From the "any publicity..." file

23 August 2010 — dan

Imagine my delight at receiving the following:

From: "Clink Admin" >admin@clink.com.au<
To: dan@dansdata.com
Subject: A review?
Date: Sat, 21 Aug 2010 15:21:37 +1000

Hi Dan,

I was wondering if you would do a review of something on my website, address in signature.
Not sure if anything on there is along the lines of stuff you would normally but think there may be a couple of items that fit in.

Would love if you would do a review of my Vortex Analogue Interconnects, these have proven very popular cable.
http://clink.com.au/audio/stereo.htm (bottom of the page)
So would be great to get an independent and unbiased view of these.
Would only ask you to do a cable review though if you feel it is something that has an impact on audio quality.
If your of the school of thought that they have no impact then prefer not to have a review done as it would be very short, probably in the under 10 words variety of short.

Gregory
Cinema Link, Sales
675 Elizabeth St
Waterloo NSW 2017
Ph: (02) 9698 4959
www.clink.com.au

[There was a bit more to this e-mail; I've corresponded with Gregory previously. He asked if I'd like to check out one of his HDMI switches, which I don't actually have the equipment to test but which seem quite handy; by linking to them and other pages of his without so much as a nofollow, I hereby repay Greg for what's going to happen to him in the rest of this post!]

My answer:

Yeeeahhh... you haven't read much of my site, have you :-)?

(Or this blog, for that matter.)

It's the "school of thought" part that I think is the problem. There's no need to separate people into pseudo-religious "schools of thought" over a question that can be settled by scientific means.

We know, with the same certainty that we know that the GPS system and personal computers work and for many of the same reasons, that none of the conventionally-measurable electrical characteristics of analogue cables have any effect on the sound. Well, except in particularly pathological cases where some truly bizarre cable architecture adds substantial reactance or something, in which case it only makes a system sound better if there was something wrong with the system in the first place. Like, your speakers have 14 drivers wired in parallel and thus have far too little impedance for your amp to happily drive, so hooking them up via carbon spark-plug leads or something that add a lot of resistance un-ruins the sound.

(See also those occasional fringe-audiophile products that are actually quantifiably bad, like this amplifier, plus a veritable cavalcade of dreadful valve amplifiers. All of which have users who insist that they sound GREAT.)

[Oh - in case you're wondering, yes, Cinema Link have fancy digital cables, too...]

The analogue-cables-sound-different response to the electrical-engineering argument is to say that DC-to-daylight frequency and phase analysis just doesn't measure some special something that they know when they hear it, science doesn't know everything, et cetera.

But a vanishingly small percentage of the people who say this ever bother to do even a simple single-blind test to see if they, themselves, can actually hear any difference between their special cables and lamp cord. Such tests really are not difficult to do at all - all you need is a trustworthy friend to flip coins, swap cables and make notes, some very elementary experimental design, and a spare afternoon - but they're amazingly unpopular. Un-blinded tests remain immensely popular, but it's trivially demonstrable that those don't work.

This is my favourite recent example, but there are countless others, covering the entire breadth of live and recorded sound. Vision and hearing are subject to an immense amount of processing by the brain before consciousness gets to perceive them.

(Another favourite of mine: Famous concert violinists are often certain that they can tell the difference between a priceless antique violin - especially if it's their Stradivarius or whatever - and a high-quality modern instrument. But when you do a blinded test, the results, once again, drop to chance levels! They can probably pick the Strad blindfolded if they're actually holding it in their hands, but that's all.)

Some audiophiles go so far as to say that no matter how perfect the experiment design, with no possibly-sound-colouring ABX switchboxes or skull-resonance-changing blindfolds involved, these sorts of differences just can't be detected by science, in the same way that God will never permit Himself to be detected by scientific investigation. Exactly how these people figured out that the new cables sounded better is, in these cases, something of a mystery.

(The people who insist that cables need "burn-in time" have a particularly neat way out of blinded tests; they can just assert that the... phlogiston, or whatever... leaks out of burned-in cables when you disconnect them. But I'd be willing to bet quite a lot of money that swapping out their expensive burned-in wires for hidden $2 interconnects and bell-wire speaker cables would pass entirely unnoticed.)

I'm inclined to go easy on people who buy fancy cables and reckon they sound good. We all fool ourselves frequently, which is why science is so important, but a fooling of oneself that leads to essentially harmless happiness is not a major crime.

But I really must insist that people who're in the business of making and selling fancy cables have no right to make any claims about the "sound" of their products, if they haven't at least hired a few first-year electrical-engineering students to spend a day doing an independent test.

If, when blinded tests were done, they at least reasonably frequently showed that fancy cables sounded better, then it'd be no big deal to sell such products without doing the tests yourself. But what we instead keep seeing is that in a blinded test people can't tell the difference between Monster Cables and (literal) coat-hanger wire. (Monster products may be overpriced and often sold in a blatantly dishonest way, but surely they ought to beat coat-hangers!)

Given this, I cannot help but consider the basic rationale for products such as your cables as being as unproven as the notion that a chiropractor can cure diabetes, or that all poor people are poor because they do not adequately desire wealth.

It's not the Middle Ages any more. We know where lightning comes from, we have machines that routinely fly hundreds of people thousands of miles in (relative) comfort, and our doctors have figured out that it's a good idea to wash your hands before operating. Every day, people in First World nations are surrounded by proof of the effectiveness of scientific inquiry that's so bright, loud and ubiquitous that we, apparently, have developed the ability to tune it out when it suits us. But that doesn't make it a good idea to do so.

You're not a quack, and I don't think you're a scam artist, either. Your cables aren't outrageously expensive relative to the price of the components and assembly - they might as well be free, when compared with the truly out-there cable vendors. And you don't sell $1000 power cables, either (...do you? Tell me you don't!). But this doesn't mean that sending samples of new cables to your existing customers and using their testimonials in advertising is an acceptable way of proving your claims.

If testimonials were a good way of proving the scientifically dubious, I'd be torn between devoting all my time and money to Transcendental Meditation in order to develop the ability to fly and walk through walls, or devoting just as much time and probably even more money to Scientology in order to develop the ability to control space and time.

At the end of the day, I suppose you do end up with "schools of thought", but the members of those schools are not "people who reckon special cables sound better" and "people who don't" (or "people who reckon Uri Geller has paranormal powers" and "people who don't"; I'm sure you can provide many of your own examples). They're "people who believe this question is amenable to rational investigation" and "people who don't care".

You're allowed to not care. Everyone's entitled to his opinion. But nobody's entitled to be taken seriously.

Gregory replied:

Thanks for taking the time to reply in depth, and for the informative links.

I've taken a little more time this time to read some of the pieces on your site and understand a little more of your thoughts on audio cables.

So I'll take that as no, or at least I'll take it as something that would be detrimental to my business health.

To which I replied:

...and you are thus acknowledging that if you made an attempt to figure out if your fancy cables worked, you'd find that they didn't? :-)

[Greg's, regrettably, not yet found time to reply to that.]

As I said, for hi-fi this really doesn't make a whole lot of difference either way. Even the really wacky Shun Mook or Peter Belt (...or just about anything else that 6moons thinks is fantastic...) sort of hi-fi cultism doesn't really hurt anyone - certainly not by the standards of the usual kind of cult. Some nut out there has probably bought speaker wire instead of nutritious food for his children, but that is hardly a probable situation.

That doesn't mean that the same patterns observable in truly harmful things like crazy cults and medical quackery aren't valid when you see them in other contexts, though. One I find particularly common, which is very much on show in the audiophile world, is the peculiar and inexplicable situation in which the better you investigate something - eliminating extra variables, reducing experimenter bias, reducing the ability of subjects to fool themselves - the less effect that something turns out to have.

When "lousy test" shows "huge effect" and "better test" shows "medium effect" and "further-improved test" shows "not much effect at all", it may be that the latter two tests were false negatives.

But it usually does actually mean that "perfect test" would show "zero effect".

Posted in Electricity, Music, Science. 20 Comments »

BANG! Art! BANG! Art!

5 July 2010 — dan

Lichtenberg figure being made

In which Theo Gray makes some acrylic Lichtenberg figures rather bigger than the ones I can afford.

Lichtenberg figure being made

More detail in these excerpts from his book.

(Via.)

Posted in Art, Electricity, Science. 9 Comments »

Irresponsible Mayhem: The Saga Continues

5 May 2010 — dan

This post from 2007 was about a highly entertaining YouTube clip of some people pulling arcs from a long string of nine-volt batteries. With those neat little clip connectors, 9V batteries are just begging to be clipped together into very long, very dangerous daisy-chains. And, in that particular case, they had 125 batteries in series, by my count. That adds up to a nominal 1125 volts DC.

(The 9V terminals are also, of course, clearly intended to make them easy to lick.)

But now, unfortunately, that video's been removed.

So I went hunting for more experiments of this type.

Here's a string of 19 (for 171 volts DC, nominal) running a compact fluorescent lamp:

The experimenter boldly holds the thin-insulation alligator-clip leads in his bare hands, but that's as exciting as this video gets. Interesting to see that these lamps run from DC as happily as from AC, though.

Here's some fun with 52 batteries:

That'd give 468V if the batteries were all at their nominal 9V, and could easily make it to 500V with fresh batteries. But apparently these were discarded "8.4... ish" cells of unknown provenance (my money would be on a company replacing the batteries in all of its smoke detectors). 52 times 8.4 gives a mere 437 volts, open-circuit.

(All of these voltages will plummet when you close the circuit, to start striking arcs, because the more current you ask for the further the terminal voltage will sag, and alkaline nine-volters aren't meant to deliver more than a very little current. Energizer, for instance, don't provide a maximum-current rating on the datasheet [PDF] for their standard alkaline nine-volters, but the maximum current on the load-versus-capacity graph is half an amp, at which discharge rate the capacity drops from a 25mA-load maximum of more than 600 milliamp-hours, to a little more than 300mAh. If you buy a Big Bag of Innocent Unsuspecting 9V Batteries the cheap way, by getting carbon-zinc "super heavy duty" batteries instead of alkalines, the rated current [PDF datasheet] is now only about 5mA, and the highest current on the performance graph is only 25 milliamps. You're not going to be able to pull a multi-amp arc out of a string of those poor little things for long. Ex-smoke-detector alkaline batteries will probably work a lot better for this sort of Unwise Experiment than will brand new carbon-zincs.)

Here we have 48 batteries in series - so, maybe more than 460 volts open circuit - molesting a coin:

(With, again, not as much attention paid to safety as might have been.)

Here, though, is what we've been looking for!

Four hundred and ninety 9V batteries, baby!

They're good for quite a lot of arcing before the chain's weaker links started breaking, too. I hope somebody was at least wearing a couple of pairs of sunglasses simultaneously.

490 times nine volts gives 4410V; fresh batteries would add up to more than 4700V. These are more ex-smoke-detector batteries, though; the video description says they only added up to "almost 4000V".

Even four thousand volts can't strike a very long arc by itself. The dielectric breakdown strength of dry air is about 33 kilovolts per centimetre (around 84 kilovots per inch). So four kilovolts, even with humid air helping it (and hindering electrostatic experiments...), can only strike an arc a few millimetres in length, at the very most.

Once you've struck a spark with the terminals close together, though, you can draw it out into a much longer arc, because the ionised air between the terminals - which may include vaporised matter from the terminals - is much more conductive than un-ionised air. That's how arc welding works (and Jacob's Ladders too, for that matter), and that's what's happening in the video clip.

If I ever do something like this, I think I'll leave the striking of arcs and burning of batteries for the grand finale, and do some low-current high-voltage stuff first.

Posted in Electricity, Hacks. 9 Comments »

Would you believe... superconductors?

6 April 2010 — dan

A reader writes:

Can you do some research on this amazing device, which claims to be a superconductor. Is it for real? If so it is the most advanced scientific device on the market.

Company: KESECO
Device: ULTRA Current Improvement System
This claims not to be Power factor correction, rather it is a superconductor!

It has relevant patents and scientific explanations. I am having a hard time discrediting this, maybe it is for real
Check it out Dan:

www.Keseco.com
www.Enerwise.com.au

Andrew

Keseco do seem to be using some words having to do with superconductivity, don't they?

They go on to talk about "rotating electromagnetic waves" being converted to and from "far infrared", and the "crystal structure" of the wire. This is all far too advanced for little old me.

(I bet it does wonders for air and musicality, though.)

OK, yes, superconductivity would save power, if you replaced all of the transmission wires with superconductors (as is, very occasionally, actually done). But whatever Keseco say they're doing, that isn't it. Their gadget connects in parallel with your existing wiring.

(Even if you could magically turn all of the conductors in your home into superconductors, while simultaneously sprinkling everything with the pixie dust it'd need in order to still work with zero conductor resistance, you'd save only a tiny amount. Where electricity is lost as heat in the home, it's almost all meant to be lost as heat, either directly as in a toaster, or indirectly in the course of causing some motor, CPU or loudspeaker to work.)

Oh, and no superconductor yet discovered operates at a temperature above -138 degrees Celsius.

But I'm sure these minor quibbles are all thoroughly dealt with somewhere in Keseco's complicated explanations.

The Keseco devices may have an unusual theory of operation - whatever it is - but in appearance and installation they're pretty standard magic energy savers. You just connect the Keseco device in parallel with your existing wiring in the breaker box, and that's it. Whatever it does, it does it to any combination of devices inside the building, without necessarily even being in there itself, much less being electrically coupled or configured to them in any readily apparent way.

Never mind that, though; you can't argue with success. And Keseco's devices are very successful. Just ask them!

Don't ask anyone actually in the electrical-device-analysis business, though. As is usually the case with these sorts of devices, Keseco does not appear to be in any hurry to do any independent tests of their power-saving claims. Neither are these Enerwise people here in Australia, as far as I can see. The Enerwise site uses terms like "proven" and "the results are in!", but the actual evidence is just the usual wall of testimonials. (I eagerly await the publication of Enerwise's "Big Book Of Brag"! Surely that will be where we'll find the long-awaited independent controlled tests!)

Keseco-slash-Enerwise have, of course, apparently been on the news. And as we all know, they won't let you say something on TV unless it's true.

But wait - Keseco's "Certificate" section has an actual "Test Report"! It's reproduced so small as to be almost illegible, but I managed to decipher it!

It's a RoHS test, that certifies that the Keseco products pass poisonous-chemicals tests. Not that they work.

And then, also in the Certificate section, there's some more paperwork, but in Korean.

(This also seems to be par for the course in the miracle-energy-product world. If there are tests, they'll often be from labs in far-flung parts of the world where they don't speak English, even though they're being used to support claims made for products that're sold in English-speaking countries. Even energy-saver companies that are based in English-speaking countries sometimes, somehow, manage to do this.)

For the squinting-and-translating-Korean convenience of my readers, here are direct links to the largest images available from the Keseco "Test Report" page:

page 1
page 2
page 3
page 4
page 5
page 6
page 7
page 8
page 9
page 10
page 11
page 12

In among the Hangul there's what that looks like a statement that... something... used two-point-something per cent less power after... something else happened. But I'm not sure.

None of it seems in any way connected to Keseco's "guarantee" of a 5% power saving.

The "Performance Report" on keseco.com makes bolder claims, and is another entirely typical document for this sort of outfit. Bare numbers, no info on how the test was controlled, and further silence on the all-important question of whether the tester was on the Keseco payroll or not.

This sort of proof-by-assertion is standard for makers of energy savers, magical mileage-improving fuel additives, magnetic anti-arthritis bracelets, ultrasonic pest repellers, literally-magic "money magnets" and so on. There are hundreds - heck, probably thousands - of companies of this sort, big and professional enough to put together a sales package like Keseco's. But even when these companies manage to get large amounts of money from canny investors, they never, ever do the proper tests that would let them actually prove their claims and take the giant step up to their rightful place high up the Fortune 500 list. Instead, they sell (or attempt to sell) their products one at a time, direct to consumers whose own standards of evidence are satisfied by the testimonials presented.

(Often, there's a hybrid middle level between the company-that-should-do-some-proper-tests and the gullible consumers. That level is occupied by the gullible distributor, who liked the product so much he bought a franchise, but who has not yet realised that there's no good reason to suppose the product really does work.)

Keseco's PDF catalogue, and their "Products info" page, also cheerfully claim "Preventing Harmful Electromagnetic Waves" as a feature of their system. I suppose that means your microwave stops working, too. If mobile phones, by some freak chance, do turn out to be bad for you, I suppose your Keseco box will also suck up all of their emissions.

The site and catalogue also say the Keseco boxes "prevent" static electricity. Somehow. Somewhere. And then the catalogue has a picture of what looks like a molecular model of DNA, and then something about Fermi energy. I'd have been completely convinced if only they'd worked in Bose-Einstein condensates and particles with imaginary mass.

The Keseco catalogue also has a number of examples of another standard marker for this sort of business, Irrelevant Certifications Offered As If They Have Something To Do With Whether The Product Works.

There's a Korean patent! A registered design! A trademark! A corporate insurance policy of some sort! Alleged CMA, CE, ANCE, ISO 9001 and RoHS conformance! None of which means the product bloody works!

(Just to make this clear one more time, because it comes up so very, very, VERY often: The Patent Offices in various countries make no attempt whatsoever to determine whether an idea presented for patenting is actually good for anything at all. You don't even have to provide a working model. There's usually some basic screening to keep out blatant perpetual-motion devices {possibly with a caveat that you can patent such a device, but only if you do bring a working model!}, but that's all. All the patent office cares about is whether the idea is sufficiently different from other things that already exist to be worthy of a patent - and most patent offices are so overworked these days that they don't even do this very well. So despite what thousands of crackpots and swindlers have claimed over lo, these many, many years, there is no connection whatsoever between patentability and functionality.)

I remind you, gentle reader, that all of the wonderful effects Keseco products are supposed to cause are, somehow, created by a box that you just stick in or near the building's breaker box, and wire in parallel with the building's circuits. Whatever those circuits are, and whatever business you're in. It would be entirely churlish to suggest that this is analogous to making a "water saver" that hangs off a T-fitting next to your water meter, thereby impeding or encouraging the water's flow in no way at all. So I won't do that.

I suggest, Andrew, that you just put up with your present electricity bill for another year. By then, either Keseco will be a household name, one of the most profitable corporations in the world, with Nobel Prizes in the pipeline for their engineers... or they'll still be grubbing around with all the other retail sellers of worthless "power saving" talismans.

But oh, dear - the proudly-displayed accreditations in Keseco's catalogue go all the way back to 2004! The site itself has been around since 2002!

(It used to have an awesome flash intro.)

And yet still, no Keseco boxes in every electrical substation. No Keseco boxes the size of Winnebagos hanging off the side of every aluminium smelter. No Nobel Prizes.

I just can't work it out.

(UPDATE: More on the Keseco box.)

Posted in Electricity, Scams, Science. 8 Comments »

When cat toys are outlawed, only outlaws will have cat toys

3 April 2010 — dan

A reader writes:

I've got a couple of cats, had 'em for a couple of years. I have trouble motivating them to chase their toys, ping pong balls, etc - it works once or twice a week, but otherwise they just ignore it. So I've decided to bring out the big guns and get a laser pointer.

It seems they're much harder to get in Australia since all those airplane shenanigans, even though I hardly need a galactic-range pointer.

Was wondering if you had a suggestions for where to nab a laser pointer appropriate for kitteh?

Jack

It's still pretty easy to buy your basic button-cell keychain laser pointer from electronics stores here in Australia. I think there might have been a brief drought when the new Think Of The Children Or The Pilots Or the Puppies Or Something OMG JUST BE AFRAID EVERYONE law was passed, while the stores made sure that the humble cat toys they were selling yesterday hadn't suddenly been transmuted into illegal death rays.

But basic laser pointers are easy to find now. Here's one at Altronics, here's one at Jaycar (Jaycar have several other options, too).

[There are cheaper pointers on eBay, from sellers who at least say they're in Australia, which means they shouldn't be sending your purchase through Australian Customs to be confiscated by our ever-vigilant protectors. People may still be selling cheap pointers at the markets, too. If you believe price equals quality, on the other hand, note that the writhing transporter-accident creature that absorbed both Dick Smith Electronics and Tandy (Radio Shack) in Australia will be pleased to sell you a keychain pointer for $36.98 - at "DSE" here and at "Tandy" here!]

Altronics and Jaycar both want $AU14.95 for a bloody keychain pointer, which is of course a frankly insulting price. For little more than twice that much at current exchange rates a nice man in China will sell you a whole non-contact infrared thermometer, that incorporates an aiming laser. But which I'm sure will whistle through Australian Customs, just like all of the "laser-guided" circular saws, ultrasonic distance measurers, scissors, et cetera.

I chose not to choose a $15 keychain laser. I chose something else.

Home-made laser pointer

This prison-shiv of a laser pointer...

Home-made laser pointer

...took a lot longer to photograph than it did to make.

It's pleasingly bright at around 25mA current - much brighter than your standard button-cell cheapie, but not bright enough to pose any real eye hazard. It has an egg-like shape that feels good in the right hand, with a nice clicky steel switch-bar under the thumb. It has adjustable focus, so you can widen the light out into a splodge of quantum speckle at will. And it had a total parts cost about the same as the abovementioned stupidly-expensive keychain lasers. You could easily make something similar for less than $10, including the two AA batteries.

(It's quite hard to find laser pointers that take AA batteries, these days. Those little button-cell pointers are churned out by the zillion, and many pen-shaped pointers use a couple of AAAs - but if you want the substantially higher capacity-per-dollar of AA power, I think you may have to assemble your own pointer. Or, at least, hack bigger batteries onto a smaller pointer.)

The key component in a do-it-yourself laser pointer is a laser diode, lens and heat-sink assembly - commonly referred to as a laser "module", or "package".

Well, that's the key component unless your DIY ethic requires you to build the module from scratch, as well.

(The state of the DIY art has not, to my knowledge, yet reached actual home-made laser diodes. It's surprisingly easy to make your own very dim LED, though!)

There's no financial reason to build your own laser module, because you can buy ready-built modules in various shapes and sizes - even in colours other than red - startlingly inexpensively on eBay, or from dealers like DealExtreme. And no, Australian Customs won't confiscate your laser module, either - or, at least, they didn't confiscate any of mine.

Because, like an IR thermometer, a laser module is demonstrably not a laser pointer. And it is laser pointers that are illegal here, don't you know.

(I haven't tried importing a genuinely dangerous high-powered laser module, of the type used in hefty laser "pointers" that were already illegal in Australia before the current ridiculous laws went through. I would make a small wager that you would have no trouble importing such a module at all, though. But don't worry - as we all know, those scary domestic terrorists who we keep being warned about, but who mysteriously never seem to actually commit any acts of terrorism, must be so impotent on account of how they are too dumb to figure out how to connect a multi-watt invisible-beam IR laser module - you know, a laser that's actually dangerous - to a battery.

Ahem.

The question for the non-terroristic cat-toy maker is which of the (very) numerous cheap red laser modules will actually suit your purpose. I am happy to announce that I've done the legwork for you, here, for DealExtreme's range at least. I bought a few of their finest, cheapest red laser modules, and this one, yours for a princely four US dollars and six cents delivered to anywhere in the world, is the one you want.

It's got a nice big sturdy heat-sinking case, it's usefully, though not dangerously, bright from modest power, and it's got the abovementioned adjustable collimating lens, too.

The other components of a DIY laser pointer:

1: Batteries. Two AA alkalines, in this case; feel free to use some other combination if you like. (Three D cells would give you outrageously long run time.)

The batteries you choose determine which...

2: ...resistor you should use in series with the laser module.

Laser diodes, like their older relatives, the LEDs, need some kind of current limiting to prevent them from going into thermal runaway and dying very quickly. Inline resistors are usually the simplest option.

I found that the four-dollar DealExtreme module ran nicely, but not excessively, brightly from two AAs through three 91-ohm resistors in parallel, for an aggregate 30.3 ohms. I couldn't find a roughly-30-ohm resistor for the final assembly, so I used a couple of 16s in series. Small laser diodes draw only tens of milliamps, so little quarter-watt resistors are more than good enough.

If you buy some other laser module, don't just trust the "2-4.5V" or whatever that was listed on the eBay auction, hook it up to two AAs, and kill it. You'll need to put a multimeter in milliamps mode - which, remember, has a little resistance of its own - in series with the module and fiddle with batteries and, initially, larger resistance values, to find a suitable value. (That's how I ended up with three 91s in parallel - I started with one 91-ohm, which gave a very dim beam, then put another one in parallel, et cetera.)

The quick and dirty way to figure this stuff out for a laser module of unknown provenance is by starting with resistor values that're clearly much too high - by themselves, across the power supply, they'll let much less than the module's rated current flow - or by using a bench power supply that lets you limit voltage and current. Then you reduce the resistor value (or gingerly wind up the current knob) until the dot stops getting noticeably brighter. Wind it back a bit from that point and you should have a safe value. Or just stop when the dot's still getting brighter with more current, if it's already bright enough for your purpose.

Or you can, of course, sidestep all of this and just buy that DX module, and run it from two series 1.5-volt cells and about 30 ohms.

3: A battery holder. Little black plastic holders like the one I used are almost free on eBay, or you can bodge something up yourself. (Thumb-tacks make good battery contacts, by the way.)

4: A switch. I used a microswitch I had sitting around, which gives a pleasing tactile feel. Any old switch will do, though. Momentary, like my microswitch, if you want the usual hold-down-the-button kind of laser pointer, or standard "unbiased" if you want a pointer that stays on by itself.

(For about the same almost-free price as a black plastic AA-battery holders, you can get a black plastic AA-battery holder with an unbiased switch built in.)

5: Stuff to hold it all together. Solder and glue, for a more professional result; tape and positive thoughts, for a less professional one.

The weird organic-looking white stuff on my pointer is a couple of blobs of polycaprolactone plastic, about which I must digress, because it's brilliant stuff.

At room temperature, polycaprolactone is a tough white plastic, like nylon. But above about 60°C it becomes a pliable, bouncy, transparent putty-like material.

Polycaprolactone is transparent when it's hot

(This is the laser assembly before the second blob of polycaprolactone had fully cooled. It'd be fun if it stayed like that, but you can't have everything.)

You take polycaprolactone granules, and you put them in boiling water, and they turn clear and stick to each other. Just stirring the growing blob around a bit will pick up any loose pellets. Then you fish the spongy blob out and squeeze the hot water out (a slightly painful procedure), and then form the blob to suit your task, usually by just sticking it onto something and squeezing it into shape. Hot polycaprolactone sticks well to all sorts of surfaces, but not so well that you can't peel it off if you make a mistake. And you won't get scalded while doing this, because unlike water, the plastic is lousy at transferring heat to your fingers.

(If you heat polycaprolactone above 100°C, by, for instance, microwaving it instead of putting it in water, it apparently becomes a lot stickier, as well as much more able to burn you. So you might want to leave those higher temperatures to the rapid fabricators. I needed to smooth a little bit of my polycaprolactone blobs, so I wafted a small butane flame past the plastic. But then I smoothed it over with a damp screwdriver, instead of my finger.)

As polycaprolactone cools, it clouds up and stiffens, but does not appreciably shrink. If you haven't gotten your new plastic part shaped right before this happens, just pop it back in the water to re-soften. It's easier to re-shape polycaprolactone than it is to shape it in the first place, because there's less water to squeeze out. You can re-heat the plastic as many times as you like, too, and any excess can go back in the bag for later.

Polycaprolactone in the molecular weights that make it behave in this useful way is manufactured in vast quantities by at least two companies, Solvay and Dow Chemical. Which is great to know if you need a ton of the stuff, but not so much if you just want to replace a missing knob on a radio. (That was my first polycaprolactone project. It worked beautifully.)

Other companies repackage polycaprolactone in smaller quantities at large markups. "Polymorph", "ShapeLock" and "Friendly Plastic" are all polycaprolactone. The first two are very much the same; Friendly Plastic comes in a white-pellets version too, but is also available in a wide range of more-expensive coloured versions. You can colour polycaprolactone yourself, but if you need even, repeatable hues and/or metallic effects, and you don't need a huge amount of the stuff, then you'd probably do better just buying Friendly Plastic.

(The bone-white version is of course preferable, if you want to make creepy biomechanical thingummies.)

If you're in Australia and you just want to see what polycaprolactone is like, get yourself a hundred grams of "Polymorph" from Jaycar for $AU11.50. (Plus delivery, if you buy it online rather than over the counter.) That may go a surprisingly long way; I didn't weigh the Polymorph that went into my laser pointer, but judging by volume it was probably no more than 25 grams.

If you're in the States, there are lots of retail polycaprolactone sources. Try the Maker Shed.

If you're outside the States and want a larger, but not vast, amount of the stuff, many companies stand ready to rip you off.

You can place an international order at Shapelock.com and pay for it, with a pleasingly low shipping fee - and then they'll refund your money, because they don't actually ship overseas. And then they'll tell you to order from Jameco instead. Jameco's international shipping fees aren't mentioned on their site; you can place an order and give your payment info and wait for the delightful surprise, or you can e-mail them, whereupon they will inform you that their cheapest price to send a $US24.95 half-kilo of Shapelock to Australia is $US39.

Sorry. Just had to get that out of my system.

OK, here's how people outside the States - and possibly inside, actually, depending on how all the prices shake out - can buy polycaprolactone at a non-stupid price. Go to this eBay dealer in the UK (on ebay.com, on ebay.co.uk), who's currently on holiday until the 8th and has invisibilised their auctions, but will actually still let you place an order via this listing. They'll sell you 500 grams of Polymorph-branded polycaprolactone for £9.50 plus quite reasonable delivery, with a microscopic discount for multiple half-kilos.

[UPDATE: As pointed out in the comments below, that eBay dealer has a separate Web site too, from which you can download a great PDF about what you can do with Polymorph.]

To make sure I get my order in before all of y'all, I just ordered a key, man, for a total of £32.75 delivered to Australia. That's about $AU54.20, or $US49.80, as I write this.

A kilogram of polycaprolactone is quite a lot - especially when you consider the near-infinite reuseability of the stuff. Unless I suddenly start building sizeable structures, I don't anticipate having to buy any more for some years.

Jaycar offer discounts for bulk purchase, but a kilogram of Polymorph from them is still $AU89.50 ex delivery. So the eBayer in the UK looks like a good deal.

Hm. This post started out being about making a laser, and ended up about making freeform plastic bones. Eh - it'll do.

Do feel free to discuss either subject in the comments!

Posted in Animals, Electricity, Hacks, Handicrafts. 16 Comments »

For suitably small values of "infinite"

23 March 2010 — dan

One Jiang Gonglue has come up with this brilliant idea:

Infinite USB

(Via.)

Never mind the fractured English - these passthrough piggy-back plugs, called "Infinite USB", are clearly a work of genius.

And I'm not the only person who thinks so. Infinite USB won Mr Jiang an "iF Design Concept Award!

The only problem, really a very minor one, hardly worth mentioning, is that each of these cables is presumably a two-port bus-powered hub. And the USB spec forbids plugging one bus-powered hub into another one.

The official specs for USB also prohibit plain extension cables, mind you, and most extension cables actually work fine with most devices, provided you aren't greatly exceeding the five-metre cable-length limit. And, similarly, in reality you often can plug one bus-powered (or "passive") hub into another and have it work, more or less. You may not be able to use all of the ports - which is less of a problem if there are only two, of course. And you're quite likely to find you only get a USB-1-speed connection. But passive-hub into passive-hub will usually sorta-kinda work. Especially if the powered port your illegal chain of bus-powered hubs is plugged into can deliver more than the half-amp of current that the USB spec says it should.

The reason why daisy-chaining passive hubs works at all, by the way, is that many bus-powered USB hubs report themselves as being self-powered. A real self-powered hub is one with its own DC power supply, which allows it to deliver the full 0.5A of current on each of its ports. But there's nothing, except the ethics of the manufacturer, stopping a bus-powered hub from declaring itself to be self-powered, whereupon it'll at least attempt to work if plugged into another passive hub. A passive hub that admits that it's passive won't work at all if you plug it into another, similarly-truthful passive hub.

(Most self-powered hubs will work even if you don't connect their plugpack power supply, but they'll only be bus-powered when the power supply is not connected. I wonder how many of them report themselves as bus-powered when the plugpack's not plugged in?)

So the Infinite USB plugs aren't abominations like male-to-male plug adapters and such. They might work. A bit.

I'd be pretty surprised if even the green-striped #3 one in the above picture worked, though. I'd bet money that the apple-cart would have been thoroughly upset at least by the time you plugged the #4 grey one in. Oh, and if the Infinite USBs reported themselves honestly then, of course, none after the original #1 blue plug would work.

But, as we've seen before, trivial considerations like whether the product could ever possibly work are not an obstacle for hard-working design students and the institutions that give them awards.

Posted in Electricity. 23 Comments »

Today, on "Surf-Celebrity Science Class"...

10 March 2010 — dan

Herewith, one of the most pleasing correspondences I've ever had with someone who originally contacted me with bold new scientific ideas.

Usually, such exchanges go kind of like this. This went much better.

And it turned out I was talking to someone famous, to boot!

From: Tom
To: dan@dansdata.com
Date: Mon, 8 Mar 2010 02:15:07
Subject: Magnetic healing?

I'm on some kind of similar path as you. In any case, really appreciated your summary of kinds, costs and usage of neodymium magnets.

I came across a guy who explained to me that microbes have a tough time living in changing magnetic fields. Germs, viruses... Perhaps that's one reason exercise is beneficial. The electricity delivered in pulses to muscles, causes pulsing magnetic fields all along the way.

This guy and his pals were making "Thumpers" (maybe spelled differently). They were buying Radio Shack strobe lights, then attaching coils in place of lights, and maintained that pulses of magnetism could cure bacteria deep within the body. His wife, for example, had some sort of deep sinus infection that he'd healed.

I talked long distance to the guy via telephone (back in a day where it made a difference that phones were far apart) and compared notes on power. I asked him to describe the results when he applied his thumper pulses to his television screen... again, this was before flat screens so that you'd wiggle a magnet in front of a computer monitor or TV and it would produce all kinda weird patterns. His thumper was effective within a foot or so. Meanwhile, I was twirling a couple of not all that strong cylindrical magnets two feet from my screen and it was going nuts. My magnets were like the size of a pack of Life Savers. These were suspended from my fingers by a loop of rubber band which I could then twirl. Wind and then it would unwind, kind of thing.

Point is, experiment with infected sores by waving the sore part back and forth by a neo magnet. Or, build a little rubber band twirler and try it out next time you have, say, a toothache. Twirl it by your teeth and see if it kills off the tooth caries.

Tom

My reply:

I don't think it's true that magnetic fields kill microbes. And if the incredibly weak magnetic fields from natural electrical activity in the body made life "tough" for microorganisms, walking past an electric oven would kill all the beneficial flora in your gut.

With regard to the magnetic "thumpers", the big question is, "How do the pulses know good bacteria from bad?"

(It turns out that magnetic "thumpers" are also known as "pulsers", and are quite popular among people who usually also believe that Hulda Clark and/or Royal Rife could actually cure just about everything with their electrical "zappers".)

If sinus infections never went away by themselves, then curing one with some gadget would be impressive. When you're dealing with diseases that do go away by themselves, and don't even have clear endpoints or objectively measurable symptoms, though, it's not a great idea to conclude that whatever you did before the disease went away must have cured it. This sort of uncontrolled test may point you toward a real phenomenon that you can then investigate properly, but all it proves by itself is that whatever you did before the disease went away didn't stop the disease from going away.

The "thumper" idea has the same problems as many other half-baked alternative-medicine theories. Magically targeting bad bacteria while leaving good ones, a simple scientific process with Nobel-Prize-worthy effects that would have been discovered by accident ten thousand times before 1910, et cetera.

Yes, CRT monitors are very sensitive to magnetic fields. Which is good, because otherwise the dot would just sit there in the middle and you'd have to wave the whole monitor around really fast to make an image! (You could, to be pedantic, use oscilloscope-style electrostatic deflection instead of magnetic deflection. But electrostatic deflection can't bend an electron beam nearly as sharply as a magnetic field; a 26-inch electrostatic-CRT TV could easily be six feet deep.)

Magnetic fields affecting electron beams are a real physical effect, discovery of which was an important, and inevitable, part of the development of human knowledge about electromagnetism. William Crookes (of the eponymous radiometer, among other things) probably did the magnetic-deflection trick first, but if he hadn't, someone else would have (and, indeed, did), well before the end of the 19th century.

Magnetic fields of modest strength affecting biological organisms, on the other hand, is a claim frequently made, which could easily be tested in a kitchen with less than a hundred bucks worth of basic scientific equipment, but which has never thus been proved.

(You can set up a pretty respectable molecular biology lab for under $US1000, these days. Praise eBay!)

If you walk through a really monstrous magnetic field - the kind with big warning signs about not entering the room unless you've ditched every metal object on your person, even if you're willing to sign an affidavit saying that those objects are not ferromagnetic at all - then you're likely to feel funny. Focused and pulsed magnetic fields directed into the brain can also create peculiar effects. Pulsed magnetic fields may even improve healing, though the verdict isn't quite final on that one yet.

But even magnetic fields so powerful that the feeble diamagnetism of water becomes sufficient to levitate living creatures do not, so far as anyone can see, kill so much as one lowly bacterium.

The notion that field strengths that aren't sufficient to rip a belt buckle clean through the leather could somehow kill germs is, thus, exceedingly difficult to defend.

I cordially invite you to set up some Petri dishes and conduct your suggested tooth-decay experiment. You may be the one who makes the breakthrough!

Tom replied:

I appreciate your thorough and helpful reply. However, I'm not coming from any place of proof. Just suggesting a possibility. As to selectively killing bad flora, that idea never entered my head. The point is that possibly there's something in the idea to consider rather than criticize.

As to a notion you seem to entertain I'll paraphrase as, "If that idea was any good, it would already have been invented". This is a very discouraging idea. The fact is, that in 1850 a bill was put before Congress to close the Patent Office because they thought everything of worth had already been invented. Wrong. Looking back from say the year 3000 we'll see that relatively little had been discovered by 2010.

As to the use of alternating magnetic fields as a deterrent to bacterial buildup (good or bad), I'd be willing to bet that in the not too distant future, it will be determined that the relatively strong magnetic fields used for MRI are curative of certain chronic disorders.

As a youth, my mother told me repeatedly that my ideas were probably already thought of. However, in 1971 I thought up something called the boogie board, and created its manufacturing process. 20-50 million of them have since been built.

Anyhow, best wishes.
Tom

Thanks for not flying off the handle over my typically "thorough and helpful reply" :-).

You may not be "coming from any place of proof", but neither is anybody who's postulating some new scientific claim.

I've explained why the "possibility" you mention is extremely implausible. It would be easy to test, people have tested similar claims many times, and as far as I know, it's never panned out. People have incidentally tested these claims countless times, actually; any time germs and a magnetic field are together and someone checks on the germs later, that's a test of your claim.

I mean, just to pick one example, "magnetic stirrers" are a normal piece of lab equipment. A rotating magnetic field from below a container spins a little stirring rod inside the container. Such stirrers are used in biology labs, and have been for decades. To my knowledge, no germicidal properties from the magnetic field have ever been noticed.

And, again, this'd be Nobel-Prize material. Even if you can only kill germs on inanimate objects by subjecting them to magnetic fields, that'd be a billion-dollar discovery. It'd be a wonderful alternative to autoclaving and chemical disinfectants.

So sure, possibly there's something in the idea. Possibly, Elvis is alive, and currently serving as Emperor of All the Underground Cities of Mars!

[UPDATE: Magnetotactic bacteria actually do respond to magnetic fields, and can in practice be manipulated to do strange things under magnetic control. This doesn't have anything to do with disease control, though.]

On top of the fact that this idea has been tested zillions of times - mainly accidentally, but I'm sure also deliberately; the idea that magnetism is somehow therapeutic is an old one - I've also explained why your friends with the magnetic strobe-circuit doodads are making inconsistent claims in the first place. Somehow, the magnetic fields kill "bad" bacteria while leaving the "good" ones alive.

The magnetism obviously doesn't kill the good bacteria, because otherwise anybody who passed through a strong magnetic field - or used one of these "thumper" things, in case it's field gradient or pulse frequency or something that's critical, not just field strength - would develop the same diarrhoea you get if antibiotics kill off your gut flora.

If you managed to confine the field to your armpits, though, it'd cure underarm odour!

There are quite a lot of beasties that live in and on the human body, more than a few of which would cause obvious effects if you killed them all off. And yet people who spend their whole working life right next to giant superconducting magnets, and people who work in magnet factories, and people who work next to the giant busbars in power stations and blast furnaces, do not exhibit any signs of loss of bacteria. (I'm also willing to bet that if you swab the bus bars, the surfaces of the magnets, et cetera, and culture what you find, there won't be any fewer, or any different species, of microorganisms than you'd expect.)

See also, for instance, people who believe that "colloidal silver" is some sort of cure-all. In that case they've at least got some factual basis for their claims; metallic silver has real antiseptic properties. But they go from that to saying that tiny silver particles (or concoctions that they just allege contain tiny silver particles...) will, if you drink them, be Good For What Ails You, and magically not kill any good bacteria. Which is the point where they and empirical evidence part company, and also the point where they stop making even logical sense.

David Hume's famous statement that "A wise man proportions his belief to the evidence" does not mean that everybody should shut up and just believe whatever scientific orthodoxy, or the government, or some church, says. You're allowed to seek your own evidence, and to judge what evidence presented by others is plausible. You don't need a diploma to be a scientist. A scientist is just someone who does science.

But this doesn't make all claims plausible, or worthy of investigation. Life's too short to follow up on every possibility, no matter how unlikely.

Regarding the "bill to close the Patent Office" - now, see, that's not true either!

This urban legend is usually presented as "a US Patent Office guy in the 19th Century said that everything that could be invented already had been". The version of the story that says it was a Bill to close the patent office also exists in numerous versions. Nobody can decide what year this was supposed to have happened!

Sure, maybe in the future we'll look back on our skepticism about therapeutic magnetism and wonder how we could ever have been so wrong. But nobody's noticed any germ-killing effects yet, though. And lot of people have had MRIs. And most of those people have been sick.

Scientists all over the world are combing through every possible statistical source to find something publishable. A correlation between people having MRIs and infections clearing up would be a brilliant one. No luck so far, though.

I think the relevant saying is "it's good to have an open mind, but not so open that your brain falls out".

Regarding your mother's incorrect assumption that your ideas probably weren't new - indeed, the man who says it can't be done should not interrupt the man who is busy doing it. But this does not mean that the man who says it can't be done is the one who has to put up or shut up!

I'm reminded of this:

Small child: "My mummy says when I grow up, I can be anything I want to be!"
Adult: "What do you want to be, then?"
Small child: "I'm going to be a GIRAFFE!"

You might not actually choose to dash the child's hopes at the time, but you can still be pretty sure that kid's not going to grow up to be a giraffe, a fire engine, a jumbo jet, et cetera. This certainty does not make you close-minded.

However, in 1971 I thought up something called the boogie board and created its manufacturing process.

Wait - you're "the" Tom Morey?! Awesome! If you were here in person I'd ask for an autograph!

(This still doesn't make you exempt from having to prove your scientific claims, though!)

I should have known I was talking with an engineer :-). Take care that you don't come down with "Engineers' Disease", though - the tendency for people with a high level of technical knowledge to decide that their knowledge must be applicable to specialised fields that they don't actually know a lot about. The world teems with distinguished engineers who're spending their later years in futile pursuit of perpetual motion, antigravity, cure-alls and so on.

Now, just because someone is an engineer, and now thinks they're onto something big that isn't quite in their area of expertise, doesn't mean they're wasting their time. But this does seem to be a common failure mode for human minds, and I shudder to think how much hard work has been ploughed into these sorts of hopeless pursuits.

Tom replied:

Dan,
Thank you for all the kind attention. You've developed a very thorough and convincing mind.

Interestingly, you hit quite a few nails on the head. Example: Yes... at age 75 now, having dabbled in way many things, more recently I've made up my alleged mind to spend the rest of my days of developing practical transatmospheric "flight" for the common man. Although I'm making progress and excitedly so, I certainly could be pissing into a windmill or whatever the phrase is. Then again, what FUN!

Health and healing...? About all I've really figured out so far is that not smoking, not drinking, plus getting into the ocean more often than not, exposing myself to ONLY moderate exercise and yet semi-regular doses of cold water shower finishes... has kept me fairly healthy.

Even so, right now I feel like the second half of the avocado that was perfect a couple of days ago when you ate the first perfectly flavored and textured half; then put this second half in the fridge. Now, spoon in hand, ready to dive in... fridge door still open and, "Hey! Where did those stringy things come from"?

Your arguments about all the folks who are regularly working with magnets, stirring fluids in labs etc, were very thought provoking. Thank you.

The whole topic reminds me of a curious event a few years back when our apartment was inundated by ants. In fact the suckers were EVERYWHERE for blocks around; no stain or crumb was left un-munched by the buggers. Funny thing was a good many took up residence in, or at least were staying alive in, the microwave oven! I'd swing the door open, stick in a cup of hot water for tea, and notice dozens of ants meandering around in there. Too busy at the time to do away with any of them, I'd simply shut the door, set the timer for two minutes and bzzzzzzzzzzzzzz. Then open the door, take out the boiling hot tea... and damn if they'd changed at all. Still milling around, none of their little feet up in the air.

Go figure?

Anyhow, thanks for your patient ponging of my pings. Aloha, And good bye. Am going off line for the next couple of weeks, So Cal is too cold for the bones. Heading for Cabo to drink in lots of light... roll in the sand and slosh around in the sea.

Tom

The ants survive because they're too small to be affected by the microwaves, which are "micro" by radio-wave standards, but still have a quite large wavelength. That's why you can see into the oven through that perforated metal on the door, without any microwaves getting out. Note that the perforations are similar in size to an ant!

You can actually drill quite a large hole through the metal around a microwave oven, to for instance install a "lipstick" camera, without any radiation escaping.

If you just put the camera inside the oven and turn it on, the camera's electronics will die almost instantly and obvious macroscopic sizzling and sparking will be happening within seconds.

If the camera's on the other side of a hole big enough to stick your finger through, though, it'll be fine.

(Most cockroaches are juuuust big enough for a microwave to fry them, if you give it a little while. The bigger the roach, the more trouble it'll be in.)

See also the magnificent series of Unwise Microwave Oven Experiments by Bill Beaty, who's one of my heroes.

I've microwaved many CDs, but haven't yet done the fantastic beer-bottle stunt!

Posted in Electricity, Science. 24 Comments »

Long word, starts with P, solves all our problems...

7 March 2010 — dan

A reader writes:

I've just read an article in Popular Science about Sun Catalytix' "artificial photosynthesis" being used to power houses.

Which got me questioning, is it even viable? Using water as an energy source, as you've said previously, involves electrolysis, and the power it can generate won't exceed what was used in the electrolysis process.

He is using sunlight as the energy source, so I guess it's not one of those water-powered-car scams. But wouldn't it be easier if we use batteries to store the electricity from the solar panel?

And where does the photosynthesis comes in?

Please enlighten me here.

Andhika

The photosynthesis is supposed to replace the electrolysis. See, electrolysis is really inefficient, and batteries aren't awesomely efficient either, and you need a pretty darn big battery bank, which wears out, to run a whole house. But photosynthesis can manage efficiency as high as 8%, so... uh...

Look, buddy - "photoelectrochemical cell" is 24 letters - 25, including the space. We're already really pushing the brainpower of the voting public with the word "photosynthesis", all right?

I started doing a series of actual calculations about this, then stopped, because there's not enough information in the article, the marginally-more-informative Scientific American article, or...

...the less-than-entirely-satisfying accompanying video, for any really solid numbers to be made.

(You can't say that that video doesn't alert the viewer to the fact that it's not aimed at people who know a single damn thing about anything. "In the next forty years, you're going to need more energy than is available from every source you can imagine", says actual MIT professor Dan Nocera. Never mind that decreasing human energy consumption, while continuing to improve quality of life, is a real and serious goal; I can also "imagine" fusion power, dude. So clearly I'm not part of this clip's intended audience. Paging Mr Bush; Mr Bush to the coal-fired courtesy phone, please...)

In neither the Popular Science nor the Scientific American piece does the writer seem to have paid any attention to that core "30 square metres of solar cells in Boston making 30 kilowatt-hours in four hours" claim. It seems fishy to me. As does the idea that this magical catalyst is actually a useful breakthrough.

I'd be willing to believe that this was a real, if slightly oversold, option, if it weren't explicitly about a system that you're supposed to install on your roof to run your house. This didn't, early in the Scientific American article, seem to be the case - "We emulated photosynthesis for large-scale storage of solar energy", says Dan Nocera.

And yeah, you might perhaps actually be able to get the stated output from the stated area of cutting-edge panels at Boston's latitude if they're all on expensive sun trackers and/or overpumped by extra reflectors and water-cooled. Which they can be, relatively economically, if they're part of a municipal solar farm and not stuck on someone's roof.

No matter how good the magic catalyst is, though, nothing's going to give you all of those 30 kW/h back again, and Mr Nocera goes on to say "...We need to do it the old American way of making one small one and then manufacturing that system to give it to the masses."

Which brings us back to the cheerful notion of an easy $35,000 worth of cutting-edge solar panels and sun-tracking hardware on everybody's roof, much of which will need repairs after every storm. Unless you ditch the trackers, reflectors, cooling system, et cetera, in which case the stated energy output becomes impossible with even maximum-efficiency commercial solar cells of the stated area. You're likely to need something like twice that area for well-aimed never-shaded cutting-edge commercial cells, an easy three or four times the area for cheaper panels installed on a real-world roof...

A couple of commenters on the articles, and on this Engadget writeup, managed to briefly poke their heads above the SOCIALIST TEA PARTY MASONIC JOHN BIRCH GRR comments to point out some of these issues.

Fortunately, even if Mister Nocera is being outrageously misquoted (occasionally by himself!), his company is only about the hundred-thousandth-worst outfit to have had US taxpayers' money sprinkled upon it lately. And who knows, maybe there's something to this, even if it depends upon solar panels that haven't yet been invented, or something.

I wouldn't rush out to place a deposit, though.

Posted in Electricity, Science. 11 Comments »
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