Newton's gravity debunked
The formulation of gravity as a ‘force’ that acts upon the gravitational mass of an object is not supported by experimental observation and leads to theoretical absurdities. The ideas of force, mass, acceleration and even ‘movement’ are ill-defined, vague and not experimentally verifiable.
This post points out the anomalies, the redundancy of the concept of gravitational mass and the inadequacy of Newtonian theory even as a practical measurement system. An alternative way of looking at gravity is proposed which is intuitively superior, theoretically consistent, computationally identical to Newton’s theory, eliminates superfluous variables and provides for a definition of ‘movement’ (and hence ‘acceleration’) as being relative to the local gravitational field.
The narrative
The accepted mechanism of Newtonian gravity is that all objects possess an intrinsic property called ‘gravitational mass’ and that the Earth’s gravity acts upon that mass to produce a ‘force’ which pulls the object downwards. The more mass, the greater the force, which means that one object having twice the mass of another will experience twice the downward force. This downward force results in an acceleration of the object towards the Earth.
All objects fall with the same acceleration
There seems to be experimental evidence that all objects released above the Earth’s surface will fall to the ground with the same acceleration regardless of their presumed mass and that any difference in their speeds is down to air resistance only. Wikipedia
Since all objects in these experiments behave identically regardless of their (gravitational) mass, we cannot deduce anything at all concerning the mass of an object by observing the acceleration of that object in a gravitational field.
We cannot empirically verify the relationship between gravitational mass and downward acceleration because there is no measurable relationship.
This is unarguable.
Theoretical concerns and ‘inertial mass’
Newtonian theory now suggests that there exists another type of mass, an ‘inertial’ mass which ‘resists’ the hypothetical downward force from gravity in exact proportion to such a force. This is the explanation as to why all objects fall with the same acceleration despite having different masses; the inertial mass and gravitational mass are the same and so they both cancel each other out: NASA
From NASA: “(The theoretical) mass of the object does not affect the motion“
Mass is irrelevant according to both theory and experiment
So according to theory, the acceleration is constant and independent of mass. Moreover, according to experimental findings, the acceleration is constant and hence independent of mass.
We therefore have a theory of gravitational mass that has not been verified by experiment and where such experimental verification is actually ruled out by the theory itself!
Therefore, there is not and cannot be, any meaningful discussion of the effects of something called ‘gravitational mass’, because there are no such directly observable effects and nor can such effects be inferred from theory.
Gravitational mass cannot be said to ‘exist’ in any meaningful sense of the word and it follows that the gravitational ‘force’ that is said to be associated with it cannot be said to exist in any meaningful sense of the word.
The downwards acceleration cannot be said to be caused by a ‘force’ and cannot be said to be connected to such a thing as gravitational mass.
The uselessness of Newton’s second law in this respect
The NASA paper gives Newton’s second law of motion as somehow describing the motion of a free falling object:
force = mass x acceleration
This looks more like a definition of something called a ‘force’ than an equation telling us how an object moves, but we can rearrange it to look like this:
acceleration = force / mass
But the NASA paper concludes: “The mass, size, and shape of the object are not a factor in describing the motion of the object“.
We have a nice looking equation, but what use is it? In order to calculate the acceleration we need first to know both the force and the mass. However:
The mass cannot be determined empirically (see above)
There is no way to directly measure the ‘force’ on a free falling object
The acceleration has been empirically determined to be the same for each object
The Newtonian system is formulated around the idea of mass and force as fundamentals and wants to use these as a basis from which to try to calculate secondary quantities such as acceleration. The force and mass are assumed to be the ’cause’ of the acceleration.
However, the only quantity here that is directly measurable is that of acceleration and so why not take this as a fundamental of the system and derive the other quantities from it? The problem is that the acceleration is constant, which means that if this is the only thing that we can measure then there is no chance of deducing anything at all concerning the other quantities and no way to verify Newton’s laws as applying to falling objects.
The ambiguities of Newton’s first law
Newton’s first law from Wikipedia: “A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force.”
This is where the problem lies.
It is simply decreed without justification or precise definitions that if a body is accelerating, then there must be a force acting upon that body. A free falling object is therefore assumed to have a force acting upon it and so even though no force is felt and no force is measurable, a force must be conjured from thin air; the result is the ‘gravitational force’.
Moreover, what does it mean to say that a body ‘remains at rest’? At rest with respect to what exactly? Any object at the Earths surface is said to be rotating with the Earth at thousands of miles per hour and is moving through space at even greater speeds. No object that is observed to be at rest with respect to the Earth’s surface can be honestly said to be ‘at rest’ and so what does the term mean? What is meant by ‘motion in a straight line’ under these circumstances?
What is ‘position’?
There seems to be an implicit assumption that the physical world is superimposed upon some Cartesian grid which serves as a reference frame for position and hence velocity and acceleration, but no such construct has been shown to exist or to be empirically measurable and therefore deserves no place in a theoretical model of the physical world.
Other theoreticians imagine that ‘position’ can somehow be measured with respect to the distant stars and galaxies, but at the same time say that these do not have fixed position and are in fact moving away from us at ever increasing speeds.
Consider what happens when an object is ‘dropped’ in a free falling space station, it doesn’t move with respect to the observer and so cannot be seen to have any forces acting upon it. Advocates of Newton will say that it does have forces upon it and that these are causing it to accelerate towards the Earth. However, the astronauts will not feel any forces upon themselves, cannot measure such forces, cannot directly measure their own acceleration, will not be able to relate any movement (there is no observed movement) of the object to the mass (mass is unmeasurable) of the object.
The astronauts will therefore not observe, and cannot measure any force upon the object. We have a ‘measurement system’ where literally none of the required variables can actually be measured.
A system of measurement?
Newtonian gravity as a description of physical reality seems totally inadequate, but what about regarding it merely as a System of Measurement, i.e. a system of well defined measurement techniques and equations to be used to solve practical engineering problems?
Wikipedia defines a System of Measurement thus: “A system of units of measurement, also known as a system of units or system of measurement, is a collection of units of measurement and rules relating them to each other. Systems of historically been important, regulated and defined for the purposes of science and commerce.”
This sounds like a good idea but the problem with the theory of gravity in this regard is that the fundamental ‘measurable’ of the system is the acceleration of the object and not the mass or force. In fact, both the mass and force are shown above to be unmeasurable and irrelevant to the equation of motion.
The acceleration is not just the fundamental measurable of the system, but the only measurable of the system. An equation of motion in a uniform gravitational field reduces to:
acceleration = g (a constant)
No masses or forces are needed here.
If the gravitational field is variable, the the equation remains the same but with a variable value for ‘g’. Moreover, the value for ‘g’ will be determined by first measuring the acceleration of a free-falling object and inferring ‘g’ from the acceleration and not the other way around.
As far as our system of measurement goes, we only need acceleration as a measurable, with both mass and force being secondary (derived/imaginary) quantities.
An argument for the irrelevance of mass
I forget where this idea comes from:
Consider two apples of equal weight falling towards the ground. They fall at the same acceleration. Move them closer together so that they touch and nothing changes. Now glue them together so that they become one large object of twice the volume/weight/mass. Nothing changes and they continue to fall at the same rate; the amount of ‘matter’ present is irrelevant and the acceleration is always the same.
A field of acceleration?
The results so far suggest that the Earth is surrounded by something we might call a field of acceleration, which causes untethered objects to move towards it with a fixed acceleration.
We can think of an analogy with a river which moves objects downstream regardless of their size or weight. No floating object feels that it is being dragged and none feel a ‘force’ pulling them along. However attempts to pull an object against the stream will certainly require the application of force.
The force needed to pull an object up or down the stream is the force needed to overcome the drag produced by the water and will be the same as the force needed to pull it left or right towards a bank. To rephrase, the force is needed to change the velocity of the object relative to the local flow of the water.
We can therefore consider that the force needed to accelerate an object in a gravitational field is proportional to the attempt to move it relative to the local gravitational ‘flow’.
A gravitational field can be thought of as flowing inwards towards the Earth from space and increasing in its accelerative potential as it nears the Earth’s surface according to an inverse square law. It will ‘drag’ any object towards the Earth in accordance with the local field value of at that point.
Problems solved so far
All problems are solved already.
There is no requirement to create a fictitious quantity called ‘gravitational mass’ only to have it cancel out in the math.
The constant acceleration near the surface of the Earth is regarded as a fundamental of the physical theory and of the system of measurement. Moreover, it is in fact measurable!
Experiments performed in a space station or falling lift are now explained naturally without having to find a balance of complex forces in order to explain a floating object. All objects including the observers are in a force-free space and this is evident by the fact that objects simply float around in mid air.
Acceleration and movement are described relative to local field conditions only. There is no need for a Cartesian grid at the base of physical reality and no need to take into account the movement of distant galaxies. Objects move according to the local gravitational field and any deviation from this movement requires the application of a ‘force’ and so a modified version of Newton’s Law is easily formulated:
“A body remains at a constant speed relative to the local field, unless it is acted upon by a force.”
The phenomenon of ‘weight’ is explained by a scales having to drag or push an object upwards against the local (downward) field flow. The phenomenon of inertia is explained similarly by ‘field drag’; the object is being accelerated against the local field and a force is required. We would expect that in a space station or falling elevator, it would be equally difficult to drag objects in any direction, but it would be nice to see some verification of this.
The equality of inertial and gravitational mass implies that the field is somehow isotropic; it is as much effort to drag the object sideways as it is to drag it upwards (prevent it falling downwards). Compare with dragging an object through a river.
If a deformable float is dragged through a river, it deforms, whereas if it is simply allowed to float downstream, it maintains its form. Similarly, if a balloon full of water is allowed to fall freely in a gravitational field, it maintains its shape, but attempts to accelerate it against the field flow by hanging it from a string or pulling it along a friction-free surface, will cause visible deformation.
We feel heavy because every part of us struggles to move upwards against the constant downward acceleration of gravity. Astronauts in space, however, are moving with the local field flow and hence feel no weight; they are weightless.
An overall vortex structure
The field can be thought of as having an overall spherical vortex structure which intensifies towards the Earth according to the familiar inverse square law. Imagine water flowing down a sink hole to get a picture. The intensity of the field is proportional to the acceleration of matter which increases towards the Earth in the same way that a twig might increase in speed as it flows towards the whirlpool centre.
The intensity of the field is at a maximum at the Earth’s surface and then reduces in a linear fashion towards the centre of the Earth to become zero at the centre. This is the same pattern as the vortex flow in a tornado. The field is rotating at the Earth’s surface at a rate of 360° per day and this ensures that objects released above the surface fall directly downwards and do not drag behind the planet’s rotation. Again, a constant acceleration is maintained relative to the field.
‘Field movement’ and ‘acceleration’ are towards the Earth but intensity diminishes towards the centre of the planet so there is no infinite accumulation of ‘field substance’ at the centre. This may seem odd, but compare with the almost universally accepted explanation of a gravitational field which is continuously ’emitted’, with no explanation of how such emission takes place or how an infinite ‘source’ of such a stuff could exist. Moreover, the field is assumed to somehow move outwards whilst pulling objects back inwards by influencing their unmeasurable (non-existent) ‘gravitational mass’.
The understanding of ‘field movement’ is by analogy with a water wave in which the wave itself appears to move in a particular direction with a particular speed, but no linear movement of the water itself is present. The wave ‘moves’ but nothing really goes anywhere and so there is no need for a ‘source’ of such a field and no infinite sink needed to dispose of the excess.
Variable day length
The length of an Earth day varies on timespans of only a few days (Wikipedia). The day length on Venus can vary by up to 20 minutes. Explanations are in the form of either external forces generated by the other planets or internal forces arising from the motion of liquid metal in the planet’s core. In neither case is it explained how such forces can act upon a whole planet at once without causing catastrophic deformation of the crust and consequent earthquakes.
The problem, then is in attributing the variable rotation speed to things called ‘forces’. Given the hypothesis outlined above, we can now consider that the variable rotation arises from variations in the behaviour Earth’s gravitational field itself and it is this field and these variations which affect the rotational speed of our planet.
Gravity pulls objects directly downwards, towards the centre of the Earth, and not at an angle determined by the rotational speed. If we forget about momentum for a moment (too Newtonian), this implies that the Earth’s gravitational field is rotating along with the surface of the Earth and is continuous with it. We could actually say that it is this gravitational field that is ‘causing’ the Earth to rotate, or maybe that the field preserves the constant rotational acceleration in the same way as it preserves the constant linear acceleration of a falling apple.
If we try to explain the variable rotation in terms of ‘forces’, we need huge forces to move the whole planet. However, an explanation in terms of an acceleration field is, by its very nature, independent of the mass of the planet and arises simply from the dynamics of vortex flow. To get a visual picture, watch some eddies in a stream and observe how their local activity fluctuates slightly in response to both the proximity of other eddies and global changes in the flow as a whole.
In classical physics, gravity, energy and matter are all separate entities and the theory of physics is all about describing how these entities somehow affect each other in a meaningful way. In the vortex physics of Konstatin Meyl, however, even electrons and other fundamental particles are formulated as simple field vortices with energy, matter and mass being emergent properties of the underlying field, the same way that a water vortex is not a separate entity of itself, but a manifestation of the underlying properties of water.
The Earth’s gravitational field, then, spirals inwards from the cosmos and at the Earths surface, fine grained structure appears which is interpreted as ‘matter’. This matter is not separate from the field but ‘is’ the field and the rotation of the Earth is not ’caused by’ the field but is synonymous with it. The persistence of rotation arises from the properties of the field and is formulated as ‘angular momentum’ in classical mechanics.
What is ‘momentum’?
The accelerates objects downwards towards the Earth’s surface because the ‘field movement’ or accelerational component of the field is at right angles to the Earth’s surface and moves along with it. The horizontal component of such a field is zero with respect to the Earth’s surface.
A thrown object will maintain a constant speed relative to the Earth’s surface will therefore maintain a constant horizontal speed and this is interpreted as momentum in classical mechanics. Momentum, mass and inertia are therefore not intrinsic properties of a moving mass but illusions created by the interaction between the ambient gravitational field and the field structure of the object itself.
No Cartesian grid?
There is no underlying Cartesian grid to physical reality; all movement and acceleration are with reference to the local field conditions. There is no need to hypothesise some independent entity called ‘space’ and no need to hypothesise any absolute metrics of distance or even time as all of these are not fundamentals of reality but measurement artefacts that are dependent upon both local field conditions and the precise mechanism of measurement.
‘Distance’ is the length of a ruler, a physical object. Such a length will vary according to ambient field strength (Tamarack mines experiment) and so the distance metric will necessarily vary. The overwhelming desire for an invariant form of ‘length’ in the form of an invisible entity called ‘space’ or even ‘aether’ has caused physicists to assume the existence of such a thing with no proof and to the detriment of scientific progress.
Mach’s principle
How does an object ‘know’ when it is rotating? What is its frame of reference and how do centrifugal forces arise?
The frame of reference is the ambient gravitational field and acceleration is relative to this field as in all cases. The illusion of centrifugal force arises from movement against the local gravitational flow, just as with a falling object.
Gravity as an electromagnetic field
The idea that gravity is in fact an electromagnetic field has been floated by several people including proponents of the Electric Universe model and German physicist Konstantin Meyl.
Meyl gives a modified version of Maxwell’s equations to describe the field as the cumulative average of all of the magnetic dipoles of all of the fundamental particles which constitute the body of the Earth and any object within its ambit. Calculations are given in his book “Scalar Waves: A first Tesla physics textbook for engineers” which give quantitative support to this hypothesis.
What is interesting is that descriptions from Meyl based upon a theory at the atomic level, seem entirely consistent with the model described presented above. The laws of physics are the same at all scales of reality and so careful interpretations of macro phenomena can lead to valid hypotheses concerning reality at the atomic level.
A brief note on causality
Newton’s first law: “A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force.”
Note the implication here of causality; a force is causing a body to change its customary motion and if a body is changing its motion then there must be a force acting upon it.
How do we test this? How do we quantify the forces and accelerations?
Newton’s second law in mathematical notation:
force = mass x acceleration
or
acceleration = force / mass
Note the lack of any sort of causality. We just have mathematical equality in equations where manipulation is according to the laws of mathematics and not the laws of causation. The equations can be reversed left to right and divided either side and the ‘meaning’ remains the same.
There is no symbol for ’causes’ in classical physics, but the equations are always interpreted as somehow encapsulating causality. We therefore have a theoretical framework that is incapable of expressing one of the main ideas of its own inception.
This inevitably leads to confusion. How can we ever prove that it is a force which is causing the motion as opposed to the acceleration of a mass which is causing an apparent force? If a force and acceleration are always co-present then in what sense can one said to be ‘causing’ the other?’. If we can get by with a mathematical framework that does not include the idea of causation, then why did we need such an idea in the first place?
Newton has chosen to essentially invent the concept of a force as being somehow ‘causative’ (of a change in movement) in the Universe but he could just as well have decided that ‘acceleration’ was a fundamental property of objects near a mass and that such an acceleration, if opposed, would lead to a measurable force. The mathematical theoretical framework, containing no concept of causality, cannot possibly refute this idea and so we are completely justified in conceiving of a universe where ‘acceleration’ is primal and (inertial) ‘forces’ are a secondary epiphenomenon.
Summary
The idea of Newtonian gravity as arising from a ‘force’ exerted upon a gravitational mass has been shown to be nothing more than an intellectual conjuring trick, with the mass itself acting as the MacGuffin, a beguiling distraction which has nothing to do with the mechanics of the trick itself and is, in this case, not measurable, not observable and not computationally relevant.
A new way of thinking about a gravitational field has been described which:
Eliminates the anomalies of the Newtonian system
Has no surplus variables
Has no theoretically unmeasurable quantities
Is computationally identical to Newton’s system
.. and is therefore consistent with existing experimental results
Is less confusing to think about
Is consistent with the idea of gravity as an electromagnetic field
Is consistent with the bottom-up theory of Meyl
Is consistent with the thought experiments of Einstein
Relies upon local field conditions only
Requires no imaginary Cartesian grid
Defines ‘movement’ relative to the local field
Has been derived from observations at the macro scale