3 ms·

Agreed. In a perfect world, wire-based systems should be cheaper and more reliable. But as a software engineer, I can tell you that current software development

Agreed. In a perfect world, wire-based systems should be cheaper and more reliable. But as a software engineer, I can tell you that current software development practices do not produce software that is reliable enough to entrust it with your life. And when corners get cut, the software development lifecycle tends to be an easy target.

wat10000 2y ago
There are plenty of places where we entrust software with our lives. We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS, and that could easily kill you if it activates at the wrong time in the wrong way. Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats). Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug. So could any device with a lithium-ion battery. And of course numerous airliners are fly by wire and they remain the safest form of travel out there. Now, I certainly wouldn't trust anything written with a typical app development process with my life, but it's not the only way to do things. I'm totally on board with being pessimistic about most software reliability, but it's not realistic to say that no software can be reliable enough to trust with your life.
- ToucanLoucan 2y ago
  > We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS The software is limited to being able to flutter pressure going to the actuators within the calipers. Basically it de-pressurizes/re-pressurizes the actuator very quickly. ABS cannot engage or disengage the brakes in totality, that is exclusively done via the pedal. (In the systems I've worked on anyway) > Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats). Rather famously, early Prius models had issues where the drive-by-wire throttle would become stuck on due to a software malfunction. > Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug. Um... how? I could see this if something suddenly let go quite violently in the power supply maybe, but that's far likelier to happen when the unit is in use, not when it's sitting idle. And more to the point even if the computer inside had a bug that caused the magnetron to engage at full whack with nothing in the microwave... I mean it probably wouldn't be good for the microwave, but I don't see how that equals a fire. > So could any device with a lithium-ion battery. That one's true though. But good electronics are monitoring all the voltages across all the lithium cells involved, along with temperature, and many have perma-kill switches if anything looks too off for this exact reason. > And of course numerous airliners are fly by wire and they remain the safest form of travel out there. They're also absolutely drenched in aeronautics gear that is both managing the aircraft and verifying that the redundant systems are ready to take over, reporting the same data, and that all is well. And aircraft regularly get grounded if anything even seems like it might be off with it.
  - wat10000 2y ago
    What is checking "if anything looks too off"? Pretty sure there's software involved there. And yes, I know airliners have all sorts of stringent standards. But the fact remains that many of them do rely on software to keep the occupants alive. Making software reliable enough to bet your life on it is hard, but not so hard that we should consider it to be an unattainable goal.
    - ToucanLoucan 2y ago
      > What is checking "if anything looks too off"? Pretty sure there's software involved there. It's not just software: is software running on redundant systems that can check one another for consistency and performance. You're never going to see that level of engineering in an automobile, cars would be far too expensive if they were as complex, electrically, as an aircraft. Aircraft are only getting away with it because, as you correctly observed, if the computers malfunctioned, they're going to fall out of the sky and kill all your passengers. If your car malfunctions, it just won't move/will stop moving.
      - wat10000 2y ago
        That “it anything looks too off” was battery management systems. I don’t think they have redundant systems. In any case, the sentences I was replying to was: > But as a software engineer, I can tell you that current software development practices do not produce software that is reliable enough to entrust it with your life. All I’m saying is that this is wrong and we do routinely trust software with our lives. If you want to explain how it’s done and why it’s done that way, go for it, but it sounds like you think you’re arguing against it.

wat10000 2y ago

There are plenty of places where we entrust software with our lives. We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS, and that could easily kill you if it activates at the wrong time in the wrong way. Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats). Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug. So could any device with a lithium-ion battery. And of course numerous airliners are fly by wire and they remain the safest form of travel out there. Now, I certainly wouldn't trust anything written with a typical app development process with my life, but it's not the only way to do things. I'm totally on board with being pessimistic about most software reliability, but it's not realistic to say that no software can be reliable enough to trust with your life.

ToucanLoucan 2y ago
> We don't yet have brake by wire, but we certainly have software-controlled brake actuation on any car with ABS The software is limited to being able to flutter pressure going to the actuators within the calipers. Basically it de-pressurizes/re-pressurizes the actuator very quickly. ABS cannot engage or disengage the brakes in totality, that is exclusively done via the pedal. (In the systems I've worked on anyway) > Uncommanded acceleration is another possibility that might have actually killed people (or maybe it was just floor mats). Rather famously, early Prius models had issues where the drive-by-wire throttle would become stuck on due to a software malfunction. > Outside of cars, your microwave could burn your house down in the middle of the night with the right sort of software bug. Um... how? I could see this if something suddenly let go quite violently in the power supply maybe, but that's far likelier to happen when the unit is in use, not when it's sitting idle. And more to the point even if the computer inside had a bug that caused the magnetron to engage at full whack with nothing in the microwave... I mean it probably wouldn't be good for the microwave, but I don't see how that equals a fire. > So could any device with a lithium-ion battery. That one's true though. But good electronics are monitoring all the voltages across all the lithium cells involved, along with temperature, and many have perma-kill switches if anything looks too off for this exact reason. > And of course numerous airliners are fly by wire and they remain the safest form of travel out there. They're also absolutely drenched in aeronautics gear that is both managing the aircraft and verifying that the redundant systems are ready to take over, reporting the same data, and that all is well. And aircraft regularly get grounded if anything even seems like it might be off with it.
- wat10000 2y ago
  What is checking "if anything looks too off"? Pretty sure there's software involved there. And yes, I know airliners have all sorts of stringent standards. But the fact remains that many of them do rely on software to keep the occupants alive. Making software reliable enough to bet your life on it is hard, but not so hard that we should consider it to be an unattainable goal.
  - ToucanLoucan 2y ago
    > What is checking "if anything looks too off"? Pretty sure there's software involved there. It's not just software: is software running on redundant systems that can check one another for consistency and performance. You're never going to see that level of engineering in an automobile, cars would be far too expensive if they were as complex, electrically, as an aircraft. Aircraft are only getting away with it because, as you correctly observed, if the computers malfunctioned, they're going to fall out of the sky and kill all your passengers. If your car malfunctions, it just won't move/will stop moving.
    - wat10000 2y ago
      That “it anything looks too off” was battery management systems. I don’t think they have redundant systems. In any case, the sentences I was replying to was: > But as a software engineer, I can tell you that current software development practices do not produce software that is reliable enough to entrust it with your life. All I’m saying is that this is wrong and we do routinely trust software with our lives. If you want to explain how it’s done and why it’s done that way, go for it, but it sounds like you think you’re arguing against it.