gomijacogeo

It might not be nanoseconds, but something that's a power of 2 number of nanoseconds going into an appropriately small container seems likely. For example, a 62.5MHz counter going into 53 bits breaks at the same limit. Why 53 bits? That's where things start to get weird with IEEE doubles - adding 1 no longer fits into the mantissa and the number doesn't change. So maybe someone was doing a bit of fp math to figure out the time or schedule a next event? Anyway, very likely some kind of clock math that wrapped or saturated and broke a fundamental assumption.

I go for thrash metal, with earplugs then over the ear headphones turned up enough to get through the earplugs at a comfortable volume. That blocks any exterior sound, is complex enough that I don't get bored, but doesn't have anything hook-y enough that it pulls my attention away from the task.

The plane should have also been uncertifiable as MCAS lacked sufficient redundancy in air data or computing for so much control authority. It's not clear whether this was deliberately concealed by Boeing or if they had just lost the institutional memory to know that this solution was inherently unsafe.

My impression is this is a technique of the 2nd tier energy companies (e.g. https://www.isds.bilaterals.org/vattenfall-vs-germany-i-coal...).

Companies like BP, Total, etc operate more like nation-states and have other tools available.

I'd still call them "Big Energy" however.

Reeve Collins interviewed Monday morning on CNBC. I won't editorialize and just leave it as a data point for others to interpret. https://www.youtube.com/watch?v=3GsMPMXGzAg

1. How much additional energy does it take to pulverize the rock? 2. What about the effect the rock will have on soil pH? 3. What about leached salts and heavy metals?

I think GregKH complained to the university previously and then, when presented with continuing bad/bad-faith patches, decided to blow up their world very publicly.

There does appear to be a static analysis tool.

https://www-users.cs.umn.edu/~kjlu/papers/eecatch.pdf?fbclid...

Still, given that he is 4+ years into a PhD (after a Masters), and has published on this topic before, his first deflection is "We are not experts in the linux kernel" seems disingenuous - kinda like "Hey guys, I'm not malicious, just not good at my job."

Personally, I think their data points should include "...and we had to explain ourselves to the FBI."

Similarly, I was on a highway and saw what looked like a crumpled up brown paper bag in the center of my lane and, rather than make the large maneuver of going around (I had passengers and didn't want to jostle them), I chose to straddle it. Welp, turns out it was a brown rock that had fallen onto the roadway. It managed to clear my oil pan (yay!), but didn't clear the floorboard and rotated longwise and propelled a bottle that was in a grocery bag on the floor into the face of one of my passengers.

Your description is a little terse - are people apprehensive because of: 1) tales of his living at the office and off-hours outbursts, or 2) problematic interactions directly with other employees.

If the latter, you likely should act to separate him from the other employees even though this will likely increase the odds of a bad outcome for him - the needs of the many and all that.

If it's the former, it sounds like unstructured time alone might be his trigger (or, he could just need to 'pop off' for X hours a day regardless of environment). If it is unstructured alone time, it might be possible to put enough structure into his life that he's a lot more stable. Getting him evaluated and maybe set up in some sort of halfway house might be a good longer-term solution.

But it's probably going to be rough and depend a lot on how much you want to invest in this person. He sounds like he's likely schizophrenic and it's usually a roller coaster ride; you can have months of relative stability and then things go off the rails, there are outbursts, police are called, housing goes away, they go back to living rough, and then maybe things settle down and they can climb back up the ladder a bit until the next time or until they die. My biological father's life was like that (I was adopted at birth and didn't meet that side or learn about him until long after he was dead).

Anyway... Yes, he might be a threat. Have a plan; have several plans. Especially have mental health crisis numbers handy and try to avoid police unless there's an imminent threat to human life. Check with your lawyer and insurance about how liable you are with him living there. Try to gently walk him towards mental health resources and other support structures. Maybe work out some sort of buddy system where there's rotating 'Jake duty' to touch base with him once or twice an evening to make sure he's ok. But it's a lot, and this is free advice from the internet, so handle it accordingly.

Though 2.9MeV isn't "cold"; it's around ~3e10 Kelvin.

Looks like other people are onto the same thing - alignment.

Especially if this is threaded code, what's probably happened is something (likely with some sort of locking primitive) that fit on one cache-line, now straddles two. The reverse is also possible where two items were landing on different cache lines and are now creating a false sharing problem.

It's likely a global and likely in the .bss (which comes immediately after .data, which is why it has alignment troubles when static strings change). It's usually pretty easy to binary search your way to the problematic module and variable.

The thing is 1829 didn't crash, the pilots got an alert, figured out the problem, took manual control, and flew the plane. Defense in layers.

It would be ideal to use different technologies for the AoA sensors to help minimize common-mode failures. Integration and crosschecking against other systems (IMU, radar altimiter, DGPS, an open-loop model of the plane based on engine settings and control surface positions, etc) could give the pilots and flight envelope protection systems a better understanding of their situation. Also, the signature of a failed/frozen vane-type AoA sensor is pretty obvious and I'm surprised the software doesn't take that into account.

Good writeup on LH-1829: http://avherald.com/h?article=47d74074

It depends on what the flight characteristics of the Max8 really are - something I've not seen a good writeup on. If the plane really can get away from pilots, then you're likely right (i.e. it really needs a proper flight envelope protection system - and the Max8 is dead). If it's just that the plane flies differently from other 737's, then 2 + subtype training is probably sufficient.

As I understand it, a little bit of everything was done to make up for the shortfall:

1. Spare capacity was used. This makes scheduling tighter and maintenance costs go up.

2. New routes and extra flights that were going to be added to the schedule, weren't.

3. Planes that likely would have gotten parked rather than go through another C/D check instead got the overhaul and are still flying.

4. Carriers that were trying to consolidate types, still fly whatever they were trying to get rid of (or have brought them back into service).

5. Carriers leased planes and probably brought some parked planes back online.

Airlines were lucky in that there weren't that many Max8's in service yet (which also speaks to how unsafe they were to rack up 2 crashes so early), so the grounding didn't eliminate that much capacity as delay planned growth and retirement of airframes.

There is also more spare capacity than you might expect because the fleets are sized for peak operations - thanksgiving, christmas, etc. The rest of the year, the extra capacity allows them to get by with fewer active maintenance people (peak demand vs average demand).

Similarly, there are probably more parked planes than you expect. Again, they are usually up against a C/D check and that check will only get done if it looks like that airframe can earn back the couple $million that the overhaul would cost. The engines usually stay in general circulation and again, smooth out the peak/average maintenance demand.

Not quite. I don't think you all realize how stupendously expensive certifying a new type is. Boeing and the airlines wouldn't be prepared to absorb the extra costs just to have a slightly more efficient 737 at the other end of it.

- MCAS needs to die. I doubt I could have written a subsystem that tries harder to kill you if I tried. Everything about that hack is grossly negligent and possibly criminal.

- Both AoA sensors need to go to both computers.

- All planes get AoA indicators.

- All planes get pitch trim indicators.

- Any kind of MCAS2 should just be an alarm rather than moving control surfaces on its own. If the Max8 diverges too quickly for a human to handle, then Boeing is (and should be) well and truly fucked.

- Regulatory agencies need to have a streamlined 'subtype' certification that recognizes when 99% of the plane is the same and only review the differences. All this MCAS bullshit was to sneak in under a too-strict type certification system in the first place.

Older, yes. Generally not less safe (and certainly safer than the Max8 right now). Usually more expensive - less fuel-efficient engines, maybe up against C/D maintenance checks, maybe less efficient cabin layout, etc.

I preferred this to the Sobel book. More academic, but a lot more technical detail.

The Quest for Longitude: The Proceedings of the Longitude Symposium Harvard University, Cambridge, Massachusetts November 4-6, 1993 Hardcover – November, 1996 by William J. H. Andrewes http://www.amazon.com/The-Quest-Longitude-Proceedings-Massac...

This is not a well-written article and is in a style that is almost impossible to scan.

tl;dr:

1. Richard, the perpetual fuck-up and fame whore. 2. The balloon-boy saga. 3. The balloon-boy aftermath, and legal consequences. 4. Richard whines that his felony conviction prevented him from striking it rich on Shark Tank and tries to turn his kids into a heavy metal version of Hanson. Fails, of course. 5. Later, the author gets access to the wife's case file through her lawyer and finds contemporaneous notes she wrote detailing the planning of the balloon-boy hoax. 6. When confronted with this evidence, Richard needs a few days to process. 7. When Richard finally contacts back, the wife all of a sudden breaks down and confesses the notes were a lie made after the fact to protect the family - Richard is simultaneously shocked at the betrayal and urging her to speak up so the reporter can hear her. 8. Reporter concludes Richard is still full of shit and coaxed the wife into claiming the notes aren't valid.

Agreed! A-pillars have gotten extremely thick over the last 10 or so years to accommodate airbags and the increased rake angle of the windshield brings the pillar much closer to the eye. In my vehicles (2008 & 2018), the left pillar blocks the destination of a left turn (intersections or twisty mountain roads) and the right pillar at intersections block traffic and pedestrians from the right. I bob and weave to try and compensate, but it's definitely more work.

Not that it likely matters now, but the brother sounds like a high-functioning schizophrenic - super-bright kid morphing into an increasingly erratic and alienated adult. Especially without any hallucinations, it's tough to diagnose and looks like a mix of depression, mania, OCD, etc. There's the flight-of-ideas component that frequently allows for great creativity, but frustration as the world can't keep up with their changing visions and priorities. They also tend to be narrative-builders - nothing just happens, everything has a cause, often malignant, byzantine, and vast. Because they always feel 'on' and 'deliberate' everything else must be functioning that way too, so everything is a personal attack. They increasingly can't work with others and try to work as brilliant loners or establish themselves as the visionary leader.

I guess it's ok to update the abort() documentation now.

It does neglect that one overarching design goal was to not be encumbered by any IP. That means you have to pick your solutions exclusively from expired patents and, no, you don't get to be clever and come up with new things along the way because, again, you risk one of the behemoths raining hellfire down on you.

You appear to be making a straw man argument that the planes are safe by claiming to refute the 'sudden-unavoidable-death machines' argument which no one is making.

The probability of a total loss of an aircraft is basically proportional to either its flight hours or number of takeoffs and landings (which are (handwave) correlated (unless you are Aloha Airlines)). A fleet of thousands of planes (especially a 'mature' design), flying thousands of hours per year, in service for decades should have very few losses due to fundamental design issues. It would be nice to say it should be <1, but the reality is the stars sometimes align and several weaknesses conspire to make a fatal event. With MCAS, the 737 Max 8 was already at a rate of 2 events in less than a year with a fleet that was a tiny fraction (<6%) of its ultimate fleet size.

Assuming nothing else changed, at full fleet size, that would be over 30 losses a year, or well over 1000 losses over the fleet's lifetime. They misengineered the system by at least 3 orders of magnitude. This is, at the very least, profound professional and managerial negligence. I'm not not yet convinced it's not also criminal. At the very least, all management who touched this subsystem or were part of the no-new-training-at-any-cost push should have already been shown the door up to and including the CEO.

And yes, things _are_ being done and they are adding 'nines' to the reliability as quickly as they can, but again, they are starting from a subsystem that kills everybody on board every 800,000 flight hours or so.

They appear to be dishonest with the public (and perhaps themselves) about how much risk is eliminated with each change and, similarly, appear to not be factoring in that some of these changes introduce other risks and failure modes.

What we have here is a giant fucking mess and a management organization that fosters no confidence in its ability to navigate itself out of it. In the end, I do expect Boeing to somehow glue-gun 3 more 9's of reliability onto this airframe and stop bleeding valuation, but it won't be pretty and it probably won't be fast.

He also wrote a nifty article back in '81 about calculating e to 118,000 decimal places.

https://downloads.reactivemicro.com/Users/Grant_Stockley/App...

No. He crashed into Monterey Bay. He likely ran one tank dry then sent the plane into a dive while he tried to move the fuel selector that was located over and behind his shoulder.

https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?E...

There is a very (very!) small chance that there are isolated biomes that split from life's tree before what we call the last universal common ancestor (LUCA) and are still plugging along. But it's pretty much impossible that some sister-metabolism from the pre-DNA days could just 'struggle along' side-by-side what we consider 'biology'. When something out-competes another by factors of 1000x or 1000000x, extinction is the only outcome. It's not like elephants and ants finding different niches for billions of years; we're talking about systems of molecules where most of the building blocks are at most a dozen or two atoms and most of the feedstocks are less than 5 (CH4, NH2, O2, H2S, CO, CO2, etc). What's this poor, struggling cousin that we outcompete by a factor of a million going to eat that we can't eat better? Similarly, how does it adapt and evolve against its peers when 999999/1000000 interactions aren't against peers but against us and our self-contained, portable, self-replicating, weaponized Krebs cycle machines?

Some possible alternatives are covered here: https://en.wikipedia.org/wiki/Nucleic_acid_analogue

And I agree that RNA and DNA are pretty good molecules and probably close to some notion of 'optimal'. The ribosome, however, is big and complicated and there are probably millions of different ways something like that could have come about and that would affect the 3-base codon, protein structures, etc.

Also, look at the contortions DNA has to go through to copy what's called the "lagging strand". Clearly duplicating double-stranded DNA did not come early or easily; it's pretty obvious a system bolted on top of some other, older system. https://en.wikipedia.org/wiki/DNA_replication#Lagging_strand

That's what I was trying to say; I'm in no way a panspermia fan. I was responding primarily to the line "perhaps DNA(+RNA) is the only molecule with the right properties to act as genetic material" with the notion that it was probably more special because it was first rather than something intrinsic about the DNA->RNA->ribosome system that made it inevitable. If we could roll the clock back 4.mumble billion years, we'd probably still get life that had a separation between code and structure, but what that code was and what that structure looked like might have been pretty different.