The discovery of isotropic, homogeneous, dielectric--magnetic materials that bend light the "wrong way" created quite a stir in 2001; see the following figure. The situation settled in 2003, with unequivocal demonstrations by several independent groups. A range of exotic and potentially useful phenomenons -- such as negative refraction, negative Doppler shift and inverse Cerenkov radiation -- have been predicted for materials of this type. We call these as negative-phase-velocity (NPV) materials, but at least two other names have common currency too: left-handed materials, and negative-index materials.
Perhaps the potentially most useful application of NPV materials is for the
so-called perfect lenses. Once satisfactorily designed
and fabricated, such lenses could find widespread use
in modern optics, for communications, entertainment, and data storage and retrieval.
More uses would emerge with ongoing research on anisotropic NPV materials.
Instead of concentrating on devices, and inspired by the centenary next
year of Einstein's postulation of the special theory of relativity (STR),
we turned our attention to the marriage
of the theories of relativity and NPV light propagation. We found, a few months ago,
that materials that appear to be of the non-NPV type to
relatively stationary observers can appear to be of the NPV type to observers
moving with uniform velocity.
That result permitted us to
envisage STR negative
refraction being exploited in astronomical scenarios such as, for example, in
the remote sensing of planetary and asteroidal surfaces from space stations.
Quite possibly, space telemetry technologies will be the first to reap the
benefits of STR negative refraction. Application to remotely guided, extraterrestrial mining and
manufacturing industries can also be envisioned. Furthermore, many
unusual astronomical phenomenons would be discovered and/or explained
via STR negative refraction to
collected via telescopes.
Ordinary vacuum (i.e., matter-free space) appears the same to all observers
moving at constant relative velocities. Therefore, NPV propagation in vacuum
cannot be observed by such observers. This could lead one to believe that NPV propagation is impossible
in huge expanses of interstellar space. However, gravitational fields from nearby massive objects will
certainly distort electromagnetic propagation, which is a principal tenet of the general theory of
relativity (GTR) and is indeed used nowadays in GPS technology.
We have now mathematically established that gravitationally affected
vacuum can support NPV propagation
in some directions, at least in spacetime manifolds of limited extent.
Just as scientific
and technological applications of STR negative refraction (by materials)
have been envisaged,
similar and different consequences of gravitationally assisted negative refraction by vacuum are possible. Thus, the potentiality for application
to space telemetry and remotely guided extraterrestrial
manufacturing has been strengthened. Furthermore, our result suggests
the possibility of extensive revision of
current ideas on the distribution of mass in the as-observed universe,
and could affect research on gravitational lensing.
We conjecture that this may be of importance in locating hidden matter in
Reference: Preprint physics/0408021
Acknowledgements: We thank Ms. Stacey Crockett and Kristi Kelso
of SPIE, and Drs. Martin W. McCall (Imperial College London) and Graeme Dewar
(University of North Dakota), for giving us this opportunity to present our findings.
Presentation: Power Point
Authors: A. Lakhtakia and