proliferation issues are utterly irrelevant to a discussion of how much nuclear power costs
On the contrary, they are valid externalities, and we ignore them at our peril and that of our decendants.
Please don't ask me to support your cheap nuclear power when doing so means that the empowered radicals obtain cheaper nuclear weapons.
Now I *know* you're trolling.
Nuclear plants are big, expensive, and impossible to hide (gamma signature can penetrate just about anything if you take the time to look for it). Any nation with one that's active has it active because the rest of the world allows it.
Lastly, whether or not North America or $non_threat_nation uses nuclear power has absolutely no effect on whether $rogue_state_du_jour decides to build a reactor. The methods of construction and operation are well known. Canada could dismantle all of its nuclear plants and India and Pakistan and North Korea would still be making bombs.
How exactly is my supporting nuclear power in Canada proliferating nuclear weapons, again?
How does proliferation relate to the half-dozen "nuclear power is ludicrously expensive" posts you littered this thread with?
I've seen enough diversion tactics to be able to shoot them down. Keep trying.
The moon is an excellent source of Helium-3, which when reacted with Hydrogen-1 provides much cleaner, and more importantly, lower activation energy fusion than H3-H2 or H2-H2 fusion.
Actually, D+T is still far easier. He3+_D_ is about on par with D+D, and more importantly produces an energetic _proton_ as the decay product. He3 will not fuse with p, as that would give you something like Li4 (no dice).
D+T is easy but produces a boatload of neutrons, which carry away most of the reaction energy. As these aren't confined by the reactor's magnetic field, you're stuck letting the shielding material heat up and drawing power off of it with a heat engine. The reactor vessel itself rapidly degrades due to intense neutron radiation.
You also need to produce a steady supply of T, but you can breed that from a lithium blanket, or just surround the reactor vessel with heavy water and let it breed from D.
D+D fusion is a bit cleaner than D+T, but much harder to achieve. It produces He3+n half the time and T+p the other half. The T will react very quickly to produce He4+n, which carries away most of the energy in the neutron. If you don't have a long confinement time, you're stuck with this. If you do have a long confinement time, the He3 will burn with D to produce He4+p, which carries away a lot of the energy in the p, which stays confined, heats the plasma, and is otherwise nice.
Summary for D+D: Only decent if you can keep it confined for a while, still releases half its energy as neutrons, much harder than D+T.
He3+D is slightly easier than D+D, but still in the same ballpark (much harder than D+T). Most importantly, He3+D gives He4+p, so almost all of your energy ends up in charged particles. The problem is that you get D+D happening as long as there's D in the plasma, so you have to run a reactor with much more He3 than D, and still get neutrons coming out - just much less than with D+D. This means your reactor vessel lasts at least 10 times longer, your plasma heats itself, and you can use higher-efficiency methods of tapping power if you want to.
The problem is that He3 is rare, and trying to breed it via D+D just gives you a D+D reactor, with its neutron problem.
If there's a lot of He3 on the moon and it's relatively easily harvested, it may be a viable source of fuel. I have my doubts about this being practical (I think we'd be better off filtering it out of natural helium, though that's not a picnic either, as it's much rarer than deuterium).
In terms of mining, minerals, resources we could acquire out there, if it takes China or whoever else to spank around the U.S. and make them realise that they'll gladly take the whole pie if we do nothing about it.
We are sitting on top of a very large sphere of mineral resources. Space-based sources are generally only better-priced if the materials are going to be _used_ in space, which gives a nice chicken-and-egg problem.
On the other hand, if people would finally lay their bussiness interests to rest and start thinking about what's good for people, we'll be *there* in no time.
Space exploration is not "good for people", and won't be any time soon. It's good for the _species_, in the very long term (once self-sufficient colonies are established), but if there's one thing humanity has consistently demonstrated, it's that this is not a major motivation to them.
Joe Average will gain no direct benefit, and debatable indirect benefits, from a new space race. The best we can hope for are that new high-performance materials will be developed sooner (they'd still be developed either way).
Even a space elevator won't make space emigration possible for most people. Cost is limited by throughput, which ends up being pretty low (meaning your tether cost is amortized over a relatively small amount of cargo). This means that vacations will be for the well-to-do, and moving out permanently will be for the rich only (you can't build everything you need at the destination until you have a minimum industrial base there, and lifting it there costs money; ditto building a transport to the moon or to Mars or the asteroids or Lagrange colonies).
In short, people as individuals won't benefit from space travel unless there's a business benefit. So far, there isn't a good enough case to say one exists, so it's staying in the national prestige contest arena.
In fact the last number I quoted before this thread was $0.45/kwh, which came from Googled material via "Price-Anderson Act" (which was in the news less than a year ago having been up for renewal) relating to an actuarial bid from Lloyds of London, quoted was during the Chernobyl era. Granted, however, that it has been a long time since any commercial insurance company was asked to bid on a nuclear power coverage policy.
I suspect that the number would be significantly lower in Ontario (and likely the rest of Canada), given that we've had a total of two accidents (pipes bursting) over the course of our entire nuclear power program, resulting in zero release of radioactive material to the environment and zero deaths/injuries. There was a release of heavy water containing trace amounts of tritium at one point too, but even near the plant the amount was well below internationally defined safe levels (by about a factor of 10).
The fact is, until the market is asked to bear these risks, instead of the taxpayers, nobody will know how much it costs to insure nuclear electricity. $0.20/kwh is a guess, not a quote.
My objection is to this "guess" being put forth as fact, and used in a costing analysis. The current insurance cost for nuclear risks has been zero, as there have been no payouts in decades of operation.
Insurance not related to nuclear exposure (e.g. insurance against damage to the plant and so forth) is already handled commercially in Ontario, and so already a part of the cost of power.
In summary, the cost at which nuclear power is sold in Ontario has, over the past several decades, has been a reasonable approximation of the cost required to produce it, including costs resulting from liability for accidents.
I'm tired of people ignoring the background proliferation issues.
These proliferation issues are utterly irrelevant to a discussion of how much nuclear power costs to produce relative to other power generation methods.
Correct me if I am wrong, but Canada provides government-sponsored insurance to nuclear facilities just like the U.S. does. My understanding is that if nuclear plants were forced to obtain market rate insurance, the cost of nuclear power would be very much over $0.20/kwh.
You keep throwing this number around, but have yet to provide any source or justification for it.
In Ontario alone, that would amount to $13 _billion_ annually (half of our power generation is nuclear). That would be kind of noticeable in the budget.
Nanomanufacturing could create perfectly spherical containment vessels.
a) Containment vessels for magnetic confinement fusion are toroidal (or variants thereof), not spherical.
b) Precise containment vessel geometry doesn't much affect stability. Plasma turbulence causes stability to degrade. Hence, the active compensation mechanisms that were played with in recent memory.
Please read any of the available FAQs on magnetic confinement fusion.
"These micro-engines have over 300 times more energy than an ordinary battery and are much lighter and smaller."
So a cellphone that needs a daily charging will now need a refill once a year? I would wager that this claim carries a degree of exaggeration.
The 300x almost certainly refers to energy density (per unit mass or per unit volume; pick one). This is consistent with switching from batteries to chemical fuels (though still a bit optimistic). The thing is, a fuel cell will do the same thing with _zero_ moving parts, instead of the one-moving-part micro-turbine, or this very complicated engine.
Look forwards to refilling your cell phone about once a month when fuel cells are integrated in production models (prototypes have existed for a while now). Both fuel cells and micro-turbines have problems with heat generation, though.
The problem with fusion is not materials. You cannot get a material that will contain a fusion reaction - instead they use magnetic containment. And the problem is keeping the thing stable. I cannot see how nanotech devices would assist in this.
Better materials would help substantially with magnetic confinement fusion. In particular, something with a high tensile strength and a superconductor with high breakdown field strength would make many of the difficulties with magnetic confinement fusion magically go away. Higher field strength helps a *lot* (improving both density and confinement time).
I agree that nanotechnology is unlikely to help with this.
I personally would be extremely cautious with this issue on a level similar to the moral dilema of cloning humans. We don't even understand most of the genetic code of our own species, how the genes interact, or even what they're there for, and we intend to do direct manipulation of genes?
You do realize that the whole point of a clone is that the genetic material _isn't_ changed, right?
The real reason why human cloning is presently a bad idea is that 99 out of 100 clones will _die_ because our current techniques are lousy. Given a perfect technique, cloning ends up being in-vitro fertilization that gives you a twin 20+ years younger than you are. Where's the problem?
Given that biological life has this tendancy to mutate, how do we know what effect this genetic manipulation would have in 2 generations? How about 5? Or 10?
The same argument applies to all life. As we presumably don't worry about our non-engineered house pets mutating into monsters, I wouldn't worry too much about mutation affecting GM organisms.
There _are_ good reasons to be worried about GM foods, but you haven't listed any of them yet. It will be entertaining to see if you get around to citing them or not. GM organisms could be dangerous if deliberately built to be, but that's about it.
Of course, for $20 million a person, you could launch 7 people - the compliment of a shuttle - for $140m. The average shuttle flight costs $500m.
That's the complement when they're hauling cargo too. Keep the cargo, and the fare for the cargo covers most of the launch cost. Lose the cargo, and you can put a passenger/life support module into the cargo bay and carry more passengers.
The grand assumption is that you can find enough people willing to pay $20M for a week in space to make this profitable on the long term, however. I think you'd run out of $100M-ares pretty quickly.
1970's-1990's - Here is where transportation advancement largely drops off. We've gotten more efficient jets. Rocket technology hasn't gotten any better. Cars have gotten more efficient. Other than some efficiency tweaks, we haven't advanced much at all in transportation since the exceedingly rapid advancements of the mid 20th century.
We've actually gotten off our tails and put ion drives and other electric thrusters into production and (semi-) widespread use. Any time you see "Hall effect thruster" in a satellite's description, that's an example of relatively recent space engineering doing its job.
Groundside, we've had steady improvement of fuel cell technology over the past several decades, which has reached the point where fuel cell powered electric devices from cell phones to cars are becoming practical (several prototypes to date). Unlike battery power, the energy storage density of fuel cell systems is comparable to that of gasoline, so we might actually see zero-emission vehicles in the near future. (Yes, emissions happen if you use fossil fuel plants to generate hydrogen or methanol, but you can put _scrubbers_ on a power plant, and change energy production methods in the power grid more easily than change all of the cars on the road.)
Lastly, bear in mind that all technologies peak after a while. The reason cars today look a lot like cars 50 years ago is that the fundamental design is pretty _good_. Many details change, and many incremental improvements are made, but the lack of a radically different design suggests that, over the time in question, a radically better option didn't exist.
Then I learned what you mentioned about it not being a data specification...and it was totally lost on me why XML is of any value whatsoever.
I'm using it for some of my own projects because of the XML parsing libraries. I'll often be using configuration or data files, and it's a pain to have to write a parser each and every time.
YMMV. I consider it a useful, if over-hyped, tool.
What is open? Are you serious? There is a simple and well-layed out spec for HTML, XML, TCP/IP, etc, etc. Use them to spec and don't allow perversions that intentionally break intercommunication/interoperability.
XML is not a data format specification - it's a framework within which data format specifications can be built. Convert documents, spreadsheets, CAD files, and what-have-you to XML and they will be just as incompatible as ever.
All you need is thrust, lift is just one kind of thrust, the rotating blades of a helicopter, produce a lifting force which is the thrust that lifts the aircraft. Other sources of thrust would work as well [jet engine for instance (yes, modern jets do contain airfoils, but they don't need to in order to be a jet and produce thrust)]
For any craft with less than 1g of thrust, you need wings to provide the lift. This is what my airfoil comment was referring to. Helicopter blades were mentioned as a special case, as they could equally validly be considered wings or a thrust-producing device.
There's a world of difference between a jet engine and a rocket engine.
No, they are both devices that expel matter with a higher momentum than it was acquired at, in the case of a rocket you carry the matter with, and in the case of a jet, you pick it up along the way, fundamentally the same.
A water pistol is also a device that expels a jet of matter with greater momentum with which it was acquired. As I'm sure you appreciate, the engineering concerns with propeller, jet, and rocket engines are vastly different. My point was that the development of the first does not make development of the third a minor feat.
yes there is a drastic difference in the amount of technology required for atmospheric flight and space flight, but it is an evolutionary difference, not a revolutionary difference.
I respectfully disagree, especially since the original context was one of going from propeller planes to spaceflight.
Once manned heavier-than-air flight was demonstrated, going to the moon was pretty inevitable
Um, no.
Flight through the atmosphere with heavy craft and launching something into space are almost completely unrelated problems.
For the first, you need to figure out how airfoils work to produce lift (helicopter blades count in this category), and figure out how to move the air that surrounds your craft to produce thrust. Then there's materials engineering to get the performance to weight ratio nice enough.
For the second, you have to figure out celestial mechanics, and you have to figure out how to build reaction drives that _don't_ use the surrounding medium to move (as you won't have air around you for much of your trip, and it's more of a hindrance than a help at significant speed). Then you have the herculean task of materials engineering and clever craft design required to get an impulse-to-weight ratio large enough to escape the gravity well (or at least have enough delta-v for orbit). If the gravity well was even a little deeper, we wouldn't have been able to do it with chemical rockets at all (though aircraft would still be easy to build).
There's a world of difference between a jet engine and a rocket engine. There's a world of difference between something light and strong enough to glide and something light and strong enough to have a 40:1 wet:dry weight and make orbit. It's not a difference of scale - it's a difference of fundamental type of device.
In summary, please do more research about exactly what's involved in each task before proclaiming that one follows from the other. What actually precipitated _both_ was the industrial revolution, which gave a drastic increase in technology and in materials science.
But here's the point: exploring an icy moon billions of kilometres away with a nuclear-powered spacecraft, which is the topic of the story, will probably not change the global balance of power.
No, but creating the infrastructure and public opinion change that would allow the US military to put fission and fusion reactors into space will affect the balance of power.
Actually, I doubt it. The kinds of reactor used on this style of probe are completely useless as weapons, and require no industry retooling. What you'd have to worry about would be a) warheads in space, and b) _large_ fission reactors in space. Completely different beasts.
Oh, and for all those who believe that we should be designing a manned mission to Mars, let me be perfectly clear:
The only way we will get humans to Mars will be using nuclear propulsion and nuclear power sources(RTGs). Period.
Um, no.
Check out the raft of Mars Direct papers for a description of how to do it with chemical rockets.
Using nuclear (NERVA-style) instead of chemical gave you more payload, but didn't fundamentally change the nature of the task.
RTGs are useless for manned propulsion, because their power to weight ratio is low (despite a high _energy_ to weight ratio). They're useless for _un_manned propulsion too, unless you have a mission time of decades. Past RTG launches have used them to power electronics. The mission the article refers to uses a _reactor_, which is a very different beast than a radiothermal generator (much higher power to weight but much more complex).
The "renewable" energy sources such as Wind, Solar, and Geothermal energy don't have a lot of chance of being particularly useful. However, if they're going to be useful at ALL, people have to recognize that they're only going to be useful in *very specific places*.
That may or may not be true for wind power, but solar power can operate just about anywhere. Unless you're in the land of eternal rain, you'll have more than enough sunny days to generate quite a lot of power. You just need about a week's worth of power storage (probably by building an off-the-shelf fuel cell station next to your solar generator; full-scale fuel cell facilities have been online for a while now).
The energy per unit land area of sunlight is very high (on the order of 1 kW/m^2 at maximum), making the total area required for even a many-gigawatt plant quite small (about the size of the large city it powers; far smaller than the farmland that feeds that city). Before anyone grouses about photovoltaics, the large-scale solar plants to date have used mirrors to heat a working fluid, which then boils water to drive turbines just as a fossil fuel or nuclear plant does.
This is where I think we'll end up going in the long run. Other renewable schemes tend to be site-specific, low power density, or both. Fossil fuel pollutes horribly even with scrubbers and will get gradually more expensive as reserves dry up. Nuclear requires a large investment in the plant, constant maintenance, and is a political nightmare. Solar in various forms can provide power on scales from "personal" to "large city", without much in the way of drawbacks.
The heavily subsidized typical cost for U.S. nuclear power is around $0.12/kwh [...] The unsubsidized, fully amortized cost of wind power is about $0.04/kwh.
That's funny, we use nuclear plants for a lot of our power here in Ontario and our cost of power is about 4 cents per kWh *Canadian*.
How about backing up your numbers, instead of cutting and pasting the same rant, hmm?
But you imply something quite scary: Do humans have the right to determine which species ar contributing to the ecosystem, and exterminate the rest? Are we capable of doing this? qualified? What if we make a mistake?
Why would we not have the right to mold the world as we see fit? If we don't, who does, and on what authority are we forbidden from making changes?
I agree that large-scale mucking about may be dangerous for us - we're near the top of the ecosystem, and so in a relatively fragile position - but abstaining from making changes on that basis is a question of prudence, not of "rights".
I believe that it is a better solution to identify the areas we are having the most impact, minimize it, and let nature run its course. Let's not second guess nature. It's done a good job of maintaining things long before we were around...:-)
Nature has no grand plan, though. It's literally a random process, and most definitely doesn't have our welfare in its best interest - it _has_ no interests. If anything, we should expect life to become more difficult for us if we leave it to nature's ebb and flow (we multiplied because there was a favourable environment, but environments change).
In summary, I do not see why nature running unhindered would work towards any human-oriented goal.
On the other hand, this entire debate is rather silly without a set of goals everyone agrees on:). I'm just trying to throw thought-provoking questions at you.
p.s. specialized OS don't crash because it's exactly that - specialized. I think windows crash so much because (part of the reason) it runs on so many kinds of hardware, for one. As much as I will get flamed, in OEM applications, like, say, most of the new fancy I-will-never-be-able-to-affort oscilloscopes and the likes, windows usually don't crash.
The purpose of an operating system is to provide an abstraction layer between the hardware and application software, and between all of the tasks running on a machine. If done right, this prevents most crashing no matter what you're doing (as most software doesn't have the privileges needed to take down the whole system). If done wrong, application software can muck with things it shouldn't, and the whole system comes crashing down when something goes wrong.
Any of the 9x series of Windows, and WinME, fall into the second category. Windows NT (including 2K and XP), and various Unix flavours and clones (including MacOS X), fall into the first category.
While a general-purpose system has more potential points of failure in software - as you're running more software - this is not an excuse for it to be crash prone. A well-protected OS is vulnerable to bugs in the OS core and in the drivers interfacing with hardware, which will for the most part still be there even in a single-purpose system.
In summary, you can't blame windows crashing on it being a general-purpose operating system. There are plenty of general-purpose OSs that crash far less. There are special-purpose OSs that are designed shoddily, as well (it's just easier to catch that before it goes to market, because the test space is smaller).
FWIW, re. another thread, my understanding is that WinCE is a stepchild of NT (heavy rewrite to make it modular and to pare out functionality that isn't needed in embedded systems, while keeping most of the core OS design). That should make its behavior similar to that of NT.
Yes, NASA has launches probes powered by radioactive decay. There's a big difference between that and a rocket with an active nuclear reaction in its engine.
Read the article. This uses an ion drive and a nuclear-electric generator. The concept drawing has these at opposite ends of the craft, so there are no exhaust stream issues.
You could build a craft like this using the same kind of radiothermal generators that have been used in previous missions. This craft specs a power source a hundred times stronger, which means either an RTEG with an isotope that's a hundred times shorter lived, or an induced fission reactor (see below).
What if the rocket blows up?
Any fuel pellets sent up in a space probe will be encased in shells that can survive explosion and re-entry. This is already proven technology, tested for sending up the RTEGs that are already used.
Rocket explodes, fuel pellets land intact in the debris field, fuel pellets are collected by hazmat teams without contaminating the surroundings.
What if it's cold and the O-ring on a control rod cracks, causing the reactor to overheat?
An RTEG is sub-critical - there is no failure mechanism.
If it's an induced fission reactor (the kind that needs control), it'll almost certainly be a self-balancing one like the Slowpoke that has no moving parts (it has to last for decades with no maintenance). You couldn't destabilize a reactor like that if you _wanted_ to, and it requires no active control.
The way these reactors work is that the support frame and/or the housings for the fuel pellets use a material with a very high rate of thermal expansion; turn up the heat, and the fuel pellets move farther apart, shutting down the reactor - it balances just on the edge of shutoff.
Damage it, and at worst you break it up, causing instant shutdown (there's no longer enough material in one place for criticality).
What if the launch has to be aborted before the rocket has reached orbital velocities and the reactor has to fall to earth?
Then the rocket is detonated, and you have the same thing happening as with a rocket explosion - several dozen radioactive marbles, intact, littering the landscape.
Slashdot Mirror
proliferation issues are utterly irrelevant to a discussion of how much nuclear power costs
On the contrary, they are valid externalities, and we ignore them at our peril and that of our decendants.
Please don't ask me to support your cheap nuclear power when doing so means that the empowered radicals obtain cheaper nuclear weapons.
Now I *know* you're trolling.
Nuclear plants are big, expensive, and impossible to hide (gamma signature can penetrate just about anything if you take the time to look for it). Any nation with one that's active has it active because the rest of the world allows it.
Lastly, whether or not North America or $non_threat_nation uses nuclear power has absolutely no effect on whether $rogue_state_du_jour decides to build a reactor. The methods of construction and operation are well known. Canada could dismantle all of its nuclear plants and India and Pakistan and North Korea would still be making bombs.
How exactly is my supporting nuclear power in Canada proliferating nuclear weapons, again?
How does proliferation relate to the half-dozen "nuclear power is ludicrously expensive" posts you littered this thread with?
I've seen enough diversion tactics to be able to shoot them down. Keep trying.
The moon is an excellent source of Helium-3, which when reacted with Hydrogen-1 provides much cleaner, and more importantly, lower activation energy fusion than H3-H2 or H2-H2 fusion.
Actually, D+T is still far easier. He3+_D_ is about on par with D+D, and more importantly produces an energetic _proton_ as the decay product. He3 will not fuse with p, as that would give you something like Li4 (no dice).
D+T is easy but produces a boatload of neutrons, which carry away most of the reaction energy. As these aren't confined by the reactor's magnetic field, you're stuck letting the shielding material heat up and drawing power off of it with a heat engine. The reactor vessel itself rapidly degrades due to intense neutron radiation.
You also need to produce a steady supply of T, but you can breed that from a lithium blanket, or just surround the reactor vessel with heavy water and let it breed from D.
D+D fusion is a bit cleaner than D+T, but much harder to achieve. It produces He3+n half the time and T+p the other half. The T will react very quickly to produce He4+n, which carries away most of the energy in the neutron. If you don't have a long confinement time, you're stuck with this. If you do have a long confinement time, the He3 will burn with D to produce He4+p, which carries away a lot of the energy in the p, which stays confined, heats the plasma, and is otherwise nice.
Summary for D+D: Only decent if you can keep it confined for a while, still releases half its energy as neutrons, much harder than D+T.
He3+D is slightly easier than D+D, but still in the same ballpark (much harder than D+T). Most importantly, He3+D gives He4+p, so almost all of your energy ends up in charged particles. The problem is that you get D+D happening as long as there's D in the plasma, so you have to run a reactor with much more He3 than D, and still get neutrons coming out - just much less than with D+D. This means your reactor vessel lasts at least 10 times longer, your plasma heats itself, and you can use higher-efficiency methods of tapping power if you want to.
The problem is that He3 is rare, and trying to breed it via D+D just gives you a D+D reactor, with its neutron problem.
If there's a lot of He3 on the moon and it's relatively easily harvested, it may be a viable source of fuel. I have my doubts about this being practical (I think we'd be better off filtering it out of natural helium, though that's not a picnic either, as it's much rarer than deuterium).
In terms of mining, minerals, resources we could acquire out there, if it takes China or whoever else to spank around the U.S. and make them realise that they'll gladly take the whole pie if we do nothing about it.
We are sitting on top of a very large sphere of mineral resources. Space-based sources are generally only better-priced if the materials are going to be _used_ in space, which gives a nice chicken-and-egg problem.
On the other hand, if people would finally lay their bussiness interests to rest and start thinking about what's good for people, we'll be *there* in no time.
Space exploration is not "good for people", and won't be any time soon. It's good for the _species_, in the very long term (once self-sufficient colonies are established), but if there's one thing humanity has consistently demonstrated, it's that this is not a major motivation to them.
Joe Average will gain no direct benefit, and debatable indirect benefits, from a new space race. The best we can hope for are that new high-performance materials will be developed sooner (they'd still be developed either way).
Even a space elevator won't make space emigration possible for most people. Cost is limited by throughput, which ends up being pretty low (meaning your tether cost is amortized over a relatively small amount of cargo). This means that vacations will be for the well-to-do, and moving out permanently will be for the rich only (you can't build everything you need at the destination until you have a minimum industrial base there, and lifting it there costs money; ditto building a transport to the moon or to Mars or the asteroids or Lagrange colonies).
In short, people as individuals won't benefit from space travel unless there's a business benefit. So far, there isn't a good enough case to say one exists, so it's staying in the national prestige contest arena.
In fact the last number I quoted before this thread was $0.45/kwh, which came from Googled material via "Price-Anderson Act" (which was in the news less than a year ago having been up for renewal) relating to an actuarial bid from Lloyds of London, quoted was during the Chernobyl era. Granted, however, that it has been a long time since any commercial insurance company was asked to bid on a nuclear power coverage policy.
I suspect that the number would be significantly lower in Ontario (and likely the rest of Canada), given that we've had a total of two accidents (pipes bursting) over the course of our entire nuclear power program, resulting in zero release of radioactive material to the environment and zero deaths/injuries. There was a release of heavy water containing trace amounts of tritium at one point too, but even near the plant the amount was well below internationally defined safe levels (by about a factor of 10).
The fact is, until the market is asked to bear these risks, instead of the taxpayers, nobody will know how much it costs to insure nuclear electricity. $0.20/kwh is a guess, not a quote.
My objection is to this "guess" being put forth as fact, and used in a costing analysis. The current insurance cost for nuclear risks has been zero, as there have been no payouts in decades of operation.
Insurance not related to nuclear exposure (e.g. insurance against damage to the plant and so forth) is already handled commercially in Ontario, and so already a part of the cost of power.
In summary, the cost at which nuclear power is sold in Ontario has, over the past several decades, has been a reasonable approximation of the cost required to produce it, including costs resulting from liability for accidents.
I'm tired of people ignoring the background proliferation issues.
These proliferation issues are utterly irrelevant to a discussion of how much nuclear power costs to produce relative to other power generation methods.
Correct me if I am wrong, but Canada provides government-sponsored insurance to nuclear facilities just like the U.S. does. My understanding is that if nuclear plants were forced to obtain market rate insurance, the cost of nuclear power would be very much over $0.20/kwh.
You keep throwing this number around, but have yet to provide any source or justification for it.
In Ontario alone, that would amount to $13 _billion_ annually (half of our power generation is nuclear). That would be kind of noticeable in the budget.
Nanomanufacturing could create perfectly spherical containment vessels.
a) Containment vessels for magnetic confinement fusion are toroidal (or variants thereof), not spherical.
b) Precise containment vessel geometry doesn't much affect stability. Plasma turbulence causes stability to degrade. Hence, the active compensation mechanisms that were played with in recent memory.
Please read any of the available FAQs on magnetic confinement fusion.
"These micro-engines have over 300 times more energy than an ordinary battery and are much lighter and smaller."
So a cellphone that needs a daily charging will now need a refill once a year?
I would wager that this claim carries a degree of exaggeration.
The 300x almost certainly refers to energy density (per unit mass or per unit volume; pick one). This is consistent with switching from batteries to chemical fuels (though still a bit optimistic). The thing is, a fuel cell will do the same thing with _zero_ moving parts, instead of the one-moving-part micro-turbine, or this very complicated engine.
Look forwards to refilling your cell phone about once a month when fuel cells are integrated in production models (prototypes have existed for a while now). Both fuel cells and micro-turbines have problems with heat generation, though.
The problem with fusion is not materials. You cannot get a material that will contain a fusion reaction - instead they use magnetic containment. And the problem is keeping the thing stable. I cannot see how nanotech devices would assist in this.
Better materials would help substantially with magnetic confinement fusion. In particular, something with a high tensile strength and a superconductor with high breakdown field strength would make many of the difficulties with magnetic confinement fusion magically go away. Higher field strength helps a *lot* (improving both density and confinement time).
I agree that nanotechnology is unlikely to help with this.
GM organisms could be dangerous if deliberately built to be, but that's about it.
s/organisms/animals/. It's late.
I personally would be extremely cautious with this issue on a level similar to the moral dilema of cloning humans. We don't even understand most of the genetic code of our own species, how the genes interact, or even what they're there for, and we intend to do direct manipulation of genes?
You do realize that the whole point of a clone is that the genetic material _isn't_ changed, right?
The real reason why human cloning is presently a bad idea is that 99 out of 100 clones will _die_ because our current techniques are lousy. Given a perfect technique, cloning ends up being in-vitro fertilization that gives you a twin 20+ years younger than you are. Where's the problem?
Given that biological life has this tendancy to mutate, how do we know what effect this genetic manipulation would have in 2 generations? How about 5? Or 10?
The same argument applies to all life. As we presumably don't worry about our non-engineered house pets mutating into monsters, I wouldn't worry too much about mutation affecting GM organisms.
There _are_ good reasons to be worried about GM foods, but you haven't listed any of them yet. It will be entertaining to see if you get around to citing them or not. GM organisms could be dangerous if deliberately built to be, but that's about it.
Of course, for $20 million a person, you could launch 7 people - the compliment of a shuttle - for $140m. The average shuttle flight costs $500m.
That's the complement when they're hauling cargo too. Keep the cargo, and the fare for the cargo covers most of the launch cost. Lose the cargo, and you can put a passenger/life support module into the cargo bay and carry more passengers.
The grand assumption is that you can find enough people willing to pay $20M for a week in space to make this profitable on the long term, however. I think you'd run out of $100M-ares pretty quickly.
1970's-1990's - Here is where transportation advancement largely drops off. We've gotten more efficient jets. Rocket technology hasn't gotten any better. Cars have gotten more efficient. Other than some efficiency tweaks, we haven't advanced much at all in transportation since the exceedingly rapid advancements of the mid 20th century.
We've actually gotten off our tails and put ion drives and other electric thrusters into production and (semi-) widespread use. Any time you see "Hall effect thruster" in a satellite's description, that's an example of relatively recent space engineering doing its job.
Groundside, we've had steady improvement of fuel cell technology over the past several decades, which has reached the point where fuel cell powered electric devices from cell phones to cars are becoming practical (several prototypes to date). Unlike battery power, the energy storage density of fuel cell systems is comparable to that of gasoline, so we might actually see zero-emission vehicles in the near future. (Yes, emissions happen if you use fossil fuel plants to generate hydrogen or methanol, but you can put _scrubbers_ on a power plant, and change energy production methods in the power grid more easily than change all of the cars on the road.)
Lastly, bear in mind that all technologies peak after a while. The reason cars today look a lot like cars 50 years ago is that the fundamental design is pretty _good_. Many details change, and many incremental improvements are made, but the lack of a radically different design suggests that, over the time in question, a radically better option didn't exist.
Then I learned what you mentioned about it not being a data specification...and it was totally lost on me why XML is of any value whatsoever.
I'm using it for some of my own projects because of the XML parsing libraries. I'll often be using configuration or data files, and it's a pain to have to write a parser each and every time.
YMMV. I consider it a useful, if over-hyped, tool.
What is open? Are you serious? There is a simple and well-layed out spec for HTML, XML, TCP/IP, etc, etc. Use them to spec and don't allow perversions that intentionally break intercommunication/interoperability.
XML is not a data format specification - it's a framework within which data format specifications can be built. Convert documents, spreadsheets, CAD files, and what-have-you to XML and they will be just as incompatible as ever.
All you need is thrust, lift is just one kind of thrust, the rotating blades of a helicopter, produce a lifting force which is the thrust that lifts the aircraft. Other sources of thrust would work as well [jet engine for instance (yes, modern jets do contain airfoils, but they don't need to in order to be a jet and produce thrust)]
For any craft with less than 1g of thrust, you need wings to provide the lift. This is what my airfoil comment was referring to. Helicopter blades were mentioned as a special case, as they could equally validly be considered wings or a thrust-producing device.
There's a world of difference between a jet engine and a rocket engine.
No, they are both devices that expel matter with a higher momentum than it was acquired at, in the case of a rocket you carry the matter with, and in the case of a jet, you pick it up along the way, fundamentally the same.
A water pistol is also a device that expels a jet of matter with greater momentum with which it was acquired. As I'm sure you appreciate, the engineering concerns with propeller, jet, and rocket engines are vastly different. My point was that the development of the first does not make development of the third a minor feat.
yes there is a drastic difference in the amount of technology required for atmospheric flight and space flight, but it is an evolutionary difference, not a revolutionary difference.
I respectfully disagree, especially since the original context was one of going from propeller planes to spaceflight.
Once manned heavier-than-air flight was demonstrated, going to the moon was pretty inevitable
Um, no.
Flight through the atmosphere with heavy craft and launching something into space are almost completely unrelated problems.
For the first, you need to figure out how airfoils work to produce lift (helicopter blades count in this category), and figure out how to move the air that surrounds your craft to produce thrust. Then there's materials engineering to get the performance to weight ratio nice enough.
For the second, you have to figure out celestial mechanics, and you have to figure out how to build reaction drives that _don't_ use the surrounding medium to move (as you won't have air around you for much of your trip, and it's more of a hindrance than a help at significant speed). Then you have the herculean task of materials engineering and clever craft design required to get an impulse-to-weight ratio large enough to escape the gravity well (or at least have enough delta-v for orbit). If the gravity well was even a little deeper, we wouldn't have been able to do it with chemical rockets at all (though aircraft would still be easy to build).
There's a world of difference between a jet engine and a rocket engine. There's a world of difference between something light and strong enough to glide and something light and strong enough to have a 40:1 wet:dry weight and make orbit. It's not a difference of scale - it's a difference of fundamental type of device.
In summary, please do more research about exactly what's involved in each task before proclaiming that one follows from the other. What actually precipitated _both_ was the industrial revolution, which gave a drastic increase in technology and in materials science.
But here's the point: exploring an icy moon billions of kilometres away with a nuclear-powered spacecraft, which is the topic of the story, will probably not change the global balance of power.
No, but creating the infrastructure and public opinion change that would allow the US military to put fission and fusion reactors into space will affect the balance of power.
Actually, I doubt it. The kinds of reactor used on this style of probe are completely useless as weapons, and require no industry retooling. What you'd have to worry about would be a) warheads in space, and b) _large_ fission reactors in space. Completely different beasts.
Oh, and for all those who believe that we should be designing a manned mission to Mars, let me be perfectly clear:
The only way we will get humans to Mars will be using nuclear propulsion and nuclear power sources(RTGs). Period.
Um, no.
Check out the raft of Mars Direct papers for a description of how to do it with chemical rockets.
Using nuclear (NERVA-style) instead of chemical gave you more payload, but didn't fundamentally change the nature of the task.
RTGs are useless for manned propulsion, because their power to weight ratio is low (despite a high _energy_ to weight ratio). They're useless for _un_manned propulsion too, unless you have a mission time of decades. Past RTG launches have used them to power electronics. The mission the article refers to uses a _reactor_, which is a very different beast than a radiothermal generator (much higher power to weight but much more complex).
The "renewable" energy sources such as Wind, Solar, and Geothermal energy don't have a lot of chance of being particularly useful. However, if they're going to be useful at ALL, people have to recognize that they're only going to be useful in *very specific places*.
That may or may not be true for wind power, but solar power can operate just about anywhere. Unless you're in the land of eternal rain, you'll have more than enough sunny days to generate quite a lot of power. You just need about a week's worth of power storage (probably by building an off-the-shelf fuel cell station next to your solar generator; full-scale fuel cell facilities have been online for a while now).
The energy per unit land area of sunlight is very high (on the order of 1 kW/m^2 at maximum), making the total area required for even a many-gigawatt plant quite small (about the size of the large city it powers; far smaller than the farmland that feeds that city). Before anyone grouses about photovoltaics, the large-scale solar plants to date have used mirrors to heat a working fluid, which then boils water to drive turbines just as a fossil fuel or nuclear plant does.
This is where I think we'll end up going in the long run. Other renewable schemes tend to be site-specific, low power density, or both. Fossil fuel pollutes horribly even with scrubbers and will get gradually more expensive as reserves dry up. Nuclear requires a large investment in the plant, constant maintenance, and is a political nightmare. Solar in various forms can provide power on scales from "personal" to "large city", without much in the way of drawbacks.
The heavily subsidized typical cost for U.S. nuclear power is around $0.12/kwh
[...]
The unsubsidized, fully amortized cost of wind power is about $0.04/kwh.
That's funny, we use nuclear plants for a lot of our power here in Ontario and our cost of power is about 4 cents per kWh *Canadian*.
How about backing up your numbers, instead of cutting and pasting the same rant, hmm?
But you imply something quite scary: Do humans have the right to determine which species ar contributing to the ecosystem, and exterminate the rest? Are we capable of doing this? qualified? What if we make a mistake?
:-)
:). I'm just trying to throw thought-provoking questions at you.
Why would we not have the right to mold the world as we see fit? If we don't, who does, and on what authority are we forbidden from making changes?
I agree that large-scale mucking about may be dangerous for us - we're near the top of the ecosystem, and so in a relatively fragile position - but abstaining from making changes on that basis is a question of prudence, not of "rights".
I believe that it is a better solution to identify the areas we are having the most impact, minimize it, and let nature run its course. Let's not second guess nature. It's done a good job of maintaining things long before we were around...
Nature has no grand plan, though. It's literally a random process, and most definitely doesn't have our welfare in its best interest - it _has_ no interests. If anything, we should expect life to become more difficult for us if we leave it to nature's ebb and flow (we multiplied because there was a favourable environment, but environments change).
In summary, I do not see why nature running unhindered would work towards any human-oriented goal.
On the other hand, this entire debate is rather silly without a set of goals everyone agrees on
QNX is designed like a modern os should be. It's straigt out of an Operating Systems 101 textbook.
If only Linux had more of QNX's design niceties and robustness.
Care to provide details, as opposed to just making vague assertations?
p.s. specialized OS don't crash because it's exactly that - specialized. I think windows crash so much because (part of the reason) it runs on so many kinds of hardware, for one. As much as I will get flamed, in OEM applications, like, say, most of the new fancy I-will-never-be-able-to-affort oscilloscopes and the likes, windows usually don't crash.
The purpose of an operating system is to provide an abstraction layer between the hardware and application software, and between all of the tasks running on a machine. If done right, this prevents most crashing no matter what you're doing (as most software doesn't have the privileges needed to take down the whole system). If done wrong, application software can muck with things it shouldn't, and the whole system comes crashing down when something goes wrong.
Any of the 9x series of Windows, and WinME, fall into the second category. Windows NT (including 2K and XP), and various Unix flavours and clones (including MacOS X), fall into the first category.
While a general-purpose system has more potential points of failure in software - as you're running more software - this is not an excuse for it to be crash prone. A well-protected OS is vulnerable to bugs in the OS core and in the drivers interfacing with hardware, which will for the most part still be there even in a single-purpose system.
In summary, you can't blame windows crashing on it being a general-purpose operating system. There are plenty of general-purpose OSs that crash far less. There are special-purpose OSs that are designed shoddily, as well (it's just easier to catch that before it goes to market, because the test space is smaller).
FWIW, re. another thread, my understanding is that WinCE is a stepchild of NT (heavy rewrite to make it modular and to pare out functionality that isn't needed in embedded systems, while keeping most of the core OS design). That should make its behavior similar to that of NT.
Yes, NASA has launches probes powered by radioactive decay. There's a big difference between that and a rocket with an active nuclear reaction in its engine.
Read the article. This uses an ion drive and a nuclear-electric generator. The concept drawing has these at opposite ends of the craft, so there are no exhaust stream issues.
You could build a craft like this using the same kind of radiothermal generators that have been used in previous missions. This craft specs a power source a hundred times stronger, which means either an RTEG with an isotope that's a hundred times shorter lived, or an induced fission reactor (see below).
What if the rocket blows up?
Any fuel pellets sent up in a space probe will be encased in shells that can survive explosion and re-entry. This is already proven technology, tested for sending up the RTEGs that are already used.
Rocket explodes, fuel pellets land intact in the debris field, fuel pellets are collected by hazmat teams without contaminating the surroundings.
What if it's cold and the O-ring on a control rod cracks, causing the reactor to overheat?
An RTEG is sub-critical - there is no failure mechanism.
If it's an induced fission reactor (the kind that needs control), it'll almost certainly be a self-balancing one like the Slowpoke that has no moving parts (it has to last for decades with no maintenance). You couldn't destabilize a reactor like that if you _wanted_ to, and it requires no active control.
The way these reactors work is that the support frame and/or the housings for the fuel pellets use a material with a very high rate of thermal expansion; turn up the heat, and the fuel pellets move farther apart, shutting down the reactor - it balances just on the edge of shutoff.
Damage it, and at worst you break it up, causing instant shutdown (there's no longer enough material in one place for criticality).
What if the launch has to be aborted before the rocket has reached orbital velocities and the reactor has to fall to earth?
Then the rocket is detonated, and you have the same thing happening as with a rocket explosion - several dozen radioactive marbles, intact, littering the landscape.
In summary, your objections are puzzling at best.