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Well, you learn something new every day. Or at least I try to.

CO2 poisoning

KFG

Don't forget, a 1000MW coal plant releases 88 lbs of radioactive stuff every day.

Coal plant, living within 50 miles: .03 mrem
Nuclear plant, living within 50 miles: .009 mrem
(Both figures are considered extremely low levels.)

As far as the claim, "Every fast-neutron sodium reactor design ever built has had some serious accidents related to sodium," this is false.

Let's see: The Seawolf had a sodium accident. The Lagoona Beach reactor had a block of the sodium channels and a partial meltdown. The Phoenix reactor had sodium problems. So did the Soviet BN-300 and BN-600 reactors. Even the Soviet Rorsat reactors (Na-K eutectic) had leaks. Of course, every light-water reactor ever built has leaks too. The difference is that when sodium leaks you have a fire, when water leaks you don't.

Unfortunately this fails to take into account the amount of spent fuel sitting in pools at nuclear plants. This is fuel as well and still retains approximately 98% of its energy potential.

Yes, but all the reactor fuel ever spent only amounts to less than 50 years' worth of power. So even if you can use the remaining 98%, that's only 2500 years. Hardly "all of human history". And that's ignoring growth in energy consumption, as well as inefficiencies in the process. Both of which will drastically reduce the estimate. You are rather stuck - if the fraction of total energy available from spent fuel is large, then that implies that there isn't much more available to be mined. In any case, fission energy resources are not sufficient to power current society for more than a few thousand years. Humans have existed for >100,000 years.

As far as plutonium goes, the plutonium that is most useful to power generation (the heat-generating isotopes) are precisely the kind of plutonium you don't want for weapons...[]spent fuel from a nuclear reactor designed solely for power generation has never before been used by any country to make a nuclear weapon

I understand the difference between Pu-240 and Pu-239. However, the fact that it hasn't (officially) been done in no way proves that it can't be done. It's mostly a matter of implosion speed, and if you are willing to accept a fizzle, it's not even that hard. A fizzle will still be a very powerful dirty bomb, and would cause a huge disruption to any metropolitan area so hit. With modern implosion designs it is quite likely that you could get a very significant yield from IFR plutonium; imagine what a 1kt explosion in downtown Manhattan would do.

There are two issues related to non-proliferation. The first is terrorism, the second is states acquiring nuclear weapons. In the first case, terrorists would be very happy to have IFR-grade plutonium even for just a dirty bomb (the Pu-240 actually makes it more of a problem). As far as states acquiring nuclear weapons - an IFR gives them access to a neutron source suitable for blanket breeding (note that blanket breeding can produce any grade of Pu you wish, including very low Pu-240-content stuff). It also gives them the technology for isotope separation, since as you point out, the plant also contains a separation facility. That can hardly be good. It's a nasty tradeoff: if you centralize the separation/recycling then you have fuel and plutonium transports that are vulnerable to terrorism. If you move the separation out to the plants then you are giving sensitive technology to potential proliferators. Either way you're inviting trouble.

This reminds me of a physics qualifying exam problem. If you fire your rockets on the nuclear-waste cargo ship straight toward the Sun and then coast, from Earth it would look like the ship heads toward the Sun, starts to veer to the right (if North is up), and follows a circular path that leads it right back to the Earth 1 year later. It's just like that boomerang that comes around and hits Wile E. Coyote in the back of the head. (This is ignoring Earth's gravity.)

As others pointed out, you have to cancel the orbital motion. I wonder if solar power or solar sails could be used to do this?

A google search turned up this discussion. Here people point out that it is cheaper to send the waste anywhere _but_ the Sun. I like the idea of putting it in orbit. Crashing it into Venus of Jupiter seems like it might impact future science missions to those planets by introducing foreign substances to some very minor degree. They also point out that politics is the main problem, not cost. Another significant problem is that of disasters during launch. It's hard to imagine a launch system that is both cheap and has an acceptable failure probability. Would 1 in 1 billion be good enough for you? I don't know, probably not for me.

Remember most people at MCDonalds don't own a laptop, and if they do, they dont take it with them when they are eating.
And this case says it all about the intelligence of the average McDonalds customer.

I haven't read this book, and I'm not sure I want too, because it seems to be overkill. Bicyclists in search of a practical, down-to-earth analysis of the bike might check out the prodigious writings of Jobst Brandt, a mechanical engineer and avid touring rider. Brandt eschews quantum mechanics and other irrelevancies and instead analyzes and explains the real problems of bicycles. Most notably, Brandt published The Bicycle Wheel, the definitive text on the function, response, and building of spoked wheels. I used it to select parts for and to build my current wheels and let me tell you, building your first set of bike wheels is even more interesting than building your first PC.

Brandt is a tourer of some note. His Alpine and Sierra Nevada tours are legendary and have inspired a lot of cyclists.

You can access and search Brandt's writings via USENET: try looking at rec.bicycles.tech.

Hand grenade, don't know, but a nuclear bazooka does (or, at least I hope, did) existe: the Davy Crockett.

Some info on what this hideous piece of equipement was capable of is here.

Additional info can be found here

Yes and no.

I found this interesting thread having some interesting helium facts.

Helium is a finite non-renewable resource, as it does eventually escape the upper atmosphere.

But keep in mind that Texas is not the only place natural gas is found. There are significant reserves in the middle east as well (and the source of much argument as to how much we should import, the prices are rising for it in the US).

The helium that came from when the earth was formed has gone, and the helium we have today comes entirely form radioactive alpha decay in rocks. Thus the amount of helium in natural gas in any given area is variable.

Also, natural gas is not the only potential source for helium, as it exists in other places. It could conceivably be fractionally distilled from the atmosphere (and it was initially, read the link above), though this would be costly. Also, helium could be produced in nuclear reactors.

In the end, helium is a commodity, like many other things. As such, it follows fundamental market forces and the laws of economy. Demand for helium thus determines the price for helium (mostly, there is some government influence that comes into play through regulation, but that is beyond the scope of this post).

So, if for some reason they could not produce helium in Texas (unlikely) or for some reason there was shortages for helium due to demand, the price would go up. This would lead to higher prices, and people would start to look for other sources. Foreign producers would be motivated to produce helium. If it was expensive enough, conservation would take place, and where it was possible, other substances/methods would be would be used (like in welding, they would use argon instead of helium. In fact many do already as it is cheaper). Interestingly, a large part of the cost of helium is the shipping of it around in the big heavy metal tanks. That's why they may use argon in this acoustic fridge rather than helium.

Instead of using helium in party ballons, hydrogen (possibly mixed with air to reduce flammability) could be used. While some may see this as dangerous, it would be a lot less dangerous than the flammable silly string used in many a party. But I digress. You get the idea.

But I do think that this calls for a sense of perspective. We live in a world with limited resources. From gold to oil to water to food even (it could be argued) clean air.

So, as you can see, the chance of a Texas monopoly on helium is slim. Your second statement, that alternate sources would be found (and don't forget substitutions made) is more correct.

Helium scarcity is a physical reality, but it also obeys the laws of economics.

There exists a shape which can move supersonically without generating a shockwave. On the outside it is a smooth cylinder. Internally it is equipped with a carefully shaped intake coupled to an expansion nozzle that compresses the air as it passes through and expands it back to its original pressure without generating a discontinuity in pressue (i.e. a shockwave).

A sniper bullet was developed (in the 60s, IIRC) that uses this shape. The idea was to give the sniper a second chance if the first bullet misses. The supersonic shock of the passing bullet is generally what alerts the target. The muzzle noise is distant and can be silenced quite effectively.

The only problem with this shape is that it is symmetrical and therefore cannot produce any net lift. This would seem to make it impossible to build an airplane using this concept. In fact, it only means that a shock-free unpowered hypersonic glider is impossible. A powered airplane could theoretically use the engine's energy to offset the required asymmetry and have thrust, lift, supersonic motion and no shockwave all without violating the laws of aerodynamics. Actually designing such an aircraft is still a monumental task and there is no guarantee that a practical solution can be found - but in principle it should be possible.

Note that the methods described in the article are supposed to soften the shockwave as it propagates away from a conventionally-shaped aircraft while this is about odd shapes for canceling it at the source.

See this discussion for more details.

One of the best places to look for anything is at or near the bottom of a well

Ha! Unless its helium you're looking for!

Oh, wait..Crap!

After all, the ringworld is unstable.

• Migma fusion
• Inertial electrostatic confinement
• Muon-catalyzed fusion
• Antimatter-catalyzed fusion
• Cold fusion

[Maglich]'s grant-proposal was rejected, not on its technical merits, but because ERDA had already made a policy decision that only the Tokamak and Laser-Inertial-Confinement approaches should be funded. Migma was erroneously classified as a magnetic mirror machine, and ERDA had decided to phase out mirrors. When Maglich tried to appeal this decision, the Gov't-convened Robson commission did a railroad-job on him ( twelve tokamak-experts read twelve prepared negative statements, with no opportunity for rebuttal). A colleague of mine let me read copies of the Robson report and FEC's response; the Robson commission's misunderstanding of the principles behind migma was very distressing...)

You speak the truth there, friend.

Apparently, water is a good agent to start a ClF5 fire...

T&K.

Also, keep in mind the fact that insects and rodents can't seem to resist those tasty tasty wire casings. There may come a time when some segments fail inexplicably.

Good point. You should definitely keep sharks out of your conduits.

Secondly, doing a few financials on this thing you can see there is a good reason to spend the money in other ways to lower low-earth orbit costs:

Let's say you, through some kind of miracle of government subsidy or making space as sexy to billionares as philanthropy to Africa, manage to get $10 billion at only 12% interest for this high risk project. Further lets say the miracle is so wonderful that you don't actually have to pay any interest on any of that money for 10 years while you are getting the elevator operational. (I forgot to mention the miracle that lets you actually construct the whole thing at all since the article admits they can't with carbon nanotubes as currently engineered.) Finally, lets say you miraculously only have to pay the interest on the principle once the whole thing is running. OK, so we're looking at a mere $100 million per month interest payments.

Are there any other lower risk ways of spending $10 billion that yield 12% interest? Lots, of course, but since we're being miraculous here we can assume we can grab the $10 billion and put it in one of those 12% yield bonds or mutual funds or whatever and have $100 million per month without spending the principle.

So what do you do with $100 million per month to, over the course of 10 years, get a system in place that can reach low earth orbit for $100/lb?

Lots of things, not the least of which is just guarantee a market for for launch services of $100 million per month for the next 10 years for any mass launched into orbit that doesn't end up as orbital debris. You pay only by the pound and you divide up the money evenly, each month, between all mass launched from earth to orbit that month.

The result is a "race to the bottom" in terms of cost/lb to earth orbit.

Where does it limit out?

Fuel costs aren't the limiting factor.

How about the vehicles?

Well, the vehicles don't have to be all that expensive really. Control electronics? Naw. Tankage? Take for example the mass production of Coke bottles out of PET plastic. These are tough, light-weigh bottles capable of withstanding cryogenic temperatures. Do something in quantity and you can get the prices of pressure bottles way down. Engines? The guys who worked on the Atlas engines in General Dynamics told me they weren't really any more close-tolerance than the VW engines you put in your old '69 microbus. Again, volume is the key. Rocket science ain't rocket science. The key is industrial production and operational volumes.

So at the end of 10 years, what you have are a bunch of small companies doing the equivalent of a Latin American VW factories cranking out disposable rockets (the tankage, electronics and engine metal for which you can use on orbit anyway so your effective payload is quite a factor), launching a million pounds per month into orbit at $100/lb.

As others have said, shutting down solid fuel rockets is difficult. But it's not impossible. See here:

You can shut down most solids by blowing open vents in the casing, because modern solid fuels don't burn well except at high pressure. In fact, most solid-fuel ICBMs do shut down their solid stages that way, to minimize trajectory errors.

The shuttles don't do this because it's too violent, as the SRBs are right next to the tank and the orbiter's wings. But if you could do this reversibly in space, it might be possible. You would need to be a pretty big valve. Or maybe you could just dialate the nozzle.

Stacking many small solid fuel engines could also be helpful. If the mission design is such that energy is more important than power, it might be useful. It might also be more reliable than one big liquid fuel rocket - if one doesn't light, just jettison it and light the next. (As long as it never explodes, and the top of the stack could take the compression.)

And how exactly is this relevant to the subject at hand? Answer:

I am so sensible, Sir, of the kindness with which the House has listened to me, that I will not detain you longer. I will only say this, that if the measure before us should pass, and should produce one-tenth part of the evil which it is calculated to produce, and which I fully expect it to produce, there will soon be a remedy, though of a very objectionable kind. Just as the absurd acts which prohibited the sale of game were virtually repealed by the poacher, just as many absurd revenue acts have been virtually repealed by the smuggler, so will this law be virtually repealed by piratical booksellers. At present the holder of copyright has the public feeling on his side. Those who invade copyright are regarded as knaves who take the bread out of the mouths of deserving men. Everybody is well pleased to see them restrained by the law, and compelled to refund their ill-gotten gains. No tradesman of good repute will have anything to do with such disgraceful transactions. Pass this law: and that feeling is at an end. Men very different from the present race of piratical booksellers will soon infringe this intolerable monopoly. Great masses of capital will be constantly employed in the violation of the law. Every art will be employed to evade legal pursuit; and the whole nation will be in the plot. On which side indeed should the public sympathy be when the question is whether some book as popular as Robinson Crusoe, or the Pilgrim's Progress, shall be in every cottage, or whether it shall be confined to the libraries of the rich for the advantage of the great-grandson of a bookseller who, a hundred years before, drove a hard bargain for the copyright with the author when in great distress? Remember too that, when once it ceases to be considered as wrong and discreditable to invade literary property, no person can say where the invasion will stop. The public seldom makes nice distinctions. The wholesome copyright which now exists will share in the disgrace and danger of the new copyright which you are about to create. And you will find that, in attempting to impose unreasonable restraints on the reprinting of the works of the dead, you have, to a great extent, annulled those restraints which now prevent men from pillaging and defrauding the living. - Mr. Serjeant Talfourd

I think that thoroughly covers the connection I'm making.

CISC processors tend to have smaller code size, even if the execution units are similar. You can think of this as CISC having a decompression engine between icache and the execution units. When main memory is slow and far away, reducing the amount of memory needed for code can be helpful, especially in modern (bloated?) systems with zillions of bytes of shared libraries loaded.

Here's a ref to a discussion of RISC's response to this problem.

Yup, this is one of my two faves. The other one is the lunar orbit coinciding perfectly with the lunar rotation, so that the same side of the moon always faces Earth.

In general, most Unixes and Linux (as you say) have adopted the LP64 model where longs/pointers are 64-bits and ints are 32 bits (some gory details here. (Cray's Unix is an exception; it's ILP64).

Windows OSes however have adopted the LLP64 model where ints and longs are 32-bits still, but long longs and pointers are 64-bits (gory Windows details here and here.)

Both 32-bit Windows and Unix traditionally used ILP32, so the porting characteristics moving to 64-bit code are slightly different across the two platforms.

--LinuxParanoid

and here's a somwhat older story about the perils of applying for a security clearance from risks.d http://yarchive.net/risks/mongrel.html

text of the com of UAL232 prior to landing in Sioux City, video

I didn't know who wrote the first one, but I'd written one in I believe the fall of 1984 (could have been that winter). Not that I thought I was first, but it was at least pretty early. Nobody had heard the words "computer virus" before, and I certainly didn't use them. I called it a "self-replicating program." In my version I hooked the command interpreter for Apple DOS's "catalog" command and made it copy itself in place on whatever disk it was looking at. Simple and effective -- and benign, since all it did was replicate (although a few variants did more amusing things like change the catalog output subtly).

I knew that was pretty early, but it turned out that there were at least two earlier viruses on the Apple -- both done at colleges circa 1982. The only one I remember was done at I think Texas A&M, and IIRC theirs were substantially more sophisticated than mine.

Oh look, Google even knows about the Texas virus:

http://yarchive.net/risks/early_virus.html

It seems to be the pumping efficiency that's the advance.

Good. Scale this up or just replicate it a couple of thousand times, and there's our launch base, capable of pipelining a 25-50 kg package into orbit once per 10 minutes.

For extra points, the article might have included some physical measurements and a power comparison with gas lasers, which I believe are around 10 megawatts.

A taste of the discussion from a few years back, which did mention that diode-pumped solid-state lasers were coming on:

Here

Goodwill

A SPEECH DELIVERED IN THE HOUSE OF COMMONS ON THE 5TH OF FEBRUARY 1841


"I will only say this, that if the measure before us should pass, and should produce one-tenth part of the evil which it is calculated to produce, and which I fully expect it to produce, there will soon be a remedy, though of a very objectionable kind. Just as the absurd acts which prohibited the sale of game were virtually repealed by the poacher, just as many absurd revenue acts have been virtually repealed by the smuggler, so will this law be virtually repealed by piratical booksellers. At present the holder of copyright has the public feeling on his side. Those who invade copyright are regarded as knaves who take the bread out of the mouths of deserving men. Everybody is well pleased to see them restrained by the law, and compelled to refund their ill-gotten gains. No tradesman of good repute will have anything to do with such disgraceful transactions. Pass this law: and that feeling is at an end. Men very different from the present race of piratical booksellers will soon infringe this intolerable monopoly. Great masses of capital will be constantly employed in the violation of the law. Every art will be employed to evade legal pursuit; and the whole nation will be in the plot. On which side indeed should the public sympathy be when the question is whether some book as popular as Robinson Crusoe, or the Pilgrim's Progress, shall be in every cottage, or whether it shall be confined to the libraries of the rich for the advantage of the great-grandson of a bookseller who, a hundred years before, drove a hard bargain for the copyright with the author when in great distress? Remember too that, when once it ceases to be considered as wrong and discreditable to invade literary property, no person can say where the invasion will stop. The public seldom makes nice distinctions. The wholesome copyright which now exists will share in the disgrace and danger of the new copyright which you are about to create. And you will find that, in attempting to impose unreasonable restraints on the reprinting of the works of the dead, you have, to a great extent, annulled those restraints which now prevent men from pillaging and defrauding the living."

" Why would copyright be abolished?"

See: A SPEECH DELIVERED IN THE HOUSE OF COMMONS ON THE 5TH OF FEBRUARY 1841 by Thomas Babington Macaulay

"I will only say this, that if the measure before us should pass, and should produce one-tenth part of the evil which it is calculated to produce, and which I fully expect it to produce, there will soon be a remedy, though of a very objectionable kind. Just as the absurd acts which prohibited the sale of game were virtually repealed by the poacher, just as many absurd revenue acts have been virtually repealed by the smuggler, so will this law be virtually repealed by piratical booksellers. At present the holder of copyright has the public feeling on his side. Those who invade copyright are regarded as knaves who take the bread out of the mouths of deserving men. Everybody is well pleased to see them restrained by the law, and compelled to refund their ill-gotten gains. No tradesman of good repute will have anything to do with such disgraceful transactions. Pass this law: and that feeling is at an end. Men very different from the present race of piratical booksellers will soon infringe this intolerable monopoly. Great masses of capital will be constantly employed in the violation of the law. Every art will be employed to evade legal pursuit; and the whole nation will be in the plot. On which side indeed should the public sympathy be when the question is whether some book as popular as Robinson Crusoe, or the Pilgrim's Progress, shall be in every cottage, or whether it shall be confined to the libraries of the rich for the advantage of the great-grandson of a bookseller who, a hundred years before, drove a hard bargain for the copyright with the author when in great distress? Remember too that, when once it ceases to be considered as wrong and discreditable to invade literary property, no person can say where the invasion will stop. The public seldom makes nice distinctions. The wholesome copyright which now exists will share in the disgrace and danger of the new copyright which you are about to create. And you will find that, in attempting to impose unreasonable restraints on the reprinting of the works of the dead, you have, to a great extent, annulled those restraints which now prevent men from pillaging and defrauding the living."

I keep seeing quotes like these. Admittedly, there are some negative points about current rockets (which I intend to fix!), but the underlying approach is not really that bad.

Modern, well designed rockets can achieve 90% efficient conversion of chemical energy into kinetic energy. (Please see http://yarchive.net/space/rocket/efficiency.html.

Now, that is not currently achieved by the Space Shuttle SRBs, for example, but an example of a bad design does not make a good design impossible.

The safety issuses can also be addressed. Remember the report on parrafin wax burning as rocket propellant? Ever seen a candle explode?

Just some thoughts!

I think you'll like this:

A SPEECH DELIVERED IN THE HOUSE OF COMMONS ON THE 5TH OF FEBRUARY 1841 by Thomas Babington Macaulay

Here's the best part: "I will only say this, that if the measure before us should pass, and should produce one-tenth part of the evil which it is calculated to produce, and which I fully expect it to produce, there will soon be a remedy, though of a very objectionable kind. Just as the absurd acts which prohibited the sale of game were virtually repealed by the poacher, just as many absurd revenue acts have been virtually repealed by the smuggler, so will this law be virtually repealed by piratical booksellers. At present the holder of copyright has the public feeling on his side. Those who invade copyright are regarded as knaves who take the bread out of the mouths of deserving men. Everybody is well pleased to see them restrained by the law, and compelled to refund their ill-gotten gains. No tradesman of good repute will have anything to do with such disgraceful transactions. Pass this law: and that feeling is at an end. Men very different from the present race of piratical booksellers will soon infringe this intolerable monopoly. Great masses of capital will be constantly employed in the violation of the law. Every art will be employed to evade legal pursuit; and the whole nation will be in the plot. On which side indeed should the public sympathy be when the question is whether some book as popular as Robinson Crusoe, or the Pilgrim's Progress, shall be in every cottage, or whether it shall be confined to the libraries of the rich for the advantage of the great-grandson of a bookseller who, a hundred years before, drove a hard bargain for the copyright with the author when in great distress? Remember too that, when once it ceases to be considered as wrong and discreditable to invade literary property, no person can say where the invasion will stop. The public seldom makes nice distinctions. The wholesome copyright which now exists will share in the disgrace and danger of the new copyright which you are about to create. And you will find that, in attempting to impose unreasonable restraints on the reprinting of the works of the dead, you have, to a great extent, annulled those restraints which now prevent men from pillaging and defrauding the living."

Well, this doesn't go back quite that far...

A SPEECH DELIVERED IN THE HOUSE OF COMMONS ON THE 5TH OF FEBRUARY 1841

by Thomas Babington Macaulay

On the twenty-ninth of January 1841, Mr Serjeant Talfourd obtained leave to bring in a bill to amend the law of copyright. The object of this bill was to extend the term of copyright in a book to sixty years, reckoned from the death of the writer.

On the fifth of February Mr Serjeant Talfourd moved that the bill should be read a second time. In reply to him the following Speech was made. The bill was rejected by 45 votes to 38.

Though, Sir, it is in some sense agreeable to approach a subject with which political animosities have nothing to do, I offer myself to your notice with some reluctance. It is painful to me to take a course which may possibly be misunderstood or misrepresented as unfriendly to the interests of literature and literary men. It is painful to me, I will add, to oppose my honourable and learned friend on a question which he has taken up from the purest motives, and which he regards with a parental interest. These feelings have hitherto kept me silent when the law of copyright has been under discussion. But as I am, on full consideration, satisfied that the measure before us will, if adopted, inflict grievous injury on the public, without conferring any compensating advantage on men of letters, I think it my duty to avow that opinion and to defend it.

The first thing to be done, Sir, is to settle on what principles the question is to be argued. Are we free to legislate for the public good, or are we not? Is this a question of expediency, or is it a question of right? Many of those who have written and petitioned against the existing state of things treat the question as one of right. The law of nature, according to them, gives to every man a sacred and indefeasible property in his own ideas, in the fruits of his own reason and imagination. The legislature has indeed the power to take away this property, just as it has the power to pass an act of attainder for cutting off an innocent man's head without a trial. But, as such an act of attainder would be legal murder, so would an act invading the right of an author to his copy be, according to these gentlemen, legal robbery.

Now, Sir, if this be so, let justice be done, cost what it may. I am not prepared, like my honourable and learned friend, to agree to a compromise between right and expediency, and to commit an injustice for the public convenience. But I must say, that his theory soars far beyond the reach of my faculties. It is not necessary to go, on the present occasion, into a metaphysical inquiry about the origin of the right of property; and certainly nothing but the strongest necessity would lead me to discuss a subject so likely to be distasteful to the House. I agree, I own, with Paley in thinking that property is the creature of the law, and that the law which creates property can be defended only on this ground, that it is a law beneficial to mankind. But it is unnecessary to debate that point. For, even if I believed in a natural right of property, independent of utility and anterior to legislation, I should still deny that this right could survive the original proprietor. Few, I apprehend, even of those who have studied in the most mystical and sentimental schools of moral philosophy, will be disposed to maintain that there is a natural law of succession older and of higher authority than any human code. If there be, it is quite certain that we have abuses to reform much more serious than any connected with the question of copyright. For this natural law can be only one; and the modes of succession in the Queen's dominions are twenty. To go no further than England, land generally descends to the eldest son. In Kent the sons share and share alike. In many districts the youngest takes the whole. Formerly a portion of a man's personal property was secured to his family; and it

Solar has a large energy investment and the panels, batteries etc are hard to recycle. Oil and coal are environmentally devastating in production as well as use (our largest local (Muja) coal station burns 12 tonnes a year of uranium, to say nothing of releasing radon etc); gas is better but shipping all of those big bombs around the country's just gotta have a sudden, loud environmental impact one day, hopefully not near any serious population. Wave and tidal generators muck around with the local ecosystem something chronic (as does Ocean Geothermal, but if you integrate fish-farms you at least get roughly twice the industry for the same amount of intervention). Nukes are quiet, clean, low-profile and produce small amounts of straightforward-to-manage waste.

If we were allowed to build proper nuclear rockets as well (get Burt Rutan to design them, not NASA), we could fling hundred-tonne loads of waste into the sun (or better still store it in a safe place (orbit/moon etc) for later re-processing) for an extremely low environmental cost. This is a question which has been studied to death, the answers are all to hand.

Stand by for a flock of "-1, Outrageous" mods from people who call themselves "green" but never actually think about the issues. They drive old, cheap, smoky, polluting cars and track dieback through the native forests they claim to protect. Here's a better way of approaching these things.

What if a volcano blasts a mountain of uranium into the air? What if your nearest coal-burning power plant releases 13 tons of uranium and thorium a year?

archive of comp.os.linux.advocacy

Go to the link -- it's good.

Ever handled the tile material? I have. They had a neat demonstration where they heated a cube of it cherry-red with a torch and then handed it around a moment later. Incredible material, light and essentially fireproof.

But also brittle and fragile as hell, comparable to styrofoam or balsa wood. I've handled this stuff and it would have been trivial to damage with my bare hands. Armor against a blowtorch, but not a pebble.

NASA apparently has had a number of incidents involving damage to the belly of the orbiter from separated insulation and ice on launch. Apparently the polyurethane (or whatever it is) can become ice-impregnated, too, with the hardness of a brick. The report I read reported that on one occasion 300 tiles were damaged beyond repair, and that tiles had been sliced as deep as 1 1/2" out of 2" -- "enough" for re-entry, but there's always the next time. Perhaps Columbia was that next time and your random chance came up.

There have only been a bit over 100 missions, and the composition of the foam has changed over time -- perhaps also the tiles? Yes, the Shuttle was designed for brutal re-entry, but not to HIT anything at supersonic speeds. The tile would be destroyed by mere rain. Apollo by contrast launched in just about anything. Apollo 12 even survived a lightning strike (barely -- the capsule guidance system was scrambled, which would have led to a breakup of the launch vehicle had it not had its own redundant guidance).

I'm unwilling to draw any conclusions this early, but the damaged-tile theory is plausible. If we're lucky we'll recover that wing.

You're totally right, except maybe on the Wallpaper thing (I use a Mac and we called them "Desktop Pictures" first -- what the heck is this "wallpaper" thing anyway? It's a desktop, not a wall. :) I thought of Voyager later. A lot of Voyager was overshadowed by the Shuttle, both its successes and, directly, the Challenger catastrophe.

Viking had more of that "defining moment" quality with the actual landings (two!). The idea of these robotic human-designed craft setting down on MARS was amazing to me in a way I suppose Apollo touchdown to have been. I thought the Pathfinder "hard landings" were cheating a little. :)

Yet I don't have any real interest in sending humans to Mars, not because I'm older and wiser but because the inefficiency and mortal risk are just too huge for a "gee whiz" moment. Apollo can be described uncharitably as a "stunt" -- a damn cool one but also a damn lucky one for loss of life. Apollo 13 wasn't the only close call; Apollo 12 avoided total breakup when it was struck by lightning because of accident of design. Look at the extremely expensive double failure in 1999 -- at least no one was killed. Even NASA's unmanned plans for Mars are stumbling badly.

Voyager -- that those things are still functioning 25 years later! -- and doddering Galileo -- also well past its design life -- are what draw my attention. The brilliant Galileo tape recorder repair is mentioned here.

Manned spaceflight, specifically the Moon landing, is an amazing accomplishment that will always symbolize so much, but it can't compete now with the performance of the engineers in these ingenious probe projects. I don't want the the program gutted, I want it refocused and improved with modern sensibilities adn technologies.

Even ISS can be serviced mostly by "dumb" rockets, as was Mir, if we must go the route of a space station. (Yes, the Mir resupply vehicle had a fender-bender, but humans could have done that, too.) The shuttle's role there has been overemphasized so that the shuttle would have a role as all.

Otherwise, why would you be posting articles under purposefully misleading titles such as "Doom For the SonyEricsson P800 smartphone"?

Look what happened to MIPS after a headline was published about the slide of Mips ratings as a viable performance indicator.

You must be one of those Illuminati dudes or something.

T&K.

About Galileo, some tales from several years ago, mentioning the current tape problem.

I would like to hear what exactly the engineers did. I have a feeling it was the interplanetary version of whacking your TV set to stop the whine.

Not all twiddle-the-computer exercises work out well. NASA is not one to dwell on failure, but they'll hand-deliver a press release to your door for great news. E.g., I read that contact with one of the Viking landers was lost years ago after someone sent bad data to its antenna tracking system. The lander was very late in its lifespan, but would you like to have been the guy who did it? We've found reasons to keep in touch with even the Voyagers (or should I say V'gers?), as well as the nearly 4x too old Galileo.

The Web is so cool: Galileo's current position

And Galileo tour guide -- the Galileo stuff at the NASA site is a little dusty. :)

Should we have a moment of silence with spunky Galileo burns up? Do you think the Jovians will retaliate?

On the other, they're expensive as hell, after 30 years of flying they're only just now looking like they're even close to getting them fully reusable (does it count if you have to remove them and tear them apart after each and every mission 'just to check'), and contrary to what NASA will tell you they aren't the only reusable engine out there (other engines aren't classed as such, mainly by NASA, but have had >2,000 seconds on them during testing, and that's about the same as most of the shuttle engines have, only the other engines probably need less maintenance.)

Oh yeah and they burn hydrogen. Hydrogen gives great exhaust velocity, but it's really seriously not very dense. This makes the tanks, fuel lines, and pumps much heavier, (that external tank costs $100 million, oh yeah and they throw it away each time).

Current thinking is that LOX/LH is about 6% worse overall than LOX/Kerosene for getting to orbit- the rocket needs more delta-v due to the extra vehicle weight and other technical issues and that swamps the extra performance of the hydrogen; oh yeah and LOX/Kerosene may not have needed an external tank to be thrown away because Kerosene is much denser.

All in all. Hey, it works! Anyway, pass the popcorn someone; it's still a rocket engine, and it makes a loud noise. ;-)

Thanks -- looking back I realized I was too critical. After all, they were doing 1000's of things for the first time, especially life support.

I later looked this up at this archive, which suggests what you said: The key error (in retrospect) was the use of O2 on the ground. Mercury was ground pressurized with plain air. Another criticism I read somewhere is that the astronauts themselves introduced netting and velcro to store things in the cockpit, and these burned very quickly indeed.

ANYWAY ... was this a hardware fault or design failure? Hmm. Well, we're off-topic anyway.

Many people seem to believe this myth that halon removes oxygen from the air, and that it is deadly to humans. It's simply not true.

A fire requires three things: fuel, oxygen, and heat. A fire can be stopped in four ways: by removing fuel (e.g. shutting off a gas tap), by removing oxygen (e.g. smothering in CO2 or a fire blanket), by cooling (e.g. with a water hose), or by interrupting the chemical reaction. Halon is an example of this last strategy.

If you wanted to exclude oxygen from the machine room, the most economical and effective approach would probably be to dump CO2 into it. (This is why most office fire extinguishers use CO2 -- it works nicely on small fires and is safe around electrical equipment.) The problem is that in a confined space this would also asphyxiate any humans. (As another example of a confined space containing humans, halon is used on airplanes.)

Halon gas is used in concentrations of about 5%, at which level it is not harmful to humans for short periods. It's roughly as poisonous as other short organic molecules. It could be compared to the stuff you smell when using spraycans or working on a motor vehicle: you shouldn't do it all day or intentionally inhale it, but brief infrequent exposure is not particularly harmful. (Presumably your machine room doesn't catch fire every day...)

This is how it works, as I understand it: halon molecules compete with other chemicals in the room to preferentially absorb energy and free radicals from ignition points. This interrupts the chain reaction, so that energy liberated by burning goes into decomposing halon, rather than into setting more stuff alight. For this reason it can work at low concentrations.

The products produced when halon burns are bad for you, but as another poster pointed out they're no worse than other chemicals produced in a machine room fire.

Production of new halon systems has been tightly restricted because of their potential to damage the ozone layer. That says nothing about whether they're harmful for humans. (Indeed, the high UV flux that causes ozone breakdown in combination with CFCs would be pretty bad for you...)

Some links:
Chemistry of Halon

About Halon

Simple messages:

- Read and understand the MSDS (material safety data sheet) for chemicals in your workplace.

- If an uncontrolable fire breaks out, everybody should leave the room in an orderly fashion, close the door behind you, and call the fire service.

The precedent legal case is the Carterfone decision from 1968.

The short version is: AT&T tried to prohibit a third-party device at the customer's premesis from connecting to network, and they lost. Thus opened up the market for telephones made by companies other than Western Electric.

The Cellular industry is probably going to go the same route; they'll fight this, and they'll lose (sooner, ones hopes, rather than later).

I cited an example that would be relevant to the readers of /.; it was not an example but an illustration, an analogy by way of familiarity. Your accusation that I was comparing a journal with /. is unfounded, and shows your bias and subjectiveness.

As a further illustration of the point of the tyranny of the majority or of the orthodoxy, consider the history of Galileo (persecuted by the Catholics, a threat to their control of the masses). In the medical field consider Jenner, Semmelweis, Morton, Pasteur, and Lister - all remarkable people that were trashed by the establishment because they had novel ideas. Their ideas are now part of accepted thought, but at the time they were thrown out of their professions for having ideas contrary to the orthodoxy.

Suppression of counter-ideas is nothing new. And that suppression in current "scientific" journals is well documented. Everything from Scientific American (check out their treatment of Forrest Mims for example) to Science, Nature, and National Geographic.

Sure there are rotten ideas brought forward by creationists; we all have rotten ideas some times, creationists, evolutionists, or agnostics. But the good ones don't get considered, and even when well peer reviewed are rejected sometimes for possibly undermining the orthodox position (see Gentry's book for exhaustive and frankly boring documentation of this).

Er, I've got to respond to a few of the points raised above...

Where did you get this idea? The question of whether or not the external pressure on the capsule is 1ATM or 0ATM is moot, because the whole idea of hatches and airlocks is to keep everything on the inside of the in. In fact, the astronauts would have an EASIER time getting out here on earth because there would be a smaller pressure differential to work against in opening the airlock than there would be enroute to the moon.

The capsule atmosphere after launch was actually much less than sea level (5 psia), so the external pressure would make a significant difference. The point of pressurizing to greater than atmospheric during the test was to simulate the pressure difference between the capsule and outside, not the true internal pressure to be used after launch. In fact, since the capsule was designed to contain internal pressure greater than than outside, it probably wouldn't have been structurally possible to hold a sub-atmospheric pressure inside.

So now that we've got that little bit of science out of the way, the next problem with your "analysis" is that a difference between 1ATM and 16.7PSI does not result in a *HUGE* difference in available O2. For the clueless, 1ATM=14.7 PSI, or a difference of just 2PSI.

Bzzzzt. For the clueless, what is generally considered 1 atm (the stuff we breath) consists of about 79% nitrogen. Compare this with 16.7 psi pure O2, and I think you'll see a difference.

I've got no idea why the original post of this thread is now rated "Troll" because the poster is essentially correct in many details, unlike the previous post. If the pressure in the capsule is a constant "few" psi over the outside, there is in fact a "HUGE" difference in the flammability and available oxygen inside when it is pressurized on the ground versus in space. Things are going to be way more flammable at an absolute pressure of 16.7 psi O2 than at the flight level of 5 psi O2 in the cabin. In fact, in normal air, the oxygen partial pressure is about 0.21*14.7 = 3 psi. Imagine having 5x more oxygen available! Anything not already completely oxidized will want to burn (and fast!), even materials that are essentially fire-proof in air and low O2 pressures.

> hard to imagine a fast-moving cloud of fine dust particles causing such damage

High pressure steam causing damage

Bring back project Pluto! - see also SLAM, powered by the mighty Tory IIC
launching 55 gal drums with nuclear power!
Dr Strangelove, I presume?.
Discussion of project pluto
Sheesh, the word insane comes to mind.

Bring back project Pluto! - see also SLAM, powered by the mighty Tory IIC
launching 55 gal drums with nuclear power!
Dr Strangelove, I presume?.
Discussion of project pluto
Sheesh, the word insane comes to mind.

Bring back project Pluto! - see also SLAM, powered by the mighty Tory IIC
launching 55 gal drums with nuclear power!
Dr Strangelove, I presume?.
Discussion of project pluto
Sheesh, the word insane comes to mind.

Bring back project Pluto! - see also SLAM, powered by the mighty Tory IIC
launching 55 gal drums with nuclear power!
Dr Strangelove, I presume?.
Discussion of project pluto
Sheesh, the word insane comes to mind.

Reminds me of when the Apollo 12 mission to the moon was struck by lightning shortly after liftoff. Here's an article including pictures. Pretty amazing that the spacecraft's electronics survived this and they still managed to go to the moon after rebooting everything. Here's an item from the RISKS digest about one of the reasons why that worked.

do we really need an "open source" enclopedia?

Yes. Definitely so.

An open source encyclopedia has problems, certainly. It might not even qualify for the strict use of the term "encyclopedia", but I'd still hate to lose them.

Here's a couple of "open source data repositories". See what you think:

• Norman Yarvin's hand-selected Usenet Archive
  Hand filtering of old Usenet that one guy thought was "useful". Idiosyncratic, unauthorative, and terribly useful. It's also quite nostalgic for the "good old days" of Usenet; names like John De Armond and Garry Coffman
• Hitchiker's Guide
  What started out as a very pure attempt at an "open source encyclopedia", but now has some serious issues over moderation and editorial control. Now it seems to be de-evolving into a chatroom