If they need it accurate and traceable they'd have to pay a lab to calibrate it after it was fixed. Such a lab would reject it due to it being fixed (and charge a pretty penny with no calibrated scope at the end of the process.) So they're stuck.
(This reminds me of a story my wife tells about a lab PC that had a bad case of infant mortality. The local techs wanted to fix it themselves. She pointed out it was still in warranty - so the thing to do was send it back for fix-or-replace for free, rather than void the warranty and maybe end up with a broken machine and nothing (but wasted engineer time) to show for it.
Fixing a scope adequately for home use is another matter. Then, if you ever need serious accuracy, you can do the same sort of compensation hacks that were done back in the tube days, when stuff drifted all the time and you couldn't just have a lab tune up anything complicated and expect it to stay tuned.
When the patent/copyright runs out on "magically levitating giant stone blocks into pyramid shapes" sometime in the future, I think we're going to have a heck of a lot of fun.
There's no particular mystery to how they did it - without magical levitation.
It's interesting to pull a few blocks off a pyramid. You find inscriptions on them that say things like:
There was a way to do this that didn't involve unsoldering and measuring the resistors.
Tests with an ohmmeter and visual inspection had already shown that the charger tied each D line to an independent voltage divider across the supplied voltage. This produces the (Thevenin) equivalent of:
- a voltage source at the same ratio to the supply voltage that the lower resistor's value has to the sum of the resistors' values,
- in series with a(n equivalent series) resistance equal to that of the two resistors in parallel.
Measuring the supply voltage and the unloaded voltage on a D line gives the resistor value ratio. You can measure the parallel equivalent resistance by either of two methods:
- Shut down the supply, short + and -, and measure the resistance from the D line to the shorted supply.
- Load the D line with a resistor to ground of known value that pulls the voltage down appreciably. (In the ballpark of cutting it in half is ideal.) Measure the amount it droops (and recheck the power supply voltage in case you pulled that down a bit, too.) This presumes the pullup resistor can handle 2x the normal current and 4x the normal power dissipation, for the duration of the test.
With those two measurements you can calculate the resistor values. If they fall near standard values it provides a sanity check on your calculations and measurements. You only have to pull 'em off if there's an additional "black box" component hooked to the D lines that might foul up your measurements.
(Of course if you already have the tools handy, pulling off and measuring the resistors may be easier. It also lets you check that there wasn't something else hidden in the circuit that you missed.)
Proprietary connectors are NOT "clever", they're generally asinine and should be considered criminal unless a DAMNED fine case can be made each time.
Sometimes it's (literally) criminal to use standard connectors. Example: Antenna connectors of type-approved devices (WiFi, cellphone, etc.). The radio regulatory bodies of a number of countries required the manufacturers to use proprietary connectors (and not sell them generally) to make it difficult for users to attach high-gain directional antennas or external signal boosters that might make the device exceed the country's emitted signal levels. (Of course the manufacturers had a financial disincentive to build models with standard connectors for other markets. So things were hard for modders until the inevitable marketing of mating connectors by third parties.)
Of course that isn't the situation with Apple's charging system. But just thought I'd mention it in case anybody was fuming about a radio device.
Even if the communications look like noise, they will raise the noise floor over the normal cosmic background radiation. No matter how the signal is encoded, the RF power will be detectable. All we would need to look for is bright spots in the sky where the "noise" floor is higher than normal.
Given that noise just looks like something hot and the universe has a LOT of stars and other hot stuff lying about (including a star near every planet habitable by "life as we know it"), looking for places where "the 'noise' floor is higher than normal" doesn't produce an effective rule for separating a radio-using civilization from other radiating cosmic objects.
Haven't read TFA but I don't think a solar sail ship could propel itself by shining a light into its own sails. Equal-and-opposite reaction and all that; the light source would try to propel the ship backwards and what photons hit the sail would propel it forward. Imagine trying to propel a fan boat by directing the fan into a parasail -- the sail would just be a drag. You can't lift yourself up by your own bootstraps. You'd do better shining the light out into space.
Given that the light would bounce off the sail it would not cancel (as in the fan/sail case) but serve as a thrust when the light reflects backward off the sail. The forward thrust on the sail would be about twice that of the backward thrust on the craft.
While you'd get essentially the same thrust firing the laser toward the rear, it would all be thrust on the craft, none on the sail. So there might be times when it makes sense to shoot the sail. Like the one below...
I believe what is being described in the summary is using LCDs to reflect photons hitting the sides of the ship into the sails at an angle, to generate torque. The LCDs are adjustable reflectors in this case.
It sounds to me like they're using it to switch areas of the sail to diffuse reflection. This reduces the thrust by scattering the reflected light in a range of directions (some of them partially canceling others) rather than reflecting it essentially straight back. By having, say, the right side of the sail develop less thrust than the left, you turn the sail to the right. It's not "on the edge" as in right ON the edge. But it's an area of the sail adjacent to the edge in order to get the most leverage from a given area of LCD material.
You could achieve the same effect by bouncing a laser (or other light source) off a patch near one side of the sail. But that would take kilowatts per square meter to get thrust equivalent to full sun at earth's orbital distance. Why burn such amounts of power when you can just modulate the sunlight you've already got hitting the sail?
Come on, you have to admit that's a pretty clever design element.
I agree. It's brilliant. (No pun intended, though one is available.)
(Downsides: You need to keep 'em from freezing (or design 'em to survive it) and you probably need to build the actuators as a large number of independent units, so a meteorite puncture or other damage doesn't take too much of the control area out of service (or "stick" it in an undesired mode).)
Imagine if the entire sail surface could be selectively modulated in this way.
Though it would improve the maneuverability it would drastically increase the sail's mass, thus decreasing its performance for propulsion. You only want enough of this to accomplish the control necessary for the mission profile.
having 5 minute recharge was needed to get away from the battery-swapping trick,
Two other things about it:
- Rapid recharge means you can capture more of the energy from regenerative braking for later use. Braking pulls energy from the car MUCH faster than acceleration adds it (because you can load ALL the tires to just under the point where they lose traction.) You'd like to capture maybe 400+ HP to use later. That's about a third of a megawatt.
- The rapid charge is possible because the battery structure has very low losses due to very low internal resistance and other parasitics. This means the batteries don't slag down if you drive extreme currents into them. But it also means they don't overheat when you pull extreme currents from them. And the two together mean that the batteries are VERY efficient at storing power - giving back nearly all you put in rather than burning it into heat.
So the design improvement that gives you fast charge also gives you high acceleration, rapid regenerative braking, and high energy efficiency as a bonus.
What some groups do is create polycrystalline lumps where each crystal has a slightly different formula. Then they test resistivity with changing temperature across the whole lot. If just one crystal superconducts, there will be a 'kink' in the graph. This is like a simple brute-force method for testing many samples in parallel, but doesn't necessarily provide a formula that an be produced in bulk.
Once you've got a lump containing one or more crystals that superconduct, grind it up and wave a magnet at it. Catch any that jump away.
Superconductors tend to lose superconductivity in the presence of a large magnetic field, limiting the amount of current they can carry.
Type I yes. Type II no.
The latter makes current whirlpools that pinch the magnetic field into little quantized columns, which arrange themselves in a hexagonal grid. Superconduction quits in the narrow column where the mag field penetrates, but continues just fine in the rest of the material, dodging around the columns. The field must be very strong to make a lattice of mag field penetrations so dense that they merge and all superconduction crosswise to the mag field quits.
Not that it matters:
Superconductors are useful for a LOT of stuff besides carrying power around. Being able to make thin-film superconductor elements with a critical temperature, not just of an air conditioned room, but of a human body with a moderately high fever, would be very useful. (You could keep it cool enough to keep working, even inside a piece of hot equipment on a hot day, with a Peltier junction cooler. No problem.)
Would you want to talk to your friend orbiting Saturn with an hour delay at each end? Send a message, wait 2 hours, get a reply, reply back, wait 2 hours, etc. Yes, it's doable, but if non-radio based technology presented itself that would make for quicker communications, that would be rapidly adopted.
Such a faster-than-light communication medium would seem to violate fundamental physical laws as currently understood. In particular: If the speed of light was beaten by enough to usefully improve on lightspeed message latency at planetary distances, the technology would also enable the construction of a rather simple machine for sending useful messages from the future to the past - violating causality. (Also: If information can do it, matter probably can, too. Warp 5, Mr. Sulu!)
So I expect that the normal mode of rapid communication at interplanetary-and-larger distances to be electromagnetic - radio, light, etc. - despite the delay. It would be the best that can be done, barring a fundamental physics breakthrough of an all-bets-are-off magnitude.
I once read somewhere that the easiest way to tell there's something unusual about our solar system is to notice that an otherwise unremarkable G-class main sequence star is a powerful radio emitter.
Problem is that, once the radio emissions look like noise, the emissions from a sun-plus-inhabited-planet(s)-and-spacecraft solar system just look like it has a lot of stuff - like an accretion disk / asteroid belt in a near-sun orbit - heated to a nice, radio-noisy, temperature. Maybe the energy vs. frequency distribution wouldn't be quite thermal. But even that wouldn't necessarily be particularly noticeable (or distinct from various other natural phenomena, like a multiple-ring system or band-slotting from resonant absorption) at galactic distances.
There'd be nothing particularly surprising, or interesting, about finding such things in the sky.
Also melanin. Mammals without fur and/or light colored skin get the shaft. Of sunlight.
Melanin helps a lot but it's far from a perfect shield. (For starters, some light has to make it through to avoid rickets through lack of sunlight-catalyzed vitamin D synthesis if the diet isn't rich in D {and similar problems with vitamin A deficiency} - which is why those branches of humanity that lived more poleward for a few hundred generations switched to only light-triggered melanin production or just lost the ability to tan {except in spots} at all.)
Dark-skinned people still get sun-damage-genetic-noise skin diseases. They just don't get them as often.
My own take on the Fermi paradox comes from the observation that modern radio communication systems - spread spectrum and ODFM - approach the Shannon limit of the bandwidth's information carrying capacity. As they do that, they approach the appearance of pure noise.
Earlier transmission systems, such as AM, FM, and analog broadcast's AM/FM hybrid, involve massive inherent reundancy and low bandwidth utilization. This makes their existence detectable (even if not fully decodable) at interstellar distances and at the resulting far worse signal-to-noise ratio than their intended receivers experience. Spread-spectrum and OFDM systems (and no doubt others yet to be invented) fill their assigned bandwidth with a close approximation to white noise, with only a small amount of redundancy to allow the receiver to detect the existence of the signal and synchronize with it. (Even the redundancy from the forward error correction is sufficiently complex that at appears as noise if the particular scheme is not being looked for.) This is why, when the signal-to-noise ratio of a digital signal becomes excessive, the reception drops out completely rather than becoming noisy.
Bandwidth is limited by physice, but the potential valuable uses of it are limited only by imagination and cost. So other radio-using civilizations seem likely to follow a similar path of squeezing as much information as technology allows into their signals.
If this is the case, the L term in the Drake equation ("the length of time such civilizations release detectable signals into space") becomes a measure, not of the lifetime of the civilization after it begins to use broadcast radio, but of the time from such use to the time it is supplanted by highly-efficient but not-readily-detectable shannon-limit-approaching signals.
When estimating the number of intelligences in this galaxy using the Drake equation, L was ballparked at 10,000 years. But consider broadcast TV here on Earth (the main telltale, emitting far more power per station than audio radio): Excluding early experiments the first regularly scheduled TV broadcasts started in 1930 - and the Analog Cutoff (where most high-power analog TV stations were shut down to free the bandwidth for other purposes) is in progress now, with the US terminating all full-power analog TV broadcast in 2009, just 80 years after the first signals from that first broadcast-service station.
So I have no feeling of loneliness just because we haven't happened to hear any civilizations in the narrow time slot when they might send DETECTABLE broadcasts.
... we're actively implementing patches on the month-behind schedule, and this includes our control systems too. We can do this because every server type (data ack, database, human interface server, etc) we have operates in tandem with an identical twin, in standard failover configuration. So we patch the backup, and initiate a controlled failover to it. Problem? Fail back. Works? Patch the other side now.
And doing it this way creates windows of time when YOU HAVE NO backup:
1) From the time you start the upgrade on the backup until you have completed the controlled failover and discovered it to work, then
2) From the time you start until the time you finish the upgrade of the former primary system, or
3) From the time you start the upgrade on the backup until the time you have finished rolling it back.
This may be enough to achieve the requisite length of the string of 9s in your reliability requirements. But for some applications it seems too risky to me - especially given that one mistake in the upgrade could accidentally take out the running control system when the backup was unavailable.
To avoid this you need THREE systems in a double failover configuration. Then you can upgrade one and still have a primary and backup live.
Induction couples to the magnetic field from the current through the wire.
You can also couple to the electric field emerging from the wire and extending toward the other wires, the ground, and surrounding space in general.
Both are inverse-first-power (because the wire is a line/cylinder - approximately "infinite" at the scale of the device - rather than a point/sphere).
Coupling to the mag field requires current to be flowing. Even if there is no load on the line there will be some reactive current flowing to transformers downstream, and if you're just coupling to the current you don't care if you're in-phase with the voltage or not. (You'll shift the phase to induce a little extra resistive loss in the line due to the power you pull with your coupling.) If the "feet" of the "bird" gripping the wire are a cylinder of transformer core material you'll couple very strongly.
Coupling to the electrical field can also be done because the field is very strong near the wire so the "body" of the "bird" is at a significantly different voltage than its "feet". This will drive a current through the "legs" if there is a load connected between the feet and body. The current will be limited by the capacitance of the body to the local ground.
... even if the version on the R410 was branded OpenManage(TM) and the firmware may have been a different code base.
Seems to me the only thing new here is that somebody pre-tweaked the code in the shipping firmware load so they, in addition to the authorized IT department, have the necessary keys to "remotely administer" your box, avoiding having to break the stock load's crypto.
Any bets on whether the NSA already has their own way in? Or the Chinese espionage aparatus ditto?
AMT ("Advanced Management Technology") is why I'm not buying Intel-based machines - and when my employer surplussed the old laptops I bought one that was three generations back - adequate, and the last model without a remote-administration "feature".
(I still don't understand why I see lots of Slashdot articles flaming DRM "features", but the remote administration "features" never rise above the noise level - despite being EXPLICITLY a mechanism whose sole purpose is to undetectably and unblockably take COMPLETE CONTROL of the box, spying and/or modifying to any extent desired, rather than just to hobble some of its apps.)
I think geography does a pretty good job explaining why the U.S. remained relatively neutral.
IMHO a more likely cause was that the US population was more of German descent than English.
The NAZIs were hoping that the US would come in on THEIR side. And they had quite a number of supporters in the US power structure and media. Some of them apparently launched a plot to stage a fascist coup against Roosevelt. (This fell through because they picked the wrong guy for the military figurehead - Smedley Butler - who turned them in.)
Slashdot Mirror
o you have a dog that just decided it enjoys gnawing on human extremities while they are not moving. Good dog!
Bet it didn't smell like "my person" but more like "a parasite attacking my person".
Not really.
If they need it accurate and traceable they'd have to pay a lab to calibrate it after it was fixed. Such a lab would reject it due to it being fixed (and charge a pretty penny with no calibrated scope at the end of the process.) So they're stuck.
(This reminds me of a story my wife tells about a lab PC that had a bad case of infant mortality. The local techs wanted to fix it themselves. She pointed out it was still in warranty - so the thing to do was send it back for fix-or-replace for free, rather than void the warranty and maybe end up with a broken machine and nothing (but wasted engineer time) to show for it.
Fixing a scope adequately for home use is another matter. Then, if you ever need serious accuracy, you can do the same sort of compensation hacks that were done back in the tube days, when stuff drifted all the time and you couldn't just have a lab tune up anything complicated and expect it to stay tuned.
When the patent/copyright runs out on "magically levitating giant stone blocks into pyramid shapes" sometime in the future, I think we're going to have a heck of a lot of fun.
There's no particular mystery to how they did it - without magical levitation.
It's interesting to pull a few blocks off a pyramid. You find inscriptions on them that say things like:
"We DID IT! - Tiger Team Eight."
I was wondering why all the people getting onto the bus were caucasian, myself.
I assumed they used an animation tool that happened to have a library of mainly Caucasian figures.
There was a way to do this that didn't involve unsoldering and measuring the resistors.
Tests with an ohmmeter and visual inspection had already shown that the charger tied each D line to an independent voltage divider across the supplied voltage. This produces the (Thevenin) equivalent of:
- a voltage source at the same ratio to the supply voltage that the lower resistor's value has to the sum of the resistors' values,
- in series with a(n equivalent series) resistance equal to that of the two resistors in parallel.
Measuring the supply voltage and the unloaded voltage on a D line gives the resistor value ratio. You can measure the parallel equivalent resistance by either of two methods:
- Shut down the supply, short + and -, and measure the resistance from the D line to the shorted supply.
- Load the D line with a resistor to ground of known value that pulls the voltage down appreciably. (In the ballpark of cutting it in half is ideal.) Measure the amount it droops (and recheck the power supply voltage in case you pulled that down a bit, too.) This presumes the pullup resistor can handle 2x the normal current and 4x the normal power dissipation, for the duration of the test.
With those two measurements you can calculate the resistor values. If they fall near standard values it provides a sanity check on your calculations and measurements. You only have to pull 'em off if there's an additional "black box" component hooked to the D lines that might foul up your measurements.
(Of course if you already have the tools handy, pulling off and measuring the resistors may be easier. It also lets you check that there wasn't something else hidden in the circuit that you missed.)
Proprietary connectors are NOT "clever", they're generally asinine and should be considered criminal unless a DAMNED fine case can be made each time.
Sometimes it's (literally) criminal to use standard connectors. Example: Antenna connectors of type-approved devices (WiFi, cellphone, etc.). The radio regulatory bodies of a number of countries required the manufacturers to use proprietary connectors (and not sell them generally) to make it difficult for users to attach high-gain directional antennas or external signal boosters that might make the device exceed the country's emitted signal levels. (Of course the manufacturers had a financial disincentive to build models with standard connectors for other markets. So things were hard for modders until the inevitable marketing of mating connectors by third parties.)
Of course that isn't the situation with Apple's charging system. But just thought I'd mention it in case anybody was fuming about a radio device.
Even if the communications look like noise, they will raise the noise floor over the normal cosmic background radiation. No matter how the signal is encoded, the RF power will be detectable. All we would need to look for is bright spots in the sky where the "noise" floor is higher than normal.
Given that noise just looks like something hot and the universe has a LOT of stars and other hot stuff lying about (including a star near every planet habitable by "life as we know it"), looking for places where "the 'noise' floor is higher than normal" doesn't produce an effective rule for separating a radio-using civilization from other radiating cosmic objects.
He's not just late, he's dead you insensitive clod!
I hope being dead doesn't become a requirement for selling 1M eBook units.
Haven't read TFA but I don't think a solar sail ship could propel itself by shining a light into its own sails. Equal-and-opposite reaction and all that; the light source would try to propel the ship backwards and what photons hit the sail would propel it forward. Imagine trying to propel a fan boat by directing the fan into a parasail -- the sail would just be a drag. You can't lift yourself up by your own bootstraps. You'd do better shining the light out into space.
Given that the light would bounce off the sail it would not cancel (as in the fan/sail case) but serve as a thrust when the light reflects backward off the sail. The forward thrust on the sail would be about twice that of the backward thrust on the craft.
While you'd get essentially the same thrust firing the laser toward the rear, it would all be thrust on the craft, none on the sail. So there might be times when it makes sense to shoot the sail. Like the one below...
I believe what is being described in the summary is using LCDs to reflect photons hitting the sides of the ship into the sails at an angle, to generate torque. The LCDs are adjustable reflectors in this case.
It sounds to me like they're using it to switch areas of the sail to diffuse reflection. This reduces the thrust by scattering the reflected light in a range of directions (some of them partially canceling others) rather than reflecting it essentially straight back. By having, say, the right side of the sail develop less thrust than the left, you turn the sail to the right. It's not "on the edge" as in right ON the edge. But it's an area of the sail adjacent to the edge in order to get the most leverage from a given area of LCD material.
You could achieve the same effect by bouncing a laser (or other light source) off a patch near one side of the sail. But that would take kilowatts per square meter to get thrust equivalent to full sun at earth's orbital distance. Why burn such amounts of power when you can just modulate the sunlight you've already got hitting the sail?
Ironically the DECT industry group and the GSM association is made of largely of the same companies...
So perhaps the first hackers' group had a superior approach? I don't recally ever reading about it - perhaps that was part of the success?
I suspect the cellphone case has more government regulation of the protocols that would have to be tweaked.
Come on, you have to admit that's a pretty clever design element.
I agree. It's brilliant. (No pun intended, though one is available.)
(Downsides: You need to keep 'em from freezing (or design 'em to survive it) and you probably need to build the actuators as a large number of independent units, so a meteorite puncture or other damage doesn't take too much of the control area out of service (or "stick" it in an undesired mode).)
Imagine if the entire sail surface could be selectively modulated in this way.
Though it would improve the maneuverability it would drastically increase the sail's mass, thus decreasing its performance for propulsion. You only want enough of this to accomplish the control necessary for the mission profile.
...when does my laptop get one?
The wikipedia article says that, on July 7, Toshiba announced a prototype laptop battery using the same technology.
That was two days before TFA about the car battery appeared in Gizmag. (Perhaps they were both announced the same day?)
having 5 minute recharge was needed to get away from the battery-swapping trick,
Two other things about it:
- Rapid recharge means you can capture more of the energy from regenerative braking for later use. Braking pulls energy from the car MUCH faster than acceleration adds it (because you can load ALL the tires to just under the point where they lose traction.) You'd like to capture maybe 400+ HP to use later. That's about a third of a megawatt.
- The rapid charge is possible because the battery structure has very low losses due to very low internal resistance and other parasitics. This means the batteries don't slag down if you drive extreme currents into them. But it also means they don't overheat when you pull extreme currents from them. And the two together mean that the batteries are VERY efficient at storing power - giving back nearly all you put in rather than burning it into heat.
So the design improvement that gives you fast charge also gives you high acceleration, rapid regenerative braking, and high energy efficiency as a bonus.
What some groups do is create polycrystalline lumps where each crystal has a slightly different formula. Then they test resistivity with changing temperature across the whole lot. If just one crystal superconducts, there will be a 'kink' in the graph. This is like a simple brute-force method for testing many samples in parallel, but doesn't necessarily provide a formula that an be produced in bulk.
Once you've got a lump containing one or more crystals that superconduct, grind it up and wave a magnet at it. Catch any that jump away.
Superconductors tend to lose superconductivity in the presence of a large magnetic field, limiting the amount of current they can carry.
Type I yes. Type II no.
The latter makes current whirlpools that pinch the magnetic field into little quantized columns, which arrange themselves in a hexagonal grid. Superconduction quits in the narrow column where the mag field penetrates, but continues just fine in the rest of the material, dodging around the columns. The field must be very strong to make a lattice of mag field penetrations so dense that they merge and all superconduction crosswise to the mag field quits.
Not that it matters:
Superconductors are useful for a LOT of stuff besides carrying power around. Being able to make thin-film superconductor elements with a critical temperature, not just of an air conditioned room, but of a human body with a moderately high fever, would be very useful. (You could keep it cool enough to keep working, even inside a piece of hot equipment on a hot day, with a Peltier junction cooler. No problem.)
Would you want to talk to your friend orbiting Saturn with an hour delay at each end? Send a message, wait 2 hours, get a reply, reply back, wait 2 hours, etc. Yes, it's doable, but if non-radio based technology presented itself that would make for quicker communications, that would be rapidly adopted.
Such a faster-than-light communication medium would seem to violate fundamental physical laws as currently understood. In particular: If the speed of light was beaten by enough to usefully improve on lightspeed message latency at planetary distances, the technology would also enable the construction of a rather simple machine for sending useful messages from the future to the past - violating causality. (Also: If information can do it, matter probably can, too. Warp 5, Mr. Sulu!)
So I expect that the normal mode of rapid communication at interplanetary-and-larger distances to be electromagnetic - radio, light, etc. - despite the delay. It would be the best that can be done, barring a fundamental physics breakthrough of an all-bets-are-off magnitude.
I once read somewhere that the easiest way to tell there's something unusual about our solar system is to notice that an otherwise unremarkable G-class main sequence star is a powerful radio emitter.
Problem is that, once the radio emissions look like noise, the emissions from a sun-plus-inhabited-planet(s)-and-spacecraft solar system just look like it has a lot of stuff - like an accretion disk / asteroid belt in a near-sun orbit - heated to a nice, radio-noisy, temperature. Maybe the energy vs. frequency distribution wouldn't be quite thermal. But even that wouldn't necessarily be particularly noticeable (or distinct from various other natural phenomena, like a multiple-ring system or band-slotting from resonant absorption) at galactic distances.
There'd be nothing particularly surprising, or interesting, about finding such things in the sky.
Also melanin. Mammals without fur and/or light colored skin get the shaft. Of sunlight.
Melanin helps a lot but it's far from a perfect shield. (For starters, some light has to make it through to avoid rickets through lack of sunlight-catalyzed vitamin D synthesis if the diet isn't rich in D {and similar problems with vitamin A deficiency} - which is why those branches of humanity that lived more poleward for a few hundred generations switched to only light-triggered melanin production or just lost the ability to tan {except in spots} at all.)
Dark-skinned people still get sun-damage-genetic-noise skin diseases. They just don't get them as often.
This is the first time I see a self grammar Nazi.
You obviously haven't been paying attention to my posts. B=)
My own take on the Fermi paradox comes from the observation that modern radio communication systems - spread spectrum and ODFM - approach the Shannon limit of the bandwidth's information carrying capacity. As they do that, they approach the appearance of pure noise.
Earlier transmission systems, such as AM, FM, and analog broadcast's AM/FM hybrid, involve massive inherent reundancy and low bandwidth utilization. This makes their existence detectable (even if not fully decodable) at interstellar distances and at the resulting far worse signal-to-noise ratio than their intended receivers experience. Spread-spectrum and OFDM systems (and no doubt others yet to be invented) fill their assigned bandwidth with a close approximation to white noise, with only a small amount of redundancy to allow the receiver to detect the existence of the signal and synchronize with it. (Even the redundancy from the forward error correction is sufficiently complex that at appears as noise if the particular scheme is not being looked for.) This is why, when the signal-to-noise ratio of a digital signal becomes excessive, the reception drops out completely rather than becoming noisy.
Bandwidth is limited by physice, but the potential valuable uses of it are limited only by imagination and cost. So other radio-using civilizations seem likely to follow a similar path of squeezing as much information as technology allows into their signals.
If this is the case, the L term in the Drake equation ("the length of time such civilizations release detectable signals into space") becomes a measure, not of the lifetime of the civilization after it begins to use broadcast radio, but of the time from such use to the time it is supplanted by highly-efficient but not-readily-detectable shannon-limit-approaching signals.
When estimating the number of intelligences in this galaxy using the Drake equation, L was ballparked at 10,000 years. But consider broadcast TV here on Earth (the main telltale, emitting far more power per station than audio radio): Excluding early experiments the first regularly scheduled TV broadcasts started in 1930 - and the Analog Cutoff (where most high-power analog TV stations were shut down to free the bandwidth for other purposes) is in progress now, with the US terminating all full-power analog TV broadcast in 2009, just 80 years after the first signals from that first broadcast-service station.
So I have no feeling of loneliness just because we haven't happened to hear any civilizations in the narrow time slot when they might send DETECTABLE broadcasts.
... we're actively implementing patches on the month-behind schedule, and this includes our control systems too. We can do this because every server type (data ack, database, human interface server, etc) we have operates in tandem with an identical twin, in standard failover configuration. So we patch the backup, and initiate a controlled failover to it. Problem? Fail back. Works? Patch the other side now.
And doing it this way creates windows of time when YOU HAVE NO backup:
1) From the time you start the upgrade on the backup until you have completed the controlled failover and discovered it to work, then
2) From the time you start until the time you finish the upgrade of the former primary system, or
3) From the time you start the upgrade on the backup until the time you have finished rolling it back.
This may be enough to achieve the requisite length of the string of 9s in your reliability requirements. But for some applications it seems too risky to me - especially given that one mistake in the upgrade could accidentally take out the running control system when the backup was unavailable.
To avoid this you need THREE systems in a double failover configuration. Then you can upgrade one and still have a primary and backup live.
Induction couples to the magnetic field from the current through the wire.
You can also couple to the electric field emerging from the wire and extending toward the other wires, the ground, and surrounding space in general.
Both are inverse-first-power (because the wire is a line/cylinder - approximately "infinite" at the scale of the device - rather than a point/sphere).
Coupling to the mag field requires current to be flowing. Even if there is no load on the line there will be some reactive current flowing to transformers downstream, and if you're just coupling to the current you don't care if you're in-phase with the voltage or not. (You'll shift the phase to induce a little extra resistive loss in the line due to the power you pull with your coupling.) If the "feet" of the "bird" gripping the wire are a cylinder of transformer core material you'll couple very strongly.
Coupling to the electrical field can also be done because the field is very strong near the wire so the "body" of the "bird" is at a significantly different voltage than its "feet". This will drive a current through the "legs" if there is a load connected between the feet and body. The current will be limited by the capacitance of the body to the local ground.
... they'll probably end up paying a flat rate per in-commission drone.
... even if the version on the R410 was branded OpenManage(TM) and the firmware may have been a different code base.
Seems to me the only thing new here is that somebody pre-tweaked the code in the shipping firmware load so they, in addition to the authorized IT department, have the necessary keys to "remotely administer" your box, avoiding having to break the stock load's crypto.
Any bets on whether the NSA already has their own way in? Or the Chinese espionage aparatus ditto?
AMT ("Advanced Management Technology") is why I'm not buying Intel-based machines - and when my employer surplussed the old laptops I bought one that was three generations back - adequate, and the last model without a remote-administration "feature".
(I still don't understand why I see lots of Slashdot articles flaming DRM "features", but the remote administration "features" never rise above the noise level - despite being EXPLICITLY a mechanism whose sole purpose is to undetectably and unblockably take COMPLETE CONTROL of the box, spying and/or modifying to any extent desired, rather than just to hobble some of its apps.)
I think geography does a pretty good job explaining why the U.S. remained relatively neutral.
IMHO a more likely cause was that the US population was more of German descent than English.
The NAZIs were hoping that the US would come in on THEIR side. And they had quite a number of supporters in the US power structure and media. Some of them apparently launched a plot to stage a fascist coup against Roosevelt. (This fell through because they picked the wrong guy for the military figurehead - Smedley Butler - who turned them in.)