Larry Page is pouring millions into flying cars • Hacker News Board

Re: Larry Page is pouring millions into flying cars

#171

Post by [deleted] » Sat, Dec 31, 2016, 2:35 AM UTC

nickparker wrote: post #157

danbruc wrote: post #31

Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…

Surprisingly, they don't actually need to be all that inefficient. The rolling resistance of a typical car is 0.01 to 0.015 [1], so the effective lift/drag ratio of a car's suspension is about 70 to 100, for just the wheels themselves. Missing from this number are the parasitic losses of all other unsprung mass, aerodynamic drag, and the costs incurred by traveling along roads which are neither level nor straight rou…

[deleted]

Re: Larry Page is pouring millions into flying cars

#172

Post by nrjdhsbsid » Sat, Dec 31, 2016, 2:36 AM UTC

azinman2 wrote: post #98

bootload wrote: post #87

Earlier quoted context omitted.

"Not much to run into up there :)" Birds, hills, turbulence.

Ya. Having just taken a 6 personal commercial plane in stormy, windy weather I'm glad I had two professional pilots driving. It was absolutely terrifying, and I can't imagine your ordinary person feeling comfortable with it. I couldn't wait to get off the plane ASAP and thought we might crash on landing.

Honestly the plane was likely flying itself 90+% of the time. The computers are much better and giving a smooth ride in turbulance.

For fun take a lot at the outer trim tabs when flying in rough skies. The computer adjusts them like 20 times a second to keep the wings stable, kinda cool to see

Re: Larry Page is pouring millions into flying cars

#173

Post by raquo » Sat, Dec 31, 2016, 2:40 AM UTC

nickparker wrote: post #157

danbruc wrote: post #31

Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…

Surprisingly, they don't actually need to be all that inefficient. The rolling resistance of a typical car is 0.01 to 0.015 [1], so the effective lift/drag ratio of a car's suspension is about 70 to 100, for just the wheels themselves. Missing from this number are the parasitic losses of all other unsprung mass, aerodynamic drag, and the costs incurred by traveling along roads which are neither level nor straight rou…

I don't think L/D of more than 10 is realistic for a compact VTOL aircraft even in cruise mode, and then there's the vertical take off and landing component that will cause further inefficiency especially on short trips. But at the same time I don't think it matters that much.

Re: Larry Page is pouring millions into flying cars

#174

Post by overcast » Sat, Dec 31, 2016, 3:15 AM UTC

Spooky23 wrote: post #160

overcast wrote: post #149

Earlier quoted context omitted.

I'm going to infer you're talking about drones. There is a quantum leap difference between self flying military robots, and ones that carry humans around safely during rush hour crowds.

What would someone say in 1996 about a form of cruise control that functions like an airplane shipping today in a Tesla? What would the average person say about a self-driving cab that is currently being piloted by Uber at that time? I'm honestly surprised about the downvoting and snark here. There are Air Force officers sitting in trailers in Nevada right now controlling swarms of semi-autonomous drones, performance…

Remote controlled aircraft are not even in the same ballpark as autonomous aircraft that pick up humans, and drop them off at school/work/home. No one is arguing that this won't be common place someday, but that is a distant future. Self driving cabs are natural a iteration of an existing mode of transportation. Going from manual land cars, to automated flying cars is not even close.

Re: Larry Page is pouring millions into flying cars

#175

Post by aurizon » Sat, Dec 31, 2016, 3:22 AM UTC

Translation:- Larry Page is spending millions of his personal wealth - which he is entitled to do - into a development quest to develop personal dual-use road/aircraft. This will never become economic, although is has been shown many times to be doable, with numerous products developed. None survived the economic screen, let alone the FAA screen. Let us see why:- Ever see a traffic jam? lines of 1000's of cars stopped or going slowly in a wave pattern. - Yes - we see them all the time. Can you see, in your mind's eye an aerial traffic jam, with 1000's of airplanes halted in mid air for a clear path? No. We have never seen them, and we never will, until we invent sky=hooks to hang them on, or a workable anti-gravity system(which may well be impossible).

That said, the planes will have to keep moving a little above stall speed. Can you imagine the air traffic control nightmare of these 1000's of carplanes?

So these are enough to defeat the mass aspect. They may well be viable in Australia, our back with large vistas of flat land and little weather on which 10,000 or more landing strips can be built. Well, we have that now in Australia, but we use airplanes to go from place to place over longer distances and we use cars/trucks for local use. ALl this said, Larry will make his plane, he may sell a few to the idle rich, but they will never become commonplace.

Re: Larry Page is pouring millions into flying cars

#176

Post by crispytx » Sat, Dec 31, 2016, 3:29 AM UTC

These companies are trying to produce something that already exists: The Ultralight Aircraft. Ultralights are cheap, require little training, and no licensing to operate. HOWEVER, they're @#$%ing slow, and aren't practical as a means of transportation because you can get places faster in car.

Re: Larry Page is pouring millions into flying cars

#177

Post by disposablezero » Sat, Dec 31, 2016, 3:34 AM UTC

These will only be toys, and here's why: fuel efficiency (or lack thereof) per passenger. Good luck getting over 2 MPG considering having to haul around bits to meet both road and aircraft regs, fuel and passenger. Plus, do we really want to rehash the already decidedly terrible prospects of making average distracted/intoxicated/uncoordinated people into pilots? Give up lusting over Peter Thiel's science fiction pipedreams and move onto solving real problems like breaking dependence on fossil fuels or sequestering greenhouse gases.

Re: Larry Page is pouring millions into flying cars

#178

Post by gthtjtkt » Sat, Dec 31, 2016, 3:42 AM UTC

danbruc wrote: post #31

Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…

Have you ever heard of a little thing called traffic?

Or something called a "speed limit"?

Can't believe this is the top comment on HN. Reddit? Sure, but I expect better here...

Re: Larry Page is pouring millions into flying cars

#179

Post by personjerry » Sat, Dec 31, 2016, 3:48 AM UTC

gthtjtkt wrote: post #178

danbruc wrote: post #31

Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…

Have you ever heard of a little thing called traffic? Or something called a "speed limit"? Can't believe this is the top comment on HN. Reddit? Sure, but I expect better here...

Conceivably traffic in the air would still be a problem once we get enough volume, unless we permit cars just fly wherever (huge danger!). Similarly, speed should probably be limited unless we want 200mph cars crashing into a building.

Re: Larry Page is pouring millions into flying cars

#180

Post by evolve2k » Sat, Dec 31, 2016, 3:49 AM UTC

"German says battery technology isn’t quite there yet. He predicts the energy density of batteries will need to approximately double for small electric airplanes to really take off."