Rifts Earth Hovercraft: what are they?

[flatline]

WARNING: this thread is specifically about speculation on how Rifts Earth hovercraft might work. If anyone complains that we can't know or shouldn't know how things work, or that we're suggesting things that don't take canon at face value, they will reported to the mods for trolling BECAUSE SPECULATION IS THE WHOLE POINT OF THIS THREAD!

So, how might a hovercycle work?

My group always assumed vectored thrust, but apparently that's not a commonly held belief here on the forums.

If this were Phaseworld, it could be artificial gravity, but I'm not aware that any North American manufacturers have that technology.

Magnetic or electric repulsion wouldn't work very high or over most natural surfaces.

[taalismn]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

[eliakon]

My go answer would be some sort of combination of vectoring fans and maybe some sort of super-science magnetic repulsion system that utilizes the earths magnetic field (which has the super-science advantage of having a handwavium excuse for altitude limits that involves technobabble involving the earths crustal magnetic field or something)

I would normally just say "vectored hover fans" and be done with it (and previously more or less have) until the previous thread where the (novel to me) argument was brought forth that if they were vectored hover fans that the hover bikes would have to be loud.
Since we already know that they are not loud then either the are not vectored hover fans, or they have a way to quite the fans.....Hmmm, white noise generators?

[Alrik Vas]

I think a combination of magnetic and vectored thrust is likely how they work. The mag propulsion keeps them off the ground and awesome maneuvering at low altitude, but when you need to fly over trees, hills or the occasional UAR-1, you'd engage the thrusters and take off much more like a rocket bike.

[guardiandashi]

maybe part of it is something like the "back to the future" hover boards /hover cars, or the captain America /starktech Repulsor tech.

basically both systems seem to generate lift far in excess of what they should be able to based on their observed "thrust effects"

with that said my best guess is that those systems seem to use a combination of mag lev technology (that doesn't rely upon proper surfaces to work (in the case of bttf hover systems)
or the rupulsor tech seems to apply "pressure" in a non obvious way to the environment.

or if rifts space is invoked maybe they use a refined, but relatively low power "traction drive"

[cosmicfish]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that.

It has always seemed to me that in Palladium the rules are a slave to the art, rather than the other way around. That can make it unfortunately difficult to find consistency in the rules.

[cosmicfish]

Well, they have to overcome the force of gravity, and while maglev is appealing because its familiar, the magnetic moment required (considering the paltry change in the vertical component of Earth's magnetic field) would be a few orders of magnitude beyond ridiculous. Anything magnetic able to generate a half-ton of force using only the Earth's field is going to draw everything magnetic within a country mile screaming towards it.

I prefer handwaving them as using vertical reactionless thrusters and ignoring art that shows anything both powered down AND hovering.

[eliakon]

maybe part of it is something like the "back to the future" hover boards /hover cars, or the captain America /starktech Repulsor tech.

basically both systems seem to generate lift far in excess of what they should be able to based on their observed "thrust effects"

with that said my best guess is that those systems seem to use a combination of mag lev technology (that doesn't rely upon proper surfaces to work (in the case of bttf hover systems)
or the rupulsor tech seems to apply "pressure" in a non obvious way to the environment.

or if rifts space is invoked maybe they use a refined, but relatively low power "traction drive"

Ohhhhh have hover tech be another 'space/time friction' technology. That is an interesting spin. Keeps us firmly in the super-science category, but is still in world plausible..... I like it.

[flatline]

Out of curiosity, why are folks so interested in allowing hover vehicles to be quiet during operation?

[eliakon]

Out of curiosity, why are folks so interested in allowing hover vehicles to be quiet during operation?

Because the books seem to imply that they are? And since we know that at least some are quiet enough to count as stealthy. It would be pretty silly to make concealed scout/spy pods....that can't actually sneak anywhere because they are super loud. (real world drones are noisy yes....but they also have real world ranged optics not the myopic short range stuff we find in Rifts. When your cameras have ranges of a few thousand feet then that means you have to get that close). The other issue with them being too loud is that at least hover cycles, jeeps and the like are not all designed to be operated by people in EBA (especially some of the Pre Rifts units) suggesting that they are quiet enough to be used in cities by people not wearing sound baffling.

I don't think that all hover vehicles are silent. But I don't think they are jet loud either. I suspect that they run the gamut of noise from "screw this its a combat unit" to "won't notice its there until it stabs you" with the majority of them falling in the mid range of "Automobiles, Motorcycles, and the like are good examples."

[ShadowLogan]

Well canon does imply that the technology for Rifts Earth (aside from the alien/magical ones like Naruni, Splurgoth, Megaversal Legion, Arkons) is jet thrust based so there is little need for resorting to speculation I think. I think we can rule out super sciency explanations for the actual thrust generation (aside from efficiency) based on canon I think we can say that Rifts Earth Hovercraft are basically variations on the Hiller Flying Platform or related vehicles:
-WB20 pg188 in the 50/50 Hovercycle fluff: "Most tradiational hovercycles have a tendency to stall, freeze (won't go until unfrozen) and cause avalanches." This makes it clear that there are moving parts and/or fluids in the hovercycles that allow them to work.
-WB20 pg188 in the 50/50 Hoverycle fluff: "A muffled "soft-flow" hover jet system causes minimal noise and distrubrance of the snow to help prevent avalanches and similar snow and ice slides".
-WB20 pg32 in the "Travel by Hoversled" section: "The biggest liability of these air and jet propelled vehicles is that although they fly above the snow, their jets can dislodge layers of snow and cause an avalance on glaciers, hillsides and mountain terrains, and blowing snow blasted into the air by the hover jets can obscure the vision of those traveling behind or near them." This makes it clear the vehicles are jet propelled
-SB1o pg102 Engine/Propulsion Systems for 'Bot RCC "A super-sophisticated twin engine system, with bottom and rear jet thrusters for V/STOL capabilities." and again with another option "When not engaged, the jets are completely unnoticable." with "When not Further indication they are jet propelled
-RMB/RUE for the ATV Hovercycle reference the engines as "jets"
-RMB/RUE (and other books with variants likely) for the CS Skycycle reference jets or rockets
-RMB/SB1r Skyking reference jets or rockets
-WB14's hoverbike horse references jets
-WB5 has several hover vehicles with jet/rocket engines or just plain thrusters (which IMHO means jet or rocket)
-WB5 pg134-5's XM-330 Phantom Hover Tank is the only hover vehicle in the book w/no references as above, but does mention "because it moves quickly and silently on a cushion of air." Some might take that to be indicative of hovercraft in general and not a specialized system for the XM-330. I would take it as a system for the XM-330.

I haven't checked every instance of Hovercraft in all the Rifts Books I have access to, but it does seem like given the wide spread publishing (MB/UE, WB5, WB14, and WB20) and the consistency there in, I would probably be surprised if it didn't hold up.

Now talismn mentioned art for NG cycles hovering w/o being in motion. Without knowing specific examples off hand, I'd say it is one of those artistic licence things and leave it at that.

[kaid]

It is a good question. A lot of them refer to jets and rockets but in most of them the art does not really lend itself to anything we would normally consider a jet as most don't have any air intakes or not ones that would be sufficient to make it hover even a little bit. It does not seem to be anti grav because they mention in a few areas CS and triax don't have that tech.

I have to assume they are some kind of ducted fan/jet but many are described as hovering silently even when basically stationary. I pretty much have to just chalk it up in my brain as "FUTURE TECH" because no real application of current tech seems like it would give the results we are seeing described.

[kaid]

One thing to note is that I am almost positive that most hover cycles DO have jets/thrusters but in a lot of cases thats seems like that may not be what is allowing them to hover. There are examples of slow speed stealth mode jet bikes that you can use your prowl with while its active. And I am pretty sure I have read one or two that you can even push them in hover mode while the cycle is off in near complete silence.

A lot of it seems to be some kind of hybrid magnetic/gravitational/super science tech that lets them hover. But that appears not to be capable of impelling much speed/motion in that mode so they have thrusters/jets for speed/manuverability. This kind of thing would also reduce the power of the thrusters needed if they don't need to actually support the weight of the vehicle off the ground AND propel it. So you could get away with pretty small thrusters and perhaps even well baffled ones where at speed they would likely not be very quiet but also not as loud as one would expect from a hover vehicle.

[ShadowLogan]

It is a good question. A lot of them refer to jets and rockets but in most of them the art does not really lend itself to anything we would normally consider a jet as most don't have any air intakes or not ones that would be sufficient to make it hover even a little bit. It does not seem to be anti grav because they mention in a few areas CS and triax don't have that tech.

I have to assume they are some kind of ducted fan/jet but many are described as hovering silently even when basically stationary. I pretty much have to just chalk it up in my brain as "FUTURE TECH" because no real application of current tech seems like it would give the results we are seeing described.

Well rockets don't need intakes. And I don't think modern (skirted admittedly) hovercraft have anything noticeable like an intake for VTOL unless you count the engine for forward movement.

It occurs to me though that these rocket/jets could be styled after something like "lightcraft" or an old World Book Encyclopdia experiment I recall from the 1967edition in the Rocket Entry (I have access to copy of said hard copy edition).

[cosmicfish]

They don't appear to work via anti-grav, because that technology is specifically called out as superior in the PW / Three Galaxies books. Magnetic, as I already mentioned, would have massive side effects at the ridiculous levels necessary to make it work. Rockets require propellant, and there is no indication that most of these vehicles (in particular the nuclear-powered ones) require any. Fans would indeed require air intakes, but they can be surprisingly small (note: modern hovercraft do have air intakes, but they often look like exhaust tubes, and regardless, skirted hovercraft are not really analogous to Rifts hover vehicles).

Any lift source (other than anti-grav) must be capable of exerting >1g in order for the vehicle to fly, and I have a hard time seeing why you would use a different technology for vertical and horizontal thrust with these vehicles. Assuming that some kind of super-science reactionless (i.e., no propellant) thruster is involved, it would need to be running in order to fly, so power off = sitting on the ground, but would not necessarily make much noise on it's own.

As to why some are stealthy at low speeds but obvious at high speeds, there could be a number of reasons for that (admittedly, not many good reasons!) unrelated to the propulsion method.

[taalismn]

Out of curiosity, why are folks so interested in allowing hover vehicles to be quiet during operation?

If you got hovercraft that can hover at a parked standstill, without deafening everybody nearby, then relying primarily on that aspect of their propulsion while moving(slowly) is attractive as an aerial prowl...no clanking/crunching over ground cover/litter...so you can sneak up on people. It's the closest thing to getting a heavily armed weapons platform up unnoticed behind somebody*.

*Back in the day when I was playing Twilight 2000 in college, one of the 'no way in HELL!' moments was when our GM snuck a Russian TANK behind a group of RANGERS in the middle of a FOREST. This was so absurd on so many levels that it got the GM looked at with deep suspicion, and led to rumors of 'secret Soviet flying saucer tech' about the game. Of course, with the big Triax hovertank, you CAN now do that, but not with a 1970's-vintage T-80...

Of course, in reality, said hovervehicle would be a howling banshee kicking up dust and debris, and you'd be getting ground echoes bad enough to make people physically sick from the noise...not to mention leaf-burn and exhaust poisoning....

[glitterboy2098]

actually most of the noise from a hover system is going to be the turbines providing the thrust. without combustion, they will be quieter. and even today there has been great strides in engineering the moving parts and exhuast to be much quieter. (various methods.. new better bearing systems and other areas where parts interact, new materials for less vibration and provide better insulation, and it turns out you can cancel out a lot of the noise of fan/turbine blades by engineering them with shapes that emit frequency cancelling tones. in rifts, where you have designer molecules and things like metamaterials and the like, it wouldn't be too hard to believe that the amount of noise has been reduced even more.)

[ShadowLogan]

Rockets require propellant, and there is no indication that most of these vehicles (in particular the nuclear-powered ones) require any

This is in part why I suggested Lightcraft and the World Book Encyclopedia Experiment, both create thrust by use of the ambient external air, without pulling it inside the vehicle first, to create thrust. Lightcraft uses lasers (also a microwave version) work by super-heating the air causing it to explode. The 1967 World Book Experiment ionized the air and the object having itself the same charge create repulsion and thus thrust.

[cosmicfish]

Rockets require propellant, and there is no indication that most of these vehicles (in particular the nuclear-powered ones) require any

This is in part why I suggested Lightcraft and the World Book Encyclopedia Experiment, both create thrust by use of the ambient external air, without pulling it inside the vehicle first, to create thrust. Lightcraft uses lasers (also a microwave version) work by super-heating the air causing it to explode. The 1967 World Book Experiment ionized the air and the object having itself the same charge create repulsion and thus thrust.

Not having the book, I cannot comment on the World Book experiment, but Lightcraft was theorized as a way of making the engine external to the craft - if you mount of the laser ON the craft then you have a very inefficient vehicle for no good reason. Plus, expanding pockets of super-heated air strong enough to lift a half ton are not going to be stealthy at all.

[kaid]

actually most of the noise from a hover system is going to be the turbines providing the thrust. without combustion, they will be quieter. and even today there has been great strides in engineering the moving parts and exhuast to be much quieter. (various methods.. new better bearing systems and other areas where parts interact, new materials for less vibration and provide better insulation, and it turns out you can cancel out a lot of the noise of fan/turbine blades by engineering them with shapes that emit frequency cancelling tones. in rifts, where you have designer molecules and things like metamaterials and the like, it wouldn't be too hard to believe that the amount of noise has been reduced even more.)

Even with the fan noise deadened which they are doing good strides at you still get some eyebrow raising stuff like just reread the NG2 write up of hover bikes. Most NG2 hover bikes have a mode where they can be parked and on but not moving so you can just pull them along with a rope. This apparently is quiet enough not to disturb animals. Even if the fans make no noise at all you are still dealing with enough air force being projected to keep an object that weights hundreds of pounds in the air with no skirt. Just the noise of the air itself and all the leaves/branches/rocks and what not getting flung hither and yon by the force of the air should make this kind of stealth impossible using any kind of fan/ducting/jet system. This is one of those cases of its probably best not to think about to hard because in the end baring some other hovering force being involved it does not make any real sense as written.

[Alrik Vas]

They expect it would be quiet because they say thrust, but are actually thinking a speeder from star wars.

[flatline]

They expect it would be quiet because they say thrust, but are actually thinking a speeder from star wars.

This is my thinking as well.

[kaid]

They expect it would be quiet because they say thrust, but are actually thinking a speeder from star wars.

This is my thinking as well.

Yup that is kinda how I always thought of them as well but again this is a case of a hybrid hover craft. Some kind of repulsive force that is just on that provides its cushion off the ground and basic hovering and engines for manuvering/propulsion. If you don't have to keep something that weighs a few hundred pounds off the ground by brute force you could indeed make some very baffled thrusters/ducted fans that could be made to be very quite at least at low speeds. I expect them to still be pretty noisy if you have the throttle down but even so it would not be as loud as it otherwise would be.

[Blue_Lion]

They are rift tech. Rift tech is never full explained it just is. It may or may not use some advanced form of currant tech or a tech that is not yet created.

[flatline]

They are rift tech. Rift tech is never full explained it just is. It may or may not use some advanced form of currant tech or a tech that is not yet created.

Please see the first post in this thread where I warn about this kind of defeatism.

So speculate what kind of tech it might be. What properties does it have? What effects does it have on the immediate environment? Are there any quirks that the players should know about (doesn't work over water...makes a lot of noise...attracts/repels items that respond to magnetism or are electrical conductors...easily tracked for some reason...that sort of thing)?

[kaid]

They are rift tech. Rift tech is never full explained it just is. It may or may not use some advanced form of currant tech or a tech that is not yet created.

Please see the first post in this thread where I warn about this kind of defeatism.

So speculate what kind of tech it might be. What properties does it have? What effects does it have on the immediate environment? Are there any quirks that the players should know about (doesn't work over water...makes a lot of noise...attracts/repels items that respond to magnetism or are electrical conductors...easily tracked for some reason...that sort of thing)?

On the plus side while they never really describe hover cycles clearly on how they do what they do they at least all are pretty good about being pretty direct on noise levels/ability to go over water and if so how deep and things like that so game play wise its pretty easy to work with its just that if you actually spend some time trying to see how they can work it seems like there is something else going on there than just pure thrust vs mass.

[Zer0 Kay]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

Nah they found a gas several time lighter than helium allowing even metal objects to float she the internal cavity is filled with the gas. The gas is called pullmyfingerium.

[Alrik Vas]

Seems legit, Zer0.

[Hotrod]

Hovercraft come in various types. It's a catch-all category for low-altitude flying/hovering vehicle.

The first type of hovercraft is similar to what we have today. A lot of air gets blown under a vehicle's skirt-thing, and that makes it float on water and land. The New Navy has a vehicle that works this way. It's pretty noisy.

The second type of hovercraft uses some kind of jet/rocket propulsion to achieve lift fly around. These are very noisy. The original Rifts book had a hover cycle with some kind of plasma or gas shooting out the bottom. That's a good example of this type.

The third type of hovercraft uses forces that don't require Newton's laws of motion to float and move. A crude modern example would be this electromagnetic floating skateboard or a maglev train. Triax's hover-tanks would be a good example. The propulsion systems of these vehicles would be virtually silent, though other systems (power, weapons, ventilation, cooling) would likely make some noise.

[glitterboy2098]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

actually, i'm curious. where are the examples of hovercraft floating when turned off? i've not yet encountered anything to indicate such.

[kaid]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

actually, i'm curious. where are the examples of hovercraft floating when turned off? i've not yet encountered anything to indicate such.

I think this may be confusion based on stuff about some NG hover bikes. I reread one of the passages and if you glance at it it sounds like its hovering while turned off but the bike is still on basically just idling and in idle mode it is hovering and can then be pulled along. Apparently its completely or near completely silent in this mode. This is one of the things that lends to some question as to how do the hover things hover. I don't care how quiet your engines and thrusters are keeping a 1k LBS vehicle suspended in the air a couple feet via any kind of thrust or fan/jet/duct type engine is going to be pushing out an ENORMOUS amount of airflow that simply cannot be silent. It may not be true anti gravity but there deffinately seems to be some kind of other effect going on that creates the baseline hover capability.

Clearly there are traditional hovercraft too though but those are all described in ways that one would expect. They are pretty noisy obvious things typically amphibious military vehicles.

[eliakon]

Hovercraft come in various types. It's a catch-all category for low-altitude flying/hovering vehicle.

The first type of hovercraft is similar to what we have today. A lot of air gets blown under a vehicle's skirt-thing, and that makes it float on water and land. The New Navy has a vehicle that works this way. It's pretty noisy.

The second type of hovercraft uses some kind of jet/rocket propulsion to achieve lift fly around. These are very noisy. The original Rifts book had a hover cycle with some kind of plasma or gas shooting out the bottom. That's a good example of this type.

The third type of hovercraft uses forces that don't require Newton's laws of motion to float and move. A crude modern example would be this electromagnetic floating skateboard or a maglev train. Triax's hover-tanks would be a good example. The propulsion systems of these vehicles would be virtually silent, though other systems (power, weapons, ventilation, cooling) would likely make some noise.

This is actually a fairly good point.
I suspect that 'hovercraft' is turning into a catchall term that covers a wide range of different things which explains how it can have different properties in different vehcicles...
Sort of like the term "car" or "Automobile" the like can cover a wide range of things which gets wider as tech advances.

[Dog_O_War]

I don't care how quiet your engines and thrusters are keeping a 1k LBS vehicle suspended in the air a couple feet via any kind of thrust or fan/jet/duct type engine is going to be pushing out an ENORMOUS amount of airflow that simply cannot be silent.

Maybe, but it is possible to both curb and direct sound waves - maybe that is what some of the stealth-model bikes are doing?

[Blue_Lion]

They are rift tech. Rift tech is never full explained it just is. It may or may not use some advanced form of currant tech or a tech that is not yet created.

Please see the first post in this thread where I warn about this kind of defeatism.

So speculate what kind of tech it might be. What properties does it have? What effects does it have on the immediate environment? Are there any quirks that the players should know about (doesn't work over water...makes a lot of noise...attracts/repels items that respond to magnetism or are electrical conductors...easily tracked for some reason...that sort of thing)?

I did speculate at what it possibly is. Any giving vehicle could be a advance form of currant tech, or some unknown tech. Hover like TW is used as a catch all phrase by PB so it is a case by case basis to sort out. (PB use to use TW to explain every magical items including ones that clearly should not have been classified as such.) The writers use such blanket categories makes it impossible to make a blanket statement that every thing listed in the category falls under one category true category. That is part of the nature of Rifts.

[Shark_Force]

I don't care how quiet your engines and thrusters are keeping a 1k LBS vehicle suspended in the air a couple feet via any kind of thrust or fan/jet/duct type engine is going to be pushing out an ENORMOUS amount of airflow that simply cannot be silent.

Maybe, but it is possible to both curb and direct sound waves - maybe that is what some of the stealth-model bikes are doing?

well you're not going to get very far (literally) unless you let the thrust outside of the vehicle at some point, and it kinda needs to be traveling fairly rapidly to generate any meaningful lift if it's using anything we could remotely comprehend with our level of science.

really, you're pretty much limited to either deciding that it is a physical impossibility, or that it is SCIENCE!!!!! and as such is not bound by our understanding.

which is really just one more thing to add to the pile in any event.

[Dog_O_War]

I don't care how quiet your engines and thrusters are keeping a 1k LBS vehicle suspended in the air a couple feet via any kind of thrust or fan/jet/duct type engine is going to be pushing out an ENORMOUS amount of airflow that simply cannot be silent.

Maybe, but it is possible to both curb and direct sound waves - maybe that is what some of the stealth-model bikes are doing?

well you're not going to get very far (literally) unless you let the thrust outside of the vehicle at some point, and it kinda needs to be traveling fairly rapidly to generate any meaningful lift if it's using anything we could remotely comprehend with our level of science.

really, you're pretty much limited to either deciding that it is a physical impossibility, or that it is SCIENCE!!!!! and as such is not bound by our understanding.

which is really just one more thing to add to the pile in any event.

I don't quite get what you're saying here; the bikes are not riding on sound waves. I am saying the engine noise and the local thrust sound could be directed.

[Hotrod]

Gravity is a conservative force that is speculated to work via particles called gravitons, which have never been directly observed. Every type of particle, in theory, has an anti-particle. Therefore, it might be possible to produce anti-gravitons which create forces that run counter to gravitons. Create enough anti-gravitons going in the same direction, and you might be able to achieve lift.

If I had to speculate, I'd say that hovercraft of the silent type create some sort of anti-graviton field between the vehicle and a finite volume of matter beneath it so that the volume of matter it pushes off gets a stronger-than-normal gravity. This would have to be balanced in such a way so that the hovercraft would maintain a fairly steady altitude over solid matter. Perhaps the anti-graviton field only goes down to a certain depth beneath the vehicle (beyond this depth, the anti-gravitons tend to collide with gravitons and annihilate); that way, if the vehicle is too low, then there's too much "push-off" matter in the ground, and the force balance raises the vehicle. if it's too high, then there's too little "push-off" matter in the anti-graviton field, and the vehicle goes down.

So yeah, anti-graviton emitters. That's my story for silent hovercraft with SCIENCE!

[The Beast]

Gravity is a conservative force that is speculated to work via particles called gravitons, which have never been directly observed. Every type of particle, in theory, has an anti-particle. Therefore, it might be possible to produce anti-gravitons which create forces that run counter to gravitons. Create enough anti-gravitons going in the same direction, and you might be able to achieve lift.

If I had to speculate, I'd say that hovercraft of the silent type create some sort of anti-graviton field between the vehicle and a finite volume of matter beneath it so that the volume of matter it pushes off gets a stronger-than-normal gravity. This would have to be balanced in such a way so that the hovercraft would maintain a fairly steady altitude over solid matter. Perhaps the anti-graviton field only goes down to a certain depth beneath the vehicle (beyond this depth, the anti-gravitons tend to collide with gravitons and annihilate); that way, if the vehicle is too low, then there's too much "push-off" matter in the ground, and the force balance raises the vehicle. if it's too high, then there's too little "push-off" matter in the anti-graviton field, and the vehicle goes down.

So yeah, anti-graviton emitters. That's my story for silent hovercraft with SCIENCE!

Wouldn't that be more likely how the G-drives in the Three Galaxies work?

[glitterboy2098]

Gravity is a conservative force that is speculated to work via particles called gravitons, which have never been directly observed. Every type of particle, in theory, has an anti-particle. Therefore, it might be possible to produce anti-gravitons which create forces that run counter to gravitons. Create enough anti-gravitons going in the same direction, and you might be able to achieve lift.

If I had to speculate, I'd say that hovercraft of the silent type create some sort of anti-graviton field between the vehicle and a finite volume of matter beneath it so that the volume of matter it pushes off gets a stronger-than-normal gravity. This would have to be balanced in such a way so that the hovercraft would maintain a fairly steady altitude over solid matter. Perhaps the anti-graviton field only goes down to a certain depth beneath the vehicle (beyond this depth, the anti-gravitons tend to collide with gravitons and annihilate); that way, if the vehicle is too low, then there's too much "push-off" matter in the ground, and the force balance raises the vehicle. if it's too high, then there's too little "push-off" matter in the anti-graviton field, and the vehicle goes down.

So yeah, anti-graviton emitters. That's my story for silent hovercraft with SCIENCE!

Wouldn't that be more likely how the G-drives in the Three Galaxies work?

yes. and we are told specifically that Rifts Earth lacks that technology.

[taalismn]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

actually, i'm curious. where are the examples of hovercraft floating when turned off? i've not yet encountered anything to indicate such.

Pretty sure early on in the Rifts Graphic Novel Machinations of Doom, the burster's hovercycle is shown floating at a parking standstill.
Then again, it's been some time since I've seen my copy of that tome.

Apparently, though, judging from the NG sourcebook illos, you can idle and tow hovercycles without too much trouble, so, yeah, anti-gravity.

[flatline]

What about very high voltage electrodes that induce a charge in the ground beneath to repel against? Wouldn't work at higher altitudes, but perhaps that explains how they might hover when idle and close to the ground.

Would require something very much like a perfect insulator to protect the electrode. My memory of these things is pretty weak, but I think the voltage would be required to oscillate so the electrode would probably have to be a superconductor of some sort, but I'm pretty confident those exist on Rifts Earth.

[glitterboy2098]

I also assumed absurdly efficient vectored thrust, but we've seen multiple examples of art of the NG hovercycles floating while not under power, so that shoots that. And since these are supposedly pure-tech vehicles, TW- or ambient-PPE side effect is out of the question.
Maybe the air's gotten incredibly dense on Rifts Earth and stuff is just floating around like in a fishbowl?
Pure handwavium,

actually, i'm curious. where are the examples of hovercraft floating when turned off? i've not yet encountered anything to indicate such.

Pretty sure early on in the Rifts Graphic Novel Machinations of Doom, the burster's hovercycle is shown floating at a parking standstill.
Then again, it's been some time since I've seen my copy of that tome.

Apparently, though, judging from the NG sourcebook illos, you can idle and tow hovercycles without too much trouble, so, yeah, anti-gravity.

which doesn't mean he actually turned it off

[Shark_Force]

What about very high voltage electrodes that induce a charge in the ground beneath to repel against? Wouldn't work at higher altitudes, but perhaps that explains how they might hover when idle and close to the ground.

Would require something very much like a perfect insulator to protect the electrode. My memory of these things is pretty weak, but I think the voltage would be required to oscillate so the electrode would probably have to be a superconductor of some sort, but I'm pretty confident those exist on Rifts Earth.

if you can induce a charge in the ground, you should be spraying dirt all over the place. and how are you inducing a charge in the ground only? we've got an improvement over using the earth's magnetic field, certainly, because now your electromagnetic field doesn't need to be nearly as strong, but you're still putting out a field that by definition is capable of holding up a thousand pounds or more at distances of likely well over a meter. if we assume full altitude is possible, up to about 5-6 meters in many cases.

anyone standing underneath wearing metal objects should probably be pulled into the air.

basically, it either works on some principle we don't currently understand, or it shouldn't work at all. which is fine, i mean, rifts is supposed to have some super-science, so it's ok if rifts tech is beyond our comprehension (and it is also just a game, so it doesn't really matter if the science checks out at all). certainly i don't think this is more egregious than body armour that somehow instantly disperses kinetic energy so that you don't get liquified inside your armour when you're hit by a railgun slug.

[ShadowLogan]

Not having the book, I cannot comment on the World Book experiment, but Lightcraft was theorized as a way of making the engine external to the craft - if you mount of the laser ON the craft then you have a very inefficient vehicle for no good reason. Plus, expanding pockets of super-heated air strong enough to lift a half ton are not going to be stealthy at all.

There are videos of lightcraft tests up on Youtube. Yes Lightcraft is supposed to move the engine and power source off the craft, but that imposes certain restrictions in where it can go and when. Doesn't help with the noise aspect, but it would give a rough frame work to use as is, but also one that could be potentially modified. For instance, what if Rifts engineers because of the advanced lasers (miniaturized combat lasers) decided to trade efficiency of Lightcraft's basic design for added mobility/freedom of movement (from the the off-platform laser/generator, which restricts when/where you can use it). Could also trade it for a variant that uses microwaves, but that would require the MiO communities not to have tampered with orbiting senders in the course of 200+years and those senders to still be around w/o assistance for that period of time.

As for the World Book Experiment pg360 (vol16 "Q/R"): emphasis in text "A working Model of an Ionic Rocket, left, is suspended like a pendulum. A strong charge of electricity applied to the model produces ions that cause the rocket to swing a short distance." & next paragraph down "When the switch is closed, positive charges flow into the rod and concentrate at the point. These charges attract electrons from air molecules around the point. The air molecules become positively charged ion. These ions and the positive ions in the point repel each other, causing the ionized air to move backward and the rocket to move forward." Next is a graphic showing this, then it gets into the materials needed to construct this and instructions for doing so (going into and filling pg 361).

Gravity is a conservative force that is speculated to work via particles called gravitons, which have never been directly observed. Every type of particle, in theory, has an anti-particle. Therefore, it might be possible to produce anti-gravitons which create forces that run counter to gravitons. Create enough anti-gravitons going in the same direction, and you might be able to achieve lift.

If I had to speculate, I'd say that hovercraft of the silent type create some sort of anti-graviton field between the vehicle and a finite volume of matter beneath it so that the volume of matter it pushes off gets a stronger-than-normal gravity. This would have to be balanced in such a way so that the hovercraft would maintain a fairly steady altitude over solid matter. Perhaps the anti-graviton field only goes down to a certain depth beneath the vehicle (beyond this depth, the anti-gravitons tend to collide with gravitons and annihilate); that way, if the vehicle is too low, then there's too much "push-off" matter in the ground, and the force balance raises the vehicle. if it's too high, then there's too little "push-off" matter in the anti-graviton field, and the vehicle goes down.

So yeah, anti-graviton emitters. That's my story for silent hovercraft with SCIENCE!

Wouldn't that be more likely how the G-drives in the Three Galaxies work?

yes. and we are told specifically that Rifts Earth lacks that technology.

We are also told in the Skill Description in RUE pg318 & RMB pg29 in the pilot Hovercraft Skill Description "These vehicles can be tricky, because they utilize several air jets and directional thrusters that push the craft along,above the ground, on a cushion of air."

So unless otherwise indicated in the text specifically (like 3G/Naruni for Ex) for specific examples then hovercraft use air jets for propulsion. I guess the real question here should be how they generate those air jets.

What about very high voltage electrodes that induce a charge in the ground beneath to repel against? Wouldn't work at higher altitudes, but perhaps that explains how they might hover when idle and close to the ground.

Inducing it into the ground would also mean that the charge has to to travel through the air into the ground meaning you lose some of that energy in the transition. You'd be better of giving the air itself a charge to repel against (this is the premise of the World Book 1967 edition hands on activity experiment I mentioned previously, though here they use it to create horizontal thrust)

[taalismn]

[
which doesn't mean he actually turned it off

Okay...'low energy idling'. If you're going into a bar to do some drinking(or waiting for a contact), usually you don't keep your vehicle on full-lift mode unless you're a) not concerned about giving the impression you're ready to bolt at a moment's notice, or b) you have a really efficient powerplant and you don't mind wasting gas/power on rider-less hovering while you go about your business.
In any case, it's clear it's not straightout vectored thrust holding the thing up like that.

[glitterboy2098]

as i recall the hoverbike in question is a nuclear powered vehicle.

[Shark_Force]

As for the World Book Experiment pg360 (vol16 "Q/R"): emphasis in text "A working Model of an Ionic Rocket, left, is suspended like a pendulum. A strong charge of electricity applied to the model produces ions that cause the rocket to swing a short distance." & next paragraph down "When the switch is closed, positive charges flow into the rod and concentrate at the point. These charges attract electrons from air molecules around the point. The air molecules become positively charged ion. These ions and the positive ions in the point repel each other, causing the ionized air to move backward and the rocket to move forward." Next is a graphic showing this, then it gets into the materials needed to construct this and instructions for doing so (going into and filling pg 361).

well, that might be slightly less noisy since you wouldn't strictly speaking need a fan, but it's still going to sound like extremely fast winds and kick up a lot of dust, i would imagine (that is, provided you're throwing enough air to lift 1000 lbs off the ground). hardly what i would call silent (though again, it may very well be a lot less loud than a hovercycle powered by a conventional jet engine).

[glitterboy2098]

i've actually built an 'ionic rocket'. used enough power to blackout a house, barely could move a sheet of paper.

NASA does better, but their version is still very very very low thrust. and by their nature they don't get high thrust.

[taalismn]

as i recall the hoverbike in question is a nuclear powered vehicle.

Still wouldn't want to run the engine more than you have to...especially if the propulsion/lift system has moving parts. Sure, turning off the lift systems doesn't affect the radioactive decay rate of whatever isotopes are running the nuke RTG, but if you're using vectored thrust primarily, turbine bearings wear, parts overheat, unnecessary wear and tear, even at low levels of acrivity...
I mean, even if your electric car is hooked up to a power feed, would you want to leave the engine idling while you go shopping? Even if the electricity was free?

[Zer0 Kay]

Seems legit, Zer0.

Yup, too legit. Too legit to quit.