Toy Torsion Metric in QMU: Aether Tubes, Path Shortening, and Geodesics

What if the space between two distant locations could be threaded by a narrow Aether "tube" in which the local light cone opens and the effective distance shrinks, without invoking exotic matter or changing spacetime topology? This preprint develops a toy torsion metric in Quantum Measurement Units (QMU) that makes this question precise and embeds it in a fully ledger-first Aether framework. The Aether Physics Model (APM) treats space as a rotating electromagnetic Aether composed of discrete Aether units. The QMU system replaces SI/MKS with a ledger built from the electron mass mₑ, the Compton length λC, the quantum frequency Fq, and electrostatic and magnetic charge units. Within this framework, the paper introduces a one-dimensional "torsion tube" metric along a dimensionless coordinate x̂ = x / λC and dimensionless time t̂ = Fq t. The tube is characterized by a dimensionless torsion intensity Ξ, defined from a torsion loading factor and a twist number N that counts net Aether-frame rotations along the tube. For a uniform tube, the line element isdσ² = -\,dt̂² + 11+Ξ²\,dx̂²,which directly encodes the influence of Aether torsion on geodesics. The model shows that the proper separation between tube endpoints is shortened toDeff = D√1+Ξ²,so the path-shortening factor isf = DeffD = 1√1+Ξ².At full Aether loading, Ξ² scales approximately as N², so large twist numbers N give f ~ 1 / |N| while the torsion energy cost grows as N². This makes explicit the engineering tradeoff between aggressive path shortening and torsion energy investment. The paper derives the geodesic equations for this metric in QMU-normalized coordinates. For timelike geodesics with energy parameter E, the coordinate speed isv(x̂) = dx̂dt̂ = √1 - 1E²\,√1+Ξ²,and for null geodesics one finds|dx̂dt̂|ₙᵤₗₗ = √1+Ξ².In a spacetime diagram, the torsion tube appears as a region in which the null cone widens and both matter and radiation can traverse larger coordinate distances per unit t̂, even though they remain causal with respect to the modified metric. In the special case of constant Ξ, geodesics remain straight in the (t̂,x̂) plane, but the relation between coordinate distance, proper distance, and null slopes is deformed. A major goal of this work is to position the Aether torsion tube within the broader landscape of spacetime shortcut and torsion theories. The paper compares the QMU construction to: Traversable wormholes (Morris–Thorne, Visser) that shorten paths via nontrivial topology and typically require exotic stress-energy. Warp-drive metrics (Alcubierre, Natario and later refinements) that contract space in front of a bubble and expand it behind, often at the cost of violating energy conditions. Krasnikov tubes, where a prepared spacetime tube opens the light cone along a specific path to allow rapid return travel. Torsion-based gravity theories such as Einstein–Cartan and metric-affine gauge theory, in which torsion is tied to spin density and appears in the spacetime connection. Casimir and vacuum-energy supported wormholes, where structured quantum vacuum plays the role of exotic matter. Transformation-optics analogues in metamaterials, where effective optical metrics are designed via spatially varying permittivity and permeability. The Aether torsion tube is most closely analogous to a one-dimensional Krasnikov tube, but recast in a QMU Aether ledger. It differs from Einstein–Cartan torsion in that Ξ is not sourced by spin density; instead, Ξ is defined algebraically from Aether rotational and magnetic ledgers: the Aether unit Aᵤ, the curl scale, the maximum Aether mass mₐ, the maximum Aether magnetic charge eₐ², and the twist number N. The model does not postulate a stress-energy tensor; instead, it treats the torsion tube as a kinematic and metrological target. The question is not what stress-energy supports the metric, but whether the Aether can sustain torsion intensities Ξ and twist numbers N in a way that can be excited and measured in the laboratory. To make this testable, the paper includes an explicit Experimental Calibration Strategy appendix expressed entirely in QMU. It outlines: Curl metrology using magnetically ordered materials to constrain a universal curl scale. Calibration of the Aether unit Aᵤ via the QMU Ledger One identity Aᵤ · curl = Fq²λC². Determination of the maximum Aether magnetic charge eₐ² and torsion loading factor Ξload from Aᵤ, curl, mₐ, and Fq. Direct torsion tube experiments using phase-linked cavities, chronovibrational clock arrays, and interferometric probes in the small-Ξ regime. Construction of a design space in Ξload, N, and D̂ = D / λC that tells engineers where torsion grappler concepts might be feasible, excluded, or beyond reach. Overall, this preprint serves two purposes. First, it provides a self-contained derivation of a toy torsion metric in QMU, including geodesics, path shortening, null-cone widening, and torsion energy scaling. Second, it acts as a comparative review and unifying framework: wormholes, warp drives, Krasnikov tubes, torsion gravity, Casimir wormholes, and transformation-optics analogues are brought side-by-side and contrasted with the Aether torsion tube approach. The result is a consolidated reference for researchers and engineers who are exploring spacetime-shortcut technologies and want to understand what the Aether Physics Model and QMU have to offer as a metrological and design framework.