The Spacetime Metric

Profile

Alexey Bobrick

Astrophysicist; Chief Science Officer at Applied Physics

Bobrick develops mathematical models of warp geometries and their matter requirements. With Gianni Martire, his 2021 paper describes a broader family of moving spacetime shells, including slower-than-light spherical models with positive energy. Their framework also makes clear that a moving shell still needs propulsion. These are calculated spacetime configurations, with energy requirements determined from the geometry.

Affiliations

  • Applied Physics, PBC

Channels

Bibliography

A bibliography listing does not establish authorship. Credits appear under attribution.

Published bibliography entries: 3. Showing 1–3 of 3.

  1. Listed work

    Paper · 2021

    Introducing physical warp drives

    1. Alexey Bobrick(Author)
    2. Gianni Martire(Author)

    Bobrick and Martire model warp spacetimes as moving shells surrounding a flat passenger region, rather than as self-propelling engines. Their 2021 paper develops spherical configurations with positive energy at speeds below light, allowing gravity outside the shell and slower clocks inside relative to distant observers moving with it. They also explore changes to shape, interior volume and clock rates in other geometries. Flattening an Alcubierre configuration reduces its calculated negative-energy requirement, but the superluminal examples still violate the averaged null energy condition, a restriction on energy along light rays. Even their extremely thin examples that meet selected quantum inequalities retain this problem. Changing a shell’s velocity requires propulsion; a stationary geometry alone supplies no acceleration mechanism.

  2. Listed work

    Paper · 2024

    Analyzing Warp Drive Spacetimes with Warp Factory

    1. Christopher Helmerich(Author)
    2. Jared Fuchs(Author)
    3. Alexey Bobrick(Author)
    4. Luke Sellers(Author)
    5. Brandon Melcher(Author)
    6. Gianni Martire(Author)

    Helmerich, Fuchs, Bobrick, Sellers, Melcher and Martire note that warp research has relied on analytic methods whose simple metric forms limit which solutions can be explored. They introduce Warp Factory, a numerical toolkit that examines general warp geometries by evaluating the Einstein field equations and computing the energy conditions. It also computes metric scalars and produces visualisations in 2D and 3D of metrics and their stress-energy tensors. Physicality checks have usually looked only at energy density seen by Eulerian observers, which is not enough for a full evaluation of the energy conditions. The toolkit lets researchers explore a wide range of warp metrics, especially where analytic work becomes impractical, and the paper applies it to commonly modelled metrics.

  3. Listed work

    Paper · 2024

    Constant Velocity Physical Warp Drive Solution

    1. Jared Fuchs(Author)
    2. Christopher Helmerich(Author)
    3. Alexey Bobrick(Author)
    4. Luke Sellers(Author)
    5. Brandon Melcher(Author)
    6. Gianni Martire(Author)

    Fuchs, Helmerich, Bobrick, Sellers, Melcher and Martire present a constant-velocity, slower-than-light warp drive solution that satisfies all of the energy conditions. It combines a stable shell of matter with a shift vector distribution closely matching well-known warp solutions such as the Alcubierre metric. The team generates the metric numerically, evaluates the energy conditions and confirms the shift cannot be removed by a change of coordinates. The result carries observers along geodesics, as the Alcubierre metric does, while satisfying the null, weak, dominant and strong energy conditions. Classic warp spacetimes can meet the energy conditions once a regular matter shell with positive ADM mass is added.