What if gravity is an emergent phenomenon? So what kind of phenomenon is being discussed in that case?
Like a restoring force beginning to exist the minute an elastic tension starts to stray from neutral (Hooke's law)?
This is exactly what the Coulomb force seems to be at the subatomic level within the electromagnetic structure of photons, according to de Broglie's conditions.
Analyzed in Sections 3.1, 3.2 and 3.3 of this recently published article:
Article Introduction to Synchronized Kinematic and Electromagnetic Mechanics
Here's the answer to your question given by Arthur Eddington.
https://youtu.be/nlDmDPeMw4w
Yet many, even scientists, consider gravity to be a fundamental force - what could be a coherent argument?
All forces in our world are caused by a position dependent energy content. If an object contributes to a force field, the energy content of the field overlay depends on the distance between the object and the field source. The energy content of the field overlay is proportional to the field strength squared.
The field energy dependency on the object position leads to the force on the object. Moving the object along the force direction, reduces the energy content of the field overlay.
This force law holds for all kinds of force fields including gravitational fields.
There is a well-founded suspicion that the electrical attraction of oppositely charged particles is not a causal force of interaction either, but the forceful curvature of space-time.
Wolfgang Konle
When you mentioned fields in general, any interaction field can be described as a curved geometry - including an EM field. It is essential to recognize which is a non-local correlation as a curvature formation and which is a causally delayed curvature update signal.
Esa Säkkinen "When you mentioned fields in general, any interaction field can be described as a curved geometry - including an EM field."
Yes, you can describe the impact of an electrical field by means of a curved geometry. But this does not have a physical meaning because this curved geometry will never bend the propagation of light.
Wolfgang Konle "But this does not have a physical meaning because this curved geometry will never bend the propagation of light."
The net curvature is gravity, of course. But at the atomic level and elementary particles, we can model the bending light of the soliton structure when the basic curvature is not compensated by the effects of the emergence of the neutral structure.
Esa Säkkinen "But at the atomic level and elementary particles, we can model ..."
Yes at the atomic level there are many unsolved problems. One point is why do electrons in atomar orbits not radiate. We must assume that electron shells are static fields without any acceleration.
A curved geometry which could confine point like electrons would be a model pointing to just the opposite direction.
Wolfgang Konle
In the antipolar phased spacetime on a circular path, the action / electron alternately sees the nucleus, interacts with it and transfer back upper, fluctuating on its geodesic as a bound state without emitting radiation. By antipolar phased spacetime, I mean that its structure alternately shifting includes the structure of matter as both normal and antimatter. But the research is in progress and programmed to be completed in 2026.
The thread question “Could gravity just be pure curved geometry, but not a fundamental force?”
- looks as rather strange. Geometry is a mathematical discipline, and so has no relation to what happens anywhere else; though mathematics, including, of course, geometry, is extremely effective tool at description and analysis of what exists and happens in Matter, but it is fundamentally nothing else than only a tool.
Including if some systems of gravitationally coupled bodies are considered, the bodies configuration in Matter’s space is, of course, geometrically described, but again that is only description, while how the configuration exists and changes – that is determined by fundamental Nature forces [in the systems above – mostly by Gravity Force, though at that other Forces can act, say, if bodies are electrically charged, etc.]
Gravity is fundamentally nothing else than one of the Forces. That in mainstream physics now the GR, which is based first of all on postulate that gravitational dynamics in a system of bodies is determined by interactions in systems “mass-spacetime-mass”, is the standard theory, is a quite natural consequence from the fact that in the mainstream sciences, including physics, all really fundamental phenomena/notions, first of all in this case “Matter”– and so everything in Matter, i.e. “particles”, “fields”, etc., “Consciousness”, “Space”, “Time”, “Energy”, “Information”, are fundamentally completely transcendent/uncertain/irrational,
- and really the postulate above is nothing else than a transcendent assumption. Which really is fundamentally wrong – as that rigorously scientifically proven in the Shevchenko-Tokarevsky’s informational physical model 3 main papers are
https://www.researchgate.net/publication/354418793_The_Informational_Conception_and_the_Base_of_Physics,
https://www.researchgate.net/publication/355361749_The_informational_physical_model_and_fundamental_problems_in_physics
https://www.researchgate.net/publication/369357747_The_informational_model_-Nuclear_Force, where all fundamental phenomena/notions above are rigorously scientifically defined,
- Matter’s spacetime is fundamentally absolute, fundamentally continuous, fundamentally flat, and fundamentally “Cartesian”, (at least) [4+4+1]4D spacetime with metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct), which fundamentally cannot be affectedby anything in Matter and fundamentally cannot affect anything in Matter.
So that
“…Yet many, even scientists, consider gravity to be a fundamental force - what could be a coherent argument?….”
- looks as a bit strange claim. Really just scientists consider gravity to be a fundamental force, while yeah, rather numerous other physicists, who think that space/time/spacetime points contain some energy/momentums that depend on “spacetime curvature geometry”, and force , say, Earth to rotate around Sun, really aren’t scientists; and really – especially in last number dozens of .years develop really some transcendent theories, where discover more and more really fantastic “holes”, “channels”, etc., in the Matter’s spacetime.
More about what is Gravity see the Shevchenko-Tokarevsky’s 2007 initial model of Gravity and Electric Forces in section 6. in 2-nd link above, or in
https://www.researchgate.net/publication/365437307_The_informational_model_-_Gravity_and_Electric_Forces ,
Cheers
Dear Sergey Shevchenko
I'm tired of stubborn points of view - here: gravity-inertia cannot be an interaction between matter and the space-time interval structure - no, it must be a force between bodies.
Not all understanding is what the mammalian brain models into concepts.
Esa Säkkinen "...fluctuating on its geodesic as a bound state without emitting radiation."
A movement along a curved geodesic is not necessarily free from radiation.
But with your idea of space curvature in the nano-world, you could be right. I only do not think that space curvature is applicable in the scope of atoms and molecules.
May be stable elementary particles have a tiny kernel with a gravitationally generated 3-sphere space structure. Such a space configuration would lead to an unlimited stability.
No. No cause, no source, no force, no pull, no push, no positive/no negative, no energy, no elements, no places.
Michael Lucas Monterey "No, no, no..."
What is your context? Without context we only can summarize your comment with "no sense".
Dear Esa Säkkinen
“…I'm tired of stubborn points of view - here: gravity-inertia cannot be an interaction between matter and the space-time interval structure - no, it must be a force between bodies.
Not all understanding is what the mammalian brain models into concepts.…..”
- to say about some “understanding” it is necessary before to understand what the word “understanding” means. Really “understanding” of something means that this something is certainly enough defined, and its properties and parameters have rational explanations, first of all at analysis of how this something is linked with/relates to other somethings in some environment.
In physics the environment of any concrete something is/are other somethings in Matter, and everything in Matter exists absolutely fundamentally in the Matter’ space, which has concrete number of concrete just Matter’s dimensions, and happens/changes in the time dimension; so at “understanding” of something in Matter it is necessary also to understand – what are “space” and “time”.
To understand concrete something “gravity-inertia” it is necessary also to understand – what is “inertia” – and what is “energy”.
If somebody understands what are “space”, “time”, “inertia” , “energy” in Matter – what is possible only at experimental, and really reasonable theoretical, studies of Matter, what is made in physics rather essentially, from the existent studies it rather convincingly looks that everything in Matter interacts at acting of fundamental Nature forces – at least of Electric, Weak, and Strong/Nuclear Forces, which by any means interact with space/time/spacetime, and act, correspondingly in flat space/spacetime, for material somethings existence and the Forces acting nothing necessary in the spacetime besides being of some “empty container”.
From the above for any rationally thinking human it looks as completely rational understanding is that observed gravitational objects/events/effects/processes that interact/happen in observed gravitationally coupled systems is result of acting of some, other than the 3 above, fundamental Nature “Gravity” force, which – as the other Forces – acts, of course, also in the fundamentally flat empty container, where these other Force act.
Again, to “understand” that that observed gravitational objects/events/effects/processes are “interaction between matter and the space-time interval structure” it is necessary before to define rationally enough what are “space” and “time”, and for what some rational reasons and by what some rational ways “space” and “time” impact on bodies – and, of course, for what some rational reasons and by what some rational ways the bodies impact on “space” and “time”.
Really now yeah, standard physical Gravity theory is the GR, where the interactions in systems “mass-spacetime-mass” are postulated, however the GR doesn’t contain any rational definitions of “space”, “time”, “inertia” , and “energy”; and any rational reasons and rational ways for/by which “space” and “time” impact on bodies and reversibly. What for anybody, who knows what the word “understanding” means and is able to think rationally, looks that the GR postulate above really isn’t understood in the GR.
More about what is Gravity Force, which is similar in a number or traits to Electric and Nuclear Forces, see the SS&VT 2007 initial physical model of Gravity and Electric Forces in linked in SS post above, 2 days ago now, papers; where, including, the really absolutely fundamental phenomena/notions “space”, “time”, “inertia” , “energy” [and “simply fundamental” phenomenon/notion “Matter”] are rigorously scientifically defined,
- including from these, again – scientifically rigorous – definitions it completely rigorously follows that the postulated in the GR interactions in systems “mass-spacetime-mass” are fundamentally impossible; all that in the model is an example of real understanding.
Cheers
Here on this site I have posted an article "Mass as the geometry of space" Everything is shown there in the drawings available for the 6th grade of the school. We all exist in 3D+2 space. (+2 not time) 3D we can try to feel. +2 - we can't. More precisely, we can but only indirectly through the effects in 3D. Each body (elementary particle) with its mass/volume distorts 3D space in +2 space.
All physicists who describe gravity forget about the second term of mass - inertia. Hence all sorts of nonsense about gravitons, the Higgs boson ...
Gravity = when the body (mutually) rolls into another funnel of space curvature. Inertia = when the body is trying to move out of its own funnel.
Ilya Boldov "Gravity = when the body (mutually) rolls into another funnel of space curvature.
Inertia = when the body is trying to move out of its own funnel."
Gravity
The gravitational force F on objects is given by the dependency of the energy content Eoverlay of the field overlay on the displacement dx of the objects, which cause the field overlay.
F=d Eoverlay/dx.
F=dE/dx is one of the most basic laws of nature. We know it as "work equals force times path-way".
Inertia
The inertial force F on a mass m is given by the dependency of the kinetic energy content Ekin of the mass, on the displacement dx, which causes the kinetic energy modification.
F=d/dx(Ekin)= d/dx(mv²/2)= mvdv/dx= mdx/dt*dv/dx= mdxdv/(dxdt)= mdv/dt= m*a.
F=m*a is the well-known Newtonian force law. We know it as "force equals mass times acceleration".
In all cases the derivative d/dx is a directional derivative vector
d/dx=(∂/∂x, ∂/∂y, ∂/∂z)
Wolfgang Konle
Quite right. Replace the concept of FIELD with the angle of inclination of the vector on the slope of the gravitational funnel. Or external (gravity), or own, where they are trying to "roll" it.
Ilya Boldov "Replace the concept of FIELD with the angle of inclination of the vector on the slope of the gravitational funnel."
Why should we replace the well-known term "field" with something complex, bulky, and unknown like "inclination of the vector on the slope of the gravitational funnel"?
What formula applies to that inclination, which finally leads to the gravitational force?
Wolfgang Konle
F=G*m1*m2/R^2 (m1 =the depth of the alien funnel is proportional to the mass m1 of the first body; 1/R^2= the angle of inclination of the vector at the location of the second body; m2= the magnitude of the vector of the second mass
Zoncita Del Mundo Norman
The basic balance can be seen in the process of accumulation of matter and the process of deformation of space-time, so that in the settled spherical result, the two are connected: space-time, with its curvature, controls the movements of spatiality (gravity), and in bodies of matter, particles press against each other (pressure). In terms of bodies of matter, the surrounding time curvature plays a major role, which means that space flows into the bodies as maintenance for pressure - this flow equals exactly inertia.
Ilya Boldov's description of how gravitation is following a curve and inertia is staying in a curve is an analogy in the right direction, but curvature is not the curvature of space but mainly of time. The significance of the curvature of space can be seen for bodies whose mutual speed is close to the speed of causality c.
The thread question is rigorously scientifically answered in a couple of SS posts on page 2.
To read SS posts about what is really fundamental Nature Gravity force, including what is Gravity field;
why and how the fundamentally different gravitational and inertial masses are equivalent at least at small speeds,
and what is “equivalence principle” in the GR ,
- see SS post in
https://www.researchgate.net/post/Why_is_the_curvature_of_spacetime_so_generally_accepted_as_an_ultimate_truth/12, page 12, 6 days ago now, though to read few SS posts at least on page 11 is quite useful as well.
Cheers
It is interesting that Newton never speculated publically about the nature of gravity. He preferred to state the law in geometric terms, although he regarded gravity as a force. Einstein gave an equivalence between two different context of free fall and the presence of a body. Certainly gravity can be modelled as "a curved geometric line", if one gave a general description. Whether it matches the experiences of everyday life is an interesting question.
Ilya Boldov "1/R^2= the angle of inclination of the vector at the location of the second body". 1/R² does not have the units of an angle. An angle is defined as the difference between two directions. What directions define your inclination angle? In what units are you measuring your inclination angle?
I think the mainstream view amongst some of the more enlightened members of the community is that, as long as space is simply-connected, the "field" description and the "spacetime curvature" description should be exactly equivalent, and should produce precisely the same predictions.
As a question of physics, it then makes no difference whatsoever which approach you take. If the two paradigms are dual, it's pointless to claim that one of them is right, and that therefore the other is wrong.
Of course, you always get some physics people who have been indocrinated in a particular view, and who go around telling others that we know that gravity is curvature, and that there's no such thing as a gravitational field. IMO, these people are best avoided.
The truth is, both concepts have their advantages and disadvantages, and part of what makes someone a skilled theorist is supposed to be the ability to skip backwards and forwards between different paradigms, to find the easiest route to a correct answer. Having more interchangeable paradigms at your disposal is like having more tools in your toolbox, and being able to calculate the same outcomes using multiple methods is a useful way of sanity-checking your results.
This attitude is summed up nicely in the introduction to chapter 11 of Kip Thorne's 1994 "Black Holes and Time Warps" book, "What is reality?" (page 397 onwards):
" What is the real, genuine truth? Is [the presumed spacetime background] really flat [with superimposed fields], or is it really curved? To a physicist like m this is an uninteresting question, because it has no physical consequences. "
Ilya Boldov :
wrt your last post, you are absolutely correct.
The principle of equivalence of inertia and gravitation means that every fundamental massed particle must have a gravitational field.
If the particles have relative motion, the throats of their gravity-wells are then tilted to align with the tilts of their worldlines.
This means that there is reduced curvature between two particles if their worldlines point towards each other, and increased curvature if they point away from each other. So if they approach, there's a curvature-based blueshift, and if they recede, there's a curvature-based redshift.
This velocity-dependent curvature is equivalent to what would be described in field theory as a velocity-dependent gravitomagnetic field.
The tilt can be described as a gravitomagnetic effect, which gives an approaching body a repulsive component and a receding body an attractive component, and has the effect of deflecting nearby matter and light in the direction that the body is moving.
This is the mechanism (described in the curvature domain) that underlies the gravitational slingshot effect, and also the accelerational and rotational gravitomagnetic effects needed for a general theory of relativity.
The velocity-dependent GM field can also be thought of as the moving body's momentum field -- where the "smearing out" of a body's inertia creates a gravitational field, the "smearing out" of its momentum creates a gravitomagnetic field.
This is also the counterpart of the body's momentum probability field under quantum mechanics.
Wolfgang Konle : " Why should we replace the well-known term "field" with something complex, bulky, and unknown like ' inclination of the vector on the slope of the gravitational funnel '? "
Because the geometrical description tells us what characteristics those fields need to have.
Wolfgang Konle : " What formula applies to that inclination, which finally leads to the gravitational force? "
The inclination of the gravity-well's throat to that if the surrounding metric, that leads to the gravitomagnetic force due to relative motion, is simply the inclination of the moving massed-particle's worldline to its environment.
You can assign a time-axis to every point in space between two relatively moving particles, A and B. At A, the time axis points along A's worldline, and at B, it points along B's worldline, and for all points in between, the angle of the time axis takes on intermediate values.
If A and B are large, and we insert a small test mass J somewhere between them, the time-axis orientation for J with be influenced by the alignments of A and B. If J is placed closer to A, its worldline will be influenced more strongly to agree with the worldline orientation of A, and if it is placed closer to B, its worldline will be influenced more strongly to agree with the worldline orientation of B.
Place it closer to A, and it will tend to move in A's direction of motion, place it closer to B, and it will tend to move more in sympathy with B, via momentum exchange.
At the bottom of the well's throat, the round-trip speed of light is symmetrical for the particle (local c). The particle doesn't see is own proximal field to be distorted. As we get further away from the particle, the tilt (wrt background) fades away and the gravity-well's orientation takes on the orientation of the average background field, with the influence of the source mass on light becoming weaker with distance.
This is the new physics.
If gravity is curved geometry the consequence is that there must exist gravity and also anti-gravity (opposite curvature). The fact that Einstein’s theory of General relativity is widely accepted shows that most physicists prefer the universe as an open model. In spite of the universal conservation laws (energy and momentum).
The image above shows the Bose-Einstein Condensate. I have used the image in a couple of other topics because it seems that not everybody is aware of this ground braking experiment some 25 years ago (it made the headlines all over the world and it is described in the text books).
The experiment is about a closed vessel with a limited number of gas atoms. If we extract as many electromagnetic amplitudes/waves from the volume inside the vessel, the result is a temperature that nears 0 degrees Kelvin. Now all the individual atoms are transformed into one electromagnetic quantum configuration. Thus there are no atoms, no nuclei (rest mass), no electrons, there is no gravitational field of the atoms, there are no decreased scalars of the Higgs field, etc. There are only the amplitudes of the electromagnetic field.
The consequence is that the electromagnetic field represents all the dynamics in the universe and gravity is just an emergent force field. In other words, gravity isn’t pure curved geometry and it isn’t a fundamental force either.
If we want to describe the geometry of space we have to describe the geometry of the distinct basic quantum fields. Because “space” is just a general term that can be described in more detail with the help of the experimental derived properties of the basic quantum fields. In practice, space is just volume.
With kind regards, Sydney
Some thoughts on anti-gravity.
* As the satellite gains more speed, it rises to a higher orbit
* When a body expands, it rises higher in the medium because its density decreases
Antigravity equals buoyancy and gravity equals lack of orbital motion (debt).
All acceleration is anti-gravity and those who don’t accelerate think they are subject to the fundamental force; gravity.
Earth is a planet that accelerates us upwards. The denser you are the slower you anti-gravitates. Lighter materials accelerates (anti-gravitates) faster and that’s why our planet has atmosphere.
But hold on - when a body is accelerated, it's needed to use energy and/or throw away something. What do all planets and stars and bodies throw away for anti-gravitating? Each others - but a curious way: space expands over all globally.
That’s the story what the theory of general relativity tells us - but do we believe? Mostly not. Almost all experts think too that gravity is a fundamental force to be quantized. We see with clear eyes: gravity is fictitious force opposite to interaction forces implying acceleration = anti-gravity. Only the curved spacetime needs to be quantized in its metric.
Esa Säkkinen
Then the following is obtained:
1. The atmosphere rotates with the planet.
2. The higher from the surface of the planet, the higher the orbital speed of air masses.
3. The higher from the surface, the lower the density of the atmosphere.
Then it turns out that if the density of the balloon is less than the density of the air on the surface, it rushes up, trying to take a place with the same density of the atmosphere around as inside it (adjusted for the load).
I still don’t understand how to connect this with the position of the molecules of the atmosphere (more precisely, its density) on the gravitational funnel, but it turns out that at close distances in gravity, it is necessary to take into account not only the mass of bodies and the distance between them, but also the shape of the gravitational funnel dictated by the density of the body.
If all the dynamics in the universe originate from the electromagnetic field – and gravity is the cause of a change of position and a change in time – gravity as an emergent force field must be mediated by the universal electric field or by the magnetic field. Both are corresponding fields (termed “electromagnetic field”).
If it is the universal electric field the velocity of the influence of the gravitational field is the speed of light. But now the “nature” of gravity cannot be a pull force like Newtonian gravity because the universal electric field is a 3D topological field because it has a structure. Thus gravity must be a push force from vacuum space around matter.
If gravity is mediated by the magnetic field the velocity of the influence of the gravitational force is instantaneous. In line with Newtonian gravity and in line with the meaning of the creation of rest mass in modern QFT. Because in QFT rest mass is directly related to the decrease of the magnitude of one or more local scalars within the concentration of energy (the particle). The consequence is the vectorization of all the scalars of the flat Higgs field around the particle (vacuum space) and all the vectors point towards the rest mass of the particle. Now gravity must be a vector force – super positioned on the vectors of the magnetic field – and anti-gravity cannot exist.
There is an interesting paper about the velocity of the influence of the force of gravity:
“The speed of gravity – What the experiments say” [Tom Van Flandern – Physics Letters A 250: Issues 1-3, December 1998, pages 1-11] https://doi.org/10.1016/S0375-9601(98)00650-1 https://www.sciencedirect.com/science/article/abs/pii/S0375960198006501?via%3Dihub
The experiments of Louis Rancourt and Philip Tattersall show that gravity is a push force from vacuum space around that can be partly shielded with a “sheet” of electromagnetic waves:
Louis Rancourt and Philip J. Tattersall: "Further Experiments Demonstrating the Effect of Light on Gravitation". Applied Physics Research; Vol. 7, No. 4; 2015 http://dx.doi.org/10.5539/apr.v7n4p4
Like Chungpin Hovering Liao (2019) shows in relation to microwaves: “Microwave-caused influence on gravitational constant G in Newton’s gravitational law”. DOI: 10.13140/RG.2.2.15509.37600
With kind regards, Sydney
One can question why Einstein’s theory of General relativity is in line with many experiments.
One reason is that a vector field around matter shows the same geometrical curvature if we connect all the points on the vectors with the same magnitude. The result looks like “curved space”.
But the Theory of General relativity proposes that the gravitational field (“space”) is curved because of a local concentration of energy (matter). But that is not a reasonable conclusion. Because it is the universal electric field that will be curved if inside the volume exists a concentration of energy. Not at least because the universal electric field has a structure. Thus a resultant curvature of variable properties is mathematically reasonable.
In my previous comment I described the influence of the Bose-Einstein Condensate on the “tangible” individual properties of atoms. However, if we supply energy to the Bose-Einstein Condensate all the previous properties of the atoms of the gas will reappear. That shows that the universal electric field is capable of reconcentrating energy. Actually, it is the cause behind E = m c2.
That means that concentrating energy is the “nature” of the universal electric field and also the nature of the gravitational field. So if we describe the geometrical properties of the universal electric field in relation to matter and we use the gravitational constant G in the equations, who will notice the difference?
So it is not difficult to speculate that Einstein’s theory of General relativity describes the universal electric field if we replace the gravitational constant G with the constant of the universal electric field.
With kind regards, Sydney
Sydney Ernest Grimm "So it is not difficult to speculate that Einstein’s theory of General relativity describes the universal electric field if we replace the gravitational constant G with the constant of the universal electric field."
The energy density of the gravitational field is given by W= -g²/(8πG). If we replace G with the Coulomb constant kC, we get with W=E²/(8πkC) the energy density of the electric field. There is no speculation.
A virtual particle is a nice example of the influence of the electric field to concentrate energy in vacuum space. That means that the electric field tries to minimize its local energy density and the result is the creation of local concentrations of energy.
The gravitational constant G expresses the mutual influence of matter objects in vacuum space (macroscopic reality). The consequence is that the gravitational constant G is the sum of the influence of the force of gravitation and the influence of the “concentration force” of the universal electric field.
But both forces are not “clean” (that means without influences). For example an atmosphere around a planet changes the magnitudes. Moreover, a vector forces (push force) keeps its spherical shape, thanks to the instantaneous influence. But a topological field like the universal electric field is a bit comparable with a fluid and the constant speed of light is a limitation to the reach of the influence in vacuum space. For example the solar system moves with a velocity of about 368 km/s in relation to the rest frame of the electromagnetic field.
So it is difficult to imagine that there are nice constants with exact values. At least not in practice.
With kind regards, Sydney
Sydney Ernest Grimm "So it is difficult to imagine that there are nice constants with exact values. At least not in practice."
No it is not at all difficult to imagine that there are nice stable constants with exact values in any inertial rest frame. Just in practise there is a definite reason for an absolute stability. It is even obligatory that those nice stable constants are all the same in any inertial rest system.
The anthropic principle explains that. This principle, based upon our own existence, proves that there has been a biologic evolution during a long period.
The complex molecular logistics of metabolic processes now requires those nice stable constants. Even the tiniest deviations of these constants would disturb the balanced metabolic processes. It would be sufficient if a single molecule would reduce its stability, for making impossible a complete production chain of vitally important molecules. Even enhancing the stability of a single molecule could poison an important step in a synthesizing process. Because of its horrendous complexity the network of linked metabolic processes would react extremely sensitive on the tiniest modification of the premises of any individual network node.
We see that relativity theory has revealed the physical principle, which just leads to that fundamental stability of molecular properties in any inertial reference system. Without this fundamental principle of relativity, modification of the velocity or the position above sea level would be lethal for any living being.
Wolfgang Konle Wolfgang, your arguments are completely correct from my (constants of nature centric) point of view!
iSpace theory shows and enforces strict exact integer geometric values for all constants of nature, and yes - of course independent of reference frame:
As derived by iSpace theory, the first of its kind able to give exact integer geometric results based on its strictly non-continuous hybrid 10D spacetime model (3D+6D+1D) allowing for simple multiplicative iSpace-SI (V,A,s,m yet still fully SI lab compatible) but more so new iSpace-IQ unit system (the first of its kind to do away with any human artifacts whatsoever) derivation of the quantum of time to be 1/6961 iSpaceSecond exactly in iSpace-iQ units.
These results show, how spacetime needs to be treated mathematically to achieve unification of gravitational and electromagnetic force, which reveals itself and shows to be one and the same, by the application of so called „changed distance definition“ (leading naturally to discretized LEGO style geometry with minimum length 1 (one) and circular number Pi3=3.
For the more open-minded ones, please have a look on my RG home for the following simple to follow (Mathematica based) breakthru iSpace papers:
Method iSpace - Quick check of α and Φ0 from Markoulakis & Antonidakis
Preprint Hubble constant H0 is derived from Newtonian gravitational c...
Conference Paper iSpace - Deriving G from α, e, R∞, μ0 and Quantum of Gravita...
Conference Paper iSpace - Exact Symbolic Equations for Important Physical Con...
Article New novel physical constants metric and fine structure const...
The question is about the relation between gravity as a pure geometrical curvature and its proposed existence as an emergent force(field).
The geometrical curvature of "space" cannot be true if the influence of gravity has the constant speed of light. Because the influence of gravity envelopes an enormous volume of vacuum space. So how is it possible that a planet in motion (our solar system has a velocity of 368 km/s) can force this enormous volume to keep a spherical geometry? That is only possible if the velocity of the gravitational (self)influence is instantaneous. But that is not what Einstein's theory of General relativity predicts.
If Einstein's theorie of General relativity isn't about gravity but about the resultant curvature of the universal electric field, we face the same problem. The velocity of every quantum of energy has the speed of light. So there is no nice resultant geometrical curvature of the universal electric field that represents the "concentration force".
But you need this nice geometrical curvature otherwise you cannot derive an exact constant. Because an average value isn't equal to a constant in theoretical physics.
Anyway, the last comments about "physical constant" originates from my remark that Einstein had enclosed the gravitational constant G in the equations of his theory. But if his theory is about the universal electric field "he needed another constant". But this remark was not meant to start a discussion about the existence of a universal constant that represents the "concentration force" of the structure of the universal electric field.
With kind regards, Sydney
The shape of spacetime is a balance between timelike and spacelike content, mediated by lightlike causal signaling i.e. interactions. Gravitation is not a fundamental interaction but an emergent dynamics resulting from the aforementioned balance. Therefore, mass and gravitation are one and the same - a spreaded correlation. Even a subtle gradient in the shape of spacetime follows the momenta of energy densities according to the law of inertia - only temporal structures pushing each other away from their geodesics lead to delayed corrections in updates to the curved shape of spacetime. The non-local persistence of the shape of spacetime is fundamentally based on the fact that it has taken its shape as matter accumulates, and if the accumulation settles down, the shape, being bound to the accumulation, is part of its momentum, following the curvature of a higher hierarchy. Stars and planets do not therefore maintain gravity, but it is an equal correlation - also it can be said that the curved space-time maintains stars and planets...
What about mass? Do you think it's fundmental or emergence?
"Could gravity just be pure curved geometry, but not a fundamental force?"
Never ever !!
Christian G. Wolf "Wolfgang, your arguments are completely correct from my (constants of nature centric) point of view!"
Of course, I appreciate your agreement to my arguments, but I do not share your "constants of nature centric point of view".
Especially I do not see the Hubble constant among relevant natural constants.
See: Preprint What gravitation really is
Wolfgang Konle Of course: Hubble constant H0 is not a primary but some (multiplicative) aggregated constant, which is really easy to see in my iSpace papers on this (which also has gotten quite some recognition and support):
Preprint Hubble constant H0 is derived from Newtonian gravitational c...
iSpace theory does a pure reductionist approach to show up the absolute mathematical minimum input (integer geometry in form of small prime numbers like identified quantum of time 1/6961 in iSpace-IQ unit system and true geometrical input like Pi (Eklidean 3.14...), the GoldenRatio (1.61...) as well as novel "changed distance definition" based LEGO style integer circle goemetry with Pi3=3 (think 6 cells around 1 center cell, all equally sized).
What it does not do, is intentionally explain, endorse or reject spacetime geometric models, that - however - given simple multiplicative predictive power of iSpace model everyone will surely come to their own conclusion, if something that simple is able to allow precise predictions of constants of nature when not backed by actual spacetime geometry, one way or another.
Wolfgang Konle With respect to your link, I do not see any field theoretical approach useful (like todays QM and relativity). Both are "just" very good approximations of reality: some physically existing ether. This has been rejected for very wrong reasoning and everything is a material particles, producing waves in superluminal particle ether when moving and interfering.
Christian G. Wolf "With respect to your link, I do not see any field theoretical approach useful (like todays QM and relativity). Both are "just" very good approximations of reality: some physically existing ether."
Sorry, I do not see what you are talking about. The approach in the linked article is the negative energy density of gravitational fields, combined with the rule that an absolute negative energy density cannot exist.
We can define force as interactive body change being "antigravitating" buoyancy and fictitious force as a relative state of motion in antigravitating noninertial frame of coordinates being "gravitating" free fall.
Hence, bodies do not gravitate but spacetime defined by motions gravitates - and, spacetime does not antigravitate e.g. as spatial expansion but bodies antigravitate.
Lightest cells antigravitate the most: it's expanding space due to the pressure of matter accumulations.
Any logic contradictions?
Esa Säkkinen , You are looking for the physical cause of gravity. But whatever that cause is, gravity is still a force.
The cause of gravity is unknown, but I'm quite satisfied that curved geometry is not the cause. Something actually has to actively pull two bodies together, and if we have an inflowing aethereal medium acting as an intermediary, we still need to have something that pulls the aether down into the sinks.
Frederik, You just have faulty premises - and there are too many of them. Just try to answer my last question and show my mistake.
The thread question is already rigorously scientifically answered in a couple of SS posts August 23, 25, page 2; if briefly:
- the postulated as real in the GR interactions in systems “mass-spacetime-mass” are fundamentally impossible; and really are postulated illusion of the author, who
– as that was in those times and is till now in the mainstream philosophy and sciences, where all really fundamental phenomena/notions, first of all in this case “Matter”– and so everything in Matter, i.e. “particles”, “fields”, etc., “Consciousness”, “Space”, “Time”, “Energy”, “Inertia”, “Information”, are fundamentally completely transcendent/uncertain/irrational,
- had only some transcendent/uncertain/irrational imagination about what these phenomena/notions – and so the actualizations of “Space”, “Time”, “Energy”, “Inertia” as Matter’s “space”, “time”, and “mass” - are.
Really any really scientific consideration of any physical problem, including what is Gravity problem, principally is possible only provided that all the fundamental phenomena/notions above are really scientifically defined; what is possible, and is done, only in framework of the really philosophical Shevchenko-Tokarevsky’s 2007 “The Information as Absolute” conception, recent version of the basic paper see
https://www.researchgate.net/publication/363645560_The_Information_as_Absolute_-_2022_ed ;
- and concretely at application to Matter in the Shevchenko-Tokarevsky’s informational physical model, links to 3 main papers see in the SS post August 23.
Including Gravity is fundamentally nothing else than some fundamental Nature force, which acts in Matter’s fundamentally absolute, fundamentally continuous, fundamentally flat, and fundamentally “Cartesian”, (at least) [4+4+1]4D spacetime with metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct), which fundamentally is nothing else than infinite by space/time definition “empty container” where everything in Matter placed, exists, and interacts; and which fundamentally cannot be affected by anything in Matter and fundamentally cannot affect anything in Matter.
The rigorously scientifically grounded Shevchenko-Tokarevsky’s Planck scale 2007 initial model of Gravity and Electric Forces is presented in the links in SS post August 23, for convenience repeat one link here:
https://www.researchgate.net/publication/365437307_The_informational_model_-_Gravity_and_Electric_Forces .
More see the SS posts and links in the posts; here only note also that even in the GR – and, of course, in the claims in some posts in this thread about some “materially acting geometry”, there are no any rational explanations of – so how space/time/spacetime impact on material bodies – and oppositely – how material bodies impact on the space/time/spacetime?,
- while at that from observations how everything in Matter exists and happens quite evidently it follows that everything does that only in some empty container; and if space/time/spacetime would affect by some ways particles, atoms, molecules, bodies, etc., Matter would be rather strange…
Cheers
Esa Säkkinen , You have asked me if there are any contradictions in your theory of gravity. Your theory doesn't explain gravity, so contradictions are irrelevant.
If you think you have an explanation for gravity, then explain, in a way that people will understand, how an apple falls to the ground.
F. Tombe,
"My theory" is General Relativity taken ultra seriously so that the curved intervals in the spacetime are as physical as matter bodies.
Esa Säkkinen
After reading your reply to Frederick David Tombe, I have formulated a few questions.
Could you please tell us the difference and/or lack of difference and/or similarity between "curved intervals in spacetime" and "physics matter-(energy) bodies"? Or, do you think that there is any difference at all? If there is no difference at all, then why to use terms like "physical matter bodies", when we already know that matter does not exist alone and energy is already therein? Or, would energy be just the quantities that we assign to "something", and energy-carrying wavicles (or particles or waves, as you may take them) do not exist at all?
In case one thinks that energy-carrying wavicles do not exist, can we say that energy and mass (not merely matter, but matter with certain relatively contextual mass) are inter-convertibly related by some proportions?
NOW TO YOUR LEAD-QUESTION FOR DISCUSSION:
"What if gravity is an emergent phenomenon? So what kind of phenomenon is being discussed in that case?"
Do you mean by 'emergent' something that does not exist like physically existent processes, or phenomena that do exist? Do you identify 'phenomenon' with existent physical processes? And now I would like to know from your pen, whether you mean by gravitation as a, "emergent" 'phenomenon' anything that physically exists, or something that is just a theoretical construct?
I ask such questions not to irritate anyone. I am earnest about clarity in the words being used. Even if it is Einstein that talked about curved spacetime, he should clarified (and he has not) WHETHER he meant by curved spacetime something existent or just existent in theory! This would have avoided more than a century of confusions in physics, cosmology, and philosphical theories of physics!
BUT I HOPE YOU WILL NOT GIVE ME A REPLY LIKE: "You just have faulty premises - and there are too many of them. Just try to answer my last question and show my mistake."
Esa Säkkinen , First of all, General relativity is just the transverse version of the Lorentz transformation, applied to the escape velocity in a gravitational field. And since the equations are simply that of the transverse Doppler effect, a physical explanation is required in order to explain why these equations can be applied as they are in General relativity.
General relativity does not therefore explain gravity. It might describe gravity, but a physical explanation is required to account for gravity's connection to the transverse Doppler effect. Any attempt, however, at such an explanation can only be partial. We can never ultimately explain the source of the force that pulls the apple to the ground.
One thing is sure though, and that is that the force of gravity is not explained by fair phrases like "curved geometry", or "emergent phenomenon", that ultimately mean nothing. And at any rate, I don't subscribe to Einstein's warped space idea. I would see a radial gravitational field more as an aether sink.
Remember, Einstein made an appalling blunder when he discarded Maxwell's aether in 1905, and the fact that he appeared to back-pedal in 1920 didn't help matters any, because his (erroneous) warped space idea pertained to the gravity medium and not to the luminiferous medium. Einstein's warped space did nothing to further the study of the nature of electromagnetic radiation, and neither did it bring us any further along in the quest to better understand gravity.
I can say that a simple question can prove that the idea that the time of relativity can change is wrong. In 1971, two scientists flew with four cesium clocks, and the eastward clock flew slower than on the ground, and the westward clock flew faster than on the ground. But how did these two scientists know that the atomic clocks on planes were slower or fast than those on the ground? The plane needs to be parked on the ground, and then the two scientists can compare the atomic clocks on the plane to the upper atomic clocks on the ground to know the result.But is the atomic clock removed from the plane still in motion?not have! So, why is the reading different from the atomic clock reading on the ground? Aren't these atomic clocks in the same place? Why is the time so different? This is easy to deny the theory of relativity.
Frederick David Tombe
In your opinion, is there anything wrong with Maxwell's equations? Einstein, after all, was inspired by the constant speed of light from Maxwell's equations.
Frederick David Tombe
In my opinion, time invariance and space invariance are physical axioms, and relativity violates this axiom, making it incompatible with quantum mechanics and Newtonian mechanics.The view of time and space is the foundation of physics, the most basic things, if two physical theories have different views of space and time, then they are certainly incompatible, no matter how hard we try, they can not be unified.
Frederick David Tombe "If you think you have an explanation for gravity, then explain, in a way that people will understand, how an apple falls to the ground."
A generally understandable explanation is as follows:
The gravitational fields of the apple and of earth overlap. The field energy content in the overlap region depends on the heigth above sea level. Moving downwards means to reduce the energy content in the field overlay. This is the reason for the gravitational force on the apple.
The general force law is as follows:
The force on an object, which contributes to a force field, is given by the dependency of the energy content in the field overlay on the distance between the object and the field source.
This law holds for all kinds of force fields including the gravitational field.
Duan Xian Xiang , Maxwell believed that light propagates through a physical medium, and that the speed, relative to that medium, is based on its density and elasticity, much as is is the case with all waves.
Maxwell's theory has no connection at all to Einstein's theories. In fact, Einstein removed Maxwell's light carrying medium.
It would seem that Einstein, despite his own claims, had very little knowledge concerning the contents of Maxwell's original papers. The two of them weren't working remotely along the same lines.
Wolfgang Konle , That was just a tautology. Gravitational potential energy is defined from gravitational force, so you can hardly explain a force on the grounds that it is an energy gradient.
There are too many tautologists around these days explaining unknowns in terms of other unknowns.
You need to accept that there are things out there that we will never be able to explain. Gravity is one of them.
It's a bit like this. Imagine five men sitting around a tea table at a meal. There is a hole in the middle of the table, but it is covered over with the table cloth. Unbeknown to the five men, there is a sixth man hiding under the table. At one point, he takes hold of the table cloth from under the hole and gives it a sharp downward tug. The table cloth, as well as all the crockery and cutlery, crash down through the hole.
The five men sit there attempting to explain what they have just observed. One man suggests that the table cloth was maybe warped. Another man suggests that it was the curved pattern on the table cloth that maybe did it.
But none of them dare even suggest looking under the table to see if there was someone down there, because to even as much as suggest the idea, would be tantamount to admitting that they had actually contemplated the possibility.
It's the same, even with most of those who believe that gravity is tied up with an inflowing medium. None of them dare acknowledge that there would still have to be a deeper cause to explain what is actually pulling the aether down.
Frederick David Tombe "You need to accept that there are things out there that we will never be able to explain. Gravity is one of them."
What do you not understand from the reasoning that energy modification ∆E dependent on a displacement ∆s leads to a force? The law is F=∆E/∆s. Or vice versa ∆E=F*∆s known as energy equals force times path-way. This is the basic principle of mechanics. This law is conformal to the force law of a steel spring with spring constant D.
The energy E stored in the spring is E=Ds²/2. s is the displacement from the position at rest. We get the force F to be F=dE/ds=Ds, the force law of a steel spring. This is physics for beginners.
With this simple force law we can explain all forces in our world including the gravitational force. With your oracular claim you are off track in an embarrassing way.
Frederick David Tombe
In fact, the Sagnac effect has proved that there is an ether, but physicists do not admit it.
Duan Xian Xiang "In fact, the Sagnac effect has proved that there is an ether, but physicists do not admit it."
No, the Sagnac effect does not prove the existence of an ether. The Sagnac effect is fully explainable with relativity theory.
There are many paradoxes in electromagnetism, and if there is a medium as a frame of reference for it, then these paradoxes disappear, relativity emerged because Einstein wanted to explain these electromagnetic paradoxes, but it is better to explain with the reference frame of the medium than by relativity.
Wolfgang Konle
The interferometer stripe of the interferometer of the Sagnac effect has changed, which indicates that the relative speed between the light wave and the display has changed, the relative speed change indicates that the constant speed of light is wrong.
Wolfgang Konle
Some say that the Sagnac effect is because the light path distance changes, which is impossible because the ring is divided into two halves, and the two semicircles pass the same distance no matter how the ring rotates. The interference stripe is calculated based on the optical path difference, the two "semicircles" pass the same distance, the same time used, the optical path difference becomes different, the only explanation is that the speed of the light has changed.
Duan Xian Xiang
Look at "Wikipedia, Sagnac effect" The explanations there are well comprehensible and state that the Sagnac effect is conforming to relativity theory.
Wolfgang Konle
I know their calculation is that "the mirror of the inner wall of the fiber leads to the change of the journey", which is nonsense. No matter how the fiber rotates, the distance between the light source and the display is fixed, and the proportion of the distance between the two half circular rays is fixed
Wolfgang Konle , You are only describing forces using mathematical language, but you haven't actually explained the force of gravity. You haven't explained why the apple is pulled to the Earth.
Wolfgang Konle
I want to emphasize that no matter how the ring rotates, the two light waves travel the same distance (or in fixed proportions), because the relative position of the light source and the display is fixed. The distance of the light wave is calculated by the distance between the light source and the display screen plus the angular speed, It doesn't matter how the light wave is refracted in the fiber, because how the light wave is refracted in the fiber has nothing to do with the distance. It does not matter how the light waves move in the fiber, because the distance has nothing to do with how the light waves move in the fiber.
Wolfgang Konle
It is certainly consistent to explain the theory of relativity, because the method of relativity is to change time and space, while the speed is constant. This can be justified, because the relationship between time, speed, distance, can keep one of them as a "ruler", the equation can hold, relativity keeps the speed unchanged and time and space variable, of course, the calculation can also meet. However, this does not mean that the theory of relativity is correct, Because it changes the physical axiom that time cannot change. Without denying the axiom that the time of relativity can be changed, one cannot prove that relativity is wrong, because any doubt against it can be explained by "time, space expansion".
Frederick David Tombe
The axiom of "time can change and space can change" must be denied, otherwise any question of relativity can be solved by "time and space expansion".Even more, relativity can use "time inflation" to justify the Sagnac effect.
Duan Xian Xiang "Without denying the axiom that the time of relativity can be changed, one cannot prove that relativity is wrong, because any doubt against it can be explained by "time, space expansion"."
You cannot proof that relativity is wrong, because it is correct. There is even an anthropic reason for relativity to be correct.
With the locally constant speed of light, all constants of nature are locally constant. Therefor all chemical properties are locally constant. Without this universal property, the molecular logistics of metabolic processes would fail with every movement.
Relativity being correct is essential for the existence of life.
Wolfgang Konle
Then please prove that: time can change. Can you prove it?
Frederick David Tombe "You are only describing forces using mathematical language, but you haven't actually explained the force of gravity. You haven't explained why the apple is pulled to the Earth."
What did you you miss in my explanation about the energy in the field overlay?
The gravitational fields of the apple and of earth overlap. The field energy content in the overlap volume depends on the heigth position of the apple. Moving downwards reduces the energy content in the overlay volume. This energy dependency on a vertical movement is the reason for the gravitational force on the apple.
We all know the force law "energy equals force times path-way". This law explains all forces, including the gravitationa force.
Wolfgang Konle
The clock takes it to the same position to compare the time? So, do they show the same time when compared at the same location?
Wolfgang Konle
If relativity cannot prove that time can change, then relativity cannot prove by the principle that time can change that the Sagnac effect is changed by the interference stripe caused by time change.
Duan Xian Xiang "Then please prove that: time can change. Can you prove it?"
We can proof it as follows:
We syncronize two atomic clocks, then transport one of them to a significantly higher elevation. After let us say one week we bring the clocks together and read them out with a commonly triggered signal.
We will find that the read out values are different. If we repeat the experiment without bringing one of the clocks to the higher elevation we find a significantly smaller deviation of the readout time values.
Wolfgang Konle
Why do their time readings appear different when they are put together? Isn't it all in the same place? Whether it is time or the "flow rate" of time, the atomic clock should theoretically measure it. Why do two atomic clocks measure different "time" or "time velocity" in the same location?
Wolfgang Konle
Taking the atomic clock down from a higher altitude, it should immediately read the same as the clock on the ground, rather than slowly making the two clocks get smaller or even closer, because then they are at the same altitude, and the reading should be the same. Or else an atomic clock is broken.
Duan Xian Xiang "Taking the atomic clock down from a higher altitude, it should immediately read the same as the clock on the ground"
No, the procedure is (1) synchronizing, (2) separating, (3) waiting one week, (4) putting to the same location, (5) read out with a common trigger signal.
Point (3) significantly desynchronizes the clocks on different altitude.
Wolfgang Konle
Are they time synchronized when they are placed in the same position?
Duan Xian Xiang "Are they time synchronized when they are placed in the same position?"
No, the clocks have been time synchronized and then separated. They run during one week on different altitudes. This de-synchronizes them. The de-synchrinisation then is proven with the clocks transported to the same location.
Wolfgang Konle
Two clocks are placed in the same place, no matter what happened before that, and they should now be synchronized, because they are in the same frame of reference, in the same place, in the same gravitational environment.
Wolfgang Konle
But when they are really out of sync, so what does that say? If the two atomic clocks are inconsistent in the same place, it shows that the practice of measuring the time with the atomic clock is wrong from the beginning,It shows that the atomic clock can not measure the time, the reading of the atomic clock is not the time, the atomic clock only represents the time, it cannot measure the time, because the time does not exist, how can it measure the time? Time is human fiction, human fiction time and stipulate that it cannot be changed, because it is used as a ruler to measure the speed of the movement of matter, the ruler can not expand and shrink, otherwise it is not accurate, and Einstein obviously broke the ruler of time.
Duan Xian Xiang "But when they are really out of sync, so what does that say?"
You easily can verify that the clocks remain synchronized if they are not separated to different altitudes.
How is pure curved geometry not a fundamental force?
What is a "metric expansion of space"?
Is there a force behind the observed metric expansion of space? What is that force? Indeed, dark energy, Λ, is meant to supply it, yet "what is it", what is Λ as a force, a presumably fundamental force?
Wolfgang Konle , You have failed to explain what pulls the apple to the ground.
For anyone seeing reality for the first time, the biggest mass apple wins, in attracting other weaker lower mass apples. The question there is how mass thence becomes the "center of the universe and all its associated effects" as a theory of cosmology. That begets the two door knocks of GR theory, dark energy and dark matter, to make GR sensible.
But what is intended by: "For anyone seeing reality for the first time, the biggest mass apple wins, in attracting other weaker lower mass apples"?
Frederick David Tombe "You have failed to explain what pulls the apple to the ground."
No, you simply ignore or misunderstand my explanation. Please tell me what detail you do not understand in the following explanation based on field energy density, which is proportional to the field strength squared.
The gravitational fields of the apple and of earth overlap. The field energy content in the overlap volume depends on the heigth position of the apple. Moving downwards reduces the energy content in the overlay volume. This energy dependency on a vertical movement is the reason for the gravitational force on the apple.
We all know the force law "energy equals force times path-way". This law explains all forces, including the gravitationa force.
Raphael Neelamkavil , what was the intention of the so-called big bang? Is that a fair question?
Wolfgang Konle , You are trying to explain a gravitational field in terms of the overlap between two gravitational fields. That is a tautology.
You need to first explain the gravitational field in isolation. In other words, you need to explain why the apple falls to the ground. You haven't done that yet.
Frederick David Tombe "You need to first explain the gravitational field in isolation."
No, you cannot do that because any gravitational field of an object is an overlap of all the fields of atomic ingredients of the object.
Dear Doctor
Go To
Gravity, Geometry and Physics
J.W. van Holten
Lectures presented at the Summerschool of Theoretical Physics, Saalburg (Germany), Sept. 1996
" Newton's law of gravity is valid for any two massive bodies, as long as they are far apart and do not move too fast with respect to one another. In particular, it describes the motions of celestial bodies like the moon circling the earth, or planets orbiting the sun, as well as those of terrestrial objects like apples falling from a tree, or canon balls in free ight. Ever since Newton this uni cation of celestial and terrestial mechanics has continued to impress people and has had a tremendous impact on our view of the universe. It is the origin and basis for the belief in the general validity of physical laws independent of time and place.
The first step in describing a local fi eld, both in electrodynamics and gravity, is to specify the potentials. The force on a test particle at a certain location is then computed from the gradients of these potentials. In the case of gravity these quantities have not only a dynamical interpretation, but also a geometrical one.
Notice, that the gravitational acceleration does not involve the mass of the test particle. This is the mathematical content of the famous equivalence principle, which states that in a fixed gravitational field all bodies fall with the same acceleration, independent of their mass.
What is still lacking here of course is a set of equations determining the fi elds or potentials in terms of given sources, like Maxwell's equations allow one to compute the electromagnetic fields in terms of charges and currents. General relativity provides such equations; they are known as the Einstein equations, and they determine the gravitational fi elds arising from given distributions of mass-energy and momentum"
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Energy