Acceleration
of the inherent motion in space. How can gravitation be explained
in a spatiomaterial world? To be adequate, it must explain not only the acceleration
due to gravity that Newton recognized, but also all the new phenomena predicted
by the general theory of relativity. That is a challenge, because it must
do so without appealing to spacetime. How can gravitation be explained with
nothing but two opposite substances that exist only at the present moment?
As in the reduction of special relativity, there is no need to
reject the mathematical equations or the interpretations by which they are
tested empirically. All that needs to change is what we take them to refer
to. Since we shall be starting from the assumption that space is absolute,
this is to take an approach opposite to Einstein, just as we did in explaining
special relativity.
Einstein called his explanation of gravitation a general “theory
of relativity” because he assumed that gravitational phenomena, like all other
phenomena, must obey the same laws in every reference frame, and his strategy
was to explain gravitation by describing a way of transforming coordinates
assigned by observers on different reference frames into one another that
leaves the laws of physics unchanged. He assumed that the velocity of light
has the same value in every reference frame, and a tensor calculus was required
to formulate the mathematical transformation.
As ontologists, however, we start by assuming that space and
matter are substances existing in time, and since that means that light may
have different (one-way) velocities, different reference frames are not ontologically
equivalent. Thus, it is not appropriate to call it a theory of relativity.
On the contrary, it will explain the general equivalence of reference frames,
or the premise of Einstein’s argument, as an appearance constituted by space and matter
as ontological causes, much as it did in explaining the premises of Einstein’s
argument in STR.
The key to the spatiomaterialist theory of gravitation is its
explanation of the apparent truth of STR.
In its ontological explanation of the truth of the special theory,
spatiomaterialism rejects Einstein’s assumption that the velocity of light
is the same relative to every inertial frame and assumes, instead, that it
is due to an inherent motion in space. It also assumes (or shows) that the
motion of material objects through space causes four Lorentz distortions in
them. The Lorentz distortions enable it to explain why inertial frames are
empirically equivalent locally, and by taking into account how clocks are
mis-synchronized on moving reference frames by adhering to Einstein’s definition
of simultaneity at a distance (that is, ignoring the difference between the
one-way velocities of light in each direction), they also explain why inertial
frames appear to be equivalent globally, that is, why the (net) Lorentz distortion
always seem to be occurring in the other member of any pair of inertial frames.
These assumptions and conclusions are all taken for granted
in explaining the truth of the general theory of relativity, and only one
additional ontological assumption is required to explain gravitation. That
is the assumption that the accumulation of matter at certain locations
in space has an effect on space, mediated by the inherent motion in space,
that, in effect, accelerates the inherent motion in the nearby space toward
it.
There are various consequences of this assumption. They are
described in the following sections, including their role in explaining the
new phenomena predicted by Einstein. One consequence has to do with the velocity
of light. Another has to do with effect on material objects that are forced
to remain at rest relative to space itself in a gravitational field. The third
is a result of how the effect of matter accumulation on space is mediated
by the inherent motion itself. Finally, I will show how it explains the special
phenomena that occur in very strong gravitational fields, such as black holes.
At the end, I will return to the issue about the nature of the argument and
show how this ontological explanation of gravitation explains “general relativity”
in the sense of the observational equivalence of different models of GTR,
which Einstein used to derive his conclusions.
In constructing its theory of gravitation, spatiomaterialism takes
its lead, as Einstein did, from the assumption that reference frames free-falling
in gravitational fields are equivalent (locally) to reference frames in inertial
motion. Einstein called this the “principle of equivalence.” But given its
explanation of the truth of STR, this principle has a somewhat different meaning,
for spatiomaterialism holds that different inertial frames, despite being
observationally equivalent, are
ontologically different.
When inertial frames have different velocities relative to one
another, at least one must be moving relative to space, and since that means
having a velocity relative to the inherent motion in space, we had to assume
that material objects suffer Lorentz distortions as a result of their motion
relative to the inherent motion in space, in order explain why they appear
equivalent (locally and globally). Now, in order to explain all the old and
new gravitational phenomena, we must assume yet another
interaction between space and matter — an interaction that makes it appear that free falling frames are observationally
equivalent, locally, to inertial frames outside gravitational fields.
Whereas Einstein took gravitation to involve an interaction between
matter and spacetime, spatiomaterialism takes gravitation to involve an interaction
between matter and space. Spatiomaterialism assumes that, instead of curving
spacetime, accumulations of matter (mass and energy) change the velocity of the inherent motion
in space.
I am speaking as if the inherent motion were something actually
moving though space while space endures, as a substance, through time, but
I have admitted that, if you prefer, it can be taken as just a spatio-temporal
aspect of substantival space having to do with how fast what occurs in one
location in space can affect what happens elsewhere. If space is to mediate
the relations and interactions among bits of matter, some such limit on the
velocity of their effects on one another is necessary, because otherwise spatiomaterialism
would have to give up its assumption that space is a substance made up of
many particular substances (one for each location in space and all connected
as described by Euclidean geometry). There is no doubt that space involves
an “inherent motion” in the sense of having a spatio-temporal aspect about
how parts of space are related.
The only issue is whether there is anything actually moving
through space other than bits of matter. That can be doubted, because, thus
far, at least, the only candidates for what moves across space are bits of
matter. Setting material objects aside (because the move slower than the inherent
motion), we have, thus far, come across nothing that actually moves across
space at that maximum velocity except light (and the forces exerted by material
objects with an electric charge), which are forms of matter. The gravitational
force is not an exception, for even though it also propagates at the velocity
of the inherent motion, it is also a form of matter even on this theory (as
I suggested in Forms of matter). But
it does no harm to think of this aspect of the nature of space as an inherent
motion, for we have already recognized that space is a substance enduring
through time and seen that it must have a spatio-temporal aspect to the relations
of its parts. Moreover, in explaining how quantum mechanics can be true in
a spatiomaterial world, we will find that something other than matter also
moves across space with the inherent motion.
Thus, I will continue to speak of space as if there were an
inherent motion through every location, moving at the same velocity both ways
in every direction in three dimensional space. It is something we can imagine,
because as rational beings, we are able to think about space, time and motion,
and thus, it will enable me to describe the effect of matter accumulation
on space in a qualitative way, in terms of its effect on the inherent motion
and, thereby, on all the electromagnetic interactions that are mediated by
it.
Those with a more reactionary bent may, however, want to call
the inherent motion in space by its traditional name. It is actually an ontological
explanation of the ether. The luminiferous ether was supposed to be a material
substance of some kind at rest in absolute space that mediated electric and
magnetic forces like a very elastic material substance. To be sure, we have
no need to postulate any form of matter to play the role of the ether, because
we take space to be a substance, and its inherent motion can mediate electromagnetic
interactions. But on the other hand, it would be appropriate to speak of the
inherent motion in space as the ether, and that means that the new assumption
being made here could be described just as well as an acceleration of the
ether. (I would use this term, except that it is likely to inflame the
antagonism of Einsteinians, who sometimes like to portray their denial of
absolute space as merely discrediting a foolish metaphysical belief in unobservable
entities.)
The assumption that spatiomaterialism makes in order to explain
gravitation, therefore, is that the accumulation of matter exerts a force
on other nearby bits of matter by way of its effect on the inherent motion
in space that changes the velocity of the inherent motion in space as if the
inherent motion itself were being accelerated toward the center of gravity
at the rate described by Newton’s law.
The inherent motion flows both ways in every direction, and the
gravitational change in the velocity of the inherent motion is different in
opposite directions. The inbound velocity of the inherent motion is greater
than it would be outside the gravitational field, and the outbound velocity
is correspondingly less than it would be outside. Thus, it is as if the inherent
motion itself had an inbound velocity.
Since the inherent motion is a velocity both ways in every direction
at every location in space, there is always some pathway for material objects
relative to it in which the two one-way velocities of inherent motion are
equal in both directions. Let us call that motion relative to space “rest
relative to the inherent motion” (or for reactionaries, “rest relative to
the ether”). The effect of the force of gravity is, therefore, equivalent
to accelerating rest relative to the inherent motion in space, so that it
has velocity relative to space in a gravitational field.
(It might, therefore, be better to describe the effect of the
force of gravity as accelerating the ether, because it is rest relative to
the ether that is undetectable. But that could be misleading. It might suggest
that ethereal matter is accumulating at the center of gravity, whereas the
inherent motion is just the way in which bits of matter coincide with space,
and thus, the acceleration of the inherent motion is just a change in how
bits of matter coincide with space. But it is useful to keep in mind that
there is an inertial frame at rest relative to the inherent motion, and it
is, in effect, what is accelerated by the accumulation of matter.)
The inbound velocity of the inherent motion at any point depends
on how much it has increased as a result of accelerating all the way in from
infinitely far away as a result of its acceleration.
The amount of acceleration varies directly as the product of
the amount of matter (mass and energy) making up the objects accelerating
one another and inversely as the square of the distance between them in space
(though the force is exerted by way of the inherent motion).
At any point in a gravitational field, therefore, the increase
in the inbound velocity of the inherent motion is equal to the escape velocity
at that point. That is, relative to space, the inherent motion is moving toward
the concentrated matter at the velocity of light plus a velocity that is equal
to the outbound velocity a material object would have to have at that point
relative to space to escape gravity and eventually come to absolute rest outside
its influence. The decrease in the outward-bound velocity of the inherent
motion in space is likewise the escape velocity, making the outward bound
velocity of the inherent motion the velocity of light minus a velocity equal
to the velocity a material objects would have to have to move outward and
just escape the gravitational filed.
Since the gravitational variation in the velocity of the inherent
motion at different points in space is equivalent to the acceleration of the
inherent motion, any matter that coincides with space by way of the inherent
motion also accelerates at the same rate. That includes, as we shall see,
all forms of matter.
Photons are accelerated because they coincide with space in
such a way that they are carried along by the inherent motion in space.
Material objects also coincide with space by way of its inherent
motion. This is implicit in the spatiomaterialist explanation of the truth
of STR. What makes it impossible to detect its velocity relative to the inherent
motion experimentally are Lorentz distortions that material objects suffer
because of their motion relative to the inherent motion. Indeed, some of those
distortions depend on the difference in the one-way velocities of light in
opposite directions in the direction of its motion relative to the inherent
motion. Thus, when the inherent motion itself is accelerating inward, any
material object that coincides with space by way of the inherent motion is
also accelerated in the same way. And since electric charges move with the
material objects and exert their forces by way of the inherent motion, their
electric fields are accelerated along with them.
Since acceleration of matter by way of the acceleration of the
inherent motion is a form of potential energy, the gravitational field is
itself a form of matter. It is the form of matter I called “gravitational
matter” at the beginning of the ontological explanation of the truth of the
laws of physics (see Forms of matter),
and the quantity of matter involved in constituting the potential energy of
gravitational field is counted as part of the total matter (mass and energy)
accumulated at the center of accumulation. Thus, as the kinetic energy of
material objects increases because of their acceleration, the potential energy
not only declines, but becomes less than zero (or maximum potential energy),
and the total quantity of mass and energy is, thereby, conserved.
If the center of matter accumulation itself is in motion relative
to space, then it already has a velocity relative to the inherent motion in
space and all the effects of its gravitational field are affected accordingly.
Gravitation involves, according to this ontological explanation
of the truth of the general theory, a second interaction between space and
matter. The first was the reaction of space to material objects that acquire
a high constant velocity relative to the inherent motion: it imposes the Lorentz
distortions on such material objects. The second is more complex, because
matter first causes a change in space, and then space, in turn, causes a change
in matter. That is, accumulations of matter accelerate the inherent motion
in space toward themselves, and the acceleration of the inherent motion not
only accelerates the bits of matter it contains, but also changes the velocity
of light at any point in space (because the inherent motion accumulates inward
velocity over the entire gravitational field). It is as if space had a compound
effect on the matter it contains, because either effect can occur separately,
and both can happen at once.
The first effect occurs separately when material objects have
a constant velocity relative to the inherent motion outside of a gravitational
field.
The second effect occurs separately when material objects are
at rest relative to the inherent motion being accelerated into a center of
mass that is at rest in absolute space.
Both effects occur either when material objects have a constant
finite velocity relative to an inherent motion that is being accelerated into
a center of gravity that is at rest, or when the accumulation of matter itself
has a constant velocity relative to the inherent motion in space outside gravitation.
Let us consider the consequences of this additional assumption
about the nature of space and matter.
This ontological assumption explains why Newton’s law is approximately
true in all those areas where it is recognized to be a good approximation,
because it differs from Newton’s theory only in its assumption that gravitation
acts by way of the inherent motion, that is, that it accelerates the surrounding
inherent motion in space and that it does so as a force that is itself propagated
by that inherent motion.
It also explains Einstein’s equivalence principle ontologically.
It entails that local experiments on free falling frames come out the same
as on inertial frames outside gravity, for in both cases they have a constant
velocity relative to the ether.
But the spatiomaterialist theory also explains intuitively certain
new phenomena used to confirm Einstein’s GTR, including the three new kinds
of phenomena that have been used to confirm the general theory as well as
the predictions about black holes.
Variation
in the velocity of light. The most immediate effect of the acceleration
of the inherent motion is on the velocity of light. The photon coincides with
space by having some direction in the inherent motion wherever it is located
and being carried along by the inherent motion in space. Thus, the motion
of the photon relative to space manifests the inherent motion in space any
motion that the inherent motion itself has relative to space because of the
gravitational field.
Since the inherent motion is different at different locations
in space as a function of the force of gravity, a photon traveling inward
toward the center of matter will accelerate as it moves, acquiring a velocity
relative to space that is higher than the velocity of light outside of the
influence of gravitation. Correspondingly, a photon moving outward will leave
the center of mass with a velocity relative to space that is less than it
would have outside of gravitation, and it will accelerate all the time it
is moving outwards until it reaches the velocity of light outside gravitation
just as it escapes the gravitational field.
The quantity of the increase (decrease) in the velocity of light
at any point in space relative to what it would be if there were no gravitational
force depends on the escape velocity, that is, how much velocity a bit of
matter would acquire as a result of being acted on by the gravitational force
as it moves across the gravitational field.
Consider for simplicity’s sake a center of matter (mass and energy)
that is at rest in absolute space. The theory is that when matter accumulates
in space, it acts on the surrounding space in a way that is equivalent to
accelerating the inherent motion in space toward it, giving the inherent motion
itself a velocity relative to absolute space. The rate of acceleration is
determined by the force of gravity (which declines as the square of the distance
from the center of gravity), and that means that the photon starts accelerating
infinitely far away from the gravitating body and accumulates speed as it
continues to accelerate inward (with its rate of acceleration becoming greater
as the gravitational force increases), so that at points nearer the center
of gravity, the photon has an instantaneous, inward velocity that is equal
to the velocity of light outside gravitation plus the escape velocity at that
point in the gravitational field.
If the gravitating body is not at rest in absolute space, but
is itself moving relative the inherent motion in space, that will also alter
the velocity of light the same way at every point throughout its gravitational
field.
When enough matter accumulates to accelerate the inherent motion
itself to a velocity in space that is faster than the velocity of light outside
any gravitational field, it is called a “black hole.”[1] The so-called Schwartzschild radius of a black
hole at rest in space is the surface in space at which the inward velocity
of the virtual inherent motion equals the velocity that light would have in
that direction at that location, if the inherent motion were at absolute rest.
Inward-bound light crossing that surface would have a velocity relative to
space twice what light would have outside of gravitation, and thus, it is
impossible for light being carried in the opposite direction by the inherent
motion to cross that surface. Outward bound photons at the Schwartzschild
radius of a black hole would be at rest relative to space.
Gravitational bending of light rays. The effect
of the acceleration of the inherent motion on the velocity of light explains
the most famous new prediction of the general theory, namely, the bending
of light rays in a gravitational field.
Given that light, as a form of energy, has a mass and exerts
a gravitational force, Newton’s law can be used to predict that light will
be bent from its straight path by the force of gravity, much like a material
object. But the general theory of relativity predicts that the light ray will
be bent at about twice the rate predicted by Newton’s theory. And in a famous
expedition in 1918, Eddington found that Einstein was correct by measuring
the direction of a ray of light from a distant star as it passed behind the
sun during an eclipse and the distant star could be seen.
The greater effect of gravitation predicted by Einstein is what
would be expected on the spatiomaterialist explanation of gravitation, because
two factors are involved in determining the pathway of the photon.
First, as the light ray passes the gravitating body, it is pulled
sideways into the center of gravity by the inward acceleration of the inherent
motion in the transverse direction, which diverts it from a straight path,
much as expected on Newtonian grounds.
Second, as the photon is approaching the center of gravity,
the inward acceleration of the inherent motion gives light an inward velocity
higher than it would have outside the gravitational field. But since the inherent
motion on the other side of the center of gravity has been accelerated in
the opposite direction, the photon slows down as it passes the gravitating
body to a velocity that is lower than it would be outside gravitation, and
then it gradually speeds it up again to the normal velocity of light relative
to space as it moves out of the gravitational field on the other side. The
result of these changes in the velocity of light is that the photon spends
a disproportionately longer period of its entire trip near the center of gravity
where the sideways acceleration of the inherent motion toward the center is
greatest than it does farther away when the sideways acceleration of the inherent
motion is minimal. That explains the higher value of bending predicted by
Einstein.[2]
Time delay in radar signals. The effect of the acceleration
of the inherent motion on the pathways of photons can also explain the time
delay in radar signals reflected back to earth from planets on the far side
of the sun when the paths of those signals lie near the sun.
There is a spatial symmetry
about the velocity changes that occur both times the radar signal approaches
and recedes from the sun. The signal gains velocity as it approaches the sun,
because the inherent motion is accelerating under gravity in that direction.
But it quickly comes to have a lower velocity than light outside of gravitation
as it passes by the sun, because of the inbound acceleration of the inherent
motion on the other side of the sun. And then the signal regains velocity
as it recedes, because the inward velocity of the inherent motion on the other
side is lower the father away from the sun.
It might seem that there should be no net effect on the total
time it takes for the light signal to pass by the sun, because the higher
velocity of its approach to the sun will be canceled out by the lower velocity
of its retreat from the sun on the opposite side. After all, the approaching
signal travels just as far at each
higher velocity as the receding signal travels at comparably lower velocities.
There is, however, a net slowing down of the period required
for the entire trip, because the equal distance on each side of the sun entails
that the light signal spends more time
traveling at slower velocities than it does traveling at faster velocities.
Hence, it cannot make up all the time it loses going slower in the time it
spends going faster. This happens both ways on its round-way trip to the distant
planet, causing an overall delay in the radar signal’s return that does not
occur when its path is not near the sun.[3]
Time
dilation caused by acceleration relative to the inherent motion. Another
famous prediction of Einstein’s general theory of relativity is the so-called
“gravitational red shift,” or a time dilation in gravitational fields. That
is, all physical processes on material objects are slowed down at a rate that
depends on the potential energy of the gravitational field (which would vary
directly with the altitude, if the force of gravity were constant). It predicts
that such a time dilation will be observed both in objects at rest in a gravitational
field and in objects in free fall in a gravitational field.
Gravitational time was observed by Pound and Rebca (1960) demonstrating
a difference in the rate of oscillation of iron nuclei at the top and bottom
of a tower at Harvard.
It was also observed in signals sent by a hydrogen maser shot
up above the earth and allowed to fall back by Vessot (1980).
Gravitational time dilation can be explained by the spatiomaterialist
theory of gravitation, but it implies that physical processes are actually
slowed down only when material objects are at rest in a gravitational field.
Objects in free fall in a gravitational field are not affected. But there
is an appearance of a time dilation in objects in free fall that is caused
by the change in the velocity of the light by which the speed of falling clocks
is observed. Let us, therefore, consider each case separately.
Real
gravitational time dilation. The principle of equivalence implies
that material objects at rest in a gravitational field will suffer a time
dilation, and the ontological explanation of the equivalence principle according
to the spatiomaterialist theory of gravitation implies that the rate of time
dilation is proportional to the energy that would be required to accelerate
the object to keep in at rest given its velocity relative to the inherent
motion.
This distortion is like the Lorentz time dilation, except that
it depends on resisting the gravitational acceleration of the inherent motion
rather than having a constant velocity relative to it. According to the spatiomaterialist
theory, a clock at rest in a gravitational field, for example, will be slowed
down compared to a clock in free fall. If a free falling clock happened to
have an initial upward velocity in a gravitational field like a ball thrown
into the sky and it was synchronized with a clock at rest on its way up, then,
when it passed the same rest clock again on its way down, the rest clock will
have fallen behind by an amount that depends on the period between the measurements
and the energy required each unit of time to resist the acceleration of the
inherent motion and keep it from falling in gravity, given the velocity of
the accelerated inherent motion at that point.
The “gravitational red shift” in objects at rest is usually explained as a consequence of Einstein’s equivalence principle. Consider two clocks at rest at different altitudes in a gravitational field and what happens to a regular signal (such as photons of a certain frequency) sent between them, say from the upper rest clock to the lower. (See Diagram of Gravitational red shift.) The equivalence principle implies that, when this interaction is observed from a free falling frame, it must obey the same laws that hold for inertial frames outside gravitational fields.
Consider, therefore, a free falling frame as long as the distance between the two rest clocks, and suppose that it had been shot upwards so that its inertial motion brings the top of the free falling frame momentarily to rest in space alongside the upper rest clock just as it sends a photon of a certain frequency toward the bottom rest clock. If the photon were intercepted by the bottom free falling clock, it would have the same frequency observed when it left, because that is what would be observed if the inertial frame were outside the gravitational field. But that is not how the photon would appear to the bottom rest clock, as can be predicted by observers on the free falling frame. All the time that the photon is traveling downward, the free falling frame is also accelerating downward, and thus, when the observer at the bottom of the free falling frame sees the photon being received by the bottom rest clock, that clock will be moving upward toward the photon. Such motion would cause a Doppler effect, and so the free falling observer predicts that the photon will be measured by the bottom rest clock as having a higher frequency than the photon sent by the upper rest clock. Indeed, this is what the rest observer does find, according to GTR and actual experiment.
In this case, it is a gravitational blue shift, but if the signal
had been sent upward, it would be a red shift. (By the time the photon arrived
at the top rest clock, the free falling frame whose bottom clock was momentarily
at rest beside the bottom rest clock when the signal was sent would have accelerated
downward, and so the top free falling observers would see the top rest clock
as receding upward when the signal arrives, entailing the prediction of a
Doppler red shift, that is, a lower frequency of light received by observer
located by the top rest clock.)
What is the cause of the red/blue shift observed by the receiving
rest clock?
GTR explains the frequency change by the spacetime curvature
between the two clocks, but it does not say whether it results from a change
in the frequency of light signals during the flight or a difference in the
intrinsic rates of rest clocks at different altitudes. Will (1986, p. 49-50)
says that “it doesn’t matter” whether the “light signal changes frequency
during the flight” or the “intrinsic rate . .
of the clocks change”, because there is “no operational way to distinguish
between the two descriptions”.
Spatiomaterialism, however, cannot be indifferent, for it assumes
that space and matter are substances that exist only at the present moment,
and that means that the red/blue shift cannot involve any actual change in
the frequency of signals as they travel across space through time. The frequency,
or period between signals, cannot change, regardless how the velocity of light
may change along the path, as long as each signal follows the same path
in real time. The only possible spatiomaterialist explanation is that
the frequency shift is an appearance due to an actual slowing down of the
rest clock (and all processes involving material objects at rest).
Spatiomaterialism explains why the clocks at rest are slowed
down by their relationship to the inherent motion. The inherent motion is
accelerating at the location of the clock, which is evident in the free falling
frame, and thus, the rest clock must be accelerated relative to it in order
to keep it at rest. In order to understand the relationship between these
two reference frames, let us consider the equivalent situation outside of
gravitation according to the spatiomaterialist theory.
The relationship between these two reference frames in the gravitational
field is not equivalent to one reference frame being accelerated relative
to some inertial reference frame outside gravitation unless both frames are
also in motion relative to the inherent motion in space, because at any point
in a gravitational field, the inherent motion has acquired a certain velocity
relative to absolute space. Thus, let us consider two reference frames outside
of gravity that have the same velocity relative to the inherent motion as
those in the gravitational frame, and let us suppose that one of them is accelerated
relative to the other. In such a case, the Doppler effect would cause the
same red (or blue) shift, depending on which way one frame was accelerated
relative to the other during the brief interval of measurement.
Outside a gravitational field, the Doppler effect would not
be interpreted as a time dilation, because it would be explained by the change
in the velocity of one of the frame relative to the inherent motion due to
its acceleration during the interval of measurement. The situation in the
gravitational field is different because the acceleration of one frame relative
to the other does not change the velocity of either one of them relative to
the inherent motion.[4]
Instead, it is the inherent motion itself that is being accelerated. Thus,
the red (or blue) shift cannot be explained as a result of the change in velocity
relative to the inherent motion due to the acceleration of the frame at rest
in gravitation, as it is outside gravitation. It can only be the result of
a slowing down of physical processes on the reference frame at rest in gravitation.
Thus, it is a real time dilation.
Rest clocks at different altitudes in a gravitational field
suffer different rates of time dilation, even though they may be resisting
the same rate of acceleration in the inherent motion (as in a uniform gravitational
field). This can be explained on the spatiomaterialist theory, because they
have different velocities relative to the inherent motion. Outside a gravitational
field, according to Newtonian physics, different amounts of energy are required
for the same acceleration in objects when the objects have different velocities.
The force per unit time is the same, but since at higher velocities, the force
must be exerted over a greater distance, and thus, the energy consumed in
exerting the force over that period of time is greater. That is, the rate
of gravitational time dilation is proportional, not the force required to
accelerate the rest clock, but to the amount of energy required. (At lower
altitudes, the force has to act over a greater distance relative to rest in
the inherent motion in order to keep the clock at rest.) This explains why
the rate of time dilation is proportional to the potential energy for its
location in the gravitational field (or the kinetic energy an object falling
from outside the gravitational field would have at that point).
Apparent
gravitational red shift. An actual gravitational time dilation occurs
only when the clock is being accelerated against the acceleration of the inherent
motion. A clock in free fall in a gravitational field will actually tick away
at the same rate as a clock outside of the gravitational field. But a clock
free falling in a gravitational field will appear to suffer a gravitational
time dilation, because the motion of the clock across the gravitational potential
means that any signals it sends out at regular intervals will be received
later than they are expected, making it seem like the clock is slowed down.
Consider a clock in free fall sending signals out of a gravitational
field. To observers outside the gravitational field, those signals will make
it appear that the clock is suffering a time dilation, though it is not, because
in addition to the normal Doppler shift expected from the velocity it acquires
from free fall, signals sent back from lower altitudes will also travel the
additional distance at lower velocities
of light because the outbound velocity of light is lower (because the
inbound velocity of the inherent motion is greater the closer it is to the
center of gravity). Each signal will be delayed a bit longer than expected.
Or consider a clock shot upwards in a gravitational field that
sends regular signals to earth (Vessot’s experiment). The signals received
from the clock on earth will be affected by several factors apart from gravitation,
including its location at the moment the signal is sent and its instantaneous
velocity. These factors can be calculated and compared with the signals actually
received. The actual signals will seem to be arriving sooner that expected
the higher the clock goes, making it seem that the clock must be speeding
up as it rises out of the gravitational field. But that is not proof that
objects in free fall suffer a time dilation. Instead, it merely indicates
that the light signal is traveling faster toward earth than the velocity of
light outside of gravitation, and the higher the clock rises, the more different
this factor makes (though the effect
decreases as the altitude increases, because the signal travels the additional
distance at a velocity that is closer to what it is outside gravitation).
The spatiomaterialist explanation of gravitational time dilation
in general relativity resembles its explanation of the global equivalence
of inertial frames in special relativity, because in both cases it recognizes
both real and apparent distortions.
In special relativity, the Lorentz distortions are real in inertial
frames that are moving relative to the inherent motion. But to observers on
such a moving inertial frame, the inertial frame at rest relative to the inherent
motion appears to be suffering Lorentz distortions. (The appearance
is caused, as we have seen, by the mis-synchronization of clocks on the moving
inertial frame and how that combines with its real Lorentz distortions.)
In general relativity, the gravitational time dilation is real
material objects that are at rest in a gravitational frame, because that is
how accelerate reference frames are related to the inherent motion. But free
falling clocks appear to be suffering a time dilation, because as the clock
falls, the signals travel pathways from the clock to the stationary observer
at various velocities that are either faster or slower than the velocity of
light outside of gravitation, depending on where the is located when the signal
is sent.
Propagation
of the gravitational force through the inherent motion. The final famous prediction of Einstein’s general
theory of relativity is precession of the perihelion of Mercury’s orbit around
the sun As Mercury orbits the sun,
the main axis of its elliptical orbit rotates slowly around the sun (in the
same direction as Mercury itself). It is a very small rotation (about 43 seconds
of an arc per century, setting aside the other perturbations that Newtonian
physics can also explain. This phenomenon also has an explanation in terms
of the acceleration of the inherent motion in space according to the spatiomaterialist
explanation of gravitation.
The gravitational force is exerted by a center where matter has
accumulated by way of the inherent motion, that is, at the outbound velocity
of light in the inherent motion it affects. The force is like a pulse of attraction
propagating outward from the gravitating body, accelerating the inherent motion
toward itself wherever the pulse reaches. The force is steady, because one
pulse follows another continuously. But the gravitational force exerted anywhere
in the field imposed by these pulses is exerted locally, by the inherent motion
though which matter of any kind coincides with space at that point.
Gravitational waves. It helps to have a concrete
model of how the gravitational force is exerted, and so let us think of it
as being exerted by a flow of outbound pulses through the inherent motion
affecting the velocity of inherent motion itself that it passes through. That
will enable us to see why there are gravitational waves, as predicted by Einstein’s
general theory of relativity.
When a gravitating body is at rest in space, its force field
is basically spherical. The center of matter exerts a gravitational force
on the surrounding space by way of the inherent motion (at the velocity of
outbound light in it), and the acceleration it imposes on the inherent motion
itself falls off at the square of the distance. Though the acceleration felt
at any point in the gravitational field depends on a force that started propagating
from the central body earlier, the acceleration at that point does not change
over time, because each pulse of gravitational force is followed by another
pulse the next moment.
At any point in the field, the arrival of a gravitational pulse
accelerates the inherent motion inward (increasing its inbound velocity as
it pulls it inward), but the pulse then moves on to the next location in space
and does the same thing to the inherent motion located there. At each moment
at any point in space, the inherent motion itself that arrives from farther
out (because of the last pulse) is subject to the next pulse of gravitation,
and so the inherent motion itself is accelerated inward, giving it a higher
inbound velocity as it moves closer to the gravitating body. The gravitational
field is, therefore, like a flow of gravitational pulses outward in the inherent
motion everywhere pulling the inherent motion itself toward the gravitating
body. Thus, it is a steady gravitational force field, which would affect objects
in the way Newton’s law predicts.
However, when a gravitating body is moving back and forth across
space (for example, when a pair of dense astronomical bodies are in orbit
around one another), the pulses of forces propagating outward from the gravitating
body come from different locations from one moment to the next, and thus,
there is a wavelike change in the acceleration of the inherent motion at a
distance. Thus, any material objects located there will feel a gravitational
force that is changing directions from moment to moment.
Since the gravitational wave can accelerate material objects,
it carries potential energy across space, and thus, it is a form of matter
(which we are calling “gravitational matter”). If the gravitational field
were imposed by a gravitating body at rest in space, the gravitational matter
constituting it would be counted as part of the total quantity of matter (mass
and energy) accumulated at its center (because the gravitational force is
accelerating the inherent motion toward itself). But the gravitational matter
making up waves is not counted in the rest masses of the gravitating bodies
generating it (because the gravitational force is not accelerating the inherent
motion toward itself. Thus, gravitating bodies lose energy as they exert gravitational
waves. (The astronomical bodies orbiting one another will slow down and eventually
fall into one another.)
Precession of the perihelion of Mercury. This explanation
of how the force of gravitation is exerted can explain the precession of the
perihelion of Mercury (or any planet around a star). The inherent motion itself
is accelerated by gravitation, and thus the force of gravitation that is felt
by any bit of matter depends on the acceleration of inherent motion in the
part of space where it is located at the time.
Since the sun is so much more massive than Mercury, we can treat
it as if it were at rest in space. Thus, although it is sending out pulses
of gravitation through the inherent motion that accelerate the inherent motion
it reaches towards itself, the gravitational field is basically spherical,
with the strength of the gravitational force falling off at the square of
the distance. This is the gravitational field through which Mercury moves.
Mercury is moving roughly perpendicular to the sun’s radial
force field, and if that were all that determined the gravitational force
that Mercury feels, Mercury would follow the pathway predicted by Newton’s
law of gravitation (because its being the result of a pulse of gravitation
propagating from the sun does not make any difference to the force that Mercury
feels).
Mercury is also, however, another gravitating body. It is sending
out pulses of gravitational attraction radically in the inherent motion, accelerating
the inherent motion itself towards itself. Insofar as its pulses are oriented
in the same direction as those propagating radially from the sun, this will
make no difference, because Mercury’s force will be acting on an inherent
motion that is everywhere being accelerated toward the sun. However, Mercury
will also be accelerating the inherent motion toward itself in directions
perpendicular to the sun’s radial forces. And since the sun’s radial pulses
of gravitational forces travel by way of the inherent motion, they follow
the path of light rays, and since Mercury will be bending light rays that
pass by it (just as the sun does; see Gravitational
bending of light rays), Mercury will be bending the sun’s pulses of
gravitational forces toward itself as they pass by.
The acceleration of the inherent motion toward Mercury changes the location of the sun’s gravitational forces, but not the direction in which those forces accelerate bits of matter. As radial forces, they are normally pointing at the sun. But consider what happens to the inherent motion ahead of Mercury as it moves perpendicular to those radial forces. As it accelerates the inherent motion toward itself, it shifts the location of the inherent motion itself (the bending of the light rays), and thus, the gravitational force that would be exerted in those parts of space are no longer directed at the sun, but are slightly offset. They point to a location relative to Mercury that the sun would otherwise have only later in its orbit. Thus, when Mercury coincides with the part of space in which the displaced inherent motion is located, the force of gravitation will not be in the direction of the sun, but slightly offset.
To be sure, there is a symmetry about the acceleration of the
inherent motion in front of Mercury and behind in its direction of motion.
After all, light rays are bent towards it as they pass either in front or
behind Mercury. But there is an asymmetry caused by Mercury’s motion. It is
moving toward the inherent motion accelerated towards it in front, and it
is moving away from the inherent motion accelerated towards it from behind.
Thus, Mercury is affected by the displaced gravitational forces ahead of it,
because it is moving into the parts of space where they are located. And it
is moving away from the parts of space where the displaced gravitational forces
behind it are located.
The net effect of the asymmetry caused by Mercury’s motion into
the inherent motion it has accelerated towards itself in front of it as it
moves is that its change of location relative to space amounts to a greater
change of location relative to the inherent motion. The gravitational pulses,
like light rays, are pulled closer together in front of it, so that its velocity
relative to space makes a greater change in the direction of the gravitational
force it feels than would otherwise be the case.
Since through its orbit, the direction of the sun’s force is
always displaced in the same direction (as if Mercury were farther along in
its orbit than it actually is), the sun’s gravitational force is always making
Mercury change direction faster than it would otherwise, and thus, the orbit
as a whole precesses around the sun in the same direction as Mercury itself.
The alteration in the direction of the effective gravitational
force of the sun on Mercury is the major factor accounting for the precession,
but there are two additional factors making it different from Newtonian expectations,
which are relatively minor.
First, the propagation of Mercury’s pulses of gravitational
attraction outward in the inherent motion is not quite at the velocity of
light, because its acceleration of the inherent motion has given it an inbound
velocity. In front of Mercury as it is moving though the inherent motion perpendicular
to the sun’s radial acceleration, Mercury’s outbound pulses of gravitation
have a velocity that is less than the velocity of light outside of gravitation
by the escape velocity at each point in its outbound propagation.
Second, since Mercury itself is a material object, its motion
relative to the inherent motion subjects it to Lorentz distortions, including
a relativistic mass increase. Thus, it takes a greater gravitational force
to change its direction.
Phenomena
in Strong Gravitational Fields. The acceleration of the inherent motion
in space is what replaces the curvature of spacetime in the spatiomaterialist
explanation of gravitation. But we have considered mainly phenomena involving
weak gravitational fields and velocities much slower than light, and its assumption
about the nature of the gravitational force also explains other new GTR phenomena
involving strong gravitational fields and high velocity.
In strong gravitational fields, for example, the velocity of
the inherent motion itself (the ether) relative to space can approach the
velocity of light mediated by the inherent motion, and thus, spatiomaterialism
implies that a time dilation will occur even in free falling clocks, if they
have a sufficient high velocity relative to the inherent motion in space.
Consider, for example, a free falling clock that is shot upwards
out of a gravitational field so that it rises and falls back. At the top of
its trajectory, the cock will be momentarily at rest relative to space, and
even though it is not being accelerated against the gravitational attraction,
it may be suffering a Lorentz time dilation. In this case, it would be caused
by its constant velocity relative to rest in the inherent motion, which is
rushing inward because of its acceleration by the gravitating body.
This Lorentz time dilation is different from the gravitational
time dilation discussed above, which is caused by being accelerated in a gravitational
field. But both factors may be contributing to the red shift that observers
outside the gravitational field observe in light signals sent outward by such
objects.[5]
But since the Lorentz time dilation is a second order effect (a function of
v2/c2), while the
gravitational time dilation is a first order effect (a function of v/c), it doesn’t become significant until
the emitter’s velocity relative to the inherent motion approaches that of
light itself in the inherent motion. In strong fields, however, the Lorentz
time dilation may be a more significant cause of red shift than the gravitational
time dilation.
Indeed, material objects in strong gravitational fields with
very high velocities relative to the inherent motion will suffer all the Lorentz
distortions: length contraction, mass increase, and flattening of electric
force fields, as well as time dilation.
I have already mentioned that the acceleration of the inherent
motion can give the inherent motion itself (the ether) a velocity relative
to space that is as great as the velocity of light outside gravitation (that
is, in the ether). This is what happens at the Schwartzschild radius of a
black hole. No light can escape a black hole, because everywhere on that spherical
surface surrounding the black hole the outbound velocity of light mediated
by the inherent motion is canceled out by the inbound velocity of the inherent
motion itself. Any such photons would be at rest in space, even though they
are moving at the velocity of light in the inherent motion.
Nor could anything else escape the black hole, since doing so
would require moving through the inherent motion faster than the velocity
of light. That is why it is called an “event horizon”.
Free falling material objects cannot even be momentarily at
rest at the Schwartzschild radius, for the Lorentz distortions caused by their
velocity relative to the inherent motion at that point would require their
lengths to be zero, their physical processes to have stopped, and their masses
to be infinite.
Inside the event horizon, light traveling any direction in the
inherent motion would have an increasing velocity relative to absolute space
toward the center of the black hole. And any bits of matter being accelerated
by that acceleration of the inherent motion would move and interact with one
another as they do outside gravitational fields (except for tidal forces,
which bring their radial pathways closer together), as implied by Einstein’s
equivalence principle. But when the bits of matter reach the center of the
black hole, they must come to a stop. Physics does not say what happens then.
Material objects cannot withstand the forces on them at the center, and presumably,
they would collapse spatially, making the gravitational forces infinite. Thus,
the center of a black hole is aptly called a “singularity” in absolute space.
Since neither light nor gravitational pulses can propagate outbound
from beyond the Schwartzschild radius, the only indication of the amount of
matter that has fallen into the black hole is the size of the Schwartzschild
radius.
Spatiomaterialism can also explain what is happening around rotating
black holes. Rotating black holes are formed by matter spiraling in, and there
is an asymmetry about the gravitational field they set up which draws bits
of matter falling toward the back hole in the direction of its rotation.
The reason is that the force of gravitation exerted by matter
falling into a black hole propagates outward at the velocity of light in the
inherent motion, and since at the Schwartzschild radius, the inherent motion
itself is moving inward at the velocity light would have in the inherent motion
if it were outside gravitational influences, only the forces propagated outward
just before passing across the radius have an effect on the inherent motion
outside. And since the matter is spiraling past the Schwartzschild radius,
it has a greater effect behind than in front of its direction of motion. Thus,
other bits of matter in that region of space feel an attraction that is not
directly into the black hole, but which pulls it around the black hole in
the direction of the matter that preceded it.
[1]
The inherent motion in space is rather well represented by light cones in
the familiar diagrams. Each light cone represents the range of all possible
Lorentz equivalent inertial frames at its location, and the increased tipping
of light cones in the direction of the center of gravity at locations nearer
and nearer to that center represents the increasing velocity of the inherent
motion itself. The “event horizon” around a black hole is where they tip
so far that even the far side of the light cone is inclined toward the black
hole.
[2]
Compare this with the spacetime explanation of Will
(1986, pp. 69-74). Will traces the light ray’s path through spacetime by
considering the series of free falling frames through which it would pass.
He recognizes that the Newtonian-like half of the bending comes from a change
in the angle of the light passing through each frame due to the inward acceleration
as it passed through the previous frame. But in order to account for the
other half of the bending, he argues that there is a “curvature of space”
near gravitating bodies in which the number of measuring rods needed to
measure a line passing by the sun would be greater than expected by triangulating
the distance from outside the gravitational field. Though Will does not
explain why measuring rods would be shrunken, spatiomaterialism would agree
that free falling rods momentarily at rest relative to absolute space would
be contracted, because they would be suffering a Lorentz length contraction
due to their constant velocity relative to the ether (see page 203). But that length contraction is merely a symptom
of their velocity relative to the ether, and so the spatiomaterialist theory
explains the other half of the bending more directly. There is no need to
suppose that space itself is curved, only that the velocity of light in
space is altered.
[3]
This is a much simpler explanation than spacetime curvature affords. Compare
with Will
(1986, pp. 112-119).
[4]
Acceleration in rectilinear motion causes an apparent time dilation whose
rate continues to change as the velocity difference between the clocks continues
to increase. A constant rate of apparent time dilation caused by the Doppler
effect can occur outside gravitation only when the two clocks are located
at the center and rim, respectively, of a rotating disk and the acceleration
of the rim clock space always results in the two clocks having the same
relative velocity in the direction of the signals between them.
[5]
Though the two kinds of time dilation both involve the acceleration of the
inherent motion due that constitutes the force of gravity, they combine
mathematically the same way as the Doppler effect and Lorentz time dilation
due to motion outside gravitation, or the so-called “relativistic Doppler
effect”.