Sonny presented at the Icarus Interstellar “Starship Congress 2013” in Texas. His talk starts at 13:20 and ends 58:00 at Icarus Interstellar’s YouTube video of the event: **Day Three of Starship Congress 2013**. Note the interesting discussion of Q-Thrusters for interstellar missions (30 years to Alpha Centauri) and the “warp-drive” illustrations.

Sonny’s discussion of Metric Engineering began with a 2003 paper on the implications of the Alcubierre Metric, here in abstract: **A Discussion of Space-Time Metric Engineering**. A search on Google will find it at the publisher’s web-site for about $40 US, but a reformatted reprint (White 2003) might be found.

A citation search of the above paper presents two interesting derivative papers:

**Artificial gravity field** Which is a discussion of how one might use Metric Engineering to generate SF-style artificial gravity. Not easy, but intriguing nonetheless.

**Conformal Gravity and the Alcubierre Warp Drive Metric** explores an alternative formulation of gravity’s implications for the Alcubierre Metric and the feasibility of warp-drive. Conformal gravity offers the tantalising possibility of warp-drive without the need for NET amounts of negative energy/pressure.

Harold also collaborated with Eric Davis, an exotic propulsion Guru, to discuss the Higher-Dimensional version of the Alcubierre Metric: **The Alcubierre Warp Drive in Higher Dimensional Spacetime**. The work Harold did for this paper fed into the more recent series of papers on optimising the Warp-Drive’s properties to minimise the energy required. See the previous Crowlspace blog-post for details.

Wikipedia covers the Interferometer Test for space warps in the lab here: White–Juday warp-field interferometer. Present status of the experiment is encouraging, but not conclusive. Sources of noise need to be pinned down and minimised or analysed and removed via post-data analysis.

Recently (last month, almost in time for Christmas) this intriguing paper discussing Sonny’s 2003 paper appeared: **The Alcubierre Warp Drive using Lorentz Boosts according to the Harold White Spacetime Metric potential ?**. Fernando Loup and Daniel Rocha are warp-drive enthusiasts, not mainstream Relativists, but have produced interesting bodies of work over time. Best read critically.

Finally I should mention the EMDrive controversy and its possible relevance to the Q-Thruster. A patent lawyer, Robert Shawyer, has developed and promoted a propellantless drive based on the behaviour of microwaves in a convergent reflective cavity. He believes it provides thrust without propellant being expelled – its claimed thrust level is much too high for it to be a radio “photon-rocket” (unlike some supposedly propellantless drives that have appeared over the years). Shawyer has claimed interest and experimental validation from Chinese researchers, even though many mainstream physicists (including Greg Egan, the Australian SF writer who is a mathematician by training) have computed the relevant fields of the microwave cavity to demonstrate NO net thrust.

However, there may be a theoretical “out”, which might apply further to other proposed Thrusters. Fernando Minotti discusses one version of gravitation theory in which such thrusts might be produced: **Scalar-tensor theories and asymmetric resonant cavities**. While the EMDrive probably doesn’t work, another Thruster concept, developed by Cannae, might. Unfortunately their web-site is down so I can’t direct you to their rather interesting material. Whether it’ll produce real results in proper testing conditions *might* come from work at Sonny’s Eagleworks Lab.