This STAIF 2007 presentation by Dr. Richard Obousy describes an advanced space-propulsion concept based on modifying the local cosmological constant to facilitate an expansion/contraction of spacetime around a spacecraft to create an exotic form of field-propulsion. This idea is analogous to the Alcubierre bubble, but differs entirely in the approach, utilizing the physics of higher dimensional quantum field theory, instead of general relativity.
"In the spirit of Morris, Thorne and Yurtsever these warp drives, provide an unique and inspiring opportunity to ask the question 'what constraints do the laws of physics place on the abilities of an arbitrarily advanced civilization'. In this paper a new and innovative mechanism to generate the necessary 'Alcubierre warp bubble' is proposed. The main focus of the paper is to demonstrate that the manipulation of the radius of one (or more) of the extra dimensions found in quantum gravity theories, creates a local asymmetry in the cosmological constant which could be used to propel a space vehicle.
At such an early stage in the theoretical development of this idea it is challenging to make predictions on how this 'warp drive' might function. Naively one could envision a spacecraft with an exotic power generator that could create the necessary energies to locally manipulate the extra dimension(s). In this way, an advanced spacecraft would expand/contract the compactified spacetime around it, thereby creating the propulsion effect." -- Dr. Richard Obousy
Windows Media 10 and Google Video Player formats.