The only issue I see is employee safety, and that could be virtually eliminated given a reactor that is designed to shield the workers from the outside excess radiation.
The problem is the Russians won't build reactors with containment domes. Thats why the countryside got zapped. So your solution to the zapped countryside is to build reactors with multiple concentric containment domes. Not gonna happen, at least not in the states of the former USSR. It might fly in the city of Granola, CA, USA, maybe.
There are already some inhabitants, mostly stubborn old people who didn't want to leave their villages and either didn't believe in the seriousness of the threat or considered their deaths from natural causes to be fairly close at hand anyway.
What do the old people eat? Oh, wait, let me freaking guess. The local large mammal population, you know, the one thats mysteriously not recovering, according to the fine article.
It makes sense. Put yourself in place of a starving 80 year old dude. Hmm. I could starve to death tomorrow, seeing as I can't drive my Buick to the local Dennys, because the city is abandoned. Or, I could poach yonder slightly radioactive deer and die of cancer in 50 years. So, uh, 80+50=... hmm... anyone wanna share some venison with me?
In terms of performance, ammonia is one of the best refrigerants in vapor-compression systems.
Yes, but that re-circularizes the argument, back to the original post that if you must have a leak into a confined space, like a space station, you'd have to try really hard to find a worse refrigerant than ammonia, so why in the world would NASA use it, etc. For toxicity reasons I'd still stand by my statement that it is a really cruddy refrigerant for a vapor compression cycle, unless you're doing absorption cycle, in which case its performance is so utterly fantastic I guess we'll have to over look the whole toxicity thing.
Its kind of like the scenario of using propane in a car air conditioner instead of R-22/R-134... Sure it's a tolerably good refrigerant and its pretty much drop in compatible with most lubricant oils, hoses, seals and other parts, but pressurized propane is a pretty cruddy choice for a (probably leaky) automobile air conditioner due to the whole flammability thing, even if its got a decent COP.
after the first few weeks/months, living off-planet would be a hellish claustrophobic monotony punctuated only by the occasional crisis. By the time the first critical life-support system gave out and killed everyone, it's likely that most of the population wouldn't mind dying.
You make it sound like living in New York. I don't think it'll be that bad.
Reason 3 which I forgot to include, is radiation turns ammonia into harmless H2 and N2. Little to no effect on the equipment or thermodynamic properties at any reasonable concentration. If you catch enough gammas to break down 50% of the refrigerant, roughly 50% of the crew mass would have been broken down, indicating bigger problems.
Radiation turns fluorocarbons into fluorine and assorted debris. fluorine, at any concentration, is not good in anything except fluorine tanks. Anthropomorphizing it a bit, F likes to halogenate hydrocarbons like pump oil or plain ole oily contaminants leading to all kinds of entertainment. Its just nasty stuff even at the lowest concentrations. I suppose you could design and install a nice heavy halogen trap, but you'd never Really Know about the internal corrosion levels of the pumps and pipes without very expensive continuous maintenance. The entire refrigeration system would need to be halogen compatible. On earth its not an issue due to low radiation levels and frankly if my A/C pipes corrode out its not life threatening anyway. But not so good of an idea in space.
Finally ammonia is high temperature stable and if you somehow manage to dissociate it anyway, the N2 and H2 are mostly harmless and can be flushed out. On the other hand, SOME of the fluorocarbons have pretty nasty icky byproducts if you overheat them, by, say, the pump shutting down in full sunlight for a long time.
I'm surprised that they would be using ammonia coolants, rather than something more exotic and less toxic... Anybody know why they would have gone with that?
IF its an absorption cycle system, you just can't do better than ammonia. Its hard to find any refrigerant gas that dissolves better in water... absorption cycle is nice on planet earth, no moving parts, no lubricant compatibility issues. In space you need pumps, however.
On the other hand, if its a vapor-compression system like your fridge at home, yes it is in fact a pretty cruddy choice and any of the freon series would kick its butt (as a refrigerant, anyway)
On earth you can play games with gravity to prevent/reduce slugging the compressor in a vapor-compression system. Not sure how you do that in space. Slugging a compressor is when load/airflow is low and you feed a gulp of liquid into the intake instead of moderately hot gas. Its kind of a shock to the innards, its the pump equivalent of eating at Taco Bell...
They should develop artificial gravity. That way their absorption chillers won't need pumps.
Much simpler.
Capillary action heat pipes work even better than pumped absorption chillers, and are even simpler than absorption chillers or artificial gravity. I'm sure we'll discover, this being a NASA project, that some important congressman's vote was purchased by someone in his district manufacturing the pumps. It is theoretically possible NASA made a design choice based on technical reasons such as heat pipes being heavier per watt, although it seems unlikely they'd use criteria like that.
The only part of the hubble that is probably worth recycling is the mirror, since the technology for mirrors hasn't changed much in the last 100 years (unless it can go adaptive/etc).... The mirror doesn't need any moving parts so it should last forever.
One part you're missing is the decay rate. True the technology of mirrors hasn't changed, but that doesn't mean they'll last, unmaintained, forever.
I wonder how quickly the aluminum reflective layer oxidizes in space. Not much O2, but O+ ions are probably even worse. Also outgasing from the rest of the scope condensing back onto the mirror, although you could probably occasionally heat the mirror to clean it.
The mirror will not last forever, or at least the reflective layer will not. It may, however, last a long time.
The other part you're missing is there is no need to launch 4 identical scopes in place of 1. Much more fun to launch an optimized widefield, an optimized IR, and optimized UV, an optimized visible wavelength. Maybe an interfereometer would be fun to launch?
Also its far cheaper to maintain a scope that is extremely nearby the space station, than it is to maintain with robots or shuttles, because you've already got guys in suits sitting there with preplanned resupply missions and perhaps even on-orbit spare parts.
... Once awake, space station astronauts powered down some attitude control systems.... to balance the heat loads on the outpost's backup cooling system, which is working well.
I would have guessed the most important part of the thermal control system was the attitude control system, because the station does not approximate a sphere very well and its got about one hemisphere pointed to cold space and another pointed to "room temperature" earth. But I guess whatever works for them.
Sure, corporations can make a killing...but it will come with a murder conviction.
I seriously doubt it would EVER be legal to remotely disable a pace-maker.
Kind of like it would be illegal for an insurance company not to cover all prescription medicines, or for a pharm company to ever stop manufacturing a pill?
Wouldn't they get more bang for their buck by doing $70 Billion of patent trolling?
Not necessarily anti-open source trolling either. $70 Billion of patent trolling could make quite a dent in the MSSQL market, pushing the end users toward either mysql or oracle. After all, its not an "evil" monopoly if there's a free alternative, conveniently owned by the monopolist...
With hard disks, you can add another platter for more space, or make the diameter bigger.
More platters = manufacturing costs that scale will above linear for obvious mechanical alignment problems. You can drop back to linear scaling obviously by purchasing multiple drives and raiding them. But not so obviously there are serious controller cost and power supply cost limits, pushing you over linear yet again.
As for diameter, that kills power consumption, boot up inrush current draw, various gyroscopic effect problems resulting in expensive platters and bearings, and obviously seek time is killed.
There's no reason to assume that the NAND always has to get smaller, is there?
I don't have the specs in front of me, but most "corporate deployments" use at most double digit gigs. Other than media users / media creators and specialized data warehouse situations no one uses more than double digit gigs. Thats going to be a severe economic pinch on hard drives that can't be economically shrunk, but flash chips can always be made smaller.
But some see maintaining a social network is something they can improve on using a tool specifically designed for the job.
Tool designed specifically to sell your personal information to marketing / pr / HR / credit score companies / Big Brother / "who knows, but it sure won't be to your benefit".
Also, lets face it, facebook is pretty much software support for inane and stupid stuff. Its "friends" in that your friends suffer thru with you, like going to Basic Training together.
I can't see the open alternative website because its slashdotted, but the sarcmark is obvious based on the Debian logo. I'm thinking that's not a coincidence?
Also has a huge bias toward modern religions, whereas its just as likely, if not more so, that some completely dead and (almost) forgotten one is in fact the correct one.
Good luck getting the Carthaginians and Babylonians past that school board.
One was the de'Chardin theory that evolution was teleological, that is, goal-directed toward perfection. Is was their attempt to reconcile evolution and religion. This is not the precise very of evolution, which is non-teleogical, i.e. goal-less.
If you redefine perfection as being "perfectly matched" for their local environment and lifestyle that they have high odds of reproducing, that's actually not too inaccurate. However, they probably have a problem anthropomorphizing it.
I hope they *do* add this to the curriculum, and even get their local batshit-crazy evangelical preachers to come in and teach it.
Everyone enjoys beating the Christians so that would work, one defense they may try is selecting their first "creation science" teacher from a politically correct group such as a traditional native american, or perhaps from a cyclical eastern religion, or maybe a (modern or ancient) pagan, then later roll out the christian evangelicals, once "sunday school mon-fri" is accepted.
Any observation anyone makes can simply be explained by "God made it that way." There is no way to refute it with evidence-- it is a belief-based system that depends on supreme being instead of natural processes.
Actually its pretty easy to refute. Just get advocates of different belief systems together and let them logically debate and come to a mutually acceptable solution, like scientists would about any other topic.
I'm sure the "creation science" views of a traditional Roman pagan, a modern Christian, a Native American, and some eastern cyclical religion would probably refute each other quite well.
Anyone else think it odd that Disney is running a puff piece for one of its major shareholders?
Somewhere around 5 media companies control about 99% of what the general population sees, hears, reads, and frankly, thinks.
So, if a rich dude invests in a major media company, then pretty much by definition there is about a 1 in 5 chance that a report from a major media outlet will be covering one of their own shareholders.
Its not like we have a free market of numerous equal competitors trying to push commodities in the media world.
Still not seeing the point. You have a pool of one zillion people and only a tenth of a zillion jobs, time to start chopping, and any vaguely acceptable reason to winnow out the field is acceptable. Don't like it, try a profession that isn't dying.
I have recently signed up for facebook because my friends stopped calling and texting people and just started posting "I'll be at blah blah blah at 8pm tonight, come along". I was missing out on a lot of fun things I could possibly be doing because I didn't have an account, so now I have one.
That's the same reason I deleted mine. Kid whom sat at the same lunch table as me in 8th grade posted every single time he entered or left a restaurant or bar (kind of like a manual foursquare). I guess I could go alone, unfortunately he now lives almost 3000 miles away. Dude I worked with a decade ago posts every time he goes to the gym, for motivation, I guess. I guess I could go along, unfortunately he lives 200 miles away. Same deal with the guy who was my high school physics lab partner, now living about 100 miles away.
When I got rid of all the pseudo-spammers and ignored all my far away "old friends" there wasn't really enough left to bother keeping the account... So I used this "new" feature in May to delete it, and nobody seems to care except my wife.
Slashdot Mirror
The only issue I see is employee safety, and that could be virtually eliminated given a reactor that is designed to shield the workers from the outside excess radiation.
The problem is the Russians won't build reactors with containment domes. Thats why the countryside got zapped. So your solution to the zapped countryside is to build reactors with multiple concentric containment domes. Not gonna happen, at least not in the states of the former USSR. It might fly in the city of Granola, CA, USA, maybe.
There are already some inhabitants, mostly stubborn old people who didn't want to leave their villages and either didn't believe in the seriousness of the threat or considered their deaths from natural causes to be fairly close at hand anyway.
What do the old people eat? Oh, wait, let me freaking guess. The local large mammal population, you know, the one thats mysteriously not recovering, according to the fine article.
It makes sense. Put yourself in place of a starving 80 year old dude. Hmm. I could starve to death tomorrow, seeing as I can't drive my Buick to the local Dennys, because the city is abandoned. Or, I could poach yonder slightly radioactive deer and die of cancer in 50 years. So, uh, 80+50= ... hmm ... anyone wanna share some venison with me?
In terms of performance, ammonia is one of the best refrigerants in vapor-compression systems.
Yes, but that re-circularizes the argument, back to the original post that if you must have a leak into a confined space, like a space station, you'd have to try really hard to find a worse refrigerant than ammonia, so why in the world would NASA use it, etc. For toxicity reasons I'd still stand by my statement that it is a really cruddy refrigerant for a vapor compression cycle, unless you're doing absorption cycle, in which case its performance is so utterly fantastic I guess we'll have to over look the whole toxicity thing.
Its kind of like the scenario of using propane in a car air conditioner instead of R-22/R-134... Sure it's a tolerably good refrigerant and its pretty much drop in compatible with most lubricant oils, hoses, seals and other parts, but pressurized propane is a pretty cruddy choice for a (probably leaky) automobile air conditioner due to the whole flammability thing, even if its got a decent COP.
after the first few weeks/months, living off-planet would be a hellish claustrophobic monotony punctuated only by the occasional crisis. By the time the first critical life-support system gave out and killed everyone, it's likely that most of the population wouldn't mind dying.
You make it sound like living in New York. I don't think it'll be that bad.
Reason 3 which I forgot to include, is radiation turns ammonia into harmless H2 and N2. Little to no effect on the equipment or thermodynamic properties at any reasonable concentration. If you catch enough gammas to break down 50% of the refrigerant, roughly 50% of the crew mass would have been broken down, indicating bigger problems.
Radiation turns fluorocarbons into fluorine and assorted debris. fluorine, at any concentration, is not good in anything except fluorine tanks. Anthropomorphizing it a bit, F likes to halogenate hydrocarbons like pump oil or plain ole oily contaminants leading to all kinds of entertainment. Its just nasty stuff even at the lowest concentrations. I suppose you could design and install a nice heavy halogen trap, but you'd never Really Know about the internal corrosion levels of the pumps and pipes without very expensive continuous maintenance. The entire refrigeration system would need to be halogen compatible. On earth its not an issue due to low radiation levels and frankly if my A/C pipes corrode out its not life threatening anyway. But not so good of an idea in space.
Finally ammonia is high temperature stable and if you somehow manage to dissociate it anyway, the N2 and H2 are mostly harmless and can be flushed out. On the other hand, SOME of the fluorocarbons have pretty nasty icky byproducts if you overheat them, by, say, the pump shutting down in full sunlight for a long time.
I'm surprised that they would be using ammonia coolants, rather than something more exotic and less toxic ... Anybody know why they would have gone with that?
IF its an absorption cycle system, you just can't do better than ammonia. Its hard to find any refrigerant gas that dissolves better in water... absorption cycle is nice on planet earth, no moving parts, no lubricant compatibility issues. In space you need pumps, however.
On the other hand, if its a vapor-compression system like your fridge at home, yes it is in fact a pretty cruddy choice and any of the freon series would kick its butt (as a refrigerant, anyway)
On earth you can play games with gravity to prevent/reduce slugging the compressor in a vapor-compression system. Not sure how you do that in space. Slugging a compressor is when load/airflow is low and you feed a gulp of liquid into the intake instead of moderately hot gas. Its kind of a shock to the innards, its the pump equivalent of eating at Taco Bell...
http://en.wikipedia.org/wiki/Refrigeration#Cyclic_refrigeration
They should develop artificial gravity. That way their absorption chillers won't need pumps.
Much simpler.
Capillary action heat pipes work even better than pumped absorption chillers, and are even simpler than absorption chillers or artificial gravity. I'm sure we'll discover, this being a NASA project, that some important congressman's vote was purchased by someone in his district manufacturing the pumps. It is theoretically possible NASA made a design choice based on technical reasons such as heat pipes being heavier per watt, although it seems unlikely they'd use criteria like that.
The only part of the hubble that is probably worth recycling is the mirror, since the technology for mirrors hasn't changed much in the last 100 years (unless it can go adaptive/etc) .... The mirror doesn't need any moving parts so it should last forever.
One part you're missing is the decay rate. True the technology of mirrors hasn't changed, but that doesn't mean they'll last, unmaintained, forever.
I wonder how quickly the aluminum reflective layer oxidizes in space. Not much O2, but O+ ions are probably even worse. Also outgasing from the rest of the scope condensing back onto the mirror, although you could probably occasionally heat the mirror to clean it.
The mirror will not last forever, or at least the reflective layer will not. It may, however, last a long time.
The other part you're missing is there is no need to launch 4 identical scopes in place of 1. Much more fun to launch an optimized widefield, an optimized IR, and optimized UV, an optimized visible wavelength. Maybe an interfereometer would be fun to launch?
Also its far cheaper to maintain a scope that is extremely nearby the space station, than it is to maintain with robots or shuttles, because you've already got guys in suits sitting there with preplanned resupply missions and perhaps even on-orbit spare parts.
Maybe the reason the space station article has so few comments is because they're appearing in other articles instead?
... Once awake, space station astronauts powered down some attitude control systems .... to balance the heat loads on the outpost's backup cooling system, which is working well.
I would have guessed the most important part of the thermal control system was the attitude control system, because the station does not approximate a sphere very well and its got about one hemisphere pointed to cold space and another pointed to "room temperature" earth. But I guess whatever works for them.
Sure, corporations can make a killing...but it will come with a murder conviction.
I seriously doubt it would EVER be legal to remotely disable a pace-maker.
Kind of like it would be illegal for an insurance company not to cover all prescription medicines, or for a pharm company to ever stop manufacturing a pill?
Wouldn't they get more bang for their buck by doing $70 Billion of patent trolling?
Not necessarily anti-open source trolling either. $70 Billion of patent trolling could make quite a dent in the MSSQL market, pushing the end users toward either mysql or oracle. After all, its not an "evil" monopoly if there's a free alternative, conveniently owned by the monopolist...
your iAlchemist can use the power of alchemy to turn lead into gold!
Uh, we're lead free solder here, thank you.
With hard disks, you can add another platter for more space, or make the diameter bigger.
More platters = manufacturing costs that scale will above linear for obvious mechanical alignment problems. You can drop back to linear scaling obviously by purchasing multiple drives and raiding them. But not so obviously there are serious controller cost and power supply cost limits, pushing you over linear yet again.
As for diameter, that kills power consumption, boot up inrush current draw, various gyroscopic effect problems resulting in expensive platters and bearings, and obviously seek time is killed.
There's no reason to assume that the NAND always has to get smaller, is there?
I don't have the specs in front of me, but most "corporate deployments" use at most double digit gigs. Other than media users / media creators and specialized data warehouse situations no one uses more than double digit gigs. Thats going to be a severe economic pinch on hard drives that can't be economically shrunk, but flash chips can always be made smaller.
purchasing engine parts that don't follow quality control guidelines is also an act of God.
According to "intelligent design" those were put there by the devil to fool us.
But some see maintaining a social network is something they can improve on using a tool specifically designed for the job.
Tool designed specifically to sell your personal information to marketing / pr / HR / credit score companies / Big Brother / "who knows, but it sure won't be to your benefit".
Also, lets face it, facebook is pretty much software support for inane and stupid stuff. Its "friends" in that your friends suffer thru with you, like going to Basic Training together.
I can't see the open alternative website because its slashdotted, but the sarcmark is obvious based on the Debian logo. I'm thinking that's not a coincidence?
Also has a huge bias toward modern religions, whereas its just as likely, if not more so, that some completely dead and (almost) forgotten one is in fact the correct one.
Good luck getting the Carthaginians and Babylonians past that school board.
One was the de'Chardin theory that evolution was teleological, that is, goal-directed toward perfection. Is was their attempt to reconcile evolution and religion. This is not the precise very of evolution, which is non-teleogical, i.e. goal-less.
If you redefine perfection as being "perfectly matched" for their local environment and lifestyle that they have high odds of reproducing, that's actually not too inaccurate. However, they probably have a problem anthropomorphizing it.
I hope they *do* add this to the curriculum, and even get their local batshit-crazy evangelical preachers to come in and teach it.
Everyone enjoys beating the Christians so that would work, one defense they may try is selecting their first "creation science" teacher from a politically correct group such as a traditional native american, or perhaps from a cyclical eastern religion, or maybe a (modern or ancient) pagan, then later roll out the christian evangelicals, once "sunday school mon-fri" is accepted.
Any observation anyone makes can simply be explained by "God made it that way." There is no way to refute it with evidence-- it is a belief-based system that depends on supreme being instead of natural processes.
Actually its pretty easy to refute. Just get advocates of different belief systems together and let them logically debate and come to a mutually acceptable solution, like scientists would about any other topic.
I'm sure the "creation science" views of a traditional Roman pagan, a modern Christian, a Native American, and some eastern cyclical religion would probably refute each other quite well.
Anyone else think it odd that Disney is running a puff piece for one of its major shareholders?
Somewhere around 5 media companies control about 99% of what the general population sees, hears, reads, and frankly, thinks.
So, if a rich dude invests in a major media company, then pretty much by definition there is about a 1 in 5 chance that a report from a major media outlet will be covering one of their own shareholders.
Its not like we have a free market of numerous equal competitors trying to push commodities in the media world.
Still not seeing the point. You have a pool of one zillion people and only a tenth of a zillion jobs, time to start chopping, and any vaguely acceptable reason to winnow out the field is acceptable. Don't like it, try a profession that isn't dying.
Its easier to delete your own account, plus that improves your life by decluttering it.
I have recently signed up for facebook because my friends stopped calling and texting people and just started posting "I'll be at blah blah blah at 8pm tonight, come along". I was missing out on a lot of fun things I could possibly be doing because I didn't have an account, so now I have one.
That's the same reason I deleted mine. Kid whom sat at the same lunch table as me in 8th grade posted every single time he entered or left a restaurant or bar (kind of like a manual foursquare). I guess I could go alone, unfortunately he now lives almost 3000 miles away. Dude I worked with a decade ago posts every time he goes to the gym, for motivation, I guess. I guess I could go along, unfortunately he lives 200 miles away. Same deal with the guy who was my high school physics lab partner, now living about 100 miles away.
When I got rid of all the pseudo-spammers and ignored all my far away "old friends" there wasn't really enough left to bother keeping the account... So I used this "new" feature in May to delete it, and nobody seems to care except my wife.