The Mass of Nows:
A Temporal Foundation for Inertia and Gravity

Joseph Wouk
January 6, 2026

Checked by Ara (Grok 4, xAI)

For a century, physics has lived with a quiet asymmetry. Special relativity shattered absolute simultaneity, forcing us to accept that "now" is observer-dependent—an infinite stack of "now-slices" foliating the four-dimensional block universe.

Yet when we turned to dynamics, to the origin of mass and force, we continued to treat space and time as a smooth, empty stage on which particles play. Inertia and gravity were described with exquisite mathematics, but their common cause remained mysterious. The equivalence principle told us they feel the same, but never why they are the same.

The Mass of Nows proposes a simple, radical answer: the stage is not empty. Between the infinite now-slices lies a dense plenum—the zero-point fields of every possible now, permeated by the four-dimensional extent of every particle's wave function.

Mass is not a property particles possess; it is the resistance they encounter when forced to cut through this plenum at the rate of 10⁴³ nows per second of proper time.
What follows is a complete, self-contained presentation of the theory in its current form, built on nine postulates grouped in three triads.
First Triad: The Ontology of the Block Universe
The relativity of simultaneity requires there exist an infinite number of “now slices” through all four dimensions of spacetime.
Special relativity implies the block universe: all events coexist eternally, but different observers slice the block at different angles. There is no privileged global "now," only an infinite foliation of simultaneous hypersurfaces.
All particles must exist in all “now slices” through spacetime. They do so by way of their wave function, which permeates all four dimensions of spacetime, and through quantum indeterminacy.
The quantum wave function is not a mere probability amplitude confined to one slice; it is the literal four-dimensional object that guarantees the particle's presence across the entire stack. Quantum indeterminacy ensures this presence is distributed rather than localized to a single worldline until measurement intersects a particular slice.
These four-dimensional waves, when viewed from the three-dimensional perspective of a single “now slice,” take on the form of a particle.
Wave-particle duality is not a paradox but a consequence of dimensionality: the 4D object intersects the 3D slice as a point-like particle with mass, charge, and spin.
Second Triad: The Origin of Inertial Mass
Acceleration causes the mass being accelerated to alter its “now slice.”
Changing velocity tilts the observer's foliation. To accelerate is to forcibly shift from one stack of now-slices to an adjacent, previously untouched stack.
While accelerating, the “now slice” becomes curved, causing it to pass through 10⁴³ “nows” per second of time change.
The curvature of the slice during acceleration sweeps it through fresh layers of the plenum at the Planck-scale density rate—roughly one new now per Planck time for every Planck volume traversed.
Passage through the zero-point energy (ZPE) of each “now” is what causes inertial mass. It is the “echo particles” that are pushed from one now to the next that causes resistance, however minimal. The pioneer anomaly illustrates this. It takes the solar system length of passage through one now slice which is an inertial reference frame before it gets noticed. Inertia is drag: the cumulative resistance from colliding with the undisturbed quantum vacuum states of all these newly encountered nows. The magnitude matches observation because the density of the plenum is fixed by Planck-scale physics.
Third Triad: The Origin of Gravitational Mass
All mass moves through the four dimensions of spacetime at the speed of light.
Timelike worldlines have constant proper speed c; rest mass is simply the degree to which motion is directed through the time axis rather than space.
Operation of Newton’s third law causes a warping of spacetime in reaction to the mass’ passage.
As a massive object threads the block, the fabric reacts (equal and opposite) by curving—concentrating the density of now-slices radially around the worldline.
This warping of spacetime causes mass passing through it to pass through 10⁴³ “nows” per second of time change—aka “gravity.”
Free-falling objects follow geodesics through this denser stack of nows, encountering the same 10⁴³-fold plenum resistance per second as an accelerating object in flat space. Inertial and gravitational mass are not merely equivalent; they are identical—both are now-drag, differing only in geometry (lateral shear vs. radial compression).
Consequences and Resolutions
This picture resolves longstanding puzzles with minimal addition—just the refusal to treat the block universe as ontologically empty between slices.
Equivalence principle: explained as identity, not coincidence.
Wave-particle duality: geometric (4D extent vs. 3D intersection).
Arrow of time: The speed of light always equals speed through space plus speed through time. Reversing the arrow would force the speed through space to exceed the speed of light which is not possible.
Cosmic inflation: the early universe expanded rapidly because the plenum of nows had not yet fully nucleated; insufficient drag allowed near-exponential growth until the quantum fields populated the slices evenly.
Black holes and the Big Bang: singularities are regions where now-density becomes infinite, halting forward motion through new nows—time "stops" because no fresh slices remain to enter.

The theory adds no new particles i.e. gravitons, no extra dimensions, no free parameters beyond those already fixed by Planck scale and c. It simply takes the block universe and quantum nonlocality seriously.

We have described curvature correctly (Einstein) and probability correctly (Bohr), but never the mechanism that makes motion costly. That mechanism is the”mass of nows” itself.
The stack is dense, patient, and waiting.