I don't mind any of the shapes themselves. I just find it wrong somehow that anachronistic scifi designs would survive when they were designed sometimes with near-zero inkling of the realities of the future they're meant to represent. That coincidence kinda boggles my mind.
I'm sure there'll be easy solutions to the shape problem. Buoyant mothership keeping aloft, or driving major spikes into the ground, or a salad bowl shape self-correcting with a low CoG and telescopic stubs of some length that could come out from the hull where the terrain was too sharp, or in the case of a sphere have the outer shell be partly arachnid legs folded such that the segments part of the outer shell were only half of the total leg length. Obviously that last one is expensive in volume, but what're the design criteria and available resources?
Engineers would have a field day with this if there was no need for propellant expulsion so that the drives could be placed almost anywhere on the ship (imagine the implications for stabilizing applications pretty much everywhere in the world right now), and if the engineers were given a minimum of information on the expected terrain.
And even this is really uninformed conjecture.. What if E-M drive tech does literally open up access to orbit and outer space resources so that we can build true mothership sized cruisers from which to launch separate landing craft? The solar system would probably quite easily be colonized, given time for life support tech to make it feasible, and then you'd (IMO) mostly have small passenger vessels travelling to and fro like our present highway system. Only exploration craft would need to be universally polyvalent WRT terrain, and maybe freighters; though they'd probably have their landing spots prepared. Are there really that many places in our solar system (IMO only once interstellar do you really have to have a fool proof landing design) where you'd want to land and M-E drives couldn't allow for a near enough spot that didn't require specialized landing design, or that you wouldn't have been able to recon ahead of time?
If I had to choose one design with humans on board for real time piloting, it'd be spiderish legs with one or two fingertip designs (folded final joint for large area, straight for small area/penetration). Then the shape of the rest of the ship has a lot more leeway.
Pretty unbelieveable...
Well, but in case of Tajmar´s experiment, the spinning disk is the ENGINE right? The ship doesnt necessarily needs to be in that shape. In fact, since its reactionless, it can be completely enclosed inside lets say, a Imperial Star Destroyer shape 
In fact, from what I understand, to lift a HUGE ship, you would probably need several spinning disks (since the material stress in only one HUGE disk spinning would be proportionally huge)
In fact, from what I understand, to lift a HUGE ship, you would probably need several spinning disks (since the material stress in only one HUGE disk spinning would be proportionally huge)
I don't think material stress is the issue since the postulated Heim Drive only creates a gravity field above the spinning disk. But there are several good reasons why designers would use a number of engines within a large ship. Note that current thoughts require the spinning disk to be about 6 meters in diameter in order to lift its own mass, ship mass and payload off the surface. (Of course less powerful drives and wings could work here, too.)In fact, from what I understand, to lift a HUGE ship, you would probably need several spinning disks (since the material stress in only one HUGE disk spinning would be proportionally huge)
The Heim Drive consists of a powerful toroidal magnet (horizontal) with the spinning disk of "special" material above it. That is, the disk and the toroidal magnet lie in parallel planes. The gravity field is created in a spray pattern above the spinning disk. The Drive, and everything attached to it (including the pilot) then falls into the gravity field. The mathematics describing this engine are well developed, the direction of the gravity field force is shown mathematically. It all depends on whether or not HEIM Theory is valid.
Note the 6 meter diameter of the disk results in a saucer shape for any ship smaller than, say, 50 feet in its major dimension. The next larger size, two drive units would be a fat cigar, then 3 drive units, a triangle shape. At some point in ship size, the Heim drive geometry no longer dominates ship geometry, and you could put drive units almost anywhere.
As for ships equipt with multiple Heim Drives, the same constraints that govern aircraft engine manufacturing would apply. Reliability, economy of scale, and so forth.
Oh, as for whether or not Heim Theory is valid, probably the most straight forward proof would be to build a Heim Drive and see if it works. We've heard that idea before.
Aero
I see why EEstor and the other ultracapacitors will not work for the MLT application. So far, Barium Titanate appears to be the only commercially available option. I found a paper by some Japanese where they tried various sintering processes to make the bulk material out of the nanopowders. One process, they claim to make the material with a e-r of 70,000. Their other process, using microwave rather than traditional thermal, made a material with an e-r of only 4,000.
Commercially, the material is available in powder form, including nano-powders down to 50nm size. People can probably sinter it into bulk (multi-crystalline) form for you. However, I don't think anyone has made this material in single crystal form, probably because there is no commercial application for it (other than MLT's, that is). I have yet to find any other material that can match or exceed the e-r capability of Barium Titanate.
I saw a couple papers on making ultra high dielectrics from conjugated polymers, but am not able to find out more about this. Such polymers would be attractive because they might be able to take the stress better than BaTiO3.
I think the alternative energy research is going to be of limited utility because of their focus on either thin-film or multilayer materials.
It looks like the options are limited to BaTiO3 and conjugated polymers (if these are being developed) for the dielectric material.
BTW, to me it looks like EEStor is vaporware.
A patent application for producing single-crystal Barium Titanate.
http://www.faqs.org/patents/app/20080200327
I'm wondering if this stuff can be grown in single crystal form as a boule just like silicon and sapphire.
Commercially, the material is available in powder form, including nano-powders down to 50nm size. People can probably sinter it into bulk (multi-crystalline) form for you. However, I don't think anyone has made this material in single crystal form, probably because there is no commercial application for it (other than MLT's, that is). I have yet to find any other material that can match or exceed the e-r capability of Barium Titanate.
I saw a couple papers on making ultra high dielectrics from conjugated polymers, but am not able to find out more about this. Such polymers would be attractive because they might be able to take the stress better than BaTiO3.
I think the alternative energy research is going to be of limited utility because of their focus on either thin-film or multilayer materials.
It looks like the options are limited to BaTiO3 and conjugated polymers (if these are being developed) for the dielectric material.
BTW, to me it looks like EEStor is vaporware.
A patent application for producing single-crystal Barium Titanate.
http://www.faqs.org/patents/app/20080200327
I'm wondering if this stuff can be grown in single crystal form as a boule just like silicon and sapphire.
-
kunkmiester
- Posts: 892
- Joined: Thu Mar 12, 2009 3:51 pm
- Contact:
Would a doped diamond be viable? There are methods now for producing large flawless diamonds, in various colors due to doping. If a proper doping would produce a capacitor of the right value, you could make a pretty big one. You could also see if the method for making the large diamonds can cross over to making large crystals of other materials, resulting in a more desirable device.
Evil is evil, no matter how small
Diamond has a lower e-r than Barium Titanate. According to Paul March, the higher the e-r, the better the effect, assuming it can meet the other specifications. I think for now they are limited to Barium Titanate only. The good news is that it appears there is a way to make it in single crystal form (see the link in my previous post) and it is certainly available in nano-powder form as well.kunkmiester wrote:Would a doped diamond be viable? There are methods now for producing large flawless diamonds, in various colors due to doping. If a proper doping would produce a capacitor of the right value, you could make a pretty big one. You could also see if the method for making the large diamonds can cross over to making large crystals of other materials, resulting in a more desirable device.
I found a paper suggesting that conjugate polymers could make a dielectric of up to 100,000 e-r. I don't know if this has been developed as I can't find any more papers on it (suggesting the researchers gave up).
It seems though that its Barium Titanate or its a bust.
Where does the energy come from?
Hi Paul March & all
One question I've wondered since Woodward's ideas first surfaced was just where does the kinetic energy of the space-vehicle come from? Does his theory actually explain that? Is it conserved overall?
One question I've wondered since Woodward's ideas first surfaced was just where does the kinetic energy of the space-vehicle come from? Does his theory actually explain that? Is it conserved overall?
The Universe is weirder than we can imagine
-
kunkmiester
- Posts: 892
- Joined: Thu Mar 12, 2009 3:51 pm
- Contact:
On the other hand, I'm sure that groups like the trekkies will be able to find the money to build a functional replica of whatever ship they like. Provided you're not using fission reactors, there shouldn't be many limits to who can build a ship, and so you'd get them.I don't mind any of the shapes themselves. I just find it wrong somehow that anachronistic scifi designs would survive when they were designed sometimes with near-zero inkling of the realities of the future they're meant to represent. That coincidence kinda boggles my mind.
You may not get a 1.5Km Star Destroyer though.
Evil is evil, no matter how small
It wouldn't be the first one.kunkmiester wrote:On the other hand, I'm sure that groups like the trekkies will be able to find the money to build a functional replica of whatever ship they like. Provided you're not using fission reactors, there shouldn't be many limits to who can build a ship, and so you'd get them.I don't mind any of the shapes themselves. I just find it wrong somehow that anachronistic scifi designs would survive when they were designed sometimes with near-zero inkling of the realities of the future they're meant to represent. That coincidence kinda boggles my mind.
You may not get a 1.5Km Star Destroyer though. :P
Engineering is the art of making what you want from what you can get at a profit.
Re: Retro-Causal Communications & Star Drives
A helicopter also has a problem if the engines decide to fail. Sure, you have autorotation, but even that has its limitations (and that may be possible with a thing like this too).93143 wrote: Yeah, but once the engines SHUT OFF, gravity takes over. I'm not talking about stability in flight; I'm talking about passive landing stability.
Even a sphere has this problem. If one of the legs breaks, well... spheres roll.
Using this tech for a full launch lifter is pointless anyway. Watch Firefly, Whedon got it pretty much right as far as space faring tech goes: All ships are FTL incapable but most can travel at near-relativistic speeds, and the huge supercruisers never leave space.
On a craft like Serenity, the whole ship is powered by the Mach effect drive while in space (the cool "Firefly Drive" effect), whereas 'conventional' ion and air-breathing thrusters are used for maneuvering and slower flight (e.g. ship-to-ship transit flights, deorbit burns, etc.)
In atmospheric flight, the ship is held level by the Mach drive again (which also provides onboard gravity when off surface), where the air-breathing jets (Polywell powered, anyone?) provide power for flight.
Launching from the surface means the drive is spooled up, and the jets lift the ship up with the same force as used in space. The craft can hover at any altitude and location. Once the planet surface is cleared, speeding up to orbital velocity is done when neccessary (e.g. to conserve power).
Leaving orbit is done pretty much in reverse, Serenity slows down and partly uses the atmosphere's drag to shed off orbital velocity, before going back to hover mode in the troposphere (the Mach drive is spooled up gradually here). Backup landing is possible as the ship's design is an aerodynamic lifting body to a certain extent, but, as seen in the film, trying to land without any power is pretty much a controlled crash.
Because we can.
Re: Retro-Causal Communications & Star Drives
I didn't say "fail"; I said "shut off". For the last time, I'm talking about LANDING STABILITY. Read more carefully.Stoney3K wrote:A helicopter also has a problem if the engines decide to fail. Sure, you have autorotation, but even that has its limitations (and that may be possible with a thing like this too).93143 wrote: Yeah, but once the engines SHUT OFF, gravity takes over. I'm not talking about stability in flight; I'm talking about passive landing stability.
Even a sphere has this problem. If one of the legs breaks, well... spheres roll.
It doesn't matter what the drive system is; if it's landing vertically on uneven terrain it MUST have a minimum degree of stability - see the problems with the Altair lunar lander. The Mach-effect drive removes the aerodynamic considerations that make an SSTO taller than it is wide, and a Mach-effect vehicle doesn't have to fit inside the Ares V's payload fairing, so the stability requirement dominates. The wider the base of support, the better the ability to land on rough terrain in high winds, so unless you're really confident you're never going to be dealing with anything but paved spaceports in calm weather, it's best to keep the design low and wide.
[Granted, the Altair's problem is exacerbated by the fact that the descent stage on the bottom is mostly empty tankage by the time it lands, so the centre of gravity is very high considering the shape. But the principle is valid.]
What do you mean? I can only assume you haven't understood what this is all about. A Mach-effect drive with the hoped-for thrust efficiency and T/W ratio could easily be used for the complete range of drive requirements. A Polywell-powered jet or rocket engine would be much heavier and need thousands of times as much power to deliver the same thrust.Using this tech for a full launch lifter is pointless anyway...
This isn't an antigravity device. It's a thruster. If it proved possible to generate artificial gravity/antigravity with it, well, that would be a secondary effect, and it wouldn't be directly related to the acceleration of the vehicle.
Also, unless the airbreathing engine uses ONLY air (and sheds on the order of a gigawatt of waste heat some other way), it will require substantial coolant/propellant tanks, meaning limited operational capability - maybe one orbital launch and a propulsive entry/landing. Rockets are even worse. Mach-effect drives can't run out of propellant because they don't use any, and shedding waste heat via radiators isn't so bad because there isn't all that much of it. Result? Take off and land as many times as you like; no refueling necessary.
Air-breathing engines have higher Isp and thrust than rocket engines for a comparable amount of power (or fuel flow, if pure chemical is used). Neither is remotely comparable to the efficiency of using ground traction to push against the mass of the Earth, like a car or a tank, and as I demonstrated upthread, even that is vastly inferior to a 1 N/W Mach-effect thruster. Bear in mind that Mach-effect thrusters are predicted to have T/W ratios comparable to those of chemical rockets, ie: pushing 50:1. (There are chemical rocket engines that exceed 100:1, but it's in the ballpark.)
This is what I mean when I say that if Mach-effect thrusters work as well as the proponents hope, it will make most science fiction obsolete. That includes Firefly.
It's possible that if this technology works, but falls short of its hoped-for potential, it could be useful as a space drive but not as a launch engine. But if that happens, it will also be useless for hovering...
Re: Retro-Causal Communications & Star Drives
Not really, even a good hover engine has plenty of uses, think ground-based hover vehicles (cars, trucks, skateboards!) and replacement of helicopters.93143 wrote:It's possible that if this technology works, but falls short of its hoped-for potential, it could be useful as a space drive but not as a launch engine. But if that happens, it will also be useless for hovering...
As for the launch engine 'problem' goes:
Suppose the craft is Polywell-powered and, therefore, has a pretty big power supply up it's engine room to power the Mach drive.
Where conventional launch vehicles *need* to propel their payload to orbital velocity from the start (otherwise it'll fall down again), why not make a Mach drive that pushes down with a steady 1,0g (hover) or just a little bit more, to slowly gain altitude? Even jet engines can make that grade these days (e.g. Harrier and JSF) so that's not even a technological challenge.
Sure, you're not in orbit yet, but you're in space. Once you're up there, normal engines (chemical or ion, I prefer the latter since you've got a Polywell on the back!) can speed up the craft in near-vacuum a lot more efficient than in the atmosphere.
Or gradually change the direction of thrust of the Mach drive once you start increasing orbital velocity (from 'hover' to 'forward'), any way you like it.
And, although this thing is a thruster and doesn't create a gravity field, it IS an A/G device since it can provide a force which counteracts gravity (with no apparent reactive mass). Useful in all apparent cases.
With regarding to landing stability: Any decent pilot will tell you that landing something (aircraft or rotorcraft) on a non-level surface is plain stupid. Counteracting crosswinds is easy if you have a good RCS thruster system.
Because we can.