Passenger Drones (Concept of Mine)

[ZooNamedGames]

 

4 minutes ago, KSK said:

Plenty of ways. One of the easiest might be to go to college (assuming you're not already) and speak to your technology transfer office. They should be able to help you, or if they're not willing to help you directly, to give you some advice and put you in touch with the right kinds of people to speak to if you want to try and make a go of your idea yourself. 

Yes, you'll need investment. Yes those investors will want to see a return on that investment. Unless you plan to start making these things in your garage, that's the way the world works. Your investors will essentially be taking on all the risk involved in bringing your idea to market and they're going to want appropriate compensation for doing so. On the other hand it's not like people never got rich by having VCs invest in their companies.

Before doing anything though, I'd recommend putting a business plan together. Taking a long hard look at some of the questions on this thread - and coming up with realistic answers, rather than just 'rule of cool' handwaving - would be a good start. If nothing else that will tell you whether you really want to be dumping all your time and energy into this project.

Well if there's anything I've learned from business and real life; its futility. I can spend every waking hour making something and trying to perfect it and by the time I have it ready; there will ALWAYS be someone with a better and more effective idea.

So yeah; I'll leave it to the next person. He will do better in every aspect, so I might as well save the effort and just do something more entertaining.

[Darnok]

8 minutes ago, ZooNamedGames said:

 

Well if there's anything I've learned from business and real life; its futility. I can spend every waking hour making something and trying to perfect it and by the time I have it ready; there will ALWAYS be someone with a better and more effective idea.

So yeah; I'll leave it to the next person. He will do better in every aspect, so I might as well save the effort and just do something more entertaining.

Natural selection is what drives progress

Why person with less efficient idea should have same chances as person with better ideas? Check others work and try to came up with something better, cheaper for manufacture or hire your self in patent office and steal some ideas like some very famous Albert probably did

[adsii1970]

4 hours ago, Red Iron Crown said:

I don't think control is a huge issue with flying cars, autopilot is very mature and we could likely see a net improvement in air safety by removing pilots from the loop if it was socially acceptable. It would be trivial to beat automotive safety numbers.

Liability issues are a big thing that can't be ignored, it would have to be established who pays for what in a predictable manner if insurance companies are going to underwrite these (and you need insurers for this idea to fly).

But the biggest issues are noise, efficiency, and available landing sites. It's not possible to make a heavier-than-air VTOL that doesn't move a ton of air, and moving that air will always make noise and potentially damage the surroundings. So you'd need somewhat specialized landing sites that are kept free of debris, and in a dense environment like a city you'd need an awful lot of them, too. Efficiency will always be worse than an equivalent tech ground vehicle, because it has to do the work of maintaining speed and altitude versus maintaining speed alone.

If we step back a bit, is this really the direction we want to be going anyway? Do we want to trade the suburban sprawl that was enabled by good roads and cheap cars for subsuburban sprawl where people are commuting hundreds of km a day? Do we want to replace our relatively clean and efficient cars with something more energy intensive, with all the environmental footprint increase that implies?

[edited by adsii1970 for relevant content]

There are also some other considerations that I have yet to see mentioned. If such vehicles were auto-piloted, would they be autonomously controlled or through some centralized local traffic control system? Maybe a combination of both? Then the issue becomes would such a system, whether it is an autonomous auto pilot or centralized traffic control system be immune to a cyber attack? (for reference, remember this? https://nakedsecurity.sophos.com/2013/04/12/plane-hacked-remotely-android/)

Imagine the havoc if an auto pilot or centralized control facility were to be hacked. Imagine ISIS hacking a major city's system, such as Paris, and reprograming to have every vehicle in the air to fly into a landmark or government building. Imagine what would happen if sort a system would fail and the passengers had no way of gaining control of the drone... I think these fears are some of the many reasons why we do not already have completely automated aircraft.

The landing and take off zones required would actually negate the "time saver" argument for the use of such passenger drones. The laws of physics are hard to break unless you're George Lucas and you have a sci-fantasy movie franchise going. Too many people imagine Coruscant style vehicle usage:

And yes, while something like this would make passenger drones and flying cars useful, the problem is that there is no way any of this is possible. You would have to be essentially ferried to and from those designated zones and as we all know, waiting for the bus can be extremely excruciating when you are in a hurry.

The other issues you raise, especially about urban sprawl, will progress either with or without the whole passenger drone system as proposed by its supporters here. Right now, we see Japan, France, and China investing a lot of money in new high speed rail projects that will be able to transport people from the rural areas into the major metropolitan hubs. Within the United States, we see similar trends in the American northeast and California. As these become readily available, efficient, and the public sees them as being safe, the hinterlands of the major metropolitan areas will expand to match the new developments in technology. Eventually, as the human population grows, we may see buildings like the ones seen in Star Wars - up to a mile or more high, and even archologies, much like the ones featured in SimCity 2K.

1 hour ago, ZooNamedGames said:

Hydrogen power is very effective... Available and works. So... How wouldn't this work better?

Hydrogen fuel cells are HEAVY and would add to the weight of the craft. This would mean you would have to spend more energy than conventional transportation means just to produce enough thrust to maintain lift. This defeats the argument that it would benefit because of it being more economical. A better fuel source is fusion power; and I will bring up the Foundation series by Isaac Asimov. We are already witnessing development of micro-technology in nuclear reactor design (https://www.engadget.com/2007/12/19/toshibas-building-a-micro-nuclear-reactor-for-your-garage/) where Toshiba is making one that measures 20' x 6'; within thirty years, it is predicted that we could have reactors the size of a small igloo cooler - that you can literally take with you for an unlimited power supply. Asimov wrote about this very development in the 1950s and 1960s. If these can produce as much power as claimed, then this may be the answer to the energy question for such craft as are being proposed here.

[Snark]

I see several issues, here.

First and foremost:  There are several giant and unavoidable problems with the idea of "everyone has a flying car" and there are millions of the things everywhere:

• It's unavoidably going to generate a LOT of noise.
• It's unavoidably going to consume a LOT of energy.
• It's unavoidably going to be a LOT riskier than ground transportation.

...There's not really any way to argue, there.  You can claim "well, we can improve the noise and the energy and the risk with technology"-- but ground transportation will benefit from those, too, and will come out the winner.  So unless you can come up with a really convincing technical solution to all three of the above (which you certainly can't, if you don't have a solid engineering background), then it's a non-starter from the get-go.

 

8 hours ago, ZooNamedGames said:

We want to upgrade. Personally the idea of living in this world as it is with cars is cool for 2000, but in 2040, I think we should have more.

Going to flying cars is a step backwards.

Energy is a problem.  Humans use far too much of it.  We spend it profligately, and we're already paying the price for a century of irresponsible squandering of resources.  Energy is a scarce resource that needs to be spent wisely.  Wasting it is a really bad idea.

The progress of technology lets us do more and more with less energy.  We get more efficient.  Take a car from 60 years ago:  giant steel behemoths with engines that are appallingly thirsty by today's standards.  Now I drive a trim little hybrid that gets 50 MPG.  That's progress.  I've got a phone in my pocket that runs off a little battery... to get that much computing power would have taken kilowatts just a few decades ago.  That's progress.

At least in the US, our cars are a huge percentage of our energy usage, and it's a real problem.  The solution needs to involve getting better at using energy-- not squandering it.  And flying cars are going to spend energy like a drunken sailor; there's simply no way to avoid it.

So from a macroeconomic / environmental perspective, it simply makes no sense at all.  If you could find a way to generate many times our current energy output... without emitting carbon... without generating dangerous waste... without producing excessive waste heat or other deleterious impacts... and do it all cheaply... then maybe that would be a starting point.  But people have been trying to do that for decades, and there's no sign it'll get solved any time soon.  So if you're waiting on that in order to enable your flying-cars-for-everyone, you'll have a long wait.

To me, 2040 doesn't mean "flying cars".  It means widespread, efficient mass transit.  And extremely energy-efficient ground transportation.  And really good data communication and telepresence so that people can do stuff from where they are, rather than having to haul their carcasses miles back and forth each day.

 

8 hours ago, ZooNamedGames said:

Hydrogen power is very effective... Available and works. So... How wouldn't this work better?

Lots and lots of reasons.

First of all, hydrogen is not an energy source, it's a storage mechanism.  You have to get the energy from somewhere in order to make it-- thus the macroeconomic issues discussed above.  Saying "we'll run things on hydrogen" is like saying "we'll run things on batteries"-- sure, but what do you charge the batteries with?

Second, it has crappy energy density.  Liquid hydrogen has a density of 70.85 g/L.  Gasoline is around 750 g/L.  Combine that with their heats of combustion, and we find that gasoline stores 3.5 times the energy per volume that liquid hydrogen does.

3.5 times, and far more practical.  Liquid hydrogen needs heavy pressure vessels, lots of thermal insulation, is extraordinarily explosion-prone, and can't be stored long-term.

The fact of the matter is... gasoline is an extraordinarily effective high-density power source.  It's why our vehicles run on it, despite its many disadvantages.  It's simply too good at what it does.  You want a power-hungry flying car, you'll either have a really short range, or else you'll need to come up with something a lot more high-density than gasoline.  In other words, magic technology that doesn't exist and likely won't for the foreseeable future

.

8 hours ago, Red Iron Crown said:

That has a burn time of under ten minutes, is ~90% propellant by mass, drops stages like it's nobody's business, has no provision for remaining in a fueled state for any significant period of time, and uses rocket engines which offer the highest TWR of any engine type. Do you see why these properties are not compatible with a consumer vehicle? Are you really proposing hydrolox rocket engines for a flying car?

^ This sums it up pretty well.

 

 

7 hours ago, Kryten said:

If you seriously think you can design some revolutionary transport system, then design it and then go drum up some venture capital.

^ This.  It's how innovations happen and get turned into technology for the masses.

 

7 hours ago, ZooNamedGames said:

I'd love to; but the people who would fund it want money from it.

Well, yes, obviously.  Nobody's going to want build anything unless there's a prospect of making money.  It's how the world works.  What's your point?

7 hours ago, ZooNamedGames said:

How can I, a 18yo high school student manage to get any benefit for an idea when I have nothing to prove it's worth?

Exactly!  You've put your finger on it precisely.

Bear in mind that what you've just described is simply an idea, which of itself is worthless.  Ideas are a dime a dozen.

What actually has value is not some nebulous "idea", but rather a plan.  Something that has actual, hard scientific and engineering thought put into it.  Nobody's going to just hand you money without having some idea that you're even vaguely credible.  Unless you can back up your "idea" with good hard engineering and economic analysis, you might as well just be one more crackpot trying to sell a perpetual motion machine, as far as potential investors are concerned.  If they're going to be putting money into something, they need to be convinced that you know what you're talking about.

So:  you have an idea?  And you want to make it happen?  Then you need to do lots and lots and lots of hard work, with all the detailed and rigorous engineering analysis that entails.  Until and unless you do that, there's no reason for anyone to believe.

7 hours ago, Kryten said:

If literally all you have is an idea, there's no reason for anybody to give you anything.

^ This, exactly.

7 hours ago, ZooNamedGames said:

Which is the problem. Someone has a possible solution but since it's only an idea no one to test it. Who knows; someone could've thought of the solution to everything but because it's some old hobo's idea we disregard it and tell him to work his wages.

And the reason it's "only an idea" is that you, personally, haven't made it into something more than that.  In other words:  you have provided no real value.

Yes, actually building flying cars would take millions of dollars.  But doing enough engineering analysis to demonstrate (convincingly) the technical feasibility on paper is something that you don't need megabucks for.  All you need is scientific/engineering know-how and a whole lot of hard work.

Of course we disregard "some old hobo's idea".  Because "ideas" are a dime a dozen.  They only have value when there's a lot of know-how and hard work behind them.  Elbow grease first, benefit later.  It's how things work.

7 hours ago, Kryten said:

 You haven't demonstrated that you even have an idea that's any better

 

6 hours ago, ZooNamedGames said:

How am I supposed to with no budget?

 

6 hours ago, Kryten said:

You design and you make calculations. Engineering without calculations is basically just an unsubstantiated opinion.

^ This.  Exactly this.

 

[ZooNamedGames]

1 hour ago, Snark said:

I see several issues, here.

First and foremost:  There are several giant and unavoidable problems with the idea of "everyone has a flying car" and there are millions of the things everywhere:

• It's unavoidably going to generate a LOT of noise.
• It's unavoidably going to consume a LOT of energy.
• It's unavoidably going to be a LOT riskier than ground transportation.

...There's not really any way to argue, there.  You can claim "well, we can improve the noise and the energy and the risk with technology"-- but ground transportation will benefit from those, too, and will come out the winner.  So unless you can come up with a really convincing technical solution to all three of the above (which you certainly can't, if you don't have a solid engineering background), then it's a non-starter from the get-go.

 

Going to flying cars is a step backwards.

Energy is a problem.  Humans use far too much of it.  We spend it profligately, and we're already paying the price for a century of irresponsible squandering of resources.  Energy is a scarce resource that needs to be spent wisely.  Wasting it is a really bad idea.

The progress of technology lets us do more and more with less energy.  We get more efficient.  Take a car from 60 years ago:  giant steel behemoths with engines that are appallingly thirsty by today's standards.  Now I drive a trim little hybrid that gets 50 MPG.  That's progress.  I've got a phone in my pocket that runs off a little battery... to get that much computing power would have taken kilowatts just a few decades ago.  That's progress.

At least in the US, our cars are a huge percentage of our energy usage, and it's a real problem.  The solution needs to involve getting better at using energy-- not squandering it.  And flying cars are going to spend energy like a drunken sailor; there's simply no way to avoid it.

So from a macroeconomic / environmental perspective, it simply makes no sense at all.  If you could find a way to generate many times our current energy output... without emitting carbon... without generating dangerous waste... without producing excessive waste heat or other deleterious impacts... and do it all cheaply... then maybe that would be a starting point.  But people have been trying to do that for decades, and there's no sign it'll get solved any time soon.  So if you're waiting on that in order to enable your flying-cars-for-everyone, you'll have a long wait.

To me, 2040 doesn't mean "flying cars".  It means widespread, efficient mass transit.  And extremely energy-efficient ground transportation.  And really good data communication and telepresence so that people can do stuff from where they are, rather than having to haul their carcasses miles back and forth each day.

 

Lots and lots of reasons.

First of all, hydrogen is not an energy source, it's a storage mechanism.  You have to get the energy from somewhere in order to make it-- thus the macroeconomic issues discussed above.  Saying "we'll run things on hydrogen" is like saying "we'll run things on batteries"-- sure, but what do you charge the batteries with?

Second, it has crappy energy density.  Liquid hydrogen has a density of 70.85 g/L.  Gasoline is around 750 g/L.  Combine that with their heats of combustion, and we find that gasoline stores 3.5 times the energy per volume that liquid hydrogen does.

3.5 times, and far more practical.  Liquid hydrogen needs heavy pressure vessels, lots of thermal insulation, is extraordinarily explosion-prone, and can't be stored long-term.

The fact of the matter is... gasoline is an extraordinarily effective high-density power source.  It's why our vehicles run on it, despite its many disadvantages.  It's simply too good at what it does.  You want a power-hungry flying car, you'll either have a really short range, or else you'll need to come up with something a lot more high-density than gasoline.  In other words, magic technology that doesn't exist and likely won't for the foreseeable future

.

^ This sums it up pretty well.

 

 

^ This.  It's how innovations happen and get turned into technology for the masses.

 

Well, yes, obviously.  Nobody's going to want build anything unless there's a prospect of making money.  It's how the world works.  What's your point?

Exactly!  You've put your finger on it precisely.

Bear in mind that what you've just described is simply an idea, which of itself is worthless.  Ideas are a dime a dozen.

What actually has value is not some nebulous "idea", but rather a plan.  Something that has actual, hard scientific and engineering thought put into it.  Nobody's going to just hand you money without having some idea that you're even vaguely credible.  Unless you can back up your "idea" with good hard engineering and economic analysis, you might as well just be one more crackpot trying to sell a perpetual motion machine, as far as potential investors are concerned.  If they're going to be putting money into something, they need to be convinced that you know what you're talking about.

So:  you have an idea?  And you want to make it happen?  Then you need to do lots and lots and lots of hard work, with all the detailed and rigorous engineering analysis that entails.  Until and unless you do that, there's no reason for anyone to believe.

^ This, exactly.

And the reason it's "only an idea" is that you, personally, haven't made it into something more than that.  In other words:  you have provided no real value.

Yes, actually building flying cars would take millions of dollars.  But doing enough engineering analysis to demonstrate (convincingly) the technical feasibility on paper is something that you don't need megabucks for.  All you need is scientific/engineering know-how and a whole lot of hard work.

Of course we disregard "some old hobo's idea".  Because "ideas" are a dime a dozen.  They only have value when there's a lot of know-how and hard work behind them.  Elbow grease first, benefit later.  It's how things work.

 

 

^ This.  Exactly this.

 

Well I give and revert to my earlier statement- someone else will do it better and cheaper.

[Snark]

14 minutes ago, ZooNamedGames said:

Well I give and revert to my earlier statement- someone else will do it better and cheaper.

...Or, perhaps, not at all, and we end up doing something totally different but equally impressive. 

(It's fun sometimes to pick up science fiction magazines from the 1950s, and see what everyone pictured as the future of computers.  "We have these big computers now, right?  Well, in the future, they'll have REALLY HUMONGOUSLY BIG computers!  The size of a city!")

 

[Nuke]

say i want to get a multi-rotor craft with electric motors powered by off the shelf apus. im assuming a 500kg craft.

500kg seems about right for an airframe (includes pilot/avionics/engine), and i figure that is going to take 4900 kn of thrust to counteract gravity, but to have a chance at controlled flight id actually take that to 7500kn.

so we know what we need to lift it. so what can we get, lets start with ebay. whats the biggest bldc motor we can get? i found a 50kw motor that can spin at 6600 rpm and weighs just short of 6kg. how many of those do i need?

use one of those static force propeller calculators, lets stick a 3 foot prop on there and i get 965 newtons of thrust, drawing 55kw of power. but lets assume 875 so that it doesnt burn out our motor. i need 8.5 of those to fly. lets carry 12 instead for redundancy, you can loose 3 and not die. our power requirements are now 600kw. these motors surprisingly only weigh in at 72kg. now lets find an apu that can carry all this.

this is where i hit problems, i did find the numbers 4.4kw/kg and 8Mw/m^3 to give us an idea of weight and size for a gas turbine apu. i dont think anyone manufactures a 600kw apu, so you are gonna have to build it. were looking at 136kg for this system and it will fairly small. that gives us plenty of mass left over for structure, fuel and pilot. though if you want a backup you are going to have to start at square one and redesign it all over again with a 700kg craft in mind.

thats just the basic rundown done over the course of about 15 minutes. but the devil is in the details. im confident that the gas turbine-electric design i proposed earlier would work. engineering is making it work well. i think a good vtol need not rely on down thrust in all flight regimes to stay optimal. once you get off the ground the vtol concept doesnt make any sense. so you want to be able to transition into plane mode and rely on airfoils for lift while letting the motors run low and cool, that way when you want to land you dont need to rely on a bunch of overheated coils and bearings to not die and fire up the backup apu while you are at it.

 

Edited July 28, 2016 by Nuke

[WestAir]

It would certainly have been fun.

[ZooNamedGames]

26 minutes ago, Snark said:

...Or, perhaps, not at all, and we end up doing something totally different but equally impressive. 

(It's fun sometimes to pick up science fiction magazines from the 1950s, and see what everyone pictured as the future of computers.  "We have these big computers now, right?  Well, in the future, they'll have REALLY HUMONGOUSLY BIG computers!  The size of a city!")

 

When I say "it", that's the next big thing. 

Coming from the same books that said we'd be on the moon by the 80s or 90s?

Just now, WestAir said:

It would certainly have been fun.

That's essentially my idea minus the tail. Same shape and all.

[ZooNamedGames]

And I'll make one final post. Many of you have asked for me to at least do some engineering and figure it out.

Well I'll be honest; I can't. I am a high senior who borderline dropped out and is in the bottom of the grade score. I have nearly genius IQ but I haven't looked into chemistry or any math past Alegbra 2. I'm having to retake Geometry because I failed it twice, and am having to retake it. Granted I do have dyscalculia so maybe it that which is holding me back.

So please understand when I say I can't, I literally don't have the capacity to do so.  Being the dreaded "idea guy" is all I have. I have no technical skills, and no physical skills either. So I've got nothing else.

[adsii1970]

@ZooNamedGames: 

Let me be the first to tell you that many of us here do not have a degree in engineering. Don't believe me? Go look at the thread I maintain where the OP is essentially the degrees held or worked on by the many forum users of KSP.

There is nothing wrong with being a dreamer and thinker. Take it from someone who teaches at the college/university level and has for about 14 years. There are too many people going through the motions in life that do not know how to dream, to think of solutions to their problems, or to even consider how to make their place better. I've noticed on other threads you like to think outside the box - and that is common for dreamers.

I'm a dreamer too; because of this, I am constantly reading something non-fiction and it is usually something that caught my mind's eye either on here (the forum), on television, or in simply watching the world around me. While it does give me a wide knowledge base, there are times that my knowledge of any one subject may be limited because at one point, I got bored. Your idea of a passenger drone isn't a bad one - but for now, there are simply too many variables to make it feasible. However, that doesn't mean you listen or even have to listen to the consensus that tells you to go study engineering... or to forget the idea... Many discoveries were discovered either by accident or by a so-called amateur researcher.

50 minutes ago, ZooNamedGames said:

Granted I do have dyscalculia so maybe it that which is holding me back.

So please understand when I say I can't, I literally don't have the capacity to do so.  Being the dreaded "idea guy" is all I have. I have no technical skills, and no physical skills either. So I've got nothing else.

[Edited by adsii1970 for relevant content]

Now to address the more serious elements of your recent comment. I have brain damage from an accident while in the military. Twice my heart stopped beating for over three minutes, but here I am (both incidents were a week apart). I lost my math ability and when I am tired, I slur my speech as if I am intoxicated. I tell you this for one reason - it's not a disability and I refuse to let others tell me it is. It is simply obstacles to overcome. Sometimes I do and sometimes I dont, but I never give up. I'm getting back into music composition, something that I was once a natural at; I am also relearning and self-teaching upper maths (trigonometry and calculus) to myself. I refuse to give in, I refuse to surrender.

So? Ok, you think you don't have the capacity to do what? Learn technical skills? Those can be done through trial and error if you have a serious enough desire. Turn dreams into reality? Well, that's what dreamers do...you find a problem, you create a workable solution to that problem. Physical skills are learned behavior, speaking from a psychological point of view. Did you know that if a cat or dog loses a limb, within three to ten days, they will adapt and overcome by learning the skills needed to balance on three limbs? You're in high school - get serious about your studies, do the best you can. Seek help or visit your local community college and take advantage of the free tutoring services... Man, at your age, your focus shouldn't be on what you cannot do, but on what you can do...

[KSK]

In addition to adsii1970's comments, there's also a perfectly good alternative to acquiring the necessary skills yourself - find somebody else who has them and team up. Pretty much every successful innovation needed the details people to build it but, equally importantly, needed the big picture people to see why it was needed in the first place and inspire others to come together and make it happen.

To use a suitably spaceflight example, I'm sure Elon Musk knows a fair bit about rockets. But more importantly he's put together a team of actual rocket scientists to do all the detailed work and then inspired all the machinists, concrete pourers, cooks, accountants, janitors and what have you to come together and make SpaceX in the first place. Then he inspired them to hang together at the start where nothing ever quite worked and they were on the verge of going bust.

A lot of innovation is also about thinking out of the box - OK so we have this widget here, common as muck, everyone knows about them. But what happens if we add this and then use the two of them together for that..? Maybe something special would happen.

Edited July 28, 2016 by KSK

[Snark]

13 hours ago, ZooNamedGames said:

Coming from the same books that said we'd be on the moon by the 80s or 90s?

Actually, most of them had us colonizing Mars and landing manned missions on the moons of Jupiter by the 90s.  For the most part, they tended to wildly overestimate the future progress of space travel and atomic energy, and wildly underestimate the progress of computer technology.

A fairly common scene in 1950's sci fi:  our hero is steering his fusion-powered ship to land on Pluto or somewhere, and whips out a slide rule to do the calculations...

I recall an early science fiction book (don't remember author or title, but I rather suspect it was Heinlein) that was describing the first manned landing on the moon, written before transistors were a thing.  The lander had no radio... because it would have been too big and bulky and they needed to save weight.  So there was the question of "how will mission control know when he's landed?", and the scheme was that the pilot would scatter a big sack of carbon black around, to make a large blotch that folks on Earth could see with telescopes.  (I remember being indignant when I read that.  Carbon black, really?  That's stupid.  The moon may look "white" to you in the night sky, but actually it's nearly black; its albedo is only 0.05.  If you're going to try to make something really visible, you should be scattering something white, not black.  Guy should have had a sack of titanium dioxide or something.)

But I digress. 

12 hours ago, ZooNamedGames said:

Many of you have asked for me to at least do some engineering and figure it out.

Actually, folks weren't telling you to "do X"-- simply pointing out that "doing X would be needed to accomplish Y."

The fact is, no technical innovation is going to happen without hard nuts-and-bolts engineering analysis and a lot of hard work.  That's simply an objective fact.  It says nothing about who needs to do what.

My reading of what most of what the comments were really about was not so much engineering per se, but rather:  hard work.  Lots of tedious, difficult, hard work.  There's no short cut.  Edison's famous quote that "genius is 1% inspiration and 99% perspiration" was spot on.

12 hours ago, ZooNamedGames said:

Well I'll be honest; I can't. I am a high senior who borderline dropped out and is in the bottom of the grade score. I have nearly genius IQ but I haven't looked into chemistry or any math past Alegbra 2. I'm having to retake Geometry because I failed it twice, and am having to retake it. Granted I do have dyscalculia so maybe it that which is holding me back.

So please understand when I say I can't, I literally don't have the capacity to do so.  Being the dreaded "idea guy" is all I have. I have no technical skills, and no physical skills either.

Well, okay, then.  I understand that it must be frustrating.  That certainly presents a challenge.

Everyone has their limitations, and different people have different ones.  Some limitations may seem discouragingly insuperable.

But a speed bump doesn't have to be a road block.  The really sad cases are the people who don't understand their own limitations.  If you know what your limitations are... then you can work to overcome them, or (if that's not possible) at least steer around them.  There are many paths to "success."

I'm totally willing to take what you say n the quote above at face value, but here's where I respectfully disagree:

12 hours ago, ZooNamedGames said:

So I've got nothing else.

Nonsense.

Everyone has something.  Everyone has some strength, somewhere.  Maybe you're getting frustrated because you've convinced yourself you want to have one particular thing, and you want to have it in a particular way, and your own areas of difficulty are proving to be a barrier to that.  Well, okay then-- figure out something else.  Maybe set a different goal, that is compatible with what you can do.  Maybe figure out a different way to get to the goal.

You don't have to look any further than @adsii1970's inspiring story for an example.  There are plenty of others out there, too.

The one universal constant, in whatever you set out to achieve, no matter what your abilities are:  it's going to take a lot of hard work, doing something.  So figure out what you can do, and get to it.

And-- given your age and inexperience-- it's likely that for a few years at least, the lion's share of that work is going to have to involve not actually doing-the-thing, but training yourself and developing your skills to give you the wherewithal to do-the-thing.  You've barely even started, for cryin' out loud.  Heck, I'm an engineer myself... but I sure wouldn't have been able to design the things I design now when I was 18.

The important thing is to not get hung up on the things you want-but-can't-have-right-now.  Wishful thinking, envy-- those won't help you.  Just figure out what you can do, boil it down to one step at a time, roll up your sleeves, and go after it!

Maybe you can be a flying-car engineer... so, lots of hard work to overcome limitations and become an engineer, first.

Or maybe you can't do that... but maybe you could follow @KSK's advice and find someone who does have that skill set to team up with.  So, in that case, you need to find something else besides engineering that you could bring to the table, that would give some engineer a reason to want to team up with you.  Maybe you could become an expert in finance or business administration, handle the business-model end of things, be the office administrator who keeps the project on track.

Or maybe that doesn't appeal to you... but you could be a teacher, who inspires another generation of students to reach and accomplish something, and you'll watch with satisfaction as someone whom you inspired sets foot on Mars.

Or maybe your biggest asset is an active imagination, so you go find something that lets that imagination be an asset even if it's not harnessed to math and hard engineering-- maybe you could be a science fiction author, or a screenwriter, or any one of a number of useful creative professions.

Whatever you do... I hope you don't let the chorus of no-that-won't-work responses in this thread discourage you.  None of it is a personal criticism of you.  All it really is, is this:  if you post an engineering idea in an engineering forum full of engineering types who think about engineering problems, without any engineering know-how to back up the idea... then you have to expect the idea to get a lively critical analysis. 

It may help to think of it this way:  When a technical person points out a technical problem with your technical proposal, they're not criticizing you; they're simply addressing the technical feasibility of the issue.  In a sense, they're paying you a compliment:  they're taking the trouble to analyze your idea.  If they really thought you were a bozo, they wouldn't even bother.

[RainDreamer]

I am pretty sure that someone out there is already try to make this happen.

Though I imagine it will take us quite a while until we reach a point of population density where transportation on ground is way too busy that no one get anywhere unless they use the vertical axis of movement. that would be when this is likely needed for mass production.

However, I can imagine a more practical function now: rescue/emergency transports.

When you need to transport someone fast in an emergency now from a distant place a helicopter is often called which require a helicopter pilot available. Now if this works, and the autopilot programming is reliable enough, we can have a number of these drones that can be called by on scene paramedics to load up people and send them to nearest medical facility. Can even call several of them at the same time.

[Green Baron]

There are a lot of ultralight or very light helicopters buzzing around. Many of them could serve as a base for your idea, i'd guess (without proof cause i am no engineer neither) that the engineering part is not the cause why it hasn't been done yet, it's rather regulations, certification and legal stuff. There'd be a LOT of new airfields close to each and a lot of confusing traffic situations.

To be honest: i wouldn't want my neighbor to hover over my roof. He's alright with his land-cruiser @50 km/h .... ;-)

 

[wumpus]

18 hours ago, Snark said:

I see several issues, here.

First and foremost:  There are several giant and unavoidable problems with the idea of "everyone has a flying car" and there are millions of the things everywhere:

• It's unavoidably going to generate a LOT of noise.
• It's unavoidably going to consume a LOT of energy.
• It's unavoidably going to be a LOT riskier than ground transportation.

Energy is a problem.  Humans use far too much of it.  We spend it profligately, and we're already paying the price for a century of irresponsible squandering of resources.  Energy is a scarce resource that needs to be spent wisely.  Wasting it is a really bad idea.

The progress of technology lets us do more and more with less energy.  We get more efficient.  Take a car from 60 years ago:  giant steel behemoths with engines that are appallingly thirsty by today's standards.  Now I drive a trim little hybrid that gets 50 MPG.  That's progress.  I've got a phone in my pocket that runs off a little battery... to get that much computing power would have taken kilowatts just a few decades ago.  That's progress.

..

To me, 2040 doesn't mean "flying cars".  It means widespread, efficient mass transit.  And extremely energy-efficient ground transportation.  And really good data communication and telepresence so that people can do stuff from where they are, rather than having to haul their carcasses miles back and forth each day.

Noise: The ascent/decent of a "flying car" is bound to be loud.  This may be the issue that both kills the "flying car" (or more specifically, the personal VTOL craft) and makes the flying car a reality (because then you *have* to taxi several km to the designated takeoff/landing zones).  I don't expect the rest of the noise issues to be significant (if they are a problem, fly higher).

Energy: They almost certainly won't get the efficiency of a Prius.  I'd expect them to get better efficiency than a Ford F-150 (the best selling vehicle in the USA).  From what I can figure from the life cycle of cars and looking at things in terms of l/km (well, really gpm, but lets keep things metric) US vehicles should strive for 90% of a Prius' efficiency (that last bit seems to be bragging rights, but could very well be needed once the Saudi fields pump water).

Risk: Right now, in the USA human controlled ground transportation is the single highest killer of children/teens and a major killer of those under 50 (and likely the biggest in industrialized countries outside of the US).  Degrandfathering human control out of ground transportation appears impossible, but improved autopilots for air traffic don't appear unreasonable.  In the long run you are probably wrong with this one.

Energy: I'm guessing that the biggest issue of energy production (and thus consumption) is nucleophobia.  The large unsolved issue with nuclear fission is the production of nuclear waste.  Thus, compared to all other means of energy production, one form concentrates its pollution into a controllable means while the rest spew thiers forth hither and yon to the winds (and seas and ground).  At some point we should ask ourselves if it is really all that much better to litter all your trash into the wilderness or simply collect it all in a trash can for disposal.  And right now we should know the answer to that.  It used to be said that "diffusion solves pollution", but that was before  somebody checked the chemistry of those pollutants and demanded scrubbing, and then found out that the levels of CO2 were an issue when evenly dispersed across the entire globe.  At some point we have to give up our bias for diffusion and understand that nuclear waste might be a better case of pollution and not a worse one.  PS: don't even ask what Fukushima would have been like if the tsunami swept through the dozens of heaps of coal ash that would have been there without a nuclear reactor.

Mass transit: Only works in areas where "everybody" wants to go to the same place, and preferably from the same place as well.  This implies dense cities (and presumably fission reactors.  I suppose you could have huge solar plantations out in rural areas and use high voltage lines to bring power in, but expect a ton of losses not included in usual expectations of a solar future.  It also might work well if users kept "electric smart/kei/whatever" cars near the "work destination" to improve mobility (and reduce the feeling of lack of independence from the mass transit).

Hydrogen:  Launching stuff into orbit happens to be hydrogen's absolute best case.  Its extreme light weight gives it a huge advantage over everything else.  Now look up recent launches and check how many of them use hydrogen-oxygen (especially for more than just the last stage).  Tell you something?  That the weight issue (which is a tiny advantage to anyone else) doesn't overcome hydrogen's huge disadvantages?  How about air transport?  In aerospace mass is everything.  Ok, in aircraft it isn't quite as overbearing as in space, but it is still huge: the latest big jets can takeoff with 55% or so of their weight in fuel (presumably UK-Down Under flights).  Now try to buy hydrogen-powered aircraft.  Remember, you should be able to double the available mass for tickets/cargo fees by using your favorite fuel (after lengthening the fuselage by a large multiple to carry all that hydrogen), but you still can't find one for sale.  Now ask why anyone else who doesn't obsess over weight all day should be remotely willing to put up with the awfulness that is hydrogen?

Medical/trauma transport: presumably this would be to lower the cost of helicopter transport and reduce the time that land based transport takes.  Assuming an autopilot would throw a ton of political fuel into a fire that already has an overabundance (in the US) of political issues (pilots, drivers, and the entire helicopter business chain would suffer).  There is also the question if cold sleep/hibernation might be a better solution to the "golden hour" problem than hurrying as fast as possible ("you aren't dead until you are warm and dead").

[Snark]

2 hours ago, wumpus said:

Noise: The ascent/decent of a "flying car" is bound to be loud.  This may be the issue that both kills the "flying car" (or more specifically, the personal VTOL craft) and makes the flying car a reality (because then you *have* to taxi several km to the designated takeoff/landing zones).

So if you have to drive many kilometers to takeoff/landing zones, where's the win?  Might as well just drive to where you're going.

2 hours ago, wumpus said:

I don't expect the rest of the noise issues to be significant (if they are a problem, fly higher).

"Fly higher" isn't really a solution, unless you're talking about flying at altitudes of tens of thousands of feet over unpopulated areas.

Helicopters are LOUD.  Ducted fans are loud, too.  A helicopter flying overhead is kind of an annoyance even if it's a couple of thousand feet in the air... now multiply that by tens of thousands.  There is no way that's going to be anything other than a nightmarish noise hazard.

2 hours ago, wumpus said:

 I'd expect them to get better efficiency than a Ford F-150 (the best selling vehicle in the USA).

Why would you expect that?

Trying to keep something in the sky by hurling a torrent of air downwards is incredibly power-intensive.  If you've got something that masses hundreds of kilograms (at least), it's going to use scads more power than any comparably sized ground vehicle.

Transportation is, IIRC, the biggest energy consumer in the US, despite all the advances in efficiency we've made over the last few decades.  Taking that energy requirement and multiplying it severalfold just so people can have "flying cars" seems like a really bad idea to me.

2 hours ago, wumpus said:

Risk: Right now, in the USA human controlled ground transportation is the single highest killer of children/teens and a major killer of those under 50 (and likely the biggest in industrialized countries outside of the US).  Degrandfathering human control out of ground transportation appears impossible, but improved autopilots for air traffic don't appear unreasonable.  In the long run you are probably wrong with this one.

I really don't think so.

My concerns aren't with the control.  Give the technology enough time, and I expect we can have totally automated autopilots that are safer than a human pilot.  Same goes for ground vehicles.  I would love it if, twenty years from now, pretty much all ground transportation is required by law to be automated, and human drivers are a thing of the past-- if it can be proven to be safer, which I expect there's a pretty good chance of.  Humans are terrible drivers.

I'm talking about mechanical safety.  There's simply no way to make a flying car as safe as a ground-based one.  The high fatality rate from ground based cars is mainly due to the fact that humans are terrible drivers; yes, fatalities occur due to mechanical failures, but that's not the big killer.  Most ground-car mechanical problems are nonlethal; the car just stops working, is all.  And when they do become lethal, chances are good that it's lethal mainly to the owner/operator.

That's not the case when you take tens of thousands of tons of steel and hang them in the sky over a densely populated area.  When an airborne vehicle seizes up, it falls out of the sky, and that's dangerous.  Not just to the operator, but to anyone unlucky enough to have a car fall through their roof.  It's why there are so many restrictions on where it's possible to fly.  It's why getting permission to fly drones in urban areas is such a thorny issue.

I'm not saying it's impossible, or that you can't do various things to try to mitigate it... but it's always going to be safer on the ground.

 

2 hours ago, wumpus said:

Energy: I'm guessing that the biggest issue of energy production (and thus consumption) is nucleophobia.

<nice explanation of benefits of nuclear power relative to other souces>

You're pretty much preaching to the choir on this one, I'm a fan of nuclear power. 

However... that's not going to solve the flying-car problem.

When I'm saying "I'm a fan of nuclear power", that's not the same thing as saying it's perfect, or that wasting scads of energy and then building more nuclear plants to compensate is a good idea.  It's kind of like what Winston Churchill said about democracy:  that it's the worst possible form of government... except for all the others.

Nuclear plants are bad.  They're expensive.  They have significant environmental impact.  They generate dangerous waste.  There are security concerns.  I'm in favor of them because, bad as they are, they're better than pretty much everything else that's available.

So by all means, let's build nuclear plants to supply the energy that we have to have... but don't waste energy.  It's better to figure out a way to do what we need to do with half the energy, than to build twice the nuke plants we actually need to.

Flying cars for everyone would be a profligate waste of energy, and that's a bad idea regardless of where the energy ultimately comes from.

 

...Note that a lot of my objections go away if the use case isn't "flying cars for everyone", but a small number of emergency vehicles, as suggested by RainDreamer:

5 hours ago, RainDreamer said:

However, I can imagine a more practical function now: rescue/emergency transports.

When you need to transport someone fast in an emergency now from a distant place a helicopter is often called which require a helicopter pilot available. Now if this works, and the autopilot programming is reliable enough, we can have a number of these drones that can be called by on scene paramedics to load up people and send them to nearest medical facility. Can even call several of them at the same time.

...If it's only a relatively tiny number of vehicles... and if they're only used in emergencies, like medevac helicopters... then this idea looks a lot more attractive.  Noise, inefficiency, expense, environmental friendliness, macroeconomic issues-- they pretty much all become irrelevant.

Even the risk becomes a lot more manageable.  "Flying cars for everyone" requires that the risk has to be no more than that of a safely automated ground vehicle, which is impossible (or, at least, very impractical) IMHO.   But for a flying ambulance or similar emergency vehicle, they don't have to hit that bar.   All that matters is that the risk of the flying vehicle has to be lower than the risk to the victim bleeding on the ground if there's no speedy rescue, and that's a much easier risk target to hit.

[ZooNamedGames]

7 hours ago, Snark said:

Actually, most of them had us colonizing Mars and landing manned missions on the moons of Jupiter by the 90s.  For the most part, they tended to wildly overestimate the future progress of space travel and atomic energy, and wildly underestimate the progress of computer technology.

A fairly common scene in 1950's sci fi:  our hero is steering his fusion-powered ship to land on Pluto or somewhere, and whips out a slide rule to do the calculations...

I recall an early science fiction book (don't remember author or title, but I rather suspect it was Heinlein) that was describing the first manned landing on the moon, written before transistors were a thing.  The lander had no radio... because it would have been too big and bulky and they needed to save weight.  So there was the question of "how will mission control know when he's landed?", and the scheme was that the pilot would scatter a big sack of carbon black around, to make a large blotch that folks on Earth could see with telescopes.  (I remember being indignant when I read that.  Carbon black, really?  That's stupid.  The moon may look "white" to you in the night sky, but actually it's nearly black; its albedo is only 0.05.  If you're going to try to make something really visible, you should be scattering something white, not black.  Guy should have had a sack of titanium dioxide or something.)

But I digress. 

Actually, folks weren't telling you to "do X"-- simply pointing out that "doing X would be needed to accomplish Y."

The fact is, no technical innovation is going to happen without hard nuts-and-bolts engineering analysis and a lot of hard work.  That's simply an objective fact.  It says nothing about who needs to do what.

My reading of what most of what the comments were really about was not so much engineering per se, but rather:  hard work.  Lots of tedious, difficult, hard work.  There's no short cut.  Edison's famous quote that "genius is 1% inspiration and 99% perspiration" was spot on.

Well, okay, then.  I understand that it must be frustrating.  That certainly presents a challenge.

Everyone has their limitations, and different people have different ones.  Some limitations may seem discouragingly insuperable.

But a speed bump doesn't have to be a road block.  The really sad cases are the people who don't understand their own limitations.  If you know what your limitations are... then you can work to overcome them, or (if that's not possible) at least steer around them.  There are many paths to "success."

I'm totally willing to take what you say n the quote above at face value, but here's where I respectfully disagree:

Nonsense.

Everyone has something.  Everyone has some strength, somewhere.  Maybe you're getting frustrated because you've convinced yourself you want to have one particular thing, and you want to have it in a particular way, and your own areas of difficulty are proving to be a barrier to that.  Well, okay then-- figure out something else.  Maybe set a different goal, that is compatible with what you can do.  Maybe figure out a different way to get to the goal.

You don't have to look any further than @adsii1970's inspiring story for an example.  There are plenty of others out there, too.

The one universal constant, in whatever you set out to achieve, no matter what your abilities are:  it's going to take a lot of hard work, doing something.  So figure out what you can do, and get to it.

And-- given your age and inexperience-- it's likely that for a few years at least, the lion's share of that work is going to have to involve not actually doing-the-thing, but training yourself and developing your skills to give you the wherewithal to do-the-thing.  You've barely even started, for cryin' out loud.  Heck, I'm an engineer myself... but I sure wouldn't have been able to design the things I design now when I was 18.

The important thing is to not get hung up on the things you want-but-can't-have-right-now.  Wishful thinking, envy-- those won't help you.  Just figure out what you can do, boil it down to one step at a time, roll up your sleeves, and go after it!

Maybe you can be a flying-car engineer... so, lots of hard work to overcome limitations and become an engineer, first.

Or maybe you can't do that... but maybe you could follow @KSK's advice and find someone who does have that skill set to team up with.  So, in that case, you need to find something else besides engineering that you could bring to the table, that would give some engineer a reason to want to team up with you.  Maybe you could become an expert in finance or business administration, handle the business-model end of things, be the office administrator who keeps the project on track.

Or maybe that doesn't appeal to you... but you could be a teacher, who inspires another generation of students to reach and accomplish something, and you'll watch with satisfaction as someone whom you inspired sets foot on Mars.

Or maybe your biggest asset is an active imagination, so you go find something that lets that imagination be an asset even if it's not harnessed to math and hard engineering-- maybe you could be a science fiction author, or a screenwriter, or any one of a number of useful creative professions.

Whatever you do... I hope you don't let the chorus of no-that-won't-work responses in this thread discourage you.  None of it is a personal criticism of you.  All it really is, is this:  if you post an engineering idea in an engineering forum full of engineering types who think about engineering problems, without any engineering know-how to back up the idea... then you have to expect the idea to get a lively critical analysis. 

It may help to think of it this way:  When a technical person points out a technical problem with your technical proposal, they're not criticizing you; they're simply addressing the technical feasibility of the issue.  In a sense, they're paying you a compliment:  they're taking the trouble to analyze your idea.  If they really thought you were a bozo, they wouldn't even bother.

My something is creativity and occasionally problem solving, just not with mathematics.

I am a writer- take look at my series Recover Vessel. I'd really like to write for games but my current position as mentioned before leaves me as the dreaded "idea" guy who no one cares to listen to.

I see the point though. Thanks.  

[wumpus]

15 hours ago, Snark said:

So if you have to drive many kilometers to takeoff/landing zones, where's the win?  Might as well just drive to where you're going.

"Fly higher" isn't really a solution, unless you're talking about flying at altitudes of tens of thousands of feet over unpopulated areas.

Helicopters are LOUD.  Ducted fans are loud, too.  A helicopter flying overhead is kind of an annoyance even if it's a couple of thousand feet in the air... now multiply that by tens of thousands.  There is no way that's going to be anything other than a nightmarish noise hazard.

IMPORTANT NOTE: "Drones" need not mean "quadcopter".  Drones hit the public conscious with the Global Hawk, which was fixed wing and certainly not a quadcopter.  Quadcopters are great if you don't car about fuel (you are using lithium batteries charged by main power, and power consumption is trivial).  They just don't scale up.  Anything that needs to carry a passenger needs to rely on aerodynamic lift (at least once you complete takeoff).

Yes, I've heard the Goodyear (I think) Blimp go overhead.  Unbelievably loud (think a low flying jet that just *stays* over head moving at ~20mph).  Loud and long.  While mufflers on planes might be unthinkable now, I suspect they were nearly as unthinkable in the days of the model-T (and they had to avoid spooking horses).

Maintaining altitude by forced airflow isn't going to work.  You need to use aerodynamic lift.  Which is why you don't want to have to taxi to a landing strip (the "car" isn't remotely optimized for ground travel) beyond the simple issue of extra distance.  You use aerodynamic lift, you suddenly lose a ton of issues like noise (be prepared to include mufflers on planes).  You might also gain huge issues like stalling, but there are ways about that (note that the only way to get the previously mentioned freewing scorpion to stall was by extremely slow travel: it was even less possible to stall than the vari-eze, and this typically happened only when the propeller was pointing nearly up).

Complexity:  A VTOL aircraft capable of maintaining flight via aerodynamic lift sounds like a recipe for disaster.  Certainly the Osprey (the only high volume example I can think of) is most famous for crashing and killing marines.  On the other hand, the example I keep bringing up didn't have all those issues (of course, it couldn't *quite* manage vertical takeoff/landing) .  See http://www.freewing.com/ for examples (and it appears to be resurrected, at least in internet/possibly vapor form.  I thought the company had died 20 years ago, but these new pages are copyright 2016).  Note that there did exist a variant that supposedly flew straight up, but I was under the impression that it needed more development and was never designed to land that way.  One possible modification to the design would be to let the engines (presumably plural, possibly single in an asymmetric craft that moved the engine between the fuselage and the wing but remain aligned with center of mass/center of pressure) rotate as freely as the wings, and be angled by a tail (think aircraft tailwing) that would pull the engine horizontal as speed (and drag) increased.  Presumably this would let the engines (and propellers) point straight down during launch and land and nearly horizontal during the main flight without introducing a mechanism that would allow this to fail (if the tail structure broke, it would almost certainly fail in the "launch/land" configuration, but that doesn't compare to actuator failure).

I suppose that four or five motors would work to maintain flight in "quadcopter" configuration, and eventually bring the safety it needs.  The transition priod between post-prototype low volume and high volume would be horrific (lots of ways to kill that don't rely on single motor failure).  There is only so much testing you can do, and the public will do crazy things no test pilot would dare.  Using an extra rotor should allow for redundancy (using four *should* work, but expect a lot of stress on the two motors besides the failed motors.  Using five should let you rate the motors much closer to 1/5 the thrust you need.  You still would have all the noise and efficiency issues, and likely not get much faster than land transportation for longer distances.

PS: this is part of the point of my previous example upthread about using a "corvette engine in a  cessna-massed airplane".  You should be able to lower mass so that TWR>1.0, but if you try to maintain those power levels for very long, you will die (especially if the engine is the only thing holding the plane up, or possibly if you take the plane into flutter).  That engine can pull hundreds of horsepower for long enough to frighten most owners into slowing down, but only tens of horsepower for hours on end (which might work well for a VTOL craft that could also act as a regular aircraft, assuming that the power wasn't abused).  Presumably "hundreds of horsepower for hours on end" requires modifications at least as expensive as buying a flight-rated aircraft engine of similar power (and I suspect is close to where aircraft just upgrade to turbines).

[Snark]

23 minutes ago, wumpus said:

While mufflers on planes might be unthinkable now, I suspect they were nearly as unthinkable in the days of the model-T (and they had to avoid spooking horses).

Apples and oranges.  Cars can be muffled, airplanes can't.

With a car, the thing that's making the loud noises is buried in the guts of the car.  The only reason an unmuffled car is loud, is that the sound from the noisy engine just conducts out the exhaust pipe to the outside of the car.  Stick some sound-absorbent baffles in the way, and the problem is solved.

An airplane can't do that.  Sure, you can muffle the engine, if it happens to be piston-driven.  But you can't muffle the propeller, because it's not hidden in the inside of the plane-- and can't be.  The whole point is that it has to be able to grab air and shove it backwards at extremely high speeds, and that's unavoidably loud.  Jet engines have the same problem.  Yes, you can make jet engines quieter-- modern turbojets are far less noisy than they used to be.  But there's a certain minimum level of noise that's unavoidable if you're spewing exhaust behind you at hundreds of miles per hour.

23 minutes ago, wumpus said:

IMPORTANT NOTE: "Drones" need not mean "quadcopter".  Drones hit the public conscious with the Global Hawk, which was fixed wing and certainly not a quadcopter.  Quadcopters are great if you don't car about fuel (you are using lithium batteries charged by main power, and power consumption is trivial).  They just don't scale up.  Anything that needs to carry a passenger needs to rely on aerodynamic lift (at least once you complete takeoff).

Okay, so now you're talking about "everyone has an airplane" instead of "everyone has a helicopter."  And flying at the kind of high speeds that make airplanes practical.

But an airplane can't take off just anywhere.  It needs not only a runway, but a very big cleared flat area around it.  So now you need to do one of the following:

1. Design your vehicle so it can do VTOL and take off anywhere, in addition to being an efficient, quiet horizontal flyer.
2. Restrict your vehicle to takeoff/landing at airstrips, and require it to be a practical mode of ground transportation as well.

Both of those strike me as being tall orders.  Building a vehicle that's simultaneously really good at two completely different transportation modes is really hard, because they tend to end up being crappy at both of them.  Well designed ground-transportation vehicles are going to be ungainly in the air.  Well-designed airplanes are clumsy and bulky on the ground.  VTOL craft are dangerous, complex, prone to mechanical failure, and expensive.

There's a reason not everybody can own a helicopter or a Harrier.  These things are expensive.  The march of technology can eliminate the piloting requirement, I'm sure, given a decade or two-- the things will fly themselves.  But even if I don't have to be a trained helicopter or airplane pilot... I'm not going to be able to afford one in my lifetime.  None of the factors that make those things stupidly expensive are likely to improve any time soon.

23 minutes ago, wumpus said:

Complexity:  A VTOL aircraft capable of maintaining flight via aerodynamic lift sounds like a recipe for disaster.  Certainly the Osprey (the only high volume example I can think of) is most famous for crashing and killing marines.

Not only does the Osprey have a dubious safety record... it's also STUPEFYINGLY LOUD.  I don't mean annoyingly noisy.  I mean jaw-droppingly, gob-smackingly loud.

I happened to be on vacation last year in a place that happened to be a mile or so from an airstrip, and an Osprey went by a couple of times, I assume on some sort of training maneuvers.  It was really cool, I'd never had a chance to see one before.  But jiminy cricket, that thing made a racket.  We were staying in a rental cottage, and the way that I knew about the aircraft was that there was this thunderous reverberating WHOPWHOPWHOPWHOP roar that was so earth-shattering that it literally shook the house and rattled the dishes on the shelves.  I ran outside just in time to see what on earth kind of aircraft could make such a joyful noise.

It was super cool, yes.    My immediate thought was "...now there's a Kerbal aircraft!"  The most incredible flying contraption I've ever personally witnessed, and I'm glad I had a chance to see it in flight a couple of times.

But I sure as heck wouldn't want one of those things flying anywhere near where I live, on a regular basis!

 

[RainDreamer]

Can something like this scale up for passenger transport?

 

Surely they should take less energy to lift. Just kinda worried about helium cost.

[wumpus]

3 hours ago, Snark said:

1. Design your vehicle so it can do VTOL and take off anywhere, in addition to being an efficient, quiet horizontal flyer.
2. Restrict your vehicle to takeoff/landing at airstrips, and require it to be a practical mode of ground transportation as well

In a nutshell, that is why we don't have a (long distance) flying car.  Your other arguments upthread explain why we don't have local flying cars either.  I wonder if Google (and similar Silicon Valley companies) is doing any research into this type of thing, although "airplane replacement for the googlebus" could probably be handled by the same aircraft that handle regional airlines (although building communities around STOL runways might make sense for this type of thing).

I suspect that any vehicle that meets all the criteria above (less noise, there will always be noise) will rely on multiple untested ideas (such as my freely rotating engine idea).  A single untested idea is usually enough to sink most startups, and this will rely on several, which if they don't all work almost exactly as imagined will cause the thing to fail miserably.  Don't hold your breath for a flying car [PS: this is typically the value of "idea men", to provide things that can sink a company and put people out of work.  Look up what Seymour Cray had to say about being a "pioneer", and then look up what happened when he decided to pioneer GaAs].

[Van Disaster]

Energy density: while we're running out of oil, we really ought to be looking at biodiesel...
Clean energy: anyone totalled up all the radioactive output from nuclear power ( including 3 mile Island/Chernobyl/Fukishima and other smaller spills ) vs that of coal fired powerstations, over the years?

You could probably make a pretty quiet aircraft propulsion device, but it would either be *big*, or inefficient ( surrounding a higher velocity airflow by a much slower one, rather like a scaled up version of how an airliner turbofan works ), or likely big and inefficient.

Over here in the UK there was some work on VTOL commuter aircraft in the 50s - junked as soon as people realised quite how stupefyingly loud it would be.

[Snark]

2 minutes ago, wumpus said:

I suspect that any vehicle that meets all the criteria above (less noise, there will always be noise) will rely on multiple untested ideas (such as my freely rotating engine idea).  A single untested idea is usually enough to sink most startups, and this will rely on several, which if they don't all work almost exactly as imagined will cause the thing to fail miserably.

Added to which is this fundamental problem:  It's not enough that it works.  It has to not only work, but be better than the alternatives.

Simply getting it to work at all would be hard enough... but why is it even needed in the first place?  Mass transit can get better.  Self-driving cars can get better and become ubiquitous.  Data connectivity and telepresence can get better, to the point that you can do more things from wherever you happen to be, without needing to go anywhere.  All of those sound far more plausible to me than flying-passenger-vehicles-for-everyone.  If you come up with a safe, effective flying car, but it costs $100,000... when someone can do practically everything they need from home, or get to most places they need to via quick and effective mass transit or robot surface vehicle, cheaply... that's going to flop economically, even if it's technically brilliant.

That's what I keep bumping up against:  a convincing use case, beyond just "'coz it's cool".  Why is it needed?  And needed so badly that the need can't be more easily met, cheaper and sooner, in some other way?  What exactly is the problem that it's trying to solve?

[wumpus]

3 minutes ago, Snark said:

That's what I keep bumping up against:  a convincing use case, beyond just "'coz it's cool".  Why is it needed?  And needed so badly that the need can't be more easily met, cheaper and sooner, in some other way?  What exactly is the problem that it's trying to solve?

Travel time, mostly while commuting (much harder) or for more irregular trips.  I've heard pilots describe private planes as a "time machine" that gets them there wildly faster (presumably without TSA waits).  The other thing that it enlarges the "places I can easily go" by several multiples (largely because increasing linear velocity increases the square of the area available, assuming you aren't on a thin island or something).

Do people only buy cars instead of bicycles because sometimes it rains?