The Blackout Party (it's not what you think)

Last night I went to a party to commemorate a disaster.  On August 14, 2003, the northeastern United States suffered cascading power failures that left tens of millions of people in the dark for days.  To the best of my knowledge, no one at our party blacked out.

The restaurant/bar Melt has been holding a Blackout Party every year on that date, turning off the lights and TVs and serving dark beers in the dark.  Well, it wasn't very dark at 5PM with the windows open, but it was cozy anyway, and everybody looks better by candlelight.  Good thing, because we waited two hours for a table.  The company of good friends and the availability of Stone's Sublimely Self-Righteous Ale (yes, they really named it that), made the wait a pleasant one.

I'm surprised to learn now that the power failures initiated in the Cleveland area; I wasn't living here at the time.  Apparently trees had grown too close to several important power lines, and when they were asked to carry extra capacity, they came into contact with the trees and failed. 

(Here's something sciencey:  the extra current the wires were carrying caused them to heat up like resistors, which caused them to expand, in turn causing them to droop, which brought them into contact with the local foliage, which shorted them out to ground.  You gotta watch out for thermal expansion.)  

Having just spent a hard day hacking back bushes in my yard, I can testify to how much effort it takes to keep Ohio's greenery under control.  Still, it sounds like First Energy kind of fell down on the job that day.

Where was I?  In August of 2003 I was living in the Chicago area, hard at work renovating our first house.  We had frequent power outages, some of them long enough that we became concerned for our elderly neighbors, but we weren't affected by the Big One.  Perhaps Chicago had earned immunity eight years earlier with a deadly heat wave.  To the best of my knowledge, nobody commemorates that dark week.

Don't rush for the microscope, son.

In grad school, when I'd get some new sample to look at, I was always excited to analyze it with the coolest new toys I'd been learning to use.  But my advisor would tell me, "don't rush for the electron microscope."  You might miss the forest if you're focused on the, you know, amoebae.

His very concrete and sensible suggestion was to start by looking at a new thing with your bare eyes.  Learn what you can - what color is it?  Is it heavy?  Then put it in the miroscope--the optical microscope, at minimum magnification.  Turn up the mag step by step.  Then maybe the scanning electron microscope.  Then, and only then, the transmission electron microscope.  The atoms can wait, they'll still be there.

When you're handed a task at work, do you just carry out your job description, or do you check for inconsistencies to make sure your time wouldn't be wasted?

When you contemplate a new cell phone, it might behoove you to ask first not how fast its processor runs, but rather, "would it get signal in my house?"

Who are these grainy people and what do they mean to me?

I was quite touched by this image.  One of my professional specialties is the interaction of X-rays with matter, so the 20th century's advances in physics and math became matters of great practical importance to me.  I can hardly imagine putting more names from my education into one photograph.  Click for big.

In 1927, the leading lights of physics gathered in Brussels for a conference, and this photo was taken.  Wilhelm Roentgen, the discoverer of X-rays and recipient of the first Nobel Prize in physics, would have rounded it out nicely had he not passed away four years prior.  1927 was the year the Copenhagen Interpretation of quantum mechanics was being worked out.  They were chaotic times:  in 1924 de Broglie (right of center) had put forth his theory that matter could be described as either waves or particles; his doctoral committee felt that the only person on Earth capable of judging whether it had merit was Albert Einstein.  Here they are together.

• Schroedinger - the wavefunction.
• Pauli - the exclusion principle.
• Heisenberg - quantum uncertainty.
• Brillouin - propagation of electron waves in a crystal lattice.
• Debye - the effect of temperature on X-ray diffraction patterns.
• Bragg - the original crystallographer - discoverer of the laws of X-ray diffraction.
• Dirac - for me, the "Dirac delta", an infinitely short and infinitely intense pulse.
• Compton - inelastic scattering of X-rays.
• de Broglie - wave-particle duality.
• Born - the probability density function.
• Bohr - the structure of atoms.
• Langmuir - plasma probes.
• Planck - the blackbody spectrum.
• Curie - radiation, and probably the first death thereby, in 1934.
• Einstein - yeah, him.

The image I've posted is a composite of a high-resolution photo, which I found at wikimedia commons, and its seating chart, which I found elsewhere at low resolution.

Little technical problems add up to big money

The Pentagon estimates that 3% of America's GDP is spent fighting corrosion.  That's right:  rust costs us $1000 per person per year.  They have an entire budgetary office dedicated to corrosion R&D.  You might be surprised, but I'm not - corrosion is a major subfield of materials science.

They could have said the same thing about friction.  In my last gig, I worked on lubrication, which saps 10% of all the energy (read:  fuel, carbon, dollars) used in the transportation sector.  That's not just cars but also heavy trucks, rail, aircraft, and watercraft, with a total energy consumption measured in tens of "quads".  That's a euphemistic abbreviation for quadrillions of BTUs of heat per year.  One quad is equivalent to about 170 million barrels of oil.  I'm not kidding.

Farther from my personal expertise, the nation's electricity distribution system is not perfectly efficient.  In getting current from the power plant out to houses and factories, about 7% of the power is lost as heat.  A lot?  Yeah.  Easy to fix?  Not very.

These are the seemingly simple scientific issues that it turns out have vast influence on our nation and our planet.  This is why we professionalized science:  because there are problems to solve that are both deep and immense.

Cool thing of the day: Fordite

The word Fordite induces cognitive dissonance, doesn't it?  It sounds like a combination of cars and rocks.  Well, the alternate term "motor agate" does too, and it piqued my curiosity.

http://www.etsy.com/listing/30958227/motor-agate-fordite-and-sterling-silver

According to the Fordite history page, this manmade mineralesque material was formed in the paint booths of Detroit.  Early car-painting techniques were pretty wasteful, and every floor, wall, and fixture accumulated baked-on overspray until it had to be chiseled off. 

These paints were epoxies, or basically oil paint:  pigments in simple mixtures of thinners and oils that polymerize (turn to plastic) via oxidation.  In this case they were very thoroughly cured by repeated baking in the paint booth.  Many of the pigments were toxic--you only need to think about lead-based paints--so I don't know how I'd feel about my wife wearing a necklace of the stuff against her skin.  A ring, like the example above, is perfectly safe.

* * *

As a follow-up to the metallurgical display case post, I've just discovered that they're making rings out of ceramic.  They're not exciting structural ceramics like silicon nitride, but they're the real thing and characteristic of the breed:  lightweight, hard as hell, and brittle.  The ceramic used seems to be zirconium oxide, familiar to jewelers in single crystal form as fake diamonds (yttria-stabilized cubic zirconia) and to dentists as fake teeth.  They're available in white, black, and a couple pastel colors.  And they're cheap!

The metallurgical display case

Dave Cunix looked at my hand at the Blogger 11th Birthday Fiesta and commented that my rings seemed to be multiplying. They weren't - I'd just moved one from my right hand to my left - but as of today I have a new one.

On the left is my platinum wedding band, with a few dings because platinum, a noble metal like silver and gold, is soft. Platinum shares its face-centered cubic arrangement of atoms with other soft metals such as aluminum and copper.

In the middle is my tungsten carbide ring. It's not pure tungsten carbide, because that material is really a ceramic and can't be shaped by bending or cutting like metals can. The material we call tungsten carbide is really tungsten carbide powder held together with the metal cobalt, like concrete is pebbles held together with cement. Cemented tungsten carbide is used to cut steel, and is certainly harder than almost anything I'm likely to grab - that's why it's unscratched.

The ring on the right is my new titanium one. They're all the same size, but the titanium one is much lighter than the others because it's only about a quarter as dense. This makes the Metal Guessing Game a lot more interesting, even though I don't wear the silver ring any more. This lightness, together with its resistance to corrosion, is earning titanium some inroads into the world of jewelry. Its strength also makes it a great structural material, but its Achilles' heel is that machinists hate it: its terrible friction and wear properties cause it to weld itself to cutting tools.

Cold and brittleness

You can tell a cold morning by the high-pitched crackle of ice under your feet. Have you ever broken a tool while working on your car outside in the winter? Or dropped a plastic lunch container out of the freezer and seen the corner break off? Cold and brittleness are inextricably linked in people's minds, but on the surface there's no real reason for it. I'll put on my lab coat for a moment here and go a little deeper.

Steel is the classic example. There was speculation that the Titanic sank because the iron hull had been embrittled by the frigid waters of the north Atlantic. It's true that during World War II, twelve Liberty-class cargo ships broke in half. The ensuing research uncovered the cause: the ductile-to-brittle transition in bcc metals. Steel is an example of a bcc metal (which refers to the arrangement of the atoms in the structure) and when warm it can be bent quite a bit before it breaks (it is ductile). However, at around the temperature of ice water, the tiny crystals that make up steel parts harden to the point where cracks simply separate them, instead of the crystals stretching to blunt the tip of the advancing crack. These free-running cracks then allow the part to simply break in two.


Those tiny crystals (above) are at the root of most of this behavior. As I mentioned, the atoms in each crystal are arranged in an orderly fashion, which allows them to deform in a similarly orderly fashion. Now, the amount of force it takes to deform a crystal is smaller at high temperatures. (That's why the World Trade Center buildings didn't collapse immediately when they were hit by planes: it only happened after the jet fuel fire softened and bent the steel girders.) But the amount of force needed to pry two neighboring crystals apart doesn't change. That means that when it gets cold enough, steel cracks like styrofoam instead of each crystal pulling like taffy.

What about the lunch containers that crack when they fall out of the freezer? They're not metal. It turns out that plastics have a "glass transition temperature" above which they are softer. Window glass has such a temperature too, but it's red hot; the same word is used because plastics and glasses both have a random atomic arrangement. Above the glass transition temperature, plastics and glasses respond quickly to external forces - picture a glassblower bending red hot glass. So when you drop a cold plastic tub, it can't change shape fast enough to deal with the impact and it breaks.

So maybe there's something behind the perception that everything gets brittle in the cold. Everything I've talked about here is based on the mobility of atoms, which vibrate more at higher temperatures. Those vibrations allow plastics to flow and metals to deform. And there's your materials science lesson for the day!

Bridgeport Mill: O Joyous Metal-Eraser

I learned to use this machine last week. My only question is, WHY NOT FIFTEEN YEARS AGO?

This Bridgeport mill is a manually operated milling machine with a digital position display. Conceptually a milling machine is like a power drill pointing downwards, with the ability to move the thing you're drilling up, down, left, right, etc. You bring the workpiece to the drill, and the tip cuts away any metal in its path. Using the display, you can decide when to stop cutting with an accuracy of a thousandth of an inch.

I used it tirelessly for hours, giggling like a toddler.

I spent much of my stint in graduate school in search of appropriately shaped pieces of metal so I could perform my experiments. I learned to use drill presses, bandsaws, grinders, press brakes, shears, and all manner of hand tools, but nobody ever inducted me into the secret brotherhood of mill users. I'll never look at a piece of aluminum the same way again.

Thermoelectric lighthouses

The Soviet nuclear lighthouses discussed at Dinosaurs & Robots were powered by the thermoelectric effect - my current professional field.

Thermoelectric devices use electrical power to move heat, or use the movement of heat to produce electricity. The vast majority of thermoelectric devices sold today are for cooling; they can chill something to below ambient temperature (which you can't do with a fan) and they can be made much smaller than a compressor-based refrigerator.

In the early days of thermoelectricity, however, the main interest was power generation. As early as 1961, NASA launched a satellite powered by a Radioisotope Thermoelectric Generator. It's easy to forget that radioactive materials are said to be "hot" because their temperatures are high, even when they're just sitting there. Such materials are used to heat one side of a thermoelectric device, while the other side is cooled by fins. The heat flowing through the device is converted (partially) to electricity. The Wikipedia article linked to above lists the RTGs used in those Soviet lighthouses.

Thermoelectric power generation has experienced something of a renaissance since the early 1990s, when funding from U.S. military R&D programs brought more academics into the field. Today, as we face declining world oil reserves, energy efficiency is once again on the public's mind. TEs are a leading contender, for example, among proposals to make use of the waste heat coming out of your car's tailpipe. BMW built a prototype last year.

The Mystery of Steel

This thrills my inner metallurgist. Over at Dinosaurs & Robots, they've blogged about a limited number of cars built with stainless steel bodies. They've been shiny for 70 years.

People don't think much about steel. Steel kicked off the industrial revolution in the late 1800s by allowing control over the balance between strength (resistance to permanent bending) and toughness (resistance to fracture). And that's plain carbon steel - stainless came later.

By the way, Mr. Jalopy over at D&R is a bit of a kindred spirit for me. He is, basically, ten.

Metals trivia of the day: tungsten darts

Maybe you've thrown darts before. It's an old sport, and technology doesn't have much to offer it, unlike, say, bicycling or Formula One racing. Traditionally, darts have been made of brass (an alloy of copper and zinc) and weigh 20 grams. However, more expensive darts are made mostly of tungsten. If darts can't weigh more than 20 grams in a tournament ... why make them out of a material that weighs more?The photo above shows a brass dart and a tungsten dart. The tungsten dart's barrel is smaller; its 20 grams weight takes up less space. Aha, you say: less aerodynamic drag. But no. If you're really accurate--better than I am--then you might be able to get two darts into a very small space ... like the bullseye.

And there's your metals trivia of the day.

Metallurgical curiosities, continued

This machine is sick. Its metal skin has big metal boils. Since I have a doctorate in materials, I am trying to cure it. I think I'll try hammer therapy.

Well, no, not really. The five warts on the machine are nickel "slugs". Basically they are relatively pure nickel that was spooged molten out of a nozzle onto a cold surface, where they solidified. They're made this way so they'll be easier for human beings to scoop up and carry around. I like them because they have a vaguely biological look to them, even though they're metal. It's an interesting contrast.

This is a lead airplane. Not a zeppelin, nor a paper airplane. It's made of lead (Pb) about a sixteenth of an inch thick, which I folded into the shape of a paper airplane by bending it across the edge of a desk. Lead is really soft and this wasn't too difficult to do. I was using the lead as radiation shielding for an X-ray machine I was building, and I had some extra left over.

Yeah, I like metal.

Single crystals and other reasons my job rocks

The post about metal rings got me thinking about my job. As a materials scientist, I get to melt stuff. A friend once told me "you don't have to scratch a chemist very deep to find a pyromaniac." It's no coincidence he was a chemist. Melting stuff is fun. No, it's not fun, it's AWESOME.

The other day I mentioned that tungsten has the highest melting point of any pure metal. I once had the great privilege to handle several single crystals of tungsten, each the size of a thick toothpick. Here's where I school you a little.

The metals you see around you every day are crystalline, just like diamonds. The difference is that jewelry gemstones are single crystals, whereas metal crystals are small and so well bonded together that you don't notice them. In a crystal, all the atoms are lined up in three dimensions, packed in closely like freshly racked billiard balls. By contrast, in a glassy material, the atoms are positioned randomly.

You can make single crystals of many materials by a technique called Czochralski growth, where basically you melt a bowl of the material, bring a cold "seed crystal" down in contact with its surface, and slowly pull upwards while keeping the seed cool. The molten material will solidify onto the seed in perfect alignment with the atoms that are already there. This is how the computer industry makes silicon "boules" twelve inches in diameter, later to be made into microprocessors.

At this point your scalp may be starting to sweat as you contemplate the possibility of twelve-inch diamonds. Relax: there is no such thing as molten diamond. It goes straight from solid to gas, like moth balls and dry ice. There's a similar problem with tungsten: the only kind of bowl you can melt tungsten in would be either diamond (expensive) or, well, cold tungsten. Instead, they use a different technique. They make a rod of ordinary tungsten, and then melt a little section in the middle. They move this molten section slowly along the length of the rod, and usually eventually one of the solidifying crystals will get bigger until it fills the whole width of the rod. This is quite difficult at 6200 degrees Fahrenheit.

In my current job, I use a similar technique--a quartz tube with a moving heater around it and an alloy inside--to make nearly perfect crystals of my material. There are usually at least two or three crystals at any point along the length of the thing, but still: it's a two pound metal crystal, an inch around and eight inches long. It gives me a gut thrill every time I handle one, and I think of the perfect crystalline order of tens of millions of atoms standing in a line.

It's a coincidence, probably, that these objects are shaped like metallurgical phallic symbols. Alloy furnaces are the hairy ball sacks of materials science. It's complete command over nature, a triumph of empirical rationalism, and it gives me a hardon once in a while.

That might seem perverse, but I think it's common. Accountants and MBAs get a hardon for large sums of money. Engineers, for metals and big power and, well, big engines. Military guys, for big weapons, probably. HU-AH.

Other amazing things I have held in my hands: a fist-sized chunk of "machinable tungsten" (really tungsten powder cemented together with rhenium) which was astonishingly heavy; a fuel injector plunger coated with "near-frictionless carbon", which provides a sliding friction coefficient of 0.001 in dry air; a four-inch-wide disc of boron carbide, one of the hardest materials known; and more.

Meet Uncle Tungsten's hard-living brother, Tungsten Carbide

I have a new ring that I like to play with and show to people. I wanted tungsten but I ended up with tungsten carbide. Read on.

For many years I wore two rings--a plain silver band on my right hand and my plain platinum wedding band on my left. I'm a materials scientist by trade, so occasionally I would pass these around at conferences and challenge people to identify the metals.

People are used to the relative heft of aluminum and steel; steel is three times as dense as aluminum. Materials scientists play with a lot of different metals, but one of them thought the silver ring was aluminum and the platinum ring was steel, simply because of their weights. (Never mind how absurd it would be to wear aluminum and steel rings. Materials scientists sometimes come up short in the social graces.) Platinum is indeed twice as dense as silver. But the thing is, silver is even denser than steel. Platinum is seriously heavy stuff. Lacking a known reference, the weigh-it-in-your-hand judgement can be way off.

A year or two ago I started seeing rings with dark gray inlaid bands. I found out this was tungsten - and immediately wanted it. In addition to being almost as dense as platinum, tungsten has the highest melting point of any pure metal. (So when spontaneous human combustion catches up with me, they'll be able to salvage my jewelry.)

This month I got my chance. It was near my birthday, and my wife brought me to a jewelry store to show me a diamond ring. Which, it turned out, cost half what my car did. But they also had a heap of plain metal bands. One was polished and dark grey - not just a tungsten inset, but all tungsten. Happy birthday to me! When I got it home I happened to see writing inside it and found that it's really tungsten carbide, but I don't feel too badly about that. Tungsten carbide is the material used to cut other metals: it makes up machine tool cutting bits that reach 1000 degrees C and suffer tremendous forces. These tools (and probably my ring) are actually tungsten carbide powder cemented together with about 5 volume percent cobalt, but I'm not complaining. So my new ring is essentially unscratchable. I'm unlikely to grab anything harder than it is.

I'm no longer wearing the silver band, though maybe I should be. There were other interesting rings in that heap, and I'm tempted to start wearing a metallurgical display case on my hands. The titanium rings were super-light (density less than half that of silver) and actually rather pretty. Some had a rainbow oxide treatment. Titanium is a great lightweight structural metal (turbine engine blades, etc) but it gives a lousy friction and wear surface. So I'm OK with tungsten carbide for the time being.