Slashdot Mirror

Better warning systems... Wanna fill out forms telling the government exactly when you plan on turning on your lights?

The power company doesn't get an early warning for how much power people are going to use. They can guess based on weather conditions and history, but that's not accurate enough a number for them to work with.

Remember back to physics class... (or read this on How Stuff Works if you can't...). Voltage equals current times resistance. And anything that you plug in to use power is a resistor. What this means in simple terms is that whenever you turn on anything, you've changed the resistance value on your local power network, so either you've just changed the voltage on the power network, or some power generator somewhere is going to have to step up to the plate and provide more current.

If you've ever read APC marketing material, you know that you want your computer, and for that matter everything else you plug in, to get a nice steady dose of 120 Volt power. There's a little room for tolerance, but not much.

So, whenever a city's power draw changes, the electicial system's gotta react pretty quickly. Too little voltage is a clear problem, it's a brownout. Too much voltage is also a problem, it's a power surge. The large power grids come into play as a way for a network that has too much power and a network that has too little to solve each others problems by joining together and letting physics do its thing.

So, when something goes horribly wrong, it takes nine seconds for a ordinary day to become a bad one. Nobody had any warning because the power grid has to react instantly to unexpected situations, and usually does just fine. It was the one time it didn't react properly that we all noticed.

That should be here, methinks :-)

Take a look h ere</a>. Meanwhile let me read it and get back to you guys.

for all of us who failed electronics/electrical engineering: blackouts for dummys

What I really want to know is what kind of royalties do game designers get from the casino? Do the basically lease the machine? Do the designers get a cut of the proceeds? Considering a good run of machines is about 500 units, they've got to be doing something other than selling them to make their money.

In case people are wondering how the power grid works, here is an article on howstuffworks.com on how
The power grid works

Interesting. All of the research I've seen on creatine indicates that it increases anaerobic performance (weightlifting and sprinting). This is because creatine is used via the phosphagen system to provide energy for 10 seconds.

Since football (soccer) matches last 90 minutes and require nearly constant motion, I'd characterize them as an aerobic activity. And endurance is something that creatine doesn't help. So these soccer players probably are taking creatine and it would certainly help them train their speed and strength in practice, but I highly doubt it helps them run hard the whole match.

Heh. I bought my fiance, now wife, a moissanite ring partly because of cost and partly because I really didn't want anything to do with giving money to DeBeers. Anita was fine with it, partly because moissanite has a science fiction connection.

Society, by expressing its will via a democratic government, has the right to determine how property -- intellectual and physical -- is used, but society does not have the right to assume or transfer ownership of an individual's property.

No? Tell that to all the people who were evicted by the government (landlords and tenants alike) when the WTC was built. That's just one example.

Skip down to the part about eminent domain if you must.

According to this, a computer draws less than half the power of a refrigerator.

I think their numbers are a little high, though. By their calculations, I should be paying $30/month just for the computer (which is on 24/7), yet I'm paying about $30/month for everything.

What a shame. The poor write-cycle life seems like a solveable problem though. Isn't the technology magnetic, just like a HD?

Maybe I'll just need to get a spool of copper wire, some ferrite, a needle, and enough free time to fab myself some core. :)

No, compact flash is just a cheaper form of EEPROM. It stores bits based on the electric charge on a 'floating' gate, one that is completely enclosed by glass -- no connecting wires.

The methods used to get the charge on or off the floating gate are fairly drastic: Fowler-Nordheim tunneling, hot carrier transfer, etc. So, there is a certain amount of wear, tear, and electrons embedded in the glass to mess things up. This limits the number of write cycles on any one cell. As cells die, if your file system can work around the bad bits, you might be able to manage for a while. Load leveling HW or filesystems help too.

See http://www.howstuffworks.com/flash-memory.htm for details

Check out How Stuff Works

Discover Magazine just did a story on something like this. Unfortunately the full story is only available in dead tree format. If you wait until next month the older article will be available. You can probably check it out at your Dentist's office like I did if you feel like getting a filling.

EnergyInovations is working on a small version. From the Discover article it discusses how they refined the stirling engine with the best tradeoffs of manufacturing costs to effiency. IIRC they are also making this small enough to make it fit on a roof top.

Geek fact of the day: A stirling engine is an external combustion engine that runs off the pressure created when one side of its engine gets very hot while the other side stays cool. The greater the temperature difference, the greater the pressure, the greater the energy generated.

"Has it been used elsewhere in sci-fi?"

Endlessly, but then we do have a process called StereoLithography which is routinely used to create 3D models from plans.

Slow news day on Slashdot, obviously.

How it apparently works

Of course, both of these are non-magnetic. And holographic memory is still research-only, as far as I know.

I wonder, will magnetic storage (in any number of dimensions) ever get eclipsed by non-magnetic ones like these?

you mean like my
Entropy Accelerators?

Always learning again.
What were we talking about?

The sound of projectile reaching the speed of sound is noiseless?

Yes. The projectile doesn't produce any sound, hence no sound waves can accumulate. (Howstuffworks article)

If you attach a sound buffering device, (silencer) the thing would require much more energy to reach the same muzzle velocity.

A silencer works by decreasing the pressure caused by the hot gas resulting from firing normal ammunition. It's completely useless on magnet-fired weapons, which produce practically no heat, and hence very little pressure. (Howstuffworks again)

The sound of projectile reaching the speed of sound is noiseless?

Yes. The projectile doesn't produce any sound, hence no sound waves can accumulate. (Howstuffworks article)

If you attach a sound buffering device, (silencer) the thing would require much more energy to reach the same muzzle velocity.

A silencer works by decreasing the pressure caused by the hot gas resulting from firing normal ammunition. It's completely useless on magnet-fired weapons, which produce practically no heat, and hence very little pressure. (Howstuffworks again)

mention something covered in a howstuffworks article and sudenly every geek is an expert on gun silencers

Ostensibly the idea is that it has the same effect as nitrous oxide injection; You squirt N2O in there and it breaks up and you get more available oxygen. However I don't see how it could make anything more efficient; The best it should be able to do is improve your emissions.

See how Nitrous Oxide works in engines. You're not quite right. By introducing more oxygen, you're able to burn more fuel, which means more power. It's not about efficiency, because you're not saving fuel or reducing emissions. It's about power. It's the same principle on which a turbocharger or supercharger operates, except those work by introducing more air (and thus oxygen), rather than NO2. As well, since NO2 helps to cool the intake air, it's denser, which means you can get in even more oxygen (same principle as an intercooler on a turbo/supercharger, or a cold air intake on a NA engine).

I may be wrong, but don't you need a small nuclear device to create an EMP.

Because when these dogfight it looks cool. When these dogfight, it looks like squid fucking.

as much as /. is not a good place for medical advice: howstuffworks is pretty good.

If they really new how stuff works they wouldn't be sticking that mouse in their head, owch don't they know how bad a mouse can be for their brain, :-), repeat after me: I will not be putting the mouse inside my cranium.

There are probably lots of articles on the subject that can be bought up with a quick search, but my favourite broad explanation site has their definition here.

Oh yea P.S., US power mains don't run at 120v, the power within your house does. The voltage within your house has been stepped down numerous times since it left a power main. Power mains run in the tens (and hundreds?) of thousands of volts range. There's a lot of cool information on electricity at www.howstuffworks.com, I recommend reading it to all.

Augh. Another learning moment brought to me by Slashdot and HowStuffWorks.com.

BUT, it does say 'It is possible to measure radiation pressure [...]. To make it work you have to use a much better vacuum, [space works] suspend the vanes from fine fibers and coat the vanes with an inert glass to prevent out-gassing. When you succeed the vanes are deflected [by photons, against the white] as predicted by Maxwell. The experiment is very difficult but was first done successfully in 1901 by Pyotr Lebedev and also by Eenest Nichols and Gordon Hull.'

So my point remains, even if my explanation of the radiometer was faulty. You can generate force against white with photons in a vacuum.

A common question.

A good primer: How DNA Evidence Works

Check out the how to pick locks page at the how stuff works website

I think we're missing the point here, it's not the ink that's expensive it's the fact that the print mechanisms are now built into the cartridge, at least in the case of an ink jet printer. So each time you buy a cartridge you are also buying a print head. The ink itself must be a small amount of the price.

HowStuffWorks explains more.

The real scandal here is that the heads can last far longer than one batch of ink. Refilling should be properly endorsed and encoraged by the printer manufacturers, and practices like these should be stopped.

Of course what should actually happen is that people get out of the habbit of printing unless it is absolutely necessary. Most printed pages in the companies I've worked in end up in the bin fairly quickly anyway. What ever happened to the paperless office?

http://computer.howstuffworks.com//power-supply.ht m

It explains how a power supply works much better than I did. This is the result of my own research since my memories were foggy when I attempted to describe it to you. You may also want to refer to this website for additional questions you may ever want answered. It has a plethora of information on just about anything. Be cautious visiting, once you enter it may be hard to pull yourself back out.

Enjoy!

Perhaps it's been said before but one shouldn't confuse voltage, amps, ohms, and watts for meaning the same thing. A explanation of what each means and how they are related is described at http://www.howstuffworks.com/question501.htm

If your interested I would highly recommend reading up on the ATX form factor. You may want to google for "ATX" "POST" "Power Good" "Pin Out" etc.

So to answer your question; No, power supplies of a specific form factor do not run different voltages (unless they are faulty and at which point the motherboard would refuse power from the offending supply).

Now, different power supplies do have varying amounts of Watts produced. Perhaps this what you were initially asking. To answer in a general manner (stretching my memory again), the higher the watts a power supply can produce, the more devices within the computer it can power. If you have a 400W power supply, and all your devices used 280W, your power supply would provide 280W of power. Think of the watts of a power supply as a maximum capability. A good analogy would be "A Ferrari *can* travel at 200 mph, but that does not mean it is *always* traveling at 200 mph". Same thing with power supplies (for the sake of simplicity and my own limited "expertise").

Hope that helps. When in doubt www.google.com

This has nothing to do with Photon's momentums or other such high physics and is a simple phenomena.

You are right when you describe the operation of the usual low cost Crooke's Radiometer. With these, the gas flow effects dominate.

However, if you get one with a really good vacuum you will see the blades spin the opposite way, that is to say the white side is pushed harder than the black. The reason is that the light reflects from the white side, doubling the momentum from photons that strike that side, while the black side absorbs the photons, delivering only the momentum with no multiplier. This is what would happen in space, which is a very good vacuum.

A little internet research here reveals that Gold is full of it. First of all, if his thermodynamic explanation of "light pressure" is correct then the Crookes radiometer should stop rotating after a few seconds (once the black side reaches thermal equilibrium and the veins slow down under the influences of friction). Secondly the obvious question is this: If Reynold's explanation is INcorrect(and Gold is right) then the Crookes radiometer should rotate the "wrong" way even in a perfect vacuum. But guess what: Pyotr Lebedev did the experiment in 1901, creating a sufficiently good vacuum, and the thing rotated the "correct" way (according to the photon model of light). In sum, without resorting to complicated explanations of what is going on (Reynolds etc...) the experimental evidence clearly indicates that Gold is wrong.

Viewing a mirror in terms of thermodynamics is clearly a misconception. What I wonder is: How did this guy get to be quoted in New Scientist? Or should I not be wondering these things?

A Crookes' radiometer has four vanes suspended inside a glass bulb as you've described (see this picture). Inside the bulb, there is a good vacuum. When you shine a light on the vanes in the radiometer, they spin -- in bright sunlight, they can spin at several thousand rotations per minute!

The vacuum is important to the radiometer's success. If there is no vacuum (that is, if the bulb is full of air), the vanes do not spin because there is too much drag. If there is a near-perfect vacuum, the vanes do not spin unless they are held in a frictionless way. If the vanes have a frictionless support and the vacuum is complete, then photons bouncing off the silver side of the vanes push the vanes, causing them to rotate. However, this force is exceedingly small.

If there is a good but incomplete vacuum, then a different effect called thermal transpiration occurs along the edges of the vanes, as described on this page. The effect looks as though the light is pushing against the black faces. The black side of the vane moves away from the light.

The howstuffworks page has a link to an article which explains that with a perfect vacuum the thrust does seem to be generated by the reflective side. http://science.howstuffworks.com/framed.htm?parent =question239.htm&url=http://math.ucr.edu/home/baez /physics/General/LightMill/light-mill.html

For those who wonder what a radiometer is, Howstuffworks has pictures, explanation and a few links...

Excellent point. The "browser" stopped innovating as soon as they turned over control of navigation and content display to plug-ins.

I mean, what is "today"'s browser, but a JavaScript parser, Flash plug-in displayer, and Java engine. Oh, and every now and then people use it to mark up text, though you wouldn't guess it by the sheer number of images being tossed around...

As for innovation, we have text, images, links, and fonts all squared away... Visual ideas are tapped at the moment, so lets work on the other senses. How about some voice-activated navigation advances? Weren't we promised browsable smells?

"Mmm...alcohol fueled computer. One for you, one for me."

Considering that this computer runs on methanol and not ethanol, that would not be a particulary good idea.

This was predicted a while ago when patents were used as threats toward the Open Source community. If every idea in the world was to be patented tomorrow, what do you think would be the result? No, not anarchy, but definetly a breakdown in "the system" as we know it. More than likely after a few weeks or months of chaotic legal issues congress or some other form of government would step in and pass legislation changing how patents work. In the end though the Open Source community would be hit the hardest as they tend to be the most controversial source of innovation in technology.

Lots of open source works are illegal in many countries because they perform the same function as other works which are closed-source and either patented or copyrighted or both. This is a result of laws which restrict freedom of thought and speech in order to maintain the status quo and capitalism's roots: dominance over competition. The problem is, Open Source works were not meant to compete with other products or companies. When you put the GNU General Public Lisence on your software, the last thing on your mind should be whether or not you will be able to keep others from reproducing the work or taking and developing it into something different or better. Open Source is a springboard from which new innovation and technology can come from. Yet it is being abused and in some respects destroyed by the principles some governments operate upon.

When you patent something so simple and useful as web caching, you're cutting off the Open Source community and its users and developers from the freedom to express themselves. Who came up with one idea or another should have nothing to do with whether or not someone is allowd to take and use that idea. Essentially, patents are to the Open Source community as a muzzle is to freedom of speech.

HowStuffWorks' "How Patents Work" describes a benefit of patents for society: They help disseminate technological information to other inventors. When you apply for a patent, you are required to submit a detailed description of your invention. This description becomes part of the patent office's database, which is public record. Once the patent has expired, the idea is more readily available than it would have been if it had never been patented. The problem with this "dissemination of technological information" is that it takes 20 years in the USA for it to occur. That's 20 years longer than it should take. Inventors can't just take an idea and use it for another idea like with Open Source; instead an inventor would have to purchase a license to use the original idea in his newly spawned idea. This puts Open Source "inventors" at a significant disadvantage because a great amount of Open Source work is made free in the monetary sense of the word (i.e. gratis). Because of that, many Open Source developers don't have the funds to purchase a license and therefore can't use the original idea. Now, profit isn't completely foreign to Open Source works. The GNU General Public License specifically encourages people to profit from an Open Source work by charging money for its distribution. Of course under the terms of the GPL someone could simply purchase the product (and therefore a copy of the source) and then give it out freely to everyone else in the world. This is what some people in business and government do not understand and do not take advantage of. Immediately these people say "but then you can't make a profit because someone is already giving it away!" And so the government is supposed to make sure that NOBODY can simply 'give it away'? What then is to become of the Open Source works that are made by developers who don't have $3,000 to spend on a patent they don't want to restrict anyone from using or enforce anyone to obey? They're supposed to get fucked, that's what is to become of them. In the name of the executive, the legislative, and the judicial powers, Amen.

The idea of a patent is a great thing. Invent

I can understand spending the disk/cpu for lossless compression on, say, a 96khz classical recording, but most of what comes out of a live mix (or even a commercial rock studio recording) is just not worth the system resources. for live recordings, ogg at 256 or mp3 at 320 is more than enough, and small pipes and short CPUs are much happier.

Because we're talking about audiophiles here (who else would *complain* about the previous audio format on the Phish site). You know. These are the people who think they can hear the difference between a CD and a CD with green ink on it. The same people who insist that vinyl has higher fidelity than CD. The same people who compare the dry tonality of different digital interconnects.

Even supposedly decent sites make so many mistakes when discussing digital audio that they'd fail an undergrads signals course. "No information is lost" my arse. And what sort of nonsense is that idiot trying to pass off as a digital signal; don't these "experts" know what low-pass filtering means?

Audiophilia. It's a disease. Kill it before it spreads.

I wonder whether it is black or white which causes the pixels to "fade."

perhaps this story at howstuffworks.com got him a little bit too excitied

technically, no, he didn't rob the bank himself.

he just provided the guns, the get-away car, the combination to the vault, and the map of the exits.

This is a pretty lame analogy (as most are), but if you must use the bank robbery analogy, all he did was provide a list of banks that provided red suckers within 50 miles.

Where do you come up with guns, the get-away car, the vault combination and a map of the exits? His search engine was asked `where can I find this file?' and it responded.

Google itself is much more likely to provide a combination, a get-away car, Guns and an exit map. (All the links listed were given by google.)

After you've read that, you'll need to get additional information on rechargeable batteries. Note that that page talks about nickel oxide batteries but the information applies to lead acid batteries such as you find in a typical UPS (and cars, for that matter).

It is also crucial to understand that the battery is an electric, not an electronic, device. So there's no way for the battery itself to report to your server that it is getting low on power. You'll need some after-market monitoring electronics hooked on there that will sense how the battery is doing and will function as a middle man to your PC.

Another important issue is sinewave capability. If your UPS can't put out a sinewave voltage, you should probably avoid it.

Can anyone add anything to that?

Ok, heres some supporting evidence. You can follow my sources of research.

Source1

source3
source4
source5
source6 Warning Warnings

"Methylphenidate should not be used in children under 6 years of age, since safety and efficacy in this age group have not been established.

Although a causal relationship has not been established, suppression of growth (i.e. weight gain and/or height) has been reported with the long-term use of stimulants in children. Therefore, patients requiring long-term therapy should be carefully monitored. In addition, the use of "Drug Holidays" is recommended, that is, withholding the drug on weekends and during school holidays in as much as the clinical situation permits.

Methylphenidate should not be used for severe depression of either exogenous or endogenous origin. Clinical experience suggests that in psychotic children, administration of methylphenidate may exacerbate symptoms of behavior disturbance and thought disorder.

Methylphenidate should not be used for the prevention or treatment of normal fatigue states.
There is some clinical evidence that methylphenidate may lower the convulsive threshold in patients with prior history of seizures, with prior EEG abnormalities in absence of seizures and, very rarely, in patients with no prior EEG evidence nor history of seizures. Safe concomitant use of anticonvulsants and methylphenidate has not been established. In the presence of seizures, the drug should be discontinued. Use cautiously in patients with hypertension. Blood pressure should be monitored at appropriate intervals in all patients taking methylphenidate, especially those with hypertension."
source7a
source7b
source8

source9 Yet, "since the late 1990s, a spate of scientific research has begun to establish that adults do generate new brain cells in some regions of the brain, well into old age.

And now, for the first time, scientists have seen that new neurons become functional members of the brain, forging new connections and firing "action potentials" like any other neuron.

Although this latest discovery has only been observed in the brains of mice, the analogy to humans suggests that the rules of the card game have indeed changed. It also points toward new directions in potential therapies for neurological disorders or brain injuries."

Source10
"biologists at Princeton University have found that thousands of freshly born neurons arrive each day in the cerebral cortex, the outer rind of the brain where higher intellectual functions and personality are centered."

Ok, heres some supporting evidence. You can follow my sources of research.

Source1

source3
source4
source5
source6 Warning Warnings

"Methylphenidate should not be used in children under 6 years of age, since safety and efficacy in this age group have not been established.

Although a causal relationship has not been established, suppression of growth (i.e. weight gain and/or height) has been reported with the long-term use of stimulants in children. Therefore, patients requiring long-term therapy should be carefully monitored. In addition, the use of "Drug Holidays" is recommended, that is, withholding the drug on weekends and during school holidays in as much as the clinical situation permits.

Methylphenidate should not be used for severe depression of either exogenous or endogenous origin. Clinical experience suggests that in psychotic children, administration of methylphenidate may exacerbate symptoms of behavior disturbance and thought disorder.

Methylphenidate should not be used for the prevention or treatment of normal fatigue states.
There is some clinical evidence that methylphenidate may lower the convulsive threshold in patients with prior history of seizures, with prior EEG abnormalities in absence of seizures and, very rarely, in patients with no prior EEG evidence nor history of seizures. Safe concomitant use of anticonvulsants and methylphenidate has not been established. In the presence of seizures, the drug should be discontinued. Use cautiously in patients with hypertension. Blood pressure should be monitored at appropriate intervals in all patients taking methylphenidate, especially those with hypertension."
source7a
source7b
source8

source9 Yet, "since the late 1990s, a spate of scientific research has begun to establish that adults do generate new brain cells in some regions of the brain, well into old age.

And now, for the first time, scientists have seen that new neurons become functional members of the brain, forging new connections and firing "action potentials" like any other neuron.

Although this latest discovery has only been observed in the brains of mice, the analogy to humans suggests that the rules of the card game have indeed changed. It also points toward new directions in potential therapies for neurological disorders or brain injuries."

Source10
"biologists at Princeton University have found that thousands of freshly born neurons arrive each day in the cerebral cortex, the outer rind of the brain where higher intellectual functions and personality are centered."

Decaffinated coffee was discovered acctidentally (around the turn of the century, if I recall) when a ship loaded with coffee beans from South America was caught in a nasty storm. Its deck and hold were awash with sea water for 8+ hours. The owners of the cargo, attempting to salvage the beans, made coffee with it anyway. The taste was different, and analysis showed that it had less caffeine. They marketed it as "decaffeinated" coffee, and a product was born.

There are several chemicals that dissolve caffeine, and I assume sea water has some of them. Read up here for modern methods of decaffeination.

Personally, I like the taste of coffee, and it'd be kinda nice to have a no-caffeine variant that tasted the same as full-octane stuff. Great for having a cup before bed.

.

firewire is PTP not client to server.
USB 2.0, released in 2001 and becoming popular in 2002, is designed to offer performance similar to FireWire. USB 2.0 has a maximum data rate of 480 Mbps. Given that their speeds are now roughly identical, the big difference remaining between FireWire and USB 2.0 is that USB 2.0 is host-based, meaning that devices must connect to a computer in order to communicate. FireWire is peer-to-peer, meaning that two FireWire cameras can talk to each other without going through a computer.