Clocks measure proper time
. There are two options of how we can conceive of
: either as the invariant evolution parameter or else as the time coordinate of spacetime. In special relativity (SR) [
1] and general relativity (GR) [
2],
can be used to parameterize worldlines in spacetime. In Euclidean relativity (ER),
is the time coordinate of spacetime, whereas cosmic time
(ticking uniformly since the Big Bang) is the parameter.
A new theory of spacetime must either refute SR/GR or else not conflict with SR/GR. Because of the different concepts, there is no conflict. However, ER tells us that the scope of SR/GR is limited: We must apply ER (a) to the very early universe, (b) to very distant objects (high-redshift supernovae), and (c) to entangled objects (that move in opposite 4D directions at the speed of light ). In such extreme situations, a 4D vector “flow of proper time” must be taken into account. Does ER make quantitative predictions? ER predicts the 10 percent discrepancy in the published values of the Hubble constant. What is the key message of ER? Physicists should strive for an all-natural description of nature.
Request to all readers: Avoid the following pitfalls. Several reviewers at top journals have fallen into them. (1) Do not apply the concepts of SR/GR to ER. The only standards for a new theory are its own concepts and measurement data. (2) Note that my formulation of ER is unique in its definition of concepts. is neither equal to coordinate time nor equal to . (3) Note that I do not refute SR/GR. I show that the scope of SR/GR is limited. (4) Note that ER reduces to SR, but not vice versa. This is because natural is more general than man-made . (5) Note that new coordinates can provide new insights. In SR/GR, coordinates are only labels that can be freely adjusted to simplify computations. In ER, coordinates are inherent properties of objects that cannot be adjusted because they refer to absolute 4D Euclidean space. (6) Note that a paper cannot cover all of physics. New concepts deserve to be published if they are helpful and consistent! Time will tell whether ER will replace SR/GR.
1. Introduction
Today’s concepts of space and time were coined by Albert Einstein. In SR, space and time are merged into a flat spacetime described by the Minkowski metric. SR is often presented in Minkowski space time [
3]. The lifetime of muons [
4] is one example that supports SR. In GR, a curved spacetime is described by the Einstein tensor. The deflection of starlight [
5] and the accuracy of GPS [
6] are two examples that support GR. Quantum field theory [
7] unifies classical field theory, SR, and quantum mechanics (QM), but not GR.
In 1969, Newburgh and Phipps [
8] pioneered ER. Montanus [
9] added a constraint: A pure time interval must be a pure time interval for all observers. According to Montanus [
10], this constraint is required to avoid “distant collisions” (without physical contact) and a “character paradox” (confusion of photons, particles, antiparticles). I show that the constraint is not required. There are no “distant collisions” if we take projections into account. There is no “character paradox” if we take the 4D vector “flow of proper time” of ER into account. Montanus used a Euclidean metric to calculate the deflection of starlight and the precession of Mercury’s perihelion [
10,
11], but failed to derive Maxwell’s equations [
10]. His constraint deprives ER of its most important feature: the full symmetry in all four axes. Montanus’ parameter is coordinate time. The correct parameter is cosmic time.
Almeida [
12] studied geodesics in 4D Euclidean space. Gersten [
13] showed that the Lorentz transformation is an SO(4) rotation in a mixed space
, where
is the Lorentz transform of
. There is also a website about ER:
https://euclideanrelativity.com. In other formulations of ER, coordinate time
of SR is merely swapped with proper time
of SR. Here we present a novel formulation of ER that takes three steps to make ER work: (1) The invariant evolution parameter is
(Hubble parameter
). (2) The time coordinate is proper time
. (3) Each object experiences two orthogonal projections from absolute 4D Euclidean space as a relative Euclidean spacetime.
Most physicists still reject ER because dark energy and non-locality make today’s cosmology and QM work, the SO(4) symmetry in ER seems to exclude waves, and there seem to be paradoxes in ER. And yet, I suspect that the real reason for rejecting ER is that physicists expect ER to describe events. This paper marks a turning point. I show: (1) Occam’s razor shaves off dark energy and non-locality. (2) SO(4) is compatible with waves. (3) Projections avoid paradoxes. (4) Spacetime in ER is not an event spacetime.
It is instructive to contrast Newton’s physics, Einstein’s physics, and ER. In Newton’s physics, all objects move through 3D Euclidean space as a function of independent time. There is no speed limit for matter. In Einstein’s physics, all objects move through a non-Euclidean spacetime. The 3D speed of matter is . In ER, all objects move through 4D Euclidean space. The 4D speed of everything is . For better readability, an observer is referred to as “he”. To compensate, Mother Nature is referred to as “she”.
2. Identifying an Issue in Special and General Relativity
In § 1 of SR [
1], Einstein considers a reference frame “in which the equations of Newton’s physics apply” (to a first approximation). If an object is at rest in this frame, its position in 3D space is determined using rigid rods and a 3D Euclidean geometry. If we also want to describe an object’s motion, we have to express its space coordinates as a function of time. Einstein points out the need to define time and gives an instruction on how to synchronize clocks at two points P and Q in 3D space. At a time
, a light signal is sent from P to Q. At
, the signal is reflected at Q. At
, it is back at P. The clocks synchronize if
In § 3 of SR, Einstein derives the Lorentz transformation. The coordinates
of an event in a system K are transformed to the coordinates
in K’ by
where K’ moves relative to K in
at the constant speed
and
is the Lorentz factor. Eqs. (2a–d) transform the coordinates from K to K’. There are covariant equations that transform the coordinates from K’ to K. The metric in SR is given by
where
is an infinitesimal distance in proper time
, whereas all
(
) and
are infinitesimal distances in coordinate space
and coordinate time
. Coordinate spacetime
is a construct because
is a
man-made concept: An observer’s proper time
is set equal to
. Thus, coordinate time is not inherent in all clocks. Clocks measure proper time
. Mathematically, SR is correct. Physically, there is an issue in SR and GR:
Einstein’s concepts of time fail to predict time’s arrow, the Hubble tension, and the baryon asymmetry; other observations (see Sect. 5) are predicted, but only by adding highly speculative concepts (cosmic inflation, expanding space, dark energy, non-locality). There are coordinate-free formulations of SR/GR [
14,
15,
16], but there is no absolute space and absolute time in these theories. SR/GR lack a “holistic approach” (definition: nature is considered an absolute manifold). Only a holistic approach provides Master Diagrams of nature (see Sect. 3).
The approach of SR/GR is “multi-egocentric” (definition: nature is considered a relative manifold). SR/GR have been very successful because they work well for all observers. What is not yet known: There is more than describing nature for all observers!
All observers’ perspectives taken together do not yield a holistic approach because they still lack absolute space and absolute time. Physics paid a high price for dismissing absolute space and absolute time: By reinstating both, ER predicts time’s arrow, the Hubble tension, and the baryon asymmetry; other observations are predicted
without adding highly speculative concepts. Thus, the issue is very real. The Michelson–Morley experiment [
17] refutes an “ether” (absolute 3D space), but not a 3D space with a relative angular orientation in absolute 4D space.
The issue in SR/GR is not about wrong predictions, but about fewer predictions and unnecessary concepts. It has much in common with the issue in geocentrism, which is the egocentric view of humanity. In the old days, it was tempting to believe that all celestial bodies would orbit Earth. Only astronomers wondered about the retrograde loops of some planets and claimed: Earth orbits the sun! Meanwhile, engineers have improved the accuracy of clocks. Nowadays, it is tempting to believe that accurate clocks of observers would be sufficient to measure the time elapsing for very distant or entangled objects. The human brain is smart, but it often considers itself the center/measure of everything.
The analogy of geocentrism to SR/GR is not perfect, but fits well: (1) After designating another planet as the center (or after a transformation in SR/GR), the view is still geocentric (or else egocentric). (2) Retrograde loops make geocentrism work, but are not required in heliocentrism. Dark energy and non-locality make today’s cosmology and QM work, but are not required in ER. (3) Heliocentrism places Earth on the same level as all other planets. ER places the observer on the same level as all other objects. (4) Heliocentrism overcomes the limitations of a geocentric approach. ER overcomes the limitations of a multi-egocentric approach. (5) Geocentrism was a dogma in the old days. SR/GR are dogmata nowadays. Have physicists not learned from history? Does history repeat itself?
3. The Physics of Euclidean Relativity
SR tells us that merging 3D Euclidean space and coordinate time into a Euclidean spacetime is problematic, especially when the rigid rods used by Einstein move at relativistic speeds. In this case, length contraction shortens them in the direction of motion. Einstein becomes aware of this problem and therefore merges 3D Euclidean space and coordinate time not into a Euclidean spacetime, but into a non-Euclidean spacetime. This step has far-reaching consequences because it also affects GR. We can avoid this unfortunate step by replacing the concepts of time. So, here is how we will proceed: To determine an object’s position in 3D space, we use the same 3D Euclidean geometry as Einstein in SR. However, instead of describing nature in man-made, coordinate time , we work directly with natural, proper time measured by clocks. That is, we do not construct time.
The postulates of ER: (1)
All objects move as “wavematters” through 4D Euclidean space (ES) at the speed of light . Wavematters (see Sect. 5.10) are a generalization of the de Broglie hypothesis. Louis de Broglie claimed that all matter also exhibits wave-like behavior [
18]. (2)
The laws of physics have the same form in the “realities” of objects that move uniformly through ES. An object’s reality is made up by its proper space and its proper time (two orthogonal projections from ES). My first postulate is stronger than the second postulate of SR: In ER, the speed
is both absolute and universal. My second postulate refers only to projections from ES, but not to ES itself. The metric in ER is given by
where
is an infinitesimal distance in the parameter
(to be given a meaning later on), whereas all
(
) are infinitesimal “pure distances” (neither spatial nor temporal) in ES. I prefer the indices 1–4 to 0–3 to emphasize the SO(4) symmetry. Each object is free to label the axes of its reference frame in ES. Observers are objects too. We consider two objects “r” and “b”. We assume: “r” (or “b”) labels the axis of its
current 4D motion as
(or else
) and the other three axes as
(or else
). According to my first postulate, “r” (or “b”) always moves in
(or else
) at the speed
. This axis is experienced as time because of length contraction at the speed
(see Sect. 4). If an object’s worldline is curved, its reference frame continuously adapts to the curvature.
In other words, each object experiences two orthogonal projections [
19,
20] from absolute ES as a relative Euclidean spacetime (EST): the axis of its current 4D motion as proper time
and the other three axes as proper space
. To determine an object’s position in 3D space (“proper space” and “3D space” are synonyms), we use the same 3D Euclidean geometry as in SR:
(
) of EST is equal to
of Minkowski spacetime. The time coordinate is different: In ER, an object’s
is the time coordinate of its reference frame. In particular,
is the length of a 4D Euclidean vector “flow of proper time”
.
where
is an object’s 4D Euclidean vector “proper velocity” in ES. The four components of
are called “proper speed”
(
). For comparison,
(
) are called “coordinate speed” in SR. Thus, Eq. (4) is my first postulate.
“Proper spacetime” is not a construct because is a natural concept: It is inherent in all objects. Internal clocks of all objects, such as biological clocks, measure the time coordinate of EST. No clock except an observer’s clock measures the time coordinate of Minkowski spacetime! and because both and are natural concepts. underlines that ER provides a unique description of nature even if ER and SR use the same . SR describes nature in man-made spacetime , where is man-made and is natural, but object-related. ER describes nature in natural spacetime , where is natural and is natural and universal. This is why I call it “cosmic time” and define it as (Hubble parameter ).
Five points are important: (1) Mathematically, ES is a 4D Euclidean manifold. (2) Physically, only three axes of ES are experienced as spatial and one as temporal. This is why ES as a whole cannot be observed. (3) Montanus [
9,
10,
11] did not distinguish between
and
. He merely swapped
with
in Eq. (3) to enforce a Euclidean metric. I show: In spite of
,
holds for uniformly moving objects. (4) Montanus also rejected four fully symmetric axes. I show: Whatever is proper time to me, it can be one axis of proper space—or a combination of space and time—for you. (5) Do not confuse ER with a Wick rotation [
21], which retains
as the invariant parameter. In ER,
and
.
It is instructive to contrast three concepts of time. Coordinate time is a subjective measure of time: An observer uses his clock as the master clock. Proper time is an objective measure of time: Clocks measure independently of observers. Cosmic time is an object’s total distance traveled in ES (length of its worldline) divided by . According to Eq. (4), we must add the distances traveled in all four axes to calculate the length of an object’s worldline. Since the invariant is universal, it represents absolute time. There is no twin paradox in ER: Each twin reads his own biological time as on his own clock. In Sect. 4, we discuss clocks that experience different gravitational fields.
We consider two identical clocks “r” (red clock) and “b” (blue clock). In SR, “r” moves in the axis. “b” starts at and moves at the constant speed . Fig. 1 left shows that instant when either clock moved 1.0 Ls (light seconds) in . “b” moved 0.8 Ls in . Thus, it displays “0.8”. In ER, both clocks move as “wavematters” (see Sect. 5.10) through ES. Fig. 1 right shows ES and two orthogonal projections. “r” moves in the axis. “b” starts at and moves at the constant speed . Fig. 1 right shows that instant when 1.0 s have elapsed in since “r” and “b” left the origin. “r” moved 1.0 Ls in . Thus, it displays “1.0” in the reality of “r”. “b” moved 0.8 Ls in and 1.0 Ls in . Thus, it displays “0.8” in the reality of “r” and “1.0” in the reality of “b” (not shown). Red digits on clock “b” indicate that “b” is read in the reality of “r”. Since one projection axis is time, the time displayed by a clock depends on the respective reality. Clock “r” remains at . Clock “b” remains at . Thus, according to Eqs. (4) and (5), and . In its reality, a uniformly moving clock always displays both its and .
Figure 1.
Minkowski diagram and ES diagram of two uniformly moving clocks. Left: “b” is slow with respect to “r” in . Coordinate time is relative (“b” is at different positions in and ). Right: “b” is slow with respect to “r” in . Cosmic time is absolute (“r” and “b” are at the same position in )
Figure 1.
Minkowski diagram and ES diagram of two uniformly moving clocks. Left: “b” is slow with respect to “r” in . Coordinate time is relative (“b” is at different positions in and ). Right: “b” is slow with respect to “r” in . Cosmic time is absolute (“r” and “b” are at the same position in )
We assume that observer R (or B) moves with clock “r” (or else “b”). In SR and only for R (because “b” measures and not !), B is at when R is at (see Fig. 1 left). Thus, “b” is slow with respect to “r” in . In ER and independently of observers, B is at when R is at (see Fig. 1 right). Thus, “b” is slow with respect to “r” in . In SR and ER, “b” is slow with respect to “r”, but time dilation occurs in different axes. Experiments do not reveal in which axis a clock is slow. Thus, both SR and ER describe time dilation correctly if they yield the same Lorentz factor, which will be shown in Sect. 4. If “b” reverses its motion in the axis at , it meets “r” again at . Now both clocks stand side by side in the proper space of “r” (not in the proper space of “b”!), and “r” displays “2.0” when “b” displays “1.6” (not shown).
ES is absolute. So, according to my definition in Sect. 2, the approach of ER is holistic. Why is it beneficial? R and B experience different axes as temporal. This is why Fig. 1 left works for R only. For B, a second Minkowski diagram is required, in which the two axes and are orthogonal. Here the approach is multi-egocentric. Most physicists do not care that two diagrams are required. They circumvent this problem by saying that simultaneity is not absolute. In ER, a Master Diagram of nature solves the problem: Fig. 1 right works for R and for B “at once” (at the same cosmic time ). Not only are and orthogonal, but also and . Here the approach is holistic. It turns out that Master Diagrams can be projected onto any object’s/observer’s reality. This is a huge benefit!
Regarding waves, I was misled by editors who claimed that the SO(4) symmetry of ES is incompatible with waves. SO(4) is compatible with waves that propagate and oscillate as a function of the parameter
. This is because Eq. (4) can be rewritten as
which is of the same form as Eq. (3), that is, as the metric of SR. From Eqs. (3), (4), (5), and
, we calculate
for uniformly moving objects. In this case,
in Eq. (8) can be replaced by
. Thus, ER reduces to SR for uniformly moving objects. I claim:
In ER, all objects are “wavematters” (natural concept of energy) that propagate through and oscillate in ES as a function of the parameter . In Sect. 5.10, I give evidence of my claim.
4. Geometric Effects in Euclidean Relativity
We consider two identical rockets “r” (red rocket) and “b” (blue rocket). Let observer R (or B) be in the rear end of “r” (or else “b”). The 3D space of R (or B) is spanned by (or else ). The proper time of R (or B) is (or else ). Both rockets start at the same point P and at the same time . They move relative to each other at the constant speed . The ES diagrams in Fig. 2 must satisfy my two postulates and the two initial conditions (same P, same ). This is achieved by rotating the red and blue frames against each other. In ES diagrams, objects retain proper length. For better readability, a rocket’s width is drawn in (or ) instead of and (or else and ).
Figure 2.
ES diagrams of two uniformly moving rockets. Observer R (or B) is in the rear end of “r” (or else “b”). Top left and top right: “r” and “b” move at the speed , but in different 4D directions. Their relative speed is . The ES diagrams are identical. Bottom left: In the projection onto the 3D space of R, “b” contracts to . Right: In the projection onto the 3D space of B, “r” contracts to
Figure 2.
ES diagrams of two uniformly moving rockets. Observer R (or B) is in the rear end of “r” (or else “b”). Top left and top right: “r” and “b” move at the speed , but in different 4D directions. Their relative speed is . The ES diagrams are identical. Bottom left: In the projection onto the 3D space of R, “b” contracts to . Right: In the projection onto the 3D space of B, “r” contracts to
Up next, we verify: Projecting distances in ES onto the axes
and
of an observer causes length contraction and time dilation. Let
(or
) be the length of rocket “b” for R (or else B). In a first step, we project
onto the
axis (see Fig. 2 left).
where
is the same Lorentz factor as in SR if and only if
. We recall from Sect. 3 that
(
). Thus,
and
are equal if and only if
. As already shown in Sect. 3,
for uniformly moving objects. Thus, ER confirms the Lorentz factor of SR. This is no surprise because we already know that ER reduces to SR for uniformly moving objects. In a second step, we project the distance that observer B moved in
onto the
axis (see Fig. 2 left).
where
(or
) is the distance that B moved in
(or else
). With
(R and B travel the same distance in ES, but in different 4D directions), we calculate
where
is the distance that R moved in
. Eqs. (10) and (13) tell us that ER confirms the relativistic effects of SR: length contraction and time dilation. We now ask: Which distances does R observe in the
axis? We rotate rocket “b” until it serves as a ruler in
. In the 3D space of R, this ruler contracts to zero length.
For R, the axis disappears because of length contraction at the speed . Our rockets serve only as an example. To calculate the lifetime of a muon in ER, we simply replace rocket “b” with a muon.
We now transform the proper coordinates of R (unprimed) to the ones of B (primed). R himself cannot measure the proper coordinates of B, and vice versa, but we can calculate them from ES diagrams. For instance, Fig. 2 right tells us how to calculate the 4D motion of R in the proper coordinates of B. The transformation, as calculated in Eqs. (14a–b), is a 4D rotation by the angle
. Note that adding rotations (in ER) does not violate Einstein’s relativistic addition of velocities (in SR) because EST is not equal to Minkowski spacetime. In SO(4), rotations are additive. In SO(1,3), velocities are not additive.
Up next, I show that ER also confirms gravitational time dilation. Initially, our clocks “r” and “b” are very far away from Earth (see Fig. 3 left). Eventually, “b” falls freely toward Earth. Clock “r” and Earth keep on moving in the axis at the speed .
Figure 3.
ES diagram and EST diagrams of two clocks. “b” accelerates toward Earth. Left: ES diagram and likewise EST diagram of “r”. The axis is drawn curved because it indicates the current 4D motion of “b”. Right: EST diagram of “b”. This is not (!) an ES diagram because “b” accelerates with respect to absolute ES. EST is relative (two diagrams). ES is absolute (one diagram for all)
Figure 3.
ES diagram and EST diagrams of two clocks. “b” accelerates toward Earth. Left: ES diagram and likewise EST diagram of “r”. The axis is drawn curved because it indicates the current 4D motion of “b”. Right: EST diagram of “b”. This is not (!) an ES diagram because “b” accelerates with respect to absolute ES. EST is relative (two diagrams). ES is absolute (one diagram for all)
Because of Eq. (7), all accelerations in ES are transversal. In particular, Eq. (7) tells us:
If an object accelerates in an observer’s proper space, it automatically decelerates in his proper time. The speed
of “b” in
increases at the expense of its speed
in
. We assume that
. In this case, the kinetic energy of “b” (mass
) in
is
where
is the gravitational constant,
is the mass of Earth, and
is the distance of “b” to the center of Earth in
. Eqs. (7) and (15) give us
With
(“b” moves in the
axis at the speed
) and
(“r” moves in the
axis at the speed
), we calculate
where
is the same dilation factor as in GR. We recall that we assumed
in Eq. (15). Thus, the very same argument applies as for the Lorentz factor:
if and only if
. Since spacetime in GR is locally Minkowskian, thus locally
(see the confirmation of the Lorentz factor in Sect. 4), we conclude: ER confirms—but only locally—the gravitational time dilation of GR. Thus, ER tells us that either GR or ER is an approximation. There is another big difference: In GR, gravity is the curvature of spacetime. In ER, gravity celebrates a comeback as a force. Because of Eq. (7), any acceleration rotates an object’s
and curves its worldline in ES. There is no action at a distance if field fluctuations propagate at the speed
. Newton’s law of gravity retains its
form because ES is projected onto (reduced to) 3D space.
In its reality, the uniformly moving clock “r” always displays both its
and
. “b” is slow with respect to “r” in
. Thus, “b” is slow even with respect to absolute time
. This is shown in Fig. 3 left, where “b” has not yet reached the green arc (
).
In its reality, an accelerated clock always displays its , but not . This is why two clocks placed next to each other display different times after being exposed to different gravitational fields. There are no devices that measure
under acceleration. I invite theorists to show: (1) Gravitational waves [
22] are predicted not only by GR, but also by ER. (2) Variational principles [
23] are another option to derive ER. Here I showed: ER confirms both
and
.
Résumé of time dilation: In SR, a uniformly moving clock “b” is slow with respect to a clock “r” at rest in the time axis of “b”.
In GR, an accelerated clock “b” or a clock “b” in a more curved spacetime is slow with respect to a clock “r” at rest in the time axis of “b”.
In ER, a clock “b”—uniformly moving or accelerated—is slow with respect to a uniformly moving clock “r” in the time axis of “r” (!). This is because the 4D vector
of “b” differs from
of “r”. ER confirms both
and
. Thus, the experiment by Hafele and Keating [
24] also supports ER. That is, GPS works in ER just as well as in SR/GR.
Fig. 4 illustrates how to read ES diagrams. Problem 1: Two objects move through ES. “r” moves in . “b” emits a radio signal at . The signal recedes radially from “b” in all axes as a function of , but cannot catch up with “r” in the axis. Can the signal and “r” collide in the 3D space of “r” if they do not collide in ES? Problem 2: A rocket moves along a guide wire. The wire moves in . The rocket’s speed in is less than . Doesn’t the wire eventually escape from the rocket? Problem 3: Earth orbits the sun. The sun moves in . Earth’s speed in is less than . Doesn’t the sun eventually escape from Earth?
Figure 4.
Three problems. Left: Two objects move through ES. The circle shows where a signal emitted by “b” at is when another 0.6 s have elapsed in . In ES, the signal and “r” do not collide. In the 3D space of “r”, they do. Center: In ES, the wire escapes from the rocket. In the 3D space of the wire, it does not. Right: In ES, the sun escapes from Earth. In the 3D space of the sun, it does not
Figure 4.
Three problems. Left: Two objects move through ES. The circle shows where a signal emitted by “b” at is when another 0.6 s have elapsed in . In ES, the signal and “r” do not collide. In the 3D space of “r”, they do. Center: In ES, the wire escapes from the rocket. In the 3D space of the wire, it does not. Right: In ES, the sun escapes from Earth. In the 3D space of the sun, it does not
The last paragraph seems to reveal paradoxes. The fallacy lies in assuming that all four axes of ES are experienced as spatial. Only three axes of ES are experienced as spatial and one as temporal. We solve all problems by projecting ES onto the 3D space of that object which moves in at the speed . In Fig. 4 left, the signal collides with “r” in the 3D space of “r” when their positions in coincide (as in SR, collisions do not require the same position in ). This happens when 1.6 s have elapsed in since “r” and “b” left the origin. The collision also occurs in the signal’s 3D space (not shown), where “r” reverses its motion at . Collisions in 3D space do not show up as collisions in ES because is not an axis in ES diagrams. ES diagrams do not show events, but the flow of proper time. In Fig. 4 right, the sun and Earth do not escape from each other spatially, but they age in different and changing 4D directions! This information is not available in SR/GR.
5. Experimental Evidence for Euclidean Relativity
In § 22 of GR [
2], Einstein mentions three tests for GR: gravitational redshift (see Sect. 5.2), deflection of starlight, and the precession of Mercury’s perihelion. Montanus [
10] showed that a Euclidean metric predicts the same deflection and precession as GR. He did not use
as the parameter, but
(page 13 of [
10]). Since spacetime in GR is locally Minkowskian, thus locally
(see Sect. 4), we conclude: For objects that stay together spatially on cosmological scales, such as the sun, Mercury, and Earth,
is as good a parameter as
. Thus, ER passes the latter two tests. On top, ER predicts the following observations.
5.1. Time’s Arrow
“Time’s arrow” stands for time that flows only forward. Why can’t it flow backward? (or ) is an object’s total distance traveled in ES (or else ) divided by . Regardless of its current direction of 4D motion, the “total distance traveled” can never decrease.
5.2. Gravitational Redshift
Gravitational redshift is the decrease in frequency of radiation emerging from a gravitational well. Frequency is related to time. Since ER locally confirms the gravitational time dilation of GR (see Sect. 4), ER locally predicts the same gravitational redshift as GR.
5.3. Cosmic Microwave Background (CMB)
In Sects. 5.3 to 5.9, I outline an ER-based model of cosmology, in which the Big Bang can be localized: It injected a huge amount of energy into ES at an origin O.
The Big Bang was a singularity in providing energy and momentum. Absolute, cosmic time
has been ticking uniformly since the Big Bang. Ever since the Big Bang (
), this energy has been moving through ES at the speed
. Shortly after
, energy was highly concentrated. While it receded from O, it became less concentrated and reduced to plasma particles in 3D space. Recombination radiation was emitted that we observe as CMB today [
25].
The ER-based model must be able to answer these questions: (1) Why is the CMB so isotropic? (2) Why is the CMB temperature so low? (3) Why do we still observe the CMB today? Some possible answers: (1) The CMB is scattered equally in the 3D space of Earth. (2) The plasma particles receded at a very high speed in (Doppler redshift, see Sect. 5.9). (3) Some of the recombination radiation hits Earth after having traveled the same distance in (multiple scattering) as Earth in .
5.4. Hubble–Lemaître Law
Earth and a galaxy G recede from the origin O of ES at the speed (see Fig. 5 left). G also recedes from Earth’s axis at the speed . Distance (or ) is the distance of G to Earth in the 3D space of Earth at the time (or else ). Because of the 4D Euclidean geometry, is to as is to the radius of an expanding 4D hypersphere. All injected energy is within this 4D hypersphere. Most energy is in its 3D hypersurface. An object can change its direction of 4D motion continuously because of a transversal acceleration (scattering, gravitational field) or discontinuously (photon emission, pair production).
Figure 5.
ER-based model of cosmology. The orange circles show where most of the energy emitted by G or S at the time is today at . The green arcs show parts of a 3D hypersurface. Left: G recedes from O at the speed and from the axis at the speed . Right: If happens to be at the same distance today at which the supernova of S occurred, recedes more slowly from than S
Figure 5.
ER-based model of cosmology. The orange circles show where most of the energy emitted by G or S at the time is today at . The green arcs show parts of a 3D hypersurface. Left: G recedes from O at the speed and from the axis at the speed . Right: If happens to be at the same distance today at which the supernova of S occurred, recedes more slowly from than S
where
is the Hubble parameter. If we observe G today at the cosmic time
, the recession speed
and
remain unchanged. Thus, Eq. (19) turns into
where
is the Hubble constant,
, and
is today’s radius of the 4D hypersphere. Eq. (20) is an improved Hubble–Lemaître law [
26,
27]. Cosmologists are well aware of
and
. They are not yet aware (a) that the 4D geometry is Euclidean, (b) that
is absolute, and (c) that Eq. (20) relates proper speed
to
from the present (not coordinate speed
to
from the past). Eq. (19) relates proper speed
to
from the past, but
is not a constant.
Of two galaxies, the one farther away recedes faster, but each galaxy maintains its recession speed. G moves in
at the speed
. Thus, it moves in
at the speed
. Thus, a clock in G is slow with respect to a clock on Earth in
by the factor
. The
values of Earth and
(energy emitted by G at the time
) never match.
Can and Earth collide in the 3D space of Earth if they do not collide in ES? As in Fig. 4 left, collisions in 3D space do not show up as collisions in ES.
collides with Earth when
has traveled the same distance in
as Earth in
.
5.5. Flat Universe
An object’s reality is made up by two orthogonal projections from ES. It experiences two seemingly independent structures: a flat “universe” (proper space) and proper time. This is true even if its worldline in ES is curved, as for clock “b” in Fig. 3 left.
5.6. Large-Scale Structures
Most cosmologists [
28,
29] believe that an inflation of space shortly after the Big Bang is responsible for the isotropic CMB, the flat universe, and large-scale structures. The latter are said to inflate from quantum fluctuations. I showed that ER predicts the isotropic CMB and the flat universe. ER also predicts large-scale structures if these quantum fluctuations expand together with the 3D hypersurface.
ER does not require cosmic inflation.
5.7. Cosmic Homogeneity (Horizon Problem)
How can the universe be so homogeneous if there are causally disconnected regions? In the Lambda-CDM model, region A at and region B at are causally disconnected unless we postulate cosmic inflation. Otherwise, an exchange of information would not have been possible. In the ER-based model, A is at (see Fig. 5 left) and B is at (not shown). A and B interpret (equal to their ) as their time axis. For A and for B, the axis disappears because of length contraction at the speed . From their perspective, A and B have never been separated spatially, but their proper time flows in opposite 4D directions. This is how A and B are causally connected. Their opposite 4D vectors do not affect causal connectivity as long as A and B stay together spatially.
5.8. Hubble Tension
Up next, I show that ER predicts the 10 percent discrepancy in the published values of
(known as the “Hubble tension”). We consider CMB measurements and distance ladder measurements. The values do not match:
according to team A [
30], and
according to team B [
31]. Team B made efforts to minimize the error margins in the distance measurements, but there is a systematic error in its calculation. The error stems from assuming a wrong cause of the redshifts.
We assume that team A’s value of is correct. We simulate the supernova of a star S that occurred at a distance of from Earth (see Fig. 5 right). The recession speed of S is calculated from the measured redshift. The redshift parameter tells us how each wavelength of the supernova’s light is either stretched by an “expanding space” (team B) or else Doppler-redshifted by receding objects (ER-based model). The supernova occurred at the time , but we observe it today at the time . While the supernova’s light moved the distance in , Earth moved the same distance , but in . This is because the light and Earth move at the same speed through ES.
According to Eq. (19), we now plot versus for distances from 0 Mpc to 500 Mpc in steps of 25 Mpc (red points in Fig. 6). The slope of a straight-line fit through the origin is roughly 10 percent higher than . This is because is not a constant. The red points tell us: If we compare the supernovae of two stars S and S’, the star farther away from Earth recedes at a higher speed. And yet, each star recedes uniformly on cosmological scales. As shown in Sect. 4, for uniformly moving objects. in our plot is thus equal to calculated from the measured redshift. According to Eq. (20), we must plot versus to get a straight line (blue points). Since team B does not take Eq. (20) into account, its value of is roughly 10 percent too high. Ignoring the 4D Euclidean geometry in the distance ladder measurements overestimates the value of . This explains the Hubble tension.
Figure 6.
Hubble diagram of simulated supernovae. The red points, calculated from Eq. (19), do not yield a straight line because is not proportional to , but to . The blue points, calculated from Eq. (20), yield a straight line because is proportional to
Figure 6.
Hubble diagram of simulated supernovae. The red points, calculated from Eq. (19), do not yield a straight line because is not proportional to , but to . The blue points, calculated from Eq. (20), yield a straight line because is proportional to
Eq. (20) requires the knowledge of , but measurable magnitudes of supernovae are related to . We solve this technical difficulty by rewriting Eq. (20) as
where
is the recession speed in
of a star
that happens to be at the same distance
today at which the supernova of S occurred (see Fig. 5 right). We calculate
By inserting Eqs. (19) and (21) into Eq. (22), we obtain
We kindly ask team B to recalculate its value of after converting all calculated to according to Eq. (23). Because of Eq. (21), team B then gets a straight line and the correct value of when plotting versus .
5.9. Cosmological Redshift
Fig. 6 also tells us:
The more high-redshift data are included in team B’s calculation, the more the Hubble tension increases. I now identify a second systematic error. This one is even more serious than the one in team B’s value of
. It concerns the supposedly “accelerating expansion of space” and cannot be resolved within the Lambda-CDM model unless we postulate dark energy. Most cosmologists [
32,
33] believe in an accelerating expansion because the recession speeds increasingly deviate from a straight line when plotted versus distance
. And indeed, an accelerating expansion of space would stretch each wavelength further, thus causing the deviations. In the Lambda-CDM model, the moment of the supernova is irrelevant. All that matters is the duration of the light’s journey to Earth.
In the ER-based model, all that matters is the moment of the supernova. Its light is redshifted by the Doppler effect. The longer ago a supernova occurred, the more
deviates from
, and thus the more
deviates from
. If a star
happens to be at the same distance of
today at which the supernova of S occurred, Eq. (23) tells us:
recedes more slowly (27,064 km/s, shortest arrow in Fig. 5 right) from
than S (29,750 km/s).
It does so because of the 4D Euclidean geometry. The 4D vector
of
deviates less from
of Earth than
of S deviates from
. Dark energy [
34] is held responsible for an accelerating expansion of space, but this is a stopgap solution for an effect that the Lambda-CDM model cannot explain. Supernovae occurring earlier in
recede faster because of a greater value of
in Eq. (19) and not because of a dark energy.
Cosmological redshift and the Hubble tension have the same physical background: In Eq. (20), we must not confuse with . Because of Eq. (19) and , is not proportional to , but to . This is why the red points in Fig. 6 deviate from a straight line. Any expansion of space—uniform or accelerating expansion—is only virtual even if the Nobel Prize in Physics 2011 was awarded “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae”. This particular prize was awarded for an illusion that stems from man-made, coordinate time. Most galaxies recede from Earth, but they do so uniformly in a non-expanding space. I can imagine that this insight will provoke controversy, but ER clearly identifies dark energy, the driving force behind a supposedly accelerating expansion, as an illusion. Space cannot expand. With respect to what could space expand? Energy recedes from the location of the Big Bang in ES. ER requires neither expanding space nor dark energy.
Cosmological redshift and the Hubble tension force us to consider the 4D Euclidean geometry, and the 4D vector
in particular. These two effects cast doubt on the Lambda-CDM model. GR works well as long as
is irrelevant, but
is relevant for high-redshift supernovae: Their 4D vector
deviates significantly from
of Earth. Space is not driven by dark energy. Galaxies are driven by their momentum, and they maintain their recession speed
with respect to Earth. Because of various effects (scattering, gravitational field, photon emission, pair production), the 4D motion of some energy deviates from receding radially from the origin O of ES. Gravitational attraction enables near-by galaxies to move toward our galaxy.
Table 1 compares two models of cosmology. Only the ER-based model does not require cosmic inflation, expanding space, and dark energy. Cosmology benefits greatly from ER. Up next, I show that QM also benefits greatly from ER.
Table 1.
Comparing two models of cosmology
Table 1.
Comparing two models of cosmology
5.10. Wave–Particle Duality
The wave–particle duality was first discussed by Niels Bohr and Werner Heisenberg [
35]. It has bothered physicists ever since. In some experiments, objects behave like waves. In others, the same objects behave like particles (known as the “wave–particle duality”). One object cannot be both because waves are distributed in space and capable of interference, whereas particles are localized in space and incapable of interference. To resolve the duality, we introduce a natural concept of energy:
All objects are wavematters that propagate through and oscillate in ES as a function of the parameter . In an observer’s reality, wavematters reduce to wave packets if not tracked or else to particles if tracked.
In Fig. 7, observer R moves in the
axis at the speed
. Three wavematters
,
, and
move in different 4D directions at the speed
. For better readability, a wavematter’s oscillation is drawn in the
plane, but it can oscillate in any axis that is orthogonal to its propagation axis.
does not move relative to R. It is automatically tracked and reduces to a particle (
). In the 3D space of R,
and
reduce to wave packets (
) if not tracked or else to particles (
) if tracked. In the 3D space of R,
moves at a speed less than
.
is what Louis de Broglie called “matter wave” [
18]. Schrödinger initially understood his wave equation as a description of matter waves [
36]. In the 3D space of R,
and
move at the speed
.
is the only wavematter that reduces to an electromagnetic wave packet (
) or else to a photon (
).
Figure 7.
Wavematters. Observer R moves in the axis. In his 3D space, and reduce to wave packets () if not tracked or else to particles () if tracked. : possibly an atom of R. : matter wave. : possibly a moving atom. : electromagnetic wave packet. : photon
Figure 7.
Wavematters. Observer R moves in the axis. In his 3D space, and reduce to wave packets () if not tracked or else to particles () if tracked. : possibly an atom of R. : matter wave. : possibly a moving atom. : electromagnetic wave packet. : photon
Remarks: (1) “Wavematter” is not just a new word for the duality. It is a new concept, which tells us where the duality comes from and that it is experienced by observers only. Isn’t it enriching to learn that particles, matter waves, photons, and electromagnetic waves all originate from a common concept? This is why I claim that all objects are wavematters. (2) In SR/GR, there is no perspective of a photon. Only in ER can we assign a proper space and a proper time to each object. A spatially distributed wave packet is projected onto 3D space and can reduce to a particle in that 3D space. (3) Energy and mass are equivalent [
37]. “Wavematter” stands for the equivalence of energy/wave and mass/particle.
In double-slit experiments, light creates an interference pattern on a screen if it is not tracked through which slit single portions of energy are passing. The same applies to material objects, such as electrons [
38].
Here light and matter behave like waves. The photoelectric effect releases an electron from a metal surface if the energy of an incident photon exceeds the binding energy of that electron. The interaction of photon and electron reveals their current position. Photon and electron are tracked.
Here light and matter behave like particles. Since an observer automatically tracks all objects that are slow in his 3D space, he classifies slow objects—and thus macroscopic objects—as matter. For better readability, some of my ES diagrams do not show wavematters, but how they appear to observers.
5.11. Quantum Entanglement
It was Erwin Schrödinger who coined the word “entanglement” in his comment [
39] on the Einstein–Podolsky–Rosen paradox [
40]. The three authors argued that QM would not provide a complete description of reality. Schrödinger’s neologism does not resolve the paradox, but it demonstrates our difficulties in comprehending QM. John Bell [
41] showed that QM is incompatible with local hidden-variable theories. Meanwhile, it has been confirmed in several experiments [
42,
43,
44] that entanglement violates locality in an observer’s 3D space. Entanglement has been interpreted as a non-local effect ever since.
Up next, I show that ER untangles entanglement without the concept of non-locality. There is no violation of locality in ES, where all four axes are fully symmetric. In Fig. 8, observer R moves in the axis at the speed . There are two pairs of wavematters. One pair was created at the point P and moves in opposite directions (equal to the axes of R) at the speed . The other pair was created at the point Q and moves in opposite directions at the speed . In the 3D space of R, one pair reduces to entangled photons. The other pair reduces to entangled material objects, such as electrons. R has no idea how entangled objects are able to “communicate” with each other in no time.
Figure 8.
Entanglement. Observer R moves in the axis. In the 3D space of R, one pair of wavematters reduces to entangled photons. The other pair reduces to entangled electrons. In the photons’ 3D space (or electrons’ 3D space, not shown), the photons (or else electrons) stay together
Figure 8.
Entanglement. Observer R moves in the axis. In the 3D space of R, one pair of wavematters reduces to entangled photons. The other pair reduces to entangled electrons. In the photons’ 3D space (or electrons’ 3D space, not shown), the photons (or else electrons) stay together
For the two photons (or the two electrons), the (or else ) axis disappears because of length contraction at the speed . Each pair stays together in its common proper 3D space. From their perspective, entangled objects have never been separated spatially, but their proper time flows in opposite 4D directions. This is how entangled objects are able to communicate with each other in no time. Their opposite 4D vectors do not affect local communication as long as the twins stay together spatially. There is a “spooky action at a distance” (a phrase attributed to Albert Einstein) for observers only.
Entanglement and the horizon problem have the same physical background: An observed object’s (or region’s) 4D vector
and its 3D space can differ from the observer’s 4D vector
and his 3D space. This is possible, but only in ES, where all four axes are fully symmetric. The SO(4) symmetry of ES predicts entanglement. It predicts the entanglement of photons just as well as the entanglement of material objects, such as atoms or electrons [
45]. Any measurement destroys the entanglement: It terminates the existence of one twin or tilts the axis of its 4D motion.
ER does not require non-locality.
5.12. Baryon Asymmetry
In the Lambda-CDM model, almost all matter was created shortly after , when the temperature was high enough to enable pair production. However, this process creates equal amounts of particles and antiparticles. The process of annihilation annihilates equal amounts of particles and antiparticles. Why do we observe more baryons than antibaryons (known as the “baryon asymmetry”)? From an observer’s perspective, wavematters reduce to wave packets or else to particles. Pair production creates particles and antiparticles that annihilate each other very soon. Thus, there is one source of long-lived particles (reduction of wavematters), one source of short-lived particles (pair production), but only one source of short-lived antiparticles (pair production). This explains the baryon asymmetry. Why don’t wavematters reduce to antiparticles? Obviously, this was not nature’s intention.
Note that an object moving in
is not necessarily an antiparticle. Its 4D vector
is reversed with respect to an observer’s
who moves in
, but its physical charges are not necessarily reversed. ER also tells us why an antiparticle’s proper time seems “to flow backward”: Proper time flows in opposite 4D directions for any two wavematters created in pair production. ER predicts that these two wavematters are entangled. This even gives us a chance to falsify ER. All scientific theories must be falsifiable [
46].
6. Conclusions
Today’s physics lacks two qualities of time: absolute and vectorial. (1) In ER, there is absolute time separating absolute past, present, and future. In SR/GR, there is no absolute time. (2) In ER, is the length of the 4D vector . In SR/GR, there is no 4D vector . Information hidden in and is not available in SR/GR. There are more differences: In SR, spatial and temporal distances are relative. In ER, the angular orientation of an object’s reference frame in ES is relative. Clock synchronization works in ER just as well as in SR, but replaces in Eq. (1). Regarding causality, a finite speed is incompatible with an absolute coordinate time, but compatible with an absolute parameter time.
ER reduces to SR and confirms—but only locally—the gravitational time dilation of GR. Thus, ER tells us that SR is exact, whereas either GR or ER is an approximation. GR is more likely that approximation because absolute suits QM better than relative . For instance, time itself is not an operator in the Schrödinger equation, but acts as an absolute, external parameter. Cosmic time is such a parameter. There is no such parameter in GR. I doubt that 12 predictions in different areas of physics (cosmology, QM, particle physics) are 12 coincidences. Some observations do not require ER, but highly speculative concepts (cosmic inflation, expanding space, dark energy, non-locality). None of these concepts is required in ER. Thus, Occam’s razor shaves them all off. No exceptions.
It was a wise decision to award Einstein the Nobel Prize for his theory of the photoelectric effect [
47] and not for SR/GR. ER penetrates to a deeper level. Einstein, one of the most brilliant physicists ever, did not realize that nature’s fundamental metric is Euclidean. Einstein sacrificed absolute space and absolute time. ER reinstates absolute space (not 3D space, but 4D space) and absolute time (not coordinate time, but parameter time), but ER sacrifices the absoluteness of particles, matter waves, photons, electromagnetic waves. In retrospect, man-made, coordinate time delayed the formulation of ER. For the first time ever, humanity understands the nature of time:
Cosmic time is an object’s total distance traveled in ES divided by the speed of light . The human brain is able to imagine that we all move at the speed
. With that said, conflicts of humanity become all so small.
Is ER a physical or a metaphysical theory? That is a very good question because only in proper coordinates can we access ES, but the proper time of another object is not measurable. And yet, this is a minor problem because we can calculate an object’s proper time from ES diagrams, as shown in Eq. (14b). The problem with coordinate time is persistent: is incompatible with Master Diagrams (ES diagrams). These diagrams display a mathematical reality beyond all observers’ realities. Measurements are equivalent to projecting ES onto an observer’s reality. The projections remind us of the collapse of wave functions in QM. Measurements are our preferred source of knowledge, but they require observers whose concepts may be inadequate. I am told that physics is all about observing. I disagree. Can we observe quarks? Unfortunately, physicists have applied —which works well in everyday life—to the very distant and very small. This is why cosmology and QM benefit most from ER. ER is a physical theory because it predicts what we observe.
It seems as if Plato had anticipated ER in his
Cave Allegory [
48]: Humanity experiences projections and cannot observe a reality beyond. I laid the groundwork for ER and showed how powerful it is. Paradoxes are only virtual. The key question in science is this: How do we describe nature without adding highly speculative concepts? The answer leads to the truth. The pillars of physics are ER, SR/GR for observers, and QM. Together, they describe nature from the very distant to the very small. Everyone is welcome to test the natural concepts of ER. For an experimental physicist like me, it makes perfect sense to work directly with natural, proper time measured by clocks.
Only in natural concepts does Mother Nature reveal her secrets. Isn’t it natural that she rewards an all-natural description?
Acknowledgements
I thank Siegfried W. Stein for his contributions to Sect. 5.8 and Figs. 2, 4, 5. After several unsuccessful submissions, he decided to withdraw his co-authorship. I thank Matthias Bartelmann, Walter Dehnen, Cornelis Dullemond, Xuan Phuc Nguyen, Dirk Rischke, Jürgen Struckmeier, Christopher Tyler, Götz Uhrig, and Andreas Wipf for asking inspiring questions about ER. My special thanks go to all reviewers and editors for investing some of their valuable, proper (!) time.
Comments
(1) Further studies on gravity are required, but this is no reason to reject ER. GR seems to explain gravity, but GR is incompatible with QM unless we add quantum gravity. Sects. 5.10 and 5.11 show that QM benefits from ER. (2) In ES, there are no singularities and thus no black holes. This, too, is no reason to reject ER. Singularities conflict with QM. In ER, black holes can be supermassive objects. (3) Solutions often pop up when the symmetry is taken into account. The symmetry of nature is SO(4). (4) Absolute time puts an end to all discussions about time travel. Does any other theory explain time’s arrow as beautifully as ER? (5) Physics does not ask: Why is reality a projection? Projections are far less speculative than cosmic inflation plus expanding space plus dark energy plus non-locality.
It takes open-minded editors and reviewers to evaluate a theory that heralds a paradigm shift. Taking SR and GR for granted paralyzes progress. I apologize for my numerous preprint versions, but I received little support only. The preprints document my path. The final version is all that is needed. I did not surrender when top journals rejected ER. Interestingly, I was never given any solid arguments that would disprove ER. Instead, I was advised to consult experts or to submit to a different journal. Were the editors afraid of publishing against the mainstream? Did they underestimate the benefits of ER? I was told that predicting 12 observations all at once were too many to be trustworthy. I disagree. Paradigm shifts often yield several insights. Even good friends refused to support me. Every setback motivated me to formulate ER even better. Finally, I identified an issue in SR and GR.
A well-known preprint archive suspended my submission privileges. I was penalized because I showed that GR is not as general as it seems. I was told that I may only submit articles that have already appeared in a mainstream conventional journal. The editor-in-chief of a top journal replied: “Publishing is for experts only.” One editor rejected ER because it would “demand too much” from his experts. Several journals rejected ER because it was “neither innovative nor significant”. I do not blame anyone. Paradigm shifts are hard to accept. In the long run, ER will prevail simply because it predicts what we observe. These comments shall encourage young physicists to stand up for promising ideas even if it is hard work to oppose the mainstream: “unscholarly research”, “fake science”, “too simple to be true”. Simplicity and truth are not mutually exclusive. Beauty is when they go hand in hand together.
Conflict of interest
The author has no conflicts to disclose.
Data availability
The data that support Euclidean relativity are available within the article.
Funding
No funds, grants, or other support was received.
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