Why you have (probably) already bought your last car • Hacker News Board

Re: Why you have (probably) already bought your last car

#31

Post by kbob » Fri, Oct 12, 2018, 8:49 PM UTC

jarfil wrote: post #18

lukev wrote: post #6

So frustrating to me that otherwise smart people keep buying into this narrative, including software developers and tech people who should know better. Here's the actual status quo: after a decade of research into autonomous cars specifically (not to mention the decades of AI and systems research before that), we are barely at the point where a car can function safely with Level 2 autonomy, in good conditions. These…

> following verbal or gestured instructions from a police officer or construction worker. If they don't broadcast it with a valid signature, just ignore them, they're not authorized to give any instructions. > turn the road system into a closed system You can turn it into a "closed enough" system, with every vehicle having a radio locator, and everything else being treated as an unknown obstacle... that someone could…

You've never encountered a citizen flagging down traffic because of an obstruction just past a blind hill or curve?

Re: Why you have (probably) already bought your last car

#32

Post by FabHK » Sat, Oct 13, 2018, 9:21 AM UTC

vidarh wrote: post #23

Carpetsmoker wrote: post #11

Earlier quoted context omitted.

Flying cars will always be less efficient (and thus, more expensive) than driving cars due to the physics of it. I wouldn't hold my breath on flying cars replacing driving cars, just as airplanes haven't replaced trains.

> Flying cars will always be less efficient (and thus, more expensive) than driving cars due to the physics of it. As it stands, for cars, the typical energy use is 3k-4k BTU per passenger mile. Commercial airliners use 2k-3k BTU per passenger mile. Of course those get their efficiency from packing more passengers in. But the point being that a statement like the above only makes sense when comparing comparable vehic…

Yes. The Uber Elevare white paper looks at this issue, and the stylised numbers are:

Car: 1 mile/kWh

Flying car: 2 mile/kWh

Electric car: 3 mile/kWh

(Electric engines are much more efficient than combustion engines.)

So, it’s not too bad, plus ground based vehicles (according to the same study) have to drive on average 1.4 miles for 1 mile distance “as the crow flies”.

However, the numbers above are for fixed wing flight, as far as I can tell. Drone-like hovering flight is less efficient.

Still, I think that’s not the main problem. Regulation, battery specific energy, ATC are bigger hurdles.

https://www.uber.com/elevate.pdf/

Re: Why you have (probably) already bought your last car

#33

Post by vidarh » Sat, Oct 13, 2018, 3:45 PM UTC

taneq wrote: post #27

vidarh wrote: post #24

Earlier quoted context omitted.

> You'd have to use a very loose concept of “comparable” for such claims to be plausible There are actual flying prototypes that have gotten at least within a factor of two of electric cars, depending on respective passenger loads. How they'll come out with production models remains to be seen, and also depends greatly on average passenger counts. People tend to overestimate how much energy flight takes - consider th…

> There are actual flying prototypes that have gotten at least within a factor of two of electric cars Linky? > People tend to overestimate how much energy flight takes But underestimate how much energy convenient VTOL takes.

> Linky?

This is one of the easiest accessible ones: https://www.theatlantic.com/sponsored/thomson-reuters-why-20...

> During a 62-mile stretch of its historic flight, the plane used about 25 kilowatts of electricity for a total energy cost of just over $3, according to its pilot, Klaus Ohlmann. In all, the e-Genius consumed just a fifth of the energy of a typical, fuel-powered two-seater airplane.

..

I can't share the rest I have unfortunately, as while the information itself is public (I believe the source is a study by Deloitte), the document I have also contains information that is not, and I don't have a publicly available reference for the source. I'll see if I can find one.

> But underestimate how much energy convenient VTOL takes.

I don't think so. E.g. Lilium uses VTOL, but the wings (holding the electric engines) starts tilting as quickly is possible to start taking advantage of ground-effect, as everyone is of course aware that VTOL is expensive. While the power they need for that short period of time is higher than ideal, it still ends up being a negligible portion of total power consumption other than for extremely short hops.

Re: Why you have (probably) already bought your last car

#34

Post by lucianf » Sat, Oct 13, 2018, 8:42 PM UTC

rambojazz wrote: post #20

justinator wrote: post #8

Honestly, I bought my last car a decade ago. Cars aren't that great for a lot of reasons (my stress level, my city's livability, the environment), and getting rid of the idea of car ownership was one of those huge life decisions that I made that I've never, ever regretted. I don't use car sharing services - that whole industry is toxic for the drivers, I sometimes take public transportation, and every few years, I ta…

But where do you live?

Read the article in his profile, you'll find your answer in 10 secs. And yeah, with that profile, in that location, I take his point. But not everybody is that lucky :)