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Never trust a system that seems to be working

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Re: Never trust a system that seems to be working

#241

Post by Gordonjcp »

Unklejoe wrote: post #90
electroly wrote: post #43

This is why 4-20 mA is a common signaling standard in industrial automation. 4 mA means zero and 20 mA means one. 0 mA means broken transmitter !

Another example is how garage door opener trip-beams work (the sensors that detect if something is in the way before lowering the door). The transmitter and receiver are wired in parallel and connected to a power supply through a series resistor. When the receiver receives the signal from the transmitter, it pulls the supply voltage down, which then causes the transmitter to stop transmitting, which then causes the r…

Gas central heating boilers use something similar to control the gas solenoid - the solenoid is fed through a biggish capacitor, which has a diode and a capacitor to "smooth" the pulses from the microcontroller. If the microcontroller output latches itself on, the capacitor charges fully, there are no more pulses, and the solenoid drops out.

Re: Never trust a system that seems to be working

#242

Post by conradfr »

fknorangesite wrote: post #136
city17 wrote: post #108

Earlier quoted context omitted.

Was thinking the same. Once you exceed like 5 tweets in a thread, it becomes a small article and you would've been better off just writing an article in the first place. If you check the thread reader below you can see just how unstructured and incoherent it is compared with a simple article.

If you're genuinely curious: > I have ADHD: it makes writing blogs hard but Twitter easy. So it gets quickly tiring that every time I'm posted there [to HN] that the comments immediately go "why isn't this a blog? Twitter is a bad site for this kind of writing and I hate it blarg" https://twitter.com/foone/status/1440695857699962893 This exact comment of yours is a prime example of why foone hates it when their tweet…

How does that make sense? You write the same amount of text in the end.

Re: Never trust a system that seems to be working

#243

Post by Gordonjcp »

bombcar wrote: post #127
acdha wrote: post #120

Earlier quoted context omitted.

That’s a great example of how you always have to design for a context.

Yeah, any design is going to be various trade-offs, and you have to understand them (and how they may relate to your mission) when determining what to do and what would be a bad decision. For example, cars have "fail open" brakes but have independent cylinders so that it is relatively hard to have all four wheels fail at the same time (older cars had single master cylinders) - and one of the tradeoffs is that people…

Pretty much every car made since the 1980s has had dual-circuit brakes with usually one front and one rear wheel cylinder on each circuit. Volvo being Volvo took it further with their 2-series cars in the 1970s and 1980s, where the front discs had four-pot calipers configured as two sets of two-pot calipers. Each braking circuit had one half of each front caliper and one rear caliper, so in the event of one half of the brakes failing it would still stop in a straight line.

You can use engine braking in automatic vehicles too, by simply changing to a lower gear.

Re: Never trust a system that seems to be working

#244

Post by djhn »

wongarsu wrote: post #180
andirk wrote: post #169

Earlier quoted context omitted.

Best choices to pick on captcha are not what you think is pictured but what you think most people think is pictured.

Since about 60% of the visitors of most English-speaking websites are American, I assume that requires finding the American answer. But that requires me to jump not just a language barrier but also a cultural barrier to figure out nuances like "what constitutes a traffic light? Do pedestrian lights count? Do the poles and cables count, or just the light-emitting part?" "What constitutes a street sign" "Is a Mecedes S…

Buses are bad, but I feel trucks are even worse. Or actually vehicles in general. What does a Venn diagram of cars and trucks look like? Are Vespas and trikes motorcycles?

Re: Never trust a system that seems to be working

#245

Post by ranger207 »

unsupp0rted wrote: post #237
CaliforniaKarl wrote: post #226

Earlier quoted context omitted.

In this case, there’s no need to imagine. Their latest Tweet has the answer.

It seems to be about misgendering on HN? I never understood why it's such a big deal. When people guess wrong about my gender, ethnicity, preferred spoken language, etc, I correct them. I guess if they were to argue with me about the correction and insist their guess was right, that would get old fast and I'd be as frustrated as foone.

It happens much more frequently by people with malicious intent to them. All you have to do is say once that misgendering is annoying and them trolls will latch on and do it intentionally to harm you

Re: Never trust a system that seems to be working

#246

Post by ranger207 »

conradfr wrote: post #242
fknorangesite wrote: post #136

Earlier quoted context omitted.

If you're genuinely curious: > I have ADHD: it makes writing blogs hard but Twitter easy. So it gets quickly tiring that every time I'm posted there [to HN] that the comments immediately go "why isn't this a blog? Twitter is a bad site for this kind of writing and I hate it blarg" https://twitter.com/foone/status/1440695857699962893 This exact comment of yours is a prime example of why foone hates it when their tweet…

How does that make sense? You write the same amount of text in the end.

The dopamine hit from click the send button can help overcome the ADHD tendency to wander off task. Plus, even if you have half an essay posted to Twitter and still get bored, it's much more difficult to just leave it halfway finished than to leave an unposted blog post in your drafts. And besides that, I'm really not sure why people get so upset at people putting content into the world. Wasn't the point of the internet to make it easier for people to share their knowledge with the world?

Re: Never trust a system that seems to be working

#247

Post by smugkot »

dudeinjapan wrote: post #119
ben_w wrote: post #96

Reminds me of Jurassic Park (book, I think?); nobody realised that dinosaurs were loose and breeding, because the system was doing: if dinosaurs and nobody anticipated dinosaurs > expected

"Life, uh, finds a way." Dr. Ian Malcolm anticipated it, but the park science lackeys dismissed his idea.

If I remember correctly, Malcom did nothing but harp endlessly about how the park was doomed to failure due to various vague non-sequiturs.

All we know is that he predicted fence integrity would fail somehow. We don't know what else he predicted, maybe he just got that one right by chance. We don't know if Hammond changed the park after the paper to invalidate Malcom's reasons for predicting fence integrity failure; if he had done this, Malcom would be wrong despite having predicted fence integrity failure.

We sent people to the fucking Moon _and_ brought them back home. I'll be damned if humans can't solve Jurassic Park.

Re: Never trust a system that seems to be working

#248

Post by tbodt »

jstanley wrote: post #231
CaliforniaKarl wrote: post #226

Earlier quoted context omitted.

In this case, there’s no need to imagine. Their latest Tweet has the answer.

I can only see 1 comment in this thread that uses "he" to refer to a person, and it refers to a different person, so I'm not sure I follow.

There are plenty, but you may have to turn on showdead and scroll to the bottom and uncollapse to see them.

Re: Never trust a system that seems to be working

#249

Post by manicennui »

Laremere wrote: post #197
1-more wrote: post #171

Earlier quoted context omitted.

One thing I hated about working with Go. POSTed JSON bodies missing a field could not be distinguished from those where that field pointed was present and pointed to the empty value for that (an empty array or string or something). This may be entirely work-around-able and simply a failure of how that job worked, but it was a whole thing .

In this case, instead of, say, an int, you could have the field be a pointer to an int.

And now you've traded one problem for another.

Re: Never trust a system that seems to be working

#250

Post by bentcorner »

unsupp0rted wrote: post #237
CaliforniaKarl wrote: post #226

Earlier quoted context omitted.

In this case, there’s no need to imagine. Their latest Tweet has the answer.

It seems to be about misgendering on HN? I never understood why it's such a big deal. When people guess wrong about my gender, ethnicity, preferred spoken language, etc, I correct them. I guess if they were to argue with me about the correction and insist their guess was right, that would get old fast and I'd be as frustrated as foone.

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