I have always had a great enthusiasm for musical jokes.
(Which reminds me, I must brush up my Great Gig in the Sky/Imagine/Bohemian Rhapsody medley again. I leave identification of the points where I graft them together as an exercise for the reader, until I get around to making an MP3.)
Herewith, therefore, I present you with the soundtrack of a swingin'cocktail party for all fifty million inhabitants of a Culture GSV!
Anyone with some experience of organ music will now, of course, know what the inevitable soundtrack will be, when unfortunate events later force the GSV to offload its population and convert most of its mass into engines and weapons...
After reading "Welcome to my museum", I'm now fascinated by the power supply equipment used on early Cray supercomputers. Can you explain more about the Motor-Generator Unit, and where you found the information? There doesn't seem to be much literature about it on the interwebs.
Colin
I found out about the extraordinary supporting equipment the Cray-1 needed in the "Cray-1 Computer Systems M Series Site Planning Reference Manual HR-0065", dated April 1983, which you can get in PDF format here.
You could very easily mistake that device for a modern SSD, except for minor details like how it had a maximum capacity of 256 megabytes, and was larger and heavier than some cows. I'm not sure quite how much larger and heavier, though, because that's covered by document HR-0025, which unfortunately doesn't seem to be online anywhere.
(The top-spec 256Mb version of the SSD did have a 1250-megabyte-per-second transfer rate, though, more than double the speed of the fastest PC SSDs as I write this. The Cray SSD's main purpose was apparently to serve as a fast buffer between the supercomputer's main memory and its relatively slow storage. Traditional supercomputers, as I've written before, were always more about I/O bandwidth than sheer computational power.)
The Site Planning Reference Manual is sort of a tour rider for a computer. Van Halen's famous rider had that thing about brown M&Ms in it as a test to see whether people at the venue had read the rider, and were thus aware that they needed to provide not only selected colours of confectionery, but also a strong enough stage and a big enough power supply. I presume the Site Planning Manual has in it somewhere a requirement that there be an orange bunny rabbit painted on one corner of the raised flooring.
(At this point I have to mention Iggy Pop's rider as well, not because it's at all relevant to the current discussion, but because it's very funny.)
I think the deal with the Motor-Generator Unit was that the Cray 1 needed not just enormous amounts of power (over a hundred kilowatts!), but also very stable power. So it ran from a huge electric generator connected directly to a huge electric motor, the motor running from dirty grid power and the generator, in turn, feeding the computer's own multi-voltage PSU. The Cray 1 itself weighed a mere 2.4 tonnes, but all this support stuff added several more tonnes.
(My copy of the HR-0065 manual is over on dansdata.com, hosted by m'verygoodfriends at SecureWebs, who in their continuing laudable attempts to wall off IP ranges corresponding to the cesspits of the Internet occasionally accidentally block traffic from some innocent sources, like an Australian ISP or two. If you can't get the file there, you can of course go to Bitsavers instead, or try this version, via Coral. You can use Coral to browse the whole of Dan's Data if SecureWebs isn't playing ball, though it may be a few hours out of date.)
I was watching "Industrial Revelations" on Discovery, and I noticed a lot of Industrial Revolution factories running from one power source, a steam engine or waterwheel, with power distributed via a load of parallel overhead shafts, which brief Googling tells me are called line shafts. A belt runs from each shaft to each working machine, often with a free-turning wheel next to the one that drives the machine so the belt can be moved over onto the free wheel to "turn the machine off".
What I can't figure out is, what kept the belts on the wheels? They don't have ridges on the edges to contain the belt, they're not V- or U-profile with a matching belt shape, they're just flat metal as far as I can see, yet the belts don't fall off.
Traditional flat leather drive belts were a pretty good piece of technology. They weren't even as much of a death-trap as you might think just looking at them, since they often had enough slack that getting some piece of yourself or your clothing caught between belt and pulley wouldn't necessarily whip you into the air or smash your face into the machine. Getting your hand caught in the moving parts of the steam engine or waterwheel gearing on the other end of the lineshafting system was bad, bad news, but if only a belt had grabbed you, you had at least a fighting chance of yanking yourself free. There usually wasn't even enough pressure between belt and wheel to instantly crush your hand.
But this arrangement looks even more insultingly physically impossible than lineshaft setups. That dang belt should fall off the engine right away, shouldn't it?
Occasionally, there's a flat belt that runs on a spool-like pulley with raised flanges on the edges, like the small receiving pulley in the above picture, or this one:
On all but the biggest of the Towers-of-Hanoi stepped sections of that pulley, the belt can only fall off on one side. But where's the power for the stepped pulley coming from? Another dang flat pulley, that's where!
Free-spinning idler wheels weren't the only way of stopping a machine, either; the middle belt in this piece of lineshafting...
...has been taken off the wheel to stop it driving. That's "taken off", though, very probably not "fallen off". Left to its own devices, it'd stay where it was meant to.
The secret is that the "flat" pulleys on which the belts are running are not, actually, flat. If you look closely, at for instance the stepped pulley picture above...
...you can just about see that the pulley surface profile is slightly convex, or "crowned". The profile of the pulley is sort of like that of a wooden barrel, except less pronounced.
Wherever a flat belt is on a crowned pulley, it will tend to move towards the centre. This effect is reliable enough that some of the pulleys in a flat-belt power-transfer arrangement actually can be completely flat, as long as every belt runs over one or more crowned pulleys somewhere else.
For practical purposes, you can stop here. Slight convex profile to pulley equals flat belt staying in the middle of the pulley. Provided all other pulleys are well enough aligned, at least; if the pulleys aren't lined up very well then even if all of them are crowned, the belt may still "walk" off one of them. But basically, crowned pulleys equals centred belts.
If you want to know why crowned pulleys work as they do, things get a little more confusing. Confusing enough, actually, that the question can be presented as a puzzle, or even as a "paradox".
(Crowned pulleys are much more confusing than tax brackets, but I think less confusing than wind-powered vehicles that travel faster than the wind.)
The edge of a flat belt that is closest to the middle of a crowned pulley will be stretched a little more than the other edge of the belt, because the crowned pulley has a greater diameter in the middle. This gives the belt-edge toward the middle of the pulley higher tension and thus more traction than the other edge. So wherever the more tense, higher-traction portion of the belt wants to go, the whole belt will tend to go.
Any given point on the portion of the belt in contact with a pulley will, by definition, contact a point on the pulley. But when the pulley is crowned and the belt is not in the middle of it, the slight bend in the belt means a point on the tenser side of the belt, closer to the middle of the pulley, will be unable to stay in contact with the same point on the pulley as it rotates. The slight bend in the belt created by the crown profile points the belt away from the middle of the crown profile. All parts of the belt in contact with a pulley "want" to stay in contact with that same part of the pulley - that's sort of the whole point of friction belts on pulleys. But because the tenser edge of the belt, closer to the middle of the pulley, has more grip than the other edge, the whole belt tends to climb to the middle of the pulley.
This illustration from The Elements of Mechanism, which I found on this page explaining the aforementioned "paradox", may help you visualise this. It certainly helped me. The point on the pulley (in this case two truncated cones, not a smoothly curved crown) which is under point "a" on the belt will end up at point "b" as the pulley rotates. The belt tries to stay frictionally stuck to the same part of the pulley, so it climbs to the middle.
(A "perfect" crowned pulley with a smooth curve is a bit of a nuisance to make, so some crowned pulleys have a flat centre and curved, or even conical, ends, and some are as shown in the above picture, just two truncated cones stuck together base-to-base. These designs don't work as well - a belt will wander on the flat part in the middle of the first type, and the ridge in the middle of the second type reduces grip and wears the belt - but they work well enough for many purposes.)
The crowned-pulley effect isn't very strong unless the crown shape is very pronounced, which would make the belts wear out quickly; this is why it can't compensate for more than slight misalignment of the pulleys. Pulleys with raised edges of one kind or another - including V-profile belts and pulleys and their relatives - can tolerate much more misalignment.
(An exaggerated crown shape does make the crown effect much easier to see, though. Famous Web-woodworker Matthias Wandel has a page about the crown effect too, that includes an exaggerated pulley.)
Although the era of lineshafting has long passed in the Western world, flat belts and crowned pulleys survive as conveyor belts, and in the strangest other places - the paper-handling machinery in photocopiers, for instance!
You can also set up a model steam engine to run a whole model machine shop via tiny line shafts. Most such setups, however...
Why do nuclear power stations (and other power stations, for that matter) have cooling towers in that weird half-hourglass shape?
I presume the guys who built them knew what they were doing, but what did they know that I don't?
Ian
I pledge to eventually answer your question, Ian, but first I'm going to rabbit on interminably about power stations.
The cooling tower has become emblematic of nuclear power stations, and the white "smoke" drifting from the top of them is a source of vague nervousness for a lot of people.
But, as you say, other kinds of power stations have cooling towers too. I live less than an hour's drive from Lithgow and the Mount Piper and Wallerawang Power Stations, able to produce 3.4 gigawatts of coal-fired electricity between them; Mount Piper has two cooling towers, Wallerawang has one. The "smoke" that comes out of these towers is actually just clouds of tiny water droplets.
(Once again, if you can see it, it's not "water vapour". Clouds, and the visible "steam" squirting out of a kettle or a steam locomotive, are liquid water droplets with a ceiling temperature of 100°C at sea-level air pressure. It's possible for actual invisible-vapour steam to be swirled in with condensed droplets as it mixes more or less chaotically with the outside air, but "pure" steam is invisible, and has no ceiling temperature. Put your hand in the visible portion of the steam coming out of the side of a locomotive and you may get scalded, but putting your hand in the invisible jet close to where it's exiting may flense the flesh from your bones.)
Power stations need cooling towers, or some other heat-sink like water from a convenient river, because they are heat engines. Heat engines, as I've written before, become more and more effective as the temperature difference between their "hot end" and their "cold end" increases.
A heat-engine that makes this fact obvious is the now-quite-standardised sort of "coffee cup" Stirling engine...
...which stands on a wide circular displacer-piston cylinder and can run on the heat from a cup of coffee or tea, or backwards on a cup of ice-water. I've got one that runs like this, but really low-friction versions of the design can run on the heat from a human hand, if the ambient temperature is cool.
(You can pay quite a lot of money for a jewel-like Stirling engine {or, more interestingly, a kit to build one}, but this eBay dealer, in addition to being called "Stirlingeezer" which ought to be a reason to buy from him all by itself, sells quite beautiful engines and kits that are guaranteed to run from hand-heat. If enough people buy stuff via the above affiliate link to Stirlingeezer, I shall soon be able to afford one of his engines!)
(Oh, and if you're short of money, you can get a Stirling kit for $US30 delivered, or conceivably less if you get lucky with your bids, from this guy in China.)
Conventional power stations, whether fired by coal, combustible gas of one kind or another, or a nuclear reactor, make their electricity by turning a turbine connected to a generator. Gas-fired stations can do this directly with a gas turbine, which is essentially a jet engine tuned for shaft-turning power, rather than thrust. Coal and nuclear stations make electricity less directly, by using the heat of combustion or nuclear fission to boil water and run a steam turbine.
(I think there are also gas power stations that use steam turbines. There are definitely gas power stations that burn the gas in one turbine, and then run another, different turbine from the hot exhaust of the first one.)
Anyway, that's the hot end. A well-designed heat engine will try to get its cold end as distant in temperature from the hot end as is practically possible. The ratio between the two temperatures, expressed in Kelvin (or any other temperature scale, as long as it starts at absolute zero), determines the maximum possible efficiency of a heat engine.
Sometimes "the cold end" is synonymous with "the exhaust temperature"; that's how it works for internal-combustion piston vehicle engines, and steam engines too. A classic example of the latter is the triple-expansion compound steam engine. This has one small piston for the fresh, hot, high-pressure steam right out of the boiler. The medium-heat, medium-pressure exhaust from this first piston powers a medium-sized piston, and the low-heat, low-pressure exhaust from that piston in turn runs one or more even bigger pistons. (This can theoretically be extended to even more stages, but in practice quadruple-expansion was about as far as anyone could get before the gain in efficiency wasn't worth the extra complexity and friction.)
Steam-turbine power stations, on the other hand, may emit exhaust gases from the burning of fossil fuels, but the system that makes the actual electricity is a closed, Rankine-cycle steam/water circuit. The burning fuel or fissioning atoms heat cool water to steam, the steam turns a turbine or three, and the turbine exhaust then goes to some sort of cooling device, generally a heat exchanger, that dumps the final unusable portion of the water's heat somewhere.
This "somewhere" can be a separate water supply, either a river, large lake or sea, or it can be evaporating water in a cooling tower. Once the heat exchanger has cooled the closed system's water in whichever way, that water is pumped into the boiler again, and the cycle continues.
You might wonder why you need to dump heat from the turbine exhaust, when you're only going to heat the water up again in the boiler. There are two practical reasons for this.
The first reason is that the exhaust from a power turbine is almost all still water vapour, because, in brief, turbines made to run on a flow of hot gas do not like it if the gas condenses to liquid inside them.
The second reason is that the pump that returns the water to the boiler has the opposite preference; it only works with liquid water. It would be possible to use a gas pump instead and make a system in which the working fluid is always vapour, but the energy needed to run a gas pump against pressure from the boiler is high, while the energy needed to run a water pump is trivial (by power-station standards), on account of the incompressibility of the water.
The upshot of all this is that standard 20th-century power stations are pretty miserably inefficient. Today, there's much more effort being made to reduce the heat wasted, by for instance transferring some of the heat of the turbine exhaust to the water feed between the pump and the boiler, or by using some of the waste heat to keep nearby buildings warm ("cogeneration"). These sorts of measures can only go so far, though, so cooling towers of one shape or another will continue to be built.
Which, finally, brings us back to the classic cooling-tower shape.
Cooling towers actually come in all shapes and sizes; large air conditioners, for instance, often have evaporative coolers for their chillers, but those coolers don't look anything like a power-station cooling tower.
Power-station coolers have to have very large capacity, so they inescapably have to be very large. Power-station coolers also have to provide a decent convective "stack effect", also known as "draught" (or "draft", in the less-demented American spelling). But, importantly, power-station coolers don't really need to be able to hold up much more than their own weight, plus any remotely plausible wind loads or shifts of their foundations.
The classic curvy cooling-tower shape fits all of these requirements. In engineering terms, because cooling towers don't need to hold up an interior full of offices, they can be built as a "thin-shell structure". You could build a cooling tower out of giant Great-Pyramid stone blocks if you wanted to, but a surprisingly thin reinforced-concrete shell, built in layers from bottom to top (not unlike the way 3D printers work), is the usual solution. And the builders almost never balls it up.
Objects of this shape are called "hyperboloid structures"; they're strong for their weight and so have been used for all sorts of masts and towers and, sometimes, ordinary buildings too, and they're particularly suited for use as cooling towers. The large area at the bottom of the hyperboloid gives lots of room for evaporation, the "waist" accelerates the gas mixture (I think because of the venturi effect), and then the widening opening at the top encourages turbulent mixing with the ambient air. (Air gets into the tower in the first place via an open latticework section around the base.)
The final question that occurs to me in this area is why cooling towers are hyperboloids, but factory chimneys are cylindrical (or close to it - they often taper a bit toward the top).
This is because the cooling tower wants to move a vast amount of low-pressure air. The evaporating warm water at the bottom of the tower produces a steam/air/water mixture that isn't much warmer, and thus less dense, than the ambient air, so it has little buoyancy compared with the ambient air, won't move terribly fast, and so has to pass through a really wide pipe. Factory chimneys, on the other hand, are moving a much smaller volume of much warmer gas, usually combustion-product "flue gas". This is usually quite a lot hotter than ambient, so it rather wants to go up a chimney and doesn't need a wide one; you just need a nice long chimney, both to get a strong stack effect and to discharge the gas as high up as possible, to spread the pollution by dilution, as it were.
(Incidentally, The Secret Life of Machines addresses the stack effect in episode five, on central heating. And while I'm on the subject, the extraordinary documentary Fred Dibnah, Steeplejack features the titular working-class hero climbing hundreds of feet up a brick chimney and then perching on scaffolding that looks as if it were assembled by blind drunkards and knocking the chimney down by bashing bricks, one by one, into the flue. It has to be seen to be believed.)
This extraordinary object looks as if it came from outer space.
It's around 11 centimetres long (4.3 inches). It weighs a bit more than 170 grams (six ounces). Its overall colour is a sort of greenish black. But it's entirely composed of darkly reflective crystalline facets, ranging in size from microscopic to about 8mm (5/16ths of an inch) in length.
On close inspection, the mass of crystals comes in a dark rainbow of different colours; yellows, blues, purples and reds.
Just like solid chromium, this stuff doesn't look real. Like the chromium, it looks more like some sort of movie prop. But my chromium lumps look like rocks spray-painted silver for an Original Series Star Trek episode in which those silver rocks were the most valuable object to appear. This stuff isn't nearly as shiny, but is much flashier, if you get my meaning. It's detailed. It's high-definition. It looks like a prop from a sci-fi movie we won't have the technology to make for another ten years.
You know what it looks like? It looks like black kryptonite, that's what it looks like.
(If you ask me, it looks better than the actual black kryptonite prop from Smallville. I presume you all share my incredulity that it took them until 2004, the 66th year of Superman's existence, to add the seemingly obvious black to the host of other kryptonite colours. Oh, and this Flickr user had the same thought, about what looks to me like the same material.)
Or possibly this stuff is what was left over after Gus Gorman boiled some home-made kryptonite in ammonia and ether and then smoked it.
This mass of black crystals is actually a chunk of crystalline silicon carbide (SiC), which I purchased quite cheaply on eBay (see below. There's video, too!).
This means it must be man-made, because natural, "native", silicon carbide does exist, but it's fantastically rare. It takes a lot of energy to persuade silicon and carbon to form a molecule.
Native silicon carbide is known as "moissanite", and so are simulated diamonds made from high-purity SiC. Far, far more SiC is made for use as an industrial abrasive or super-hard coating for tools, though, and some such process probably made this lump of the stuff.
Silicon carbide is so widely used as an abrasive because its Mohs hardness is as high as 9.5, between corundum (sapphire, ruby, and a component of emery) at 9, and diamond at 10.
Those numbers are misleading, because the Mohs scale is ordinal; it tells you what's harder than what, but not by how much. There are different ways of measuring the hardness of a material - compare and contrast the Knoop, Vickers and Rockwell tests, for instance. Whatever method you use, if you do a relative-hardness test, pretty much everything looks sick compared with diamond.
Assign a relative-hardness score of 10 to diamond and, depending on what test you use, corundum may score as high as 2.63 or as low as 2.2, and silicon carbide may score as high as 4.63 or as low as 2.5. For further comparison, quartz, generally regarded as a pretty hard material, scores down around one, if diamond is 10.
(In view of this, the fact that humans are now finally more-or-less managing to make exotic materials that are actually harder than diamond is quite amazing. The most widely used new super-hard material is diamond-like carbon, which as the name suggests isn't actually "better" than diamond, and two of the other candidates are actually just novel forms of diamond. Only minuscule amounts of the best non-diamond candidate have been made to date - with some debate over whether any of it has actually been made at all. But one way or another, we're doing it, and the achievement is a lot more impressive than a mere Mohs hardness of "11" would suggest.)
I don't know exactly how my lump of SiC was made, but I suspect it was an unwanted byproduct of some industrial process, perhaps one or another kind of vapour deposition. The carbide is meant to coat drills or saws or something, but it deposits elsewhere on the equipment too. When some lucky duck gets to clean out the machinery, stuff like this crystal mass ends up in their bucket.
Most industrial waste is not particularly decorative, but every now and then, somethingextraordinary comes along.
I also don't know how pure this carbide is. High-purity silicon carbide can be black, just like this material, but there may be various impurities in there too.
The surface is definitely not pure SiC; the rainbow reflections are created by a very thin layer of silicon dioxide on the surface. This interacts with light in the same way as various other super-thin coatings, like the surface of anodised titanium, the "rainbow of temper" on steel, or a soap bubble, for that matter.
Silicon carbide is very hard, but rather brittle. If you buy a chunk mail order like I did, you're going to get a few broken-off crumbs in the box along with the main piece, unless the seller packed the carbide in thick cotton wool. And if they did pack it in cotton wool, you're going to spend forever picking cotton shreds off the pointy crystals. Just hitting the thing with a blowtorch might be a faster solution. Or it might heat-shatter.
You don't really have to treat SiC like the egg of a tiny bird, though. When I deliberately broke off a little crystal stuck to the main mass by a couple of millimetres of hair-thin filament, I was surprised to see the filament bend a good five degrees before it snapped. And tiny crumbs coming off even a small SiC lump won't make any obvious difference to its appearance.
One thing you probably don't need to worry about your silicon carbide doing is melting. The melting point of pure silicon carbide is 2730°C, 3003K, or 4946°F in the old money. So you may be able to melt it with an oxy-acetylene torch; the theoretical perfect-combustion temperature for that is around 3500°C. Oxy-hydrogen might manage it, too. MAPP-gas and oxygen probably won't cut it, though, and no cheap butane torch will come within a hundred miles.
Silicon carbide was the material used for the very first light-emitting diode, way back in 1907, though this discovery was largely ignored at the time. That could be why nobody managed to make an LED bright enough to be useful for anything until the Sixties. Henry Round's original discovery was still scientifically important, though, and I swear I managed to get a tiny spot of my chunk of SiC to light up under a pin connected to minus 12 volts. But once I set my camera up, it refused to do it again, no matter what I poked with the pin or where I attached the positive cable's alligator clip.
I think having an alligator clip as the positive terminal, rather than for instance sitting your SiC chunk on aluminium foil that's connected to positive, is important - you need pressure on the SiC to get a decent contact, and the positive connector needs to be close to the point you're poking with the negative pin, or the semiconducting SiC won't let any current flow. With the clip close to the pin (less than a centimetre), something above 20 volts always persuades my SiC to allow current to flow, but that doesn't give the LED effect, just little blue sparks. You're looking for something greenish-yellow, as in this Wikipedia picture:
(The picture is from this page, which contains further instructions on how to try this experiment yourself. And then there's this dude, whose carbide lump seems happy to light up all over, damn his eyes.)
Trying, and failing, to make my own carbide-LED picture was quite frustrating. I can see why people in the early days of radio were so happy when they could buy machine-made vacuum-tubediodes so they didn't have to fool around with super-fine wires and lumps of galena any more, poking around all over the crystal like a tiny pirate seeking one buried treasure chest on the whole island of Barbados.
Aaaaanyway, you may be pleased to know that I am now finally going to tell you where I got this stuff, and what it costs.
Getting some
I bought a little chunk of crystalline silicon carbide on eBay a few years ago, from this seller, but they don't have any SiC for sale at the moment. This new bigger chunk was another eBay purchase, for $US28.17 including delivery to me here in Australia, from this seller (who's here on eBay Australia, here on eBay Canada, and here on eBay UK).
As I write this, they've got one more lump of the stuff, closer to spherical than mine and weighing 210 grams.
The inimitable Theodore Gray has a chunk of this stuff too; he bought it on eBay as well, but from a seller who called it "native bismuth". Dark SiC crystals resemble bismuth hopper crystals (see here) in colour, but that's as far as the resemblance goes.
(Theo also has this different-looking SiC sample, which was also sold as bismuth. And then there are these high-purity crystals, transparent green with no oxide layer. Oh, and on the subject, if you get a solid block of carbide but yourplutonium hasn't arrived yet, you can pass the time with some microwave metal melting!)
Nobody on eBay seems to be selling silicon-carbide "bismuth" at the moment; there's plenty of "native bismuth" crystals that're obviously actually purified bismuth crystallised by the standard stovetopmethod, but at least those actually are bismuth, so by eBay fake-minerals standards no great crime is being committed.
And now: Twinkling!
Behold, the silicon carbide lump, and the chromium, and a couple of large oval-cut cubic zirconias ("CZs") into the bargain. They all look impressive in sunlight.
(These videos don't have sound. Feel free to add your own vocal "ting" sound effects to synchronise with the reflections and refractions.)
The smaller CZ is, at about 36 by 29 by 22 millimetres (1.4 by 1.1 by 0.9 inches), comfortably in the Crown Jewels size range. If it were a diamond, it'd be around 155 carats (as a CZ, it's 255 carats - CZ is about 1.6 to 1.7 times as dense as diamond). This is a bit less than the original cut of the Koh-i-Noor, but about 1.5 times the Koh-i-Noor's current size.
The larger CZ is about 52 by 38 by 28 millimetres (2 by 1.5 by 1.1 inches), and weighs 132.5 grams; a diamond the same size would be about 400 carats, far larger than any of the world's famous colourlessdiamonds, and a little less than the total weight of all of the multicoloured diamonds in the two "Aurora" displays.
I bought both CZs in 2009 from this eBay seller; the smaller one cost me $US19.95 delivered, and the bigger one was $US37.95.
That seller doesn't seem to have a lot of huge CZs on offer today, but if you use the always-entertaining "highest price first" sorting option but set a price ceiling at, say, $100, then in among the eBay listings for bags containing many small CZs, there are plenty of monster white and coloured stones.
(Here's that search on eBay Australia; it's here on eBay UK, and here on eBay Canada. I strongly recommend you buy at least a pocketful of small CZs; they make novel presents, and you can also wrap them in black felt, go to a cafe with a friend, wait for people to look, and then make everyone think some serious state secrets are being sold.)
From: "freemason illuminati" <noreply@freemason.org>
To: yourorder@fi.org
Reply-To: order@illuminati.umail.net
Subject: fi
Date: Tue, 20 Mar 2012 07:10:41 +1200
You are receiving this mail in regards of the freemason confraternity of the
whole wide world (FCWWW).
You are moving well in what you are doing but in order to make it easier for
you, we have concluded for you to be a part of us as a member to sign your
life to us and have any thing you need.
Be it any thing in the whole wide world.
You can't refuse us now for it's too late.
Get back to us now for your Illuminati membership Order and also for you to
know more about the ancient ILLUMINATI FORUM and also the Orientation and
goals that we pursue.
Get back to acquire your goal now.
I would appear to not be the only person who is moving well, et cetera. The Freemason Confraternity of the Whole Wide World also seem to be offering a better deal than the LaRouche people.
Fi.org is registered to someone in Denmark, and rather appropriately www.fi.org currently redirects to shady.dk. But that's just a parked domain now; it looked something like this in 2007. The Internet Archive have numerous copies of fi.org going back as far as 1998, but they all seem to be parked-domain redirectors too.
Something has been bugging me for a while, but I didn't want to ask anyone in case it sounded racist, which it isn't, because some of my best friends are members of the inferior races which Asians like me will soon enslave.
Internet anonymity lets me ask YOU, though:
Why do old black people so often not look as old as identically old white people?
I'm asking now because I've seen a few excellent examples in just the last few days.
I was watching Joe Morton in Eureka, and he looks EXACTLY THE SAME as he did in Terminator 2, 20 years earlier.
And look at this guy! He just died at age 75, but in the picture of him performing a year ago he could be 50, or 40 even.
And then I watched a recent Daily Show where George Clinton did a walk-on, he's 70 but looked 50, tops.
(OK, there was some latex work there too. But you can't see that clearly even in HD, and he still looks old.)
I know black people don't actually LIVE any longer, quite the opposite here in the States, but looking young your whole life has to be some consolation. How/why does it happen?!
Z
I have heard this phenomenon described as "black don't crack", but I, like you, don't know whether it's safe for non-black people to call it that in company.
In the case of people in TV and movies this phenomenon is, of course, at least partially the result of makeup, lighting and plastic surgery. But you're right when you say that it happens in "real life" too.
The reason is actually quite simple.
When you get older, your skin loses elasticity and you get more wrinkly. The principal factor in the visibility of wrinkles is light, or more precisely shadow. Wrinkle-hills cast shadows in wrinkle-valleys, and those shadows play a big part in making a face look old.
If you've got pale skin, wrinkle-shadows show up very clearly. But the darker your skin is, the closer to the shadow shade it all is naturally, and the less obvious are the wrinkle-shadows, and the less old you look. That's really all there is to it.
Rub your face with lampblack and, no matter what colour your skin was before, it'll now be so dark that wrinkle-shadows will be almost invisible. Do the same thing with titanium dioxide powder and every tiny line will stand out clearly, unless you're only illuminated by a light right next to the viewer.
(This is why the built-in flash of a compact camera tends to make everybody's face look flat and weird - but not wrinkly! A photographer may use a "beauty dish" to add a controlled amount of this effect to a portrait.)
This same phenomenon can be seen in some peculiar places. Take the moon, for instance.
A full moon is much more than twice as bright as a half moon, because of what's called the "opposition effect". The effect is partly caused by the retroreflective qualities of lunar regolith - it tends to reflect light back the way it came. There may be some quantum weirdness involved too. But the opposition effect occurs mainly because the lunar surface is very uneven, thanks to meteorite impacts and no erosive forces. So there are lots and lots of shadows when the moon is illuminated from the side from our point of view, making it half-full, but there are almost no shadows at all when it's full, and illuminated by the sun looking over the earth's shoulder, as it were.
(The albedo of the moon is surprisingly low - it's about as dark as an asphalt road. It seems so brilliant in the night sky because it's illuminated by direct sunlight, not because it's actually the pale grey it seems to be when compared with the surrounding dark sky.)
The "black don't crack" phenomenon is one small part of numerous more-or-less-racist theories that explain one or another kind of physical advantage that dark people are supposed to have over pale people.
One of the more popular of these theories is that black slaves were literally bred to be stronger and healthier, since there wasn't much of a market for longsighted asthmatic cotton-pickers. Whether the claim is that this breeding was forced by slave-owners, or was just a result of brutal natural selection that caused weak slaves to often die before reproducing, though, it's pretty clear from genetics and genealogy that it actually didn't happen.
There is evidence for something like this in some situations. It's hardly surprising, for instance, that a number of successful very-long-distance runners have come from cultures where, for centuries or even millennia, being good at cursorial or persistence hunting has been a way to get more wives and offspring.
Even in these situations, though, there are many confounding factors. Running is something almost anybody can do, almost anywhere. It requires no expensive equipment or special facilities. So poor countries, regardless of culture, produce more runners than they do, say, golf or polo players. (And every now and then along comes a little white guy who's accustomed to spending days on end rounding up sheep, on foot.) For the same reason, you don't see many bobsled teams from countries where it doesn't snow.
(While I'm digressing, here's a note even less relevant to the original question: Because I'm in Australia, thedailyshow.com doesn't want to show me that George Clinton video. I just get a "Sorry, this video is unavailable from your location" error. If you have the same problem, you can solve it with the Modify Headers Firefox extension, which lets your browser say it's asking for the page on behalf of a US IP address. Find instructions on how to do this here.)
It is possible that you do not, as a matter of course, have at least fiftycockatoos turn up in your back yard for a feed every afternoon.
If you do, I advise you to, as I do, purchase your bird seed in 25-kilo sacks, and not attempt to feed the cockatoos with a supermarket seed bell.
Those don't last.
(Available in HD!)
The loud scrapey-thud noises happen every time a 900-gram bird uses the microphone on top of the camera as a perch.
Extension of this behaviour brought the video-shooting to a halt when only about half of the seed bell was gone. But, as I said, you get the idea.
(I know it's not good to give them a small source of food so they fight over it. The regular seed I spread on the table, and on the deck itself, which greatly reduces the Skesis act.)
