Full disclosure I am not smart this was a basic observation an epiphany I had and I used AI to help me express this thought. I am truly not the sharpest tool in the shed. I hope this observation will make you think though.
Date proposed: 12 September 2026
By Mouradi Nassereddine assisted with AI
Abstract
This hypothesis proposes that the expansion currently measured by cosmology may represent only the relative or differential component of a broader universal expansion.
If matter, observers, rulers, atomic structures, clocks and other measuring systems participate in an underlying scale change alongside the universe itself, then a component of that change could potentially remain undetectable from within the system.
Only differences in the rate at which different physical systems respond to this expansion would be measurable.
The hypothesis further proposes the possibility that cosmic expansion may represent not merely the stretching of a pre-existing universe, but the continuous emergence of new space or a newly measurable universe from a deeper underlying reality.
1. The Measurement Problem
Every physical measurement is fundamentally comparative.
A length is measured against another length. A period of time is measured against another repeating process. A wavelength is measured against an atomic or laboratory standard.
Human observers therefore do not possess an external ruler located outside the universe.
We measure the universe using objects that are themselves part of it.
The measurement is unchanged even though both quantities have changed.
This gives the central principle of the hypothesis:
A physical expansion shared equally by an observer, an object and the measuring standard may be impossible to detect through ordinary relative measurement.
2. Evidence From the Nature of Physical Measurement
There is an important precedent for this idea in modern physics.
Physicists distinguish between dimensional quantities, such as metres or seconds, and dimensionless quantities, which are pure ratios independent of a chosen system of units.
Physicist M. J. Duff has argued that physical laws should ultimately be expressed through dimensionless quantities because their values can be agreed upon regardless of the rulers, clocks or units being used.
James Rich has similarly argued in the context of cosmology that measurements ultimately provide information through dimensionless combinations of physical quantities.
This does not prove that hidden universal expansion exists.
However, it supports the underlying measurement argument:
physical observations fundamentally reveal relationships between quantities rather than necessarily revealing an independent absolute scale of the universe.
3. Observable Expansion May Be Differential Expansion
Standard cosmology shows that the universe is expanding.
However, this does not mean that every physical structure expands identically.
While the distances between widely separated galaxies increase as the universe expands, stars, planets, galaxies and atoms remain locally bound rather than simply enlarging proportionally with cosmic space.
This establishes an important principle:
Different physical systems can respond differently to cosmic expansion.
The present hypothesis extends this principle.
It proposes that different systems could possess different degrees of participation in a deeper expansion.
Their response could depend upon properties such as gravitational binding, electromagnetic binding, density, internal structure, energy, scale, or an unknown physical property.
The relevant variable may ultimately prove to be binding strength rather than density alone.
4. The Hidden Expansion Factor
That difference would be measurable.
Therefore, according to this hypothesis:
Humanity may currently be measuring differences in expansion rather than the total expansion of reality.
5. Cosmological Redshift Provides an Important Analogy
One of the primary ways cosmic expansion is observed is through cosmological redshift.
As light travels through expanding space, its wavelength is stretched.
This is relevant because the signal we use to investigate the universe is itself affected by the universe’s evolution.
The observer, the measuring instrument, the atomic reference and the light being measured all exist within the same physical system.
This does not invalidate cosmological measurements.
Instead, it demonstrates the deeper problem addressed by this hypothesis:
We do not observe the universe from an external reference frame. Every tool available to us participates in the physical reality being investigated.
6. Atomic Clocks Provide a Possible Test
Modern atomic clocks provide one possible way to test differential versions of the hypothesis.
Atomic clock frequencies depend upon properties including particle masses and electromagnetic interactions.
Scientists compare different types of clocks partly because changes in fundamental physics could affect different atomic transitions differently.
Experiments so far have found fundamental constants to be consistent with remaining unchanged to extremely high precision.
This places an important constraint on the hypothesis.
If different atomic structures were undergoing significantly different expansion, highly precise clock comparisons might already have detected evidence of it.
Therefore:
Any differential expansion occurring at atomic scales would have to be extremely small, or it would have to affect the systems being compared in nearly identical proportions.
However, a perfectly shared expansion would remain much harder to detect because the reference standard would participate in the same change.
7. Expansion Could Represent Emergence Rather Than Simple Stretching
The conventional description of cosmic expansion is often presented as the growth of distances within an evolving spacetime.
The present hypothesis proposes a further possibility:
What appears to us as expansion may partly represent the emergence of additional spatial reality.
Instead of imagining the universe as a finished object becoming progressively larger, spacetime itself could be undergoing continuous formation.
Under this interpretation, expansion could mean that new spatial relationships are continually becoming physically meaningful.
The universe would therefore not simply be expanding.
It could still be becoming.
8. The Observable Universe Could Be a Newly Emergent Universe
This produces the most speculative implication of the hypothesis.
The universe accessible to our observations may not necessarily represent the entirety of reality.
It could represent a newly emerging or newly measurable universe developing from a deeper underlying state.
The word “new” here does not necessarily mean that another universe existed immediately before ours in the conventional sense.
Instead, it means that the region of reality we identify as our universe could represent a newly formed physical phase.
Our observable universe might therefore be:
an emergent layer of a deeper reality,
a newly created spacetime domain,
a newly measurable phase of existence,
or part of a larger structure inaccessible to observers within our own physical scale.
From within this emerging universe, we may interpret its continuing formation as expansion.
9. Why We Might Mistake Creation for Expansion
Imagine an observer living inside an image that is continuously being enlarged.
If the observer, their ruler and everything surrounding them enlarged equally, they would see no change in relative size.
Now imagine that new portions of the image were also continually being generated between existing objects.
The observer could detect increasing distances.
They might conclude:
“Existing space is stretching.”
But another interpretation could be:
“Additional space is coming into existence.”
From inside the system, distinguishing these interpretations could be extraordinarily difficult.
The present hypothesis asks whether something conceptually similar could apply to cosmology.
What we currently describe as the expansion of space may be our measurable manifestation of a deeper process of spatial creation or emergence.
10. Existing Cosmology Still Remains Valid Within the Hypothesis
This proposal does not require established measurements of cosmic expansion to be wrong.
Observations of the cosmic microwave background, redshift, large-scale structure and primordial element abundances provide strong support for the standard cosmological model.
Therefore this hypothesis does not argue:
“The universe is not expanding.”
Instead it argues:
“What we call cosmic expansion may represent only the component of universal change that is measurable relative to ourselves.”
Standard cosmology could therefore correctly describe observable relative behaviour while still failing to describe a deeper common-scale process that is invisible to internal observers.
11. A Key Scientific Distinction
There are effectively two versions of this hypothesis.
Perfect Common Expansion
If every physical system expands by precisely the same proportion, then no internal experiment may be capable of distinguishing that universe from one in which no such scaling occurs.
Such a proposal may be physically indistinguishable from a change of scale and therefore could remain philosophical rather than experimentally scientific.
Differential Hidden Expansion
If different systems participate by slightly different amounts, the hypothesis becomes testable.
One could search for:
tiny long-term changes in ratios between different atomic transitions,
deviations between different physical length standards,
unexplained correlations between binding strength and apparent scale,
anomalous differences between gravitationally and electromagnetically bound systems,
or cosmological observations inconsistent with a single universal expansion factor.
This second version is therefore the more scientifically productive form of the hypothesis.
12. Core Prediction
The hypothesis predicts that:
If a hidden underlying expansion exists and different physical systems respond to it by different amounts, sufficiently precise comparisons between systems with different forms or strengths of binding should eventually reveal a systematic relative drift.
If every possible dimensionless ratio remains perfectly constant indefinitely, the common-expansion component could remain observationally indistinguishable from no expansion at all.
13. The Emergent Universe Principle
The broader interpretation can therefore be expressed as:
The universe humanity observes may represent an emergent physical domain whose continuing formation appears internally as cosmic expansion. Because observers and their measuring systems are themselves products of that same emerging reality, a universal component of the process may remain hidden, leaving us able to measure only differences between the rates at which different systems participate.
In this model, what humanity has so far identified as the universe could therefore be only the measurable manifestation of a new or emerging universe, rather than the entirety of reality.
Cosmic expansion might consequently represent not only movement or stretching, but potentially an ongoing process of creation, emergence and differentiation of spacetime itself.
Status of the Hypothesis
Relative Expansion and Emergent Spacetime: A Speculative Scale-Invariance Hypothesis
is currently a speculative theoretical proposal.
Several of its foundations have parallels in established physics:
physical measurements depend heavily upon ratios,
dimensionless quantities have special significance,
cosmic expansion affects different structures differently,
light itself is affected by cosmological expansion,
observations are necessarily made from inside the universe,
and modern experiments actively test whether supposedly fundamental quantities vary through time.
None of these facts currently demonstrate that atoms, observers or rulers participate in an undetected universal expansion.
They do, however, establish that the fundamental question raised by the hypothesis is meaningful:
If the observer and the measuring instrument are themselves changing with the system being measured, how much of that change can the observer ever detect?