Death of RAID predicted, film at 11

23 October 2008 — dan

From a reader:

Love to hear your take on this: Why RAID 5 stops working in 2009.

That article by Robin Harris is more than a year old, but was suddenly linked hither and yon in the last few days. Its thesis is that because RAID array capacities are approaching unrecoverable read error rates, if one disk in your RAID fails, you'll very probably get a read error from one of the other disks in the course of rebuilding the array, and lose data.

This basic claim is true, but there are three reasons why this problem is not as scary as it sounds.

1: Losing one bit shouldn't lose you more than one file. Consumer RAID controllers may have a fit over small errors, but losing one file because a drive failed is seldom actually a serious problem.

2: Putting your valuable data on a RAID array and not backing it up is a bad idea even if disk errors never happen. One day, you are guaranteed to confidently instruct your computer to delete something that you actually want, and RAID won't protect you from that, or from housefires, theft of the drives, and so on. You still need proper backups.

3: If you're going to build a story on statistics, it helps a lot if you get the statistics right.

Robin Harris says it is "almost certain" that 12 terabytes of disk drives with a one-in-12Tb read error rate will have an error if you read the whole capacity.

This statement is wrong.

Actually, the probability of one or more errors, in this situation, is only 63.2%. When you know why this is, you discover that there's less to fear here than you'd think.

(Robin Harris is not the only sinner, here. This guy makes exactly the same mistake. This guy, on the other hand, says one error in ten to the fourteen reads gives you "a 56% chance" of an error in seven terabytes read; he's actually done the maths correctly.)

The mistake people make over and over again when figuring out stuff like this is saying that that if you've got (say) a one in a million chance of event Y occurring every time you take action X, and you do X a million times, the probability that Y will have happened is 1.

It isn't.

(If it were, then if you did X a million and one times, the probability that Y will have occured would now be slightly more than one. This is unacceptably weird, even by mathematicians' standards.)

What you do to figure out the real probabilities in this sort of situation is look at the probability that Y will never happen over your million trials.

(If it matters to you if Y happens more than once, then things get more complex. But usually the outcomes you're interested in are "Y does not happen at all" and "Y happens one or more times". That is the case here, and in many other "chance of failure" sorts of situations.)

To make this easier to understand, let's look at a version of the problem using numbers that you can figure out on a piece of paper, without having to do anything a million times.

Let's say that you're throwing an ordinary (fair!) six-sided die, and you don't want to get a one. The chance of getting a one is, of course, one in six, and let's say you're throwing the die six times.

For each throw, the probability of something other than one coming up is five in six. So the probability of something other than one coming up for all six throws is:

5/6 times 5/6 times 5/6 times 5/6 times 5/6 times 5/6.

This can more easily be written as five-sixths to the power of six, or (5/6)^6, and it's equal to (5^6)/(6^6), or 15625/46656. That's about 0.335, where 1 is certainty, and 0 is impossibility.

So six trials, in each of which an undesirable outcome has a one in six chance of happening, certainly do not make the undesirable outcome certain. You actually have about a one-third chance that the undesirable outcome will not happen at all.

It's easy to adjust this for different probabilities and different numbers of trials. If you intend to throw the dice 15 times instead of six, you calculate (5/6)^15, which gives you about a 0.065 chance that you'll get away with no ones. And if you decide to toss a coin ten times, and want to know how likely it is that it'll never come up tails, then the calculation will be (1/2)^10, a miserable 0.00098.

In the one-in-a-million, one-million-times version, you figure out (1 - 1/1000000)^1000000, which is about 0.368. So there's a 36.8% chance that the one-in-a-million event will never happen in one million trials, and a 63.2% chance that the event will happen one or more times.

OK, on to the disk-drive example.

Let's say that the chance of an unrecoverable read failure is indeed one in ten to the 14 - 1/100,000,000,000,000. I'll express this big number, and the other big numbers to come, in the conventional computer-y form of scientific notation that doesn't require little superscript numbers. One times ten to the power of 14, a one with 14 zeroes after it, is thus written "1E+14".

The chance of no error occurring on any given read, given this error probability, is 1 - 1/(1E+14), which is 0.99999999999999. Very close to one, but not quite there.

(Note that if you start figuring this stuff out for yourself in a spreadsheet or something, really long numbers may cause you to start hitting precision problems, where the computer runs out of digits to express a number like 0.99999999999999999999999999999999999999 correctly, rounds it off to one, and breaks your calculation. Fortunately, the mere fourteen-digit numbers we're working with here are well within normal computer precision.)

OK, now let's say we're reading the whole of a drive which just happens to have a capacity of exactly 1E+14 bits, at this error rate of one error in every 10^14 reads. So the chance of zero errors is:

(1 - 1/(1E+14))^1E+14

This equals about 0.368. Or, if you prefer, a 63.2% chance of one or more errors.

Note that the basic statement about the probability of an error remains true - overall, a drive with an Unrecoverable Read Error Rate of one in ten to the fourteen will indeed have such an error once in every ten to the fourteen reads. But that doesn't guarantee such an error in any particular ten to the fourteen reads, any more than the fact that a coin comes up evenly heads or tails guarantees that you'll get one of each if you throw it twice.

Now, a RAID that's 63.2% likely to have an error if one of its drives fails is still not a good thing. But there's a big difference between 63.2% and "almost certain".

(Note also that we're talking about a lot of data, here. At fifty megabytes per second, ten to the fourteen bits will take about 2.8 days to read.)

Getting the statistics right makes the numbers look proportionally better if the error rate can be reduced.

If drive manufacturers manage to reduce the error rate by a factor of ten, for instance, so now it's one in every ten to the fifteen reads instead of every 1E+14, the chance that you'll get no such errors in a given ten to the fourteen reads improves to about 90.5%.

If they reduce the error rate all the way to one in ten to the sixteen, then ten to the fourteen reads are 98.9% likely to all be fine.

I'm not saying it's necessarily easy to make such an improvement in the read error rate, especially in the marketing-bulldust-soaked hard-drive industry.

But neither is the situation as dire as the "almost certain" article says.

All who commit such crimes against mathematical literacy are hereby sentenced to read John Allen Paulos' classic Innumeracy.

(This is not a very severe sentence, since the book is actually rather entertaining.)

Posted in Nerdery, Science. 18 Comments »

Laws of Physics 2,937,290,458,937, magic fuel savers 0

14 October 2008 — dan

I know you were all perched on the edge of your seats about that Moletech, or possibly MTECH, Fuel Saver thing.

Well, The Western Australian Department of Consumer and Employment Protection, or NAMBLA DOCEP, has reached an "undertaking" with the two companies responsible for The MoleWhatever Fuel Saver, in which those companies agree to stop selling their useless gadget in Western Australia and DOCEP agree to not kick their miserable scamming arses into the Indian Ocean.

(I paraphrase lightly. Here's the DOCEP page about this. I've also got a copy of the official PDF press release here.)

I don't know whether the Federal Government has reached an opinion about Moletech, but it didn't look good for them in January.

The Western Australian developments were brought to my attention by the proprietor of the Thinkingisreal blog, who saw a story about the "undertaking" on the WA edition of of the sterling tabloid-TV current affairs program Today Tonight.

Today Tonight and their cousins at A Current Affair appear to decide whether to run an approving or a scathing story about nonsense diets, umpteen useless fuel savers, and psychics, by flipping a coin. Actually, I think dice may be involved, with a roll of 24 or higher needed to get a critical story.

But TT are really solidly committed to this story. Just look at their Consumer Protection page!

In case you're coming to this post a while after I wrote it and that page now actually has some content, be advised that at the time of writing, and since TT ran the story, the sum total of the non-navigation content on that page - which is presumably meant to provide background information for every consumer-protection story the show has ever run - is:

Fuel Saver Ban
Consumer Protection
1300 30 40 54

Seriously, that's it.

They don't even say what Fuel Saver they're talking about.

Awesome work, guys. Bonuses all round.

(I searched for other pages on the 7perth.com.au site that mentioned this, and found the same "Fuel Saver Ban" snippet on this page, which contains what looks like a nose-to-tail site-content dump. The title of that page is - again, if the page isn't there by the time you read this, be advised that I am not making this up - "Alzheimers Cure". And the page-content below the "Fuel Saver Ban" snippet is about a spray-on cure for arthritis pain that uses "Herbal Synergism". Two pages-worth up from the Fuel Saver snippet is... a miracle diet, this time based around milk protein. Magnificent.)

Thinkingisreal had a blog post up about this, but pulled it because there wasn't yet any solid info about the ban on the Today Tonight or DOCEP sites (the press release was mentioned on this DOCEP page, but the link to it was broken. Now the official statement is up. Here's DOCEPs list of current media statements).

Anyway, apparently Today Tonight did a previous story on the Moletech gadget, in which they found "promising results" in their entirely science-free investigation. That story is still proudly mentioned on the home page of moletech.us.

(I originally thought TT had, being at least slightly honest, mentioned this previous story in the most recent one. Thinkingisreal says he doesn't actually remember them doing so.)

But now, wouldn't you know it, TT have changed their minds, and decided that this zillionth example of a fuel conditioner that's supposed to work by some sort of molecular balderdash ("nano negative ions!") is just as useless as all the rest.

That quote from Band of Brothers springs to mind, yet again.

Posted in Cars, Scams, Science. 4 Comments »

My third hip

6 October 2008 — dan

As I mentioned in this article, as soon as I saw Theodore Gray's prosthetic hip joint, I had to get one of my own. (Theodore's is one of the samples for his Periodic Table Table; he's pretty sure it belongs in the cobalt collection.)

Artificial hip

And here mine is. I bought it on eBay; it cost me a total of $AU23.38 including delivery.

I've only got the hip part, not the corresponding socket part - which in this case would have been polyethylene, I think. But this is the interesting part, if you ask me. Mine even has a couple of nifty holes in the shaft, instead of the less elegant solid shaft of Theodore's. As I mentioned in that article, I find it makes a very acceptable ray gun.

I think it's probably made from a cobalt chrome molybdenum alloy. It's very slightly magnetic; you can't tell if you're just holding even a rare-earth magnet in one hand and the hip in the other, but when I hung a magnet from a string, I could get it to stick to the implant very slightly.

I'm not sure what company made it. There's a logo on the side like an R with a line around it, like so:

R logo

If you recognise that, drop me a line.

After the logo, there's "52-0346 46mm" (46mm is the diameter of the ball on the end), then "CC" on the next line. Further down the shaft there's a serial number, T00991004.

I'll have to buff all that stuff off before I try to pass the implant off as alien technology.

(See also: My bone chisel!)

UPDATE: One or another of my readers can reasonably be expected to know absolutely anything, so I now know exactly what this prosthesis is.

Take it away, Charles the anaesthetist:

Your prosthesis is an Austin Moore Hemiarthroplasty prosthesis [yep; now that I've got that string to search for, I instantly found it], used to replace the femoral head in cases of subcapital fracture (fairly high) of the neck of femur where the fracture site is high enough to probably affect the blood supply to the femoral head, leading to necrosis. Because of this you can't just screw the fracture together (search DHS, CHS, or IMHS).

Neck of Femur fracture (NOF) is an old person's fracture, as such not a great load is expected on the hip, in terms of use and duration, thus the acetabular side (socket) is left as is (which is why the head is so large: total hip replacment prostheses have a much smaller head diameter).

An Austin Moore is uncemented, too: you ream to size and bang it in. There are cemented hemiarthroplasties that are a sort of half way position (more stable and durable, less loosening) between this and a THR (total hip replacement), but cementing a prosthesis in this patient population has a high intraoperative morbidity and mortality itself.

There is a very high mortality post NOF: not due solely to the fracture, but due to the clinical situation of these patients. If a younger person happened to NOF themselves, you might pin it first if you thought the head had any chance of survival, but if not, a THR is better.

The "R" is Richards, an orthopaedic company since absorbed into Smith and Nephew, along with others.

I used to have a Austin Moore as a gear shifter in my Kingswood wagon: it fit nicely in the hand!

Posted in Science, Toys. 11 Comments »

One of these things is not like the other

5 October 2008 — dan

I'm a bit late on this one, but it's so hilarious that I simply must tell you about it, just in case you haven't seen it yourself.

This is, if you ask me, even funnier than the well-documented evolution of that Intelligent Design textbook.

I hadn't actually read Richard Dawkins' blog post about the hilarious stupidity of Turkish creationist Harun Yahya's glossy but rather poorly fact-checked book "Atlas of Creation".

(If Harun hasn't gotten around to sending you one for free yet you may be able to find a seller on Amazon!)

"Harun Yahya" is the pen name of one Adnan Oktar, a leading light in the burgeoning field of Islamic creationism, in which Muslims strive to demonstrate that their newer and more vibrant religion can outdo Christianity in every field, the stupider the better. Islamic creationism has found a de facto home in Turkey, and a de facto leader in Harun/Adnan. He has a Web site.

The problem Dawkins found with Atlas of Creation (instantly, upon opening the book at random) is not the usual distortions, misquotes and plain old lies that are the stock in trade of the jobbing creationist. The problem, rather, comes from the fact that the book contains many comparisons between fossil organisms and modern ones that're supposed to demonstrate that those organisms have not changed at all over millions of years. That is the entire thesis of the book.

That, in itself, would only actually be an argument against evolution if it were hard to find organisms which have changed over the years, which is of course not at all the case. Environments and ecological niches tend to change, applying selective pressure to the species that live there, which then change, or become extinct. Most organisms are not ferns or crocodiles, pretty much as adequate to their task today as they were before the first mammal had drawn breath.

The standard creationist tactic to deal with this awkward situation is to declare anything that looks as if it's changed to actually be two, or three, or as many as are necessary, entirely different species with no relationship at all. Any time you find a "missing link", they can therefore just say that now there are two more gaps that remain tellingly unfilled.

(In related news, it is physically impossible to close a door.)

But never mind that, because Dawkins found that the Atlas of Creation frequently fails to actually compare a fossil creature with a modern version of the same thing at all.

The first such mistake he found, where he first opened the book, was the claim that a fossil eel hadn't changed at all when compared with... a modern sea snake, which is actually a very different species.

There were many more. Sometimes the book fails to even compare a fossil with a living creature in the same subkingdom.

But the very finest comparisons were discovered by entomologist Steve Lew.

The makers of the Atlas of Creation, you see, apparently kept production costs down by just lifting pictures from all over the Internet. The problem with doing this - besides the tedious copyright-infringement stuff - is that you can't reliably tell what organism a picture is of just by looking at it. (Especially if you've got the level of knowledge about biology that's typical among famous creationists.) Go to a proper stock-photo outfit (or, in this case, some biology-photos resource, I suppose) and you're likely to find that when you ask for a picture of a caddis fly, you get a picture of a caddis fly.

If, on the other hand, your image requests are made in a more informal, Google-Imagey sort of way, you may give yourself away just a teeny bit.

As I write this, the third Google Images hit for "caddis fly" is from grahamowengallery.com - specifically, this page. If you go to that page, you shouldn't need even a rudimentary command of the English language to see that Graham Owen makes wonderfully realistic fake insects, using fly-tying techniques. A lot of his work is actually, in theory at least, usable for actual fishing, because it's tied around a hook like any other fly.

This detail escaped the worthies putting together the Atlas of Creation.

Creationism at its finest

So there it is, bold as brass in the middle of their glossy book: A fly in amber in the background, and a fishing fly with a bloody great hook sticking out of its arse in the foreground. They just Photoshopped out the background of Graham Owen's picture.

They also knocked off Mr Owen's "Red Hardy Spider" image from the same page. The hook's much harder to see there, but the nature of the page the image came from is just as bloody obvious.

(UPDATE: I e-mailed Graham Owen about this, and he told me that he's made a Web page about the image thievery! it turns out that they also knocked off his picture of a mayfly. And Graham confirmed for me that the makers of Atlas of Creation didn't even ask permission to use the pictures, much less pay to license them. Graham's now asked them about it, but they apparently can't take any time off from their busy job of being very pious and respectable followers of God to send him an answer about why they copied his photos without paying.)

Mr Oktar spoiled all the fun by writing a reply to Richard Dawkins, a Turkish newspaper that picked up the story, all the cool kids at school who won't play with him, et cetera, complaining about Dawkins' "terrible ignorance". He argues that "whether or not it is a model makes no difference", since the picture represents something that does actually exist, and then goes on to say "The fact that demolishes evolution is that the creature has remained unchanged for millions of years and that it completely refutes evolution."

Well, if it completely refutes evolution then I suppose it must demolish it as well, not to mention contradict it, destroy it, pulverise it and give it a very stern talking to. But I think I must have missed the part where evolution says that the phenotype of an organism must change over time.

The only reason to think this is the case is if you believe in the frequently-espoused but completely stupid "ladder" kind of evolution, where everything's striving to get "higher" all the time, and will surely achieve this goal. This is preposterous on its face - all these billions of years, and we've still got bacteria - but it's ubiquitous in lousy sci-fi. There, "evolutionary level" is a property that can be freely pushed one way or the other, so a ray gun or a defective time machine or whatever can "de-evolve" people into apes, or "evolve" them into huge-brained psychic ectomorphs or similarly super-intelligent "beings of pure energy".

If you don't get all of your knowledge of evolution from that one God-awful episode of Voyager, though, the fact that Richard Dawkins "never goes into the question of whether or not the caddis fly is still alive today" is not, as Yahya says, a dead giveaway that evolution is completely bogus.

Dawkins is, I think, reasonably sure that people already know that caddis flies still exist, and that ancient ones looked much like modern ones. If there's no great selective pressure on an organism, you shouldn't expect it to change much. If a particular organism was already very well adapted to its environment, and its environment has not greatly changed, then neither does the organism. Stop me if I'm going too fast for you here, creationists.

I think it still matters that they made such lousy image choices, though, because it's an entertaining case in point of the sloppiness of most, if not all, creationist arguments. Comparing fossils with unrelated animals, or fishing flies, is like your candidate making a speech in front of a picture of a military hospital... that turns out to actually be a picture of a similarly-named middle school. It shows that you're just not paying attention, even when you'll look like idiots if you get it wrong.

This doesn't, of course, matter to the creationist target market, who can't be expected to make it through any book that doesn't have pretty pictures (frequently including whatever holy book they claim to so fervently believe).

Adnan Oktar actually does, of course, believe that no species has ever significantly changed over time. (He's also pleased to point out that all terrorists are atheist "Darwinists"! I suppose that'd explain why they hate American soldiers so much.)

It's a little difficult to defend these beliefs logically, so he's taken the popular option in this situation and defended them legally instead. Richard Dawkins' site is, therefore, now unavailable in Turkey (or supposed to be, anyway), along with a variety of other sites that've irritated someone there. (Oktar's lawsuits are currently protecting Turkish Internet users from the whole of WordPress.com and Google Groups; the Turkish government blocks several other sites. At one point, the Turkish block list apparently included, on account of a typographical error, the unused imbd.com domain instead of the Internet Movie Database.)

Oktar's probably a bit too busy to start shooting off more lawsuits at the moment, since he's appealing his recent conviction for "creating an illegal organization for personal gain"; this is the latest instalment of a particularly distasteful story.

(When looking for more info about that, I found this thread on James Randi's forum, where one commenter points out that one of the numerous defective comparisons in the Atlas of Creation is between a fossilised spider crab and a contemporary crab spider. Next stop: A horseshoe crab, and a horseshoe!)

Once Oktar's dealt with his little legal problem, though, I presume he'll issue a flurry of lawsuits demanding that every site that's discussed this tragically hilarious story also be blocked in Turkey.

Sooner or later, Turkish Web browsers will only let you see harunyahya.com and discovery.org.

Posted in Religion, Science, Strange Tales. 6 Comments »

A rare recantation

2 October 2008 — dan

A reader brought New Zealand company "Octafuel" to my attention. As I write this, the Octafuel Web site contains nothing but a press release admitting that "on-demand hydrogen generator technology" - which is either injecting a little electrolytically-generated hydrogen into your fuel-air mixture to allegedly greatly increase engine efficiency or, according to countless dodgy Web sites, a full-blown "Run Your Car On Water!" system - is indeed worthless.

What a surprise.

Octafuel do, however, stick to their previous statement that "there are a number of international studies supporting" the idea that these generators work.

It is my considered opinion that if you set your plausibility-of-evidence bar low enough to believe that trickling a little electrolytically-generated hydrogen into the fuel/air stream will have any significant effect on anything - here's a decent starting point for exploring what evidence there is - then you must also believe that people bouncing around on their bottoms are flying, that people who allegedly have psychokinetic powers that never manifest when someone's looking at them aren't just cheating, that stickers can improve battery performance, and that magnets make wine taste better.

Apparently Octafuel issued this press release shortly before one Eric Otoka was going to have this piece published in the Waitako Times, detailing the results of his month-long test of the system. Otoka concluded that the Octafuel device achieved "a maximum of only 4.8 per cent fuel savings", which suggests to me that the error margin of his testing technique was 5% or more.

Octafuel was "'absolutely' confident the product would save between 25 and 40 per cent", though, so this is still a pretty solid piece of evidence to the contrary. And Octafuel are now arranging a product recall with refunds for purchasers. This makes them about a million times more honest than the average fuel-saver outfit.

Octafuel are behaving so unexpectedly honourably because they are not an outright scam organisation like Firepower. They actually offer some fuel-saving devices that do not blatantly defy any laws of physics. (Or, at least, they've talked in the past about offering such devices. There's nothing on their Web site but the press release at the moment.)

Octafuel apparently have a bolt-on regenerative braking system for normal cars, for instance. I've no idea how their one is supposed to work, but I've seen others. One type basically clamps an electric motor over each rear wheel - it's conceptually similar to smaller systems to add electric assist to bicycles. The motors work as generators when you brake, charging a relatively small battery or capacitor bank, which gives you extra drive when you accelerate again. This is pretty much useless for highway driving - the extra weight and drag are likely to eat up what small fuel savings there are - but it can give a not inconsiderable economy improvement for stop-start city driving. It also makes your car look a bit like a prototype Spinner.

Octafuel have also talked about Peltier-device heat-recovery units, which turn waste exhaust heat into electricity to take load off the car's alternator. Less alternator load means less fuel burned - though not much less, if you're not running an impressive wattage of electrical gear in your car.

Modern cars are adding more and more high-powered electrical hardware, though, and there's room for more. A good enough exhaust-heat scavenger could, for instance, deliver enough power to make an electrically-powered automotive air conditioner a more economical choice than the current type, which is belt-driven from the engine. And just harvesting heat from the exhaust - rather than, say, making exhaust gases directly turn a turbine - won't affect the power or economy of the engine itself at all.

Major car manufacturers have been researching this for some years. It's possible that the miserable efficiency and not-so-great durability of Peltier electrothermal devices may make "Automotive Thermoelectric Generators" uneconomical, though. I'm delighted to say that this means it may turn out to be better to run a closed-cycle steam engine from exhaust heat!

Posted in Cars, Science. 7 Comments »

Not your everyday fuel-saving gadget

28 September 2008 — dan

"A Temple University physics professor has developed a simple device which could dramatically improve fuel efficiency as much as 20 percent", says this report on PhysOrg.com.

A couple of readers pointed the report out to me, observing that at least this one doesn't claim to be using reverse-spin antiunicorn particles, magnetising the unmagnetisable, or cracking water into hydrogen and oxygen then reacting them to somehow give more power than went in.

Next, the report turned up on Slashdot, and some more readers pointed it out to me. These readers were less complimentary.

Once again, yet again, this gadget is supposed to give "more efficient and cleaner combustion". This is apparently because the fuel's viscosity is reduced by an electric field, but it doesn't matter how the heck the "more efficient combustion" happens, because there's almost no room for improvement there.

As regular readers who've been subjected to my snowstorms of links to Tony's Guide to Fuel Saving will already know, modern engines in anything vaguely resembling a decent state of tune only fail to burn a few per cent of their fuel, at the very most.

If you're only blowing 2% of the fuel out of the exhaust valve in the first place, improving combustion can only gain you a maximum economy and/or power increase of that same 2%.

If a fuel-saver inventor bothers to address this unfortunate fact, they usually start banging on about how functionally all of the fuel might be getting burned in the engine, but their invention makes it burn faster, or more evenly, or something.

I am pleased to say that no such nonsense is being put forward by the inventors of this latest gizmo. They're streets ahead of most of the other purveyors of magnets and crystals and stickers and mothball pills, for one reason: These people are actually doing proper science. They have written up and published their research. And they're not selling anything.

You just don't see this sort of... honesty... from most mileage-gadget inventors. These guys are telling the world exactly what they did, and inviting replication of their results. This is what proper scientists always do, but it's almost unknown in the mileage-gadget world. The closest mileage-gadget people usually get is encouraging hundreds of dudes in garages to all try to finally make the first Joe Cell that actually works.

The Temple University paper is titled "Electrorheology Leads to Efficient Combustion"; it was published in Energy & Fuels, a journal of the American Chemical Society. The whole paper is available online. It's only four pages, so I read it.

I don't know whether their basic idea - that applying an electrical field to fuel actually does reduce its viscosity - is correct. They say that this definitely does work on liquids which contain suspended particles, and that the larger molecules in gasoline or diesel fuel can be regarded as (very small) suspended particles. That sounds fishy to me - molecules do not, of course, behave at all like normal visible-under-a-microscope "particles" - but the paper contains a neat graph in which a sample of diesel apparently did decrease in viscosity, from 4.6 centipoise to as little as 4.2, after electrical treatment.

(I'm assuming that they kept the fuel's temperature steady. All sorts of petroleum products become less viscous when you warm them up, and their electrical gizmo will slightly warm the fuel. But only an idiot, or scammer, would fail to control for temperature in this situation.)

If their gizmo really does reduce fuel viscosity, then it's uncontroversial that it'll also improve atomisation when the fuel's squirted out of an injector in a diesel or fuel-injected petrol engine. They tested for this anyway, and got positive results.

But now we strike a problem. Devices to improve fuel atomisation are not new. They've been around for ages. And, as Tony points out on the above-linked page, even if the fuel is a vapour when it's introduced into the combustion chamber - if it's petrol that's been pre-heated by a fuel-saving gizmo, or if the engine's running on LPG or CNG - there's only a very small efficiency gain, if any at all.

According to the paper, the inventors of the electrorheology viscosity doodad tested it on a diesel engine in a lab for a whole week, and got readily measurable economy and power gains. Then they tested a Mercedes 300D on a dynamometer, and again got a clear improvement - though they say the power output improved from an average of "0.3677 hp" to "0.4428 hp", which suggests they've either slipped a decimal point or there's some large divisor here that I'm missing. The engine would be producing substantially more power than that even if it was only idling.

(They say, by the way, that their device ought to work just as well on petrol engines as on diesel. They've only tested it on diesel so far, though. The worthless atomisation-improvers on the market today are almost always for petrol engines.)

After that, the paper says they did "continuous road tests" on the same Mercedes and found even better improvements - 12 to almost 20% better mileage. But just driving a car around is, of course, not a proper test. There's just no way for a person driving a car to drive it exactly the same way every day, and people can very easily unconsciously drive more gently when they're all excited about the new fuel-saving thingummy they just installed.

You could maybe get some better-than-nothing data if you blinded a driving-around test - nobody driving the car knowing whether your doodad was operating or not - but the paper doesn't say they did that.

The paper as a whole, though, looks almost entirely kosher to me. It seems that these people really did this stuff, and really got these results. The very low 300D dyno power figures concern me - they don't seem to make any sense at all - but that's the only part of the paper that looks really dodgy.

Research like this is all about replication - other people reading the paper and then performing the same experiment. This irons out the effect of errors and dishonesty, and over time leaves us with the truth, or as close to it as we can get. Anybody who wants to can duplicate the Temple University experiment; the electrifier device should be very easy to build, and it contains no exotic materials or physics-defying woo-woo components.

But it seems to me that the electrifier's claimed means of operation, at the very least, can't be right. Improving fuel atomisation just doesn't improve combustion, or anything else. Modern petrol and diesel engines already atomise fuel as well as is necessary, and burn very nearly all of it at the right time, in the right place, and at the right speed.

If this device actually does work - and it'd be fantastic if it did - it seems to me that it must be for some other reason.

UPDATE: When I first wrote this piece, I missed the end of this press release, which mentions that the new electronic viscosity device has already been "licensed" to an outfit called "Save The World Air".

STWA's current mainstay product appears to be the "MagChargR", which looks to me like an entirely straightforward magnetic "fuel saver". The Temple University researcher who's come up with the new electronic viscosity doodad appears to be involved up to his hips in STWA. This immensely reduces my opinion of him and of the value of his research. It seems clear to me now that he is actually in this for the money, even if he has published his method and results.

(The STWA test-results page, tellingly called "testimonials.htm" gives you the usual collection of hard-to-trace allegedly-independent tests to support the claims made by the company. As usual, in order to see if the tests are actually kosher you'd need, at the very least, to check with testing outfits identified only by a cryptic name {"CP Engineering", no Web site, address or phone number given}, or located in non-English-speaking countries - in this case Thailand and China. Or just believe the pretty graphs, which contain no information about their provenance at all.

I've taken plenty of time to look into this sort of stuff before, and I'm sick of it. Screw every single God-damned one of these people with their devices that'd be worth hundreds of millions of dollars a year if they actually bloody worked but which, strangely, they've never taken the time to have properly tested by contactable organisations in the countries where they do business.)

Unlike most magnetic fuel gadgets, the MagChargR goes around the carburetor or fuel-injection equivalent rather than being clamped to the fuel line. But, as has been demonstrated from the level of quantum physics up over decades, if not centuries, hydrocarbons are just as immune to magnetism no matter where you throw it at them. I'm pretty sure that magnets for every part of every engine have been marketed at one time or another. We'd probably know if they did anything (besides collect shavings in the bottom of the sump...) by now.

If the STWA device works as well as every other magnetic fuel saver anyone has ever tested, it does not work at all. This could explain why STWA was in 2002 enjoined by the Securities and Exchange Commission against making further fraudulent representations about their products and commercial prospects.

This action was resolved in the usual way: STWA settled out of court and didn't admit anything. It would appear that this event did not put a big dent in their business.

If I were selling a legitimate fuel-saving device, I would not choose to go into partnership with a company which, currently, proudly offers what looks to me exactly like an illegitimate fuel saving device.

Posted in Electricity, Science. 15 Comments »

Light-Bulbs Of DOOOOOOMMMM!

4 September 2008 — dan

Not-very-compact fluorescent lamp

I just got an image-use request from the rather interesting NowPublic news site. They wanted to use one of my pictures of my 85-watt compact fluorescent to illustrate this article, about the dangers of mercury exposure from broken compact fluorescent lamps.

As regular readers would expect, I said no, and started in on an interminable explanation of why. It got long enough that I turned it into this blog post.

Executive summary: The second you read someone saying that metallic mercury is an incredibly potent neurotoxin, you know you're looking at bullshit.

ORGANIC mercury compounds are indeed ultra-poisonous, but metallic mercury quite simply is not. It ain't good for you; there ain't no Vitamin C in there. But breathing a bit of metallic mercury vapour really is not a big deal.

And the amount of metallic mercury in a domestic CFL is tiny - only a few milligrams. And it's all likely to be in the vapour state. So if you break the bulb anywhere with remotely normal indoor ventilation levels, the vapour will just blow away, in minutes at most. You'd have to smash the bulb and immediately stick your nose into the shards and inhale to get any measurable mercury dose at all.

If there were epidemiological support for the idea then the lack of a plausible mechanism of action wouldn't matter so much, but there isn't, especially after you filter out the unsourced ravings of people who're sure that tiny mercury doses from fillings or vaccinations cause every disease under the sun.

(Fools! Don't they know it's really aspartame we should be worrying about?!)

The NowPublic piece does have a source for the idea that tiny non-chronic metallic mercury exposure is bad for humans; it's the "study of workers" mentioned at the top of the article.

That study is not, by the way, the same as the "Maine scientific study" the article mentions next, which in fact concluded that existing cleanup methods were OK.

The "study of workers" is quoted hither and yon, but usually, as in this case, without a footnote saying where and when it was actually published.

It was published in the journal "Environmental Research" in 1993; here's the abstract. The study was done by the Department of Occupational Health at Shanghai Medical University, and it concluded that exposure to 33,000 nanograms of mercury per cubic metre of air seemed to have a measurable effect on people's mental abilities, with only a very small chance that this difference was a mere fluke.

But the average duration of exposure in the Shanghai study was TEN-POINT-FOUR YEARS.

The Maine study, I remind you, considered a "short excursion" of mercury concentration above 25,000 nanograms per cubic metre, as a result of a broken CFL, to be large. It found contamination briefly reaching more than 100,000 nanograms per cubic metre was "possible", but presumably didn't actually manage to measure it, on account of the very brief duration of such contamination as the trace of mercury vapour swirled away.

Mercury vapour exposure times from a broken CFL are likely to be measured in minutes, at most. There just isn't enough mercury in a domestic fluorescent lamp to keep a significant volume of air at the Shanghai study's dosage - far above the 300ng/m^3 Maine Ambient Air Guideline - for more than a few minutes.

I mean, even if you've got five milligrams of mercury in your CFL - you probably don't, but let's say you do - then that's five million nanograms, so it can contaminate 151.5 cubic metres of air to 33,000 ng/m3. Open a window or two and a lot more air than that is likely to blow through the room in an hour (the heavy mercury vapour can also just leak out through the floorboards of a "sealed" room). I cannot imagine how someone in a normal domestic or commercial setting could manage to keep the contamination level of a room in the tens of thousands of nanograms per cubic metre level for more than a few minutes, if they've only got a few milligrams of mercury vapour to do it with.

Given that there are more than half a million minutes in a year, I think it's clear that the exposure times in the Shanghai and Maine studies are not even remotely comparable. The NowPublic article puts the results of these two studies right next to each other as if they're both talking about the same thing, and doesn't even tell readers where to find information about the studies so they can discover the imposture.

And, on top of that, the Environmental Research study was just that one study, done by Shanghai Medical University fifteen years ago. There've been many other studies of chronic low-level mercury exposure, and it's easy to find ones that conclude that it has little to no effect, even after many years. And, I repeat, years of exposure comprise hundred of thousands, and quite possibly millions, of times the mercury exposure you can get by breaking a CFL.

So right now, there does not appear to be any reason to be particularly concerned about breaking even large fluorescent tubes indoors, let alone little CFLs. And the Maine study in fact supports this conclusion, because it found that breaking CFLs cannot create the chronic exposure which the subjects of the Shanghai study had suffered.

So it would appear that the mysterious CFL Bandit is not, in fact, a menace to public safety.

Posted in Science. 27 Comments »

Miracle Juice or Alien Race?

1 September 2008 — dan

In the shadowy netherworld of multi-level marketing, a lot of people are trying to sell juice.

It isn't ordinary juice, though. You wouldn't get far trying to shift orange, apple or grape juice via the trapezoid. The same multiple commission stages that make Amway floor polish too expensive would crank the price of your juice up far past the supermarket price of similar products.

The juice the network-marketers are trying to sell is much more special. Allegedly. It's usually from one or another improbably-named tropical tree or Chinese berry, and it's supposed to be good for what ails you.

Not that the companies that make the juices will say that. Oh, no. They're all hiding behind the US Dietary Supplement Health and Education Act of 1994, a.k.a. the DSHEA, which allows makers of "nutritional supplements" to sell pretty much whatever they like, without being required to prove efficacy or safety. As long as they don't make any therapeutic claims.

The great thing about multi-level marketing, for the people behind these programs, is that they can stay clean and avoid making illegal claims about their "dietary supplements", while their desperate-for-a-buck "distributors" say all sorts of outrageous things to try to shift product. It's like the white-van speaker racket, where a company brings crappy speakers with names similar to those of real speaker companies into the country, then hands them over to the guys in the vans. And, at the end of the day, takes their (large) share of the money. The speaker importers, like the MLM "supplement" companies, take pains to point out that they can in no way be blamed for what certain bad apples among their distributor base may do to turn product into profit.

Vibe card front

Somehow, this promotional card ended up in our house. It's obviously for a US program; I think it got to us here in Australia packed into a box with an eBay purchase.

This card is perfectly representative of the basic claims made for the phalanx of MLM miracle juices. Apart from ticks for a few of the boxes on the Twenty-Five Ways to Spot Quacks and Vitamin Pushers list, there's:

* Indistinct-enough-to-be-legal health claims.
* A frank statement that this miracle juice is better than all of the other miracle juices. (I'm pretty sure they all say this. It's like the Caliph whose wives were each more beautiful than the last.)
* MAKE BIG $$$MONEY$$$!!! CALL NOW!!!!

This particular juice has a strangely normal name, "Vibe". Close analysis of the better-than-everyone-else part, though, will turn up three of the big names in this field: "Xango" (I'm sorry - "XanGo"), "Goji" and "Noni".

And there's more. "Vemma" (which is allegedly based on mangosteen juice, like XanGo), "Monavie", "Zrii", "NingXia" and "eXfuze". And probably more; that's just all I could Google up before I got bored.

All of these juices are probably better, at least, than Kinoki foot pads, because they do actually have some nutritive value. But the reason why they're supposed to be worth more per bottle than quite fancy wine is that they're all allegedly made from "superfruits". Those are edible (in some cases only technically...) fruits or berries with unusually high "ORAC" scores.

The proud statement that this juice is "ORAC Certified" at first, of course, caused me to think that the Respectful Insolence guy was running a little sideline in dietary supplements. But it's actually talking about "Oxygen Radical Absorption Capacity" measurement. In this case, from "Brunswick Labs".

Surprisingly enough, the ORAC test is actually a real one, and it's quite possible that Brunswick Labs, despite a plethora of not-quite-medical claims on their own Web site, are quite kosher and actually doing real ORAC tests. They don't, at least, look like one of those pure quack-labs that'll analyse a sample of your hair and invariably then discover that you're in life-threatening need of whatever service is provided by the alternative practitioner who commissioned the test.

High ORAC values tell you that there are lots of antioxidants in a given foodstuff. It's common knowledge that antioxidants are terribly good for you, and especially good at slowing the aging process. There's not actually much reason to suppose that this is in fact the case, but common knowledge does not appear to care.

Result: Umpteen funny-named MLM-sold super-expensive ultra-juices that do not necessarily do anything for you that a glass of far cheaper OJ won't.

(And if you buy orange juice instead, you probably won't be endlessly pestered by whoever sold it to you to start selling it yourself, so you can get your share of the failure.)

Here's the other side of the Vibe promotional card:

Vibe card reverse

"Just ONE POTENT OUNCE OF VIBE is EQUIVALENT to nutriends** found in..."

That double-asterisk is presumably supposed to direct you to the two single-asterisk notes about Brunswick Labs ORAC testing, but neither of them explains what a "nutriend" is.

Such amazing nutrient levels don't actually necessarily sound like something you'd want, anyway. Apart from the well-established fact that taking lots of vitamins generally just gives you very expensive wee, one ounce of this stuff is supposed to give you "11 tomatoes worth of vitamin A".

One medium whole tomato should give you 20 per cent of your daily Vitamin A requirement. So slurping down tons more of that vitamin may give you something in common with Douglas Mawson.

(The juice-pushers will, of course, tell you that the Recommended Daily Allowances for vitamins are far too low. I refer you, once more, to the Twenty-Five Ways.)

And then there's "30 broccoli". 30 broccoli whats? The tiny little florets? 30 stalks from ground level up? 30 pounds?

And "Certified Organic Aloe Vera Gel", quantity not specified. But since I don't think anybody's ever demonstrated aloe to have any particular nutritional constituents that can't be found in greater concentrations in something that doesn't taste nearly as horrible, I presume a little goes a long way.

And so on.

But don't worry - even though it's so darn packed with nutrients, drinking Vibe will somehow make you thinner... on account of how "energized" you'll be!

("More energy" would appear one of those just-fuzzy-enough claims that "supplement" companies love to toss around. Searching Google for "more energy" juice mlm currently turns up well over 10,000 hits. Some of these MLM-ed supplements are packed to the gills with caffeine and not-necessarily-legal-any-more ephedra, of course, but I doubt that's the case for most of the super-juices.)

It's the names of all these miracle juices that really get to me, though.

Xango! Zrii! Goji! Vemma!

Someone should make a "Multilevel-Marketed Miracle Juice or Star Trek Alien Race?" page, like the "Porn Star or My Little Pony?" one.

Posted in Scams, Science. 4 Comments »
« Older posts
Newer posts »