Is it asking too much that SlashDot do a teeensy bit of math before endorsing this idea?
Let's do some rough math:
15% of 115,000 is close to $17K. Assume a 5% mortgage, that's $862 more you have to pay during the first year. For that much, you could buy about 100 Megawatt-hrs of power. The solar system apparently generates "up to 3.5KW" of power, let's say optimistically that's 1KW average, assuming things happen there like clouds, night, angled sun, DC/AC conversion inefficiencies. That's 8.7 megawatt hrs. The solar power costs about TWELVE TIMES AS MUCH as utility power. Assuming you don't use all of that kilowatt (hard to believe, that's less than it takes to run a moderate sized AC), and you sell the "excess" to the power company, and they pay you their cost of generation, you're getting back LESS THAN A TWENTIETH OF WHAT THE POWER COSTS YOU TO GENERATE. And oh, if there were a LOT of these solar-powered houses, we'd have to build MORE GAS-BURNING peak-load generating plants, to handle the load the solar cells shrug off during cloudy weather, nighttime, storms...
Holy bleepin deity, can't anybody do a little math anymore?
Er, um, you're about 20% correct. Chemical explosions top out around 10,000 degrees, barely 1/1000th the temp required. They don't use "numerous" fission explosions, one will do, you just reflect the radiation around so it's coming from all sides. The neutron bomb didnt use chemical explosives, just a regular fission bomb with the parameters juggled for maximum radiation and minimum blast. Even so there was still about 30% blast effects. Pu is totally worthless nowdays, the US has about 18 tons of excess Pu that it would like to get rid of, the Russians likewise.. We may have to build several billion dollar reactors just to burn up the excess Pu.
This is all fine and good if you can string a short unbroken fiber cable from endpoint to endpoint, one with very little attenuation so there's a good chance each little photon will get thru to the other end.
The catch is the photon has to go from one end to the other while making NO impact on the Universe. The first time it makes a nudge in the time-space continum, it loses its magical quantum state.
That makes it really hard to say, route messages, as the act of inspecting the message is going to ruin its quantum goodness.
IANAL, but:
"whose principle content is music."
Is that a homopo, or did the original agreement really use that word?
In which case the agreement may be meaningless...
Any on ANY??
I think I still have a CDC Cyber 172 system dump tape under the raised floor....
So if they're right I can run NOS 1.3 and PLATO on an old Apple ][ ?
We had a small house fire which deposited tons of oily soot everywhere. Sort of like having 10,000 people smoke in your house for a year.
The semi-professional house-restoration folks scrubbed the walls with various liquids, which got most of the gunk off, then they brought in these high-falootin ozone generator boxes. A few hours of ozone and the smells were all gone.
*But* anything made of rubber fell apart, and *all* the ball point pens dried up. Oil in door hinges siezed up.
Assuming there's rubber or similar parts in the computers, and oil in various fan and disk bearings, I would NOT recommend this very effective treatment.
Let's not go overboard here folks:
* If this is like most school districts, there's very little informed planning. The computers are unlikely to be well-suited to the environment or to the new power source. Ideally the computers would have been chosen for low power consumption, with laptop-like design. Probably didnt happen, they're probably standard approx 200-watt Ac powered designs.
* Solar power is unlikely to be the best way to go. 200 watts of solar power is going to cost THOUSANDS of $, and may only last a few years in challenging environments. A little cow-methane powered generator might be MUCH cheaper and completely locally sustainable (no shortage of cow dung and small motorcycle engines.)
So MicroSoft is going to index files for us?
Let's look at their record:
* A Start menu thingy "find" that is slow, mostly broken, and doesnt have the smarts to not search.DLL and.EXE files or their own DllPrefetch or Cookie or system32 directories when I'm looking for plain text.
* A background file indexing thingie that seems to take forever.
From these brain-dead search folks you're expecting something GOOD?
*
I see it now, IBM buys SCO, so now they're suing themselves. They "settle" for, say $1B, which they pay to themselves AND deduct it too. Brilliant scheme!
IMHO the name "Atlas" has been kept going as a marketing ploy.
The current "Atlas" is as much an "Atlas" as twisted pair Ethernet is the original "garden hose coax" Ethernet.
The Atlas has been re-giggered over the years until the only part in common is the concept of using very flimsy pressurized tanks as structural elements.
Everything else, engines, boosters, upper stages have all been radically changed several times over.
And the reason the success rate was mentioned may be to counteract the Atlas's poor early reliability... Something like 30 big kabooms in the first 35 launches.
You'd think an article in a pub titled "New Scientist" would have at least ONE relevant number, such as the magnet strength, remanence, permittivity, maybe even a B-H curve? But Noooo.....
Seriously, only the BEST magnetic materials are suitable for hard disk surfaces, and there's not even a hint that this organic stuff has ANY of the required specs.
Looks great in a demo, but lots of hard to overcome obstacles, real show-stoppers:
(1) COST-- How many people will pay an extra $X,000 to fix what's a non-problem for many drivers? Is this enough volume to bring the cost down to reasonable levels?
(2) Reliability-- Any system that involves that many amps is going to have a certain failure rate in the driver electronics. It's possible the legal liabilities may make the system untenable.
(3) We're talking major watts of heat dissipation here. The actuators may be able to handle the occasional swerve or bump, but can they handle 60 minutes of washboard road? Not likely without an active liquid cooling loop.
(4) False alarms. If this is like most systems of this kind they have ultrasonic or laser sensors to look at upcoming bumps. Works fine on a clean dry road. But add water, snow, blowing dust, or blowing plastic bags, and the sensor is likely to "see" a big obstacle and command an abrupt "wheel up" command. Very nasty induced bump!
(5) Lack of driver feedback. If the system hides road conditions from the driver, they may easily end up going waaay too fast for road conditions. Everything will be fine until the system gets to 100%, then all heck might break loose as the wheels lose traction. Airplanes have to be specifically designed by law to give plenty of warning before getting into dangerous parts of the performance envelope. It's time this requirement apply to autos also.
(6) Noise. Notice the movies are silent! How much noise do the actuators make, and is this noise less irritating than a little body lean?
This may be a technology that's always really neat looking from afar, but not worth it once all the drawbacks are considered.
Havent we had objects in orbit for 40+ yrs now, many positioned in just the right orbits to transit thru the moon's shadow? Satellites like the GPS series, whose positions are known and tracked to the centimeter?
Why hasnt this effect, if it exists, been noticed 1000's of times?
Guess I'm a quibbler, but:
(1) Cold water has been used for decades for cooling. The first major mall in the USA, Southdale, in Mpls, has been cooled by cold well water for oh, a bit over half a century.
(2)" 8,000 homes - the equivalent of 32 million square feet". I don't know about Ontario, but around here the average home is under 2,000 sq feet, not 4,000. And piping cold water around to every house is unlikely to be cost-effective.
(3) "minimizes ozone-depleting refrigerants".
In most office buildings there will still be scads of freon used as a intermediate heat-exchange medium.
(4) "and reduces the amount of carbon dioxide entering the air." Yeahbut the ability of water to hold CO2 is a strong function of the water temperature... has this been taken into account?
Um, the uplink signal to satellites isnt a good candidate to get picked up by SETI'ing aliens.
It's usually in the 10's to 100's of watts, and directed in a narrow angle to the geosynchronous orbit. And the signal is mighty spread-out over dozens to hundreds of MHz. Not exactly something easy to intercept, or pick out of the background noise.
OTOH your basic radio and TV and radar transmitters are using omni-directional antennas, on much narrower bandwidths, at 100's of times more power, all helping in the reception issue.
Hard to tell from the pictures, but it's unlikely to be a very selective receiver. Which suggests it's going to have a large false-trgger rate from nearly any RF emitter, such as wireless doorbells, wireless thermometers, wireless lightswitches, old flourescent bulbs, police and fire radios, gas meter telemeters, garage door openers, wireless headphones, and even wireless network hot spots. Needs a little work.
Sunlight is 1100 watts per square meter only perpendicular to the Sun. And solar cells are only about 10% efficient. If we assume he's not savvy enough to work up a dual-axis sun-seeking servomechanism, that gives us about 50 watts to work with. That's under a tenth of a horsepower. ONE horsepower can raise 550 pounds one foot per second, so this solar powered car, with frictionless tires, could raise its say 2200 pounds about 0.6 inches per second. If we assume we'd like to climb a 1% slope, the VW then could manage, let's see,.... about 4 inches per second. Waay under 1MPH. Even less if you don't have frictionless tires.
Ok, this Excel thingy must be good for SOMETHING, let's do the math on this huge leeakage problem:
Assumptions: 100 liters spread out in a shell 30 miles thick, 200 miles up, each droplet one microliter:
earth radius 4000 miles
distance up 200 miles
orbit distance 4200
area 221670590.4 sq miles
thickness 30
volume 6650117712 cubic miles
coolant amount 100 liters
microliters 100000000 microliters
microliters/cubic mile 0.015037328
microliters/cubic foot 1.02157E-13
--------------------
So there's less than a millionth of a tenth of a millionth of a microliter per cubic foot up there.
Left for the reader: how many of these droplets will a satellite with say 10sq feet of cross section intersect per year?
BTW if the coolant is a liquid, isnt it likely to evaporate into individual molecules (unless it's soemthing with super low vapor pressure, like mercury) ?
Regards,
Ancient_Hacker
Okay, say it's true, what's the alternative? How many people do you have to grow to replace one PC? How much water does a person use during a lifetime?
It's not enough to point out one cost, you have to compare it to the alternatives?
What a weird way to benchmark a 64-bit CPU-- with 32-bit software, 32-bit OS, and a disk-intensive test.
Perhaps a more releveant test would be to use 64-bit apps ona 64-bit OS, and tests that tend to exercise the element in question, the CPU.
Methinks the test designers were either really, really dumb, or they were aiming to minimize the perceived speed differences between the contenders.... (or they're both).
IIRC the 3M company makes some polonium-powered dust-neutralizing brushes-- something about the beta rays charging the dust particles so they repel each other. Any idea why this couldnt be done to the solar panels?
24GHz is the frequency of the radar signal, which determines the radar's spatial resulution. It's not the data rate, that's an inapt analogy.
BTW it's unlikely an automatic braking system will be easy to design-- The rate of false positives is likely to be much too high. Small objects that are near a half-wavelength in size are likely to give strong reflections. So common road objects like pebbles, lane dots, falling rain, are likely to generate an exceedingly high screech-the-brakes rate.
As many have noted, it's likely to be very unstable. And it's likely to have a very high Vmc, the minimum speed at which it's controllable. That means it's going to have to take off and land at high speeds in order for the control surfaes to have any effect. Not pleasant!
And due to the law of scale, with it's volume (which controls the fuel load) going down as the CUBE but its surface area(which determines the drag) going down as the square, it's going to have way huge drag compared to fuel capacity, so it won't be able to fly for very long before sputtering out of gas. And with a high Vmc it's unlikly to be able to land with out the engine running. Not a very safe device to fly! Better have a parachute on. Which is unlikely to deploy fast enough below a few hundred feet, so anytime you're below 500 feet or so, your life depends on the engine keeping runing.... Hmmmm, no thanks, I'm not going to fly it!
Slashdot Mirror
Is it asking too much that SlashDot do a teeensy bit of math before endorsing this idea? Let's do some rough math: 15% of 115,000 is close to $17K. Assume a 5% mortgage, that's $862 more you have to pay during the first year. For that much, you could buy about 100 Megawatt-hrs of power. The solar system apparently generates "up to 3.5KW" of power, let's say optimistically that's 1KW average, assuming things happen there like clouds, night, angled sun, DC/AC conversion inefficiencies. That's 8.7 megawatt hrs. The solar power costs about TWELVE TIMES AS MUCH as utility power. Assuming you don't use all of that kilowatt (hard to believe, that's less than it takes to run a moderate sized AC), and you sell the "excess" to the power company, and they pay you their cost of generation, you're getting back LESS THAN A TWENTIETH OF WHAT THE POWER COSTS YOU TO GENERATE. And oh, if there were a LOT of these solar-powered houses, we'd have to build MORE GAS-BURNING peak-load generating plants, to handle the load the solar cells shrug off during cloudy weather, nighttime, storms... Holy bleepin deity, can't anybody do a little math anymore?
Er, um, you're about 20% correct. Chemical explosions top out around 10,000 degrees, barely 1/1000th the temp required. They don't use "numerous" fission explosions, one will do, you just reflect the radiation around so it's coming from all sides. The neutron bomb didnt use chemical explosives, just a regular fission bomb with the parameters juggled for maximum radiation and minimum blast. Even so there was still about 30% blast effects. Pu is totally worthless nowdays, the US has about 18 tons of excess Pu that it would like to get rid of, the Russians likewise.. We may have to build several billion dollar reactors just to burn up the excess Pu.
This is all fine and good if you can string a short unbroken fiber cable from endpoint to endpoint, one with very little attenuation so there's a good chance each little photon will get thru to the other end. The catch is the photon has to go from one end to the other while making NO impact on the Universe. The first time it makes a nudge in the time-space continum, it loses its magical quantum state. That makes it really hard to say, route messages, as the act of inspecting the message is going to ruin its quantum goodness.
IANAL, but: "whose principle content is music." Is that a homopo, or did the original agreement really use that word? In which case the agreement may be meaningless...
Any on ANY?? I think I still have a CDC Cyber 172 system dump tape under the raised floor.... So if they're right I can run NOS 1.3 and PLATO on an old Apple ][ ?
We had a small house fire which deposited tons of oily soot everywhere. Sort of like having 10,000 people smoke in your house for a year. The semi-professional house-restoration folks scrubbed the walls with various liquids, which got most of the gunk off, then they brought in these high-falootin ozone generator boxes. A few hours of ozone and the smells were all gone. *But* anything made of rubber fell apart, and *all* the ball point pens dried up. Oil in door hinges siezed up. Assuming there's rubber or similar parts in the computers, and oil in various fan and disk bearings, I would NOT recommend this very effective treatment.
Let's not go overboard here folks: * If this is like most school districts, there's very little informed planning. The computers are unlikely to be well-suited to the environment or to the new power source. Ideally the computers would have been chosen for low power consumption, with laptop-like design. Probably didnt happen, they're probably standard approx 200-watt Ac powered designs. * Solar power is unlikely to be the best way to go. 200 watts of solar power is going to cost THOUSANDS of $, and may only last a few years in challenging environments. A little cow-methane powered generator might be MUCH cheaper and completely locally sustainable (no shortage of cow dung and small motorcycle engines.)
So MicroSoft is going to index files for us? Let's look at their record: * A Start menu thingy "find" that is slow, mostly broken, and doesnt have the smarts to not search .DLL and .EXE files or their own DllPrefetch or Cookie or system32 directories when I'm looking for plain text.
* A background file indexing thingie that seems to take forever.
From these brain-dead search folks you're expecting something GOOD?
*
I tried to simulate the universe on my Apple II. The simulation was amazingly accurate. Too bad it ran in roughly real time...
I see it now, IBM buys SCO, so now they're suing themselves. They "settle" for, say $1B, which they pay to themselves AND deduct it too. Brilliant scheme!
IMHO the name "Atlas" has been kept going as a marketing ploy. The current "Atlas" is as much an "Atlas" as twisted pair Ethernet is the original "garden hose coax" Ethernet. The Atlas has been re-giggered over the years until the only part in common is the concept of using very flimsy pressurized tanks as structural elements. Everything else, engines, boosters, upper stages have all been radically changed several times over. And the reason the success rate was mentioned may be to counteract the Atlas's poor early reliability... Something like 30 big kabooms in the first 35 launches.
You'd think an article in a pub titled "New Scientist" would have at least ONE relevant number, such as the magnet strength, remanence, permittivity, maybe even a B-H curve? But Noooo.....
Seriously, only the BEST magnetic materials are suitable for hard disk surfaces, and there's not even a hint that this organic stuff has ANY of the required specs.
Looks great in a demo, but lots of hard to overcome obstacles, real show-stoppers: (1) COST-- How many people will pay an extra $X,000 to fix what's a non-problem for many drivers? Is this enough volume to bring the cost down to reasonable levels? (2) Reliability-- Any system that involves that many amps is going to have a certain failure rate in the driver electronics. It's possible the legal liabilities may make the system untenable. (3) We're talking major watts of heat dissipation here. The actuators may be able to handle the occasional swerve or bump, but can they handle 60 minutes of washboard road? Not likely without an active liquid cooling loop. (4) False alarms. If this is like most systems of this kind they have ultrasonic or laser sensors to look at upcoming bumps. Works fine on a clean dry road. But add water, snow, blowing dust, or blowing plastic bags, and the sensor is likely to "see" a big obstacle and command an abrupt "wheel up" command. Very nasty induced bump! (5) Lack of driver feedback. If the system hides road conditions from the driver, they may easily end up going waaay too fast for road conditions. Everything will be fine until the system gets to 100%, then all heck might break loose as the wheels lose traction. Airplanes have to be specifically designed by law to give plenty of warning before getting into dangerous parts of the performance envelope. It's time this requirement apply to autos also. (6) Noise. Notice the movies are silent! How much noise do the actuators make, and is this noise less irritating than a little body lean? This may be a technology that's always really neat looking from afar, but not worth it once all the drawbacks are considered.
As the great EE and philosopher Bob PEase has said: "Only problem with a solar-powered night-light is the 12,500 mile extension cord"
Havent we had objects in orbit for 40+ yrs now, many positioned in just the right orbits to transit thru the moon's shadow? Satellites like the GPS series, whose positions are known and tracked to the centimeter?
Why hasnt this effect, if it exists, been noticed 1000's of times?
Guess I'm a quibbler, but: (1) Cold water has been used for decades for cooling. The first major mall in the USA, Southdale, in Mpls, has been cooled by cold well water for oh, a bit over half a century. (2)" 8,000 homes - the equivalent of 32 million square feet". I don't know about Ontario, but around here the average home is under 2,000 sq feet, not 4,000. And piping cold water around to every house is unlikely to be cost-effective. (3) "minimizes ozone-depleting refrigerants". In most office buildings there will still be scads of freon used as a intermediate heat-exchange medium. (4) "and reduces the amount of carbon dioxide entering the air." Yeahbut the ability of water to hold CO2 is a strong function of the water temperature... has this been taken into account?
Um, the uplink signal to satellites isnt a good candidate to get picked up by SETI'ing aliens. It's usually in the 10's to 100's of watts, and directed in a narrow angle to the geosynchronous orbit. And the signal is mighty spread-out over dozens to hundreds of MHz. Not exactly something easy to intercept, or pick out of the background noise. OTOH your basic radio and TV and radar transmitters are using omni-directional antennas, on much narrower bandwidths, at 100's of times more power, all helping in the reception issue.
Hard to tell from the pictures, but it's unlikely to be a very selective receiver. Which suggests it's going to have a large false-trgger rate from nearly any RF emitter, such as wireless doorbells, wireless thermometers, wireless lightswitches, old flourescent bulbs, police and fire radios, gas meter telemeters, garage door openers, wireless headphones, and even wireless network hot spots. Needs a little work.
Your doubts are quite valid.
Sunlight is 1100 watts per square meter only perpendicular to the Sun. And solar cells are only about 10% efficient. If we assume he's not savvy enough to work up a dual-axis sun-seeking servomechanism, that gives us about 50 watts to work with. That's under a tenth of a horsepower. ONE horsepower can raise 550 pounds one foot per second, so this solar powered car, with frictionless tires, could raise its say 2200 pounds about 0.6 inches per second. If we assume we'd like to climb a 1% slope, the VW then could manage, let's see,.... about 4 inches per second. Waay under 1MPH. Even less if you don't have frictionless tires.
Ok, this Excel thingy must be good for SOMETHING, let's do the math on this huge leeakage problem: Assumptions: 100 liters spread out in a shell 30 miles thick, 200 miles up, each droplet one microliter: earth radius 4000 miles distance up 200 miles orbit distance 4200 area 221670590.4 sq miles thickness 30 volume 6650117712 cubic miles coolant amount 100 liters microliters 100000000 microliters microliters/cubic mile 0.015037328 microliters/cubic foot 1.02157E-13 -------------------- So there's less than a millionth of a tenth of a millionth of a microliter per cubic foot up there. Left for the reader: how many of these droplets will a satellite with say 10sq feet of cross section intersect per year? BTW if the coolant is a liquid, isnt it likely to evaporate into individual molecules (unless it's soemthing with super low vapor pressure, like mercury) ? Regards, Ancient_Hacker
Okay, say it's true, what's the alternative? How many people do you have to grow to replace one PC? How much water does a person use during a lifetime? It's not enough to point out one cost, you have to compare it to the alternatives?
What a weird way to benchmark a 64-bit CPU-- with 32-bit software, 32-bit OS, and a disk-intensive test. Perhaps a more releveant test would be to use 64-bit apps ona 64-bit OS, and tests that tend to exercise the element in question, the CPU. Methinks the test designers were either really, really dumb, or they were aiming to minimize the perceived speed differences between the contenders.... (or they're both).
IIRC the 3M company makes some polonium-powered dust-neutralizing brushes-- something about the beta rays charging the dust particles so they repel each other. Any idea why this couldnt be done to the solar panels?
24GHz is the frequency of the radar signal, which determines the radar's spatial resulution. It's not the data rate, that's an inapt analogy. BTW it's unlikely an automatic braking system will be easy to design-- The rate of false positives is likely to be much too high. Small objects that are near a half-wavelength in size are likely to give strong reflections. So common road objects like pebbles, lane dots, falling rain, are likely to generate an exceedingly high screech-the-brakes rate.
As many have noted, it's likely to be very unstable. And it's likely to have a very high Vmc, the minimum speed at which it's controllable. That means it's going to have to take off and land at high speeds in order for the control surfaes to have any effect. Not pleasant! And due to the law of scale, with it's volume (which controls the fuel load) going down as the CUBE but its surface area(which determines the drag) going down as the square, it's going to have way huge drag compared to fuel capacity, so it won't be able to fly for very long before sputtering out of gas. And with a high Vmc it's unlikly to be able to land with out the engine running. Not a very safe device to fly! Better have a parachute on. Which is unlikely to deploy fast enough below a few hundred feet, so anytime you're below 500 feet or so, your life depends on the engine keeping runing.... Hmmmm, no thanks, I'm not going to fly it!