Car radiators are so big that the surface area is enough to cool the "modest" power requirements of electronics without aditional fans.
Speak for your own electronics! *My* electronics dissipate 14kW into an open-loop water cooling system, and suck 40A at 208V three-phase. Yee-haw! Seriously though, there are plenty of electronics applications where even a large car radiator is insufficient for cooling. My argon laser (the above referenced 14kW heat-waster) is puny compared to the heat dissipation requirements of large industrial power converters, electron-beam welders, cutting and welding lasers, etc.
it wouldn't take a billion dollars to build a duplicate google system. It wouldn't even take a twentieth of that.
Really? They have a LOT of hardware. Lots of it. It's specialized, too, not all off-the-shelf stuff. More importantly, though, they have intagible assetts worth much more than their equipment -- code. Googlecode is about as non-trivial as it gets. To write it all, they have some of the smartest engineers in the world, and those engineers aren't cheap. Just as important as their technology itself, they have a massive user base that no other search engine can match without years of media exposure and word-of-mouth. They have an established reputation for fairness and avoidance of underhanded manipulation of results. I believe those factors make it impossible to compete with Google in the short term, even if their hardware and code could be replicated for a few hundred million dollars (a more likely figure than $50M).
Investors like short-term results. Try telling your VC's that they should invest $150M in a search engine project that replicates something already in existance, and won't be a moneymaker for at least 5 years. Think they'll bite?
That sounds much more like an issue with your computer than with your monitor. Does it do this with a CRT running the same resolution and refresh rate? I would bet so. LCDs have slower image response time (pixel rise/fall) than CRTs, but there is no significant delay between the time a signal reaches the monitor and the time it is displayed. In fact, implementing such a delay would be quite a challenge -- the information would have to be stored somewhere between the time it is sent to the monitor and the time it is displayed. This would require significant memory in the monitor to buffer several frames of video. Monitors don't do this.
Computing equipment *loves* cold, as long as you don't have to worry about condensation.
Ah, not so! *processor cores* love cold, not electronics in general. Specifically, electrolytic capacitors freeze and fail below their rated temperature, and it's really tough to find any that are rated to temps that low. Also, because of resistance, capacitance, and crystal frequency value changes at low temps, oscillators and filters tend not to behave. This doesn't even consider the issue of thermal expansion coefficient differences causing BGA chips to pop off the circuit boards! Making anything electronic operate in that environment is highly non-trivial.
Relatively high concentrations of ozone are remarkably effective at removing terrible odors from electronics. To make a long story short, our home was destroyed by toxic mold a few years ago. In the process of assessing the extent of damage, we tried everything possible to remove the stench from our goods. One thing we tried was ozone. After a week or so in a room full of rather high concentration (enough that you couldn't breathe it comfortably and it burns your eyes), things smelled fine -- for awhile. Unfortunately, it didn't kill all the mold, so it grew right back. Since your odors are a bit less tenacious than fungal mycotoxins, and since yours can't grow back spontaneously, I would bet ozone will fix the problem. Try contacting a local indoor air quality remediation company for rental of commecial ozone generators. If your handy with high voltage electronics, you can build an even better one yourself on the cheap (the technique is quite obvious to any high voltage experimentor). That's what I did. A small ozone generator left in the computer room indefinitely will also help neutralize any odors that remain. Good luck!
100k for 96 processors? Figure you can get a barebones system with 256 MB ram for around $250. That's $24k for the boxes, a 96-port switch, and some good clustering software.
Where's the rest of the cost coming from?
Notice that each individual processor has 2 gigs of ram plus a hard drive! Those are highly nontrivial costs -- more than the cost of the processor and custom 12-CPU motherboard. Also note that you pay for compactness. This is much smaller than a cluster of equivalent individual PCs, and therefore costs more.
Is nothing new - it's called corundum or as you more probably know it, sapphire (or ruby when it is red).
Actually, it is new. You are thinking of crystalline alumina, which is not a glass. Now, they have developed a way to make amorphous alumina (alumina glass), which is much easier to process for manufacture of everyday objects. Furthermore, the alumina glass is truly transparent when sintered or thermoformed, not merely translucent like sintered alumina. This means it can be used for demanding optical applications without going through the expensive and difficult crystal growth process.
Aluminum is light and Tough (high energy to break). It is also ductile (deforms before breaking) something that no ceramic is...
This isn't a ceramic -- that's the cool new part. It's a glass, and glasses can be far tougher and more impact resistant than ceramics.
As an aside, translucent alumina is used in something you see everyday - sodium vapor lamps use alumina to encapsulate the sodium metal that they use as their filament.
Those arc capsules are sintered crystalline alumina. Good stuff, but not a glass. With the new technique developed here, it should be possible to make stronger, cheaper arc capsules that perform better. Note that the sintered ceramic is transulcent (allows some light to pass through) while the glass is transparent (optical-quality material with no inherent scattering). Nitpick: high pressure sodium lamps don't have a filament -- they use an electrical discharge through vaporized sodium and argon to produce light.
"UL stress testing replicates a lot of the unimaginably stupid things users do to their devices."
Perhaps we need to reduce the rigorousness of our testing a bit and put the responsibility on users not to do so much stupid crap. Not everything needs to be drool-proof -- idiots deserve to be punished by having their newly purchased devices fail impressively when abused!
So I build a transmitter that operates on the WiFi band, but spews noise with 2000 watts of power through a massive antenna. Suddenly your WiFi is worthless. However there's nothing you can do, since there's no regulation. What I'm doing is legal, though assinie.
No, it's not legal. Even on unlicensed services, intentional interference is prohibited -- and enforced as thoroughly as technically possible. People go to jail every year for pulling crap like that.
A sufficiently powerful laser beam will ionize air due to the electric field strength within the beam. This can be achieved on a desktop scale with a small Q-switched YAG laser (I've done it). When the air ionizes, it begins to absorb the beam, which results in even more heating. You get what appears to be a spark floating in air. This is not wavelength dependent (except that field strength depends to some extent on wavelength), and is not related to the absorption of the beam by the gases in the air. In fact, at high enough intensities, the same effect occurs in a vacuum due to particle pair formation. Fun stuff.
But in actuality, basic physics says that magnetic forces can do no work.
Yes and no. A static magnetic field can do no work, since the path integral of the force vector applied to a magnetic dipole moving through the field is always zero. However, "permanent magnets" do store energy and can do work. It requires energy to align the magnetic dipoles in a ferromagnetic material. Thus, any chunk of material that is "magnetized" is storing potential energy in the form of a magnetic field. This energy can be extracted if the arrangement of the dipoles is randomized again. This is how the transformer in your computer power supply works. It is a "flyback mode converter". Electrical energy is used to magnetize the ferrite core of the transformer, which stores that energy for a fraction of a second. The energy is released when the core demagnetizes, and the change in magnetic field incudes a current/voltage in the secondary winding of the transformer.
My understanding is that they work mainly with pain compliance
You are decidely incorrect. Stun guns used to work that way, but newer ones definitely do not. They work by triggering widespread uncontrollable muscle rigidity. See the excellent examples(both demos and surveillance/news video) at: cool taser video page
I remember being told in several HV-safety courses in physics classes that the human cross-body resistance (index finger to index finger) is generally 100 kohms to 1 mohm
Yes and no. When measured with low voltages, the resistance is in that range, but almost all of that resistance is in the first.5mm or so of skin. High voltages (above a hundred volts or so) instantly break down this skin barrier, and the apparent resistance drops to a couple hundred ohms. This is why 120V can kill. A 5kV capacitor bank will likely explode body parts.
It is happening. I am posting this from a brand new computer my uncle (a truck driver) just bought for his family from a local computer shop. He paid "over $500" (refuses to say exactly how much), and was told it is comparable to a Dell Dimension 2400, Dell's $500 intro system with a P4 2.6, 128MB RAM, 40G HDD, CD-RW, 17" CRT. This box is a Duron 1.6, 96MB RAM, 40G HDD, plain CD drive, refurb 17" CRT. Comparable? No. Dishonest ripoff of an unsuspecting customer? Absolutely. I'll be having a word with the shop owner tomorrow. Seems he's gotten used to operating in a small rural Ohio town where nobody knows anything about computers and there are no other stores to compete with.
The courts have held repeatedly that there is a "right to link" without the permission of the target. Whether agreed to or not, their license agreement cannot prevent anyone from linking to their domain. The overreaching hyperbole that permeates these terms of service is so extreme that I would imagine a court would hold the entire agreement invalid.
Actually, not all Canon cameras use CF memory. I have a Canon SD-10, their smallest real digital camera. It is not physically large enough to use a CF card -- there isn't room. They chose SD instead. I was a bit disappointed, since I already have huge amounts of CF memory for my other cameras and MP3 players, but it's a compromise I'm wiling to make to have such a tiny camera.
Come on, now. Anyone who has taken a college class in modern physics has most of the know-how to build a fusion bomb. Anyone with a degree in physics is more than capable of doing all the necessary calculations to design one. This article provides very little assistance really. The difficult part is not the theory -- it's fairly simple. The challenge lies in the practicalities of actually making one. Obtaining the materials is nearly impossible for most nations, never mind for an individual! This precludes just about everyone except major governments from building them, and it's hard even for them. Successfully assembling one without dying of acute radiation poisoning requires advanced manufacturing facilities and equipment beyond the reach of any but the wealthiest experimenter. It's just not a hazard. *Think* before you decide to restrict information.
Since there are not many deaths in the amateur rocketry community, I'm fairly sure I know which incident this was. In fact, it is the only amateur-rocket-related death I know of. It is worth noting that the blast that killed him was apparently not the result of a chemical reaction, or even related to the fact that he was working on a rocket engine. It was a mechanical failure of a pressure vessel which threw shrapnel -- just like a steam boiler exploding in the 1800's.
For the love of particle physics, gamma radiation is NOT particulate
Sure it is. At gamma energies, wave-particle duality is a significant influence in the behavior of the radiation. It can be described as an EM wave, but gamma photons definitely exhibit particulate behavior as well.
"With their hardware, from the article:
"Average time to render one frame: 2 hours"
I guess that means slashdot nerds won't be able to make LOTR quality CG for sometime?"
That must be "2 processor-hours". With 1400 CG shots and 240 frames per shot minimum, that is at least 336k frames, and 672k hours of rendering. They would have had to start rendering in 1926. If you assume processor-hours, though, it drops to a much more reasonable 210 hours of total rendering time.
"Hmm... when I was taking UG Physics classes it was mentioned as being "impulse" or "shock""
"Shock" maybe, but "impulse" is a completely different, well-defined physics term -- force*time. If it can't be expressed in newton-seconds, no physics professor (or even high school teacher) should ever be caught calling it impulse. Jerk is also well-defined as both acceleration/time and force/time -- it's in the texts, it just doesn't get used much by physicists. Mechanical engineers use the force/time version of jerk quite a bit -- rate of loading is very important in most mechanical systems.
Actually, Christmas Islands already does something very similar to this. Try pigse.cx. You will end up at a "sitefinder"-like page from the Christmas Island TLD Authority which suggests that you register the domain, explaining that all unregistered domains in.cx are redirected to that page. It does not return NXDOMAIN, but there are no commercial advertisements (other than by C.I.) and no search function.
Hello? This "redundant" comment was posted four minutes *before* the apparent duplicate. For some reason, this one was modded down as redundant while the true dupe has risen to +5 funny!
Slashdot Mirror
But moment once who or which is " Deepz0ne "? (no meaning)!
Tell me about it! I have that problem all the time, man.
Methinks machine translation is still in its infancy.
Car radiators are so big that the surface area is enough to cool the "modest" power requirements of electronics without aditional fans.
Speak for your own electronics! *My* electronics dissipate 14kW into an open-loop water cooling system, and suck 40A at 208V three-phase. Yee-haw! Seriously though, there are plenty of electronics applications where even a large car radiator is insufficient for cooling. My argon laser (the above referenced 14kW heat-waster) is puny compared to the heat dissipation requirements of large industrial power converters, electron-beam welders, cutting and welding lasers, etc.
it wouldn't take a billion dollars to build a duplicate google system. It wouldn't even take a twentieth of that.
Really? They have a LOT of hardware. Lots of it. It's specialized, too, not all off-the-shelf stuff. More importantly, though, they have intagible assetts worth much more than their equipment -- code. Googlecode is about as non-trivial as it gets. To write it all, they have some of the smartest engineers in the world, and those engineers aren't cheap. Just as important as their technology itself, they have a massive user base that no other search engine can match without years of media exposure and word-of-mouth. They have an established reputation for fairness and avoidance of underhanded manipulation of results. I believe those factors make it impossible to compete with Google in the short term, even if their hardware and code could be replicated for a few hundred million dollars (a more likely figure than $50M).
Investors like short-term results. Try telling your VC's that they should invest $150M in a search engine project that replicates something already in existance, and won't be a moneymaker for at least 5 years. Think they'll bite?
That sounds much more like an issue with your computer than with your monitor. Does it do this with a CRT running the same resolution and refresh rate? I would bet so. LCDs have slower image response time (pixel rise/fall) than CRTs, but there is no significant delay between the time a signal reaches the monitor and the time it is displayed. In fact, implementing such a delay would be quite a challenge -- the information would have to be stored somewhere between the time it is sent to the monitor and the time it is displayed. This would require significant memory in the monitor to buffer several frames of video. Monitors don't do this.
Computing equipment *loves* cold, as long as you don't have to worry about condensation.
Ah, not so! *processor cores* love cold, not electronics in general. Specifically, electrolytic capacitors freeze and fail below their rated temperature, and it's really tough to find any that are rated to temps that low. Also, because of resistance, capacitance, and crystal frequency value changes at low temps, oscillators and filters tend not to behave. This doesn't even consider the issue of thermal expansion coefficient differences causing BGA chips to pop off the circuit boards! Making anything electronic operate in that environment is highly non-trivial.
Relatively high concentrations of ozone are remarkably effective at removing terrible odors from electronics. To make a long story short, our home was destroyed by toxic mold a few years ago. In the process of assessing the extent of damage, we tried everything possible to remove the stench from our goods. One thing we tried was ozone. After a week or so in a room full of rather high concentration (enough that you couldn't breathe it comfortably and it burns your eyes), things smelled fine -- for awhile. Unfortunately, it didn't kill all the mold, so it grew right back. Since your odors are a bit less tenacious than fungal mycotoxins, and since yours can't grow back spontaneously, I would bet ozone will fix the problem. Try contacting a local indoor air quality remediation company for rental of commecial ozone generators. If your handy with high voltage electronics, you can build an even better one yourself on the cheap (the technique is quite obvious to any high voltage experimentor). That's what I did. A small ozone generator left in the computer room indefinitely will also help neutralize any odors that remain. Good luck!
100k for 96 processors? Figure you can get a barebones system with 256 MB ram for around $250. That's $24k for the boxes, a 96-port switch, and some good clustering software.
Where's the rest of the cost coming from?
Notice that each individual processor has 2 gigs of ram plus a hard drive! Those are highly nontrivial costs -- more than the cost of the processor and custom 12-CPU motherboard. Also note that you pay for compactness. This is much smaller than a cluster of equivalent individual PCs, and therefore costs more.
Is nothing new - it's called corundum or as you more probably know it, sapphire (or ruby when it is red).
Actually, it is new. You are thinking of crystalline alumina, which is not a glass. Now, they have developed a way to make amorphous alumina (alumina glass), which is much easier to process for manufacture of everyday objects. Furthermore, the alumina glass is truly transparent when sintered or thermoformed, not merely translucent like sintered alumina. This means it can be used for demanding optical applications without going through the expensive and difficult crystal growth process.
Aluminum is light and Tough (high energy to break). It is also ductile (deforms before breaking) something that no ceramic is...
This isn't a ceramic -- that's the cool new part. It's a glass, and glasses can be far tougher and more impact resistant than ceramics.
As an aside, translucent alumina is used in something you see everyday - sodium vapor lamps use alumina to encapsulate the sodium metal that they use as their filament.
Those arc capsules are sintered crystalline alumina. Good stuff, but not a glass. With the new technique developed here, it should be possible to make stronger, cheaper arc capsules that perform better. Note that the sintered ceramic is transulcent (allows some light to pass through) while the glass is transparent (optical-quality material with no inherent scattering). Nitpick: high pressure sodium lamps don't have a filament -- they use an electrical discharge through vaporized sodium and argon to produce light.
And the difference between this and a cruise missile is what exactly?
Cruise missiles are *supposed* to crash!
"UL stress testing replicates a lot of the unimaginably stupid things users do to their devices."
Perhaps we need to reduce the rigorousness of our testing a bit and put the responsibility on users not to do so much stupid crap. Not everything needs to be drool-proof -- idiots deserve to be punished by having their newly purchased devices fail impressively when abused!
So I build a transmitter that operates on the WiFi band, but spews noise with 2000 watts of power through a massive antenna. Suddenly your WiFi is worthless. However there's nothing you can do, since there's no regulation. What I'm doing is legal, though assinie.
No, it's not legal. Even on unlicensed services, intentional interference is prohibited -- and enforced as thoroughly as technically possible. People go to jail every year for pulling crap like that.
A sufficiently powerful laser beam will ionize air due to the electric field strength within the beam. This can be achieved on a desktop scale with a small Q-switched YAG laser (I've done it). When the air ionizes, it begins to absorb the beam, which results in even more heating. You get what appears to be a spark floating in air. This is not wavelength dependent (except that field strength depends to some extent on wavelength), and is not related to the absorption of the beam by the gases in the air. In fact, at high enough intensities, the same effect occurs in a vacuum due to particle pair formation. Fun stuff.
But in actuality, basic physics says that magnetic forces can do no work.
Yes and no. A static magnetic field can do no work, since the path integral of the force vector applied to a magnetic dipole moving through the field is always zero. However, "permanent magnets" do store energy and can do work. It requires energy to align the magnetic dipoles in a ferromagnetic material. Thus, any chunk of material that is "magnetized" is storing potential energy in the form of a magnetic field. This energy can be extracted if the arrangement of the dipoles is randomized again. This is how the transformer in your computer power supply works. It is a "flyback mode converter". Electrical energy is used to magnetize the ferrite core of the transformer, which stores that energy for a fraction of a second. The energy is released when the core demagnetizes, and the change in magnetic field incudes a current/voltage in the secondary winding of the transformer.
My understanding is that they work mainly with pain compliance
You are decidely incorrect. Stun guns used to work that way, but newer ones definitely do not. They work by triggering widespread uncontrollable muscle rigidity. See the excellent examples(both demos and surveillance/news video) at: cool taser video page
I remember being told in several HV-safety courses in physics classes that the human cross-body resistance (index finger to index finger) is generally 100 kohms to 1 mohm
.5mm or so of skin. High voltages (above a hundred volts or so) instantly break down this skin barrier, and the apparent resistance drops to a couple hundred ohms. This is why 120V can kill. A 5kV capacitor bank will likely explode body parts.
Yes and no. When measured with low voltages, the resistance is in that range, but almost all of that resistance is in the first
It is happening. I am posting this from a brand new computer my uncle (a truck driver) just bought for his family from a local computer shop. He paid "over $500" (refuses to say exactly how much), and was told it is comparable to a Dell Dimension 2400, Dell's $500 intro system with a P4 2.6, 128MB RAM, 40G HDD, CD-RW, 17" CRT. This box is a Duron 1.6, 96MB RAM, 40G HDD, plain CD drive, refurb 17" CRT. Comparable? No. Dishonest ripoff of an unsuspecting customer? Absolutely. I'll be having a word with the shop owner tomorrow. Seems he's gotten used to operating in a small rural Ohio town where nobody knows anything about computers and there are no other stores to compete with.
The courts have held repeatedly that there is a "right to link" without the permission of the target. Whether agreed to or not, their license agreement cannot prevent anyone from linking to their domain. The overreaching hyperbole that permeates these terms of service is so extreme that I would imagine a court would hold the entire agreement invalid.
Actually, not all Canon cameras use CF memory. I have a Canon SD-10, their smallest real digital camera. It is not physically large enough to use a CF card -- there isn't room. They chose SD instead. I was a bit disappointed, since I already have huge amounts of CF memory for my other cameras and MP3 players, but it's a compromise I'm wiling to make to have such a tiny camera.
Come on, now. Anyone who has taken a college class in modern physics has most of the know-how to build a fusion bomb. Anyone with a degree in physics is more than capable of doing all the necessary calculations to design one. This article provides very little assistance really. The difficult part is not the theory -- it's fairly simple. The challenge lies in the practicalities of actually making one. Obtaining the materials is nearly impossible for most nations, never mind for an individual! This precludes just about everyone except major governments from building them, and it's hard even for them. Successfully assembling one without dying of acute radiation poisoning requires advanced manufacturing facilities and equipment beyond the reach of any but the wealthiest experimenter. It's just not a hazard. *Think* before you decide to restrict information.
Since there are not many deaths in the amateur rocketry community, I'm fairly sure I know which incident this was. In fact, it is the only amateur-rocket-related death I know of. It is worth noting that the blast that killed him was apparently not the result of a chemical reaction, or even related to the fact that he was working on a rocket engine. It was a mechanical failure of a pressure vessel which threw shrapnel -- just like a steam boiler exploding in the 1800's.
For the love of particle physics, gamma radiation is NOT particulate
Sure it is. At gamma energies, wave-particle duality is a significant influence in the behavior of the radiation. It can be described as an EM wave, but gamma photons definitely exhibit particulate behavior as well.
"With their hardware, from the article: "Average time to render one frame: 2 hours" I guess that means slashdot nerds won't be able to make LOTR quality CG for sometime?"
That must be "2 processor-hours". With 1400 CG shots and 240 frames per shot minimum, that is at least 336k frames, and 672k hours of rendering. They would have had to start rendering in 1926. If you assume processor-hours, though, it drops to a much more reasonable 210 hours of total rendering time.
Actually, Christmas Islands already does something very similar to this. Try pigse.cx. You will end up at a "sitefinder"-like page from the Christmas Island TLD Authority which suggests that you register the domain, explaining that all unregistered domains in .cx are redirected to that page. It does not return NXDOMAIN, but there are no commercial advertisements (other than by C.I.) and no search function.
Hello? This "redundant" comment was posted four minutes *before* the apparent duplicate. For some reason, this one was modded down as redundant while the true dupe has risen to +5 funny!