Glossary of Terms

Arrow of Time: The unidirectional nature of time — why we remember the past but not the future, why entropy increases, why causes precede effects. In PSK, the arrow of time is the direction of spatial densification. We traverse from sparser to denser density states; the reverse is impossible because sparser configurations no longer exist geometrically.

Block Universe: A concept from general relativity in which past, present, and future all exist equally — the universe is a static four-dimensional block. PSK rejects this: the past (sparser density states) no longer exists, and the future (denser states) has not yet emerged.

c (Speed of Light): In standard physics, the speed at which light propagates and the universal speed limit. In PSK, c is the rate of spatial densification — the fundamental constant from which all other physical constants derive.

Coalescence: One of two effects arising from spatial densification. As space densifies, matter experiences an inward pull toward regions of higher density — the density gradient or "wake" left by other matter. Coalescence is what we observe as gravitational attraction.

Contiguity: The geometric condition of being in direct contact with no void between. In PSK, all matter was contiguous in the infinite past when space was infinitely sparse. The critical density threshold marked when voids first emerged.

Critical Density Threshold (ρ_critical): The spatial density at which voids first emerged between previously-contiguous matter, approximately 4.6 billion years ago. Before this, all matter existed as contiguous plasma. After it, discrete atoms became possible.

Density Gradient: A region where spatial density varies with position. In PSK, matter creates density gradients (wakes) as it traverses densifying space. These gradients are what we experience as gravitational fields.

Densification: The core process in PSK: space becoming progressively denser everywhere, uniformly, at rate c. All physical phenomena — gravity, time, thermodynamics, quantum effects — are manifestations of this single process.

Divergence: One of two effects arising from spatial densification. As space densifies, metric expansion causes coordinate separation between points. Divergence is balanced by coalescence to maintain equilibrium.

Equilibrium (Geometric): The balance between coalescence and divergence that matter maintains as it traverses densifying space. This equilibrium gives rise to stable structures at all scales.

Euclidean Geometry: The geometry of flat space. PSK asserts that space is fundamentally Euclidean everywhere — flat, orthogonal, isotropic, homogeneous, infinite in extent.

Historical Density State: A particular spatial density corresponding to a specific moment in the continuous densification process. Because densification proceeds uniformly at rate c, each density state corresponds to a spatial density in the past. Matter that remains separated in the now remains coincident during the continuum of sparser historical density states where their coordinate volumes intersect. The concept of a future density state (denser than now) is equally valid, representing states the universe will evolve toward.

Hubble Radius: The distance at which Hubble recession velocity equals c — approximately 13.8 billion light-years. This is a spatial measure, not a temporal one. It should not be confused with the age of the universe.

Hubble Velocity: The recession velocity of distant matter due to metric expansion, proportional to distance. Unlike inertial velocity, Hubble velocity involves no acceleration and produces no time dilation.

Inertial Velocity: Velocity resulting from acceleration. Unlike Hubble velocity, inertial velocity involves displacement in the density field and produces time dilation.

Inverse Square Law: The principle that gravitational and electromagnetic effects diminish as 1/r² with distance. In PSK, this arises from the geometry of past contiguity and the spherical surface of intersection in past density states.

Metric Expansion: The increase in coordinate distance between points due to spatial densification. Not physical motion — matter does not move through space; rather, the metric (the measure of distance) increases.

Primordial Plasma: The state of matter before the critical density threshold: all matter contiguous, no voids, no discrete atoms. "Primordial" refers to configuration, not temporal origin.

Proper Volume: The intrinsic volume of matter, which remains constant as space densifies. Matter maintains proper volume through the equilibrium of coalescence and divergence.

Redshift: The shift of light toward longer wavelengths from distant sources. In PSK, redshift reflects the density differential between emission and observation states.

Spatial Density (ρ): A measure of how dense space itself is at a given location and time. In PSK, spatial density increases everywhere at rate c.

Spacetime: In general relativity, the unified four-dimensional manifold combining three spatial dimensions and one temporal dimension. PSK rejects this unification: space and time are ontologically distinct.

State-Mapping: PSK’s interpretation of light and electromagnetic phenomena. Rather than photons traveling through space, state-mapping is the causal connection between matter established through past contiguity.

State-Sharing: PSK’s interpretation of quantum measurement. When a detector interacts with a quantum system, it joins a state-sharing relationship — equilibrating to a shared configuration.

Time Dilation: The phenomenon whereby clocks in different conditions tick at different rates. In PSK, time dilation results from displacement in the density field — caused by acceleration or by being in a gravitational wake.

Wake: The density gradient left by matter as it traverses densifying space. Wakes are what we experience as gravitational fields. Steeper wakes (at smaller scales) produce what we call the strong nuclear force.

Weak Force: In PSK, not a force but geometric shedding — the process by which unstable configurations shed what does not fit the minimum-energy path through densification. Neutrinos are the residue of this shedding.