Hi everyone,
Remember in the backs of comic books, there used to be the ads for x-ray specs, hovercraft, etc.etc…?
How come there has never been a “real” anti-gravity hovercraft? Is it not possible? Is it beyond our realm of knowledge? I’m dying to know!
Thanks!
It’s probably not possible, and it’s definitely beyond our understanding. AFAIK, most physicists contend that antigravity is not possible, or at the very least wildly impractical.
“Antigravity” is currently outside of contemporary physics. (Some physicists even think it’s impossible, although they’re fewer now since Kip Thorne started writing papers.
Search on +“kip thorne” +antigravity to find popular articles
PS, there is a “crackpot underground” who believes that Hoverboards from the movie Back To The Future really exist.
What about using electro-magnetic propulsion? Probably not feasible without having to layer the countryside with metal plates or conductors or what-have-you.
I’m not talking monorail here … I mean honest to goodness self contained electro-magnetic hovercraft… Didn’t Niklas Tesla experiment (or theorize) that it would be possible?
If you allow gravity to be opposed by another force, then a helicopter counts as anti-gravity 
Or how about helium balloons?
If you need to reduce gravity… hmm. Is negative mass theoretically possible?
There is one eyewitness account that has Tesla flying across the countryside on a slablike piece of equipment which launched huge sparks at any barbwire fence it approached.
This isn’t so crazy. Think in this sequence: the Earth is charged negative and the ionosphere is charged equally positive, so we are all living inside a “capacitor dielectric” with a vertical DC electrostatic field of 100 to 400 volts per meter. Suppose we put a negative charge on a large blimp. That blimp should be lifted upwards by the vertical e-field. Yet this force is relatively feeble.
Now what if we build a huge tower which puts out a few tens of megavolts at 5000 cycles per second? This AC EM wave would be trapped between earth and the ionosphere, and it could be MUCH stronger than the earth’s natural DC field. It concievably could lift any object which was charged oppositely. But it’s AC, so “opposite charge” involves a 5KHz high voltage on a driven oscillator device. If the voltages were high enough, such a device would be lifted into the air. But it would only work within a certain distance from the tall “broadcasting tower,” and it would involve astronomically high levels of voltage. Don’t fly too close to any barbwire fences Dr. Tesla!
LOL! Exactly!
It’s not “antigravity” which all the science fiction stories about flying cars are discussing. Instead it’s “repulsion.” Planes and helicopters and hovering rocket ships all use reaction motors, and reaction motors need huge amounts of fuel to hover at constant altitude (since they must accelerate huge amounts of reaction mass.) But reaction motors don’t need any surface to push against, and they work just fine when thrusting sideways.
A repulsion vehicle needs no fuel, but it can only create a vertical force. It would create a force-pair between itself and something on the ground. Or in the case of vertical electrostatic fields, the vehicle would push downwards against the charged earth while pulling the charged ionosphere downwards. Maglev would require some kind of devices on the ground under the vehicle.
Actually, helium balloons are “repulsion vehicles.” When you inflate a helium balloon you make the earth’s atmosphere a bit deeper, and as the balloon feels an upward force, an enormous “footprint” of feeble downwards force must appear on the ground, where this downwards force is equal to the upwards force on the balloon. No fuel needed for hovering.
There was another thread that had links to a site that explained how one of Tesla’s ideas was a sort of helicopter that created a downforce by moving electricly charged air with magnetic fields instead of rotor blades like those ionic breeze things they advertise on TV. If you do a search of this site on Tesla you should find it.
Currently, we can’t really controll gravity, besides of course moving around mass, and it takes a lot of mass to get a noticiable effect on the gravity when you are on the earth’s surface. Gravity is probably the least well understood of the four fundamental forces - we can do all sorts of manipulations of electromagentic forces, and we can do some stuff with strong and weak nuclear forces.
I remember the first time I read about that type of propulsion system was in Larry Niven’s ‘RingWorld’. Of course, since the entire ringworld itself was artifically constructed (a slice of a Dyson Sphere), the vehicles simply replelled again the material in the Ringworld (i.e. the plates were under the ground, supporting it)
What? The Earth itself is very nearly perfectly neutral. If you have a cite for the Earth having a negative charge, I’d like to see it.
What’s this bit of nonsense? Filling a balloon with bottled CO[sub]2[/sub] has the same effect on the atmosphere, but it won’t float upwards.
“There is one eyewitness account that has Tesla flying across the countryside on a slablike piece of equipment which launched huge sparks at any barbwire fence it approached.”
I hope you don’t mean to suggest that Tesla actually did this.
"Actually, helium balloons are “repulsion vehicles.” When you inflate a helium balloon you make the earth’s atmosphere a bit deeper, and as the balloon feels an upward force, an enormous “footprint” of feeble downwards force must appear on the ground, where this downwards force is equal to the upwards force on the balloon. "
This appears to be complete nonsense to me.
There is a lot of pseudoscience flim-flammery associated with Tesla. I hope you’re not falling for it.
I just wanted to take the opportunity to kijack the thread and stand up for bbeaty. First off, the guy knows his stuff, his page has been on my list of bookmarks since what seems like the dawn of the web. Second off, on inspiration from bbeaty’s site, ive read a few books both for and against Tesla’s work. It seems to me that his detractors lie nearly as much as his supporters.
bbeaty, I just want to say its awesom to be breathing the same virtal air as you now.
The idea being that, if we understood gravity as well, we could build antigravity devices? Unfortunately, no. The way to manipulate electromagnetic forces is to move charges around, and the way to manipulate gravitational forces is to move masses around. We understand how to do both, but it takes an awful lot of mass to produce noticeable effects. One example I’m fond of: Consider an apple hanging from a tree. The gravity of an entire planet is pulling it down, but the electromagnetic forces in the tiny stem are enough to hold it up. Point being, that most objects in our Universe interact electromagnetically a lot stronger than they do gravitationally.
Uh, cite please…
10V/M is enough damage electronic equipment if poorly designed and is the maximum required test field for industrial equipment. I find it hard to believe a static field of 100 V/M exsits naturally.
Uh, nevermind…
I got confused between the static field you were talking about and the AC field I deal with at work.