James Woodward is the primary researcher and theorist in this area. He has written a book "Making Starships and Stargates".
In the book Woodward walks through all of the physics and theories. He describes the history of the theories and experiments.
He describes his reasoning and why his approach to the problems of inertia, mass are engineering exploitation of it are plausible based on an interpretation of accepted physics.
Here is the exact quote from the Foreward from John Cramer -
"Many of the theoretical physicists who work with general relativity have fundamental objections to the very idea of wormholes and warp drives, which they consider to be unphysical. Some of them have decided that one should erect a "picket fence" around those solutions of Einstein's equations that are considered to be physically reasonable and to place exotica such as stable traversable wormholes, faster-than-light warp drives and time machines in the forbidden area outside the fence, excluded because it is presumed that nature does not allow such disreputable objects to exist. They are, in effect, attempting to discover new laws of physics that would place restrictions on GR solutions."
Looser quotes that cover the picket fence theories -
"Their first attempt at building the fence was called the Weak Energy Condition (WEC)... Average Weak Energy Condition (AWEC)...
The WEC, AWEC, and the other similar energy rules are "made up" laws of nature and are not derivable from general relativity. They appear to be obeyed for observations of all known forms of matter and energy that do not fall within the domain of quantum mechanics. However, even for simple situations involving quantum phenomena (examples : the Casimir effect, squeezed vacuum, and the Hawking evaporation of black holes), the WEC and AWEC are both violated.
"...more recently quantum inequalities...quantum field theory cannot be trusted for some applications...missed fundamental calculation by 50 orders of magnitude"
Here is a paper "Wormholes, Time Machines, and the Weak Energy Condition".
For the regular propulsion aspect, they have achieved tens of micronewtons of force in labtop experiments.
For the stargate/wormhole aspect, this is the second term in a key formula which is always negative. He shows how the areas of inertia and mass and the exact nature of the electron are weakspots in current physics and the best work in this area is the work of Einstein and Mach.
I had covered an earlier Woodward paper on the physics of stargates.
His solution depends on understanding the nature of electrons in terms of a semi-classical extension of the exact, general relativistic electron model of Arnowitt, Deser, and Misner (ADM), and Mach's Principle.
The negative bare mass ADM model of the electron can be modified to accommodate quantized spin.
Given some modest amount of everyday type matter, say a few hundred or thousand kilograms, all we have to do is enclose the matter within another presumably thin shell of matter wherein we can change its mass from positive to negative. It would have to become sufficiently negative to null the positive mass of the initial mass of the shell and the matter it encloses. But if we could do that, we would screen the gravitational influence of the matter in the rest of the universe on the matter within the thin shell.
Find a way to screen our electron from the gravitational potential due to the rest of the universe, the denominator would become of order unity and the exotic bare mass of the electron – 21 orders of magnitude larger than its normal mass and negative – would be exposed. Do this to a modest amount of normal stuff and you would have your Jupiter mass of exotic matter to make a traversable stargate – if the negative bare mass ADM model of elementary particles is a plausible representation of reality.
John Cramer in the Foreward notes that the density of dark matter from the quantum field theory density was off by 50 orders of magnitude from the result calculated from cosmic background radiation observations and other physical observation. Since quantum field theory is way off on the energy content of vacuum, then the restrictions it places on metric engineering cannot be taken seriously.
There are many useful insights in the book.
It will help get a better understanding of advanced physics and why certain interpretations have issues. Things like how some interpretations of the nature of the electron were resulting in electron spin that was many times the speed of light.
The heat generated by the Mach Effect devices has to be managed.
The Mach Effect devices will degrade over time.
What would really help future work -
Developing modelling codes to help guide design
Creating an infrared window in the experiment so detailed thermal imaging and readings can be taken.
Mach effect propulsion will be better with an array of many devices for enhanced maneurverability (point some in different directions to change the angle of movement) and smaller units are easier to cool and multiple units allow for some to fail while the overall system continues to work
It is a very worthwhile book to understand the landscape of the physics which must be understood to get to very advanced propulsion and any possible develop of wormholes for travel.
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