In the interests of fun and entertainment, I had hoped that the debate about anti-gravity devices and inter-stellar travel would take off so that I could at some stage throw in the ace that I keep in my back pocket.
Please note: I am not talking about using anti-gravity as a means of enabling fuel efficient travel in the terrestrial realm, although contradicting issues of scale and energisation will still apply.
Well, I can't wait any longer so here it is, and it's a question that contains its own answer. What disturbs me about it is that for all of the Discovery Channel type documentaries, UFOlogy, mystery and conspiracy theory programmes and publications so few debunkers actually use this ace card.
So, to the question, "Why would Aliens, let alone us, strive so hard to harness the weakest of the known electro-magnetic forces in the Cosmos in tryng to create a propulsion system in order to travel swiftly through space?"
The thing is, an anti-gravity device is only of use in order to escape the gravitational influence of the planetary body at the start of the journey into space. Having got into space, all things being relative, the effects of any anti-gravity device may well be of use as a deflector opposing the gravitational influence of bodies that one's ship would not want to bump into. However, its usefulness for propulsion will be zero. The craft will still require some other means of propulsion either a fueled engine or perhaps a solar sail, whatever.
Consider then, this further problem. To date all of the so called anti-grav' devices we have seen demonstrated (fact or faked) have required large inputs of energy. The equipment for such inputs will need to be carried on the spacecraft and the larger the craft the greater the payload of the generating equipment and any fuel that may be required for it. All that stuff will negate any potential benefit of the system once the craft is in space where gravity is not the problem since what one wants then is velocity. In fact, being attracted to other objects in space has its uses. Even the early interplanetary missions with spacecraft such as the Voyagers were directed on trajectories that took advantage of the other planetary bodies to accelerate the craft on their journey through our Universe.
This all leaves me with another question. Why is it that no-else seems to mention this tiny little problem with anti-gravity and off-world UFO's? I suspect it's one of the little secrets for a private joke within the hallowed halls of science and technology. After all what better way to protect their own standing, esteem and privilege if the alternative anti-science mob are pre-occupied with chasing the unobtainable. A bit like chemists who must raise a chuckle as modern day alchemists, convinced of the truth in ancient myths and legends, still strive to convert lead into gold, methinks. Yes, there must be much mirth about when another anti-gravity device is demonstrated on the interweb.
Correction to one of my earlier posts:
I stated that the Moon's gravity is approximately 1/6th that of the Earth and that the Moon is approximately 1/6 the size of Earth. The ratios are actually closer to 1/5th.