object<br />R= Radius from center of M1<br />Earth Approx 9.8125<br /><br />Gravity can be affected through several factors:<br /><br />1. Amount of mass in a specific area. If a mass of 1Kg covers an area of 1Km^2 then the gravitational force will be less than that of a 1000Kg mass in the same area. Also the 1000Kg mass would be a greater force in a smaller area due to the attractive forces of the combined atoms.<br /><br />2. Distance from the Reference Mass. If you stand on sea level, the apparent gravity will be greater then standing on top of Mnt Everest. due to the fact that you are now farther from the centre of gravity. If you were to stand in say Death Valley(below Sea Level) you then have to take into account the amount of mass above your current position which nullifies any extra apparent gravity giving you roughly the same force as at Sea Level. This can be done through a series of calculations that take pages to work out.<br /><br />There are a few other things but I haven't bothered to look anything up in my textbooks from university.<br /><br />Other Facts about Gravity and Space. When two large masses interact there is a point where the attraction of both masses on an object Nullify. This point is known as a LaGrange Point.<br />Gravity Can warp Space, light and apparent Time. ie Black Holes.<br /><br />I will post more after work today but I need sleep so good night.<br /><br /><br />What is the speed of Dark? Why? Because Dark is there before light?

 

[Saiph]

The exact cause of gravity is unknown. Actually the exact cause of any of the four fundamental forces is unknown (strong, weak, electromagnetic and gravity).<br /><br />Gravity seems to work by distorting space-time, or can be considered to operate via a "field" of force. This field exerts a given force, in a specified direction. When a particle is in the field, it "feels" the force, and acts appropriately.<br /><br />This field, or rather changes in it, propagates at the speed of light (or close to it).<br /><br /><br />Thats the short version. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[siarad]

Before the big crunch I started a topic on how gravity can escape a black hole 'cos it seemingly shouldn't have a large pull. I was sent to a site saying gravity was a product of space but then wanted it both ways in saying gravitons can escape. However I look at it, BH gravity makes no sense. If gravity resides in mass & as been shown to travel at C then it can't escape but we know it does or BH would be gravity-less. If gravity resides in space then we know it enters mass by just going down a mine where we don't become weightless. Having said that it seems reasonable to assume a BH will be consuming 'space'.

 

[zavvy]

<font color="yellow">I just don't get gravity. How does it work. Does anyone really know...</font><br /><br />Nope... nobody understands what gravity is or how it works. If anyone tells you differently, they're lying!! <img src="/images/icons/tongue.gif" />

 

[omegamogo]

There was a huge topic with a lot of good posts about gravity here some time ago, I think I still got it on my Pocket PC, But if i find it i'm going to need some place to host it.

 

[jitte]

I've got a page on my site about how gravity relates to orbital mechanics and spaceflight, if you're interested. It won't answer all the questions you've put forth, but covers the basics fairly well.<br /><br />The name of it is Gravity Rules.<br />http://www.uberkomplex.com/

 

[nacnud]

We can describe the effects of gravity on the macro scale throught General Revalivity. In most cases newtons gravity is a good enough approximation to this, but as to how it works is still a mystery.<br />

 

[nikshliker]

just to repeatwhat almost everyone else said,gravity is an unexplainable force in our universe. It also isn't the strongest unexplained force either. the even more indescribable forces strong and weak seem even more mystifying. Gravity may puzzle us for as long as I live, for I don't see any new theories that are coming up that even try to support the macro and micro effects of gravity, let alone the case of a BH. We can however describe how the objects interact with eachother which I think may be just as good. The gravitron idea is a vague one also. I don't fully understand its notions but to me it seems incorrect to try and create a heoretical particle to help describe it. gravity is to one its own just as strong,weak, and electromagnetic forces are. An even better question would be about the strong and weak forces, for they will present us with a useful form of energy. the analogy of saying satellites in orbit are the same proportion as electron in orbit is false. to put the atom in proportion, I live in wisconsin so..., if a pea were the nucleus then in the badger stadium the smallest spec of dust in the highest seat of the stadium would represent the electron. There are much more curious forces involved in the atom than gravity... <img src="/images/icons/wink.gif" />

 

[jschaef5]

The best way i visualize gravity is that bowling blal on a sheet of rubber demonstration, how it curves space around it to pull everything else in. <div class="Discussion_UserSignature"> </div>

 

[igorsboss]

I'm down wit' it

 

[bbk1]

jitte<br /><br />Thank you for giving link to your website. Very informative and well structured explanation. As you indicated it'll not expose the unkown behind gravity or where/how it's generated but your write-up does give a good background and in-depth explanation of how it works.<br /><br />Thank you for sharing.

 

[jitte]

Thanks a lot bbk1, that makes it all worthwhile for me. <img src="/images/icons/smile.gif" />

 

[siarad]

Yes good site thanks. A quicky, you've a typo in penultimate para 'evevator' or something not elevator. <img src="/images/icons/laugh.gif" />

 

[jitte]

Thanks for letting me know siarad, proofreading is the hardest part for me. <img src="/images/icons/wink.gif" />

 

[siarad]

I did a little proof reading for a local paper (galleys) about 40 years ago. They're continuous like speech, to save wasting paper with gaps, so are very hard to read. I guess that's why we can read four times faster than hear as the written words are already split.

 

[siarad]

If gravity is a force it seems peculiar to me. If the speed of a force pushing me is faster than my movement then I feel it but gravity moves at the speed of light yet I can jump in the air & upon falling can't feel it's force despite accelerating. Only when totally resisting it, does any feeling happen, just ask the astronauts <img src="/images/icons/laugh.gif" />

 

[dan9678]

Here is my crazy idea about gravity:<br /><br />I think acceleration is a property of the relationship between mass and spacetime. In other words, space itself ‘resists’ a mass’s change in velocity. The two are inseparable. Also, there is no discernable difference between the acceleration due to gravity and acceleration due to a change in velocity. It is because of this, I think the space around all matter is continuously ‘falling’ into that mass. If you happen to be falling towards that same mass, you feel nothing because you are moving along with the flow. Somewhat like a boat drifting down stream. On the other hand, when standing on the surface of a mass, you do feel this acceleration because your body has to exert a force to resist this flow. <br /><br /> -Dan-<br />

 

[neutron_star6]

Hey siarad yea I remember your topic about the big crunch and about how gravity can escape a black hole I thought it was very interesting and Im pretty sure i posted on it as well. Anyways as you get deeper and deeper into the question and find one answer theres always more in front of you which this in a sense is. But on the other hand so is every other question that has to deal with any type of science. BH does consume space and warps time somehow just not in that sense. I read it a while ago on another post either that or i read it in one of Stephen Hawkings books.

 

[nikshliker]

gravity seems to be an acceleration al its own for the fact that it warps space-time so much. I suppose the GR you could also say accelerating in a space ship neer the speed of light would also warp space-time in your frame of reference also but it seems different with gravity. Just what siarad said before, you feel the acceleration when you are inn a space ship in space but when u freefall you dont....<br /><br />however, the only reason you feel it in the space ship accelerating is because tthere is a resistant normal force pushing u along at that acceleration. That same normal force is holding you from falling into the middle of the earth. It seems to be all the same except for that fact that large bodies warp space-time. I truly dont understand this differencec. any one that could help me out with this I would give a cookie to.: why des space-time not warp if you accelerate in a rocket ship?<br /><br />whoever answers this will most likely say "it does" please give an explanation why. I will think through this on my own also and might come up with an idea

 

[nikshliker]

maybe it is because the ship is moving... i truly have no idea and this sucks.... <img src="/images/icons/frown.gif" />

 

[siarad]

My point is, there is a discernible difference. Acceleration due to gravity is indiscernible. As a young kid we played the game of weightlessness, whereby we ran upstairs & jumped out of the bedroom window, we were small enough not to be hurt by the fall. Now running up the stairs I could feel my change in velocity but in the free-fall I could not. Imagine rocketing to-wards the sun & cutting the motor, suddenly you're weightless. Well you could feel the acceleration of the motor 'cos you hadn't reached it's speed. Now you're accelerating to-wards the sun but feel nothing despite being nowhere near it's speed, that of light, so why not? I'm seemingly not <i>going with the flow</i> which is C. On earth we are accelerating to-wards the sun but don't feel a thing despite it's huge pull. I don't know of an instrument that can measure G in free-fall. If I was on a spaceship born during a 50 year trip to a distant star & all crew had died, my experience would not include gravity so any science I managed to think up would not include it. The exception being, perhaps, by looking out of a window in wonderment at motions of stars.