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jonmel77
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Force Behind Gravity
#23526917 - 08/10/16 02:17 AM (7 years, 5 months ago) |
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Gravity is equivalent to acceleration (so mathematically the same force). Acceleration requires a constant input of energy, via rocket booster, solar wind panel, gravitational attraction by a large body...
So the gravity sucking us down to the Earth needs a constant energy source. This energy must therefore be continuously suppled from the curvature of spacetime. So the space and time we see around us is slowly providing the energy which keeps us (and everything else) stuck to the Earth.
Spacetime is therefore slowly losing energy, on Earth and any other large gravitational body, to gravity. So time is progressively getting slower and space is be becoming more diffuse. Which over the course of billions of years appears similar to be an expanding universe - in the past time was progressing faster and space was more condensed.
Is there any theories taking into account the conservation of energy regarding the gravitational force? Does anyone ask where gravitational energy 'comes from', or is it assumed to just supply a constant force without consequence.
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nooneman


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Re: Force Behind Gravity [Re: jonmel77]
#23526932 - 08/10/16 02:27 AM (7 years, 5 months ago) |
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jonmel77
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Re: Force Behind Gravity [Re: nooneman]
#23526998 - 08/10/16 03:07 AM (7 years, 5 months ago) |
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So does this explain that scientists are looking towards spacetime as the source of energy behind gravity? And that the gravitons potentially responsible for such an interaction are too small to be currently observed, given that a detector would have to be the size of Jupiter?
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Jean-Luc Picard
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Re: Force Behind Gravity [Re: jonmel77]
#23527201 - 08/10/16 05:11 AM (7 years, 5 months ago) |
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You are looking at gravity strangly.
In order to move something against gravity (let's say pick up a ball and hold it above your head), you have to add energy to that object in the form of work (force x distance). Since energy is conserved, the energy that you added to the object must become something. Since you have no change in velocity between the initial and final states, and no real change in temperature or chemical composition, then it must be concluded that the work energy is bound up in potential energy, resultin from the difference in height relative to the center of a gravitational field.
This is further proven by releasing the ball. Without any outside influence (remember that in free-fall, you experience no external forces), the ball seems to magically gain kinetic energy. The amount of final energy gained (which can be easily calculated with classic ballistics formulas) will be exactly the energy needed previously to lift the ball up to the initial drop height. This has been tested over and over and over again with very reliable results.
If what you are saying is the case, and energy is still conserved, then a dropped ball would gain more kinetic energy than it takes to lift it up to the same height, and our physics equations would have been completely different from the beginning.
-------------------- The universe is under no obligation to make sense to you - NDT
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jonmel77
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Thanks for the reply agmotes.
Suppose you hold the ball straight out in front of you. There is no net gain or loss to its potential energy but it still wants to fall to the floor and requires force from your arms to hold it in position.
Gravity is constantly trying to pull the ball down. This is an alternative way to look at gravity than simple Newtonian mechanics. The electromagnetic forces of your body and the floor you are standing on are able to resist the motion of the ball towards the floor. But they require continuous effort. Even if you placed the ball on the floor then the electromagnetic forces holding the particles within the floor together are resisting the downward pressure from the ball.
What I am saying is that for a ball (or any object) which lies within a gravitational field it must be acquiring energy from somewhere to cause it to move (or try to move.) Since we know from Einstein that gravity is a consequence of spacetime curvature around mass and energy then it seems reasonable to assume that the energy which is giving rise to the gravitational force also comes from the spacetime fabric.
To take the ball analogy further, imagine holding same ball in free space with no gravitational fields ie you are floating in space in a box with said ball. The force required to move the ball above your head would be minimal, you would also have to apply an opposite force to stop the ball once it had gained inertia and was in position above your head. Now accelerate the box upwards with you and the ball being pushed to the floor with force 1g. This is equivalent to being within a gravitational field and the experiment can be repeated with predictable results as on Earth. The difference being that there must be an external application of energy to constantly accelerate the box through space. This energy may come from rocket boosters etc but should this energy source fade then you will return to a zero g 'floating' state.
Where does the gravitational energy which keeps you in a constant state of acceleration on the Earth's surface come from - if not from the energy held within spacetime itself?
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Jean-Luc Picard
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Re: Force Behind Gravity [Re: jonmel77]
#23527370 - 08/10/16 07:22 AM (7 years, 5 months ago) |
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It's not a constant energy input, it is a result of an energy gradient that causes an apparent acceleration, but it is commonly accepted that gravity is not a true "force".
Energy (and thus mass) warps spacetime, and the magnitude of warping is proportional to the amount of mass/energy per unit volume of the body in question. We know this from empirical evidence (photon path length near a massive body, gravitational lensing, time dilation of GPS satellite clocks, etc.
The warping of spacetime can be looked at as a form of energy conservation. The higher the mass/energy present, the lower the "apparent energy", as I'll call it, of the local spacetime. The conservation of energy still applies, as the integral (or total warping) of spacetime is the same as it would be if all particles of the same massive body were evenly scattered throughout the universe. The motivation for the particles to conglomerate together is to satisfy the natural tendency of a particle to move from a state of higher energy to a state of lower energy. So, while the total warping of spacetime is the same, a more massive body allows for all particles to move to the lowest energy state possible.
So, this warping sets up a potential energy gradient, the high point of which is empty space, an infinite distance from any object, and is the same for all particles per unit of mass present, and the local low point is determined by the total mass of the massive attractor being considered. The particle effectively slides down the energy gradient, converting the potential energy to kinetic energy (which btw usually makes up a very small, almost negligible portion of the host particles total enegry/mass), reaching a very predictable final velocity, and eventually impacting the massive attractor, whereby this kinetic energy is converted to either heat (distributed kinetic energy, or chemical energy, or photons and other particles (in extreme cases). This is further proved in the case of mass less particles, which should not be affected by gravity, and yet their direction may be changed by this local energy gradient, where no net energy transfer takes place.
This eliminates the problem that arises with the birth of the first singularity (black hole), around which the gravitational acceleration should become infinite. In your proposed theory, this would have immediately placed the universal energy withdrawal rate to infinite, thus halting time while simultaneously pushing space
Energy is always conserved, and it is not necessary to draw constant energy from a massive reserve that we haven't identified up until this point.
-------------------- The universe is under no obligation to make sense to you - NDT
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jonmel77
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"converting the potential energy to kinetic energy (which btw usually makes up a very small, almost negligible portion of the host particles total enegry/mass)"
General relativity shows that it is the inherent energy/ mass of particles which warps spacetime, which in turn creates a gradient resulting in the force of gravity.
"Energy is always conserved, and it is not necessary to draw constant energy from a massive reserve that we haven't identified up until this point"
The reserve is the energy held within spacetime itself, the gradient across spacetime gives rise to gravity. The energy held within spacetime can be seen more dramatically within nuclear reactions.
Energy is being conserved by converting the energy held within the warping of spacetime into the energy of acceleration of mass (ie gravity).
The reasoning of potential gravitational energy being converted to kinetic energy doesn't actually address where gravitational energy is coming from. Saying that kinetic energy is being released due to matter sliding down the energy gradient of warped spacetime.
How did the gravitational potential energy arise? By the warping of spacetime. Where did the gravitational force come from? Conservation of energy laws tell us that this potential energy must have come from somewhere.
Entropy is also poorly understood in modern physics. Having spacetime provide energy for gravity gives a times arrow which at present is overlooked.
I'm not familiar with the birth of the first singularity. Is this the big bang? Either way a black hole is formed, or originates, when the amount of mass exceeds the warping threshold of spacetime. So that spacetime is warped to its furthest extent ie speed of light. Any additional mass simply pushes the event horizon of the black hole further out. Since the gravitational force is dependent on the extent of warping then it will never go to infinity, even if an infinite amount of mass was held within the blackhole.
Thanks for your responses btw
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Jean-Luc Picard
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Re: Force Behind Gravity [Re: jonmel77]
#23536288 - 08/12/16 09:38 PM (7 years, 5 months ago) |
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I think I understand where you are coming from though (please tell me if I'm wrong):
You are saying that as an object gains kinetic energy from free-fall, part of the energy involved in creating the energy gradient (space-time warping) of the attracting body is imparted on the free-falling body, which manifests as an increase in kinetic energy?
If that is the case, then the sum of the magnitude of space-time warping of both the attracting body and the free-falling body would have to be different between the two states of:
1 - The free-falling body at an infinite distance from the attracting body 2 - The free-falling body after impact with the attracting body
The total magnitude in state 2 would have to be larger than the total in state 1, in order to account for the extra energy imparted on the system by spacetime. If matter is assumed to be conserved during the collision, then the kinetic energy gained from the collision would be converted to heat, and could be considered as part of the energy/matter of the system. Even if the heat is radiated away into space, the total amount of space time warp in the universe would increase, resulting in a net loss of energy from space-time  
But, from what I remember about objects moving in response to energy gradients, they typically move across the gradient carrying a portion of the gradient's energy, which ultimately fills in the gradient unless injection of energy is present to keep the gradient going. Your system seems to move object across in order to create a deeper and steeper gradient, but maybe I'm not looking at long enough timescales, and maybe we are in an epoch of a cascading energy transfer from space-time that will ultimately end in a uniform, lower energy space-time. . . . Well shit man, at this point I'm inclined to do a little research myself, and would definitely encourage you to do more research on the subject. Now as far as the implications (rate of time passage, appearance of expansion), I can't yet comment on that, I'll have to chew on what I just went through, and get back to you in a later post.
-------------------- The universe is under no obligation to make sense to you - NDT
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jonmel77
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the energy gradient (space-time warping) of the attracting body is imparted on the free-falling body, which manifests as an increase in kinetic energy
This is close to what I'm getting, thanks for taking the time for thinking about this.
The free-falling body (which is also warping spacetime, albeit only slightly for small objects) is drawn towards the higher density spacetime created by the attracting body. A force is applied due to the interaction between these spacetime density gradients.
The magnitude of space-time warping falls off according to the inverse square rule so that a free-falling body at an infinite distance from the attracting body would have a very shallow spacetime gradient (tending to zero) across it. Spacetime here would also be very thin (less dense) so that time is moving much quicker, space is more 'spaced out', relative to an object close to a massive body. NB - A low density, or thin, spacetime could also be defined as by a having a lower 'constant' c - speed of light.
A free-falling body at impact with the attracting body would have a steep spacetime gradient across it so would be accelerating faster and converting more spacetime energy into kinetic energy. After impact correct to say this energy is then converted to heat/ new particles etc.
I'm sure the full implications of general relativity and its consequences in the cosmos are not taken into consideration nearly often enough. Take a look at this paper explaining the long standing problem of rotational velocities of galaxies by simply applying general relativity (as opposed to Newton's earlier approximate): http://arxiv.org/pdf/astro-ph/0507619v1.pdf
Consider a galaxy, its centre a super massive blackhole (billions of suns mass). Its farthest reaches a cold, sparse cloud of occasional hydrogen molecules. By GR time and space is denser close to mass, ie the passage of time is slower, space is more squashed together. This is a hard concept to visualise. Looking at a galaxy from a distance is similar to looking through a lense, the centre is all squashed up and the edge all spread out. This can be seen most dramatically with Einstein rings:
 Its dismissed by modern literature because these effects are only supposed to be noticeable at high energies, relativistic velocities, close to black holes.... A galaxy extends all the way from a blackhole out to intergalactic space but on a massive scale (order of million light years) but the difference must still be taken into account because its the relative difference between spacetime densities, not the scale, which has the effect. If spacetime could somehow be flattened out so that we see a galaxy for what it really is then the centre would be huge and the edge would be more squashed together. This is why stars on the edge of a galaxy 'appear' to be moving too fast to be held in orbit around a galaxy. If you could film the rotation of a galaxy over millions/ billions years then stars in the middle would be ageing slower and orbiting relatively slower than those on the edge.
Back to my original post, that spacetime is losing energy, or density, to gravity then older (closer) galaxies will have a lower spacetime density across them. They are evolving faster than galaxies further away (time is moving faster). Considering the Hubble redshift quandary, they also have a shallower spacetime gradient. More distant galaxies have a higher spacetime density and therefore a steeper spacetime gradient. Light leaving a distance galaxy has to travel out of this deeper spacetime well which causes it to redshift.
Time is not uniform across the universe. Regions of high mass move slower through time so that distant parts of the universe are currently observed to be up to 14 billion years old, these are the brightest regions of the early universe with the highest luminosity and presumably the highest mass. Intergalactic zones have much thinner spacetime, time is moving quicker so they might be 20 billion years old or more, who knows exactly because it seems no-one has thought about this or done the required mathematics. However they must be older than current scientific knowledge allows because GR tells us that time is relative and the densest/ most luminous areas of spacetime have been measured.
Time must also be progressively getting faster as the universe ages due to the loss of spacetime energy through gravity as discussed. Time moves slower for distant galaxies relative to here. Globular clusters are another example of extremely old stars found in local galaxies, they live in 'clusters' which indicates how close together they are and how much gravitational energy they hold. Again they are dated close to the 14 billion year old mark. Spacetime here would be very dense and time ticking more slowly so that other less dense parts of the galaxy, such as near our Sun, must be older if relativity is considered properly.
The Cosmic Microwave Background Radiation (CMB) is incredibly uniform in every direction. We see large luminous sources of radiation visible in the early universe but there must also exist more dispersed, more numerous, older and less luminous sources of radiation scattered throughout the rest of the universe. The CMB has been attributed to the recombination of atoms after the big bang. Could the big bang be more drawn out and progressive than suggested if time is considered according to GR here. This negates inflation theory or the dark energy required for an expanding universe.
Maybe the universe just is, neither expanding/ contracting. If anything as entropy increases and spacetime densities decrease the universe will become more diverse, more intelligent and more accessible to its inhabitant lifeforms.
Edited by jonmel77 (08/15/16 04:25 PM)
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akira_akuma
Φύσις κρύπτεσθαι ὕψιστος φιλεῖ


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Re: Force Behind Gravity [Re: jonmel77]
#23544183 - 08/15/16 01:56 PM (7 years, 5 months ago) |
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interesting thread. need more.
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jonmel77
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Well you got more akira!
Also they've just found a 1.3 earth mass planet orbiting around our closest star too, likely with liquid water.
http://www.nature.com/nature/journal/v536/n7617/full/nature19106.html
-------------------- “All matter originates and exists only by virtue of a force which brings the particle of an atom to vibration and holds this most minute solar system of the atom together. We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter.” ― Max Planck
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Le_Canard
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Re: Force Behind Gravity [Re: jonmel77]
#23575970 - 08/25/16 12:41 PM (7 years, 5 months ago) |
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Gravity exists because the Earth sucks. ~me~ /end thread
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