Solar, wind and tidal power are all boondoggles which simply can't provide enough energy to satisfy worldwide demands and aren't reliable enough for distributed grids.
Schemes to put solar farms in the Sahara and pipe all that energy north ignore the burgeoning demands to the south, etc.
The mid-term answer is likely to be Molten Salt Nuclear Reactors - which aren't your grandfather's steam engines with red hot pokers in the boiler that the current water-based systems all are and don't have the safety issues that come with mixing flimsy metal rods holding radionucleides and ultra-hot, ultrapressurised, corrosive water. Steam explosions aren't nearly so scary if they don't come with a radioactive cleanup requirement.
It's not as if emergency air inlet valves can't be fitted along the tunnel.
For added safety they can be positively powered (ie, they "fail to state=open") and small enough that any particular one wedged open won't be enough to overcome the vacuum pumps. Power-off would mean the tube repressurises quickly and evenly (which avoids shock loadings)
Because the tube is under vacuum, emergency access doors are relatively easy, They'd be held shut by air pressure until things equalise. These doors will be needed for maintenance puposes anyway and can be spaced as appropriate (probably every 100-200m)
Tidal/quake movement resistance/accomodation is easy enough. Bridges, roads, railways and pipelines already do this.
The part which has always been the kicker for vac-train designs has been switching issues in order to build a network. Stub switches are safest overall for this kind of design but require large amounts of movement. It's likely that capsules will need to slow down dramatically to accomodate this or else people will end up with major injuries if walking around the cabin.
More railway-like designs could be used, but the pods would need to be guided safely somehow through turnouts, lest they end up smeared over the intersections.
I've mentioned this before and I'll do so again: Shifting people is an inefficient use of rail or vactrains. Freighting systems could be revolutionised by this, but the tubes need to be big enough to accomodate a pod carrying a full-size (40 foot) intermodel shipping container. Smaller aircraft containers exist but they're harder to load, unload and handle due to awkward shapes.
"All capsules have mechanical braking systems and are spaced five minutes apart, automatically triggered in the event of an obstruction. "
For the envisioned capacity, that means you're looking at pods carrying several hundred people (if not a couple of thousand) with their attendant slow loading times.
It's far more likely that you'll use block management to get closer spacing and entrained groups of capsules, quite possibly linking up whilst in motion out of terminii.
Because when the builders (BAE) were asked to quote for converting, they gave a figure slightly higher than building an entire new ship.
Common sense on their part. BAE will provide support services for the F35s and if the UK chose something else they'd lose a lot of income.
Of course that assumes the F35-B will actually make it to service, otherwise HMS Sitting Duck(*) and HMS White Elephant will be remain oversized helicoptor carriers plying the waves for a long time past their intended date.
(*) The UK can't field enough ships to form a carrier escort group, so building the things was mostly pointless. Ballistic antiship missiles are likely to render Aircraft Carriers mostly useless in the next 20 years anyway.
When you have 190MW onhand, a distillation plant (reverse osmosis these days) isn't a big load - your crew needs much more water than the steam system in any case.
The big advantage of electric launchers is not having to route major league plumbing up to the flight deck or have the same risk of a pressure explosion, plus if something goes wrong you can cut a linear launcher instantly. Steam catapaults cannot be stopped no matter what.
"If the organs of most people dying would be available for transplantation, only a small fraction would be needed."
If we can work out how to grow cloned parts in the lab then we don't have the ethical issues of transplants OR having to worry about keeping people on anti-rejection drugs for the rest of their lives.
Foreign donor transplantation is a last resort and it leaves the recipient in need of constant medical care for life. We can do it, but it shoul dbe a stepping stone, not an end in itself.
"The problem was if he put together a team that did know how to design a satellite he never would have managed to do it within the required budget"
People who "know how to build satellites" would never fit what they know how to build into a cubesat even if they were free. Believe me, I've watched them trying.
"They could either fly and fix any remaining problems during the mission, or they could scrub."
This is the essence of flying any space probe where you're a hitchhiker. It's why Beagle didn't quite complete its mission and it's why what was left of the original Solar mission ended up being dug out out of a south american swamp by the french foreign legion (there's a piece of that sitting in a glass case not far from me).
All in all they did well. They'll do better next time and that is the essence of cubesats (learning from your mistakes).
The only thing they really missed out on design-wise was having a hardware watchdog reboot it faster than it would have otherwise done.
I've been building those into remotely deployed systems for 35+ years. The top of a mountain may not be LEO but not having to helicopter out to hit a reset button because you can't drive out through 15-foot deep snowdrifts saves a few thousand dollars the first time you get a lockup.
"I'm baffled as to why we've not as yet built a single robot that can do that and survive in one of these reactors. They've all broken."
Let me know when you have a robot that can handle Hot (60C+) wet (steam and water) acidic (did I mention the water is borated?) environments with lots of sharp edges (broken stuff, jagged metal, etc) and uneven surfaces full of things which just _love_ to snag trailing cables.
Oh, and you're required to pick up what's essentially a powder (uranium and plutonium oxide for the most part) on the floor of the area you're investigating. (Meltdown refers to the zirconium fuel rods melting and the contents spilling out, not the bottom of the containment vessel being breached). That powder and other stuff will get into every sliding or rotating joint you can think of and grit it up.
Uranium and plutonium aren't particularly radioactive. What's cooking off all those wonderful gamma rays and high neutron flux is primarily Caesium - which is a reactive metal even when you don't have radioactive isotopes.
You really are better off leaving it alone for a few half lives and coming back in 35 years when it's safe to work on it.
"nuclear technology is highly dangerous, and utterly filthy (certainly for fission) "
Uranium-based nuclear technology is, on a number of levels - but Coal is several hundred thousand times _more_ dangerous, on a deaths per Terawatt/hr basis and burning coal releases at least as much radioactive material (mostly radium) into the atmosphere each year as several chernobyls, but noone cares about that like noone cares that they're several times more likely to die on the way to the airport than in a plane crash.
There _are_ safer technologies available and the most promising was tested in the 1960s. They _are_ being developed for civil operation - and the good thing is that they'll eat most of that nasty "high level waste" as fuel whilst outputting less than 1% as much as current generation plants do, which will have a dangerous lifespan of ~300 years and then be composed of mostly useful substances. They'll also nail the "helium shortage" pretty much permanently
Fusion power is 50 years away from practicality and a few decades past that for civil operation (it's been like that for the last 60 years). Fission is what we have until then. Carbon is easy but simply too dangerous to continue using.
"- There is no practical way to replace nuclear power plants within the medium term (not even long term)."
Agreed, however there are practical replacements which are somewhat safer.
Mixing high pressure (20-30 bar or more), high temperature (400-600C) borated water (ie, corrosive) and nuclear fuel rods is such a fundamentally bad idea that I'm still surprised anyone allowed it in the first place - or continues to allow it. Even Heath Robinson or Rube Goldberg would be speechless (fuel rods are routinely corroded through, resulting in unavoidable contamination of the cooling loop).
Molten Salt systems are corrosive too, but not as much as the water-loop systems. They're not under high pressure and ready to spray steam containing dissolved radionuclieides everywhere if there's a pinhole, plus they can't go far if they do escape before they freeze solid. MSR systems are really good at being hot, but really bad at making Plutonium for bombs, which is why they were abandoned 40+ years ago.
Nonetheless, nobody died, nobody got even slightly sick (a few minor burns) and apart from the immediate vicinity of the reactors (as in, right up against the containment vessels) the area had lower background radioactivity than the Yorkshire Dales or Denver or downtown Helsinki even before the cleanup crews went in. The dangers of radioactivity are so vastly overblown it's difficult to have a sensible conversation about actual real world risk factors because everyone's terrified of it (yet they think nothing of jumping in an aircraft and flying for hours at an equivalent dose of at least a chest x-ray every hour).
Tepco deserves a major reaming, but that's mostly down to the japanese sense of pride that would prevent them admitting they're out of their depth and asking for outside assistance even if Godzilla was razing Toyko (they actually refused assistance offers). The govt deserves an even bigger reaming for their inept regulatory controls, being too cozily in bed with the power companies and not forcing Tepco to accept outside assistance.
The correct thing to do now is wait 35 years for the caesium compounds to die off then cleanup. That's exactly what's happening at Three Mile Island at the moment. Sending robots in now is a fundamentally bad idea because unless they're left in there they'll track nasty shit back out.
The "highly radioactive" tanks full of water around the plant have about the same levels as you'd find if you dropped a radium watch in an olympic swimming pool and the remaining issue with radioactivity levels has much more to do with the japanese govt having slashed allowable levels by 90% overnight (resulting in fish which was perfectly safe before the accident being dangerously radioactive should you try to sell it now and that's put a lot of people out of business). Whilst you probably wouldn't want to drink from those tanks, it's only slightly more radioactive than seawater and it's safe enough to swim in that I'd feel comfortable doing so (many mineral springs and spas have much higher radioactivity levels, but people are perfectly willing to jump in or "take the waters" those because the radiation is "natural")
"It doesn't have to be fast if the job is one that you can scale up and just buy more robots"
And you only have to teach _one_ robot.
Incidentally the first generation of car painting robots in factories were programmed by the simple expedient of memorising the movements as a human pushed the spray nozzles around. I have no idea if it's still done that way
Car workers didn't complain when robots did the dirty stuff like welding/painting, but they didn't like it when they intruded further on the line (even japanese carmakers got (limited) industrial action on this one). At some point humans will kick back against warehouse robots too, but the reality is that robotising most of these kinds of jobs where safety is important (You'd be surprised how many people get killed by forklifts) has a net benefit.
Robot floor pickers exist in a number of areas already, but the final packing and dispatch tends to be done by humans because the mk1 eyeball can spot damaged goods better than an electronic one when everything's mixed up.
> FWIW, there's even a "church-tax"... in many European countries. here has been a recent trend of people leaving churches in European countries if it allows them to avoid paying these "taxes"
It gets odder than that. In the UK, if you live in a parish then you're liable for costs resulting from the upkeep of the parish church, no matter what your religion (or lack of) is, or if you attend another one somewhere else.
Then again a lot of people identify as "christian" despite never having set foot in a church in their life (The "my parents were so I am" model - this happens with other religions too. I know a bunch of very secular people who say they won't come out as such because it'd upset their muslim or sikh parents)
I don't _want_ recruiters calling/emailing me with vague sniffs of something. If it's more solid than that then sure, but they're paid to find the right person for the job on offer, not to send a bunch of possibles along to interviews. If they're doing that then they're not worth the hassle.
Ditto applies to recruiters who just tick boxes.
Where I work, our experience has almost universally been that what gets sent along by recruiters is the same as (or slightly worse than) the group who see our adverts and apply directly. There's almost no benefit in using them and in most cases they're doing the hopefuls a disservice by talking up their job prospects in order to have more names on their list to offer employers.
"The main reasons for backups (esp. for individuals) are 1) user error, and 2) hardware failure, not acts of god. An on-site NAS protects against those just fine"
It doesn't protect against burglars.
Seriously. We've had several instances at $orkplace of equipment being stolen from staff residences and the backup drives + NAS going too.
Slashdot Mirror
"They will have to commute an hour to work if they want semi-affordable housing"
And they can probably find an equally-well paid job closer to home, so why should they bother?
If outfits can't find staff then the solution is to pay more, not moan about it.
Solar, wind and tidal power are all boondoggles which simply can't provide enough energy to satisfy worldwide demands and aren't reliable enough for distributed grids.
Schemes to put solar farms in the Sahara and pipe all that energy north ignore the burgeoning demands to the south, etc.
The mid-term answer is likely to be Molten Salt Nuclear Reactors - which aren't your grandfather's steam engines with red hot pokers in the boiler that the current water-based systems all are and don't have the safety issues that come with mixing flimsy metal rods holding radionucleides and ultra-hot, ultrapressurised, corrosive water. Steam explosions aren't nearly so scary if they don't come with a radioactive cleanup requirement.
It's not as if emergency air inlet valves can't be fitted along the tunnel.
For added safety they can be positively powered (ie, they "fail to state=open") and small enough that any particular one wedged open won't be enough to overcome the vacuum pumps. Power-off would mean the tube repressurises quickly and evenly (which avoids shock loadings)
Because the tube is under vacuum, emergency access doors are relatively easy, They'd be held shut by air pressure until things equalise. These doors will be needed for maintenance puposes anyway and can be spaced as appropriate (probably every 100-200m)
Tidal/quake movement resistance/accomodation is easy enough. Bridges, roads, railways and pipelines already do this.
The part which has always been the kicker for vac-train designs has been switching issues in order to build a network. Stub switches are safest overall for this kind of design but require large amounts of movement. It's likely that capsules will need to slow down dramatically to accomodate this or else people will end up with major injuries if walking around the cabin.
More railway-like designs could be used, but the pods would need to be guided safely somehow through turnouts, lest they end up smeared over the intersections.
I've mentioned this before and I'll do so again: Shifting people is an inefficient use of rail or vactrains. Freighting systems could be revolutionised by this, but the tubes need to be big enough to accomodate a pod carrying a full-size (40 foot) intermodel shipping container. Smaller aircraft containers exist but they're harder to load, unload and handle due to awkward shapes.
"All capsules have mechanical braking systems and are spaced five minutes apart, automatically triggered in the event of an obstruction. "
For the envisioned capacity, that means you're looking at pods carrying several hundred people (if not a couple of thousand) with their attendant slow loading times.
It's far more likely that you'll use block management to get closer spacing and entrained groups of capsules, quite possibly linking up whilst in motion out of terminii.
A working hyperloop system will need those doors anyway - because the only way of changing tracks is old-school stub switches.
https://en.wikipedia.org/wiki/...
What? You thought Hyperloop would be a single continuous tube from end to end?
"The UK carriers don't have a catapult."
Because when the builders (BAE) were asked to quote for converting, they gave a figure slightly higher than building an entire new ship.
Common sense on their part. BAE will provide support services for the F35s and if the UK chose something else they'd lose a lot of income.
Of course that assumes the F35-B will actually make it to service, otherwise HMS Sitting Duck(*) and HMS White Elephant will be remain oversized helicoptor carriers plying the waves for a long time past their intended date.
(*) The UK can't field enough ships to form a carrier escort group, so building the things was mostly pointless. Ballistic antiship missiles are likely to render Aircraft Carriers mostly useless in the next 20 years anyway.
When you have 190MW onhand, a distillation plant (reverse osmosis these days) isn't a big load - your crew needs much more water than the steam system in any case.
The big advantage of electric launchers is not having to route major league plumbing up to the flight deck or have the same risk of a pressure explosion, plus if something goes wrong you can cut a linear launcher instantly. Steam catapaults cannot be stopped no matter what.
"If the organs of most people dying would be available for transplantation, only a small fraction would be needed."
If we can work out how to grow cloned parts in the lab then we don't have the ethical issues of transplants OR having to worry about keeping people on anti-rejection drugs for the rest of their lives.
Foreign donor transplantation is a last resort and it leaves the recipient in need of constant medical care for life. We can do it, but it shoul dbe a stepping stone, not an end in itself.
"Maybe we should just allow people to buy kidneys"
Hello organlegging.
"The problem was if he put together a team that did know how to design a satellite he never would have managed to do it within the required budget"
People who "know how to build satellites" would never fit what they know how to build into a cubesat even if they were free. Believe me, I've watched them trying.
"They could either fly and fix any remaining problems during the mission, or they could scrub."
This is the essence of flying any space probe where you're a hitchhiker. It's why Beagle didn't quite complete its mission and it's why what was left of the original Solar mission ended up being dug out out of a south american swamp by the french foreign legion (there's a piece of that sitting in a glass case not far from me).
All in all they did well. They'll do better next time and that is the essence of cubesats (learning from your mistakes).
RTOS is not needed, nor is it practical.
The only thing they really missed out on design-wise was having a hardware watchdog reboot it faster than it would have otherwise done.
I've been building those into remotely deployed systems for 35+ years. The top of a mountain may not be LEO but not having to helicopter out to hit a reset button because you can't drive out through 15-foot deep snowdrifts saves a few thousand dollars the first time you get a lockup.
bah: Zirconium fuel rod CLADDING. It's only a few 10ths of a millimeter thick at the best of times.
"I'm baffled as to why we've not as yet built a single robot that can do that and survive in one of these reactors. They've all broken."
Let me know when you have a robot that can handle Hot (60C+) wet (steam and water) acidic (did I mention the water is borated?) environments with lots of sharp edges (broken stuff, jagged metal, etc) and uneven surfaces full of things which just _love_ to snag trailing cables.
Oh, and you're required to pick up what's essentially a powder (uranium and plutonium oxide for the most part) on the floor of the area you're investigating. (Meltdown refers to the zirconium fuel rods melting and the contents spilling out, not the bottom of the containment vessel being breached). That powder and other stuff will get into every sliding or rotating joint you can think of and grit it up.
Uranium and plutonium aren't particularly radioactive. What's cooking off all those wonderful gamma rays and high neutron flux is primarily Caesium - which is a reactive metal even when you don't have radioactive isotopes.
You really are better off leaving it alone for a few half lives and coming back in 35 years when it's safe to work on it.
"nuclear energy is the door which we shouldn't ever have opened but which, once done, we cannot close."
Really? Look up LFTRs sometime.
"nuclear technology is highly dangerous, and utterly filthy (certainly for fission) "
Uranium-based nuclear technology is, on a number of levels - but Coal is several hundred thousand times _more_ dangerous, on a deaths per Terawatt/hr basis and burning coal releases at least as much radioactive material (mostly radium) into the atmosphere each year as several chernobyls, but noone cares about that like noone cares that they're several times more likely to die on the way to the airport than in a plane crash.
There _are_ safer technologies available and the most promising was tested in the 1960s. They _are_ being developed for civil operation - and the good thing is that they'll eat most of that nasty "high level waste" as fuel whilst outputting less than 1% as much as current generation plants do, which will have a dangerous lifespan of ~300 years and then be composed of mostly useful substances. They'll also nail the "helium shortage" pretty much permanently
Fusion power is 50 years away from practicality and a few decades past that for civil operation (it's been like that for the last 60 years). Fission is what we have until then. Carbon is easy but simply too dangerous to continue using.
"- There is no practical way to replace nuclear power plants within the medium term (not even long term)."
Agreed, however there are practical replacements which are somewhat safer.
Mixing high pressure (20-30 bar or more), high temperature (400-600C) borated water (ie, corrosive) and nuclear fuel rods is such a fundamentally bad idea that I'm still surprised anyone allowed it in the first place - or continues to allow it. Even Heath Robinson or Rube Goldberg would be speechless (fuel rods are routinely corroded through, resulting in unavoidable contamination of the cooling loop).
Molten Salt systems are corrosive too, but not as much as the water-loop systems. They're not under high pressure and ready to spray steam containing dissolved radionuclieides everywhere if there's a pinhole, plus they can't go far if they do escape before they freeze solid. MSR systems are really good at being hot, but really bad at making Plutonium for bombs, which is why they were abandoned 40+ years ago.
Nonetheless, nobody died, nobody got even slightly sick (a few minor burns) and apart from the immediate vicinity of the reactors (as in, right up against the containment vessels) the area had lower background radioactivity than the Yorkshire Dales or Denver or downtown Helsinki even before the cleanup crews went in. The dangers of radioactivity are so vastly overblown it's difficult to have a sensible conversation about actual real world risk factors because everyone's terrified of it (yet they think nothing of jumping in an aircraft and flying for hours at an equivalent dose of at least a chest x-ray every hour).
Tepco deserves a major reaming, but that's mostly down to the japanese sense of pride that would prevent them admitting they're out of their depth and asking for outside assistance even if Godzilla was razing Toyko (they actually refused assistance offers). The govt deserves an even bigger reaming for their inept regulatory controls, being too cozily in bed with the power companies and not forcing Tepco to accept outside assistance.
The correct thing to do now is wait 35 years for the caesium compounds to die off then cleanup. That's exactly what's happening at Three Mile Island at the moment. Sending robots in now is a fundamentally bad idea because unless they're left in there they'll track nasty shit back out.
The "highly radioactive" tanks full of water around the plant have about the same levels as you'd find if you dropped a radium watch in an olympic swimming pool and the remaining issue with radioactivity levels has much more to do with the japanese govt having slashed allowable levels by 90% overnight (resulting in fish which was perfectly safe before the accident being dangerously radioactive should you try to sell it now and that's put a lot of people out of business). Whilst you probably wouldn't want to drink from those tanks, it's only slightly more radioactive than seawater and it's safe enough to swim in that I'd feel comfortable doing so (many mineral springs and spas have much higher radioactivity levels, but people are perfectly willing to jump in or "take the waters" those because the radiation is "natural")
The problem is that the laws are misused to take money off individuals _without due process_
I have no problem with $10k or "structuring" being used as a pointer for attention, but extrajudicial confiscation is corrupt activity at its finest.
"It doesn't have to be fast if the job is one that you can scale up and just buy more robots"
And you only have to teach _one_ robot.
Incidentally the first generation of car painting robots in factories were programmed by the simple expedient of memorising the movements as a human pushed the spray nozzles around. I have no idea if it's still done that way
Car workers didn't complain when robots did the dirty stuff like welding/painting, but they didn't like it when they intruded further on the line (even japanese carmakers got (limited) industrial action on this one). At some point humans will kick back against warehouse robots too, but the reality is that robotising most of these kinds of jobs where safety is important (You'd be surprised how many people get killed by forklifts) has a net benefit.
Robot floor pickers exist in a number of areas already, but the final packing and dispatch tends to be done by humans because the mk1 eyeball can spot damaged goods better than an electronic one when everything's mixed up.
> FWIW, there's even a "church-tax" ... in many European countries. here has been a recent trend of people leaving churches in European countries if it allows them to avoid paying these "taxes"
It gets odder than that. In the UK, if you live in a parish then you're liable for costs resulting from the upkeep of the parish church, no matter what your religion (or lack of) is, or if you attend another one somewhere else.
Then again a lot of people identify as "christian" despite never having set foot in a church in their life (The "my parents were so I am" model - this happens with other religions too. I know a bunch of very secular people who say they won't come out as such because it'd upset their muslim or sikh parents)
JWs are fine with plasma, it's whole blood they don't like.
Ion drives have the same issues and there are mitigation techniques available.
I'm busy doing my job.
I don't _want_ recruiters calling/emailing me with vague sniffs of something. If it's more solid than that then sure, but they're paid to find the right person for the job on offer, not to send a bunch of possibles along to interviews. If they're doing that then they're not worth the hassle.
Ditto applies to recruiters who just tick boxes.
Where I work, our experience has almost universally been that what gets sent along by recruiters is the same as (or slightly worse than) the group who see our adverts and apply directly. There's almost no benefit in using them and in most cases they're doing the hopefuls a disservice by talking up their job prospects in order to have more names on their list to offer employers.
"The main reasons for backups (esp. for individuals) are 1) user error, and 2) hardware failure, not acts of god. An on-site NAS protects against those just fine"
It doesn't protect against burglars.
Seriously. We've had several instances at $orkplace of equipment being stolen from staff residences and the backup drives + NAS going too.