First, the solar wind is neutral (it has to be, otherwise the sun would build up a huge charge of the opposite sign and pull the emitted particles right back).
Second, the impact of charged particles wouldn't inherently alter a rock's orbit in a different way from uncharged particles. They'd both push in the direction of flow. The thing that makes the Yarkovsky effect work is that it depends on re-emission of particles (photons, as heat), and the direction of re-emission depends on the axis and rate of rotation.
Storage batteries are not widely available in 48 VDC, so battery backup becomes a lot more expensive (a 12 VDC system can use any old deep-cycle battery, which is what I got to re-power my UPS when its gel cells died).
Linear regulation for low-power, low-cost devices becomes far less efficient; the alternative is to make the cheapest power supply a lot more expensive.
Aside from that there is no strong reason to prefer either voltage for running low-power devices. As for powering the computer off an external PS which also runs outside peripherals, I think that the needs of the computer vary so much between types of units that a one-size-fits-all power brick would cause too many problems with the tradeoff between capacity and expense. The computer is a big enough load to merit its own PS (though it might share the backup battery with the peripheral brick).
I think your point about money spent on social programmes hurting competitiveness is valid. However these programs are worth it despite the cost.
As you are not a US resident, you probably don't appreciate the true nature of these programs. I'll list them for you, with my complaints:
The Shuttle program mainly continues to keep the program's suppliers and contractors in business. The same people could produce far more in the way of truly useful goods and services if they were merely diverted to working on different launch systems, but today's gravy train is guaranteed while any change implies risk to the contractors (the taxpayer would properly see it the other way, but the taxpayers do not have lobbyists working the capitol).
The USA used to have a program of farm set-asides, where farmers were paid to idle some of their acreage and prevent overproduction. This guaranteed farmers a profit on those acres and kept prices from tanking. This program was replaced with one of pure subsidies 20 or so years ago. The results have been predictable: we have rampant overproduction while prices remain too low for many farmers to remain in business, all at taxpayer expense.
Ethanol subsidies mostly go into the pockets of wealthy corporate interests like Archer Daniels Midland. Some of the surplus corn (from the excessive subsidies) is consumed by the ethanol program, but the taxpayer pays more for a gallon-equivalent of motor fuel produced by this method than a British driver paying 75 p per liter. Ethanol production requires roughly a gallon-equivalent of fossil inputs to produce 1.2 gallons-equivalent of output, at a subsidy of $1.90/gallon; if I have that right, the taxpayer is paying $9.50/gallon for the energy actually created by this process. The rest of the energy is merely transformed from other forms, such as coal, gas and petroleum used on the farm.
"Special education" for children who will never be able to function on their own is likely wasted. "Education" for those who are both mentally defective and dying from their conditions is completely wasted.
Spending a million dollars (or a half, or a quarter million) to save a very premature infant, when the parents cannot support such a child's needs and the child will sustain serious brain damage, is wasted. Once these babies are born there is nothing medical science can do to make up for the damage that results. We would save more lives by letting them die naturally and putting the money into prenatal care, schooling and programs to prevent pregnancies among people who won't take prenatal care seriously.
These programs are not worth it; they destroy value, not create it.
I think you may be advocating a specific doctrine on earth development rather than defending scientific research. Scientist are now finding evidence that things can happen very "quickly", and not everything follows the slow, orderly process.
"Quickly", in geologic terms, is thousands of years. The measured rate of the decay of Earth's magnetic field is 0.07% per year. You should have known this before posting.
This causes problems for many people because it opens the possibility that humans might have a significant impact on the environment, or the environment might not be as long term stable as we have assumed.
(Ignoramus, or troll? should I post this? what the fuck...) I am frankly astounded that there are so many tinfoil-hat wearers on Slashdot. While there is ample reason to believe that human activity is changing forest cover, cloud cover, local rainfall and even the global climate, there is zero reason to believe that anything we have done or even anything we could conceive of doing with what we have could affect Earth's magnetic field. And I mean zero: the electric currents and circulatory flows in Earth's core which produce its magnetic field are beyond the reach of anything we can do directly. I defy you to produce even one credible (published and peer-reviewed) reference to the contrary.
I will grant one speculative possibility, and that is that climate change alters the distribution of water (and thus mass) over the earth from polar regions toward the equator, causing Earth's spin to slow and changing the interaction at the boundary between the semi-solid mantle and the liquid core. But if that were a big factor we would see magnetic field reversals coinciding with the ebb and flow of glaciation, and AFAIK that has not been observed in the geologic record. Feel free to correct me if you find evidence to the contrary.
Taking things slightly out of order (I do not suffer fools gladly):
the word 'conductivity' refers to a property of a material in respect to how it behaves in relation to electromagnetic engery, so I don't see this as being completely off the wall.
That's the kind of hand-waving explanation I expect from people who have no understanding of what they're talking about. Scientists and engineers have quantitative understandings of such things, down to the fundamental units they're working with. FYI, conductivity is the inverse of resistivity, and for bulk materials has the units of mhos per meter (for a conductor of uniform area you multiply by square meters of area to get mho-meters, then divide by the length in meters to get mhos).
let me put you straight on some of the mechanics of optical/holographic memory. Firstly, it doesn't employ a rotating mechanism...
My cursory examination of your example shows that it does indeed demand a rotating mechanism, to change the angle of the recording/playback beam relative to the medium.
Your default posting score of 0 appears to have been earned justly.
Lastly, by saying that hard drives do not last long enough to be affected by events that happen in 'geological time' is an assumption. There is nothing to tell us for certain that the Earths' magnetic field will not flip tomorrow or next week, or next year. This is a real possibility within our lifetimes...
The same laws of physics which create the earth's magnetic field (magnetic induction) prevent it from changing rapidly. If you'd bothered to do even the most trivial Google search on the topic (I used ``earth "magnetic field reversal" ' '), you would have found this NASA page. A quote from one of its pointers:
Is the Earth's magnetic field changing?
Indeed it is. It currently has a strength at the Earth's surface of 0.6 Gauss. But long term observations show that it is DECREASING at a rate of about 0.07 percent PER YEAR. This means that in 1500 years from now, it will only be about 35 percent as strong as it is today, and in 4000 years it will have a strength of practically zero.
Needless to say, this rate of field change is no threat whatsoever to magnetic media of any kind. A 7200 RPM hard disc can already see the Earth's 0.7 gauss field reverse itself 120 times per second (assuming it is oriented correctly), and this poses no difficulties whatsoever for storage. The idea that a change requiring 4000 years would be a problem for your HD is simply preposterous. The first search result also debunks any notion of sudden or tragic results.
As for your fear of people with mod points who find comments interesting...
I'm not afraid of them, or you. I fear for the future of this society, because people like you and they actually think you understand these things well enough to claim an opinion on the matter. As even the most trivial of attempts to educate yourself would have given you (or the moderators) authoritative information to the contrary, and as Slashdot users are selected from probably the top 10% of the population, this should worry everyone.
Would this plastic storage would be sensitive to magnetic damage like a traditional hard disk as well.
Why would a material whose properties depend on conductivity be affected by magnetic fields? C'mon, think before posting.
As well as optical storage (which we already use with spinning discs CD/DVD) optical memory will be able to integrate into optical processors
If you can only scan it at the speed of rotating media, you're way too slow for even secondary storage.
Finally, I read that the Earths' magnetic field can 'flip' every 100,000 years and we're about due for another flip soon. This would cause tremendous damage to all magnetically stored data, as well as plenty of electrical equipment, as it is not a quick clean flip, but equivalent to a massive electromagnetic storm right under our feet...
The flip of the poles is on-going, and has been going on for thousands of years. The pole-flip is to EMP (or anything else that might damage magnetic media) as the millimeter/year changes in sea level are to tsunamis.
(And IMHO, anyone who moderated the parent as "interesting" is even more ignorant than the poster. There are at least three of them with mod points in just one day, and that scares me.)
Computers could take a hint from automotive
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Need... More... Power...
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Because most computer peripherals use either 5 VDC or 12 VDC, why not have a small array of 5V and 12V jacks in the back of PCs?
To start with, what happens when you run out of jacks in the computer?
This solution would let you dump a bunch of wall-warts and probably be more energy efficient too.
Or possibly not. If you need something like 8 volts in a peripheral (to run a CD drive's motors, to give just one example) you couldn't get it easily from +5, so the most likely solution is to use a 3-terminal regulator to get it from +12. This throws away 33% of the power as heat. To get really efficient requires switching power supplies (which I think are great, but they are nowhere near as simple and cheap as a 3-terminal regulator).
In practice you'd like a power bus fed by some big central PS that doesn't depend on the computer. This PS would provide for standby power to peripherals, like the ATX standard. Compliant peripherals would take a trickle of power from the bus during "sleep", and wake up (turn on their main power supply, reset and boot) on some electrical command. Some other command, or a sustained period of inactivity, would set them back to the sleep state.
This is pretty much what many cars have today, using the Controller Area Network (CAN) bus. CAN modules "sleep", some with their RAM powered on and all with their comm chips running, on less than a milliamp. The speed is not up to computer specs (0.5 mbit/sec or so), but the techniques could easily be adapted to something like FireWire if the will existed or one manufacturer had the pull to create a de-facto standard. With something like this you could have a "power strip" like a laptop brick, putting out 12-14 VDC for a host of peripherals and maybe the computer as well. You might not get rid of all the wires (though a combined power/data bus could do that too), but you'd certainly get rid of all the wall-warts. It would make backup pretty trivial, too (just hook in a deep-cycle battery). Who wouldn't want that?
As a citizen of the USofA I face facts about the huge wastes of money we endure every day, such as:
The dead-end Space Shuttle program
Farm subsidies
Ethanol subsidies (which intersect somewhat with the above)
Mandated "special education" to the student's needs regardless of cost, while regular classrooms languish and the gifted are conspicuously neglected
Million-dollar healthcare for very premature infants (who will be lucky to ever get past "special ed")
That doesn't include other things which could save piles of money, such as making the people who "develop" rural areas pay the full cost of all the roads, sewers, schools and whatnot that they require while abandoning cities where all those things already exist.
Getting back to space, it no longer surprises me that the price of several Apollo projects has not taken humans beyond LEO in 3 decades nor given us a real space station, while a few tens of millions in SDIO gave us an SSTO technology demonstrator and one aerospace engineer was able to construct a scenario for a full manned mission to Mars for a fraction of the Shuttle budget. It disgusts me, but it is not surprising... it's all money politics, and the future is sold down the river because it has no constituency while the past chows down at the trough. Kind of like the pandering to old people with "free" drugs while the children whose future is going to be largely determined in classrooms over the next 10 years are ignored beyond mandates on top of mandates which all go unfunded.
(the problem with) Steel Buildings
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Pre-Fab Homes?
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There are some issues with steel that anyone ought to be aware of before buying:
Steel is an excellent conductor of heat, and studs and rafters will cause lots of "thermal bridging" between the indoors and out. This requires a substantial amount more insulation to fix than you'd need for conventional construction. (Your contractor wouldn't give a crap about this because they are not going to be paying the heating/cooling bill.)
You can't just let any old contractor do your wiring. Holes through steel studs have sharp edges, and any wiring (and probably plumbing too) going through them has to be protected with special grommets. If you miss this, you could have some very expen$ive mistakes in your house.
I'd also watch for things like reduced room-to-room acoustic isolation, but I have not had an opportunity to check out a steel house first-hand so I can't say if they're better or worse.
If the car won't meet emissions it can't be sold (there are recalls for that all the time).
For the average mechanic, knowing about carburetors or points is a complete waste of time. No car has rolled off a high-volume assembly line with either in years, and even the distributor is going the way of the dodo. If he wants a job he learns about the stuff that comes into the shop every day, not the only-driven-on-Sundays classic that goes past his house a few times a year.
I don't have a problem with cars that are only good for 15-20 years before they become effectively unmaintainable. Back in the 60's they were good for a heck of a lot less than that, and if two decades is the limit imposed by the need to keep the pollution controls and such effective, I'll take that tradeoff.
Maybe the question shouldn't be 'should the software in cars be open source?', maybe it should be 'should cars have software based controls in the first place?' Not just cars, but lots of things.
You can say that, but the problem is that the internal combustion engine is a pretty sloppy device. There are clearances and component tolerances from the mass-air meter and fuel injectors at the intake to the HEGO sensors in the exhaust manifold, and everywhere in between.
No two engines are exactly alike; hell, no two cylinder heads flow exactly the same, and without being able to meter and adjust to the air flow you can't get the mixture right. If you don't have the mixture nearly spot-on (varying between lean and rich, to load the catalyst with oxygen and then burn it off) your pollution controls don't work worth a damn. And if your pollution controls don't work, our system of big cities filled with lots of vehicles suddenly becomes very, very hostile to human health and well-being (again).
Software-based controls are the antidote to manufacturing tolerances and wear. You can't build mechanical or even analog controls with the required complexity and get the necessary reliability. Computers are the patch for getting cars to the shop ("CHECK ENGINE") rather than having them just belch out tens or hundreds of times as much gunk as they ought to. You could perhaps find a way to build one all-mechanical engine that could operate within EPA limits, but it would cost a fortune and you might not be able to depend on it staying that way for even 5000 miles, let alone 50,000.
The auto companies once settled on a protocol system for talking to the car; they called it J-1850 (and there were individual corporate flavors thereof like any "standard" in the industry). This was required by the EPA so that any car could be tested with the same equipment for smog verification. But the EPA didn't require a common service protocol, so unless you can scare up an interface somewhere and a manual for interpreting the codes, you're up a creek without a paddle. Unless you can find an old phone book with names of shops servicing your brand of 10 years ago or so; a mechanic who's still in business might have one of the old testers gathering dust.
And a telephone analogon to dyndns is impossible is it not?;-)
So all the police would have to do to follow your "un-followable" changes of phone is to read the number forwarding information you so courteously furnish them via this dynamic-phone-number service. Somehow I think this defeats the purpose.
If I posted after your concession, my apologies; I didn't look around after I started composing.
However, your assumptions on coal are suspect. It assumes that the total amount of carbon in coal is converted to CO2 during combustion. Is none of it converted to other chemicals? Is there no "soot"?
No, not really. Coal plants burn with enough excess air to get very good combustion. There is some carbon lost that gets incorporated into the ash, but if I understand correctly you're talking about single-digit percentages.
However, you're still clinging to a false impression here:
I meant total pollutant gases.
There you're certainly wrong too. 17 megatons of SO2 doesn't appear to be much, when you consider that the Wabash River plant in Terre Haute recovered about 11,000 tons of pure sulfur per year from a coal-burning plant that only produced about 260 MW net. If we take a rough figure of 500 GW for the coal-fired generation capacity of the USA and scale accordingly, that would be 22 million tons of sulfur per year which would make about 44 million tons of SO2 - close to 3 times the emissions from Pinatubo's 1991 eruption. So no, it would take a LOT of volcanoes to equal human outputs even of SO2.
From your link: "The remainder, in gaseous form, can be collected by cold traps or similar devices." Also, "In contrast, material utilization rates for molecular beam epitaxy (MBE) deposition process are 40 to 70% mol% for Ga and 10 to 20 mol% for As."
I read that as saying that what's not left in the machine is typically brought out in recyclable form; you can distill condensed vapors and re-use them, and molecular beam technology can boost utilization if it matters that much. I can't see that you refuted anything I said.
I can't find the exact quote by I believe it is from Zubrin talking about the latest 18-20% eff Solar cells and how they cost more to manufacture in energy than they will ever produce.
Well, yeah. The bleeding edge is always expensive. Now if you're talking $4/watt amorphous silicon cells, if they cost more energy to produce than they'll make in 20 years each watt of cell would take... hmmm, need an envelope...
1 watt * 6 hours sun/day average *.8 derating factor * 365 days/year * 15 years =
26 kilowatt-hours. That's the energy equivalent of about 2/3 of a gallon of gasoline, or 3.3 gallons of gas if you consider the typical conversion efficiency of small to medium size engines. I find it doubtful that you could spend even a dollar on energy to make a cell that retails for four dollars, plus I've read that the payback time for the best panels these days is only a couple of years. I'll take better data when I can get it, but right now I don't think that the bleeding-edge economics applies to the stuff a consumer would buy.
Of course, not all solar is PV (see this, they updated their site), and wind pays back very quickly in any kind of decent site.
Some of the stories about cheap flexible solar arrays being made soon are promising but until there are demonstrateable enviromental and economic advantages over nuclear power I am reluctant to consider them a panacea and more of a hinderance to the energy crisis.
Solar PV currently costs about $.25/KWH, but peak time-of-use electric rates in some areas are $.35/KWH and up. Solar PV is actually cheaper than the grid there while it's producing, or will be unless and until something flattens the demand curve. Solar PV has been cheaper than paying to extend electric service for well over a decade. Then there are breakthrough technologies such as have been discussed on Slashdot in the last couple of months, any one of which could throw a real curveball.
I've got nothing against nuclear, but its improvements are going to be incremental. Wind isn't bad, but barring tricks like gyromills it is going to move incrementally too. PV, photochemical, and other things are still improving on an exponential curve; those are the ones to watch.
I want to take issue with this and similar statements:
Pinatubo expelled more CO2 into the atmosphere than the entire history of industrialized civilization.
You could not be more wrong. Pinatubo emitted on the order of
42 Mt of CO2 and 17 Mt of SO2. In contrast, in the year 1999 the state of Ohio consumed about 57.5 million short tons of coal. If we assume 88% carbon, that is 50.6 million tons of carbon which would burn to (50.6/12*44) = 185 million tons of CO2, or about 4.5 times as much as Pinatubo emitted. And Ohio does this every year, and it is one state in the United States, which is only one of many coal-consuming nations...
Pinatubo was spectacular, but its CO2 contribution wasn't even a blip on the scale. Worse, even a trivial amount of research would have dispelled your misconceptions. Don't you know how, or don't you care?
Do you know how nasty photovaliac cells are to manufacture?
Let's see: use CVD to turn silane into elemental SI on glass, dope and apply contacts. Silane and arsene are nasty stuff, but they tend not to get outside the plant and you only need traces of arsene while silane tends to self-ignite and turn into SiO2. So I'd guess, not very nasty at all.
I would presume it would cost more in resources to create the solar cells than you would ever get out of them in energy production
I presume you know what they say about presumptuous people.... whoops, now I did it!
I don't think that the process of mountain-top removal mining is particularly friendly to the environment, no matter how cleanly you can burn the stuff once it's been shipped elsewhere. If you are going to promote more coal consumption, you've got to have a recipe for reducing its impacts from one end of the chain to the other or you're vulnerable to criticism and even injunctions.
Because environmentalists want to change a lot more than power generation. The big sources of greenhouse gasses aren't power plants so much as factories, the ones that make the things than we use to maintain our standard of living.
I've been studying this issue a bit, and your claim appears bogus. For coal, for example, something like 90% is consumed by electric power plants in my state (which still has a fair amount of industry). I have not studied the consumption of oil and natural gas by factories (I'm currently plowing through data particular to the electric industry) so I can't say if that conclusion holds across the board, but your claim looks suspicious in the light of what I know.
But even ignoring that, renewable energy sources have their own problems environmental associated with them. Going all solar or all wind, for example, means clearing a lot of land that might otherwise be natural wilderness.
Obviously you have not looked at the figures. The top 11 states for windpower have over a terawatt of potential, and the energy is mostly available in plains areas rather than the forested or mountainous areas we consider wilderness. Solar could do an amazing amount of work with just the light that currently falls on rooftops (the land isn't just converted already, it's under buildings). When you consider how much energy use can be eliminated with proper selection of appliances and construction practices, the houses in the Solar Decathlon competition last year "would use only one-third of the energy of a basic code-compliant house the same size, and about half the energy of an Energy Star complaint house" even without their solar collectors (Home Power magazine, issue 96, page 62). If we forced the production of materials such as SIPs up by increasing insulation requirements in building codes, the economies of scale would reduce costs even more and make a purely economic argument attractive even without the environmental issues.
You don't want us to be prejudiced against the views of environmentalists because of who they are ("tree-hugging hippies looking for a cause"), but you seem to be prejudiced against the views of non-environmentalists because of who they are ("money-grubbing fat cats looking for a quick buck").
I'm prejudiced against the watermelons (green on the outside, red on the inside) for whom the environment is an excuse to impose a social(ist) agenda. But if that invalidates the data which supports environmentalism, then a few fanatics invalidate Christianity. You wouldn't accept such reasoning in other matters, so don't put it forward to support your agenda.
Now, I'm not a climate researcher. But I do know that there's a lot of spectacular evidence supporting the claim that global warming exists and is accelerating, and a pretty firm body of theory rooted in physics to show how it occurs. I don't see how you can dismiss things like the retreat of glaciers around much of the globe (to sizes unprecedented in history or the recent archaeological record) and claim that nothing is going on.
No, they have an agenda. They have a belief that they feel strongly about, and they want others to either believe it too, or at least be held to the constraints that those beliefs create.
That's like claiming that people who oppose promiscuity because it spreads AIDS are puritanical, or people who promote condoms to prevent AIDS are libertines because condoms make promiscuity relatively safe. Both arguments are fallacious.
The problem with your statement is that you're ignoring the fact that there is a gray area.
The problem with yours is that there are other costs to fossil fuels. Coal, for example, puts enough mercury into the environment that it's unsafe for people to eat fish steadily in my state. Becoming more efficient can often be done at a negative cost, completely aside from pollution or climate considerations. Then there is the net present value of the (uncertain and climbing) future cost of many fuels, including natural gas. If there is a gray area, it starts at a much lower level of energy consumption than we have today; the purely economic arguments for cutting back a good ways are solid without even thinking about climate change.
Funny you say that when the article mentions NOTHING about any business being involved in the contradicting studies.
University of Guelph. One of Canada's biggest exports is energy, mostly from the province of Alberta. The value of several large corporations could evaporate if e.g. the tar sands were regarded as too polluting to exploit. Corporations have lobbyists, their employees vote their personal interests. You do the math.
I tried to debunk that idea by showing on incident where the rapid depressurization caused a catastrophic failure of an aircraft.
Yes, rapid depressurization. Such as caused by the loss of the aft cargo door on a Lockheed L1011 a while ago, which caused enough delta-P between the cargo bay and upper cabin to collapse the floor, sever the controls and bring down the aircraft.
A few bullet holes are several orders of magnitude smaller than than a cargo door.
I also didn't mention things like bullets damaging vital systems like hydraulics or electrical.
Airliners have multiple independent electrical systems. Ditto hydraulic systems. And if you think that a frangible bullet is going to have enough oomph to take out a stainless hydraulic line after taking on a sheet-metal floor, you probably have never shot anything with one. I have. They do a pretty good job of dumping energy fast and not penetrating much.
Instead of arming passengers (or even pilots), how about making it impossible to enter the cabin with locked, bullet proof doors so that hijackers can't commadeer a plane in the first place.
You mean, the way El Al did long before 9/11?
There are lots of other options that can be done that would reduce or eliminate the threat of a 9/11 type hijacking before resorting to letting armed civilians on a plane.
Oh, of course. But relying on any one measure to guarantee that it can't happen again is just asking for some clever terrorist to find a way around it and make fools of us again. Broad but thin defenses fail "brittle"; what you want is a "defense in depth", where bypassing one layer comes up against deeper layers.
As for Aloha Airlines flight 243, that incident is the exception, rather than the rule. Had it not been for the skill of the pilot, that plane would most certainly have gone down.
sigh Again, you missed the point. A nearly-instantaneous decompression did not bring the aircraft down. The air leaks from a few bullet holes, or even a lost window, would not pose any threat to the airworthiness of an airliner, in direct contradiction to your thesis.
I never claimed to be an expert, I was only responding to the parent post with direct contradictions of his claims.
A pity that your ideology combines with a few factoids to let you reach a false conclusion with perfect confidence.
If what you say is true, I guess it's not good to have any kind of gun on an aircraft and depressurization cause by gunfire is a very real danger...
To reach your conclusion, you had to completely ignore the original poster who said "Aircraft are presurized by bleeding compressed air from the engines into the cabin (after cooling it first). And how does the air remain fresh ?? BY BLOWING OUT OF THE HUGE HOLES AT THE TAIL-END OF THE AIRCRAFT." (He's not exactly correct; those holes aren't "huge" by conventional meanings of the word. But the exhaust valves are quite large on big aircraft, and can vent air more than fast enough to be a problem if they stick open.)
In another response, you said:
The danger in a bullet penetrating the skin of the aircraft is not that passengers are being sucked out, is that rapid depreasurization at high altitude can cause structural failure of the aircraft, total incapacitation of the passengers AND crew (including death).
You make two claims:
That a bullet can depressurize the aircraft, and
Depressurization can cause airframe failure.
Both claims are false. The incident of Aloha Airlines flight 243 demonstrates conclusively that the second is false. To prove that the first is false, all you have to know is that the maximum speed of a confined stream of gas is the speed of sound in the gas. Given that the speed of sound in air at room temperature is about 1100 feet per second and that a bullet hole would be much less than one square inch in area, it is elementary to calculate that the rate of air loss would be several seconds per cubic foot. Such a trivial rate of loss would be made up by the pressurization systems without noticing.
As for what happened to Payne Stewart, you might consider that he was flying on a Learjet (vastly smaller cabin volume) and was also probably flying at a considerably higher altitude. The fact that the cabin pressure regulator valves had been serviced shortly before the crash ought to be a clue about how important they are. A half-inch hole wouldn't be a problem even in such a small jet aircraft. For a turbocharged piston plane like a Piper Malibu or a Cessna P210, it might be another matter, but not for a Lear.
Last, the unarmed passengers on the plane which went down in Pennsylvania were sufficient to foil the hijackers' plans; had the hijackers not been intent on dying, the passengers would have retaken the plane. If you consider the post-9/11 calculus of resistance, even if the hijackers (immigrants, several of them on watch lists) had been armed it would have been far more likely that they would have lost an armed confrontation against armed passengers. The best weapon they could get today is surprise, and once they try to seize hostages or storm the cabin the element of surprise is gone.
Mind you, restricting access to radical sites into any subject to minors is the main focus of the software we are talking about here.
How did you ever get the idea that the NRA was radical about anything? They are stick-in-the-mud, don't-want-change conservatives. Any confusion between their "leave me alone" agenda and the goals of the real radicals on the right (like the theocrats, or the police-statists such as John Ashcroft and our wonderful homeland security czar) is purely due to your own lack of education on the topic.
So far as I can tell, the NRA is correct. All of the various anti-gun acts passed in the 1960's and later have failed to produce the benefits claimed for them; crime rates exploded after the Gun Control Act of 1968, for example. It was definitely time to stop the knee-jerk reactions and look around for other solutions to the problem... oh, 20 years ago.
Insanity, n.: Doing the same thing and expecting a different result.
Fanaticism, n.: Redoubling one's efforts after losing sight of one's goal.
firing a gun in an aircraft cabin will likely lead to an imminent crash.
This has been disproven dozens of times in government-sponsored tests. Bullets will neither cause abrupt decompression nor can they cause catastrophic failure of the airframe or even a side window (they are made of Lexan and will not shatter). You can calculate the maximum rate of air loss, because the speed of a gas escaping through a narrowing passage cannot exceed the speed of sound in the gas. For a hole of 10 mm or so, it just isn't much.
The noise of air whistling out might be a problem, but the people who just heard muzzle blast inside an enclosed cabin probably wouldn't be able to hear that in time for it to become a big concern either. If it bugs anyone, you can always stuff the hole with a corner of a pillow.
Once some describes an idea in open literature, nobody else can even attempt to patent it unless they can prove priority. The inventor has one year to file, in the United States. Once that year has elapsed, the idea cannot be patented.
So there's your patent-free idea database: publications of any sort. This ought to be obvious, because "obvious" is one of the synonyms of "patent"...
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Second, the impact of charged particles wouldn't inherently alter a rock's orbit in a different way from uncharged particles. They'd both push in the direction of flow. The thing that makes the Yarkovsky effect work is that it depends on re-emission of particles (photons, as heat), and the direction of re-emission depends on the axis and rate of rotation.
- Storage batteries are not widely available in 48 VDC, so battery backup becomes a lot more expensive (a 12 VDC system can use any old deep-cycle battery, which is what I got to re-power my UPS when its gel cells died).
- Linear regulation for low-power, low-cost devices becomes far less efficient; the alternative is to make the cheapest power supply a lot more expensive.
Aside from that there is no strong reason to prefer either voltage for running low-power devices. As for powering the computer off an external PS which also runs outside peripherals, I think that the needs of the computer vary so much between types of units that a one-size-fits-all power brick would cause too many problems with the tradeoff between capacity and expense. The computer is a big enough load to merit its own PS (though it might share the backup battery with the peripheral brick).- The Shuttle program mainly continues to keep the program's suppliers and contractors in business. The same people could produce far more in the way of truly useful goods and services if they were merely diverted to working on different launch systems, but today's gravy train is guaranteed while any change implies risk to the contractors (the taxpayer would properly see it the other way, but the taxpayers do not have lobbyists working the capitol).
- The USA used to have a program of farm set-asides, where farmers were paid to idle some of their acreage and prevent overproduction. This guaranteed farmers a profit on those acres and kept prices from tanking. This program was replaced with one of pure subsidies 20 or so years ago. The results have been predictable: we have rampant overproduction while prices remain too low for many farmers to remain in business, all at taxpayer expense.
- Ethanol subsidies mostly go into the pockets of wealthy corporate interests like Archer Daniels Midland. Some of the surplus corn (from the excessive subsidies) is consumed by the ethanol program, but the taxpayer pays more for a gallon-equivalent of motor fuel produced by this method than a British driver paying 75 p per liter. Ethanol production requires roughly a gallon-equivalent of fossil inputs to produce 1.2 gallons-equivalent of output, at a subsidy of $1.90/gallon; if I have that right, the taxpayer is paying $9.50/gallon for the energy actually created by this process. The rest of the energy is merely transformed from other forms, such as coal, gas and petroleum used on the farm.
- "Special education" for children who will never be able to function on their own is likely wasted. "Education" for those who are both mentally defective and dying from their conditions is completely wasted.
- Spending a million dollars (or a half, or a quarter million) to save a very premature infant, when the parents cannot support such a child's needs and the child will sustain serious brain damage, is wasted. Once these babies are born there is nothing medical science can do to make up for the damage that results. We would save more lives by letting them die naturally and putting the money into prenatal care, schooling and programs to prevent pregnancies among people who won't take prenatal care seriously.
These programs are not worth it; they destroy value, not create it.I will grant one speculative possibility, and that is that climate change alters the distribution of water (and thus mass) over the earth from polar regions toward the equator, causing Earth's spin to slow and changing the interaction at the boundary between the semi-solid mantle and the liquid core. But if that were a big factor we would see magnetic field reversals coinciding with the ebb and flow of glaciation, and AFAIK that has not been observed in the geologic record. Feel free to correct me if you find evidence to the contrary.
Your default posting score of 0 appears to have been earned justly.
The same laws of physics which create the earth's magnetic field (magnetic induction) prevent it from changing rapidly. If you'd bothered to do even the most trivial Google search on the topic (I used ``earth "magnetic field reversal" ' '), you would have found this NASA page. A quote from one of its pointers: Needless to say, this rate of field change is no threat whatsoever to magnetic media of any kind. A 7200 RPM hard disc can already see the Earth's 0.7 gauss field reverse itself 120 times per second (assuming it is oriented correctly), and this poses no difficulties whatsoever for storage. The idea that a change requiring 4000 years would be a problem for your HD is simply preposterous. The first search result also debunks any notion of sudden or tragic results. I'm not afraid of them, or you. I fear for the future of this society, because people like you and they actually think you understand these things well enough to claim an opinion on the matter. As even the most trivial of attempts to educate yourself would have given you (or the moderators) authoritative information to the contrary, and as Slashdot users are selected from probably the top 10% of the population, this should worry everyone.(And IMHO, anyone who moderated the parent as "interesting" is even more ignorant than the poster. There are at least three of them with mod points in just one day, and that scares me.)
In practice you'd like a power bus fed by some big central PS that doesn't depend on the computer. This PS would provide for standby power to peripherals, like the ATX standard. Compliant peripherals would take a trickle of power from the bus during "sleep", and wake up (turn on their main power supply, reset and boot) on some electrical command. Some other command, or a sustained period of inactivity, would set them back to the sleep state.
This is pretty much what many cars have today, using the Controller Area Network (CAN) bus. CAN modules "sleep", some with their RAM powered on and all with their comm chips running, on less than a milliamp. The speed is not up to computer specs (0.5 mbit/sec or so), but the techniques could easily be adapted to something like FireWire if the will existed or one manufacturer had the pull to create a de-facto standard. With something like this you could have a "power strip" like a laptop brick, putting out 12-14 VDC for a host of peripherals and maybe the computer as well. You might not get rid of all the wires (though a combined power/data bus could do that too), but you'd certainly get rid of all the wall-warts. It would make backup pretty trivial, too (just hook in a deep-cycle battery). Who wouldn't want that?
As a citizen of the USofA I face facts about the huge wastes of money we endure every day, such as:
- The dead-end Space Shuttle program
- Farm subsidies
- Ethanol subsidies (which intersect somewhat with the above)
- Mandated "special education" to the student's needs regardless of cost, while regular classrooms languish and the gifted are conspicuously neglected
- Million-dollar healthcare for very premature infants (who will be lucky to ever get past "special ed")
That doesn't include other things which could save piles of money, such as making the people who "develop" rural areas pay the full cost of all the roads, sewers, schools and whatnot that they require while abandoning cities where all those things already exist.Getting back to space, it no longer surprises me that the price of several Apollo projects has not taken humans beyond LEO in 3 decades nor given us a real space station, while a few tens of millions in SDIO gave us an SSTO technology demonstrator and one aerospace engineer was able to construct a scenario for a full manned mission to Mars for a fraction of the Shuttle budget. It disgusts me, but it is not surprising... it's all money politics, and the future is sold down the river because it has no constituency while the past chows down at the trough. Kind of like the pandering to old people with "free" drugs while the children whose future is going to be largely determined in classrooms over the next 10 years are ignored beyond mandates on top of mandates which all go unfunded.
- Steel is an excellent conductor of heat, and studs and rafters will cause lots of "thermal bridging" between the indoors and out. This requires a substantial amount more insulation to fix than you'd need for conventional construction. (Your contractor wouldn't give a crap about this because they are not going to be paying the heating/cooling bill.)
- You can't just let any old contractor do your wiring. Holes through steel studs have sharp edges, and any wiring (and probably plumbing too) going through them has to be protected with special grommets. If you miss this, you could have some very expen$ive mistakes in your house.
I'd also watch for things like reduced room-to-room acoustic isolation, but I have not had an opportunity to check out a steel house first-hand so I can't say if they're better or worse.For the average mechanic, knowing about carburetors or points is a complete waste of time. No car has rolled off a high-volume assembly line with either in years, and even the distributor is going the way of the dodo. If he wants a job he learns about the stuff that comes into the shop every day, not the only-driven-on-Sundays classic that goes past his house a few times a year.
I don't have a problem with cars that are only good for 15-20 years before they become effectively unmaintainable. Back in the 60's they were good for a heck of a lot less than that, and if two decades is the limit imposed by the need to keep the pollution controls and such effective, I'll take that tradeoff.
No two engines are exactly alike; hell, no two cylinder heads flow exactly the same, and without being able to meter and adjust to the air flow you can't get the mixture right. If you don't have the mixture nearly spot-on (varying between lean and rich, to load the catalyst with oxygen and then burn it off) your pollution controls don't work worth a damn. And if your pollution controls don't work, our system of big cities filled with lots of vehicles suddenly becomes very, very hostile to human health and well-being (again).
Software-based controls are the antidote to manufacturing tolerances and wear. You can't build mechanical or even analog controls with the required complexity and get the necessary reliability. Computers are the patch for getting cars to the shop ("CHECK ENGINE") rather than having them just belch out tens or hundreds of times as much gunk as they ought to. You could perhaps find a way to build one all-mechanical engine that could operate within EPA limits, but it would cost a fortune and you might not be able to depend on it staying that way for even 5000 miles, let alone 50,000.
The auto companies once settled on a protocol system for talking to the car; they called it J-1850 (and there were individual corporate flavors thereof like any "standard" in the industry). This was required by the EPA so that any car could be tested with the same equipment for smog verification. But the EPA didn't require a common service protocol, so unless you can scare up an interface somewhere and a manual for interpreting the codes, you're up a creek without a paddle. Unless you can find an old phone book with names of shops servicing your brand of 10 years ago or so; a mechanic who's still in business might have one of the old testers gathering dust.
However, you're still clinging to a false impression here:
There you're certainly wrong too. 17 megatons of SO2 doesn't appear to be much, when you consider that the Wabash River plant in Terre Haute recovered about 11,000 tons of pure sulfur per year from a coal-burning plant that only produced about 260 MW net. If we take a rough figure of 500 GW for the coal-fired generation capacity of the USA and scale accordingly, that would be 22 million tons of sulfur per year which would make about 44 million tons of SO2 - close to 3 times the emissions from Pinatubo's 1991 eruption. So no, it would take a LOT of volcanoes to equal human outputs even of SO2.I read that as saying that what's not left in the machine is typically brought out in recyclable form; you can distill condensed vapors and re-use them, and molecular beam technology can boost utilization if it matters that much. I can't see that you refuted anything I said.
Well, yeah. The bleeding edge is always expensive. Now if you're talking $4/watt amorphous silicon cells, if they cost more energy to produce than they'll make in 20 years each watt of cell would take... hmmm, need an envelope...1 watt * 6 hours sun/day average * .8 derating factor * 365 days/year * 15 years =
26 kilowatt-hours. That's the energy equivalent of about 2/3 of a gallon of gasoline, or 3.3 gallons of gas if you consider the typical conversion efficiency of small to medium size engines. I find it doubtful that you could spend even a dollar on energy to make a cell that retails for four dollars, plus I've read that the payback time for the best panels these days is only a couple of years. I'll take better data when I can get it, but right now I don't think that the bleeding-edge economics applies to the stuff a consumer would buy.
Of course, not all solar is PV (see this, they updated their site), and wind pays back very quickly in any kind of decent site.
Solar PV currently costs about $.25/KWH, but peak time-of-use electric rates in some areas are $.35/KWH and up. Solar PV is actually cheaper than the grid there while it's producing, or will be unless and until something flattens the demand curve. Solar PV has been cheaper than paying to extend electric service for well over a decade. Then there are breakthrough technologies such as have been discussed on Slashdot in the last couple of months, any one of which could throw a real curveball.I've got nothing against nuclear, but its improvements are going to be incremental. Wind isn't bad, but barring tricks like gyromills it is going to move incrementally too. PV, photochemical, and other things are still improving on an exponential curve; those are the ones to watch.
Pinatubo was spectacular, but its CO2 contribution wasn't even a blip on the scale. Worse, even a trivial amount of research would have dispelled your misconceptions. Don't you know how, or don't you care?
I don't think that the process of mountain-top removal mining is particularly friendly to the environment, no matter how cleanly you can burn the stuff once it's been shipped elsewhere. If you are going to promote more coal consumption, you've got to have a recipe for reducing its impacts from one end of the chain to the other or you're vulnerable to criticism and even injunctions.
A few bullet holes are several orders of magnitude smaller than than a cargo door.
Airliners have multiple independent electrical systems. Ditto hydraulic systems. And if you think that a frangible bullet is going to have enough oomph to take out a stainless hydraulic line after taking on a sheet-metal floor, you probably have never shot anything with one. I have. They do a pretty good job of dumping energy fast and not penetrating much. You mean, the way El Al did long before 9/11? Oh, of course. But relying on any one measure to guarantee that it can't happen again is just asking for some clever terrorist to find a way around it and make fools of us again. Broad but thin defenses fail "brittle"; what you want is a "defense in depth", where bypassing one layer comes up against deeper layers. sigh Again, you missed the point. A nearly-instantaneous decompression did not bring the aircraft down. The air leaks from a few bullet holes, or even a lost window, would not pose any threat to the airworthiness of an airliner, in direct contradiction to your thesis.In another response, you said:
You make two claims:- That a bullet can depressurize the aircraft, and
- Depressurization can cause airframe failure.
Both claims are false. The incident of Aloha Airlines flight 243 demonstrates conclusively that the second is false. To prove that the first is false, all you have to know is that the maximum speed of a confined stream of gas is the speed of sound in the gas. Given that the speed of sound in air at room temperature is about 1100 feet per second and that a bullet hole would be much less than one square inch in area, it is elementary to calculate that the rate of air loss would be several seconds per cubic foot. Such a trivial rate of loss would be made up by the pressurization systems without noticing.As for what happened to Payne Stewart, you might consider that he was flying on a Learjet (vastly smaller cabin volume) and was also probably flying at a considerably higher altitude. The fact that the cabin pressure regulator valves had been serviced shortly before the crash ought to be a clue about how important they are. A half-inch hole wouldn't be a problem even in such a small jet aircraft. For a turbocharged piston plane like a Piper Malibu or a Cessna P210, it might be another matter, but not for a Lear.
Last, the unarmed passengers on the plane which went down in Pennsylvania were sufficient to foil the hijackers' plans; had the hijackers not been intent on dying, the passengers would have retaken the plane. If you consider the post-9/11 calculus of resistance, even if the hijackers (immigrants, several of them on watch lists) had been armed it would have been far more likely that they would have lost an armed confrontation against armed passengers. The best weapon they could get today is surprise, and once they try to seize hostages or storm the cabin the element of surprise is gone.
So far as I can tell, the NRA is correct. All of the various anti-gun acts passed in the 1960's and later have failed to produce the benefits claimed for them; crime rates exploded after the Gun Control Act of 1968, for example. It was definitely time to stop the knee-jerk reactions and look around for other solutions to the problem... oh, 20 years ago.
Insanity, n.: Doing the same thing and expecting a different result.
Fanaticism, n.: Redoubling one's efforts after losing sight of one's goal.
After a while you can make the blocks mandatory, and nobody will notice.
You are familiar with the parable of the "camel's nose in the tent", aren't you?
The noise of air whistling out might be a problem, but the people who just heard muzzle blast inside an enclosed cabin probably wouldn't be able to hear that in time for it to become a big concern either. If it bugs anyone, you can always stuff the hole with a corner of a pillow.
So there's your patent-free idea database: publications of any sort. This ought to be obvious, because "obvious" is one of the synonyms of "patent"...