Once again, why not try caustic soda?

20 January 2012 — dan

A reader writes:

One of the many things wasting space in my brain is that cocaine is commonly cut with baby laxative.

The only evidence I can remember for this is 1980s action movies, though, so I could be wrong.

Presuming they actually do that, or did that... why? Baby laxative? Could you guys not find any cornflour, or something?

Eldon

The idea of cutting a drug - or adulterating-for-profit any number of other products, for that matter - is to bulk it out to increase your income, without making it obvious that you're bulking it out to increase your income.

So you can get away with a little watering-down of booze, or considerably more if you're selling freezing flavourless lager to people who are already drunk. (Whenever it's this easy to run a scam, you can bet on centuries of merciless effort on the part of opposing lawmen. You don't mess with the weights and measures people if you know what's good for you.)

You, presuming you're a seller of illegal drugs, could also get away with mildly moistening marijuana to increase its weight.

But you couldn't get away with mixing all your whiskey half-and-half with water; even if you're the only saloon in a one-horse town, you'll soon be finding rattlesnakes in your bed. A similar trick done with marijuana and oregano is similarly inadvisable.

To the eye, the Expensive Serious White-Powder Drugs all look much the same. If you're shooting a movie and need "heroin" or "cocaine", then glucose powder or bicarbonate of soda or, as you say, flour, could do the job. But they wouldn't pass muster for a second if properly tested - just taste would give away more than very slight cutting of real heroin or cocaine with sugar or bicarb, and non-soluble substances like flour in a drug that's supposed to be cooked up into a liquid or free base may also make themselves obvious before you've gotten away to a safe distance with the customer's money.

What you, the go-getting narcotics entrepreneur who likes his knees unbroken, want instead of these mere visual substitutes is something that looks, feels, tastes, smells and behaves as much as possible like the real thing. Whatever someone does with the drug you're selling, your cutting substance should do too, at least up until the final "actually getting high" test.

Oh, and the cutting substance also needs to be as inexpensive as possible, and preferably also not poisonous.

So this is how we ended up with odd products being used to cut drugs. The famous "baby laxative" is mannitol, a pleasingly harmless substance which probably won't even give a user the runs. You need to swallow tens of grams for it to have that effect; "swallowing" via your nose will presumably work, but you'll need to be someone very big in the advertising industry, or David Bowie in the mid-Seventies, to achieve the necessary volume.

(Freebasing ought to avoid the problem altogether, but has other risks.)

Another weird-but-surprisingly-common drug adulterant is levamisole, a compound whose primary legitimate use is as worming pills for animals and humans. Levamisole looks just like pure cocaine, doesn't show up in quick-and-dirty adulterant-detecting tests, and may be a little bit toxic to heavy users, but is largely harmless. It's therefore an immensely popular cocaine-cutting agent.

There are also old-wives'-tale drug adulterants. They're putting heroin in the marijuana these days, you know! And in ecstasy, too!

No, they aren't.

Well, OK, maybe at some point someone did this. There ain't no intelligence test to be a drug dealer. But adding a very expensive drug to a less expensive drug and then selling the result as if it was all the less expensive drug is not a good business model. Marijuana dipped in PCP costs more. (Though Dave doesn't need to know.)

The heroin-in-ecstasy thing may have arisen because there is a common practice of cutting relatively expensive MDMA with a relatively inexpensive amphetamine-family drug; the two go together pretty well, since straight MDMA has stimulant effects too. Then, if someone who's used to MDMA pills full of speed gets some that have little or no speed, they'll feel much less stimulated and say there must be some opiates in these new pills.

There's one more kind of drug adulterant, which I think reached its fullest flower in the Prohibition period in the USA. Once the drug you're selling becomes illegal no matter how much care you take in making it, you see, you might as well put any old crap in it, if it meets the above criteria of not being obvious or killing your customers too quickly. In Prohibition, this explained all of the booze with methanol, and worse, in it.

It's quite easy to make moonshine that has very little methanol in it. Hell, if you start with sugar and bread yeast and keep your equipment clean, your brew will never have any methanol in it at all.

But methanol gets you drunk just as good as ethanol. And during Prohibition, the kick a given bathtub gin had was one of its most important selling points. And ethanol is an antidote to methanol poisoning; it's amazing how long serious alcoholics can survive, and not even go blind, drinking contaminated booze, as long as the good alcohol significantly outweighs the bad.

Result: Methanol-contaminated booze, often deliberately made that way by cutting it with industrial wood alcohol. It was all over the damn place, making money for gangsters and slowly poisoning large numbers of people who just wanted to get peacefully drunk.

And it got even worse. There are other substances which, superficially, get you drunk. A chemical called tricresyl phosphate is one of them. Back in the Twenties, some geniuses figured this out, observed that exposure to modest amounts of tricresyl phosphate did not seem to cause people to drop dead, and started adulterating a patent medicine called Jamaica ginger with it.

Patent medicines loaded up with alcohol were a popular way to sneak around Prohibition, and the poorer end of the market, once again, naturally gravitated toward whatever cost the least and hit the hardest. Thanks to tricresyl phosphate, Jamaica ginger or "Jake" looked like a value winner.

And tens of thousands of people were, to a greater or lesser extent, crippled.

Hooray for prohibition!

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science, Strange Tales. 7 Comments »

Short-stopping

19 January 2012 — dan

A reader writes:

When I release the trigger on my old AEG power drill (so old that it's from when a power tool was an INVESTMENT), the motor takes at least a second to spin down to stationary.

When I release the trigger on my Black and Decker cordless drill, though, the chuck stops spinning instantly.

Why the difference? Is there a mechanical brake in there? Is this some sort of regenerative braking to keep the battery charged for longer? Is there just a lot of friction in the drill because they don't make them like they used to?

Timothy

Old-style power drills have a simple design, in which the trigger connects mains power to the drill motor, releasing the trigger disconnects the power, and if you want more than one speed you can maybe move a clunky slider to change between two gear ratios and count yourself lucky because in my day laddie we used to have a bit and brace made frae whalebone wi' a sandstone chuck, et cetera.

Most modern corded power drills have a proportional speed-control system, where the further you pull the trigger, the faster the motor spins. When you release the trigger with the drill spinning, though, the motor will still take its time spinning down, unless of course there's a source of outside friction like a bit in the chuck that's still sticking through a piece of wood.

This spin-down behaviour is natural for almost all rotary electric motors. If you don't count certain odd birds like stepper motors, any spinning electric motor will, when you disconnect the power, coast down to a halt.

Except, as you say, cordless drills always stop at pretty much the exact moment you release the trigger, as long as you're not spinning some large object with the drill, like a hole-saw or sanding drum. And even then, they stop pretty quickly.

The reason for this is that cordless drills use simple, inexpensive brushed DC motors. (Actually, brushless motors are starting to show up in fancy cordless tools, but I'll shamelessly handwave that awkward fact for the purposes of the current conversation.)

Brush motors are really easy to stop dead: You just short out the input terminals.

If you've got a bare DC motor sitting around somewhere - I'll wait, while you dig up your box of old radio-controlled car parts or smash open that useless bloody $5 electric screwdriver that the batteries never even properly fit into - you can demonstrate this for yourself. Spin the motor's spindle by hand, and then short the terminals on the back of the motor with a paper clip or something and spin the spindle again. In the second situation, the faster the spindle spins, the greater the braking power on it.

The reason for this is "back EMF", a special case of the counter-electromotive force which, in brief, causes the currents induced in a piece of metal by a magnetic field to create another magnetic field opposing the first one. You can make an "eddy current brake" that employs this force to convert motive power directly into heat in the brake assembly, without any friction; this is useful in everything from heavy industrial applications to the delicate aluminium-paddle magnetic brake that sticks out of the side of a laboratory balance, whose purpose is to stop the darn scales from swinging back and forth around the correct reading until the research project runs out of funding.

In brushed DC motors, back-EMF braking works really well, which is why it is, for instance, the normal braking system for the abovementioned electric radio-controlled cars. A fast-stopping drill is a desirable thing to have, too, so releasing the trigger disconnects the power from the motor, and shorts the terminals to each other. There's no simple way to do the same thing in an AC motor, so you don't get this feature in corded drills.

Back-EMF braking won't instantly stop a motor if it's turning fast enough. I've got a Dremel Stylus, for instance, which is a brilliant little tool for all of those jobs for which my old mains-powered Dremel is a bit too powerful and clumsy, but for which a cheap AA-powered Dremel or similar suspiciously inexpensive rotary tool would be too feeble. I think the Stylus has a simple brush motor in there (as you change its speed, it sings the distinctive song of a brush motor vibrating because of audio-frequency pulse-width modulated speed adjustment), but its top speed, as with all rotary multi-tools, is much higher than the top speed of a cordless drill. So when you turn the Stylus off, it stops pretty darn quickly, and quite a bit quicker than the mains-powered Dremel, but it still takes about a second to run down.

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Electricity, Psycho Science, Science. 3 Comments »

A grilled 4-hydroxyphenethylamine sandwich

18 January 2012 — dan

A reader writes:

When I eat cheese, I sweat. I don't really feel hot, I just break out in a sweat.

Sweating when you eat a curry, that I understand. Or a big hot dinner; that could actually physically heat you up. But cheese? WTF?

Don

There's a compound in aged cheese, tyramine, that induces the release of epinephrine (a.k.a. adrenaline), and some related neurotransmitters. The result is a sort of mini-fight-or-flight reaction, including a faster heartbeat and, as you say, sweating.

Tyramine affects different people differently; many people don't notice the effect at all. I think the effect can vary from day to day and depending on how much cheese you've eaten. It does for me, anyway; sometimes vintage cheddar gives me a cheese-sweat, sometimes it doesn't.

Speaking of which, the type of cheese definitely matters. Un-aged cheeses, like cream cheese or cottage cheese or Kraft Reprocessed 580-Nanometer Partially Homologated Polymer Dairy Analogue, contain very little tyramine. As a general rule, the stronger-flavoured the cheese, the more tyramine there'll be.

It's the tyramine, by the way, that makes it a bad idea to consume vintage cheese if you're also taking a monoamine oxidase inhibitor drug. Old-style "irreversible" MAOIs plot to kill you in a few different ways, one of which is giving you a massive blood-pressure spike if, in cheerful defiance of the common sense of more than half of the world's population, you eat something which used to be milk, but has been left to sit for years on end and is now a stinking mould-covered lump of obviously lethal putrescence.

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science. 2 Comments »

Please at least pay us for the postage

17 January 2012 — dan

A reader writes:

I don't know if this really qualifies as a science question, but: How do bills for zero dollars and zero cents get sent to people?

I'm guessing that it's something like the process you explained that leads to crazy negative numbers in installer disk-space calculations - maybe the system's screwed up and thinks you owe negative money (or you really do, because you overpaid), but there's a sanity check that rounds negative numbers to zero, and then fails to stop a bill being sent anyway.

Am I right?

Jiri

Exactly this sort of thing has been referred to since time immemorial, or at least since the early days of office automation...

...as a "computer error".

Which it isn't, of course. Once in a very long while a cosmic-ray strike or failing power supply or actual hardware defect does really cause a computer to make an error, but the overwhelming majority of "computer errors" are actually programmer errors. The computer is doing exactly what it was told to do, whether that's sending a bill for $0.00, or charging a startled pensioner for a hundred million kilowatt-hours of electricity, or falsely saying an e-mail came from FinkyPieheimer@zoobatz.com.

One programming error that can lead to a zero dollar bill - and, in due course, to second requests and final demands and then the attention of lawyers, if only because the lawyers are happy to round the ten seconds needed to recognise the mistake up to about ten billable hours - is using the wrong kind of variable.

In the real world, money comes in dollars and cents, pounds and pennies, rupees and extremely un-valuable paise, and so on. There's no such thing as a fraction-of-a-cent coin.

In computers, everything can be chopped up into arbitrarily small pieces, if necessary. There may be some good reason to do this for certain calculations applied to currency amounts (though I can't think of one), but if you do, before any of the results get turned into actual money being paid into accounts or demanded from clients, the numbers should be rounded into an integer number of cents (or whatever other currency unit's being dealt with).

(This process can be exploited, in the classic "salami slicing" scam where a great many fractions of a cent are sneakily diverted to the scammer's account by, for instance, always rounding down, even when the fraction being rounded is larger than 0.5.)

If a programmer uses, say, a single-precision floating-point variable to hold a monetary value, it's easy for the limited precision of the variable to, when mathematical operations are performed on it, end up at 0.9999 (probably with a few more digits) instead of 1, or 0.0001 instead of zero. In the latter case, a system that doesn't round off the imprecise value to what it should be, and subsequently starts the billing process on any account where the amount owing is greater than zero, will send idiotic zero-bills to customers.

(Or the only slightly less stupid version, a bill for an amount less than what the company paid to post the bill to you.)

There are many other ways for this to happen, though, thanks to the many ways in which programmers can make a mistake. A billing system could, for instance, fail to notice previous overpayment, decide to send a bill, then apply the overpayment to the account balance and send a bill for the net amount, which could be zero or negative. Or it could decide to send a bill to a customer who legitimately owes money, and then accidentally print the amount that some other, fully paid-up, customer owes on the bill.

Just because a company's got thousands of employees and annual turnover greater than the whole economy of some nations does not preclude this from happening. As Daily WTF readers know, staggeringly expensive "enterprise" software can be very, very badly written.

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Money, Psycho Science. 9 Comments »

There's nothing like a nice caustic soda facial scrub

16 January 2012 — dan

A reader writes:

What's the chemical difference between soap and detergent? I know soap's made by reacting an oily substance and an alkali; is detergent made some other way?

Jun

Soap is, as you say, a class of substances with a clear chemical definition; a soap is a salt of a fatty acid. Soap molecules, in brief, are hydrophilic on one end and lipophilic on the other, and so allow oils to disperse in water.

Detergents are less clearly defined. One old definition of "detergent" says it's just any substance you use to clean something. By that definition, plain water is the most common detergent, and soap is detergent too. Sand counts as a detergent by this definition, because you can scour pots with it.

The standard home-and-garden definition of a detergent is, of course, much more limited; it covers dishwashing liquid, dishwasher powder, laundry liquid and powder, and so on. Any consumable cleaning substance that doesn't come in a solid bar, or in a pump-pack with "Soap" written on it somewhere.

These detergents contain one or more surfactants that do something similar to what soap does - often the ubiquitous sodium lauryl and/or laureth sulfate, which are not actually incredibly good at cleaning, but are very good at making the rich bubbly lather that consumers have been trained to equate with cleaning power. On top of that, there's "builders" that make the surfactant work better, and various other substances suited to the application. Oh, and in the case of liquid detergents, there's also quite a lot of water, which I've heard referred to by a formulator of shampoo and conditioner as "profitrol".

There are lots of substances that, like plain water, can fill the role of a detergent without containing surfactants. Sodium carbonate or bicarbonate, for instance, can be used as a fairly effective remover of oily substances all by themselves, essentially because they're alkaline and make a little of their own soap from whatever oils are on the thing to be cleaned. Sodium carbonate and bicarbonate are, however, not alkaline enough to be dangerous (unlike the standard soap-making alkali, sodium hydroxide), and also quite non-toxic, so you can use them straight as dishwasher powder with decent results if you're out of the detergent-y stuff.

(Note that some non-standard cleaning products actually have little or no effect at all. The classic example is the magical plastic laundry ball, which doesn't actually do anything, but may appear to work without any other detergent because plain detergent-less water will clean your clothes to some extent all by itself. See also, stone soup.)

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science. 4 Comments »

Why black powder isn't, or is

13 January 2012 — dan

A reader writes:

Why is "black powder" gray when I make it, but black when I buy it?

I live in the Land of the Free and the Home of the Well-Regulated Militia and can buy gunpowder over the counter to, uh, use in my collection of historic muzzle-loading muskets, Officer. The stuff you buy, though (and the stuff I've seen on Mythbusters too, actually) is sort of shiny black, in various different particle sizes depending on burn rate and whatnot.

But when I MADE gunpowder as a kid, the recipe was three-quarters saltpeter, and saltpeter looks like salt. It's white. So the powder comes out pale gray.

What gives?

Steven

As you say, the recipe for standard black powder for firearms is 75% potassium nitrate, 15% charcoal and 10% sulfur, by weight. And this does indeed create a grey powder, not a black one. Everything associated with making and combusting black powder tends to end up pretty darn black, thanks to the charcoal in the mix and the copious smoke and other solid residue created by the powder's inefficient combustion, but the powder itself isn't black.

Commercial black powder looks black because the little lumps of the stuff are coated with graphite. In the manufacturing process, the powder's mixed with water or some other liquid binder, pressed into cakes and dried, then crushed and screened into powders of various particle size, larger particles producing a slower burn. The graphite serves no chemical purpose, but it lubricates the particles, and also makes the bulk powder electrically conductive enough that it's unlikely to initiate proceedings unexpectedly because of a static-electricity spark.

(You can't, by the way, make decent black powder using graphite, or any other high-purity carbon, in place of charcoal, because the leftover wood impurities in charcoal make it ignite at a lower temperature. Pure carbon makes a black powder that burns slowly; it might eventually push a bullet out of a rifle's muzzle.)

Black powder remains a somewhat excitable substance, even with graphite on it; it is, for instance, still pretty impact-sensitive, if not by the standards of substances of which only lunatics prepare more than a gram.

It's now apparently becoming harder to find black powder even in the gun-happiest parts of the USA; instead, there are various black-powder substitutes. All of the substitutes are safer than black powder, and many of them have other benefits, like not fouling your muzzle-loader with corrosive sulfur compounds.

Psycho Science, as I have brilliantly decided to call it, is a new regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science. 5 Comments »

Hanging your husband

12 January 2012 — dan

A reader writes:

How is it possible that I can belay my husband when rock climbing? He is almost twice my weight.

At our local climbing gym, the top of the "cliff" has a cylinder, which the climbing rope is thrown over, wrapped around, and falls down off the other side (i.e., it's touching 540° of the cylinder). The employees say that it works because the rope is wrapped around the cylinder twice. I'd like a more scientific explanation, though: does wrapping it actually increase the amount I can lift? Is it just friction?

As another data point, I belayed him once on an incorrectly-set-up wall where the rope was only thrown over the cylinder, not wrapped around it. I felt alarmingly weightless when supporting my husband's weight, but my feet stayed on the ground.

Kristina

Yes, belaying really is pretty much all about friction.

When you wrap a rope around an object a few times and pull on both ends, there's enormous friction between the rope and the object, even if the object's smooth. If the tension on one end of the rope, plus the friction, exceeds the tension on the other end, nothing moves (the exact numbers can be calculated using the "capstan equation"). So you can belay your husband. Actually, with enough turns around the cylinder and assuming the cylinder and the rope are strong enough, you could belay anything at all. (Getting a grand piano, a garbage truck, the USS Nimitz or the planet Mercury into the climbing gym is left as an exercise for the reader.)

When either end of the line is slack, which is the case most of the time, almost all of the friction disappears and it's easy for the climber to proceed upward while the belayer takes up the slack.

What you can't do, of course, is actually lift whatever's on the other end of the belaying line. Trying to do that puts you on the wrong end of the equation; you'd have to pull with a force greater than the mass on the other end of the line, plus the friction, which gets worse the harder you pull. In this situation, with a few turns around the cylinder, the world's strongest man would be unable to hoist a small child. If you add another, movable smooth cylinder, though, or preferably an actual pulley, you can make a block and tackle and lift arbitrarily large loads by applying a smaller force over a longer distance.

Standard yachting capstans (the things that you are apparently legally required to see people frantically cranking whenever TV news reports on a yacht race) are pretty interesting, too. They contain a planetary gearset that only operates when the capstan's being turned in one direction. Turn the capstan crank that way, and the gearset turns the outer barrel of the capstan at a fraction of the speed at which you turn the crank, making it possible to apply a strong pull to a line under tension. Turn the capstan the other way, though, and the gears lock up and connect the barrel directly to the crank, allowing you to let the rope out again quickly.

(Well, that's the way the old one depicted in one of my favourite toilet books worked, anyway. I'm sure there are now also capstans that can turn the barrel faster than the crank. They probably have infinitely variable transmissions in them by now.)

Psycho Science, as I have brilliantly decided to call it, is a new regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science. 7 Comments »

Spun out

11 January 2012 — dan

A reader writes:

Is it possible to spin an object with two axes of rotation from just one initial impulse?

Specifically the question is about spinning a cricket ball.

If we take the X axis to be running between the wickets, Y to be the other horizontal axis, and Z to be vertical; spin bowlers generally spin the ball on a single axis somewhere between X and Y, depending on whether it's a break or a top-spinner. But, would it not also be possible to spin the ball simultaneously on the X and Z axes, so that it would be virtually impossible to tell which way the ball will turn until it lands? It would start off spinning on Z and X, but as it rotates about the Z axis the other axis of rotation would change.

I've been attempting to do this but it does not seem to work. The ball only seems to take one axis. I'm wondering if it's not actually possible to do it with just one spin, and it would require an initial spin followed by a separate impact?

James

Not only is it not possible to spin an object with two axes of rotation from just one initial impulse, but it's not possible for a rigid body to revolve simultaneously about more than one axis, at all, per Euler's rotation theorem. If a rigid body is spinning around an axis you call X, and you apply a force to it that, were it motionless, would cause it to start spinning around an axis you call Y that's at right angles to X, you'll end up with it spinning about some single axis between the two, the axis and speed of rotation being determined by the forces that've acted on the object.

An ongoing force acting on a rigid object, though, can cause an ongoing change in its axis of rotation. The axis will always pass through the object's centre of gravity, but it can be moved around in numerous ways.

In the case of a cricket ball, the axis of rotation can change slowly as a result of aerodynamic forces - which can also push the ball off the perfect ballistic trajectory it'd have if there were no air - and suddenly when the ball bounces off the ground, as it usually does in cricket.

(In an interesting piece of US/Commonwealth parallel evolution, cricket balls and baseballs are actually extremely similar in size, mass and construction. Apart from colour, the principal difference between the two is that a cricket ball has "equator" stitching while a baseball is made from two saddle-shaped pieces of leather, and the cricket ball has a harder surface. Cricket balls are also generally bowled somewhat slower than baseballs are pitched, and lose some momentum when they bounce off the ground. This lamentable reduction in lethal potential is, thankfully, largely compensated for by the cricket ball's harder surface and the bowler's ability to bounce it right up into the batsman's chin at ninety miles an hour.)

There are many other situations in which a spinning object can appear to have more than one axis of rotation, but they're all the result of forces acting on the object. A flying ball experiences aerodynamic forces, a billiard ball skids across the table with a spin different from its direction of travel, a comet is pushed around by gas from its own melting ice, a gyroscope precesses because of the pull of gravity, the wobble ("nutation") of the Earth's axis is the result of tidal forces from the moon and sun, and so on.

Regarding your own bowling experiments: Sorry, but you cannae change the laws o' physics. Even if you cheat, the ball's still only going to have one axis of rotation at a time, and that axis is only going to change in response to aerodynamics and hitting the ground.

Psycho Science, as I have brilliantly decided to call it, is a new regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.

Posted in Psycho Science, Science. 2 Comments »
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