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Comment Re:39% without secondary false-positives. (Score 1) 235

Part of the problem is one of incentives: the incentives to do a study which simply replicates a pre-existing study is low, and many journals won't even publish them.

Yeah that's what I noticed too (my minor was in cognitive psychology - like trying to figure out AI from the opposite direction). When Fleischmann and Pons posted their cold fusion paper, every physics lab in every school grabbed it and tried to replicate it, just because of how cool it would be if it actually worked. I never saw the same zeal to replicate interesting results in psychology. In fact you are banned from trying to replicate some of the most notable experiments because of ethical issues. It always felt to me like "this other guy tried it and this is what happened, so it must be true."

Comment Re:Counter measures (Score 1) 115

Chrome plating is only about 70% reflective. A bathroom-variety mirror is only about 75% reflective. The remaining 25%-30% of energy from the laser would be absorbed by the drone as heat. Aluminum coatings used on telescope mirrors can get to about 90% reflectivity, about 98% with good coatings. But that's at a specific wavelength (visual spectrum), and they're very delicate (only about 100 nm thick) and degrade as cruft settles on them. That's why electroplated chrome is more popular for decorative reflectivity - it's much more durable. (Silver actually has better reflectivty, but it quickly tarnishes upon contact with the air. Aluminum does too, but the resulting aluminum oxide is transparent in the visible spectrum and forms an airtight barrier protecting the remaining aluminum.)

So all a mirrored drone would do is increase the amount of time it takes for a laser to shoot it down. If drones did start to go that route, the obvious countermeasure would be to make the laser more powerful. It's a lot easier to make the laser bigger than it is to keep the mirrored surface of a drone pristine.

Unrelated trivia: The best reflective surface is actually a prism, which relies on a phenomenon called total internal reflection - the same property which makes optical fibers work. Their biggest losses are actually at the air-prism interface where the light enters and exits the prism - typically 99.7%-99.8% transmission. They're highly directional though, so (unless someone can come up with an extremely clever design) wouldn't work omnidirectionally.

Comment Re:Wow (Score 1, Insightful) 310

Solyndra was a scam. Their "technology" involved using half-cylinder solar panels (hence the name) laid out on a plane to get around the problem of lower solar production when sunlight hits at oblique angles. Anyone who's reasonably competent at geometry can tell you the problem right there. The effective collecting area is the projection of the surface of your collectors at a right angle to the direction of the incoming sunlight. That is, the planar area the sunlight sees - the cosine of the angle between the incoming sunlight and a normal from the plane of your collecting area. Doesn't matter whether your panels are flat, a cylinder, pyramids, or whatever - only the projection matters.

And since the largest planar area you can cover given a square meter of PV cells is flat, a cylindrical collector is actually less efficient than a flat panel. In fact it's efficiency is a factor of 2/pi (0.6366), since it's just the ratio of semi-circumference (half cylinder) to the diameter (flat). When some of the Solyndra generation data leaked out, they were indeed about 40% less effective at generating power than a flat panel.

Could they have arranged their half-cylinders in something other than a plane? Yes, but non-planar arrangements run into the problem of shadows from one collector covering up another collector at certain times of the day. The net result is worse than a plane. So flat panels are always best. If you want to capture oblique sunlight more effectively, the mathematically best solution is to tilt the panels to follow the sun (shadows from panel to panel will still interfere at extremely oblique angles). Or to raise reflectors at certain times of the day to reflect the sunlight into your static collectors.

Comment Re:Interesting (Score 2) 310

How many GOP Texans were screaming about how solar, wind and other renewables were nothing but communist liberal bullshit and yet.. here we are.

This is classic misunderstanding of Republican ideals. They're not against renewables per se. They're against subsidizing the sale of technologies which can't self-support themselves. If/when the technology is able to compete economically on its own with existing technologies, they are more than happy to use it.

The error is actually in the environmentalists' thinking. They support wind and solar unconditionally regardless of cost. They then assume everyone else thinks like they do. Since the GOP opposed wind and solar in the past, they erroneously assume the GOP must oppose wind and solar unconditionally. (I narrow it down to environmentalists because most of the people on the left are aware of cost constraints.)

In fairness, there is a non-monetary cost associated with pollution which many GOPers leave out. But if you factor that in, then nuclear ends up being the best choice of power source at present. And most environmentalists oppose nuclear so I can't give them credit for correctly factoring in pollution costs.

Comment Re:Why are solar and wind not on the same land? (Score 2) 310

The viability of solar and wind are highly dependent on geography. Just like you wouldn't build a hydroelectric dam in the desert, there are specific areas which are prime for solar and wind. Building solar or wind outside of those locations represents lower energy production for the same cost, so it's preferable to use that money to build elsewhere. The wind farms tend to get built where there's the most wind. The solar farms tend to get built where there's the most sunshine. It's pretty much only the southwestern U.S. where these two overlap (actually, wind is viable in lots of places, solar is pretty much only viable in the desert southwest + Hawaii).

Once their energy production costs drop to where you can plop a wind turbine or a solar panel pretty much anywhere and it'll cost less than buying power from the grid, then you'll see more overlap. Wind is almost there - its cost per kWh is about the same to 50% more than coal in the prime locations. Solar still has a ways to go, costing 2-4x more.

Comment Re:Hey, great! Here's an idea to improve it furthe (Score 1) 177

No, no keyboard please. I've been waiting for a reasonable 13+ inch tablet to replace my 3 foot stack of music books for my piano. I scanned my most-used music scores long ago (or downloaded from imslp.org), and used to use a 12.1" PC tablet a decade ago for this purpose (it had a 1440x1050 screen, vs the 1024x768 or 1366x768 which was common at the time). I'd consider that size the absolute minimum size and resolution - the notes are (barely) large enough to easily recognize at typical reading distance when placed on a piano, and the resolution is high enough to easily distinguish different types of notes from each other. 18" would be just awesome.

I realize this isn't exactly a prevalent use case. But those of you looking for a large laptop already have a lot of choices, and those of you looking for a small tablet already have a lot of choices. Don't ruin this for those of us who want a larger tablet just because you personally don't have a use for it.

Comment Re:I don't think K-12 CS is a good idea anyway (Score 3, Informative) 183

It's actually far, far more instructive to read and think about and critique less good books. By seeing the mistakes those authors make, and how they abuse rules of composition in ways that don't work is far, far more instructive.

Exactly. For a visual analogy, if you see a movie with good visual effects, you come out thinking that looked really good, without really understanding why it looked good. If you see a movie with bad visual effects, you come out and talk with all your friends about how this effect looked so fake because of A, and that effect was bad because of B. Once you understand a bunch of stuff which doesn't work, what's left over is mostly stuff which does work.

One of the greatest benefits of digital photography has been the instantaneous feedback. You see something interesting and take a picture. The picture doesn't look like you imagined it would, so you tweak some settings on your camera and take another picture. You repeat this process noting which changes seemed to improve the picture the most. And eventually (hopefully) you arrive at the picture as you imagined it would look. You have to crawl through all that stuff which doesn't work in order to learn what does work. Being presented only with the final successful picture does very little to teach you how the photographer arrived at that picture.

Comment Re:I don't think K-12 CS is a good idea anyway (Score 2) 183

The poor kid was awfully, terribly confused. Because nothing made any sense. It was all presented as a collection of "facts" and "rules" that you then have to "apply" to problem after problem.

The whole concept of thinking or reasoning or working out is utterly absent (first principles? what's that?). The idea seemed to be to identify the fact to apply (by magic? guessing?) then apply it to reach the answer.

Yeah, that's the big difference I'm noticing from when I went to school and when I'm tutoring my nephews and nieces. When I was in K-12, they taught basic concepts and how you could build and apply them to solve problems and develop more complex concepts.

The kids I'm tutoring now are taught methods. If you have this type of problem, the method you use to solve it is to plug in this number here, that number there, and out pops the answer. No attempt is made to explain why the method works, or why this number has to go here, or why that number has to go there. Our educational system is putting a generation of kids on a career path where they'll only be qualified to push buttons in a specific pattern to solve problems, without understanding what the buttons do nor why that particular pattern of pushing buttons solves the problem. Never mind how to design such a machine with buttons.

From what I gather, the teachers don't have much choice in it too. It's the teaching method sanctioned by the school district, so they're required to teach it that way. It makes me think the people coming up with these teaching methods don't really understand the topic in the first place, and are imposing their naive approach to tackling something they don't understand onto all the kids. It seriously makes me consider home-schooling my kids or finding a decent private school.

Comment Re:On Its Way Out (Score 4, Insightful) 220

Jobs didn't want Flash on iOS because it tore down the wall of their garden. In the iOS ecosystem, the only way to install an app is via the App Store, where Apple gets a 30% cut. If they had allowed flash, anyone could write a flash app, put it on any web site, and you could browse to that site and run that flash app on your iDevice without paying Apple their 30%. Apple also disallows compilers and tightly controls emulators for the same reason.

All that talk about flash draining battery life was just spin to put lipstick on this pig-headed decision. Flash on Android didn't run by default - any flash scripts on a web page were replaced by a stylized F. If you tapped on the F, only then would that flash script run. If you've used Flashblock on Firefox, exact same thing. So no excess battery drain from ads or whatnot unless you specifically allowed the flash app to run.

Flash was originally created as an artist's animation tool. It was never intended to be the web's de facto executable scripting language. That's why it has so many security holes - because it was being used in ways it was never originally intended. Now that HTML5 adds many features which previously could only be accomplished via flash, and more importantly are designed from the get-go for web use, it is natural that flash is being phased out. Jobs had nothing to do with it, and certainly his decision a decade ago when HTML5 wasn't around still makes no sense (until you recognize the financial reason).

Comment Re:Good riddance to bad rubbish. (Score 2) 220

Flash originally was an artist's tool for creating animations with a minimum of fuss, and more importantly for the web a minimum of bandwidth. It was born when someone asked, if I'm making an animation of a character walking in front of a static background, why does it need to be encoded as a single video? Why can't I just code (transmit) the background once, then overlay the moving character on top of it?

Its flexible nature allowed it to be hijacked by sites wishing to display video, because the folks in charge of the HTML sat on their collective asses when there was clearly a demand for more flexible scripting features to be added to the HTML standard. Once a critical mass of people had installed it to view movies, advertisers began to use it to create those annoying animated ads.

Flash never asked to be the de facto executable scripting language for the web (though I'm sure Macromedia/Adobe weren't displeased with that development). That's why it has so many security holes. For its original intended purpose as an artist's tool, it is not rubbish, and is arguably the best tool out there. And even if it's excised from web browsers it will continue to be used to create movies and TV shows.

Comment Re:Poor comparison (Score 1) 345

The Boeing 747 has its instantly recognised "hump" precisely because Boeing thought at the time of its design that it wouldn't have a long sales life as a passenger aircraft, as the future was "obviously" supersonic for passenger transport. Therefore, the design was optimised for roll-on roll-off cargo transport through the nose section, which made it a very good cargo aircraft and thus increased its forecasted sales life

It's worth noting that Boeing has tried pitching a fully double-deck passenger 747 to the airlines every few years almost since the 747 first rolled out. There has never been enough demand for it so Boeing never built it. The A380 (still hasn't turned a profit) seems to bear out that market research.

The 747 was actually Pan Am's baby - the president of Pan Am personally asked Boeing for such a large aircraft. Boeing wasn't so sure about its viability in the market, so you're right they hedged their bets.

Comment Re:Upstart? Scarebus? Comparison to Concorde? (Score 1) 345

Regardless of what regulatory conspiracies may or may not have contributed, Concorde was ultimately doomed by the Arab oil embargo in the 1970s which caused oil prices to quadruple. Any claims that it was financially viable are a fantasy. By the time it retired it was barely eeking out money in what is probably the most profitable route in the world (London/Paris - New York/DC), meaning it would've lost money pretty much everywhere else.

GP has it a bit wrong - people weren't sure if supersonic transport or large efficient planes were the future back when oil was cheap in the 1960s. Once oil prices shot up, it was obvious which was better.

"More software projects have gone awry for lack of calendar time than for all other causes combined." -- Fred Brooks, Jr., _The Mythical Man Month_

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