Too big to believe

Sorry about not writing anything for ten thousand years. I started writing a book. I'm not very good at it.

Apropos of nothing, the other day it occurred to me, as I am sure it has occurred to many other people, that there's a parallel concept to the Big Lie.

A Big Lie is a lie so audacious that people can't believe you're not telling the truth. If nobody can believe that you would just make up reasons to exterminate a significant percentage of the population of Europe, or found a religion entirely upon stuff you pulled out of your arse, or throw trillions of dollars down the toilet in the pursuit of imaginary terrorists, then you can be successful in such ventures.

(Hitler of course said the Big Liars were in fact the Jews, who he went on to explain were to be expected to lie about everything all the time. This would make it a little odd that anybody believed their lies, regardless of size, but never mind. Water under the bridge, old chap. Some credit is deserved for anybody whose own Big Lie is an accusation that someone else has told a Big Lie.)

What occurred to me the other day is that there's a converse to the Big Lie: The Big Truth.

A Big Truth is a truthful statement with such vast and terrifying implications that people refuse to believe it.

There's a term for the logical fallacy of disbelieving something because its implications are unpalatable, the "argument from adverse consequences" or just "appeal to consequences". "God must exist, because if he doesn't then I will not be able to live forever." A Big Truth is a very large and shiny example of this fallacy. (And, as for believing a Big Lie, it's not necessary that everybody disbelieve a Big Truth, only that people disbelieve it purely because of the largeness of the disturbance to their world that would occur if they believed it.)

A few Big Truths that spring to mind:

Illegal drugs are less harmful than legal ones.

The consequences of a lifelong addiction to clean heroin, in and of itself, are: Constipation. You're also better off getting your stimulation from amphetamines instead of caffeine. Arguments against this are generally of the form "if you take way too much of that drug and don't eat right and never get any exercise then you'll be very ill", which can of course be said of alcohol, tobacco and even caffeine. (And sugar, for that matter, though it's not a drug.)

Many leaders of the free world are by their own admission guilty of crimes for which the punishment is death.

The first and worse of all war crimes is the crime against peace, the starting of a war of aggression, because that's the one that makes all of the other war crimes possible. (Inevitable, even, because there's never been a war of any size in which some combatants didn't take the chance to have some war-crimey fun.)

Lying about your enemy and saying they are lunatics who attack their own people and have terrible weapons pointed at us and really it's them that are starting the war et cetera does not get you off the hook, because that's how everybody starts a war of aggression in a "free" society. But everybody knows Dubya and Cheney and Rumsfeld and their minor lickspittle Blair and extremely minor lickspittle Howard will never see the inside of a courtroom over this.

Climate change is happening, even if there are leaflets and novels with the author name bigger than the title that say it isn't.

Oh, and gods do not exist.

What Big Truths can you think of, readers?


A reader writes:

I was watching an awesome Honda ad featuring the ghost of Ayrton Senna and his 1989 car...

...and I noticed people arguing in the comments on Jalopnik about Doppler effect, which I think you can hear in the video as the "car" goes past the camera.

Per your previous writing about "common sense" and concepts that "slither out of people's mental grasp", can a series of speakers set up around a racetrack and playing the sound of a car actually create the same Doppler effect as the actual car did?


No, they can't.

The Doppler effect happens when a moving object emits something, in this case sound waves. When each new wave is emitted in front of the sound source, it's closer to the previous wave than it would have been if the emitter were stationary. Behind the emitter, each new wave is a bit further from its predecessor than it would be if the emitter weren't moving.

This works for light as well, hence "redshift" and "blueshift".

We don't notice redshift or blueshift in everyday life because Doppler shift is a proportional effect, and the speed of light is so high that no light-emitter that humans normally deal with moves at an appreciable fraction of lightspeed relative to us. The speed of sound, however, is relatively low (about 340 metres per second close to standard temperature and pressure), and the human ear is quite sensitive to changes in pitch. So we can easily hear this effect on the sound of a car engine...

...or horn, when that car passes us at speed.

(My favourite example of car-horn Doppler shifting, which includes a lot of moderately comprehensible cursing, is this one.)

If you set up a bunch of speakers to imitate the sound of a passing car, none of them are moving, so there will be no Doppler shift from the point of view of a stationary observer. You could create the same effect by deliberately adding pitch shifts to the sound being played so that it sounds correct from a given listening location, but that'll make it sound wrong to listeners somewhere else. Doppler changes are caused by waves being bunched up and spread out by motion, and that just doesn't happen if neither listener not sound-emitter are moving. There's nothing about the order in which speakers play sounds that change what the sounds are.

(OK, there might be some interference effects audible at various listener locations. But that wouldn't sound Doppler-y.)

There actually would be Doppler effects if you were in your own car driving around the racetrack during the ghost-of-Senna performance, though. A moving listener creates Doppler shift in exactly the same way as a moving source:

Again, though, the pitch-shifts wouldn't sound right. They'd entirely depend on your speed relative to whatever stationary speakers are sounding at a given moment.

A related concept to this is the idea of the faster-than-light laser dot.

Consider flicking the dot of a laser pointer across, say, the face of the moon. (Presume you've got a laser that's well enough collimated that it still has a small dot at that distance.)

If the dot crosses the moon in, say, a hundredth of a second, and even if you ignore its curvature the moon is about 3,400 kilometres across, then that dot is going about 340,000 kilometres per second, which is faster than light. Address for delivery of Nobel Prize in Physics will be provided on request.

Unfortunately, and to the chagrin of a great many cats, a laser dot is not a "thing". It's just where photons happen to be falling and bouncing off at any given moment. Moving a dot faster than light is indeed perfectly theoretically possible, but you might as well give two blokes each a flashlight with an accurate timer built in, have them synchronise timers and then move a thousand kilometres apart, and then turn their flashlights on and off so that one light-pulse happens a thousandth of a second before the other. Presto, now a dot has moved at a million kilometres per second, more than three times the speed of light!

Except that doesn't mean anything, because that dot of light is not a thing moving faster than light. You could fill the space between those two flashlights with a trillion more flashlights timed to give a wonderfully smooth movement of the dot, but the dot would still not be a thing travelling faster than light. A spinning lawn sprinkler may have a contact point between droplets of water and the circumference of its spray pattern that goes round and round at a quite impressive speed, but that's just where the water hits the lawn, it's not an actual separate moving object.

(By the way, smart alecks, relativistic time dilation does not mean the flashlight timers would get significantly out of sync if the flashlight-carrier on one end got to his assigned location on foot, taking weeks, and the other got to his by rocket-sled at ten thousand kilometres per hour. At 10,000km/h your clock will tick slower than that of a stationary observer, but only by a factor of 1.0000000000429. The fastest object humanity has ever made is the Helios 2 probe, at 70,220 metres per second relative to the sun; it achieved a time dilation factor all the way up at 1.000000027!)

A further extension of this idea is to say, "OK, what if I've got a stick a million kilometres long, and I hold one end of it and spin it around my head in a circle in, say, five seconds? The circumference of a circle with radius one million kilometres is 6,283,185 kilometres, and the tip of the stick it will go all the way around that circumference in five seconds, which is 1,256,637 kilometres per second. The tip of the stick is a thing and not just a dot of light, so it's really going at that speed, which is 4.2 times the speed of light, NOW can I have my Nobel prize?"

No, you still can't.

Ignoring the obvious issues regarding the construction and inertia of a million-kilometre broomstick, there is no way for one end of an object to know what's happening to the other end at faster than the speed of light. Motion of the object occurs when the molecular bonds that hold it together are stretched and pull the molecules along, and there's nothing about those molecular bonds that causes them to influence each other faster than light. Otherwise you could make an instantaneous communication system by taking your very long magic broomstick and tapping on the end of it in Morse code or something.

So even if your very long stick were made of alien indestructium with an infinite tensile strength, spinning the middle of it round and round would just cause the whole thing to start wrapping up into a spiral. You could then try cracking it like a whip if you wanted, because you're Cowboy Galactus or something, but the other end of the object would still not travel faster than light, because no "information" within the object, in this case the information regarding the location and motion of its component particles, can travel faster than light either.

This seems bizarre, but again this is because we're talking about scales far larger than those on which humans normally operate. On the very large scale, nothing is particularly solid. If planets and stars and even galaxies run into each other, the energies involved may be unimaginably large, but all of the actual objects behave pretty much as if they were made of blancmange.

(Actually, in galaxy collisions, few to no actual collisions of the objects that make up the galaxies are likely to happen, because galaxies are mostly empty space.)

If Unicron were actually the size of even a small planet, no material that even theoretically exists in the universe would be stiff enough for him to be able to transform like his car-sized distant relatives. (Well, maybe if he's made of some kind of degenerate matter and has magical technology to prevent himself from collapsing into a black hole. Once you can cancel gravity, you might as well move information faster than light, too. It never seems to take a Transformer or Decepticon much more than twenty minutes to get to anywhere in the universe, after all.)

To reward anybody who managed to get to the end of this post, the ghost-of-Senna ad sounds pretty good, but the Shell-Ferrari one from a few years ago is much better:

(I think that version's the best one on YouTube in both resolution and sound. Aspect ratio's wrong, though.)

Psycho Science is a... sort of... 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.

A metallurgical detective story

There are people on eBay selling "liquid metal bullion".

They don't like to tell you exactly what metal this alleged "bullion" is, except they always swear it doesn't have any mercury in it.

They generally say it's solid at room temperature, but will melt from the heat of your hands.

Those of us with a mild recreational interest in the periodic table will draw a rapid conclusion if given the characteristics "metal, melts at body-heat temperatures, doesn't explode on contact with moisture...

...and non-toxic."

That'd have to be gallium, right?

Wrong. I bought some, and it's nothing like the gallium I already own.

I didn't know what the hell the "liquid bullion" was. Not, at least, until I played around with it for a while.

Fusible metal ingot

There seems to be some sort of tradition in the hobbyist low-melting-point-alloy business of casting your little ingots in unorthodox moulds. The mould is usually something that clearly indicates that the metal was liquid at temperatures low enough that to not instantly destroy a chocolate-box tray, silicone ice-cube tray, or similarly non-refractory mould material.

Wood's metal casting

I cast my own Wood's metal in a Lego mould.

You could craftily fake this by casting wax in a chocolate tray, then using that form to make a sand mould, or something, but I don't know of any such scandals in the retail weird-metal market.

All of the low-melting-point alloys exist because of the odd fact that mixtures of chemicals can have a lower melting point than any of the ingredients.

On the face of it, this doesn't make sense. I mean, the universe should be nice and sensible and line up with the way ancient philosophers hoped it worked, from tiny billiard-ball atoms all the way up to clockwork galaxies. Then, the melting point of an alloy would be the melting point of its constituents, weighted by what proportion of the alloy each constituent took up. So for Wood's metal, for instance, you'd have:

50% bismuth, melting point 271.5°C
26.7% lead, melting point 327.46°C
13.3% tin, melting point 231.93°C
10% cadmium, melting point 321.07°C

Weighting each of those by the fraction they take up gives 135.8, 87.4, 30.8 and 32.1; add those up to get your naïve simple mathematical logical melting point and you get 286.1°C.

The melting point of Wood's metal is actually only about 70°C. Stuff like this is why metallurgy was much more art than science for a long, long time.

(In case you're wondering, which you probably aren't but I was, for these kinds of calculations it's safe to use Fahrenheit, Celsius or Kelvin temperature scales. The arbitrary zero points of Fahrenheit and Celsius don't screw it up. Beware anybody who tries to tell you that a 30°C day is "twice as hot" as a 15°C day, though, because that's so dumb as to possibly be not even wrong. 15°C is 59°F, for instance; making 59°F "twice as hot" gives you 118°F, which is 47.8°C. Kelvin starts at absolute zero, so it's the only scale in which you could actually fairly say one temperature is twice another, though I'm still not sure how useful such an observation could be. Starting at -273.15°C makes "doubling" room temperature in Kelvin rather dramatic, though; 15°C is 288.15 Kelvin, double that is 576.3 K, which is 302.85°C.)

Many alloys don't have this oddly low melting point. Brass, for instance, has a melting point from about 900 to about 940°C depending on its formulation; it's composed of copper (melting point 1085°C) and zinc (melting point 420°C). The melting point of brass is higher than you'd expect from naïve proportion calculations.

But the most common low-melting-point alloy is ordinary tin-lead solder, which exhibits the melting-point-reduction effect. Tin melts at 232°C, lead melts at 327°C, but if you mix 63% tin with 37% lead you get an alloy that melts at only 183°C.

And so, back to my "liquid bullion" ingot, which I bought on eBay Australia for $AU19.01 delivered after watching several people buy their own for prices that exceeded my modest snipe.

It was quite small. Only about four centimetres in length...

Fusible metal ingot in hand

...and it weighed more than fifty grams.

That made it dense enough that, despite the seller's claims of non-toxicity, I treated it as if it were made of solid cadmium until I could figure out the thing's composition for myself.

(The seller was this guy - possibly NSFW! - who is now out of the "liquid bullion" business, having found the whole thing to be "nothing but a headache". That "NSFW" is there because after he got out of the liquid bullion business, he sold several pornographic coins. I am not making this up. As I write this he's only selling a sofa, but I'm sure he'll offer the Internet flea market some more eyebrow-raising products in the near future.)

The listing for my "bullion" ingot gave no hints regarding its makeup, but I bought it anyway, partly because low-melting-point metals interest me. I also figured that "liquid metal bullion" might be just as entertaining as "copper bullion", with which I had a lot of fun a few years ago.

(Tl;dr: Base metals sold by the troy ounce may be a fun novelty, but are not a good investment.)

Copper-bullion sellers are still rampant on eBay, but this liquid-metal schtick is new, and extraordinary.

It is, you see, mystery bullion! An unknown metal! Usually billed as very rare and valuable and desirable, whatever it is, but available to you today for amazing prices!!1!

I saved the listing from which I bought my little ingot. I won't upload the whole page-copy here, though, because malware-detection services tend to flip out, with some justification, if they find what looks like an eBay listing on some site other than eBay.

Here's what the listing said, though, with only the eBay trimmings and images removed.

Children, avert your eyes! Just reading this may delete more than a year of science education from your brain, and make you noticeably less intelligent than you were before!

999 Pure Liquid Metal Bullion INGOT 99c A GRAM 52.6 Gram Not 1oz Silver bar Coin



You will receive 1 ONE
Ingot as pictured which weighs 52.6 GRAMS IN TOTAL. Size is (1 & 3/4" long) (1" Wide)  (1/4" High)




Purchase as many as
you like. You will only pay the quoted postage cost as I will cover any EXTRA

This metal is
considered  bullion as it is pure rare

It melts at the low
temperature of less than 30 degrees, will even melt in your hand if held long


Spot Price is
increasing at a rapid rate with the demand of this

Pure Liquid Metal

Only 99 cents per
gram and one off low postage cost of $3.00

There's... I mean...

Look, I'm not even going to start with that description. It's the sort of scientific word-salad more often seen in explanations of crackpot cancer cures.

Oh, OK, just one thing: "Rare earths", and metals which are precious for their rarity, are not the same thing, no matter what certain eBay sellers think.

The elements known as "rare earths are actually quite common; the only "rare" thing about them is their concentration in any given load of ore, meaning you need to dig up a lot of the planet to get a little bit of rare-earth element. And then it's difficult to separate the different rare earths from each other, because several of them have very similar chemical properties.

Rare-earth elements are today used to make neodymium-iron-boron magnets, hence the term "rare-earth magnet". Modern lighter "flints" are made from a very sparky, pyrophoric...

...and somewhat excitable...

...alloy of different rare earths, plus a few other things and iron for strength.

Rare-earth magnets and lighter flints are not very expensive per gram, though, because they contain no precious metals. For a few bucks you can now buy a ferrocerium stick intended for use as an emergency fire-lighter - just scrape it with a knife blade, file or similar item to create a shower of sparks.

(There are fancy versions of these things with built-in scrapers, but a simple bare ferrocerium rod is almost as good. You can get a little one with a handle, perhaps a stick of magnesium too for use as high-temperature tinder, and a bit of hacksaw blade for scraping and spark-striking, for about a dollar delivered. A chunkier bare ferrocerium rod will only set you back a few bucks from a dealer who doesn't quite know the difference between magnesium and ferrocerium, and may theoretically save your life one day. It will definitely provide you with considerable entertainment and some tiny holes burned in whatever happens to be near you when you play with it.)

The YouTube link in the above exercise in eBay creative writing goes to this video, from the brain-polluting "HouseholdHacker". That dude used to make ridiculous practical-joke "how-to" videos, which on the one hand encouraged a lot of adults to do entertainingly silly things, but on the other hand probably turned some kids off science. Which took that guy right the hell off my Christmas-card list.

Now, though, HouseholdHacker seems to be producing serious videos. The one linked to by the liquid-bullion guy isn't what you'd call packed with educational information, but the only actual inaccuracy I noted in it was incorrect rounding so the melting point of gallium was 0.1°F off. That is not exactly a capital crime.

But I still think that you're going to transition from "joke videos to get people to do stupid things" to "actually telling the truth", you shouldn't keep your old name. Mixing the two is completely uncool, man.

(Oh, and while I'm on this subject, see also my favourite example of this latter crime. Good ol' Kip deleted all of his highly remunerative Metacafe videos at some point after he reinvented himself as the video face of Make magazine, thereby ensuring that I stopped watching any of their videos. I think Make came to their senses and quietly fired him after a year or three; their videos are much better now, and they've recently started an interesting new series.)

If you want a video about low-melting-point alloys that's not from a professional bullshit artist, you could do a lot worse than turn to "Brainiac75":

Oh, and if you want a good video about gallium alone, then you obviously need to turn to actual scientists...

...and their magnificent example of an actual scientist who looks like a mad one from a horror movie.

Aaaaanyway, anybody who hasn't yet died of old age reading this page may remember that the question was... what is this "liquid bullion" stuff?

While I was sniping auctions, little fifty-gram ingots like mine kept selling for twenty-five Australian dollars or more. That's a good price for fifty grams of gallium, but it's not a good one for a similar amount of toxic low-melting-point alloy. Small amounts of anything cost more per gram, but you don't have to buy a huge amount to pay a lot less. Brainiac75 above said he paid only ten Euro cents per gram for some of the lower-melting-point alloys in his videos.

(The very lowest-melting-point alloys in Brainiac75's video are alarming concoctions like an amalgam of periodic-table neighbours mercury and thallium. That is not ten cents per gram, but it stays liquid down to -60°C. Cesium-potassium-sodium makes it down to -78°C without solidifying, but it also explodes on contact with water.)

For my first attempt at identifying the metal, I contacted the seller thusly, batting my eyelids innocently:

I've received my little ingot, and now I find myself wondering what it's actually made of. Your listing doesn't mention this, other than to say that it contains no mercury. What actually IS this alloy?

I'd also be interested to learn where to look up the "spot price" you mention in the listing. (Which again, of course, requires me to know what alloy this actually is.)


While I waited for him to reply, I measured the little ingot's density.

Accurately calculating the density of a small object is tricky. Getting a vague ballpark figure isn't hard, especially if the object is roughly a rectangular prism, as this one was. Just measure the edges, fudge any bevelled edges into a sensible-looking in-between number, and then multiply the numbers. Doing that with the little ingot gave me a volume of about 5.6 cubic centimetres. Since it was bang on its advertised mass of 52.6 grams, this gave me a density of about 9.4 grams per cubic centimetres.

The density of solid gallium is only 5.91 grams per cc, so clearly this wasn't gallium.

(Gallium is also one of those odd materials that expands when it freezes; liquid gallium's density at its melting point of 29.8°C is about 6.1 grams per cc.)

My faithful triple-beam laboratory balance gives me quite accurate weight numbers, but I wanted a more accurate volume than fudged dimension-multiplication could offer.

When a metal has a low melting point you can, of course, just melt it and pour it into a graduated cylinder to measure its volume. But gallium, if there was any of it in this alloy, tends to "wet" a wide variety of other substances. So, presuming there was gallium or something that behaves like it in this alloy, getting all of it out of a narrow graduated cylinder again could be difficult.

Another way to measure volume is by filling a graduated container with water or oil or whatever else is compatible with the object whose volume you want to measure, and then dropping the object into it and seeing how far the water level rises. This often doesn't work any better than just measuring the edges, though. It's a good quick strategy for extremely irregular objects - figuring out this technique is what is suppose to have sent Archimedes running naked down the street shouting "Eureka!" - but I've tried it several times with different items, and every time I got miserably inaccurate results.

There's a much better way of measuring object volume by immersion, though. You just need to add a precision scale to your apparatus. Pretty-well-calibrated 0.1-gram-resolution digital scales are now commodity items, and my abovementioned lab balance will do the job nicely.

What you do is, you put some water - or, again, a different liquid if water is incompatible with the object you're measuring - in a vessel deep and wide enough to completely submerge the item whose volume you're measuring, without the object having to touch the bottom.

You then weigh the vessel and the water, or just press the zero-out "tare" button on your digital scale.

Now, you immerse the item you want to measure in the water. If it's less dense than water you have to push it down into the water until it's fully submerged, but it's probably more dense than water, in which case you can just suspend it rather than push it in.

The important part is that the object must be immersed, but not resting on the bottom of the container. This is because what you're measuring is the increase in weight of the container, not the rise in level of the liquid in it.

Whatever you suspend your object with should have as close to zero volume as you can manage. I used some kapton tape, partly because it is narrow and extremely thin yet has good adhesive, but mainly because it is unquestionably the scienciest of all of the more than two dozen kinds of tape I have to hand.

("Florists' crepe-paper tape?" Got that. "Colourful metallic tape less than a millimetre wide meant for decorating fingernails?" Yup. "Copper and aluminium foil tape?" Of course. "Self-amalgamating?" Which kind would you like, the old rubbery type or the new silicone stuff? "Gaff?" Multiple colours. "Foam draught-excluding door-seal tape?" Please. "Bendable-fridge-magnet tape?" Yes sir. PTFE thread-sealing tape? Naturally. "Unstretchable fibre-reinforced tape?" Ashamed to say I have only glass-reinforced, must get the aramid kind too. "Velcro tape and liquid tape?" Possibly the first and definitely the second doesn't really qualify as tape, but I've got 'em both anyway. And you can buy off-brand probably-kapton polyimide tape all over the place these days; it's generally just called "high temperature tape".)

Again, if you're measuring the volume of a ping-pong ball or something by the immersion method then you'll have to push it down into the water, but that'll still work. You could push it in with three needles mounted on some gantry over the scale, for instance.

Anyway, you suspend or shove the thing you're measuring into the water, suspending or shoving as little other stuff in there as possible, and the vessel will then become heavier by the mass of the liquid the object has displaced. Water weighs one gram per cubic centimetre at one gravity, so presuming you're using water and don't need numerous decimal points of accuracy, each gram of weight gained equals one cubic centimetre of object volume.

If you're now having some kind of "common sense" brain-spasm, wondering why a ping-pong ball shoved into a glass of water should make that glass as much heavier as would an identically-sized sphere of tungsten suspended in it, you may find this PDF soothing.

The initial mass of my glass plus water was 436 grams even; dangling the "bullion" ingot in it raised that to 441.5 grams, for a volume of 5.5 cubic centimetres.

This made me pleased about my original guesstimate of 5.6 cubic centimetres, though slightly less pleased about the time I'd spent bent over a laboratory scale to get a scarcely-different number. It's a bit like that story about how the Great Trigonometric Survey painstakingly measured the height of Mount Everest and came up with exactly 29,000 feet. That's exactly how tall everybody had always said the mountain was anyway, so, the story goes, they added another two feet to prevent people thinking they'd actually just gone to ground in a club in Calcutta and spent their time inventing snooker and the gin and tonic.

Anyway, 5.5 cubic centimetres and 52.6 grams gave me a density of 9.56 grams per cubic centimetre.

I now had a reply from the seller regarding what he reckoned I'd actually bought. He said:

Hi, the metal is frenchs metal type3 or gallium, both the same.


He was receptive to my then pointing out that "French's metal" and gallium are very much not the same, the latter being non-toxic and the former containing both lead and cadmium. It was at this point that he told me he wasn't selling this stuff any more on account of its headacheyness, which is I suppose one way of describing what happens when you sell poisonous heavy metals, both lead and rather more scary cadmium, as "non toxic and non hazardous to handle".

"French's metal" is an unusual term for an unpopular substance. It's easy to find people selling Wood's metal, which is bismuth, lead, tin and cadmium, and melts around 70°C. Rose's metal is also pretty commonplace; it's just bismuth, lead and tin, so not as poisonous as Wood's metal, and melts just below the boiling point of water.

French's metal winds the melting point down to only about 41.5°C by adding indium to the Wood's-metal mix. There are some further variants that melt even lower thanks to the presence of thallium as well; if this stuff really melted in your hand, I strongly suspect it'd have to be one of the thallium alloys.

Which would be bad. Especially if you were melting it in your hand.

There are very good reasons to have as little thallium in your life as possible. Cadmium is something in the order of ten times as toxic as lead, but you can at least touch the stuff with your bare hands without appreciable danger, provided you wash your hands thoroughly afterwards.

Metallic thallium can pass through the skin, though, and is much more toxic than cadmium. Exact comparisons are difficult, because human thallium exposure is usually via one of its several useful-yet-toxic compounds, rather than the pure metal. But thallium is probably tens, if not hundreds, of times as toxic as cadmium. See this PDF from the US EPA, for instance, and compare with MSDSes (previously) for cadmium, like this one or this PDF one.

You really, really don't want to get any thallium on you.

(One of the symptoms of thallium poisoning is that your hair falls out. Needless to say, this means thallium sulfate used to be used as a depilatory, not that long ago. See also the use of lead and mercury compounds for skin whitening. Thallium is also still used in some countries to poison rats, ants and troublesome spouses.)

Fortunately, most people don't need a fusible alloy that melts at as low a temperature as bismuth-lead-tin-cadmium-indium, and fewer people still need the alloys with thallium as well. Presumably, because of this relative unpopularity, "French's metal" and its relatives are often not called that, and just stuck on page 137 of the specialist-alloys catalogue with no name beside their ingredients and melting point.

On with the investigation, then. What actually is the melting point of this stuff?

If it were pure gallium then it would indeed melt in your hand, provided the ambient temperature was high enough; gallium melts at 30°C (86°F). It's too dense to be pure gallium, though, so if it melts at blood temperature then it's probably terrifyingly toxic.

"French's metal" formulations - without thallium - are frequently quoted as melting at 117°F, which is 47.2°C, way higher than any survivable body temperature. Similar alloys with added thallium are quoted as low as 105°F, which is 40.6°C and still not "body temperature" unless you're quite gravely ill. Measuring the melting point can therefore help me decide whether it's moderately-nasty French's metal or some handle-with-gloves thallium alloy.

I've got a high-accuracy digital probe thermometer, from back in the day when I reviewed incredible quantities of CPU coolers. (It's tempting to simplify the setup by just pointing one of today's inexpensive non-contact infra-red thermometers at whatever you're heating, but in this case that wouldn't work.)

So I set up the sort of advanced experimental apparatus for which I am so justly renowned...

Gimcrack apparatus for measuring melting point of fusible metal alloy

...with the metal ingot again suspended in water, but this time inside a resealable storage bag, of the type generically referred to as, but in this case not actually a, Ziploc.

The bag insulated the metal from the water, of course, and my temperature probe was in the water, not inside the bag to get all probably-cadmium-ed up. So I needed to be a bit crafty to get a useful melting-point number.

What we're interested here is how low the temperature the metal melts at is, not how high it is, if you get my meaning. So I ran the water temperature up to 50°C (122°F), at first. Then I turned the heat off and snapped the above picture of the setup, while the metal got around to melting.

Melted fusible metal in plastic bag

After taking this photo, I hung the melted metal in its bag back in the water, and allowed the water to cool.

As the water temperature fell through the low forties Celsius, the metal started solidifying again. Crystals started forming in the liquid, so at first the metal in the bag felt like a dense liquid with a little sand in it, then more and more like unusually heavy wet sand, until finally it solidified entirely.

I think this might mean this alloy is non-eutectic, with no clear melting point because different components melt at different temperatures. It could also just be the normal way a cooling metal will crystallise if you keep poking at it and examining its texture, though - the "liquidus temperature" is defined as the temperature at which solid crystals can coexist with melted material. I'm not sure.

The metal was wholly solid again when the water temperature was 40°C (104°F). Taking the bag's insulation effect into account, that told me the melting point was above 40°C and below 50°C, so the "melts in your hand" claim was clearly disproven, but I didn't yet have much idea exactly which alloy I was looking at.

I then ran the temperature slowly back up again, and the metal was re-melting, with the same sandy-liquid feel, by the time the water was back up to 47°C. But, notably, not when the water was only at 42 or 43°C, which would indicate a scary thallium alloy.

And then a pinhole opened in the corner of the bag and tiny droplets started escaping, and I terminated the experiment before I got heavy metals all over the kitchen again.

(Perhaps a genuine Ziploc® Brand bag would have been tougher. Squishing a gritty liquid with 83% the density of lead around in a the pointy corner of a polyethylene plastic intended to contain only food would probably cause any such bag to spring a leak, though.)

I could have re-bagged the metal and kept refining my temperature range, but what I'd done so far makes me confident that the melting point is somewhere in the 42-to-47-degree-C range, and probably the upper portion of that range. So I'm about 95% sure that this is indeed some kind of French's metal alloy containing lead and cadmium, but not deadly thallium.


If you want a relatively inexpensive fusible alloy to play with, go for Field's metal. It melts at about 62°C (144°F), and it contains only bismuth, indium and tin, so genuinely is non-toxic. Bismuth and indium are a bit expensive, which means Field's metal is too, but you could cast a teething ring out of it and probably not harm the baby.

Describing any of these low-melting-point fusible alloys as "bullion", though, is if anything even sillier than doing the same for copper. They're not worth enough per kilo to be an investment item, and most of them contain lead, cadmium and/or even thallium, which makes them less "valuable heirloom" and more "toxic waste".

Two low-melting-point metals, one assistive cat

Here, along with one helpful wubble, is where my own "liquid bullion" ended up. I've left it in the triangular shape the corner of the plastic bag gave it, along with the little spherical droplets that escaped into the saucepan. It's quite pretty, covered with tiny sparkling crystal surfaces; cooling it slower might have made bigger crystals, though nothing that could compete with bismuth.

To the right of the "bullion" lump is my sample of gallium, which is currently solid. Gallium is one of those substances that'll stay liquid below its freezing point if nothing serves as a nucleation point to start it crystallising. (The same thing can happen with water and various beverages in smooth plastic or glass containers).

Gallium sticks to almost everything, though, so if you slosh it around in the bottom of a container it'll make a silvery mirror out of whatever parts of the container-sides it touches. Once it finally decides to solidify - which, for my gallium at least, can take weeks - you can flick the flexible sides of the container to break the thin gallium coating off them. The result is what you see in the above picture - uneven coverage of the sides with thin plating I didn't manage to dislodge, and random dislodged flakes of gallium sitting on top of the solid layer in the bottom of the container.

(I rather like these little PET bottles, by the way. My gallium came from the Amazon seller in a tough grey translucent container that doesn't show it off nearly as well as this new one. Five of these eighty-millilitre containers, about 8cm high and 4.5cm wide, only cost me $AU3.88 delivered on eBay. They seem to be a couple of bucks more expensive now. UPDATE: But because they're standard PET bottles blown to shape from a preform, they shrink if you put them in boiling water! I think I can re-liquefy my gallium in one of these bottles, but now I've got one funny-looking one from pouring too-hot water on it.)

As I write this, the spot price of silver is less than $US20 per troy ounce; precious metals in general have taken a dive in the last few months. The spot price for gallium is at the moment maybe $US500 per kilogram, and one kilogram is 32.15 troy ounces. So gallium is something like $US15.55 per troy ounce, right up there with silver.

There is, just as with copper, no real liquid market (pun not intended) for small quantities of high-purity gallium. But the value of the stuff is sufficient that if you manage to buy it by the kilo at close to the bulk spot price, it really could qualify as an investment.

If you buy fifty grams of gallium in a little bottle from that Amazon dealer then you'll be paying a large markup on the bulk price, as is normal for metals other than the generally-accepted "precious" ones sold at retail in ounce quantities. It's also possible to quickly turn gold, silver or platinum into cash, if you suddenly need to. In a similar situation with gallium you'd have a hard time finding people who even know what it is, much less people who'll buy it from you at a fair price, in a hurry.

On the other hand, gallium's value is closely pegged to its real usefulness in the world. Gold, silver, platinum and palladium all have real-world uses, but their value is far higher than those uses justify. A large slice of the precious-metals market is people buying the stuff as an investment or just a store of value, perhaps as an alternative to a savings account in their shaky local currency. (India, in particular, has a strong tradition of storing household money in gold.)

Precious metals have never been a good long-term investment in the modern world, but they're portable and fungible, and that counts for a lot, even if you accept that you could make more money with index funds, bonds, or often even crappy-yield savings accounts.

Nobody's casting gallium ingots and keeping them in Fort Knox, though. Which is just as well, because the stuff would totally pull a Cryptonomicon if you turned the heating up too far.

A bottle of sloshy liquid non-toxic gallium is a lot more fun than a similar amount of similarly-valuable but much-easier-to-sell silver, though. I think that's a fair trade.

But don't buy weird "bullion" of any kind from eBay dealers, especially ones that say their product is non-toxic but aren't actually sure what it is. And if you are an eBay dealer selling weird "bullion", for pity's sake figure out what it is that you're selling, lest you be the next schmuck to put a "safe for kiddies!" sticker on a lump of cadmium. Or worse.

My ever-vigilant Perpetual-Motion-Claims Patrol

A reader writes:

OK so this looks really cool:

Alabama-Based CMR Demos Programmable Magnets That Changes Polarity And Strength On A Whim

As long as they don't violate the laws of physics that is. What do you think, scam or not?


Correlated Magnetics Hoverfield demonstrator

I don't see any reason to think that Correlated Magnetics are doing anything snake-oil-y. They've just got a way of making single magnets which contain multiple differently magnetised regions.

Take the above "Hoverfield" demonstration unit gizmo, for instance...

...which you can buy for a hundred bucks if you like.

Clear acrylic and magnets doing odd things do indeed instantly start some red flags waving among those of us who're accustomed to independent thinkers like Steorn who, as you say, claim to break the laws o' physics but never quite manage to actually do it. But Correlated Magnetics are not in the physical-law-breaking business. You can make a less elegant contraption that does the same thing all of their products do, at home.

Take the "Hoverfield" thing, for instance. To make your own ugly version, all you need is a couple of large relatively weak magnets, plain ferrites, for instance, and two or more small strong rare-earth magnets.

Now glue the rare-earth magnets onto the faces of the ferrite magnets so that when the ferrites are facing and attracting each other, the rare-earth magnets are facing and repelling. The large ferrite magnets have a big, weak field; the small rare-earth magnets have a little, strong one. So the ferrites attract until they're close enough that the stronger but smaller repulsive force of the rare-earth magnets equals the attractive force of the ferrites, and provided your contraption prevents the magnets from slipping sideways and ruining the demonstration, it'll oscillate to stability with the magnets close, but not touching.

Correlated Magnetics can make a magnet array that does this, but looks like an ordinary single magnet. They produce various other one-piece arrays too. "Coded" magnets that have matching pseudo-random pole patterns so they lock together very strongly but only in one orientation, for instance, and other patterns that reduce the size of the field but strengthen its holding force. (This is also how rubber fridge magnets work - rub a couple of them over each other and you can easily feel the "ridges" of polarisation that make the weak magnetic material able to actually stick to a fridge.) Correlated Magnetics have a few other such creations.

Calling these magnets "programmable" is I think a bit of marketing puffery, since they've got nothing to do with true programmable matter. If these things are really "programmable", then so are those big Edmund-Scientific-type junk-fishing magnets that you can "turn off" with a handle (which moves the magnet inside away from the external field-concentrating pole piece that the junk sticks to).

There's no perpetual motion claims here, though. leave your pitchforks stuck in the haystack, and your torches unlit.

Psycho Science is a... sort of... 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.

"Or, if you had a really galloping variable on your hands..."

I'm reading A Random Walk in Science, a compilation of science humour from rather ancient times to shortly before the book was published, in 1973.

It contains some, but not many, things I've seen before - the turboencabulator, The Contributions of Edsel Murphy to the Understanding of the Behavior of Inanimate Objects, A glossary for research reports et cetera.

The art of finding the right graph paper...
(legible version below)

My favourite bit so far, though, is The art of finding the right graph paper to get a straight line, from an almost-fifty-year-old volume of the Journal of Irreproducible Results.

This piece is not on the JIR Web site (though this other excellent graph is), and it doesn't seem to be online anywhere else, except for this site that lets you read a who-knows-how-legal copy of the whole book. (Or of course, you could download the book from a hive of scum and villainy.)

A Random Walk in Science is also still in print, too, though ridiculously expensive. So I've taken the liberty of image-ifying those two pages. Click for more legible versions.

Finding the right graph paper, page 1 Finding the right graph paper, page 2

This is probably still copyright to somebody, no warranty expressed or implied, et cetera.

I also rather like this quote from Sir Arthur Eddington:

When an investigator has developed a formula which gives a complete representation of the phenomena within a certain range, he may be prone to satisfaction. Would it not be wiser if he should say "Foiled again! I can find out no more about Nature along this line."

Competitively-priced small disabilities

Herewith, a combination of two of my favourite things: Imaginary giant Internet robots, and perceptual and cognitive dysfunction.

Today's patch for MechWarrior Online, you see, didn't just add a mildly interesting new 'Mech...

Trebuchet BattleMech

...and a large new map.

Alpine Peaks screenshot

Besides that, it also fixed a few bugs which most players, me included, should have noticed. But didn't.

The second-most-coveted "Elite" efficiency upgrade for your 'Mechs is "Fast Fire", which makes your weapons recycle to fire again 5% faster. Everybody with a 'Mech that, you know, has guns, buys Fast Fire as soon as they can.

Except, until now, it didn't work.

Worse, it worked backwards. It made your weapons recycle 5% slower.

They've fixed that, now.

But I never noticed. I've bought Fast Fire for, what, two dozen 'Mechs so far? If you'd asked me, I would have said it worked.

(The most desirable elite upgrade is "Speed Tweak", which raises your top speed by ten per cent. That always worked, though it used to only boost you 7.5% before they bugfixed that too, a few patches ago. Well, I think it always did something. Maybe it just changes the speedometer to tell you 100 kilometres per hour is now 110...)

And it was actually even worse than that, because there were several other screw-ups in the upgrade system.

People noticed some of them, like how you still have to buy the Basic upgrade "Arm Reflex" if you want to get to the Elite upgrades, even if your 'Mech is a Catapult or something that does not actually have articulated arms.

But Arm Reflex and "Twist Speed" were backwards, until now. Each actually gave the other's upgrade.

And the reason the Fast Fire problem was even worse is that when you bought Fast Fire it didn't do anything to your fire rate at all. Because, like Arm Reflex and Twist Speed, Fast Fire and "Pin Point" were reversed too!

If you bought Fast Fire you got Pin Point, and if you bought Pin Point you got Fast Fire. Which was, once again, actually Slow Fire. But when you bought it you didn't get it. Which was actually helpful, since it didn't work. Stay with me, here.

And the doubled Basic efficiencies you got from getting to Elite weren't doubled properly! And there's more!

MechWarrior Online is still in beta, so you should expect stuff like this. If there weren't bugs, even quite egregious bugs, then it wouldn't be a beta.

But you'd think errors like this would be the talk of the town. I mean, it'd be the work of a moment to do a little science to detect such things. Time some gun-shooting, or screenshot how far your 'Mech's torso can twist, or whatever. Then buy a new upgrade that's meant to change whatever you did, and test again.

But, clearly, almost nobody did that. I certainly didn't. So almost nobody noticed the bugs. This may have something to do with how long it's taken these bugs to be fixed - we're almost four months into the open beta now.

The moral of the story is, once again, that if you want to see if something is true or not, you have to do science. And science is not restricted to incomprehensible white-coated boffins who look at brightly-coloured liquids in the background of wrinkle-cream advertisements and who also dogmatically pursue the formula for the perfect biscuit dunk. Science is just careful experimentation, observation and thinking, which anybody can do, any time they like.

Some differences are blatantly obvious enough that you don't need to set up a formal experiment. You don't have to do science to determine whether it is safe to cross the road when something that looks very much like a car, but could be a hologram or hallucination, is coming. And if there were some upgrade in MechWarrior Online that was meant to make your 'Mech twice as tall or twice as fast, you'd be able to tell if it was working pretty easily with informal observation. (Though you wouldn't be able to easily determine if it were only making you 1.95 times as tall or fast...)

When something is subtle or elusive, though, as many concepts in the real world are, there is no substitute for science. And it's surprising how often it's needed.

Raining rocks

A reader writes:

If you're up for it, I'd really love an article on why the size of that meteorite varies from 10 tons to 10,000, why the rarity of it is 1 in 5 years to 1 in 100, and why the explosion is everything from 1 to 500 Hiroshimas (I hadn't realized that was a new standard measure until today).


Right after everybody started goggling at YouTube videos of lights in the sky over Chelyabinsk, and blessing once again the everlasting source of comedy and horror that is the Russian dash-cam phenomenon, a lot of reporters were probably hitting the telephones. (Or just Twitter, now that having the first story is so much more important than having the first correct story.)

Anyway, early on there was an estimate allegedly from the Russian Academy of Sciences that said the meteoroid was only about ten tons. I don't know who at the Academy first said that to a journalist, since there doesn't seem to be an official press release or anything, but that mass estimate seems tied to them.

Since this estimate came before anybody had pulled together enough reports and readings to know for sure the size, velocity and explosion altitude of the rock, it's not surprising they were way off. I presume they just estimated a relatively low airburst of a relatively small rock, enough to do this sort of damage...

...without requiring the meteoroid to be a one-per-century size.

Around the same time, the European Space Agency similarly estimated the rock to be relatively small, with the caveat that they didn't yet have "precise information on the size, mass and composition of the object".

But then NASA estimated the rock was much bigger and heavier and blew up much higher. Since then, better readings have caused NASA to estimate it was a little larger again, putting it in the one-per-century category. I think this pretty conclusively overrules the early, low estimates.

This may also make it fortunate that this meteoroid came in at a grazing angle, and exploded so high up. I'm no expert on meteorite dynamics, but if the Chelyabinsk rock had managed to get down to ten kilometres or lower before it exploded, it would have Tunguska-ed the city, not just outshone the sun and then broken lots of windows.

This may have been impossible, especially if this meteoroid was one of the common stony types. Nickel-iron meteoroids are much rarer than stony ones, but also much more likely to make it to the surface without "exploding". The explosion effect when a meteoroid disintegrates in the atmosphere comes from the much greater surface area per mass of the fragments; they decelerate faster and heat up more, creating the kaboom. Whatever bits survive this process are generally small enough that they're only travelling at terminal velocity when they hit the ground.

I think gigantic dinosaur-killer meteorites can't help but make it to the surface largely intact, and ruin everybody's whole week. At the other end of the size chart are the tiny micrometeorites that drizzle down constantly, which anybody can harvest from the roof of a building.

I agree that using the Hiroshima bomb as an explosion-size yardstick is a bit silly, since it's not as if many people now living have a personal, visceral understanding of what that means. You might as well say something like "the meteoroid weighed more than 9000 tonnes, as much as fifteen thousand adult bluefin tuna".

I propose we use the PEPCON explosion instead.

The two biggest explosions there, which happened almost simultaneously, added up to only about 2.7 kilotons of TNT. The Chelyabinsk meteoroid explosion was, according to NASA's corrected estimate, close to 500 kilotons.

UPDATE: Phil Plait, the moderately famous actual astronomer who you should obviously have listened to about this stuff before you wasted minutes of your life on the above, has a couple of articles about the Russian meteor here and here.

Psycho Science is a... sort of... 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.

More green ink by e-mail

A reader writes:

Dear Dan
I purchased some modulators from Mr Orchard and had one of the units tested using a machine called a PowerMate that is made in Adelaide.

The result was a 30% reduction in power consumption. The test was done over a 3 month period.

Mr Orchard is way ahead of his time. People just on get it!



The contents of this e-mail is highly confidential and for the intended recipient only and to the e-mail address to which it has been addressed to. It's contents may not be disclosed to or used by any other 3rd party other than this addressee, nor may it be duplicated in any way or format without prior consent by the sender. If received in error, please contact the sender by email quoting the name of the sender and the addressee and delete it from your email server and email client software. The sender does not accept any responsibility for any forms of viruses, spyware or malware. It is the responsibility of the receiver to scan all their incoming e-mails and all attachments that have been sent to them.

First, no, e-mail sent to a stranger is not confidential, and no disclaimer boilerplate at the end can make it so. (I'm not sure what the "commercial" part is supposed to mean, either.)

EMPower Modulator

That aside, I presume you're sincere about your statement about seeing the magical EMPower Modulator doing at least one of the numerous extraordinary things it's meant to, and I will also grant for the sake of argument that the test you saw was not rigged, or performed with a defective power meter. (The "Power Mate" is I think meant to be able to take reactive loads into account; cheap power meters like the ones I write about here cannot fully do this.)

In that case, all I can say to you is the same thing I say to everybody who says they know of some gadget that reduces electricity consumption, or improves fuel economy, or in some other way could save a lot of people a lot of money:

Why is the person who has been selling this thing for so many years or, in many cases including that of Harmonic Products, DECADES, not a billionaire Nobel-Prize winner?

You demonstrate your device informally. You talk journalists and a technical college or two into testing it. With that evidence, you talk serious test labs and/or universities into testing it. And then there you are with your proven invention that, because most of the world's population will want it, is not worth millions of dollars; it's worth billions. Hell, even if an evil corporate conspiracy steals your invention, rips up your patent and robs you of your rightful reward, you will still have greatly bettered the lot of humankind. Provided, of course, that the evil conspiracy doesn't tuck your gadget away in the same vast warehouse where they keep the Ark of the Covenant and the hundred-mile-per-gallon carburettor.

There are hundreds of these things. Fuel savers, power savers, perpetual-motion machines, things that allegedly enhance health or cure deadly diseases by means unknown to science, and of course persons distributing the wisdom of super-advanced aliens via channelling.

All could revolutionise the world, if true. None have ever managed it. They always just sell the gadgets, or tickets to their performances, one at a time to punters like you.

(And, notably, they do not mysteriously vanish when the abovementioned giant corporate Illuminati Freemason conspiracy catches up with them. A lot of these people have been selling the same scam pretty much all their lives, without any repercussions beyond getting serially busted by the government because they keep taking people's money and running.)

The closest these miracle devices and potions get to actual success is when they manage to be bought in quantity by someone who hasn't applied any proper tests to see if they work, or who are just hoping to turn a buck on resale or shares in the company. See the ADE 651 "bomb detector" and its various relatives, for instance, and the whole miserable Firepower saga.

If the EMPower Modulator works, it is a miraculous device, and I use that word advisedly. (The same goes for the pieces of purple aluminium jewellery that Harmonic Products told me protect the wearer from radiation, make beverages take better, make metal on your person invisible to metal detectors unless you intend to do something bad with that metal, et cetera et cetera.)

But apparently Harmonic Products are perfectly happy to frame a lottery ticket and hang it on the wall for visitors to admire.

They say it'd win a billion dollars, if they only cashed it in.

Why haven't they?

UPDATE: Peter replied to me, with the following cogent rebuttal:

Yes the world is flat and the Sun revolves around the earth.
Happy sleepwalking.

Sent from my iPhone

I'm not sure whether he's agreeing with me or not.

(There was no boilerplate confidentiality disclaimer this time. Presumably he's cool with his e-mail being published, provided he sent it from his phone.)