Ask Slashdot: After We're Gone, the Last Electrical Device Still Working? 403
Leomania writes: After watching a post-apocalyptic Sci-Fi short on YouTube (there are quite a few) and then having our robot vacuum take off and start working the room, I just wondered what would be the last electric/electronic device still functioning if humans were suddenly gone. I don't mean sitting there with no power but would work if the power came back on; rather, something continuously powered, doing the task it was designed for. Are we talking a few years, decades, or far longer?
A.I.? (Score:3)
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Exactly what I was going to say... the AI that exterminates mankind will keep working indefinitely.
Re:A.I.? (Score:4, Interesting)
There has been a ton of progress towards 'true' AI over the last 40 years, it just has not managed to produce one. Progress != Success, esp on such difficult problems.
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Re:A.I.? (Score:5, Interesting)
I don't know - a lot of current weak AI may end up being sub-systems for a strong AI - so in that sense we may well be getting closer. The problem is we have no real idea what strong AI might actually entail, implementation wise, and so have essentially no idea what if any progress we're making in that direction. At the very least we've found a great many strategies that don't work, which is in fact it's own kind of progress.
Honestly though I'm happy with the current state of affairs - weak AI may be able to get us into a lot of trouble (market crashes due to HFT algorithms anyone?) but it's nothing compared to what a strong AI would be capable of.
Re: A.I.? (Score:3)
satellites (Score:5, Insightful)
Probably satellites would last the longest, with maybe Pioneer or Voyager probes for however the RT batteries last.
Re:satellites (Score:5, Funny)
A Nokia 3310 will outlast them all.
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Only if it's sitting on its charger... It only had a week's worth of battery. Which is massive by today's standards, but still.
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God I miss the days of good cellphones. My Nokia N82 was epic in battery life. Back when Nokia made the absolute best cellphones in the solar system.
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Re:satellites (Score:5, Informative)
The Volkswagen Beetle from the Woody Allen movie, "Sleeper"
http://www.tin.org/bin/man.cgi... [tin.org]
More realistically, some chemical batteries, such as good lead-acid batteries in cool, dry climates will retain a slight charge for years. But they all have a notable self-discharge rate of at least a few percent a month. The notable exception among battery technologies seems to be this:
http://en.wikipedia.org/wiki/O... [wikipedia.org]
That device has been running off its battery, at an extremely low rate, since 1840. The bell is much softer now, but it shows no signs of failing.
Re:satellites (Score:4, Informative)
The Voyager RTGs are decaying, NASA expects output power to drop below the point where it can keep a single instrument going around 2025.
The Pioneers are already long past the point where they can't send a strong enough signal to be detected.
The latest nuclear power plants for the US Navy have been designed to run without refueling for the life of the ship. That's 50 years for aircraft carriers, so the USS Gerald R Ford (CVN 78) is capable of functioning until 2065. Now I don't know how stable a nuclear power plant is when left on its own, but potentially this'll live much longer than the Voyagers.
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One should be very wary of the distinction between "run without refueling" and "run without regular maintenance". Even assuming that the reactor's fuel would last, the ancillary equipment associated with the reactor's operation (coolant pumps and such) and electricity generation (steam turbines) certainly wouldn't be expected to operate unattended and unmaintained for months, let alone years.
That said, the fifty-year planned lifespan of the Nimitz-class includes, if I'm not mistaken, a mid-life refuellin
Re:satellites (Score:5, Insightful)
One should be very wary of the distinction between "run without refueling" and "run without regular maintenance". Even assuming that the reactor's fuel would last, the ancillary equipment associated with the reactor's operation (coolant pumps and such) and electricity generation (steam turbines) certainly wouldn't be expected to operate unattended and unmaintained for months, let alone years.
That said, the fifty-year planned lifespan of the Nimitz-class includes, if I'm not mistaken, a mid-life refuelling and complex overhaul (RCOH). To be fair, the reactor's fuel would likely last longer than the planned 20-25 years if the carrier weren't actively steaming--but I wouldn't trust the other parts to last anywhere near so long.
As a steam turbine engineer, I am fairly confident that, given a well maintained system to start with, the first failure would probably be in a stuck steam control valve. Over time, oxides build up on the valve stem, which would cause it to become stuck at some point. This would probably take 3-6 years. When that happened, the instrumentation control loop (need more steam, open valve, need less steam, close valve) would have a hiccup since it would ask for more or less demand and the valve wouldn't move. Valves stuck-open have historically caused many turbine overspeeds and resulting disasters.
Depending on exactly how the system was set up, the stuck steam valve should trigger the control system to automatically close a different valve, shutting down the plant. However, it is possible that it would result in a large kaboom as the turbine entered overspeed and the turbine blades liberated.
As for the last electrical device operating, my money would be on a solar powered yard light. The quality of those devices is generally terrible but the law of averages suggests some of them have to be on the long tail of a MTBF curve.
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... as the turbine entered overspeed and the turbine blades liberated.
See. It's not just software. Turbine blades want to be free too.
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Running out of mono-propellent probably wouldn't be an issue because satellites simply don't attempt those kind of maneuvers without human input (at least I'm pretty sure), while that would definitely be a problem for LEO and Geostationary craft between those two orbits or are further out don't need regular boosts to stay going. And while reaction wheels do go bad pretty quickly (a decade or so) they aren't necessarily needed for a spacecraft to remain "operational". Sure without them they usually can't c
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Not in Geostationary orbit. They will be there "forever", they may still work for a long time, but eventually debris impact and radiation will kill them.
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Re:satellites (Score:5, Informative)
Either my understanding of orbital mechanics is completely wrong or that is completely incorrect. Geostationary satellites need very regular station keeping otherwise they either fall to Earth or are ejected out into solar orbit. If ejected it could remain operational for a while but if it fell back to earth the results would be obvious.
Your understanding of orbital mechanics is totally wrong. Geostationary satellites do need frequent stationkeeping maneuvers, but that is because the satellite is required to remain in a 30km box. If these maneuvers cease, as would happen with the sudden disappearance of humans, they will start to drift off their stations, eventually collecting in a couple of regions, one over the Indian ocean and the other over the Pacific. (This is due to the earth's slightly uneven gravity). Because of the vastness of space, the probability of them actually running into each other is fairly low.
A geostationary satellite would need almost the same amount of energy to come down as it takes to put it up there, and probably twice as much to escape the earth's gravity well. At the end of life of these satellites, they use the remaining fuel to boost them another 200km or so in altitude, then vent all remaining fuel (so they won't explode if there's a fuel leak), and then blow the electronics to make sure they don't interfere with anything else. They will remain in that graveyard orbit forever.
XKCD answered this (Score:5, Interesting)
A very similar question was in an XKCD "What If?", but only in the printed book version (which has a bunch of extra chapters compared to the blog): "What would be the last artificial light source to glow when all humans were gone".
IIRC, the conclusion was that it would be status LEDs on space probes or radiation glow from buried nuclear waste.
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Gnu Hurd build server??
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IIRC, the conclusion was that it would be status LEDs on space probes or radiation glow from buried nuclear waste.
Why would space probes have status LEDs? Think about it.
Re:XKCD answered this (Score:5, Insightful)
Unit testing before launch?
That would be useless wiring weight (Score:2)
Re:That would be useless wiring weight (Score:5, Informative)
Having spun a number of boards in my career, I can tell you that it is trivial to add an 0402 LED indicator, just as an indication that the 3.3 V logic rail is powered. And because it was easiest (via inertia) to keep it in than to cut it out (even as a do-not-populate instruction to the board house) that little LED stayed in the design, even though in production no one would ever see it.
Given the complexity of most satellites, I would be deeply surprised if there wasn't at least one LED on one of those boards.
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> And because it was easiest (via inertia) to keep it in than to cut it out (even as a do-not-populate
> instruction to the board house) that little LED stayed in the design, even though in production no one
> would ever see it.
And someday down the line, in a situation he never imagined, someone is going to see that LED and be glad it was there. Possibly after its been scrapped, rescued from the scrap heap, and repurposed to replace the fried control in someone's coffee maker....but appreciated none
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"Hot damn, an LED! We can sell this and eat for a month! Too bad we don't have the technology to actually make these anymore...."
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That's kind of an interesting point. Let's say 500 years from now humans have warp drive and can zip between stars. Should the Voyagers be collected* and placed in a museum? Should it be left alone as a historical "site?" One could visit it. Get the sense of what ancient man accomplished, sending this tiny thing so far from home. But that would be lost putting it on display at the Smithsonian.
I argue a "traveling" museum should be built next to Voyager, sharing its journey. School kids could warp in on thei
Re:That would be useless wiring weight (Score:5, Interesting)
We don't design LEDs into our own boards, and we explicitly remove them from COTS boards that we use. Generally speaking the diffusers on LEDs outgas, meaning a) they are depositing materials on your spacecraft surfaces (bad) and b) could result in a shorting risk (also bad). There may be space-grade LEDs that big-space (think Hubble, JWST, Voyagers, etc.) use but I would be surprised. There's simply no need.
"Is it plugged in? Is it turned on? Is it on frequency?" solves about 99% of basic device connection issues. An LED will make one very short portion of that slightly shorter, and then only when testing on the bench, since you can't see it as soon as you box it up. As soon as you can talk to a device, you are able to run a long form functional test on it, exercising every part of the design and ensuring everything is working correctly. If it passes, you're good. If it fails, you pull the unit.
For ground support equipment, yeah sure, throw an LED on every rail and switch output.
A nuclear power plant (and its control room)? (Score:2)
Re:A nuclear power plant (and its control room)? (Score:5, Interesting)
Nope. It would scram when the rest of the electric grid collapsed a few days in. The plant has to constantly output power. When the grid fails, the plant automatically goes into safe mode to avoid tearing apart the turbines. Diesel generators then start up to run the plant until grid power returns but they'd only last as long as the fuel.
Nothing associated with the public electric grid would last long without humans present.
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The nuclear pile still puts out a decent amount of heat after scram, and there are thermocouples down there for emergency power.
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I would recommend reading The World Without Us, which examines what would happen to the relics of our civilization if we, humans, suddenly disappeared (i.e., not extinct via war or disease, but just hypothetically got raptured away). Nuclear power plants don't fare so well. In fact, without human attendants to control them, cleanly power them down, and then decommission the plant several decades later, there is every likelihood that some nuclear plants would
Satellites (Score:4, Insightful)
Solar-powered, geosynched satellites will keep going for a while.
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What about them garden lamps that are solar powered? They charge during the day and give off light at night.
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The contacts will probably be the first to fail, followed by the storage capacitors. The panels are generally overspecced, and fail by degradation, so they'll likely outlive the LEDs. It's kind of depressing that such a simple and solid state device would fail so quickly.
Re:Satellites (Score:4, Insightful)
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Solar powered craft at L1 or L2 can probably go for a few milennia.
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Solar cells will degrade to the point they can't supply keep-alive power to the spacecraft; batteries will degrade to the point they can't sustain the spacecraft through eclipse season; electronics will accumulate more and more total ionizing dose, single event upsets and latchups will become more and more frequent, and things will basically stop working. I don't think anything we've launched will come within an order of magnitude of a millennium.
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Sorry you said L1 and L2; ignore eclipse season comment.
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Even L1 and L2 lunar orbits are not that stable without attention. Solar forces, such as light pressure and solar wind, tend to destabilize them over time and require station keeping, especially as satellites have low mass and large solar panels.
There are other difficulties for satellites. The increased radiation of all types and even magnetic effects from the Van Allen belts can be very hard on circuitry. Adding shielding is very expensive, and over time even the shielding can become slightly radioactive
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Re:Satellites (Score:4, Interesting)
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Re:Satellites (Score:4)
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I'm starting to regret I even said anything.
Welcome to the Internet.
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How about the SOHO satellite? A L1 orbit should stay pretty stable even without any further assistance.
http://sohowww.nascom.nasa.gov... [nasa.gov]
Min
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L1, L2, and L3 are weakly stable; think being at the top of a parabola. It doesn't take much effort to keep yourself there, but you do have to reject orbit perturbations. L4 and L5 on the other hand are actually stable, which is why trojans collect there. Note that there aren't any natural equivalents to trojans at L1, L2, and L3.
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Geostationary satellites collects in orbit at some places quite some distance out, and can be there for a very long time. Moon pull and solar wind may impact them, but it can take a long time before they leave their positions.
Satellites at the Lagrange points are probably going to stick around even longer.
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Solar powered wrist watch... (Score:2)
Re: Solar powered wrist watch... (Score:3)
My Casio is up to year 8 on the original battery. If my corpse fell where there was plenty of sunshine but not so much dirt as to wash up and bury my wrist I could see it going quite some time more. It's good for 200 meters diving, it should handle exposure for a good long time.
WALL-E (Score:5, Funny)
Solar powered parking meters (Score:4, Funny)
1. Solar powered parking meters, obviously. Humans may be all gone, but you still gotta pay for your spot downtown.
But seriously though, these are designed to be robust, and to keep working even if the solar panel gets dirty. I don't see any reason why it would fail at any time.
2. The other one I can think of are (again, solar powered) satellites in higher orbits. But I am not sure how much damage the solar radiation does to those on the long run.
3. Wouldn't it be sad if the last electric device to work is one of those crappy solar powered moving plants (made of plastic)?
One of these: https://www.youtube.com/watch?... [youtube.com]
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"There will come soft rains" (Score:5, Informative)
Ray Bradbury asked the same question in 1950.
http://en.wikipedia.org/wiki/T... [wikipedia.org]
The Cutter
Comment removed (Score:3)
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These puppies are way out there, running on neclear power. No-one to bug them, nothing to break them.
Nothing?
Because there are not millions of objects hurtling through our universe at any given moment, as we sit here and theorize what large object might have wiped out all life on this planet before?
The universe is nothing but one big pinball machine. Luck runs out eventually.
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NASA gives the thermoelectric generators on the Voyagers 10 more years" [nasa.gov].
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Xleggorp and Zullupt have been tagging that thing every time they make the Kessel run in less than 11 parsecs.
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High powered electric heaters (Score:3)
They are just a piece of wire, often embedded in some kind of ceramic. Without power and stored at a place well protected from the enviroment it would likely last for 100,000 years or more.
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I think that the expected lifetime of Ohm's law is roughly the age of the universe.
Easy (Score:2, Funny)
The last electrical device after humanity ends will be the deathray which the aliens used to blast humanity out of existance.
Probably the Oxford Electric Bell (Score:5, Informative)
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Isn't that just powered by the magnet field?
a data collection device in antarctica (Score:5, Interesting)
andrew trigdell told me an amazing story back in 1999 about how he helped install Linux 0.99 on a solar-powered data collection computer in antarctica. Linux 0.99 was known to be highly stable, hence why it was chosen. it has a 56k modem which is enough to get the data back, and to check (very slowly) that it's still operational. so i think anything that's designed for long-term with those kinds of harsh remote and inaccessible conditions in mind, powered off of sustainable independent power, would be a good candidate for a device that would still be functioning even decades later.
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It's design is probably robust for decades, but anything out on the ice that sits still for more than a few years is destined to get buried in snow, solar panels and all.
If humans still exist... A lot of stuff. (Score:2)
Unless.... You expect a targeted strike where the only survivors are liberal art majors. Spin some magnets in some copper wire you get electricity. You can spin it with a water wheel, wind turbine, combustion engine, or steam power.
You reverse the process and you can make a motor. ...
Place some resistance you get heat and light.
This dystopia future just isn't practical unless there is some lead time where science and engineering has been some how removed from our cultures.
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Or worse, Graphic arts majors.
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You might want to re-read it. "After we are gone" in the sense of "no more humans."
Oblig xkcd? (Score:2)
Sounds like a question for Randall's "What If" series.
Fascinating question though. I should imagine one of the voyager probes perhaps, or a solar powered beacon on a hill somewhere. A lot of stuff on Earth is very dependent on regular maintenance so I wouldn't imagine much stuff still working fifty years from the hypothetical extinction event.
Something burried inside mountain (Score:2)
We already know (Score:4, Funny)
It's actually on an adjacent planet rather than Earth, but Opportunity seems like it will just keep going.
xkcd joke [xkcd.com] about it.
My Pink Floyd Pulse Album (Score:2, Funny)
The little LED on my pink Floyd pulse album will still be flashing long after we are all gone.
Ironically? (Score:2)
Ironically?
Given the way things are going, probably the Opportunity Mars Rover...
Probably small static battery powered devices (Score:2)
The Clarendon Electric Bell. (Score:2)
It has been ringing continuously since 1840, and will probably continue for a long time.
Read all about it here: http://www.atlasobscura.com/pl... [atlasobscura.com]
BS question (Score:2)
The power goes out permanently about 15 minutes after human input stops. That is the planning interval in the large electrical grids. No humans results in emergency shutdown of all power-plants a few minutes later and that is it.
Solar (Score:2)
The Oxford Electric Bell (Score:2)
The Wikipedia [slashdot.org] explains:
The Oxford Electric Bell or Clarendon Dry Pile is an experimental electric bell that was set up in 1840 and which has run almost continuously ever since, apart from occasional short interruptions caused by high humidity.
[...] The Oxford Electric Bell does not demonstrate perpetual motion. The bell will eventually stop when the dry piles have distributed their charges equally if the clapper does not wear out first.
RTG of some kind (Score:2)
The power output of RTGs declines over time, but according to Wikipedia Americium-241 has a half-life of 432 years and is an experimental replacement/alternative to Pu-238 RTGs.
Since shielding and weight requirements are a non-factor for terrestrial RTGs, it wouldn't surprise me if there was some secret bunker someplace with a huge (1-2kW) RTG in place as a kind of emergency power source capable of powering a control system or something to bring up other power systems.
Uncle D (Score:2)
Solar powered emergency phones? (Score:2)
Kind of mundane, but they're built to get installed in the middle of nowhere and keep working.
Solar calculators (Score:3)
With moderate use, those things last forever.
The Other end (Score:2)
Solar powered electric fence charger (Score:2)
A solar powered electric fence charger is designed for neglect. The fence itself will be useless, weeds will ground it fairly quickly, and anybody who maintains them knows a fence won't last a year unmaintained, but the solar powered charger will keep ticking as long as the battery lasts, and will probably keep trying even after the battery fails. The cheap little solar powered yard lights also should keep working for quite a while, at least the ones that aren't DOA when they are purchased.
But all devices
fish, plankton, seagreens ... (Score:2)
and protein from the sea.
I am 'box' !
Not anything from Apple (Score:2)
RTGs in lighthouses (Score:4, Interesting)
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As opposed to a non-nuclear nuke?
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Help Stamp Out Care Bears! (Score:5, Funny)
Topic: Ask Slashdot: After We're Gone, the Last Electrical Device Still Working?
Reply Subject: Who cares?
Response: I don't care. I think that it isn't a interisting problem.
Analysis: Looks like this dim bulb has gone out.
Tally: Currently at 999 Points of Light [wikipedia.org]
Who: A Child Left Behind
What: Passionate declaration of indifference.
When: 42 years after men last walked on the Moon.
Where: March For Apathy 2015 [cancelled]
Why: Dissonant aggressive demotivational pathos.
What: 's the use.
How: Did we get here?
Further Reading on this Topic: Failed Slashdot submission,
Breakthrough: Manned Space Travel Achieved Using 40-Year Old Technology [slashdot.org]
TheRealHocusLocus writes
"Paul Rosenberg has uncovered some surprising new evidence that manned space travel is not only possible, it has actually been achieved using decades-old technology. [theburningplatform.com] Some 40 years in the making, a tale too amazing to remain untold. With a few quaint photographs he asks, could we build this? The answer is no. Or is it? It is uplifting to read that "Productive humans have been delegated to mute observance as their hard-earned surplus is syphoned off to capital cities, where it is sanctimoniously poured down a sewer of cultured dependencies and endless wars..." for it must take something really compelling to prevent us from reaching the stars, and he has nailed it. This essay makes the case that the headliner of 2052 may well be: Breakthrough: Manned Space Travel Achieved Using 80-Year Old Technology. I can hardly wait! Down with robots. [slashdot.org]"
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The thermoelectric generators on both Voyagers have a finite lifetime. I don't think it's very much longer until they are both inert lumps of metal. 10 years [nasa.gov] according to NASA.
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The atomic clock might be the only thing working after we are gone.
Isotopes will be decaying, but there will be no one and nothing to count the decays. But what ever is the last thing actually running, you can be sure it will be running Windows NT. For more on this and a brief history of the circumstances which brought our modern world to its knees, see my own little parable about technological angst and global catastrophe, The Time Rift of 2100: How We lost the Future [slashdot.org]
Postscript to the story: Internet of Things security concerns! Must. Implement. Granular. Crypto. [slashdot.org]. Yep,
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Rust only happens in the presence of oxygen. and I have seen sealed systems that are flooded with noble gasses that will absolutely stay in like new condition for 10,000 years unless the polymer seal fails massively. oxygen intrusion would be so slow that they would probably still be OK 5000 years after a seal failed.
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No, they are ignoring it because that is what the question specifically tells you NOT to consider.
Here, broken apart by more than just a semi-colon.
"I don't mean sitting there with no power but would work if the power came back on[.]"
"rather, something continuously powered, doing the task it was designed for."
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I wish I had mod points. IRC, Hoover Dam would continue to make power for 50 years after we're gone. The only reason it will stop, is the water intake valves will get too clogged with marine detritus without divers to periodically clean them.