The flagrant ignorance of the wannabe debunker crowd is simply astounding.
The possibility of negative mass and its stunning gravitational field propulsion implications have been featured in the mainstream academic literature for over 60 years. And today, neither the cosmic acceleration attributed to “dark energy” nor the pivotal cosmic inflation era of the Big Bang can be explained without negative gravitation, which is the key requisite component for a gravitational field propulsion mechanism.
And gravitational field propulsion is also the only known and physically viable explanation for the behavior of anomalous aerial devices.
And yet these folks are still going around yapping about the “absurdity” of negative gravitation, aka antigravity, like trained parrots – apparently having refused to actually study the subject for five minutes.
My position on this subject is backed up by a litany of credible peer-reviewed academic papers published in reputable physics journals. Here's a small sample of the mainstream academic literature that's available on the subject:
“Negative Mass in General Relativity,” Herman Bondi, Reviews of Modern Physics, American Physical Society, 1957
Edition Open Access | The Role of Gravitation in Physics | Negative Mass in General Relativity
“Guidelines to antigravity,” Robert L. Forward, American Journal of Physics, 1963
https://mlpol.net/vx/src/1510434945245-0.pdf
“An Exact Solution for Uniformly Accelerated Particles in General Relativity,” W. B. Bonnor and N. S. Swaminarayan, Zeitschrift für Physik, 1964
An exact solution for uniformly accelerated particles in general relativity
“Negative matter propulsion,” Robert L. Forward, Journal of Propulsion and Power, AIAA, 1990
https://arc.aiaa.org/doi/abs/10.2514/3.23219
“The warp drive: hyper-fast travel within general relativity,” Miguel Alcubierre. Classical and Quantum Gravity, 1994
https://arxiv.org/pdf/gr-qc/0009013.pdf
“Motivations for antigravity in General Relativity,” G Chardin, Hyperfine Interactions, 1996
http://cds.cern.ch/record/311392/files/SCAN-9610018.pdf
“CPT symmetry and antimatter gravity in general relativity.” M. Villata, Europhysics Letters, 2011
https://arxiv.org/pdf/1103.4937.pdf
"Is dark matter an illusion created by the gravitational polarization of the quantum vacuum?" Dragan Slavkov Hajdukovic, Astrophysics and Space Science, 2011
https://arxiv.org/ftp/arxiv/papers/1106/1106.0847.pdf
“Metamaterial-based model of the Alcubierre warp drive,” Smolyaninov, Physical Review B, 2011
https://arxiv.org/ftp/arxiv/papers/1009/1009.5663.pdf
"'Dark energy’ in the Local Void,' M. Villata, Astrophysics and Space Science, 2012
https://arxiv.org/pdf/1201.3810.pdf
“Alcubierre warp drive: On the matter of matter,” B. McMonigal, G.F. Lewis, P O'Byrne, Physical Review D, 2012
https://arxiv.org/pdf/1202.5708.pdf
“On negative mass,” Jonathan Belletête and M. B. Paranjape, International Journal of Modern Physics D, 2013
https://arxiv.org/pdf/1304.1566.pdf
“Negative mass bubbles in de Sitter space-time,” Saoussen Mbarek and M. B. Paranjape, Physical Review D, 2014
https://arxiv.org/pdf/1407.1457.pdf
"Physical interpretation of antigravity," Itzhak Bars and A. James, Physical Review D, 2016
https://arxiv.org/pdf/1511.05128.pdf
Anyone opposed to the notion of gravitational field propulsion who can’t provide a similarly comprehensive citation list to refute these respected and provocative peer-reviewed academic physics papers (and nobody can because that body of literature doesn’t exist – all attempts to discredit the notion of negative gravitation have been overturned both theoretically and observationally at this point), should probably spend more time studying and less time exposing their staggering ignorance of this subject.
In fact at this point it's safe to say that negative gravitation is and always has been a fundamental feature of physical law within our universe, and listening to boisterously unenlightened people like Realm is the reason why we were caught off guard by the dark energy observations in the first place. We
should have been expecting to find it, because it's not prohibited by our astonishingly successful general theory of relativity, and as pioneering Nobel laureate physicist Murray Gell-Mann loved to say: "Everything not forbidden is compulsory."