This is really meat-dependent, ironically - the biggest thing we could do is cut consumption of steak and other prime cuts of beef, since ground beef is made out of what's left after those expensive, sought-after cuts are taken. I would guess that eliminating ground beef consumption doesn't really get us anywhere for the environment.
I've said this elsewhere in the thread, but stabilizing a dynamically unstable system is half of the reason why control theory remains an active research area instead of a mathematical backwater; this kind of set up is extremely common for aerospace systems. Software is hard to get right - which is why aerospace software has traditionally faced much higher bars for verification than 'traditional' software (and is much more expensive as a result!) The same is true of hardware, which I think many HN commentators forget; the cost of a bolt or connector that is aerospace-grade is typically many times that of a conventional or automotive-grade part, due mostly to extensive testing+verification required for safety.
Most of the scenarios you're describing are dealt with in a few ways:
1. Building systems with sufficient margin to account for this kind of uncertainty; even with passively stable aircraft, these margins exist. Feedback control typically increases these margins.
2. Extensive verification under a wide range of input conditions; this is more challenging (how can you enumerate every possible failure condition?), but usually boils down to some kind of Monte-Carlo sampling or worst-case analysis when those cases can be identified. Here's [0] a neat paper that does this in a more sample-efficient way.
A caveat here is that the modern FAA is very different than the FAA of even 20 years ago. In response to decades of stagnant funding, 'the beast' is fundamentally unable to fill the same regulatory role it was intended to do - to all of our detriment [0].
Aerospace controls engineer here - while the airframe might not be passively stable (as is common for civilian aircraft), dynamically unstable aircraft have been stabilized with control software since the 70s [0]. If you've flown on an MD-11, you've flown on an 'aerodynamically flawed' aircraft. Most real systems are dynamically unstable without some kind of controller (implying software) in the loop.
Ah - I didn't say Boeing's ability to write and test that control software was particularly good (in fact, I think their current track record says exactly the opposite.) I just hate when non-domain experts make judgements about things being 'fundamentally flawed.'
Insufficiently tested and documented? Sure. Bad UI/UX? Most definitely. Irredeemable 'because of aerodynamics' according to some private pilot that flew a 737 once in sim? Absolutely not.
But yes. MCAS was put in place due to concerns over aero. If that was just to avoid the need for extra pilot training then it should have been scrapped since new training will be required now anyway. But since great effort has been made to fix MCAS we can conclude that the root problem is aerodynamic.
Can aerodynamic issues be compensated for with software? Sure. I need to read up on the final hardware/software/instruction solution before passing Judgement.
You're completely ignoring that flying the 737 MAX without MCAS is not an automatic death sentence. Meanwhile a malfunctioning MCAS is actually an automatic death sentence.
The big flaws are in the software, not in the hardware. So stop focusing on that.
It’s “atypical” because it’s a 30+ year old superseded model and there are more efficient designs available. KLM, a flag carrier, was flying them up until just a few years ago. If it’s certified for carrying passengers, it’s certified. There are no special concessions made to airworthiness regulations for aircraft that sell few in number.
The MD-11 has been certified for air transport since it was introduced, was flying in revenue service until 2014, and as far as I know, that certification has never been revoked.
I don't think the flight safety record of the MD-11 bears that out[0] - most crashes of significance were either cargo flights (which are much more prone to dynamical issues than passenger flights) or flights in conditions that exceeded design specs (landing in typhoons). It sounds like most airlines sold it because it missed range/fuel burn targets, not because of safety issues.
My Dad was a frequent business traveller in the 1980s and 90's and I remember him commenting on the MD-11 and saying that he hated them because they were noisy and had lot of vibrations at the back from the center engine.
He said that was the the reason airlines switched to using them as cargo planes.
No, it is just another form of minority rule. Why should 7% of the country get to set its environmental policy in exchange for less voice in the national government?
As a corollary - how many people already spread inaccurate or misleading video clips, sound bites, etc without this technology, and how many already refuse to believe real ones produced by the 'lying news media?' I think the hysteria is completely misplaced, and the extremely polarized media landscape is itself to blame.
I like this idea, and I think the research has backed it for decades - I wrote a letter to my Senator, Hillary Clinton, in support of later school starts back in middle school that cited such work. I think it hasn't happened for two reasons:
1. School is childcare for a lot of people; secondary schools let out early so older siblings can take care of younger ones.
2. As COVID has shown - it's difficult to manage multiple hybrid schedules and cohorts in an equitable way, especially if you're not expanding the number of teachers (which most districts can't due to budget constraints)
This is a little US-centric, but I suspect it applies broadly to the rest of the West at least.
It's been stated elsewhere in this thread, but there really are a lot of practical, well-understood engineering issues with Elon's proposals that he refuses to admit or deal with. Here's a somewhat humorous review of his claims / what's wrong with them and how they stack up to actual civil engineering projects:
I agree with most of this, except for the unexpected rapid-response examples you list - I would expect an autonomous collision-avoidance system to react faster than a human being when faced with a deer in the road or someone running a light (otherwise - it's not a very good collision avoidance system!)
It can react faster to an object. But, under at least some circumstances, a human might recognize potentially questionable road conditions in a way that an autonomous vehicle would not. (Of course, presumably the human could also tell the autonomous vehicle to slow down.) And I've definitely seen animals at the side of the road looking they may be inclined to run out.
The rest of the world is rife with small, rural towns that nevertheless have great public transit systems, or at least ones that are more effective than what we see in the US. The major difference is that these places are willing to invest in the public sphere, and they're by and large willing to permit construction that is not car-centric (i.e., no parking minima to subsidize drivers).
