As per the reported thrust, Mach effect thrusters are still in the race with the Emdrive. These things having very low thrust is not such a big deal for space applications, if the thrust is real.Wasn't it Paul March who believed they could be manifestations of a same phenomenon?
Why does this get so little interest compared to the EM drive?
Along the way, Zvi, John Joseph and Henrik, thanks to the time-honored method of “just staring at” the loop integrand provided by unitarity, also stumbled on a new property of gauge theory amplitudes, which tightly couples them to gravity. They found that gauge theory amplitudes can be written in such a way that their kinematic part obeys relations that are structurally identical to the Jacobi identities known to fans of Lie algebras. This so-called color-kinematics duality, when achieved, leads to a simple “double copy” prescription for computing amplitudes in suitable theories of gravity: Take the gauge theory amplitude, remove the color factors and square the kinematic numerator factors. Crudely, a graviton looks very much like two gluons laid on top of each other. If you’ve ever looked at the Feynman rules for gravity, you’d be shocked that such a simple prescription could ever work, but it does.
Quote from: Star One on 09/05/2015 06:53 pmWhy does this get so little interest compared to the EM drive?I guess because of two things:- thrust magnitude vs background noise: The EmDrive has repeatedly reached several hundreds of millinewtons, while Woodward is stuck in the micronewton range. Even if he managed to carefully get rid of spurious effects and repeatedly showed thrust signatures above the noise, I think people are waiting for some clear scaling.- Nobody in the scientific community paid attention to Shawyer's EmDrive for decades before the replication experiment done at NASA JSC by Eagleworks, which triggered the interest. Even the experiments done by NWPU in China didn't change anything before Eagleworks' results.So it is a good think Woodward's METs are currently investigated by other scientists, with a peer-reviewed paper in the end. Let's hope it will also trigger the interest worldwide.BTW what did Heidi Fearn say about "how to scale the thrust" in the future?
In his work James Woodward refers to the landmark paper of D. W. Sciama :"ON THE ORIGIN OF INERTIA" published in 1953 by the Royal Astronomical Society. In this paper Sciama constructs a tentative theory to account for the inertial properties of matter taking the Mach's principle as a guide.The summary at the begginning of this paper ends as follows :"The present theory is intended only as a model. A more complete, but necessarily more complicated theory will be described in another paper".Does somebody know if this announced second paper on the subject of Inertia exists and how can it be retrieved ?
Yes, see Wikipedia:"A formulation of Mach's principle was first proposed as a vector theory of gravity, modeled on Maxwell's formalism for electrodynamics, by Dennis Sciama in 1953, who then reformulated it in a tensor formalism equivalent to general relativity in 1964."The first paper: Sciama, D. W. (1953). "On the Origin of Inertia". Royal Astronomical Society 113: 34–42. doi:10.1093/mnras/113.1.34The second, more refined paper: Sciama, D.W. (1964). "The Physical Structure of General Relativity". Rev. Mod. Phys. 36 (1): 463–469. doi:10.1103/RevModPhys.36.463