Aluminum wire instead of copper for winding the transformer coil would reduce the weight, although the size would remain the same.
An aluminum wire has higher resistance than a copper wire with the same cross section. Because of this, transformers would have to be made out of a thicker wire which would mean bigger and (probably) heavier transformers.
Also aluminum is a lot cheaper than copper so I don't think cost would be a problem.
The opening has a magnetized torid ring around it. Using the right hand rule (...) you create an electrical flow around the metal torid ring. The resulting magnetic field 'pulls' the ions through the ring, resulting in propulsion.
High school physics.
The force exerted on the charged particles by the magnetic field is always perpendicular to their velocity. Charged particles in a magnetic field move with a constant speed. Because of this ion engines use an electric field to accelerate ions.
I don't think catalysators help with nitrogen oxides. Catalysators work by speeding up the oxidation not preventing it.
That is good in the case of cars because a lot gas does not burn entirely (into water and carbon dioxide) in a piston engine. Resulting unstable aromatic compounds, carbon monoxide and stuff like that can be poisonous (some aromatic compounds are also proven to cause cancer). Catalysators help remove these poisons by literary burning them.
On the other hand, nitrogen oxides (at least NO2, I don't know about the others) are stable compounds which means that you would have to provide energy to turn them back to nitrogen and oxygen.
In 50 years, I hope we have airplanes fueled by hydrogen produced in nuclear facilities.
Burning hydrogen in conventional jet engines is not as environmentaly friendly as you may think. Hydrogen burns at temperatures that are high enough for nitrogen in air to combine with oxygen. The resulting nitrogen oxides cause acid rain and other nasty things. Also introduction of water vapour into the higher atmosphere is considered one of the causes for the global warming.
The only way to over come this is to use rocket engines - and this won't happen for some time because you have to take all of the oxygen with you.
When you consider how much biomatter would have to have been tied up in swamps and then covered in just the right ways and held at just the right pressures and temperatures to produce the amount of oil and coal we've already pulled out of the ground, and how inefficient that process would have to have been, the "fossil" explanation becomes pretty unlikely.
Do you know that all limestone (and some similar types of rock) on earth was produced by various oceanic organisms? The shells of these organisms (for example tiny algae) were subjected to just the right pressure and temperatures to form a solid rock. The amount of rock produced this way is enormous (Alps, Himalayas, etc. are all made out this stuff).
Life has been on earth for a long time. Don't underestimate what microorganisms can do if they have a billion years to do it.
One of the remote root exploits for ssh that came out this september only worked, if ssh wasn't using privilege separation. Unfortunately libpam-opie doesn't work with this setting enabled.
So if I would stick with my old password and privilege separation (that is enabled by default) my box wouldn't get rooted. Sometimes OPIE can make more problems than it solves.
All the matter consist of the particles which are combinations of quarks.
Ordinary matter (like you and me) is composed of barions and leptons. Leptons are not composed of quarks. Same for neutrinos, which are a bit less ordinary, but still count as matter.
As barions provide most of the total mass of an atom, the best you can say is that most of the matter is made of quarks.
The article is full of buzzwords (anybody care to explain what is a ultrasonic motor in this context?) and fails to mention the biggest problem with tiny robots: the power source.
I can't find anything that resembles a battery on the schematic. There is a small light blue blob on the bottom of the prototype on the photograph though. But at 3 watts of consumption I don't believe it can fly for very long.
On the other hand, you can see a thin wire going from the prototype, behind the fingers and out of the picture. Perhaps Epson forgot to mention, that their prototype must be wired to a nuclear power plant to provide power for the power-saving bluetooth module...
Probably no one is talking about that because everyone knows that a comet exploded in the Jovian atmosphere. The energy released there was way beyond anything those pounds of Pu could do.
The article you are linking tells how the jovian atmosphere could compress that pile of Pu like the explosives in the nuclear bomb. It is not that simple.
To achieve a chain reaction that would cause an explosion you need to compress plutonium in a fraction of a second.
The plutonium battery that is falling through the atmosphere would be only slowly squeezed (if it manages to stay in one piece in the first place). If it achieves the right pressure it could become above critical but that does not automatically mean an explosion. It just means that the pile will slowly heat up. The temperatures at the depth this would occur are way higher than those that would be caused by the (slow) chain reaction in the Galileo's battery.
Just do "dd if=/dev/hd?? of=image.bin". To restore, us "dd if=image.bin of=/dev/hd??". Works with any filesystem, just make sure the source and destination partitions are the same size.
I've used that many times. Guys from IT department always thought I was using a port of Norton Ghost for Linux.
So you can't tell if a "pattern" is alive unless you expose it to a "destructive obstacle"?
Bacteria will take no better attempts to survive than a forest fire. One is considered alive the other is not. How do you tell which one by your definition?
On the other hand, an electric current (a pattern of moving electrons if you will) through a coil will fiercely attempt its continuance when confronted by a destructive obstacle - you will get a nice spark if you break the circuit. Again, we don't consider electron currents to be alive.
Did you know that a single atom of uranium when fissioned will give of the amount of energy that is needed to lift a hair one millimeter above ground?
And only a part of this energy is converted to a gamma ray photon. As harmless as this may sound, this photon is perfectly capable of hitting the right spot on a DNA molecule in your brain.
It will transfer only a part of its energy to the molecule, but it could do enough damage to overcome cells repair mechanisms and start a tumor.
Now I don't believe that cell phones are dangerous. But the amount of energy microwaves carry has very little to do with that.
As far as I can see, my laptop has height, width and depth. So it's 3D, right? Does that mean that we can expect thicker laptops in the future (that are of course more 3D than thin ultra portables we can see today?)
actually an LCD screen placed on top of a conventional monitor.
This is a really clever idea. Now I can see how they managed to get that real 3D feel. Using a conventional CRT monitor in a laptop certainly adds some third dimension.
Now I can see what they are planning to do:
1. Use CRT monitor in a laptop
2. CRT monitors are cheaper than LCD panels, but laptop with CRT is more 3D, so it can be more expensive than conventional thin ones
3....
4. PROFIT!!:)
About an hour ago I had a discussion with my father about how LED or fluorescent lamps probably do not save as much power as advertised. Before you start talking about how little power gets converted to visible light in a normal light bulb, let me explain this further:
An incandescent light bulb is an ordinary resistor, which means that the current it draws from the net is in phase with voltage and sinus in shape.
LED and those little flourescent lamps are different. They need a rectifier to work (or are rectifiers themselves). This means that the current they draw is some ugly shape that only remotely resembles sinus. This means that this current contains a large proportion of higher harmonics (e.g. current that has 100, 150, 200, etc. Hz, ask Mr. Fourier). While your house meter may show less used kWh, these higher harmonics will cause bigger losses at your local transformer. Why? Because losses in transformer core rise with the square of frequency.
Computers with their switching power supplies already cause a lot of this kind of problems. If everyone would begin using LED lamps it would get much worse and power savings would not be that significant (they would only move from your house to transformers and power stations)
"The chances of you actually playing in a way, by luck only, that matches one of those (counting) strategies is almost nil," Soltys said. "It may match up after 20 hands, but after 100, there's no chance that it's just luck."
"The chances of a gambler actually winning the jackpot on our slot machines is almost nil. They may get some minor wins, but when they strike a jackpot, there's no chance that it's just luck"
Seriously, why do casinos allow games (like blackjack) that can be cheated by counting the cards and knowing some laws of probability? It's like running software that has a known exploit and just hunting down crackers that know how use it instead of fixing the software.
When wiring up electrical outlets, if you reverse the hot and the neutral lines, you actually create a voltage potential between the outlets.
I don't know about your country, but here in Europe you can connect a stove to an electrical outlet in two ways (connector can be turned 180 degrees). This way, there is no guarantee which line to the stove will be "hot" and which will be "neutral". Because of this, it is equally unimportant if the "hot" wire is connected to the left or the right pin in the outlet.
The surface of an electrical machine should never be connected to the neutral wire anyhow. That is why there is a third line ("ground") available.
I believe either your refrigerator or your stove is a shock hazard and should be replaced.
They'd need to break the arc using compressed air blown across the gap, or by submerging the contacts so the arc couldn't form in the first place.
That are exactly the countermeasures that are used today on normal circuit breakers. Why then waste millions on technology that doesn't bring any improvement?
no semiconductor could handle the power losses
I agree with that. It was a typo. I meant superconductors.
At a guess, since they "valve" the current rather than just chopping it
I don't believe they can "valve" anything. If you heat superconductor above the critical temperature it loses superconductivity in an instant. They say the material used is made of bismuth, strontium, calcium, copper and oxygen. That is probably some kind of ceramic superconductor. And ceramic superconductors are insulators above critical temperature. That means instant cut off.
Even if they would somehow manage to gradually increase the resistance of their rods, imagine trying to "valve" a circuit at several 100kV and several 100A with a resistor. You would have enormous power loses on the "valve". No sane amount of liquid nitrogen will be enough to cool that.
When large currents are involved, there are only two states possible: switched on or off. No valving.
Allowing larger electricity flows through substations without fear of overpowering the circuit breakers would let power companies move more energy through the grid
Ccircuit brakers are not limiting the amount of electrical power that can flow through a high-voltage line
The diameter of cables limits the current and the distance between cables limits the voltage. Lines are designed for a specific capacity. You can't upgrade them only by chaging the breaker.
Besides, they say that a normal circuit breaker would arc across. What would prevent an arc between the ends of their ceramic rods?
If they want to use semiconductors, why don't they use them for the entire line? Or for the coils in the generators? That would make a difference, not some circuit brakers...
I don't really know how it is done in USA, but in Europe the frequency is very carefully controlled by Quartz oscillators. A lot of clocks here use the frequency of the grid to keep time so it has to be accurate. Also a lot of measuring equipment only works correctly at 50 Hz
About regulating the speed of a huge turbine: Virtually all big power plants use synchronous generators. That means that they do not need to be mechanically regulated. The generator will do that for you (and with great accuracy).
A "common source" of sync is a "base" group of the most powerful powerplants. Together they can make very minute corrections to the grid frequency.
Slashdot Mirror
Aluminum wire instead of copper for winding the transformer coil would reduce the weight, although the size would remain the same.
An aluminum wire has higher resistance than a copper wire with the same cross section. Because of this, transformers would have to be made out of a thicker wire which would mean bigger and (probably) heavier transformers.
Also aluminum is a lot cheaper than copper so I don't think cost would be a problem.
The opening has a magnetized torid ring around it. Using the right hand rule (...) you create an electrical flow around the metal torid ring. The resulting magnetic field 'pulls' the ions through the ring, resulting in propulsion.
High school physics.
The force exerted on the charged particles by the magnetic field is always perpendicular to their velocity. Charged particles in a magnetic field move with a constant speed. Because of this ion engines use an electric field to accelerate ions.
I don't think catalysators help with nitrogen oxides. Catalysators work by speeding up the oxidation not preventing it.
That is good in the case of cars because a lot gas does not burn entirely (into water and carbon dioxide) in a piston engine. Resulting unstable aromatic compounds, carbon monoxide and stuff like that can be poisonous (some aromatic compounds are also proven to cause cancer). Catalysators help remove these poisons by literary burning them.
On the other hand, nitrogen oxides (at least NO2, I don't know about the others) are stable compounds which means that you would have to provide energy to turn them back to nitrogen and oxygen.
In 50 years, I hope we have airplanes fueled by hydrogen produced in nuclear facilities.
Burning hydrogen in conventional jet engines is not as environmentaly friendly as you may think. Hydrogen burns at temperatures that are high enough for nitrogen in air to combine with oxygen. The resulting nitrogen oxides cause acid rain and other nasty things. Also introduction of water vapour into the higher atmosphere is considered one of the causes for the global warming.
The only way to over come this is to use rocket engines - and this won't happen for some time because you have to take all of the oxygen with you.
Don't use wood if you care about fire safety... Cabinets for electronics are made out of metal for a reason.
Transcode supports a lot of codecs (MPEG-1 and MPEG-2 included). I've mentioned MPEG-1 because tmpgenc.net says that TMPGEnc is a MPEG-1 encoder.
I don't know about TMPGEnc, but I've used Transcode to make some VCD and SVCDs. I think the quality is as good as any other MPEG1 encoder.
This would be very handy to me, since I use XP for Video
...
...
:)
Transcode,
Cinelerra,
Photo Editing,
Gimp,
Gaming
Nethack
Try again... What do you need windows for?
When you consider how much biomatter would have to have been tied up in swamps and then covered in just the right ways and held at just the right pressures and temperatures to produce the amount of oil and coal we've already pulled out of the ground, and how inefficient that process would have to have been, the "fossil" explanation becomes pretty unlikely.
Do you know that all limestone (and some similar types of rock) on earth was produced by various oceanic organisms? The shells of these organisms (for example tiny algae) were subjected to just the right pressure and temperatures to form a solid rock. The amount of rock produced this way is enormous (Alps, Himalayas, etc. are all made out this stuff).
Life has been on earth for a long time. Don't underestimate what microorganisms can do if they have a billion years to do it.
One of the remote root exploits for ssh that came out this september only worked, if ssh wasn't using privilege separation. Unfortunately libpam-opie doesn't work with this setting enabled.
So if I would stick with my old password and privilege separation (that is enabled by default) my box wouldn't get rooted. Sometimes OPIE can make more problems than it solves.
All the matter consist of the particles which
are combinations of quarks.
Ordinary matter (like you and me) is composed of barions and leptons. Leptons are not composed of quarks. Same for neutrinos, which are a bit less ordinary, but still count as matter.
As barions provide most of the total mass of an atom, the best you can say is that most of the matter is made of quarks.
The article is full of buzzwords (anybody care to explain what is a ultrasonic motor in this context?) and fails to mention the biggest problem with tiny robots: the power source.
I can't find anything that resembles a battery on the schematic. There is a small light blue blob on the bottom of the prototype on the photograph though. But at 3 watts of consumption I don't believe it can fly for very long.
On the other hand, you can see a thin wire going from the prototype, behind the fingers and out of the picture. Perhaps Epson forgot to mention, that their prototype must be wired to a nuclear power plant to provide power for the power-saving bluetooth module...
Probably no one is talking about that because everyone knows that a comet exploded in the Jovian atmosphere. The energy released there was way beyond anything those pounds of Pu could do.
The article you are linking tells how the jovian atmosphere could compress that pile of Pu like the explosives in the nuclear bomb. It is not that simple.
To achieve a chain reaction that would cause an explosion you need to compress plutonium in a fraction of a second.
The plutonium battery that is falling through the atmosphere would be only slowly squeezed (if it manages to stay in one piece in the first place). If it achieves the right pressure it could become above critical but that does not automatically mean an explosion. It just means that the pile will slowly heat up. The temperatures at the depth this would occur are way higher than those that would be caused by the (slow) chain reaction in the Galileo's battery.
You can make an image of a partition using dd.
Just do "dd if=/dev/hd?? of=image.bin". To restore, us "dd if=image.bin of=/dev/hd??". Works with any filesystem, just make sure the source and destination partitions are the same size.
I've used that many times. Guys from IT department always thought I was using a port of Norton Ghost for Linux.
So you can't tell if a "pattern" is alive unless you expose it to a "destructive obstacle"?
Bacteria will take no better attempts to survive than a forest fire. One is considered alive the other is not. How do you tell which one by your definition?
On the other hand, an electric current (a pattern of moving electrons if you will) through a coil will fiercely attempt its continuance when confronted by a destructive obstacle - you will get a nice spark if you break the circuit. Again, we don't consider electron currents to be alive.
I've read a story somewhere (perhaps on slashdot) that someones garage door remote stoped working after he/she installed a case window.
Did you know that a single atom of uranium when fissioned will give of the amount of energy that is needed to lift a hair one millimeter above ground?
And only a part of this energy is converted to a gamma ray photon. As harmless as this may sound, this photon is perfectly capable of hitting the right spot on a DNA molecule in your brain.
It will transfer only a part of its energy to the molecule, but it could do enough damage to overcome cells repair mechanisms and start a tumor.
Now I don't believe that cell phones are dangerous. But the amount of energy microwaves carry has very little to do with that.
As far as I can see, my laptop has height, width and depth. So it's 3D, right? Does that mean that we can expect thicker laptops in the future (that are of course more 3D than thin ultra portables we can see today?)
actually an LCD screen placed on top of a conventional monitor.This is a really clever idea. Now I can see how they managed to get that real 3D feel. Using a conventional CRT monitor in a laptop certainly adds some third dimension.
Now I can see what they are planning to do:
1. Use CRT monitor in a laptop2. CRT monitors are cheaper than LCD panels, but laptop with CRT is more 3D, so it can be more expensive than conventional thin ones
3.
4. PROFIT!!
About an hour ago I had a discussion with my father about how LED or fluorescent lamps probably do not save as much power as advertised. Before you start talking about how little power gets converted to visible light in a normal light bulb, let me explain this further:
An incandescent light bulb is an ordinary resistor, which means that the current it draws from the net is in phase with voltage and sinus in shape.
LED and those little flourescent lamps are different. They need a rectifier to work (or are rectifiers themselves). This means that the current they draw is some ugly shape that only remotely resembles sinus. This means that this current contains a large proportion of higher harmonics (e.g. current that has 100, 150, 200, etc. Hz, ask Mr. Fourier). While your house meter may show less used kWh, these higher harmonics will cause bigger losses at your local transformer. Why? Because losses in transformer core rise with the square of frequency.
Computers with their switching power supplies already cause a lot of this kind of problems. If everyone would begin using LED lamps it would get much worse and power savings would not be that significant (they would only move from your house to transformers and power stations)
"The chances of a gambler actually winning the jackpot on our slot machines is almost nil. They may get some minor wins, but when they strike a jackpot, there's no chance that it's just luck"
Seriously, why do casinos allow games (like blackjack) that can be cheated by counting the cards and knowing some laws of probability? It's like running software that has a known exploit and just hunting down crackers that know how use it instead of fixing the software.
I don't know about your country, but here in Europe you can connect a stove to an electrical outlet in two ways (connector can be turned 180 degrees). This way, there is no guarantee which line to the stove will be "hot" and which will be "neutral". Because of this, it is equally unimportant if the "hot" wire is connected to the left or the right pin in the outlet.
The surface of an electrical machine should never be connected to the neutral wire anyhow. That is why there is a third line ("ground") available.
I believe either your refrigerator or your stove is a shock hazard and should be replaced.
That are exactly the countermeasures that are used today on normal circuit breakers. Why then waste millions on technology that doesn't bring any improvement?
no semiconductor could handle the power lossesI agree with that. It was a typo. I meant superconductors.
I don't believe they can "valve" anything. If you heat superconductor above the critical temperature it loses superconductivity in an instant. They say the material used is made of bismuth, strontium, calcium, copper and oxygen. That is probably some kind of ceramic superconductor. And ceramic superconductors are insulators above critical temperature. That means instant cut off.
Even if they would somehow manage to gradually increase the resistance of their rods, imagine trying to "valve" a circuit at several 100kV and several 100A with a resistor. You would have enormous power loses on the "valve". No sane amount of liquid nitrogen will be enough to cool that.
When large currents are involved, there are only two states possible: switched on or off. No valving.
Ccircuit brakers are not limiting the amount of electrical power that can flow through a high-voltage line
The diameter of cables limits the current and the distance between cables limits the voltage. Lines are designed for a specific capacity. You can't upgrade them only by chaging the breaker.
Besides, they say that a normal circuit breaker would arc across. What would prevent an arc between the ends of their ceramic rods?
If they want to use semiconductors, why don't they use them for the entire line? Or for the coils in the generators? That would make a difference, not some circuit brakers...
I don't really know how it is done in USA, but in Europe the frequency is very carefully controlled by Quartz oscillators. A lot of clocks here use the frequency of the grid to keep time so it has to be accurate. Also a lot of measuring equipment only works correctly at 50 Hz
About regulating the speed of a huge turbine: Virtually all big power plants use synchronous generators. That means that they do not need to be mechanically regulated. The generator will do that for you (and with great accuracy).
A "common source" of sync is a "base" group of the most powerful powerplants. Together they can make very minute corrections to the grid frequency.