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What is Gravity?

Large celestial objects such as moons, planets, and stars have enough mass to generate significant amounts of gravitational pull.
Isaac Newton published his law of universal gravitation in 1687.
Galileo made great strides in the study of gravity around the year 1600.
All objects fall at the same rate, regardless of their size.
Albert Einstein concluded that gravity affects space-time.
Gravitational forces keep the planets in the Solar System orbiting around the Sun.
The Space Transportation System, popularly known as the "Space Shuttle", used booster rockets to overcome Earth's gravity and enter orbit.
Gravity gives everything weight.
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Essentially, gravity is an attractive force between objects. Most people are familiar with gravity as the reason behind things staying on the Earth's surface, or "what goes up, must come down," but gravity actually has a much vaster significance. Gravity is responsible for the formation of our Earth and all other planets and for the movement of all heavenly bodies. It is gravity that makes our planet revolve around the Sun, and the Moon revolve around the Earth.

Though humans have always been aware of gravity, there have been many attempts to accurately explain it throughout the years, and theories must regularly be improved upon to account for previously unconsidered aspects of gravity. Aristotle was one of the first thinkers to postulate the reason for gravity, and his and other early theories relied on a geocentric model of the universe, with the Earth at its center. Galileo, the Italian physicist who made the first telescopic observations supporting a heliocentric model of the solar system, with the Sun at the center, also made strides in the theory of gravity around the turn of the 17th century. He discovered that objects of varying weights fall towards the Earth at the same speed.

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In 1687, English scientist Sir Isaac Newton published his law of universal gravitation, which is still used to describe the forces of gravity in most everyday contexts. Newton's first law states that the force of gravity between two masses is directly proportional to the product of the two masses and inversely proportional to the square of the distance between them, or mathematically: F=G(m1m2/d2), where G is a constant.

Newton's second law states that gravitational force is equal to the product of a body's mass and its acceleration, or F=ma. This means that two masses that are gravitationally attracted to each other experience the same force, but that it translates into a much greater acceleration for a smaller object. Therefore, when an apple falls towards the Earth, both the Earth and the apple experience equal force, but the Earth accelerates towards the apple at a negligible speed, since it is so much more massive than the apple.

Around the late 19th century, astronomers began to notice that Newton's law did not perfectly account for observed gravitational phenomena in our solar system, notably in the case of Mercury's orbit. Albert Einstein's theory of general relativity, published in 1915, resolved the issue of Mercury's orbit, but it has since been found to be incomplete as well, as it cannot account for phenomena described in quantum mechanics. String theory is one of the foremost modern theories to explain quantum gravity. Though Newton's law is not perfect, it is still widely used and taught because of its simplicity and close approximation of reality.

Because gravitational force is proportional to the masses of the two objects experiencing it, different heavenly bodies exert stronger or weaker gravitational force. For this reason, an object will have different weights on different planets, being heavier on more massive planets and lighter on less massive planets. This is why humans are much lighter on the Moon than they are on the Earth.

It's a popular misconception that astronauts experience weightlessness during space travel because they are outside the field of gravitational force of a large body. In fact, weightlessness during space travel is actually achieved because of free fall — the astronaut and the space shuttle or rocket are both falling (or accelerating) at the same speeds. The same speed gives the notion of weightlessness or floating. This is the same concept as a person on a "free fall" ride at an amusement park. Both the rider and the ride are falling at the same speed causing the rider to seem as though he is falling independent of the ride. The same feeling can be experienced while riding an airplane or an elevator that suddenly breaks from its normal rate of decent.

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anon942837
Post 108

I think gravity is caused by the compression of time and space.

anon351649
Post 106

Physicists confuse mass and gravity. Everything has gravity but not everything has mass. Physicists are confused about gravity. If they think they've found gravitons, then they are living in a dream world. When a star explodes, does its gravity change or is it simply distributed over a larger area? They're going to discover gravity waves are a myth.

If you believe in Einstein's mass energy conversion then you should be able to figure it out for yourself. We start out with the very simple and move to the very complex. Magnetism can be made to demonstrate both attraction and repulsion. There is no magnetic wave, only electromagnetic waves (energy). But if you move mass, do you create a wave? Think on that for a while.

farmerjim
Post 105

So, are gravity waves like magnetic waves? I ask because magnetic waves push, not pull.

Or, on a personal basis, you are standing facing your partner, you reach out and hold onto his or her belt and you pull your partner into you. That's pulling.

Alternatively, you are standing facing your partner and you put your arms around her or him, With your hands on his or her back, you bring your partner into you. That's pushing.

So, how does gravity manifest? As waves? something else? Or are we still at the wild guess stage and not yet arrived at the scientific wild guess stage? I note there are a lot of polysyllabic erudite statements, but they don't really answer the basic questions I asked.

anon300175
Post 99

To be able to put it all together, one must first completely understand gravity and e-m energy. The first problem you encounter is the visual analogies used to describe them. People seem to take these analogies literally. They are only descriptors of what is actually going on. Another clue. You have to go small in order to get the big picture. If anyone understands, please respond.

anon297679
Post 98

Would it trouble anyone to know that the gravity effect is not constant, nor is it, as we know it, that which dominates the universe? This has nothing to do with religion or deities. It is a simple fact. Does anyone out there understand the physics of what I am saying?

anon282247
Post 96

@elama157: When the 'gravity' light turned on for me, I felt compelled to share some clues, thinking I was not alone. I've seen bits and pieces of brilliance (parts of the puzzle) in a few posts which seem to be from ordinary people.

Surprisingly, I have yet to see the same in posts offered by those who imply a greater knowledge of science, and, in fact, their prime talent appears to be dumping on the rest of us. What have these elitists and the scientific community produced? Grand Unified Theories (GUT) that are just bad science fiction.

Have you noticed that, the more educated the mind, the more complicated the 'gut' solution appears to be. The answer is all around them and yet they do not see. They have been measured and found wanting.

anon266212
Post 95

No such thing as gravity. It was made up. The apple doesn't fall from the tree from gravity. It falls

because its stem rots or the wind blows it off. Or something else wants to eat it.

anon257598
Post 94

Einstein discovered that one body travels around another because of warped space. Why then, is it still being taught that bodies attract one another?

anon253545
Post 93

The effect and "feel" of gravity and gravity of a rotating space-station, is the difference between one set of atoms/molecules, en masse, traveling at motion, trying to `pass' through another set of atoms/molecules, but can't (could say the latter is like a mirconet across a river, and what is travel `on' the river, is held up on the micronet).

Secondly, actual gravity, e.g. of a planet's surface, is related to the "skin-deep" depth of atoms in the surface (of all "frozen ice" solid "matter" phase), which their protons are mostly shielded by anti-gravity outflows of electrons (this is also were natural light frequencies form, hence, electromagnetic spectrum, of waves, mixed, apparently fairly regular).

As such, all gases/vapours in an environment are all anti-matter gas phase, since these atoms/molecules have their electrons so far from the inner protons that protons gravities inflows are swamped by anti-gravities outflows of electrons.

This is why there is no such as a liquid state, only a transient phase, of in-between motions/transfers. Thus any gravity rate or value (not force, and not pull!) is the result of protons' gravities inflows into every inner atom, that passes out with electrons anti-gravities outflows shieldings.

anon253482
Post 92

The problem with gravity is that it failed to explain how the galaxies stick together. As I understand it, when they originally did the calculations for the galaxies, their conclusions were that the should fly apart because there's not enough mass to hold them together. But that's not what we observed. Thus, we started looking for dark matter/energy to explain the observations and to restore our faith in gravity.

We can't see dark matter/energy directly, but we can indirectly see it. Of course, this all assumes that our theories of gravity are correct.

anon250503
Post 90

As you wrote earlier that astronauts and other experience weightlessness because they are falling i.e., they are experiencing freefall. How is that even possible? When the rocket reaches at certain space it remains on the stable place. And please explain more about earth's magnetic field.

anon241827
Post 87

When, oh when is man going to finally get gravity correct? It is pushing, pushing, pushing.

Oh Newton, oh Gravesande, oh Einstein.

You moved us along but not enough to actually get us over the hump.

Gravity is pushing us down onto the earth yet people are still misinforming their children from birth.

When will this (equal to the Flat Earth falsehood) finally end?

anon240626
Post 86

I came across this by accident. It's like listening to mice discussing nuclear fusion. Kudos to the patient few who have taken the time to try to explain a few things based on actual knowledge. But guys, you're mostly talking gibberish. Go study the subject for a decade before offering an opinion or explanation.

Matter screen gravity? Dark matter pressing down?

Huh?

DavidStatham
Post 84

In the attempt to explain gravity, I have considered that the universe total mass includes dark energy to the amount (with dark matter) of some 65 percent. So space is not "empty" but completely full of invisible particles. They are so small that millions pass through your body constantly without (apparently) doing damage. 

But what if they actually have a push effect on matter such as us as they are drawn into the centre of the huge mass of earth? It would be like an invisible snow storm of incredibly small particles pushing us down toward the centre of earth and thereby creating our weight. It would explain many things in physics.

You can't, for example, shield yourself from the snow storm effect because the shield would have to be so dense and itself would be pushed downward. Many posts have described a feeling of a downward push. We are not metal so it should not be an electromagnetic push like a magnet. Maybe the particles are the missing Higgs bosons?

Please advise if this idea could work or indicate why it can't?

David S., South Africa.

anon231350
Post 82

the answers to your questions are very simple. The-Brain

anon228286
Post 81

I was in the hospital for a month and I had this thought problem that I kept thinking about as I sat in my uncomfortable hospital bed with gravity tugging at my weak body. I thought of a huge centrifugal weight spinning near the bed in a way that countered the gravity that made me uncomfortable. In essence, this huge wheel spinning at enormous speed near me above me would counter the weight of the earth.

Of course, it would have to spin with a force and mass near the weight of the earth to have any measurable affect, but I felt I was on to something about understanding gravity.

anon216128
Post 80

Wow. Just, wow. A gram of matter, whether it is sun, earth, water, feathers, people, whatever, whether it is spinning or still, moving or stationary, a gram of anything has the same gravitational pull as a gram of anything else. At a given distance, gravity is solely proportional to mass. This proportion is known reliably to several decimal places and has been demonstrated thousands of times by undergraduate physics students everywhere. They simply measure the gravitational attraction between small steel balls. That is the classical Newtonian understanding of gravity and while not complete, it is close enough for most of the discussion here. It is enough to understand the basic mechanics of motion for the Earth, satellites, the Moon, etc.

Also, the earth or any object behaves as if its gravity emanates from its center of mass. We are all nearly 4000 miles from the Earth's center. A typical orbiting spacecraft is only another 100 or 200 miles out. Gravitational pull does not magically disappear when something is 4100 miles away from the center of gravity rather than 4000 miles.

In other words, gravity is almost as strong in low-earth orbit as on the surface. Things like spacecraft and the moon do not appear to 'fall' because their orbital motion effectively counteracts the gravitational pull acting on them. That's why they orbit. Moons orbit planets, planets orbit stars, and stars orbit the galactic center. Everything is in equilibrium. Also, if you travel deep into the earth, you now have some mass over your head so the gravitational pull downward is indeed not as strong. The Earth ceases behaving as a point source of gravity. This is a simple, first-year calculus problem.

Einstein's general theory of relativity makes mathematically accurate predictions by describing gravity as an acceleration of matter along curves in space-time, which are disturbances in space-time created by other massive objects. This effect has been repeatedly and reliably demonstrated. Still, it is an incomplete description of what is going on.

No one can say they understand what gravity is on a sub-atomic level because it has not been demonstrated experimentally. The scientific method was invented because it is the only reliable way to separate the truth of reality from conjecture. Therefore, no one can really say they understand how gravity works. That is why we have multi-billion dollar projects like the Large-Hadron collider in Cern.

Also, it is probably impossible to truly understand a fundamental aspect of reality, such as gravity, because by its nature, it cannot be described in terms of anything else.

whiffsofblis
Post 79

"Everything is made of atoms. That is the key hypothesis. The most important hypothesis in all of biology, for example, is that everything that animals do, atoms do." -- Richard Feynman

Since humans are said to be composed of "star stuff," maybe gravity affects us (and our relationships) in more ways than we realize? Yet, how would we ever know, unless we explore what universal gravitation really means?

gravitation
Post 78

More scientists will realize there isn't different gravitation for stars/planets and another for people. Gravity is universal as "The Secret" Law of Attraction.

anon213251
Post 76

I've considered gravity as having an elastic power - I'm thinking on it.

anon208703
Post 74

No one at the present time on earth really knows what gravity is; there are only theories. End of subject.

jtmontclair
Post 72

Gravity is the observed effect of a warp in the space-time continuum.

anon186630
Post 71

Gravity sounds to be peculiar as quantum physics. Ever wonder what happens before the so called big bang? Maybe all matter comes and goes from gravity switching off, possibly slowly, in cycles. This universe could be pulsating with the mysterious cycles of gravity's cycles of shutting on and off. Too heavy for my thoughts.

anon184476
Post 70

gravity is part of god's dream. as we are.

anon166251
Post 69

I think an object needs to be a certain size before it can actually attract objects. the whole - & + attraction and fluid universe makes sense until one says that all matter has gravity. This would explain why moons are able to stay in space and not crash to earth. The moons are big enough, for their particular planet, to have enough gravity and attract enough matter between them and the planet to keep it in orbit. (unless there really wasn't a moon landing, then who knows)

If every object had gravity, then a house-sized bowling ball would attract small marbles to it, right? --fireman0624

anon163112
Post 68

the force we feel is negative space, created by the density of the mass occupying the space. I mean the same stuff the outer space is made of; it is not just a vacuum. It is a medium. We have space in us which is drawn to the center of mass/density which is also the maximum negative space. We have to start thinking of the force being related to space, not just mass density. This theory is my theory.

anon162909
Post 67

Gravity is the reason for the existence of an atmosphere on Earth. It's also the reason why the Moon revolves around the Earth. Gravity is the force of attraction that is proportional to mass. The moon is heavier than air. But why is air nearer to the Earth's core relative to the moon?

Gotham
Post 66

Every time you fly in an airplane you counter gravity. Centrifugal force, acceleration, gravity, there's no difference. Better ask how a ship floats on water. --Robert H.

anon161344
Post 64

please tell me as soon as possible that how can we make ourselves gravity-less.

anon160113
Post 63

why are people weightless on the moon, yet rocks are not?

- anon144955

People aren't weightless. because the gravitational pull (an acceleration) is much lesser than that of the earth, we accelerate towards the ground more slowly. if we were weightless on the moon, we wouldn't be able to walk on it. one step and the force would send us in a straight line out of it.

Gotham
Post 61

Gravity is not a force but simply acceleration. Weight on the other hand is mass and inertia. Which exists in space as well as on earth. This is why a tiny meteorite can penetrate steel.

anon155774
Post 59

Being from a non-physics back ground, i have a problem answering this question. We understand and know how to create a magnetic force. Yet i can find no answer of how gravity is created or exists. a force so strong that the sun can hold objects billions of miles away in it grasp. Yet so weak it doesn't pull mercury to it's death.

I believe gravity is a mathematical condition that has not yet been identified. I would be grateful it someone could explain how a rock creates gravity.

anon148014
Post 58

Why isn't the point of a compass pulled downward toward the earth? Are the magnetic Poles stronger at the north and south points on earth, rather than anywhere else on our planet?

anon147592
Post 57

Weightlessness can be seen as a absence of a support force. Hence why astronauts are weightless.

anon144955
Post 56

why are people weightless on the moon, yet rocks are not?

anon143587
Post 55

Gravity sucks! Astronauts are not out of the earth's gravitational suck. Astronauts are always falling towards the earth, due to earth's gravity sucking them down towards its core.

The only reason the astronauts don't slam into the earth is because they are speeding around the earth at over 17,000 miles per hour. The earth curves away as fast as the astronaut free-falls towards it. In free-fall, the astronaut doesn't feel gravity sucking them down because they don't slam into the earth.

anon141922
Post 54

Do you think wayne discovered the true story behind gravity or was it someone else?

anon138887
Post 53

Anti gravity device? Helium balloon. There is no gravity, there is only pressure. Can anyone prove this wrong?

anon133769
Post 52

Imagine stepping on the bathroom scale in space while in free-fall to earth. The reading will be very low as it will just represent the force of attraction between you and the scale. Same is true when done at the surface of the moon as both the moon and you are falling freely towards earth.

But what if the moon is attached to earth (like two bubbles joined together), what will be your weight when you step on top of the moon which is on top of the earth?

anon132233
Post 51

Is gravity the reaction caused by the push and pull force? Is the push and pull force on earth in equal measure, therefore producing gravity. In space, the push and pull force are not equal, causing free fall?

anon131687
Post 50

I don't know squat about squidoosh but how about this? Each body with mass exudes gravity waves, long gravity waves. If I'm floating in space far away from everything these waves are sent but there is nothing for them to attach to so I float.

Once I come close to an object, the two waves (from me and the object) meet and then the waves shorten (for some reason, the tricky part) and get higher in frequency, causing us to get closer. The more waves that hit me and mix with my outgoing waves, the stronger the combined contraction and the faster the attraction.

Once one can figure out how to break that contraction between objects, we'll have anti-grav. --Timo M

anon129350
Post 49

Gravity does have a negative effect on us humans since we stand erect compared to animals. By standing erect, gravity pulls against our internal organs and stomach and back muscles.

What I have learned is to counteract gravity it is healthy to wear a firm girdle to hold you in and counteract the negatives effects of gravity against your body.

anon121060
Post 48

You would think gravity would have to be a pushing force. If it were a pulling force, a black hole's gravitational pull would be too strong for gravity itself to escape to pull objects in? Just a theory I'm sure could easily be busted.

anon117385
Post 47

My theory is that at the center of every mass there is a black hole that has finally gotten enough material to plug the hole.

anon102958
Post 45

astronauts appear to be outside of earth's gravity due to previous explanation of momentum; they are 'falling' around the curve of the earth at the same speed as the spaceship which took them there;(usually17-25000mph). If they were placed in orbit at walking pace they would fall back to the earth. I think that's how it works, anyway. example(skylab)(armchair physicist).

anon86728
Post 43

Lots of interesting theories, but no true answers. A lot like life, lots of questions, few answers.

I only wish I had the intelligence to understand some of the theories.

anon79600
Post 42

We live in a 3-dimensional universe. The key to understanding gravity and much more is to think 3-dimensionally. In reality, the universe is much simpler than life itself, of any kind, and yet man is well on the way to deciphering that. Look to how the science of physics evolved, in order to understand what may have been misinterpreted.

anon79243
Post 41

anon78560: All matter in this universe, whether dark or atomized, exhibits gravity, from the tiniest particles to the largest massives. While the effect of gravity may be overcome by momentum, gravity itself can never be eliminated.

With respect to your 'bent space time' analogy, gravity is not the sole determinant of orbital position. I've given enough clues in the discussions of gravity, big bang, black holes, and E-M energy for you to figure out your own answers.

Gravity, like e-m energy, is generally described based on your viewing perspective. However, if you were an outside viewer, objects are actually pushed together. No more clues.

anon78560
Post 40

This is something my high school physics teacher could never tell me. I posed the hypothetical "if i tie a rope to you and pull, it's the rope pulling and moving you. But what is pulling when it comes to gravity?"

Gravity is more of an effect rather than a force. Massive objects bend space/time and create dips (think about pushing one finger down on a stretched piece of fabric, where your finger represents the sun and the fabric is spacetime (ha! funny isn't it?). Other less-massive objects get caught in the dips and start orbiting, like water in a toilet bowl or a sink.

Gravity is just the bending of spacetime by massive objects.

anon77861
Post 39

could gravity be just the interaction between all the atoms of everything in between. that is very possible as could be supported by string theory and interaction of all matter.

anon75020
Post 38

The complexity of your typical atom versus the primary particle is comparable to the space shuttle versus a paper airplane. The primary particle is one of the two items which make up the universe. What are its properties?

anon74824
Post 37

Three things:

1) There are only two things in this universe. All else is derived from them. What are they? and more importantly, what are their properties?

2) Matter is a like a condensate of space. Why?

3) Electrons don't collapse into the nucleus, and/or positive and negative charges a myth. Why?

anon74503
Post 36

has anyone ever thought it might be the spinning not the mass?

anon74440
Post 35

anon70993. Do not confuse momentum and gravity. If the sphere you speak of is planet earth (top heavy because of continental placement) then, yes, there is still a measure of gravity over its entire surface. Perhaps this is not what you meant.

Let's speed up earth's rotation until things begin to fly off. The planet still exerts a gravitational pull in all directions even while the momentum of objects near its equator match or exceed gravity's pull.

"Momentum does not negate gravity, it only negates the effect of gravity."

anon70993
Post 34

What if you have any size sphere which is heavier on its top half than on it's bottom half (let's say by 25 percent) and is spinning in one direction. The northern most point of the (top heavy) sphere is pointing straight up as well. Think there would be a measure of gravity on its entire surface?

anon67585
Post 33

I don't know. Gravity is something that pulls your force toward whatever and it depends on where you are.

anon61379
Post 32

No, not a "pulling force" Not even a "force"!

Gravity is the result of other forces at work.

Bodies (O) in space disturb the external forces** (+) creating an area of lesser forces (-) between them.

Resulting in: +O-O+

The (+) forces will then "push" the two bodies closer together.

The same reasons floating objects on water come together.

** There are many causes of these forces, radiation, magnetics, light, and no doubt many of which we are not yet aware or able to detect.

Namaste ~ Thor

anon58324
Post 31

i am not completely sure but here goes: the theory of space as we know it has no or very few molecules, so the influence of gravity from the earth is very little unless a large enough object comes in contact with our own molecule field which then is pulled inward by weak gravity fields.

Then, as it travels downward, it is then pushed by the weight of molecules on top of them. The turning of an iron and metal core creates magnetism in the center of the earth, thus north /south poles. albert e

anon58314
Post 29

you are so very wrong if you think a spinning object creates no gravity. many circus rides have proved otherwise. they spin you so fast that the inertia of its independent gravity even while being upside down without restraints. It will not let you fall until motion is slowed.

anon58313
Post 28

doesn't barometric pressure come into play when we go toward the center of the earth if so is this not related to gravity i have always supposed that the closer to the core the more gravity /exception at point 0 of center of core where some molecules might be more stationery? it seems to me any object tuning in a circular motion at a high enough rate of speed produces gravity.

anon56581
Post 27

To the "If anyone is interested" person: You seem very intelligent and knowledgeable, but please quit the repugnant self-righteous stuff.

If people reading this were not interested, they would not be here, and have some respect for physicists who keep a skeptical, scientific outlook on the subject. Remember, a wise man is one who confesses to not knowing all the answers.

anon56415
Post 26

For anyone interested: Gravity is weak because of the electron.

anon56163
Post 25

Gravity has to be part of the characteristics of space. When an astronaut is floating in space that person is not outside the effects of gravity.

Gravity is not a pulling force -- it only appears that way. That astronaut is in orbit at 17,000 mph, falling around the earth equal to the speed of the objects around him. Space's expression of gravity with respect to Earth extends for a million miles or more. At that point an object is part of an expression of gravity to the Sun's battle with space.

anon53254
Post 24

For anyone interested: Yes, gravity can be described, measured and calculated -- and that is what it is.

What you do not understand is, "what causes it". There are people who understand gravity and how it can both attract and repel. All that I am willing to tell you is that "it is a property of the medium".

anon52957
Post 23

The short answer to "What is Gravity ?"

Nobody knows !

We do know how to measure it and calculate its affects but we do not know what it actually IS.

Rates up there with "What is an Electron?" Is it a discrete material particle or a quantum wave structure?

anon52941
Post 22

For anyone interested: Simply stated, gravity is a property of the medium.

Gravity attracts and repels very similar to magnetic forces. Ask yourself this question: why is gravity the weakest of all the known forces yet when it comes to black holes, it becomes the strongest of the forces? Understand this paradox and you will understand gravity. It is not complicated. An open mind works much better than a closed one.

anon47705
Post 21

For anyone interested: Gravity is very much like the buoyant ball in water. The ball floats to the surface. But why does it stop there? If the ball were lighter than air, it would continue to rise. For anyone who knows anything about the true nature of gravity, this is a good analogy. It describes why electrons do not fall into the nucleus -- and, yes, normal space is very much a real quantity. Light and all e-m radiation are simply pressure waves in normal space. Black holes are simply the absence of normal space. Physicists need to rethink the positive and negative forces. They are the two sides of one force. It is human nature that holds physicists back from the unified theory. If a lay person can figure it out, why can't they? The answer is all around them yet they do not see!

anon45103
Post 20

For anyone interested: Tesla was right. We live in a fluid universe and as soon as our physicists realize this, the sooner they'll be able to "discover" the unified theory. Magnetic and electric fields are positive proof of its existence -- never mind light and gravity. Welcome to the "fishbowl" folks. A special "Hi" to all you 'armchair' physicists. What a pleasure. :)

anon44606
Post 19

Read the summation of Tesla's Dynamic Theory of Gravity. Most of his work was confiscated.

Gravity is the result of zero point energy in

space (either) beating down on matter, creating a push on planet earth. That's why gravity decreases as you go deeper (gets screened off).

anon44493
Post 18

What is the reason for gravitational force? or why do bodies with mass attract each other?

anon44114
Post 17

For anyone interested. Gravity is both a push and a pull -- it's only a matter of scale. Push means repel and pull means attract. At the subatomic level it attracts and repels. Anyone who really understands the mechanics of gravity knows this. It explains many things in the cosmos, but it also means that there are many more processes as yet undiscovered. all to do with the assembly of dark matter. All that we see is the atomized version of matter. you could say we are 'light' matter.

anon43273
Post 16

Gravity is not a pulling force, it is a pushing force. Consider it like holding a soccer ball underwater, it is the force acting on the outside of the ball. On an astronical context it is the displacement of a bodies mass of space-time.

The only weight we would have in space is not from gravity but from inertia. If you were stranded 200KM above earth and stationary you would weigh nothing. The force decreases according to the inverse square rule, so you wouldn't have to go far out to become weightless.

An interesting point is that if it is a pulling force, where is the centre of the force? If it was pulling with the same force in every direction the true center of gravity would be at the earths core, and the engery would be coming from somewhere and getting converted to something else (law of conservation). However modern measurments have proved that as soon as we go underground we become lighter. That rules out any pulling force.

Einstein was correct, gravity is the distortion or warping of space-time, and it is the bodies' mass that determines the magnitude of this distortion. It is an effect rather than a force, which means that as far as I am concerned we will never bo able to isolate a particle which could be described as a Graviton.

Some sort of solution might transpire if CERN manage to prove the existence of the Higgs?

anon43013
Post 15

WiseGeek does not explain what gravity is!

It only reflects on how we make use of it.

Is it a 'pull or a push'? From the Tamarack

Mines Mystery, it would appear to be a push

towards the centre of the earth.

It does have similarity to magnetism.

anon41444
Post 14

Isn't Newton's first law is to do with inertia? "An object at rest remains at rest and an object in motion remains in motion, with constant speed and direction, unless acted upon by an external unbalanced force."

The 'first law' stated in the article is actually Newton's Law of Universal Gravitation.

Robert J. Schofield [physics teacher]

anon40227
Post 13

Roy Masters says he knows what gravity is, namely a Spin Force. Does anyone wish to comment on what he says?

anon35712
Post 12

Objects with mass bend and warp space-time

around themselves causing the effect of gravity... Just another illusion interpreted holographically, by our brains, in this ever so unreal, reality, we so blindly overlook, in our cultures way to subdue closed minds. Think people, maybe do some DMT, that is if you're looking for a real answer. Gravity is just one of physics, blundering questions, seeing that it takes observation by consciousness for anything to exist in the first place... Here's a problem. The measurement problem in quantum mechanics is the unresolved problem of how (or if) wavefunction collapse occurs during conscious observation... Look that up, stop dealing with the petty ideas we can't probe yet, at least not to those depths of gravity, with the LHC is impossible... Have fun people... DMT... Just do it!

anon35312
Post 11

I can't find anyone who can explain what gravity actually is..!!

They say it is a force of attraction between objects,, but why would a object with mass attract another object with mass..

It is not a magnetic attraction, or magnetic objects would be attracted more than non magnetic objects..

Everyone can explain how it works,, but not why it works..!!!

Must all just be a dream if the why cannot be answered..

anon29058
Post 10

Is the value of gravity the same throughout earth? Explain.

anon26954
Post 9

Let me pose a question, No one can explain gravity. My thoughts about gravity are this. Everyone thinks the earth spins and that is what is pulling us to earth. However, spin something at a high rate and what happens? It goes away from you. So my theory is this. Space is pushing us and all things to earth. The earth's atmosphere keeps us alive, acts like a shield but it allows the force of the universe through and pushes us into the earth. Questions, concerns?

anon23233
Post 8

the reason is that universal gravitation is a really small force, 6.67*10^-11, so in order for two bodies to attract each other, they have to be of a really large mass to compensate for the small attraction force. at least that's what i just learnt in physics class. hope it helps!

anon22913
Post 7

are stars considered to be free-falling? and if not, what is holding them up? sorry to ask a question and have no answers.

anon11626
Post 3

I have discovered when we speak of free fall we seem to be talking about falling in a state with the force of gravity and against it. Even though the detection of g-waves has not been achieved and it seems likely will not be - hence. for Einstein's assertion that this is the restraints to why things fall in the manner they do. But I have also found that the percentage of free fall due to weight - it is not gravity that is constant but it is weight.

Pertinent of g-waves I don\'t think they exist either. The interaction of free fall determined by an objects weight - does not exist to the physical application of waves because if it were so - placing a plate between the object and the secondary mass would illustrate the means in difference. The fact that no one can weigh something as it moves - well, gravity free fall is the act of falling through empty space and not pulled down by a g-wave but is falling with the pressure of space. In outer space a person floats because gravity doesn't exist at a distance like close to a distance on earth. A body floats because gravity which creates weight - in space is exempt as a field. Its zero point energy. Again in space one floats with pressure that same effect where on earth one falls

anon5820
Post 2

Imagine you are in an elevator at the top of a tall building, and its cable breaks. During the elevator's fall to the ground you will experience weightlessness because you are falling freely in response to the Earth's gravity field. Consider now a parachutist who jumps from a plane moving 100 miles per hour. He also experiences weightlessness until the chute opens, even though he is well inside the Earth's gravity field, and may be moving forward at 100 mph while in free fall in response to the Earth's gravity. During the time he fell towards the surface he moved far enough forward that the curvature of the Earth made him fall a couple feet further than the height he was at when he jumped.

In the same manner, an astronaut is in free fall under the Earth's gravity but is also moving so fast forward that during the time he's fallen a foot, he's moved far enough forward that the curvature of the Earth has dropped a foot below him. For every foot he moves toward the earth's surface he's also moved far enough forward that the surface is another foot farther away. Thus, he continues falling toward the surface forever, while the surface curves away from him. He feels weightlessness continuously, without a stop at the bottom that abruptly terminates the experience for the elevator rider or the parachutist.

The astronaut's experience of weightlessness is a result of being in a state of free fall, which one can experience, at least for short times, very near the surface. The force of gravity at the altitude astronauts orbit is hardly reduced at all, relative to that on the surface. If one were to build a platform 300 miles high (approximately the altitude of satellites in near Earth orbit), stand there and weigh one's self, they'd find their weight only about 3% less than it was at sea level.

Steven K. Smith

Moderator's reply: Thanks for that interesting post!

anon451
Post 1

Astronauts' experience of weighlessness has nothing to do with being "outside the field of gravitational force" as stated in the article. The experience of weightlessness is due to being in a state of free fall while in orbit around the earth, or while coasting between bodies, the earth and moon for example. The moon is definitely within the earth's gravitational field, for example, at 384,000 km distant, so an astronaut orbiting a few hundred km high would certainly be in earth's gravitational field as well.

Steven K. Smith

[email removed]

Moderator's reply: Though I'm not sure, I think the reason why astronauts appear to be outside of earth's gravitational pull is because they have such little mass (relative to the moon, for example). So they are out of the earth's pull, based on their size, but not out of the range of earth's pull for larger objects.

Can anyone else shed some light on this?

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