DIRD Traversable Wormholes, Stargates, and Negative Energy

From the source

1. The right way to study wormhole spacetimes is to decide beforehand on the geometry you want, use the Einstein field equation to calculate the distribution of matter required to set it up, and then assess whether that matter is physically reasonable — not to add matter and solve for the geometry.Section II, opening

2. Insert the spherically symmetric traversable-wormhole line element into the Einstein field equation and the source matter must have zero or negative energy density and/or an outward radial tension larger in magnitude than the energy density; a flat-faced throat — a stargate — is the special case where the two principal radii of curvature go to infinity, the surface energy density and surface tensions go to zero, and a traveller stepping through feels no tidal gravitational forces and sees no exotic matter threading the throat.Section II-A and II-B, Equations 1 through 4

3. The energy conditions are hypotheses rather than laws: quantum field theory has allowed states with local regions of negative energy density since 1965, generic spacetime geometries violate all of them, and Davis writes that every energy-condition hypothesis had been experimentally shown to be false in the laboratory 25 years before it was formulated. Violating the energy conditions commits no offense against nature.Section III, The General Relativistic Definition of Exotic Matter and the Energy Conditions

4. Negative energy is generated in the laboratory today by several routes: squeezed vacuum states of the electromagnetic field, whose energy density falls below zero once every cycle for every nonzero squeeze amplitude; the Casimir vacuum between conducting plates; gravitationally squeezed zero-point fluctuations near astronomical masses; and a mirror moving with increasing acceleration. Davis singles out the first simple, scalable squeezed-vacuum source — a continuous-wave diode laser and a rubidium vapour cell — as the point at which the experimental tools become available.Section III-B, items 1 through 6, Equation 5

5. The gross upper limit on what a wormhole costs is an equivalent mass of about minus 0.71 Jupiter masses per metre of throat, so a 1 metre throat needs about minus 0.71 Jupiter masses and a 1 km throat about minus 709.9; but that figure is only an upper bound. Visser and co-workers showed by a volume-integral quantifier that traversable wormholes exist which are supported by arbitrarily small quantities of negative energy, and that this is a general result — the violation can be made arbitrarily small, though not made to vanish entirely.Section IV-A and IV-B, Equations 9 through 11, Table 2

6. General relativity supplies the recipe but not the assembly instructions: it prescribes the geometry and the matter needed to induce it, and says nothing about whether you enlarge a wormhole out of the quantum foam or punch a hole through space with an intense beam of negative energy. Davis’s judgement is that the answer will only be found empirically, and he lays out the programme — squeezed-vacuum generators, the other Casimir effects, moving mirrors, Dirac field states, balanced homodyne detection of negative energy, and the physics of trapping and storing it.Section V, Conclusion: The Way Forward

The way in

How to cite it

Eric W. Davis, DIA / AAWSAP contractor (2010) DIRD Traversable Wormholes, Stargates, and Negative Energy https://documents2.theblackvault.com/documents/dia/AAWSAP-DIRDs/DIRD_18-DIRD_Traversible_Wormholes_Stargates_and_Negative_Energy.pdf

Where it sits in the curriculum

• The reference documents and the institutional record
• Wormholes, energy conditions and the negative-energy budget