How gravity works

[Tatetopa]

Hi Trevor.  When one writes a story,  one tries to entice the reader to follow from beginning to end.  Useful tools for a writer might be style, suspense, timing, and a plot the reader can follow.   When one writes poetry, one sometimes tries to evoke an image, maybe a single thought or moment in time.  If your aim is one of these, my most useful criticism is to clean up the style, reduce redundancy and stick to your plot.  Distill your thoughts into a few sentences in a paragraph or two.

When physicists tell each other stories, they use words and also mathematics.  Good stories about physics can be surprising, but like a good detective story, a good physics story reveals the clues and leads the reader to the inevitable conclusion.  The clues are mathematical. Even if the reader had not thought of them before, when revealed, they make inescapable sense in a familiar language.  As with any good story, a good physics story has a moral or homily.  You gain an insight that you can take away and apply to the larger world.

The best criticism I can offer for your story is that it leads nowhere.  It offers nothing the reader can take away to increase their understanding of the world.  it leaves the reader unsatisfied and tempted to say, "So what?"   It becomes an artifact of self-interest, seemingly not concerned with whether the reader comes along or not. It is like one of those conversations  that starts off with, "I had the strangest dream the other night."

 

[trevor borocz johnson]

here's a one minute video that further explains my earlier thread on how gravity works:

 

[Lilly]

Here's what I choose to use to explain gravity:

[StarMountainKid]

Whatever happened to sepulchrave?

[StarMountainKid]

Because quarks have mass, I suppose you could say quarks are partly responsible for gravity. Thing is, we don't yet have a quantum theory of gravity.

[Hawken]

[Rlyeh]

4 hours ago, StarMountainKid said:

Because quarks have mass, I suppose you could say quarks are partly responsible for gravity. Thing is, we don't yet have a quantum theory of gravity.

What about electrons?

[StarMountainKid]

5 minutes ago, Rlyeh said:

What about electrons?

Yes, all those particles have mass except the photon. I just didn't mention them.

[Leonardo]

On 23/06/2016 at 1:52 AM, trevorjobo said:

Theoretical Physics
By Trevor Borocz Johnson

 

A universe and a quark are composed of the same substance that is Space-time...

There is no "aether". Spacetime is not a "substance", but properties of the universe's physical manifestation. Those properties are smooth in the absence of mass and/or energy, but become "bumpy" when interfered with by mass and/or energy. This "bumpiness" is gravity. The force of gravity is in the direction of the slope of the "bump" towards the centre of mass/energy.

A universe or quark is then composed of cubic void blocks and energy lining those void blocks in a cubic honeycomb symmetry. A universe or quark is shaped like a cube.

A cuboid is not a possible description of the way force propagates equally in all directions from a source. Neither the universe, nor quarks, could possibly be "cube-shaped".

[Bendy Demon]

I will admit that I really do not understand the theories of how gravity works nor how it is even generated however I was doing some contemplation recently and began to wonder how it is possible for several bodies such as our planets to stay in their relative places while orbiting a star that is also moving.

I ask this because I was told that gravity waves act on one another both attracting and repelling at the same time. However I was also told that, generally speaking, larger bodies have greater gravitational pull so why doesn't the sun override all the other gravitational fields and just suck everything in towards itself?

Since the sun is not stationary, is its own movement enough to keep it from absorbing all other planets yet still keeping them "tethered"?

And yes, I know I am "ignorant" on such matters so don't chastise me too harshly, ok?

[StarMountainKid]

I was wondering once, if you place an object in a gravity well (say the gravitational attraction of a planet), why would it not remain stationary? Since gravity is not a force, gravity is a warping of space-time, and therefore there is no force attracting it, what would cause a stationary object to move towards the gravitational body?

Sepulchrave, our one-time physicist member said in essence, it just does. (?)  In the old stretched sheet demonstration, where a bowling ball is in the center of the sheet and a marble is placed is on the edge of the sheet, the marble rolls towards the bowling ball, demonstrating the warping of space-time  But the marble rolls toward the bowling ball because of the gravity of the Earth under the sheet. In space it would seem to me the marble would remain stationary, as no force is acting on it.

[Merc14]

1 hour ago, Ryu said:

I will admit that I really do not understand the theories of how gravity works nor how it is even generated however I was doing some contemplation recently and began to wonder how it is possible for several bodies such as our planets to stay in their relative places while orbiting a star that is also moving.

I ask this because I was told that gravity waves act on one another both attracting and repelling at the same time. However I was also told that, generally speaking, larger bodies have greater gravitational pull so why doesn't the sun override all the other gravitational fields and just suck everything in towards itself?

Since the sun is not stationary, is its own movement enough to keep it from absorbing all other planets yet still keeping them "tethered"?

And yes, I know I am "ignorant" on such matters so don't chastise me too harshly, ok?

This teacher does a very good job of explaining Einstein's theory of how gravity works 

 

[StarMountainKid]

The above video explaining gravity by spandex is all well and good, but the reason the objects roll toward each other is because of the gravity of the Earth below the spandex. In three-dimensional space, since gravity propagates at the speed of light, in the Earth-Moon system for instance, the position of the Earth is constantly being displaced relative to the Moon, so that at every instant the the position of the Earth's gravitational well must propagate to the Moon at the speed of light.

In this sense, it seems to me the orbit of the Moon around the Earth would always lag behind in its orbital position. Just a question I have about gravity..

[Merc14]

57 minutes ago, StarMountainKid said:

The above video explaining gravity by spandex is all well and good, but the reason the objects roll toward each other is because of the gravity of the Earth below the spandex. In three-dimensional space, since gravity propagates at the speed of light, in the Earth-Moon system for instance, the position of the Earth is constantly being displaced relative to the Moon, so that at every instant the the position of the Earth's gravitational well must propagate to the Moon at the speed of light.

In this sense, it seems to me the orbit of the Moon around the Earth would always lag behind in its orbital position. Just a question I have about gravity..

Actually it is not, it is because of the friction from the fabric, #1, friction from the air, a long way away #2, and earth's gravity, a long, long way to last reaon. SBS.  This is a simple illustration of how Einstein explained the bending of space and time, nothing more, but if you are a moron and don't understand that then you post stupid things.  Not saying you posted a moronic response, of course, but I have a question.  The High School kids understood this was a very simple illustration and the teacher even explained it as such, and also explained why it isn't realistic, but you seemingly missed all that and still mistook what you were watching.  Do you feel kind of stupid that a High School lesson is above your comprehension? 

Edited July 17, 2016 by Merc14

[trevor borocz johnson]

1 hour ago, StarMountainKid said:

since gravity propagates at the speed of light,

Light is a heavy squeezing on space-time. It's far slower then gravity waves which only have space-time to slow them down. I'm thinking a gravity wave could travel the entire length of the galaxy, 80,000 light years? in a matter of seconds. Gravity waves from objects in the Milky Way, within its central black hole's gravity field, would be detectable with super powerful, and sensitive equipment to which we may tune into a modern alien radio.

Edited July 17, 2016 by trevorjobo

[StarMountainKid]

57 minutes ago, Merc14 said:

Actually it is not, it is because of the friction from the fabric, #1, friction from the air, a long way away #2, and earth's gravity, a long, long way to last reaon. SBS.  This is a simple illustration of how Einstein explained the bending of space and time, nothing more, but if you are a moron and don't understand that then you post stupid things.  Not saying you posted a moronic response, of course, but I have a question.  The High School kids understood this was a very simple illustration and the teacher even explained it as such, and also explained why it isn't realistic, but you seemingly missed all that and still mistook what you were watching.  Do you feel kind of stupid that a High School lesson is above your comprehension? 

lol Yes, I understand the analogy of the spandex illustration and the curvature of space-time. It's a good way to demonstrate gravity. Of course, the reason the illustration works is because the gravity of the Earth is pulling down on the weight of the object on the spandex. The point of my post was not that I didn't understand the illustration, sorry if I gave that impression (from my post I'm not sure how you came to the conclusion that I didn't understand the illustration). The point I was trying to make was that since gravity propagates at the speed of light and not instantaneously, would there not be a propagation delay between the gravitational attraction of two orbiting bodies?

  .

[Leonardo]

1 hour ago, StarMountainKid said:

lol Yes, I understand the analogy of the spandex illustration and the curvature of space-time. It's a good way to demonstrate gravity. Of course, the reason the illustration works is because the gravity of the Earth is pulling down on the weight of the object on the spandex. The point of my post was not that I didn't understand the illustration, sorry if I gave that impression (from my post I'm not sure how you came to the conclusion that I didn't understand the illustration). The point I was trying to make was that since gravity propagates at the speed of light and not instantaneously, would there not be a propagation delay between the gravitational attraction of two orbiting bodies?

  .

Masses within each other's gravitational reach can only "not fall towards each other" if the relative motion between them attains or exceeds a level of kinetic energy necessary to overcome the "slope" of spacetime caused by the interaction of each mass with it. Some objects in Earth's gravity well are stationary (well, relatively so) in relation to Earth because we have put them into orbits with sufficient kinetic energy to remain so.

And yes, there is a propagation delay. If the Sun were to suddenly disappear it would take approx 8 minutes for the local spacetime around the now missing Sun to "unwrinkle itself" to the extent that Earth then became unaffected by the Sun's gravity and flies off out of the solar system.

[sepulchrave]

18 hours ago, StarMountainKid said:

Whatever happened to sepulchrave?

I'm still here... I just didn't see any merit in posting: Until now, there was nothing for me to respond to. ChrLzs did a good job summarizing the lack of merit in trevorjobo's original post, and trevorjobo did a good job ignoring everyone and everything that did not support his/her viewpoint.

I agree with yours, Lilly's, and Leonardo's posts, but I seriously doubt there is any merit in attempting to engage trevojobo in debate - let alone try to convince him/her that the cumulative efforts of 300 years of intense research by hundreds of exceptionally intelligent people, a few thousand years of carefully recorded astronomical observations, and billions of dollars in research money may have lead to a more accurate description of the Universe in general and gravity in particular than his/her random musings.

*************

With regard to your question about the rubber sheet analogy: Yes, in reality it only works because of the ever-present and roughly uniform gravity of Earth. That is why the rubber sheet analogy is an analogy. The curvature of the rubber sheet provides a means of visualizing the magnitude of the force.

Obviously the rubber sheet is only 2-dimensional, while space is 3-dimensional, so it fails to capture the whole picture. What is also very important, but slightly more subtle, is that the value of the rubber sheet analogy comes from it applying to space-time (3+1-dimensional). If you could view space-time as a surface (i.e. if you were a 5-dimensional being somehow able to view the 3+1 space-time of our Universe), you would see that the motion of planets, comets, stars, etc. simply follow the shortest paths between two points. From our actual perspective, as beings embedded in the 3+1 space-time, the trajectories of planets, comets, stars, etc. seems a lot more complicated (ellipses, hyperbolas, etc.).

The fact that gravitational force has an effect on time (unlike, say, electrostatic force) is the reason why we try to employ analogies like the rubber sheet to gravity but we never use these analogies for other forces.

11 hours ago, Ryu said:

I will admit that I really do not understand the theories of how gravity works nor how it is even generated however I was doing some contemplation recently and began to wonder how it is possible for several bodies such as our planets to stay in their relative places while orbiting a star that is also moving.

I ask this because I was told that gravity waves act on one another both attracting and repelling at the same time. However I was also told that, generally speaking, larger bodies have greater gravitational pull so why doesn't the sun override all the other gravitational fields and just suck everything in towards itself?

Since the sun is not stationary, is its own movement enough to keep it from absorbing all other planets yet still keeping them "tethered"?

And yes, I know I am "ignorant" on such matters so don't chastise me too harshly, ok?

The Sun does "suck everything in towards itself", but it is not the Sun's relative motion that is necessary but the planets' relative motion. Each planet has a substantial momentum perpendicular to the Sun, and this momentum is sufficient such that the Sun's gravity is only able to continuously curve the trajectory of the planet, but not curve it enough for the planet to fall into the Sun.

Actually there are 2 caveats worth mentioning:

1. There are forces of friction affecting the planets, like the gravity from the rest of the galaxy, and other galaxies, and the Solar wind, and the Solar and galactic magnetic fields, so the planets will eventually spiral into the Sun (or may eventually wander away from the Sun).
2. The motion of the Sun and all the planets is chaotic (if more than 2 objects are interacting gravitationally the result is always chaotic), so even if there were no friction it is basically inevitable that the planets will either collide with the Sun or go spinning off into space.

[Thorvir]

On 6/27/2016 at 6:29 PM, trevorjobo said:

when you die you enter into the next dimension of the infinitely divisible, the quark dimension where you become yourself with your previous lives circumstances and are a person's size inside a quark the same ratio as your size to the present universe. to say that quarks are point particles is like saying "for all we know, we can't divide smaller then a quark" which is rubbish.

And your proof for such is....?

[trevor borocz johnson]

On 7/16/2016 at 10:24 PM, Merc14 said:

This teacher does a very good job of explaining Einstein's theory of how gravity works

 

On 7/16/2016 at 1:29 PM, trevorjobo said:

 

here's a one minute video that further explains my earlier thread on how gravity works:

 

 

don't let this limit your thinking

[ChrLzs]

And.. don't open your mind so much that your brains fall out...

Handwaving words like "light is a heavy squeezing on space time" is just meaningless word salad.  You need to talk about observations that prove you correct (or better than current theories) and mathematical descriptions that show your ramblings actually match what we observe.

Not once have you done that.

[Emma_Acid]

I believe the phrase is "so wrong it's not even wrong"

[trevor borocz johnson]

On July 24, 2016 at 10:59 AM, Emma_Acid said:

I believe the phrase is "so wrong it's not even wrong"

oh yeah that old saying. Anyways to almost everyone who has responded, how dumb do you think I am? Do you think I don't already know there is no definitive explanation for gravity and that current thinking is that it leaks into our universe from particles or is caused by gravitino's? Almost all of you people need to respond with respect to what you have reoccurringly claimed as your side opposing mine (cough cough) and that is current established physics to which if you look the current understanding of the mechanism by which gravity's attraction occurs is CURRENTLY UNEXPLAINED, not bending or warping, not the ball on the cloth, not newton Einstein Pascal Da Vinci who else?

Edited July 29, 2016 by trevorjobo

[aquatus1]

On 7/16/2016 at 6:19 PM, Hawkin said:

Nonsense.

Gravity pulls.

[trevor borocz johnson]

On July 23, 2016 at 1:16 AM, ChrLzs said:

You need to talk about observations that prove you correct

Sure, we can readily observe that gravity fields need no medium other then space-time to act on each other. If Einstein is correct that gravity warps space-time in a 2 dimensional way, then we can say that 3 dimensionally this would look like a squeezing on the grid of space-time. If the denser space-time of two gravity fields acts on each other, then we can observe that the particles that cause gravity, quarks, are particles of hyper dense space-time that transcend a squeezing force outward that dilutes itself into the vastness.