It matters not one whit how many studies show result X. What matters is what is shown by peer-reviewed studies done under controlled circumstances and having a significant sample size.
For example 100 studies done shoddily using sample sizes of 3, 4, and 6 subjects do not outweigh one ten-year study across 1,000 subjects.
Now just on general principles, if one watt of radio energy was harmful, you'd think that people like RF welders, tower steeplejacks, plasma researchers, and radar disk repairers wolsd be covered in suppurating pustules. But they're not. Even people whose heads are hit by 100 watts of much stronger photons (sunbathers, cowboys), they do just fine.
So I suggest you use GQ to check up on the latest fashions, maybe not so much on the best science.
I don't see how this has any relation to driving on actual roads. This is a marked-off course with no cross streets, pedestrians, bicycles, or other vehicles. Even under these very special conditions there's no guarantee it won't drive into the wall or off into thin air. Or hit a mule deer. Or get stuck in a mud-puddle/culvert.
It's going to be interesting to see how the car detects and handles the drainage culverts. The last few miles have corrugated metal drainage culverts crossing the road periodically to carry off the snowmelt. These often get overloaded and instead you have a big mud puddle with a hard metal culvert under the mud. Humans can use a little intelligence and slow down for these. It will be interesting to see how the automated Audi handles these and other unexpected situations!
Er, but there's a very good reason Germanium is not used much as a semiconductor.
It has very high leakage at room temp, and the leakage goes up exponentially from there. By the time you get up to 50C it's basically a poor resistor instead of a semiconductor.
So this really is a "room temperature laser", in the sense that you have to cool it to room temperature.
Below the 1-mm limit, efficiency suffers to such a degree that solid-state thermoelectric devices would become a better choice for a particular application. "
So this device is rated NFG at smaller sizes, by the inventors themselves... and I havent even touched on how friction and surface tension also go down as the square, making moving parts below a certain size just plain useless.
it makes no difference if it's an IC engine or ZC.
The issue is the same. To have a heat engine you need separate regions, one hot and one cold. As the regions get smaller, you lose the ability to keep the hot away from the cold. By the time you're down to 1 centimeter, a large fraction of the heat is lost thru conduction. And it just gets worse from there on down.
And using differential expansion of a solid is a horribly inefficient scheme-- you may have noticed a certain lack of cars powered by the expansion of their tailpipes.
Sometimes I despair about the level of scientific knowledge imparted to today's youth.
There is NO WAY to make a heat engine of any efficiency smaller than a few cc's.
It's the basic SCALING LAW that Galilleo figured out like 600 years ago.
As you make things smaller, their volume, which is their abilitry to burn fuel, goes down as the CUBE of its linear dimension.
But its surface area, which is how it loses heat, only goes down as the square.
So as you shrink things, pretty soon, you can't start a fire. The fire loses heat over its surface area faster than itrs volume can generate it. Which is why you don't see flames smaller than a certain, much larger than micrometer, size.
Even for non-flame sources, the exact same rules apply. So you can't make a heat engine of any usable efficiency below a certain size. Model-airplane engines of 1cc capacity are about the lower practical limit. Anything smaller and you have trouble getting it to light off and even if it does, the heat quickly dissipates.
So just on general principles, one can guess that this touted device has vanishingly small efficiency.
And no, no "but we can INSULATE it" or "the RULES are DIFFERENT down there".
Bah, kids nowdays, so spoiled with the megabit modems.
Before the Bell System modems, there were over-the-airwaves modems, going back to 1930 or so. The endpoints were teletype machines, whirring away furiously at 60WPM, 7.42 bits per character. ( 5 data bits, one start bit, 1.42 stop bits).
The modems wee made up of L/C filters and a trunkful of vacuum tubes. I used to have a military modem, a CVV -something, that was the size of a suitcase and weighed about 60 pounds. 42 BPS. But it could do 42BPS over a noisy fading shortwave radio link, all day long, while taking direct mortar rounds, and never say "NO CARRIER."
>You ever looked at the prices of, say, TV sets, or..... PCs?
I meant at a instant in time, not over time.
When the first LCD TV's came out, were they cheaper than CRT's? Nope. They were priced proportionally to their perceived worth, not in relation to their cost of manufacture.
Same with PC's. Faster CPU's command a premium price.
The price of these things does go down over time, sometimes very quickly.
But the main point remains-- something better is going to be priced higher, independent of the cost of production. Companies are never in the business of leaving money on the table. They make every attempt to Hoover up every penny.
The rockets are well understood. The Atlas/Delta/Centaurs are all 45 year old designs and well shook down and understood. Even the "new" rocket is 85% old Space Shuttle booster, 30 yr old design. The Saturn V was considered well understood and capable of being "man-rated" after six launches. So this rationale does not hold water.
You might look for other motivations, like maybe huge profits for the rocket makers and launchers?
I'm awfully tired of these articles predicting something will be better, cheaper to make and therefore much cheaper to buy.
Nothing in the history of the world that is better than an existing product has been sold for less.
Things end up being sold at a price very near what they're worth to the end user, which often has no relation to their cost of manufacture. Think of perfume, diamonds, or celebrity-diet plans.
Also for something exposed to the elements that has to last many years, there are so many ways to fail. Temperature cycles, moisture, UV, hail, corrosion-- all of these have to protected against, and the cost of these goes up as you make the cells smaller and more fragile.
It's swell to have better (in some sense) cells, but that's just a small part of the overall picture.
Your analysis is fundamentally off-base. Silicon solar cells are expensive, not because of some global conspiracy, but because they require a lot of silicon square footage. One slice of ingot can make several thousand $100 CPUs, or less than a square foot of solar panel. That's one big reason why solar cells cost so much. It would be worse, but for the fact that solar cells are made from silicon slices that are rejected for making IC's. Just a little off-tolerance on impurity level or resistivity and the slice gets sold at a discount to the solar cell folks. If they had to pay the going rate for good silicon the cells would really be out of sight.
Wonderful, but there are an awful lot of warning signs that this thing is not a world-beater:
* It's not rechargeable. And I don't know of any simple electrochemical process that reverses the oxidation of silicon.
* It requires a Flourine-carrying electrolyte! Lithium is bad enuf, but Fluorine is really bad stuff.
* Usually "air-powered" batteries are limited to very low current, slow discharge applications, such as hearing-aids. So it's very unlikely these could ever work like in a laptop or car, where you need amps, not microamps.
* Any practical and competitive battery would have to have a good power-density and be stable and manufacturable at a reasonable price.
This thingy is just a research device, just good for research. It's not a precursor of anything practical.
It's been known for many, many years that there are serious tradeoffs to be pondered when you shrink transistors (and FETs).
Your basic linear dimension versus surface area versus volume scaling laws are in full play here.
You win at first, as smaller base or gate lengths lead to more speed, and less surface area means less capacitance to charge up.
But below a certain size the rapidly shrinking cross-sectional area reaches its current-carrying capability, while noise and leakage loom large.
Right now the low-level chip designers, with their 10^12 atom transistors are already spending a large part of their time with these issues. The challenges are not going to go away, they just get larger as one attempts to shrink things even more. It's unlikely that these hard challenges can be overcome to span the million-million times distance to a true one-atom transistor.
So don't put any big money on ever having one-atom transistors in any practical device.
We're getting a bit too excited here. If you read TFA you'll realize how limited this thing is. Many of these designs can only work at one frequency, usually microwave, in one direction, over a very small area, in 2D, and with considerable scattering and attenuation.
That's a heck of a long way from a usable cloaking device. The problems of scattering and attenuation are going to be particularly intractable.
It's unlikely that every one of the many shortcomings can each be improved by the needed factor of 100 or so.
Perhaps you should consider the difference between a plane that can briefly just barely get off the ground, under optimal sun and wind conditions, carrying no usable payload, versus a plane that can takeoff safely in average or marginal weather, and stay up and get somewhere say against a mild wind, and climb at more than 100FPM, and not stall with a mild tail or crosswind, or breakup in turbulence, and carry a useful payload, perhaps even be human-rated, and do so economically, year after year.
61 meters wingspan, as an estimate, let's say 6 meters width. That's 360, let's say 400 square meters counting the tail surfaces. At 15% efficiency and no clouds at high noon , that's about 60 kilowatts, say almost 100 horses. But if you subtract for unavoidable factors like non high-noon, clouds, battery chemistry, and night, say 40% x 70% x 75% x 40%, we're down to about TWELVE average horsepower trying to lift 3500 pounds. By comparison, your basic very fragile ultra-light plane that can barely get off the ground has like ten times that power to weight ratio.
This thing is not gonna fly, figuratively or literally.
Whatever happened once in Spain does not change the basic facts.
Sometimes the wind does not blow at all, so you need to keep 100% generating capacity that can be brought on line within 20 minutes.
Now your basic coal plant tends to be large and slow (takes many hours) to warm up. So you need a whopping amount of gas turbine generating plants, which not only cost a lot but are going to be idle a good part of the time, just sitting around just in case the wind stops. And it will.
So you're going to pay up front for the generating capacity, then again paying for expensive and scarce oil and gas when the wind stops. Not an attractive financial proposition.
Think. An engine going around at 3,000 RPM, if the belt is 1mm too long, is going to slip the timing by 3 meters every minute. And that's assuming no slip. Timing belts have teeth. Those belts you see on the outside of the engine are not timing belts, they drive the water pump, alternator, and AC.
If his$500 of Diesel exhaust had $500,000 of fertilizer in it, there would be dozens of companies making "Rudolph"-brand fertilizer using the same method, for like the last 100 years.
Crops need nitrogen, phosphorous, potassium, and a few other trace elements. Almost none of those in Diesel exhaust.
I can't tell if you're being serious or sarcastic:
>The timing belt was manufactured to be a few mm too short. But over the course of several thousand revolutions, those mm add up to a massive error, which causes the pistons to strike metal. Thus the car was a write-off.
A timing belt has TEETH, which make it a precise digital computer, dividing the revolution of the crankshaft by the right integer in order to drive the camshaft.
The exact length of the belt is irrelevant-- any extra length is taken up by the tension adjuster pulley's position.
Slashdot Mirror
It matters not one whit how many studies show result X. What matters is what is shown by peer-reviewed studies done under controlled circumstances and having a significant sample size.
For example 100 studies done shoddily using sample sizes of 3, 4, and 6 subjects do not outweigh one ten-year study across 1,000 subjects.
Now just on general principles, if one watt of radio energy was harmful, you'd think that people like RF welders, tower steeplejacks, plasma researchers, and radar disk repairers wolsd be covered in suppurating pustules. But they're not. Even people whose heads are hit by 100 watts of much stronger photons (sunbathers, cowboys), they do just fine.
So I suggest you use GQ to check up on the latest fashions, maybe not so much on the best science.
I don't see how this has any relation to driving on actual roads. This is a marked-off course with no cross streets, pedestrians, bicycles, or other vehicles. Even under these very special conditions there's no guarantee it won't drive into the wall or off into thin air. Or hit a mule deer. Or get stuck in a mud-puddle/culvert.
I have a serious problem with trying to even imagine how you validate the world's best clock.
Would you not have to have a better clock to compare it with?
And how do you know THAT clock is keeping good time?
And who guarantees that the aluminum ion will always vibrate to that precision?
Sounds a bit like the old 3-card monte game.
It's going to be interesting to see how the car detects and handles the drainage culverts. The last few miles have corrugated metal drainage culverts crossing the road periodically to carry off the snowmelt. These often get overloaded and instead you have a big mud puddle with a hard metal culvert under the mud. Humans can use a little intelligence and slow down for these. It will be interesting to see how the automated Audi handles these and other unexpected situations!
Er, but there's a very good reason Germanium is not used much as a semiconductor.
It has very high leakage at room temp, and the leakage goes up exponentially from there.
By the time you get up to 50C it's basically a poor resistor instead of a semiconductor.
So this really is a "room temperature laser", in the sense that you have to cool it to room temperature.
>Please read the summary *again*.
yes, you read it again too, especially this part:
Below the 1-mm limit, efficiency suffers to such a degree that solid-state thermoelectric devices would become a better choice for a particular application. "
So this device is rated NFG at smaller sizes, by the inventors themselves. .. and I havent even touched on how friction and surface tension also go down as the square, making moving parts below a certain size just plain useless.
it makes no difference if it's an IC engine or ZC.
The issue is the same. To have a heat engine you need separate regions, one hot and one cold. As the regions get smaller, you lose the ability to keep the hot away from the cold. By the time you're down to 1 centimeter, a large fraction of the heat is lost thru conduction. And it just gets worse from there on down.
And using differential expansion of a solid is a horribly inefficient scheme-- you may have noticed a certain lack of cars powered by the expansion of their tailpipes.
Sometimes I despair about the level of scientific knowledge imparted to today's youth.
There is NO WAY to make a heat engine of any efficiency smaller than a few cc's.
It's the basic SCALING LAW that Galilleo figured out like 600 years ago.
As you make things smaller, their volume, which is their abilitry to burn fuel, goes down as the CUBE of its linear dimension.
But its surface area, which is how it loses heat, only goes down as the square.
So as you shrink things, pretty soon, you can't start a fire. The fire loses heat over its surface area faster than itrs volume can generate it.
Which is why you don't see flames smaller than a certain, much larger than micrometer, size.
Even for non-flame sources, the exact same rules apply. So you can't make a heat engine of any usable efficiency below a certain size. Model-airplane engines of 1cc capacity are about the lower practical limit. Anything smaller and you have trouble getting it to light off and even if it does, the heat quickly dissipates.
So just on general principles, one can guess that this touted device has vanishingly small efficiency.
And no, no "but we can INSULATE it" or "the RULES are DIFFERENT down there".
Bah, kids nowdays, so spoiled with the megabit modems.
Before the Bell System modems, there were over-the-airwaves modems, going back to 1930 or so. The endpoints were teletype machines, whirring away furiously at 60WPM, 7.42 bits per character. ( 5 data bits, one start bit, 1.42 stop bits).
The modems wee made up of L/C filters and a trunkful of vacuum tubes. I used to have a military modem, a CVV -something, that was the size of a suitcase and weighed about 60 pounds. 42 BPS.
But it could do 42BPS over a noisy fading shortwave radio link, all day long, while taking direct mortar rounds, and never say "NO CARRIER."
>You ever looked at the prices of, say, TV sets, or..... PCs?
I meant at a instant in time, not over time.
When the first LCD TV's came out, were they cheaper than CRT's? Nope. They were priced proportionally to their perceived worth, not in relation to their cost of manufacture.
Same with PC's. Faster CPU's command a premium price.
The price of these things does go down over time, sometimes very quickly.
But the main point remains-- something better is going to be priced higher, independent of the cost of production. Companies are never in the business of leaving money on the table. They make every attempt to Hoover up every penny.
The rockets are well understood. The Atlas/Delta/Centaurs are all 45 year old designs and well shook down and understood. Even the "new" rocket is 85% old Space Shuttle booster, 30 yr old design.
The Saturn V was considered well understood and capable of being "man-rated" after six launches. So this rationale does not hold water.
You might look for other motivations, like maybe huge profits for the rocket makers and launchers?
I'm awfully tired of these articles predicting something will be better, cheaper to make and therefore much cheaper to buy.
Nothing in the history of the world that is better than an existing product has been sold for less.
Things end up being sold at a price very near what they're worth to the end user, which often has no relation to their cost of manufacture. Think of perfume, diamonds, or celebrity-diet plans.
Also for something exposed to the elements that has to last many years, there are so many ways to fail. Temperature cycles, moisture, UV, hail, corrosion-- all of these have to protected against,
and the cost of these goes up as you make the cells smaller and more fragile.
It's swell to have better (in some sense) cells, but that's just a small part of the overall picture.
Your analysis is fundamentally off-base. Silicon solar cells are expensive, not because of some global conspiracy, but because they require a lot of silicon square footage. One slice of ingot can make several thousand $100 CPUs, or less than a square foot of solar panel. That's one big reason why solar cells cost so much. It would be worse, but for the fact that solar cells are made from silicon slices that are rejected for making IC's. Just a little off-tolerance on impurity level or resistivity and the slice gets sold at a discount to the solar cell folks. If they had to pay the going rate for good silicon the cells would really be out of sight.
Wonderful, but there are an awful lot of warning signs that this thing is not a world-beater:
* It's not rechargeable. And I don't know of any simple electrochemical process that reverses the oxidation of silicon.
* It requires a Flourine-carrying electrolyte! Lithium is bad enuf, but Fluorine is really bad stuff.
* Usually "air-powered" batteries are limited to very low current, slow discharge applications, such as hearing-aids.
So it's very unlikely these could ever work like in a laptop or car, where you need amps, not microamps.
* Any practical and competitive battery would have to have a good power-density and be stable and manufacturable at a reasonable price.
This thingy is just a research device, just good for research. It's not a precursor of anything practical.
It's been known for many, many years that there are serious tradeoffs to be pondered when you shrink transistors (and FETs).
Your basic linear dimension versus surface area versus volume scaling laws are in full play here.
You win at first, as smaller base or gate lengths lead to more speed, and less surface area means less capacitance to charge up.
But below a certain size the rapidly shrinking cross-sectional area reaches its current-carrying capability, while noise and leakage loom large.
Right now the low-level chip designers, with their 10^12 atom transistors are already spending a large part of their time with these issues. The challenges are not going to go away, they just get larger as one attempts to shrink things even more. It's unlikely that these hard challenges can be overcome to span the million-million times distance to a true one-atom transistor.
So don't put any big money on ever having one-atom transistors in any practical device.
We're getting a bit too excited here. If you read TFA you'll realize how limited this thing is. Many of these designs can only work at one frequency, usually microwave, in one direction, over a very small area, in 2D, and with considerable scattering and attenuation.
That's a heck of a long way from a usable cloaking device. The problems of scattering and attenuation are going to be particularly intractable.
It's unlikely that every one of the many shortcomings can each be improved by the needed factor of 100 or so.
Perhaps you should consider the difference between a plane that can briefly just barely get off the ground, under optimal sun and wind conditions, carrying no usable payload, versus a plane that can takeoff safely in average or marginal weather, and stay up and get somewhere say against a mild wind, and climb at more than 100FPM, and not stall with a mild tail or crosswind, or breakup in turbulence, and carry a useful payload, perhaps even be human-rated, and do so economically, year after year.
L/D has nothing to do with it.
Do the math-- 3500 pounds and 12 horsepower -- what's going to be the absolute best rate of climb possible with no friction---? under 100 FPM.
Add a little unavoidable drag and you have a really miserable flying machine.
Also if it takes off at 20MPH, then that implies it can't take off if the wind is more than 6MPH or so in any direction.
A miserable and very dangerous flying machine.
Let's do the math.
61 meters wingspan, as an estimate, let's say 6 meters width. That's 360, let's say 400 square meters counting the tail surfaces.
At 15% efficiency and no clouds at high noon , that's about 60 kilowatts, say almost 100 horses. But if you subtract for unavoidable factors
like non high-noon, clouds, battery chemistry, and night, say 40% x 70% x 75% x 40%, we're down to about TWELVE average horsepower trying to lift 3500 pounds.
By comparison, your basic very fragile ultra-light plane that can barely get off the ground has like ten times that power to weight ratio.
This thing is not gonna fly, figuratively or literally.
Whatever happened once in Spain does not change the basic facts.
Sometimes the wind does not blow at all, so you need to keep 100% generating capacity that can be brought on line within 20 minutes.
Now your basic coal plant tends to be large and slow (takes many hours) to warm up. So you need a whopping amount of gas turbine generating plants,
which not only cost a lot but are going to be idle a good part of the time, just sitting around just in case the wind stops. And it will.
So you're going to pay up front for the generating capacity, then again paying for expensive and scarce oil and gas when the wind stops.
Not an attractive financial proposition.
Could it be the other way around, that cosmic rays trigger lightning? So the timing is just a coincidence?
Think. An engine going around at 3,000 RPM, if the belt is 1mm too long, is going to slip the timing by 3 meters every minute. And that's assuming no slip.
Timing belts have teeth. Those belts you see on the outside of the engine are not timing belts, they drive the water pump, alternator, and AC.
Totally ridiculous.
If his$500 of Diesel exhaust had $500,000 of fertilizer in it, there would be dozens of companies making "Rudolph"-brand fertilizer using the same method, for like the last 100 years.
Crops need nitrogen, phosphorous, potassium, and a few other trace elements. Almost none of those in Diesel exhaust.
. They don't get carbon from the ground.
I can't tell if you're being serious or sarcastic:
>The timing belt was manufactured to be a few mm too short. But over the course of several thousand revolutions, those mm add up to a massive error, which causes the pistons to strike metal. Thus the car was a write-off.
A timing belt has TEETH, which make it a precise digital computer, dividing the revolution of the crankshaft by the right integer in order to drive the camshaft.
The exact length of the belt is irrelevant-- any extra length is taken up by the tension adjuster pulley's position.
Nothing to do with floating-point ops at all.
What a bunch of crapola.
Finding and fixing bugs, as any programmer knows, is anything but a simple and mechanical procedure.
About all ClearView can do is go "Oh, the stack has been bashed, let's NOP out the call to this code"
Compare this to the amount of work to find and fix an off-by-one error or an unset pointer.
There is no comparison.