What is gravity....exactly?

OK here is the best way to describe gravity for everyone to understand. Gravity is simply the effect an object of mass has upon space time. Now this is quite hard to imagine, I know. So I will give you a rather simple example of how it all works.

Imagine a bucket. Over the rim of the bucket is some cling film/foil, stretched out tight so that it sort of forms a lid on the bucket. Now this film covering the opening in the bucket, this is a metaphor for space time. (Space time, in a very simple definitions, is the world around you as it progresses through time). Now if we take an object of mass, lets say a pound coin, and place it on the film (spacetime), it will create a little indent, as its weight presses down on the tight film. This is the effect that an object of mass has on space time (albeit simplified). The object has distorted space time. Now next to your pound coin, you should place a smaller lighter object. Lets say a pea. Now this pea when placed near enough to the pound coin, will role towards the coin. This is gravity. The attraction is caused by the larger objects impression in space time.

So that is a basic explanation of gravity (for all the scientists here, yes I know it is more complicated, but at least people understand it this way, please dont flame).

Now here is something that could be of interest to you. If you bare in mind my explanation above of space time and gravity, I will expand on this to discuss how time travel could THEORETICALLY be possible, using extreme gravity (its actually impossible, with our technology and relies on some presumptions being correct, but interesting nonetheless).

Now going back to the bucket example. Time is obviously not a disk, it does not suddenly end. There are many people in science who describe space time as being a sphere, with the current point in time (the present) progressing around the outer rim of the sphere. Kind of like putting your finger on a ball and then turning the ball with your other hand, the point that your finger touches is the present, that which is behind your finger is the past and the part of the ball in front of your finger that is approching is the future. Now instead of the bucket explanation, I will now use the sphere as an example of space time. Lets make it easy, space time is a balloon. If you place an object of mass onto the balloon (space time) it will make an indent like the film on the bucket. Now if this object is heavy enough, the object will cause such an indent that the object will touch the inside surface of the other side of the balloon. (Imagine pushing your finger hard into a balloon, without popping it and touching the other side). Now the point where your finger entered the balloon, that is the present. The end of your finger is touching the other side of the balloon, which would be either the future or the past (in all honesty, nobody knows, they only know that it cant be the present). That which I just described to you, is basically a worm hole, and theoretically could enable time travel.

Anyway, hope you can understand it a bit better now.

All the best Pryde

Originally posted by K J Gunderson

Originally posted by sirnex
reply to post by Deaf Alien

 

Time doesn't exist my friend. Never had and never will. We've never once measured time nor can we even point at a source of time. The closest thing we can use to describe time is entropy, and that is far removed from any silly concept of 'space-time'. What the universe is composed of is a void filled with matter. What that void is and what matter is is still unknown, especially why it all exists.

Certainly is not akin to a ginormous rubber sheet.

What am I measuring when I calculate the difference between now and later?

First show me a measurable distance between now and later or then and now. We don't exist in the later, now and we don't exist in the then, now. We exist in the now at a constant rate determined by entropy. Do you disagree with entropy?

I have read and watched segments on TV on gravity, on one show on The History Channel, a scientist did a demonstration where he used two different heavy glass balls and placed them on a sheet of rubber suspended in a ring, like a trampoline. Then he showed the displacement of the sheet of rubber by the different weighted balls, the heavier one depressed the rubber down more than the smaller, lighter ball. He then rolled a coin (representing the earth) in around the dip in the rubber (representing fabric of space) which then rolled in a circular orbit around the large glass ball (representing the sun) and it rolled round and round the ball, but of course it got closer and closer until the coin collided with the glass ball.
The same demo with the smaller glass ball showed a lower pull on the coin. That didn't do it for me, I just cannot seem to get my hand around the "fabric of space-time" theory. If the planets sit on this fabric, and push down on it, that to me is not gravity, why would the fabric of space have only one plane to it, unless it is an invisible field or sheet of resistance sitting in the middle of space (it has a top side with high downward pressure traits, and an underside with low pressure traits, or is it in layered levels.
I think gravity has more to do with the solar aspects of the suns in the universe, I also suspect that planets (ours too) all have a central core sun (molten core) and are hollow with more terrain inside, an inverted earth makes sense that Our Creator wasted nothing when designing life and worlds. I just cant seem to understand it

According to this experiment gravity propagates somewhere near the speed of light.

www.nrao.edu...

I wonder if they knew this back when they were calculating the path of the Pioneer spacecraft through the gravity wells of the planets? You would get slightly different gravitational accelerations if you assumed planetary gravity wells didn't have any leading or trailing asymmetry.

You have to ask yourself why does gravity have to propagate?

reply to post by tauristercus


I honestly couldn't answer this question, but that would be one hell of a show to witness.

I am guessing it would happen instantaneously, but the real question would be what would happen next...

Would we be flung in the direction we were headed in or would all the planets be drawn in by Jupiter since it's the heavy weight of our universe?

Any way great secondary question regarding the OP.

_______________________________________________________________

As for the OP, no one actually knows what Gravity is, it's just a name given to a theories on movements of different bodies. For all we know it's something completely different, heck magnetic force for all I know. I mean we do know something is causing bodies to react toward each other and we call it gravity, but that is the extent of our simple minds.

Originally posted by jymmyjaymes
I have read and watched segments on TV on gravity, on one show on The History Channel, a scientist did a demonstration where he used two different heavy glass balls and placed them on a sheet of rubber suspended in a ring, like a trampoline. Then he showed the displacement of the sheet of rubber by the different weighted balls, the heavier one depressed the rubber down more than the smaller, lighter ball. He then rolled a coin (representing the earth) in around the dip in the rubber (representing fabric of space) which then rolled in a circular orbit around the large glass ball (representing the sun) and it rolled round and round the ball, but of course it got closer and closer until the coin collided with the glass ball.
The same demo with the smaller glass ball showed a lower pull on the coin. That didn't do it for me, I just cannot seem to get my hand around the "fabric of space-time" theory. If the planets sit on this fabric, and push down on it, that to me is not gravity, why would the fabric of space have only one plane to it, unless it is an invisible field or sheet of resistance sitting in the middle of space (it has a top side with high downward pressure traits, and an underside with low pressure traits, or is it in layered levels.
I think gravity has more to do with the solar aspects of the suns in the universe, I also suspect that planets (ours too) all have a central core sun (molten core) and are hollow with more terrain inside, an inverted earth makes sense that Our Creator wasted nothing when designing life and worlds. I just cant seem to understand it

The rubber sheet analogy of gravity is just plain garbage. None of the other forces are said to work even remotely like that themselves, so why would gravity be any different than the other forces? So long as we hold onto this rubber sheet hogwash, we'll never understand gravity.

Would love to read through this thread but the OP's avatar background is too distracting for me to keep my eyes on the text.

Originally posted by sirnex

Originally posted by jymmyjaymes
If the planets sit on this fabric, and push down on it, that to me is not gravity, why would the fabric of space have only one plane to it

The rubber sheet analogy of gravity is just plain garbage.

I think you are both taking the rubber sheet analogy too literally. As cosmology professor Alex Filippenko likes to say, an analogy only works as far as it works, and at some point it fails to accurately represent the thing it is trying to represent. This is true for the rubber sheet analogy and virtually any other analogy you can think of, since all are imperfect representations of something else.

The fabric of space doesn't have just one plane to it, in other words, that's just a tool to help us conceptualize gravity, but it's definitely 3-dimensional.

If you throw out the analogy because you don't like it, that's fine, but Einstein's math has held up pretty well, though I suspect it's not perfect. If you've got better math, you'd be the new replacement for Einstein, but until that person comes along, Einstein's math works well regarding gravitational predictions.

Originally posted by an0maly33
Would love to read through this thread but the OP's avatar background is too distracting for me to keep my eyes on the text.

I agree it's annoying, but there's a simple solution, just hit the escape key to stop the animation.

Unfortunately that stops ALL animations on the page, including those that aren't annoying. But most animations ARE annoying, only the exceptions are not.

Issac Newton explains gravitational force about 200 years ago which has been proven consistently as applied to all bodies in outer space.

For example, how does one calculate the existence and mass of an invisible planet, in distant galaxies, too far away to be seen with telescopes, the Hubble telescope or otherwise ?

They actually look for and measure the wobble in the orbit of the central star and from that they calculate the size and mass of the planet to cause the change in orbit or wobble of the stars orbit based upon the weight of said planet.

How do they measure the wobble in orbit precisely ?
They use what is called the doppler effect, the same thing used in radar systems.
They actually bounce signals off of remote stars or planets and use the information to calculate the variances in orbital speed and direction of the signal from that which was sent.


Take a course in basic Physics and then in Astrophysics, it would explain quite a bit of what you are hypothesizing here.

I think one's layperson understanding of 'gravity' is the 'force' that draws masses 'together'.

Now if we think of space being warped stretched into a 4th dimension by mass & perhaps gravitons pushing/flowing unidirectionally along this additional dimension then the reason objects seem to be 'attracted' one another is more a matter of them following this geometric conformation of space-time rather than any intrinsic [in fact zero?] attraction between masses.

That would seem to fit with the notion that the 'attraction' force ie. 'gravity' [which arguably is non-existent] is so relatively weak. It is more an incidental appearance rather than intrinsic, driving effect.

The other thought of mine is that inherent in the notion of stretching/warping space-time is that there must be some kind of inherent tension that binds all of space-time together. The actual stuff of the integrity structure of space[-time]. It must have some calculable tensile strength that correlates with a maximum mass-load.
That suggests that warping of space might be possible in a non-'gravitational' vector. In otherwords with some kind of engineering you could use that warping potential in an 'up' &/or horizontal direction.

Also the means, manner, magnitude of that tensile strength is arguably the most fundamental element of the Universe [experience]. Its logic or mechanic operations. Understanding that might possibly open up whole new possibilities such as creating whole new Universes or proto-universes with identical or completely different physics from our own originating Universe.

It is after all the 'stuff that binds'.

[edit on 22-4-2010 by slank]

[atsimg]http://files.abovetopsecret.com/images/member/8865e2fda03f.jpg[/atsimg]

This is an interesting crop circle that may be the Alien blueprints for a gravity propulsion device. Note the quanta locks on the expander and the Iris on the gravitational lensing functions?

reply to post by sirnex

 

First show me a measurable distance between now and later or then and now. We don't exist in the later, now and we don't exist in the then, now. We exist in the now at a constant rate determined by entropy. Do you disagree with entropy?

This is what i refer to...people percieve time. Now, there are obviously philosophical discussions around what we are perceiving, but in the end the consensus reality will be that there is a "time", whether it is true or not.

Remember: science is based on observation as much as anything. Without observation there can be no proof. To tell someone that their observation as it relates to time is a fallacy creates a serious conflict of information.

And then people want to know why folks get disinterested in science. To the casual observer, such conflicts can make it appear more like witchcraft than science.


[edit on 22-4-2010 by bigfatfurrytexan]

Hello. I am new here. The reason I joined was because I was intrigued by this thread. I had a recent discussion with a physicist about this. I referred to Einstein's experiment of proving the existence of mass in the photon by photographing that light bends around the moon during a total eclipse. She countered that light has no mass but bends due to the gravity well caused by the moon. Now if you think about what she is saying, which is orthodox within the main stream physics community right now. She is saying that light has no mass yet reacts to a gravitational field as if it has mass. I cite Dr. Stephen Crothers work as attempting to solution this dilemma.

www.sjcrothers.plasmaresources.com...


Another thing I would like to comment on is that the sun itself is an electromagnetic orb. It does not in and of itself contain heat, what it radiates hits the earth as sunlight and the vibration within the molecular structure of all things creates what we perceive as heat. I cite Thunderbolts, The Electric Universe as source material.

www.holoscience.com/index.php

Thank you.

Awesome question!

I have a cursory understanding as gravity in general, but please be aware that Physicists still don't have a complete answer.

I have a friend that works at a partical accelerator searching for the Higgs-Bosson..the particle that is responsible for assigning mass...its a cousin of the elusive gravition

If we discover and figure out a way to master these particles....well imagine being able to direct a beam a few feet from an object (or ship) that tells the ship that it should fall in that direction...up down sideways etc.

In the rubber sheet example with a iron ball in the middle...and the sheet representing a space time continuam....imagine removing the heavy iron ball and pushing your finger into the fabric and then moving it in any direction...Imagine crafts making right hand turns at high speeds without centrifugal force consequences to the passengers.

It is the difference between propulsion and telling the natural forces that the object simply belongs somewhere else.

Physicists want to squeeze little old gravity into the standard model—the crown-jewel theory of modern physics that explains three other fundamental forces in physics—but none has succeeded. Like a runt at a pool party, gravity just doesn't fit in when using Einstein's theory of relativity, which explains gravity only on large scales

"Gravity is completely different from the other forces described by the standard model," said Mark Jackson, a theoretical physicist at Fermilab in Illinois. "When you do some calculations about small gravitational interactions, you get stupid answers. The math simply doesn't work."

Gremlins of gravity

The numbers may not jibe, but physicists have a hunch about gravity's unseen gremlins: Tiny, massless particles called gravitons that emanate gravitational fields.

www.livescience.com...

Originally posted by bigfatfurrytexan

reply to post by sirnex

 

First show me a measurable distance between now and later or then and now. We don't exist in the later, now and we don't exist in the then, now. We exist in the now at a constant rate determined by entropy. Do you disagree with entropy?

This is what i refer to...people percieve time. Now, there are obviously philosophical discussions around what we are perceiving, but in the end the consensus reality will be that there is a "time", whether it is true or not.

Remember: science is based on observation as much as anything. Without observation there can be no proof. To tell someone that their observation as it relates to time is a fallacy creates a serious conflict of information.

And then people want to know why folks get disinterested in science. To the casual observer, such conflicts can make it appear more like witchcraft than science.


[edit on 22-4-2010 by bigfatfurrytexan]

People don't perceive time though. What we do perceive is the rising and setting of the sun as our planet rotates and then we perceive seasonal changes as it orbits the sun. We then create a clock that measures these cycles in a series of sequential ticks that we call seconds, minutes, hours, days, months and years.

You don't count how many time's your heart beats and call it time do you? Why would we treat any other physical process differently? Time as an abstract concept of measure cycles and rate of sequential events is a useful tool, but not a good indicator of a physical constant. Science has never pointed to a universal rate of time. Science is now starting to understand that time doesn't exist in the way we've always thought it to exist and that it might possibly not exist at all.

The reason we haven't been visited by a time traveler is because no time traveler will ever have more energy than the entire universe or technology in which to reverse entropy for all matter within it.

This question bugs me to, the more you think on it the more it makes no sense. If gravity is a centrifugal force the earth goes around the sun, this cluster of planets goes around another cluster wich goes around another thill we have a spiral galaxy, then that galaxy is linked to another and so on. If the entire universe is matter reacting to matter then gravity will depend on the size/clumps of matter in this centrifugal process. Then gravity like time will be relative to what part of the universe your on, it could be an attraction the cosmos have on eachother but what does that mean, what does 'attraction' mean. But this still does not answer why some galaxys are moving away or why some objects that are smaller like black holes have more gravity, in the quantum world nothing stays constant to explain anything in how it relates to the larger picture. And what the hell is the bending of space supposed to be that large suns and planets are supposed to have an effect on, how can you bend something thats everywhere its like me bending the ocean when I swim, I displace it I dont bend it. And the electromagnetic effect we still dont know enough who knows maiby we live in a electrical universe, maiby the sun is electrical, but fusion works to so maiby its all these things having an effect on eachother that give the illusion of gravity, Maibe gravity is just how we discribe the curent state of the universe. And since time does not exist exempt in interactions by humans and measurements to keep track of the world and other humans. When we say space/time it could literally be like setting a route a destination and a time to get there like car pooling to work. Space/time is not part of the universe only part of the human conseption of the universe. But gravity effects all and the weird part is it does not effect all equally a magnet can pull against the centrifugal force of the earth and sun its like a ant moving a bus around. And the biggest weird part is the link between the big and small, space what the hell is space it ocupies 90% of the known universe everything we see is but 10% of all that is, if even that. What is the stuff in between planets and galaxys what is space made of. And then theres the Holographic Universe were gravity is an inverted inversion in itself that leads to itself. I could go on, but why bother, to answer your question, nope have no clue what gravity is the only thing I know is that it IS.

Originally posted by galadofwarthethird
Then gravity like time will be relative to what part of the universe your on, it could be an attraction the cosmos have on each other but what does that mean, what does 'attraction' mean. But this still does not answer why some galaxies are moving away or why some objects that are smaller like black holes have more gravity, in the quantum world nothing stays constant to explain anything in how it relates to the larger picture.

The reason that black holes have more gravity is because of their infinite energy density. According to Einstein energy and mass bend space time, so if the energy when it is being compacted it pulls space time into it creating a greater bend and warping space time more. But unfortunately the object is getting smaller as this happens.
Some galaxies are said to be moving away from each other by the expansion of the universe.

reply to post by Gentill Abdulla


Ya but thats just the thing unless you send a probe in to get info before its spagetified and assimilated by the black hole it's just theory. And when its being compacted and pulling space/time bending it, that says nothing something is happening   that we dont know in that place, and time that we observe it. So we call it space/time, like it getts to the nitty gritty of the heart of it, but all it is is a fancy way to say I dont know but I can assume bassed on technology that mesures light that something happens were the light cant escape to be measured. Who knows maiby the light is not sucked in maiby since they say light has no mass how can it be sucked in, maibe the actual black hole is smaller then the photon and has nothing to reflect off of, exept the mass that is attracted to the black hole that we see, the rest could just go by the black hole.How does something that supposedly has no mass/gravity attracted to something that has ridiculous amounts of gravity. And same for the galaxys that are moving away we dont know why they are moving away it could be they are attracted to something beyond our capability to see in the universe, so again it's just theory. And I dont even want to think abouth what infinite energy density means. I guess its another sequence of words that say super duper ultimate powerfully powerful thingy that we cant see.

Originally posted by galadofwarthethird
reply to post by Gentill Abdulla

 

Ya but thats just the thing unless you send a probe in to get info before its spagetified and assimilated by the black hole it's just theory. And when its being compacted and pulling space/time bending it, that says nothing something is happening   that we don't know in that place, and time that we observe it. So we call it space/time, like it gets to the bitty gritty of the heart of it, but all it is is a fancy way to say I don't know but I can assume based on technology that measures light that something happens were the light cant escape to be measured. Who knows maybe the light is not sucked in maybe since they say light has no mass how can it be sucked in, maybe the actual black hole is smaller then the photon and has nothing to reflect off of, except the mass that is attracted to the black hole that we see, the rest could just go by the black hole.How does something that supposedly has no mass/gravity attracted to something that has ridiculous amounts of gravity. And same for the galaxies that are moving away we don't know why they are moving away it could be they are attracted to something beyond our capability to see in the universe, so again it's just theory. And I don't even want to think about what infinite energy density means. I guess its another sequence of words that say super duper ultimate powerfully powerful thingy that we cant see.

Gravity bends light. This is because light is made up of photons. Photons are basically energy packets.