Academic physicists and astrophysicists are still reluctant to use the word “antigravity” because the academic science community has been ridiculing ufo witnesses who described AAVs as “antigravity craft” for so long that the stigma is nearly impossible to overcome at this point. So they couldn’t describe the antigravitational acceleration between the galaxy clusters as antigravity without jeopardizing their careers, and therefore they chose the term “dark energy” instead – that focuses the attention on the (unknown) source of the effect, rather than the effect itself (antigravity). You’ll also see a lot of talk in the literature about “repulsive gravity” and “negative gravitation,” which are just politically correct synonyms for “antigravity.” The stigma is slowly beginning to dissolve now, 20 years after the discovery of antigravity acting between the galaxy clusters. Antigravity is simply the negative pole of the gravitational field; whereas positive gravity accelerates bodies of matter together, antigravity accelerates bodies of matter apart. That’s what’s happening to the galaxy clusters – they’re accelerating away from each other driven by a negative gravitational field, aka antigravity. The negative pole of gravity has always been a feature of the equations of general relativity, but it was ignored, and usually ridiculed, apparently for no other reason than the obvious association between UFOs and antigravity. I'll explain. The principles of gravitoelectromagnetism (GEM) are codified within the Einstein field equation – simply put, this means that all of the dynamical laws that operate on electrical charge have an analogy in the form of the gravitational charge. So for example, if we spin a ring of electrical charges around in a circular manner, we create a magnetic field. A perfectly analogous effect happens when you spin a ring of matter around in a circle; you create a gravitomagnetic field (this is also known as “frame dragging” and “the Lense-Thirring effect”). Now, if you accelerate electrical charges around the small axis of a toroidal inductor (a donut-shaped inductor), you produce a positive electrical field on one side of the inductor, and a negative electrical field on the other side of the inductor. In an analogous manner, if you accelerate matter (gravitational charges) in that same fashion, you produce a positive gravitational field on one side of the toroid, and a negative gravitational field on the other side. So the negative pole of the gravitational field is a fundamental and inescapable feature of gravitational physics, and it always has been. Robert L. Forward elucidated this fact back in 1963 when he wrote this paper, which the academic physics community ignored more or less completely because he used the taboo word “antigravity” in the title: “Guidelines to Antigravity,” Robert L. Forward, American Journal of Physics, 1963 https://mlpol.net/vx/src/1510434945245-0.pdf The now-proven dark energy effect, regardless of its source, is an antigravitational effect – that’s not in question. The galaxy clusters are being gravitationally accelerated away from each other. This means that as an observer recedes from any given galaxy cluster, the attractive acceleration of gravity diminishes slightly faster than the inverse square law, and reaches zero at a specific distance from the galaxy cluster (in other words, the dark energy effect nullifies the gravitational field of the galaxy cluster at that distance). And beyond that distance, an observer would be accelerated away from the galaxy cluster – in other words, an antigravitational field now exists between the observer and the galaxy cluster. And the farther the observer moves away from the galaxy cluster, the greater the gravitational acceleration away from it becomes. Here’s a small sample of the myriad citations about it: “Such cosmological observations have indicated that the universe undergoes accelerated expansion during recent redshift times. This accelerating expansion has been attributed to a dark energy component with negative pressure which can induce repulsive gravity and thus cause accelerated expansion.” “Comparison of cosmological models using recent supernova data,” S. Nesseris and L. Perivolaropoulos, Physical Review D, 2004 https://arxiv.org/pdf/astro-ph/0401556.pdf “Now a group of astronomers using the Hubble Space Telescope have discovered that billions of years before this mysterious antigravity overcame cosmic gravity and sent the galaxies scooting apart like muscle cars departing a tollbooth, it was already present in space, affecting the evolution of the cosmos. ‘We see it doing its thing, starting to fight against ordinary gravity,’ said Adam Riess of the Space Telescope Science Institute about the antigravity force, known as dark energy. He is the leader of a team of ‘dark energy prospectors,’ as he calls them, who peered back nine billion years with the Hubble and were able to discern the nascent effects of antigravity. The group reported their observations at a news conference today and in a paper to be published in The Astrophysical Journal.” “Scientists Examine ‘Dark Energy’ of Antigravity,” Dennis Overbye, New York Times, 11/06/2006 Scientists Examine ‘Dark Energy’ of Antigravity The astrophysicist quoted above, Adam Riess, won the Nobel Prize in 2011 for his co-discovery of dark energy, aka antigravity. “The expansion of the universe appears to be accelerating, and the mysterious anti-gravity agent of this acceleration has been called “dark energy”. To measure the dynamics of dark energy, Baryon Acoustic Oscillations (BAO) can be used.” “Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy,” Chang et al., Physical Review Letters, 2008 https://arxiv.org/pdf/0709.3672.pdf “We have proposed that the dark energy and the recent cosmic acceleration can be the result of the existence of local antigravity sources associated with astrophysical matter configurations distributed throughout the universe.” “A solution of the dark energy and its coincidence problem based on local antigravity sources without fine-tuning or new scales,” G. Kofinas and V. Zarikas, Physical Review D, 2018 https://arxiv.org/pdf/1706.08779.pdf It’s probably worth mentioning that the Big Bang also appears to be a manifestation of antigravity. You’ll hear astrophysicists talk about “the exponential expansion of spacetime” during the cosmic inflation era, which is now the cornerstone of the Big Bang model. Nobody has been able to explain this dramatic rate of acceleration in the early universe, and cosmologists weakly suggest the existence of a new particle coined the “inflaton” to explain it. But cosmic inflation has all of the earmarks of antigravity. The Big Bang is poorly named because it wasn’t an actual explosion – it was the rapid expansion of spacetime itself, and that’s what antigravity is: it’s the metric expansion of spacetime. Just like the Hubble expansion. So in retrospect it seems obvious that antigravity has been an essential feature of cosmic evolution from the very beginning, and astrophysicists are only slowly growing to accept that fact. Once the mainstream astrophysics community accepts that cosmic inflation, the Hubble expansion, and dark energy are all various manifestations of a single antigravitational field phenomenon, then I think we’ll finally be in a position to understand its operational principles and exploit them technologically, as so many of our unearthly visitors have clearly already done.