Syonyk (u/Syonyk) - Readit News

Syonyk commented on WWI's 'Dazzle' Camouflage Seemed Effective Due to Unexpected Optical Trick gizmodo.com/wwis-famous-d... · Posted by u/ilamont

rx_tx · 5 months ago

H.I. Sutton did a great video [1] about it that also explains how it was beneficial due to the way enemy submarines had to estimate speed and heading and could get fooled.

[1]: https://www.youtube.com/watch?v=Kw7vq_YD6JM

Syonyk · 5 months ago

When you're trying to hit something moving 20kt, with something moving 30-35kt, from a few thousand yards, it doesn't take much error in estimating speed, heading, or distance, to make them miss. It's honestly more remarkable that they hit at all in those conditions, even with a "spread" (shooting several along slightly different headings hoping one or two will hit).

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

CamperBob2 · 5 months ago

Sometimes things are much simpler than they seem at first. You set a nonvolatile flag at startup time: badShutdown=true. Prior to shutting down normally, you clear the flag. Then, if the flag is ever found to be set at startup time, you can assume that a crash occurred.

Whether the crash was really due to the battery can be inferred from the battery's age. If the battery is relatively new or is otherwise determined to be OK, don't issue this particular warning. If it's within, say, 90% of the expected service life, then the warning makes sense.

In any event, logic similar to the above was employed at some point to determine when to degrade the phone's performance. That is the point where the warning should have been issued. There are no valid excuses for not doing so.

Syonyk · 5 months ago

So, no, you've not worked with batteries, battery management systems, or anything of the sort.

Determining battery health is hard.

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

CamperBob2 · 5 months ago

There was no need for anyone to guess what was happening when their phone crashed, and there was no need for any default behavior at all. Every time I let my battery SoC go below a certain percentage -- 5% or 10% -- a message pops up asking if I'd like to switch to low-power mode to extend the remaining charge. I appreciate that. Nobody ever objected to that. No lawsuits were filed, no outrage was farmed on Facebook, no hit pieces were published by Bloomberg. So why in the world didn't Apple do something similar following a crash?

The dialog box practically writes itself. "Sorry! Your iPhone has just recovered from an oopsie-poopsie caused by a tired battery. Please choose an option: <Continue operating normally for as long as possible> <Reduce performance to extend battery life> <Schedule an appointment at your nearest Genius Bar to install a new battery (and check out the new iPhones!)>"

It's utterly inexplicable the way they handled this. Someone should have been fired. But then we say that a lot about Apple around here, and it never seems to happen.

Syonyk · 5 months ago

I'm guessing you've not dealt with power electronics and batteries terribly much.

Depending on what limit has been hit, it's quite likely there is no way to log the cause of the error. Low voltage protection circuitry on most batteries doesn't have a status line. It's never supposed to trigger except in exceptional cases, and it just cuts power. All you know is that the power disappeared suddenly, and you've rebooted. Telling the difference between that and assorted other hardware faults, especially if you never designed the hardware to look for it, is really difficult.

You can certainly design a system that will latch the cause of the shutdown in the battery management IC - but you can't really add this in after the fact.

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

behnamoh · 5 months ago

> The number of people using their phones in the hot tub, or in the sauna, astounds me on a regular basis. I can't imagine doing that.

and the number of people who desperately look for a way to replace their batteries or upgrade to a new model just because their phone battery degraded is quite saddening.

Syonyk · 5 months ago

I've suggested to a range of people that if their only complaint is runtime, and the phone is a few years old, getting someone to replace the battery is far cheaper than a new phone. It's a novel concept, and I'm quite unsure if people just don't know if that's a thing, or if that's the socially accepted excuse to spend a lot of money on a new phone.

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

behnamoh · 5 months ago

no one asked for water resistance, but literally everyone said "we want replaceable batteries and don't care about phone thinness either", but Apple doesn't care.

Syonyk · 5 months ago

I'm pretty sure that a lot of people are very happy with water resistance in exchange for having to do a bit more work to replace a battery (that they don't actually replace).

The number of people using their phones in the hot tub, or in the sauna, astounds me on a regular basis. I can't imagine doing that. But, with modern devices being genuinely "drop them in the pool" grade waterproof, neither does it seem likely to be a problem.

I'll agree on thinness, though. The number of phones in massive, chunky cases says "A lot of people don't care about thin."

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

brokenmachine · 5 months ago

Imagine a world with replaceable batteries.

Syonyk · 5 months ago

Imagine the tradeoffs, though.

A "user-serviceable battery," by requirements, is going to be a hard shell plastic sort of thing - which means a decent fraction of the "total battery space" is a protective layer, not active cell components - so some significantly reduced capacity compared to having a "non-replaceable" battery ("slightly more difficult to replace"). You also end up having to devote space to whatever mechanisms keep the rear shell in place, and may have a harder time waterproofing it as a result (which seems to be standard anymore - the number of people I see at the gym using their phones in the hot tub or sauna is boggling).

Batteries, under light use of phones not kept in pockets, last a very long time - 3-5 years isn't unreasonable, and many will last longer. Batteries, under heavy use of a phone kept in a pocket and run hard, will still typically last 1.5-2 years. So in exchange for "slightly more inconvenience less than annually," you get a good bit more capacity and runtime.

Apple, in general, hasn't made their batteries nonsensically hard to replace. They've used the "pull tab sticky" sort of thing for some while, which is far nicer than "glue the whole thing down," and their newer devices are using some sort of electrically released magic (apply 9V to the adhesive, battery pops out).

There's no such thing as a free lunch.

Syonyk commented on Firmware update bricks HP printers, makes them unable to use HP cartridges arstechnica.com/gadgets/2... · Posted by u/speckx

brokenmachine · 5 months ago

Apple admitted purposefully slowing down older devices with updates.

They said it was to prolong battery life.

Syonyk · 5 months ago

It was more to prevent unexpected shutdowns. Which, I'll add, were a problem with Android devices at the time, and the Nexus 5, in particular, had three battery OEMs, one of which would only last a year before being unable to run the device in high demand situations (say, "taking a picture with the flash").

As lithium batteries age, their internal resistance goes up - you can model a battery as a voltage source and a series resistor accurately enough. Over time, that resistance goes up, which means, for a given current, you end up with less voltage "at the output." Most power supplies will compensate by pulling more current to provide the needed power, which will drop the voltage more until you slam into the low voltage protection circuitry that cuts power.

The Nexus 5s are the ones I'm most familiar with, and they absolutely had this problem with one of the battery OEMs (the only way to tell which OEM you had was to pull the battery out, they were labeled on the back). The typical symptom was, "The phone shuts down when you try to take a picture," because camera modules are power hungry, the CPU was spinning hard to keep up with rendering the view from the camera (and possibly doing some pre/post frame capture to find the best frame, I don't recall when that showed up), and the flash pulls a LOT of current, very briefly. So everything would simply shut down when you hit the button to take the picture.

Apple decided to attempt to limit this problem, and they locked out the highest tiers of CPU performance (which are the most power hungry), if the device was having brownout issues. It's a reasonable enough strategy. Where they failed (IMO) was in not alerting the users that it was happening, or that it was a battery health issue. The later iterations of it, where it tracks battery health, and will tell you if your battery is going bad and needs replacement, are what they should have rolled out, and didn't. My guess is that they didn't think it was going to be a major issue for many devices, so it was just a CYA sort of thing that would prevent shutdowns. Unfortunately, that also happened right around the same time that US carriers started dropping the "New phone every 2 years on contract!" thing, and so the iPhones of that era started being used rather substantially longer than the previously-expected 2 years, and, Apple, so drama for clicks.

Had they just gone about telling users, "Hey, it looks like your battery is getting weak, would you like to schedule a replacement? Otherwise, we've limited performance slightly to prevent shutdowns." - I think it would have been fine. And they did settle on that eventually. It just took a few iterations.

Syonyk commented on Regulatory gridlock in the U.S. risks losing the drone arms race seanobannon.substack.com/... · Posted by u/seanobannon

moduspol · 6 months ago

Yep. It boggles my mind that we still do aircraft flyovers at big football games. Those should be drones doing coordinated light shows--even in heavy winds, rain, and unfavorable conditions. Just to show that we've mastered it, and that we can do it easily even when there are no stakes.

My genuine hope is that secretly we actually are really good with drones and just strategically have decided not to broadcast it, but I don't think that's the way forward. It needs to be known that we've absolutely mastered them.

You know, kind of like the Chinese have done with their drone shows at the Olympics and similar events.

Syonyk · 6 months ago

> My genuine hope is that secretly we actually are really good with drones and just strategically have decided not to broadcast it...

What would you call the Reapers and such? The US has a massive fleet of large, armed drones, remotely operated, and quite a few are capable of being armed.

https://en.wikipedia.org/wiki/Unmanned_aerial_vehicles_in_th...

It's different from the consumer/small commercial drones being talked about here, but the US Military is pretty darn good at UAVs.

Syonyk commented on US authorities can see more than ever, with Big Tech as their eyes proton.me/blog/big-tech-d... · Posted by u/jethronethro

Syonyk · 6 months ago

The book from a year or two ago, "Means of Control," by Tau, goes into some pretty good detail on the data collection and sales from just the adtech firms - where the entire ecosystem seems to be, "You can't use our data for anything but advertising... wink wink", and everyone knows exactly who is bidding on ads, and never winning any, just to slurp up location data and sell it. Or the "companies that don't sell the government." Also, they don't vet any clients beyond "The credit card is good."

> And because giants like Meta, Google, and Apple must collect as much of your personal data as possible, there’s little they can do to protect your privacy.

I quite disagree with the "must" there. They choose to collect as much data as possible, because that's their business model.

And the good news is, it's fairly easy to opt out of quite a lot of that.

Turn location services off, turn your phone off when moving about, and pay cash without "personal tracking cards" associated with you. Just about everywhere has [local area code] 867-5309 registered, if you care.

Syonyk commented on After Moss Landing Power Plant reignites, officials brace for more flare-ups sfgate.com/bayarea/articl... · Posted by u/speckx

rtkwe · 6 months ago

We really need to figure out a way to reliably extinguish Lithium fires or at least have a way and a place to transport them to so they can be contained until we can be sure they're not going to spontaneously reignite like these did. It's kind of wild to me that they seem to have just left the burnt batteries in place.

Syonyk · 6 months ago

They're an absolute pain in the rear to deal with, because they're self igniting, and it propagates between cells.

Your typical lithium 18650 - vape cell, old laptop cell, whatever you know it as (18mm diameter, 65mm length, cylindrical), has a high end capacity of around 3500mAh - so 3.5Ah (amp-hours - so will take an hour to drain at 3.5 amps, 3.5 hours to drain at 1 amp, handwave goes here). At 3.7V nominal, that's around 13 Wh (watt-hours, a measure of energy capacity).

As a first order handwave, when a cell runs away and burns off all the materials in it (electrolyte, plastic separators, etc), you'll get about twice the energy out of the cell as the electrical capacity - so, ballpark, 25Wh for a fully charged 18650 running away. Except, it doesn't run away in an hour. It runs away in about 30 seconds, so doing the math on that, you end up with about 3000 watts for those 30 seconds. That, meanwhile, can heat nearby cells up enough to cause them to enter thermal runaway, and the whole pack will just go, until cooled sufficiently.

"Dumping a lot of water on the pack" will, generally, cool it down enough to stop this. Assuming you can get the water where it needs to be, and in something like a shipping container battery, that's far from given.

At this point, you've got a damaged battery, in unknown condition, with none of the existing current paths able to be relied on, and probably new current paths that may or may not exist yet (water, metal, corrosion, and those paths are often high resistance and slow to form, which creates a lot of heat). It's not really safe to disassemble it or work on it until things have been discharged, because if the pack has energy left in it, it's prone to do exactly what this article talks about - reignite, later, inconveniently.

As far as disassembling it, would you go work in a few megawatt-hours of energy, in unknown configuration, with the state of the safety systems unknown, in a charred environment of unknown toxins (what you get out of a runaway is far from predictable, beyond "generally unfriendly to humans")?

It sounds silly, but if the pack is confined and the fire isn't going to spread to other packs nearby (which is why they tend to be quite spread out), the safest thing to do really is to let it burn to completion. At that point, if it's actually burned out, there's no energy left in the cells to do anything terribly nasty, and you've burned off most of the electrolyte and such.

Anyway, the right answer is lithium iron phosphate for grid scale energy storage, but even those can catch fire if water gets in the wrong places, and they will, with enough prodding, burn.