I have an idea to create a hovercar, not the kind we have now with the giant fans and the blanket of air, but the kind of hovercars you see on starwars... Now, if you think that this is impossible using current-day technology and are about to click away from this page, DON'T! Because you can make one of those hovercars using current day technology...

So, I have no idea if this can actually be done mass-produced as the technology is currently under development and has lots of limitations, that would make it very hard to remove some of the limitations required to make the hovercar...

Anyway, all you need is a water fuel cell (a tank full of water that uses electrolysis to separate hydrogen from oxygen, then burn them, turning them into water again, and the process starts again...), anyway, that is connected to a twin-linked ion engine.

The ion engine by itself won't be powerful enough to sustain a stable lift on a 1-tonne car, but two will, but you will need lots and lots of complex algorithms to make both work in usison and as one ion engine. Anyway, you need to refill the water every once in a while, and you'll need to recharge the battery every once in a while, and don't forget that you need a constant supply of xenon (the inert gas that is used as propellant in ion engines)...

Anyway, you'd need all of the above, after joining the ion engines, you'd need like 5 more to manage propulsion, and movement (i.e. strafe), but you cut that down, you'd need a separate tube that leads to the propulsion chamber, which of course will propel the car... But for movement, you'd need something other than ion engines, so as a substitute, you'd need an intake fan that would intake lots and lots of air, and compress it in a compressor unit, then you'd need to blow it out and while you're doing that, put a bit of hydrogen at optimal mix and spark it, BAM! The car has movement...

So, you basically have one ion engine for "hovering", one ion engine for propulsion, and a compressor unit for movement...

There is only one flaw with this, unless you'd want to waste so many litres of xenon, the car would accelerate so slowly, and might take up to 3-4 minutes to reach around 100km (guessed, don't have necessary algorithms to calculate ion engine throust capacity at near sea-level), so it would be really slow to speed up... That is probably the only flaw with this, and the higher the car goes, the less xenon it would require... So it may indeed make roads almost completely obsolete...

Ion engines require incredibly large amounts of energy to power them, and can't really be used in an atmosphere containing any other ions. They also need large supplies of whatever it is you're going to ionise, and are no good at initially accelerating an object, especially in our atmosphere. Nice idea for use in space, but unlikely to work in Earth's atmosphere.

Well, then maybe we could put portable fusion reactors on the cars and give 'em MBPT ion engines, after all, the MBPT thrusters DO provide up to 60000mN of thrust

Currently all our fusion reactions have required much more energy to initiate them than you get back from the reaction, making them somewhat pointless. Depending on how science advances it might be possible, who knows? You'd also need to store the initial fusion material, along with the products, and have some way of removing the products every so often.

In a perfect world, that 60000mN of thrust would give you an acceleration of 0.06ms^-2, assuming your car weighs a ton. So, to reach 30MPH would take you almost 4 minutes, and a 0-60 time of 447 seconds! Of course, being in an atmosphere, there would be air resistance which would probably prevent the vehicle from moving at all

I'm not sure what you intend to suggest for such "thrust".

Ion is out of the question, for sure. Simple thrust air - well, It has been done. Check out the harrier jump jet - so I'm sure we all could use super-powerful turbines on our cars. That's only the technical challenge, the social challenge is (far) worse, in my opinion.You have to deal with people who can't fly, "Drunk flyers" haha, and all the other crud you get on today's roads. Plus, I don't totally see the need in today's world, except (tall) cities and really hilly/windy roads. Maybe not even cities per-say, as the only real advantage such cars would bring is the ability to land at a higher level, but most buildings aren't nearly high enough to be useful.

I'd say cars are here for another century at least. Oddly enough, by the time they are with these flying machines, I wouldn't be surprised if they were all AI controlled. By this point, it's entirely possible that some sort of feasible propulsion system would of also been discovered.

This post has been edited by Live-Dimension: May 25 2008, 10:05 AM

As far as I can see, there are at least two issues that need to be overcome before we go about driving hovercrafts.

1. Weather immunity/resistance

When I was young, I was proud to have drafted a blueprint of what could have been a fine hovercraft (it relies on a set of high-speed fans) until a classmate asked me, "What if a wind blows?" See, we may be able to accelerate hovercrafts up to a hundred kph but, when a moderate wind blows, bam! We have a highway full of crashed hovercrafts simply because some people just couldn't drive in their own lane

2. Traction

When Dr. Robotnik raced against Sonic, he used a hovercraft to eliminate friction. That way, he was able to reach high speeds in a short amount of time. However, his contraption was rather difficult to manage when he comes to sharp turns. See, for a hovercraft that has no friction, there is also no traction! Maneuverability is rather difficult, braking, even harder.

Well, aside from these two, there's the problem with energy sources, but I'll leave that to our planet's brilliant physicists