The Disappearing Spoon Part 8

Above (and Beyond) the Periodic Table

There's a conundrum near the fringes of the periodic table. Highly radioactive elements are always scarce, so you'd think, intuitively, the element that falls apart the most easily would also be the most scarce. And the element that is effaced most quickly and thoroughly whenever it appears in the earth's crust, ultra-fragile francium, is indeed rare. Francium winks out of existence on a timescale quicker than any other natural atom-yet one element is even rarer than francium. It's a paradox, and resolving the paradox actually requires leaving behind the comfortable confines of the periodic table. It requires setting out for what nuclear physicists consider their New World, their America to conquer-the "island of stability"-which is their best and perhaps only hope for extending the table beyond its current limitations.

As we know, 90 percent of particles in the universe are hydrogen, and the other 10 percent are helium. Everything else, including six million billion billion kilos of earth, is a cosmic rounding error. And in that six million billion billion kilos, the total amount of astatine, the scarcest natural element, is one stupid ounce. To put that into some sort of (barely) comprehensible scope, imagine that you lost your Buick Astatine in an immense parking garage and you have zero idea where it is. Imagine the tedium of walking down every row on every level past every s.p.a.ce, looking for your vehicle. To mimic hunting for astatine atoms inside the earth, that parking garage would have to be about 100 million s.p.a.ces wide, have 100 million rows, and be 100 million stories high. And there would have to be 160 identical garages just as big-and in all those buildings, there'd be just one Astatine. You'd be better off walking home.

If astatine is so rare, it's natural to ask how scientists ever took a census of it. The answer is, they cheated a little. Any astatine present in the early earth has long since disintegrated radioactively, but other radioactive elements sometimes decay into astatine after they spit out alpha or beta particles. By knowing the total amount of the parent elements (usually elements near uranium) and calculating the odds that each of those will decay into astatine, scientists can ring up some plausible numbers for how many astatine atoms exist. This works for other elements, too. For instance, at least twenty to thirty ounces of astatine's near neighbor on the periodic table, francium, exist at any moment.

Funnily enough, astatine is at the same time far more robust than francium. If you had a million atoms of the longest-lived type of astatine, half of them would disintegrate in four hundred minutes. A similar sample of francium would hang on for just twenty minutes. Francium is so fragile it's basically useless, and even though there's (barely) enough of it in the earth for chemists to detect it directly, no one will ever herd enough atoms of it together to make a visible sample. If they did, it would be so intensely radioactive it would murder them immediately. (The current flash-mob record for francium is ten thousand atoms.) No one will likely ever produce a visible sample of astatine either, but at least it's good for something-as a quick-acting radioisotope in medicine. In fact, after scientists-led by our old friend Emilio Segre-identified astatine in 1939, they injected a sample into a guinea pig to study it. Because astatine sits below iodine on the periodic table, it acts like iodine in the body and so was selectively filtered and concentrated by the rodent's thyroid gland. Astatine remains the only element whose discovery was confirmed by a nonprimate.

The odd reciprocity between astatine and francium begins in their nuclei. There, as in all atoms, two forces struggle for dominance: the strong nuclear force (which is always attractive) and the electrostatic force (which can repel particles). Though the most powerful of nature's four fundamental forces, the strong nuclear force has ridiculously short arms. Think Tyrannosaurus rex Tyrannosaurus rex. If particles stray more than a few trillionths of an inch apart, the strong force is impotent. For that reason, it rarely comes into play outside nuclei and black holes. Yet within its range, it's a hundred times more muscular than the electrostatic force. That's good, because it keeps protons and neutrons bound together instead of letting the electrostatic force wrench nuclei apart.

When you get to nuclei the size of astatine and francium, the limited reach really catches up with the strong force, and it has trouble binding all the protons and neutrons together. Francium has eighty-seven protons, none of which want to touch. Its 130-odd neutrons buffer the positive charges well but also add so much bulk that the strong force cannot reach all the way across a nucleus to quell civil strife. This makes francium (and astatine, for similar reasons) highly unstable. And it stands to reason that adding more protons would increase electric repulsion, making atoms heavier than francium even weaker.

That's only sort of correct, though. Remember that Maria Goeppert-Mayer ("S.D. Mother Wins n.o.bel Prize") developed a theory about long-lived "magic" elements-atoms with two, eight, twenty, twenty-eight, etc., protons or neutrons that were extra-stable. Other numbers of protons or neutrons, such as ninety-two, also form compact and fairly stable nuclei, where the short-leashed strong force can tighten its grip on protons. That's why uranium is more stable than either astatine or francium, despite being heavier. As you move down the periodic table element by element, then, the struggle between the strong nuclear and electrostatic forces resembles a plummeting stock market ticker, with an overall downward trend in stability, but with many wiggles and fluctuations as one force gains the upper hand, then the other.*

Based on this prevailing pattern, scientists a.s.sumed that the elements beyond uranium would asymptotically approach a life span of 0.0. But as they groped forward with the ultraheavy elements in the 1950s and 1960s, something unexpected happened. In theory, magic numbers extend until infinity, and it turned out that there was a quasi-stable nucleus after uranium, at element 114. And instead of it being fractionally more stable, scientists at (where else?) the University of California at Berkeley calculated that 114 might survive orders of magnitude longer than the ten or so heavy elements preceding it. Given the dismally short life span of heavy elements (microseconds at best), this was a wild, counterintuitive idea. Packing neutrons and protons onto most man-made elements is like packing on explosives, since you're putting more stress on the nucleus. Yet with element 114, packing on more TNT seemed to steady steady the bomb. Just as strangely, elements such as 112 and 116 seemed (on paper at least) to get horseshoes-and-kisses benefits from having close to 114 protons. Even being around that quasi-magic number calmed them. Scientists began calling this cl.u.s.ter of elements the island of stability. the bomb. Just as strangely, elements such as 112 and 116 seemed (on paper at least) to get horseshoes-and-kisses benefits from having close to 114 protons. Even being around that quasi-magic number calmed them. Scientists began calling this cl.u.s.ter of elements the island of stability.

A whimsical map of the fabled "island of stability," a clump of superheavy elements that scientists hope will allow them to extend the periodic table far past its present bounds. Notice the stable lead (Pb) continent of the main-body periodic table, the watery trench of unstable elements, and the small, semi-stable peaks at thorium and uranium before the sea opens up. (Yuri Oganessian, Joint Inst.i.tute for Nuclear Research, Dubna, Russia) Charmed by their own metaphor, and flattering themselves as brave explorers, scientists began preparing to conquer the island. They spoke of finding an elemental "Atlantis," and some, like old-time sailors, even produced sepia "charts" of unknown nucleic seas. (You'd half expect to see krakens drawn in the waters.) And for decades now, attempts to reach that oasis of superheavy elements have made up one of the most exciting fields of physics. Scientists haven't reached land yet (to get truly stable, doubly magic elements, they need to figure out ways to add more neutrons to their targets), but they're in the island's shallows, paddling around for a harbor.

Of course, an island of stability implies a stretch of submerged stability-a stretch centered on francium. Element eighty-seven is stranded between a magic nucleus at eighty-two and a quasi-stable nucleus at ninety-two, and it's all too tempting for its neutrons and protons to abandon ship and swim. In fact, because of the poor structural foundation of its nucleus, francium is not only the least stable natural element, it's less stable than every synthetic element up to 104, the ungainly rutherfordium. If there's a "trench of instability," francium is gargling bubbles at the bottom of the Mariana.

Still, it's more abundant than astatine. Why? Because many radioactive elements around uranium happen to decay into francium as they disintegrate. But francium, instead of doing the normal alpha decay and thereby converting itself (through the loss of two protons) into astatine, decides more than 99.9 percent of the time to relieve the pressure in its nucleus by undergoing beta decay and becoming radium. Radium then undergoes a cascade of alpha decays that leap over astatine. In other words, the path of many decaying atoms leads to a short layover on francium-hence the twenty to thirty ounces of it. At the same time, francium shuttles atoms away from astatine, causing astatine to remain rare. Conundrum solved.

Now that we've plumbed the trenches, what about that island of stability? It's doubtful that chemists will ever synthesize all the elements up to very high magic numbers. But perhaps they can synthesize a stable element 114, then 126, then go from there. Some scientists believe, too, that adding electrons to extra-heavy atoms can stabilize their nuclei-the electrons might act as springs and shocks to absorb the energy that atoms normally dedicate to tearing themselves apart. If that's so, maybe elements in the 140s, 160s, and 180s are possible. The island of stability would become a chain of islands. These stable islands would get farther apart, but perhaps, like Polynesian canoers, scientists can cross some wild distances on the new periodic archipelago.

The thrilling part is that those new elements, instead of being just heavier versions of what we already know, could have novel properties (remember how lead emerges from a lineage of carbon and silicon). According to some calculations, if electrons can tame superheavy nuclei and make them more stable, those nuclei can manipulate electrons, too-in which case, electrons might fill the atoms' sh.e.l.ls and orbitals in a different order. Elements whose address on the table should make them normal heavy metals might fill in their octets early and act like metallic n.o.ble gases instead.

Not to tempt the G.o.ds of hubris, but scientists already have names for those hypothetical elements. You may have noticed that the extra-heavy elements along the bottom of the table get three letters instead of two and that all of them start with u. u. Once again, it's the lingering influence of Latin and Greek. As yet undiscovered element 119, Uue, is ununennium; element 122, Ubb, is unbibium; Once again, it's the lingering influence of Latin and Greek. As yet undiscovered element 119, Uue, is ununennium; element 122, Ubb, is unbibium;* and so on. Those elements will receive "real" names if they're ever made, but for now scientists can jot them down-and mark off other elements of interest, such as magic number 184, unoctquadium-with Latin subst.i.tutes. (And thank goodness for them. With the impending death of the binomial species system in biology-the system that gave us and so on. Those elements will receive "real" names if they're ever made, but for now scientists can jot them down-and mark off other elements of interest, such as magic number 184, unoctquadium-with Latin subst.i.tutes. (And thank goodness for them. With the impending death of the binomial species system in biology-the system that gave us Felis catus Felis catus for the house cat is gradually being replaced with chromosomal DNA "bar codes," so good-bye for the house cat is gradually being replaced with chromosomal DNA "bar codes," so good-bye h.o.m.o sapiens, h.o.m.o sapiens, the knowing ape, h.e.l.lo TCATCGGTCATTGG...-the the knowing ape, h.e.l.lo TCATCGGTCATTGG...-the u u elements remain about the only holdouts of once-dominant Latin in science. elements remain about the only holdouts of once-dominant Latin in science.*) So how far can this island-hopping extend? Can we watch little volcanoes rise beneath the periodic table forever, watch it expand and stretch down to the fittingly wide Eee, ennennennium, element 999, or even beyond? Sigh, Sigh, no. Even if scientists figure out how to glue extra-heavy elements together, and even if they land smack on the farther-off islands of stability, they'll almost certainly skid right off into the messy seas. no. Even if scientists figure out how to glue extra-heavy elements together, and even if they land smack on the farther-off islands of stability, they'll almost certainly skid right off into the messy seas.

The reason traces back to Albert Einstein and the biggest failure of his career. Despite the earnest belief of most of his fans, Einstein did not win his n.o.bel Prize for the theory of relativity, special or general. He won for explaining a strange effect in quantum mechanics, the photoelectric effect. His solution provided the first real evidence that quantum mechanics wasn't a crude stopgap for justifying anomalous experiments, but actually corresponds to reality. And the fact that Einstein came up with it is ironic for two reasons. One, as he got older and crustier, Einstein came to distrust quantum mechanics. Its statistical and deeply probabilistic nature sounded too much like gambling to him, and it prompted him to object that "G.o.d does not play dice with the universe." He was wrong, and it's too bad that most people have never heard the rejoinder by Niels Bohr: "Einstein! Stop telling G.o.d what to do."

Second, although Einstein spent his career trying to unify quantum mechanics and relativity into a coherent and svelte "theory of everything," he failed. Not completely, however. Sometimes when the two theories touch, they complement each other brilliantly: relativistic corrections of the speed of electrons help explain why mercury (the element I'm always looking out for) is a liquid and not the expected solid at room temperature. And no one could have created his namesake element, number ninety-nine, einsteinium, without knowledge of both theories. But overall, Einstein's ideas on gravity, the speed of light, and relativity don't quite fit with quantum mechanics. In some cases where the two theories come into contact, such as inside black holes, all the fancy equations break down.

That breakdown could set limits on the periodic table. To return to the electron-planet a.n.a.logy, just as Mercury zips around the sun every three months while Neptune drags on for 165 years, inner electrons...o...b..t much more quickly around a nucleus than electrons in outer sh.e.l.ls. The exact speed depends on the ratio between the number of protons present and alpha, the fine structure constant discussed last chapter. As that ratio gets closer and closer to one, electrons fly closer and closer to the speed of light. But remember that alpha is (we think) fixed at 1/137 or so. Beyond 137 protons, the inner electrons would seem to be going faster than the speed of light-which, according to Einstein's relativity theory, can never happen.

This hypothetically last element, 137, is often called "feynmanium," after Richard Feynman, the physicist who first noticed this pickle. He's also the one who called alpha "one of the great d.a.m.n mysteries of the universe," and now you can see why. As the irresistible force of quantum mechanics meets the immovable object of relativity just past feynmanium, something has to give. No one knows what.

Some physicists, the kind of people who think seriously about time travel, think that relativity may have a loophole that allows special (and, conveniently, un.o.bservable) particles called tachyons to go faster than light's 186,000 miles per second. The catch with tachyons is that they may move backward in time. So if super-chemists someday create feynmanium-plus-one, untrioctium, would its inner electrons become time travelers while the rest of the atom sits pat? Probably not. Probably the speed of light simply puts a hard cap on the size of atoms, which would obliterate those fanciful islands of stability as thoroughly as A-bomb tests did coral atolls in the 1950s.

So does that mean the periodic table will be kaput soon? Fixed and frozen, a fossil?

No, no, and no again.

If aliens ever land and park here, there's no guarantee we'll be able to communicate with them, even going beyond the obvious fact they won't speak "Earth." They might use pheromones or pulses of light instead of sounds; they might also be, especially on the off off chance they're not made of carbon, poisonous to be around. Even if we do break into their minds, our primary concerns-love, G.o.ds, respect, family, money, peace-may not register with them. About the only things we can drop in front of them and be sure they'll grasp are numbers like pi and the periodic table.

Of course, that should be the properties properties of the periodic table, since the standard castles-with-turrets look of our table, though chiseled into the back of every extant chemistry book, is just one possible arrangement of elements. Many of our grandfathers grew up with quite a different table, one just eight columns wide all the way down. It looked more like a calendar, with all the rows of the transition metals triangled off into half boxes, like those unfortunate 30s and 31s in awkwardly arranged months. Even more dubiously, a few people shoved the lanthanides into the main body of the table, creating a crowded mess. of the periodic table, since the standard castles-with-turrets look of our table, though chiseled into the back of every extant chemistry book, is just one possible arrangement of elements. Many of our grandfathers grew up with quite a different table, one just eight columns wide all the way down. It looked more like a calendar, with all the rows of the transition metals triangled off into half boxes, like those unfortunate 30s and 31s in awkwardly arranged months. Even more dubiously, a few people shoved the lanthanides into the main body of the table, creating a crowded mess.

No one thought to give the transition metals a little more s.p.a.ce until Glenn Seaborg and his colleagues at (wait for it) the University of California at Berkeley made over the entire periodic table between the late 1930s and early 1960s. It wasn't just that they added elements. They also realized that elements like actinium didn't fit into the scheme they'd grown up with. Again, it sounds odd to say, but chemists before this didn't take periodicity seriously enough. They thought the lanthanides and their annoying chemistry were exceptions to the normal periodic table rules-that no elements below the lanthanides would ever bury electrons and deviate from transition-metal chemistry in the same way. But the lanthanide chemistry does repeat. It has to: that's the categorical imperative of chemistry, the the property of elements the aliens would recognize. And they'd recognize as surely as Seaborg did that the elements diverge into something new and strange right after actinium, element eighty-nine. property of elements the aliens would recognize. And they'd recognize as surely as Seaborg did that the elements diverge into something new and strange right after actinium, element eighty-nine.

Actinium was the key element in giving the modern periodic table its shape, since Seaborg and his colleagues decided to cleave all the heavy elements known at the time-now called the actinides, after their first brother-and cordon them off at the bottom of the table. As long as they were moving those elements, they decided to give the transition metals more elbow room, too, and instead of cramming them into triangles, they added ten columns to the table. This blueprint made so much sense that many people copied Seaborg. It took a while for the hard-liners who preferred the old table to die off, but in the 1970s the periodic calendar finally shifted to become the periodic castle, the bulwark of modern chemistry.

But who says that's the ideal shape? The columnar form has dominated since Mendeleev's day, but Mendeleev himself designed thirty different periodic tables, and by the 1970s scientists had designed more than seven hundred variations. Some chemists like to snap off the turret on one side and attach it to the other, so the periodic table looks like an awkward staircase. Others fuss with hydrogen and helium, dropping them into different columns to emphasize that those two non-octet elements get themselves into strange situations chemically.

Really, though, once you start playing around with the periodic table's form, there's no reason to limit yourself to rectilinear shapes.* One clever modern periodic table looks like a honeycomb, with each hexagonal box spiraling outward in wider and wider arms from the hydrogen core. Astronomers and astrophysicists might like the version where a hydrogen "sun" sits at the center of the table, and all the other elements...o...b..t it like planets with moons. Biologists have mapped the periodic table onto helixes, like our DNA, and geeks have sketched out periodic tables where rows and columns double back on themselves and wrap around the paper like the board game Parcheesi. Someone even holds a U.S. patent (#6361324) for a pyramidal Rubik's Cube toy whose twistable faces contain elements. One clever modern periodic table looks like a honeycomb, with each hexagonal box spiraling outward in wider and wider arms from the hydrogen core. Astronomers and astrophysicists might like the version where a hydrogen "sun" sits at the center of the table, and all the other elements...o...b..t it like planets with moons. Biologists have mapped the periodic table onto helixes, like our DNA, and geeks have sketched out periodic tables where rows and columns double back on themselves and wrap around the paper like the board game Parcheesi. Someone even holds a U.S. patent (#6361324) for a pyramidal Rubik's Cube toy whose twistable faces contain elements.

Musically inclined people have graphed elements onto musical staffs, and our old friend William Crookes, the spiritualist seeker, designed two fittingly fanciful periodic tables, one that looked like a lute and another like a pretzel. My own favorite tables are a pyramid-shaped one-which very sensibly gets wider row by row and demonstrates graphically where new orbitals arise and how many more elements fit themselves into the overall system-and a cutout one with twists in the middle, which I can't quite figure out but enjoy because it looks like a Mobius strip.

We don't even have to limit periodic tables to two dimensions anymore. The negatively charged antiprotons that Segre discovered in 1955 pair very nicely with antielectrons (i.e., positrons) to form anti-hydrogen atoms. In theory, every other anti-element on the antiperiodic table might exist, too. And beyond just that looking-gla.s.s version of the regular periodic table, chemists are exploring new forms of matter that could multiply the number of known "elements" into the hundreds if not thousands.

First are superatoms. These cl.u.s.ters-between eight and one hundred atoms of one element-have the eerie ability to mimic single atoms of different elements. For instance, thirteen aluminium atoms grouped together in the right way do a killer bromine: the two ent.i.ties are indistinguishable in chemical reactions. This happens despite the cl.u.s.ter being thirteen times larger than a single bromine atom and despite aluminium being nothing like the lacrimatory poison-gas staple. Other combinations of aluminium can mimic n.o.ble gases, semiconductors, bone materials like calcium, or elements from pretty much any other region of the periodic table.

The cl.u.s.ters work like this. The atoms arrange themselves into a three-dimensional polyhedron, and each atom in it mimics a proton or neutron in a collective nucleus. The caveat is that electrons can flow around inside this soft nucleic blob, and the atoms share the electrons collectively. Scientists wryly call this state of matter "jellium." Depending on the shape of the polyhedron and the number of corners and edges, the jellium will have more or fewer electrons to farm out and react with other atoms. If it has seven, it acts like bromine or a halogen. If four, it acts like silicon or a semiconductor. Sodium atoms can also become jellium and mimic other elements. And there's no reason to think that still other elements cannot imitate other elements, or even all the elements imitate all the other elements-an utterly Borgesian mess. These discoveries are forcing scientists to construct parallel periodic tables to cla.s.sify all the new species, tables that, like transparencies in an anatomy textbook, must be layered on top of the periodic skeleton.

Weird as jellium is, the cl.u.s.ters at least resemble normal atoms. Not so with the second way of adding depth to the periodic table. A quantum dot is a sort of holographic, virtual atom that nonetheless obeys the rules of quantum mechanics. Different elements can make quantum dots, but one of the best is indium. It's a silvery metal, a relative of aluminium, and lives just on the borderland between metals and semiconductors.

Scientists start construction of a quantum dot by building a tiny Devils Tower, barely visible to the eye. Like geologic strata, this tower consists of layers-from the bottom up, there's a semiconductor, a thin layer of an insulator (a ceramic), indium, a thicker layer of a ceramic, and a cap of metal on top. A positive charge is applied to the metal cap, which attracts electrons. They race upward until they reach the insulator, which they cannot flow through. However, if the insulator is thin enough, an electron-which at its fundamental level is just a wave-can pull some voodoo quantum mechanical stuff and "tunnel" through to the indium.

At this point, scientists snap off the voltage, trapping the orphan electron. Indium happens to be good at letting electrons flow around between atoms, but not so good that an electron disappears inside the layer. The electron sort of hovers instead, mobile but discrete, and if the indium layer is thin enough and narrow enough, the thousand or so indium atoms band together and act like one collective atom, all of them sharing the trapped electron. It's a superorganism. Put two or more electrons in the quantum dot, and they'll take on opposite spins inside the indium and separate in oversized orbitals and sh.e.l.ls. It's hard to overstate how weird this is, like getting the giant atoms of the Bose-Einstein condensate but without all the fuss of cooling things down to billionths of a degree above absolute zero. And it isn't an idle exercise: the dots show enormous potential for next-generation "quantum computers," because scientists can control, and therefore perform calculations with, individual electrons, a much faster and cleaner procedure than channeling billions of electrons through semiconductors in Jack Kilby's fifty-year-old integrated circuits.

Nor will the periodic table be the same after quantum dots. Because the dots, also called pancake atoms, are so flat, the electron sh.e.l.ls are different than usual. In fact, so far the pancake periodic table looks quite different than the periodic table we're used to. It's narrower, for one thing, since the octet rule doesn't hold. Electrons fill up sh.e.l.ls more quickly, and nonreactive n.o.ble gases are separated by fewer elements. That doesn't stop other, more reactive quantum dots from sharing electrons and bonding with other nearby quantum dots to form... well, who knows what the h.e.l.l they are. Unlike with superatoms, there aren't any real-world elements that form tidy a.n.a.logues to quantum-dot "elements."

In the end, though, there's little doubt that Seaborg's table of rows and turrets, with the lanthanides and actinides like moats along the bottom, will dominate chemistry cla.s.ses for generations to come. It's a good combination of easy to make and easy to learn. But it's a shame more textbook publishers don't balance Seaborg's table, which appears inside the front cover of every chemistry book, with a few of the more suggestive periodic table arrangements inside the back cover: 3D shapes that pop and buckle on the page and that bend far-distant elements near each other, sparking some link in the imagination when you finally see them side by side. I wish very much that I could donate $1,000 to some nonprofit group to support tinkering with wild new periodic tables based on whatever organizing principles people can imagine. The current periodic table has served us well so far, but reenvisioning and recreating it is important for humans (some of us, at least). Moreover, if aliens ever do descend, I want them to be impressed with our ingenuity. And maybe, just maybe, for them to see some shape they recognize among our collection.

Then again, maybe our good old boxy array of rows and turrets, and its marvelous, clean simplicity, will grab them. And maybe, despite all their alternative arrangements of elements, and despite all they know about superatoms and quantum dots, they'll see something new in this table. Maybe as we explain how to read the table on all its different levels, they'll whistle (or whatever) in real admiration-staggered at all we human beings have managed to pack into our periodic table of the elements.

ACKNOWLEDGMENTS AND THANKS.

I would first like to thank my dear ones. My parents, who got me writing, and never asked too often what exactly I was going to do with myself once I'd started. My lovely Paula, who held my hand. My siblings, Ben and Becca, who taught me mischief. All my other friends and family from South Dakota and around the country, who supported me and got me out of the house. And finally my various teachers and professors, who first related many of the stories here, without realizing they were doing something so valuable.

I would furthermore like to thank my agent, Rick Broadhead, who believed that this project was a swell idea and that I was the one to write it. I owe a lot as well to my editor at Little, Brown, John Parsley, who saw what this book could be and helped shape it. Also invaluable were others at and around Little, Brown, including Cara Eisenpress, Sarah Murphy, Peggy Freudenthal, Barbara Jatkola, and many unnamed others who helped design and improve this book.

I offer thanks, too, to the many, many people who contributed to individual chapters and pa.s.sages, either by fleshing out stories, helping me hunt down information, or offering their time to explain something to me. These include Stefan Fajans; Theodore Gray of www.periodictable.com; Barbara Stewart at Alcoa; Jim Marshall of the University of North Texas; Eric Scerri of the University of California at Los Angeles; Chris Reed at the University of California, Riverside; Nadia Izakson; the communications team at Chemical Abstracts Service; and the staff and science reference librarians at the Library of Congress. If I've left anyone off this list, my apologies. I remain thankful, if embarra.s.sed.

Finally, I owe a special debt of grat.i.tude to Dmitri Mendeleev, Julius Lother Meyer, John Newlands, Alexandre-Emile Beguyer de Chancourtois, William Odling, Gustavus Hinrichs, and the other scientists who developed the periodic table-as well as thousands of other scientists who contributed to these fascinating stories about the elements.

NOTES AND E ERRATA.

Introduction.

"literature, poison forensics, and psychology": Another topic I learned about via mercury was meteorology. The final peal of the death knell of alchemy sounded on the day after Christmas in 1759, when two Russian scientists, trying to see how cold they could get a mixture of snow and acid, accidentally froze the quicksilver in their thermometer. This was the first recorded case of solid Hg, and with that evidence, the alchemists' immortal fluid was banished to the realm of normal matter. Another topic I learned about via mercury was meteorology. The final peal of the death knell of alchemy sounded on the day after Christmas in 1759, when two Russian scientists, trying to see how cold they could get a mixture of snow and acid, accidentally froze the quicksilver in their thermometer. This was the first recorded case of solid Hg, and with that evidence, the alchemists' immortal fluid was banished to the realm of normal matter.

Lately mercury has been politicized as well, as activists in the United States have campaigned vigorously against the (totally unfounded) dangers of mercury in vaccines.

1. Geography Is Destiny.

"anything but a pure element": Two scientists observed the first evidence for helium (an unknown spectral line, in the yellow range) during an eclipse in 1868-hence the element's name, from Two scientists observed the first evidence for helium (an unknown spectral line, in the yellow range) during an eclipse in 1868-hence the element's name, from helios, helios, Greek for "sun." The element was not isolated on earth until 1895, through the careful isolation of helium from rocks. (For more on this, see Greek for "sun." The element was not isolated on earth until 1895, through the careful isolation of helium from rocks. (For more on this, see chapter 17 chapter 17.) For eight years, helium was thought to exist on earth in minute quant.i.ties only, until miners found a huge underground cache in Kansas in 1903. They had tried to light the gas shooting out of a vent in the ground on fire, but it wouldn't catch.

"only the electrons matter": To reiterate the point about atoms being mostly empty s.p.a.ce, Allan Blackman, a chemist at the University of Otago in New Zealand, wrote in the January 28, 2008, To reiterate the point about atoms being mostly empty s.p.a.ce, Allan Blackman, a chemist at the University of Otago in New Zealand, wrote in the January 28, 2008, Otago Daily Times: Otago Daily Times: "Consider the most dense known element, iridium; a sample of this the size of a tennis ball would weigh just over 3 kilograms [6.6 pounds].... Let's a.s.sume that we could somehow pack the iridium nuclei together as tight as we possibly could, thereby eliminating most of that empty s.p.a.ce.... A tennis b.a.l.l.sized sample of this compacted material would now weigh an astonishing seven trillion tonnes [7.7 trillion U.S. tons]." "Consider the most dense known element, iridium; a sample of this the size of a tennis ball would weigh just over 3 kilograms [6.6 pounds].... Let's a.s.sume that we could somehow pack the iridium nuclei together as tight as we possibly could, thereby eliminating most of that empty s.p.a.ce.... A tennis b.a.l.l.sized sample of this compacted material would now weigh an astonishing seven trillion tonnes [7.7 trillion U.S. tons]."

As a footnote to this footnote, no one really knows whether iridium is the densest element. Its density is so close to osmium's that scientists cannot distinguish between them, and in the past few decades they've traded places as king of the mountain. Osmium is on top at the moment.

"every quibbling error": For more detailed portraits of Lewis and Nernst (and many other characters, such as Linus Pauling and Fritz Haber), I highly recommend For more detailed portraits of Lewis and Nernst (and many other characters, such as Linus Pauling and Fritz Haber), I highly recommend Cathedrals of Science: The Personalities and Rivalries That Made Modern Chemistry Cathedrals of Science: The Personalities and Rivalries That Made Modern Chemistry by Patrick Coffey. It's a personality-driven account of the most important era in modern chemistry, between about 1890 and 1930. by Patrick Coffey. It's a personality-driven account of the most important era in modern chemistry, between about 1890 and 1930.

"most colorful history on the periodic table":Other facts about antimony: 1. Much of our knowledge of alchemy and antimony comes from a 1604 book, The Triumphal Chariot of Antimony The Triumphal Chariot of Antimony, written by Johann Tholde. To give his book a publicity boost, Tholde claimed he'd merely translated it from a 1450 text written by a monk, Basilius Valentinus. Fearing persecution for his beliefs, Valentinus had supposedly hidden the text in a pillar in his monastery. It remained hidden until a "miraculous thunderbolt" split the pillar in Tholde's time and allowed him to discover the ma.n.u.script.

2. Although many did call antimony a hermaphrodite, others insisted it was the essence of femininity-so much so that the alchemical symbol for antimony, , became the general symbol for "female." , became the general symbol for "female."

3. In the 1930s in China, a poor province made do with what it had and decided to make money from antimony, about the only local resource. But antimony is soft, easily rubbed away, and slightly toxic, all of which makes for poor coins, and the government soon withdrew them. Though worth just fractions of a cent then, these coins fetch thousands of dollars from collectors today.

2. Near Twins and Black Sheep.

"really wrote Shakespeare's plays": A simpler but less colorful definition of A simpler but less colorful definition of honorificabilitudinitatibus honorificabilitudinitatibus is "with honorableness." The Bacon anagram for the word is "Hi ludi, F. Baconis nati, tuiti orbi," which translates to "These plays, born of F[rancis] Bacon, are preserved for the world." is "with honorableness." The Bacon anagram for the word is "Hi ludi, F. Baconis nati, tuiti orbi," which translates to "These plays, born of F[rancis] Bacon, are preserved for the world."

"anaconda runs 1,185 letters": There's some confusion over the longest word to appear in There's some confusion over the longest word to appear in Chemical Abstracts Chemical Abstracts. Many people list the tobacco mosaic virus protein, C785H1220N212O248S2, but a substantial number instead list "tryptophan synthetase a protein," a relative of the chemical that people (wrongly) suppose makes them sleepy when they eat turkey (that's an urban legend). The tryptophan protein, C1289H2051N343O375S8, runs 1,913 letters, over 60 percent longer than the mosaic virus protein, and numerous sources-some editions of Guinness World Records Guinness World Records, the Urban Dictionary (www.urbandictionary.com), Mrs. Byrne's Dictionary of Unusual, Obscure, and Preposterous Words Mrs. Byrne's Dictionary of Unusual, Obscure, and Preposterous Words-all list tryptophan as the champ. But after spending hours in the dimly lit stacks of the Library of Congress, I never located the tryptophan molecule in Chemical Abstracts Chemical Abstracts. It just doesn't seem to have appeared in its full, spelled-out form. To be doubly sure, I hunted down the academic paper that announced the decoding of the tryptophan protein (which was separate from the Chemical Abstracts Chemical Abstracts listing), and there the authors chose to abbreviate the amino acid sequence. So its full name has never appeared in print as far as I can tell, which probably explains why listing), and there the authors chose to abbreviate the amino acid sequence. So its full name has never appeared in print as far as I can tell, which probably explains why Guinness Guinness later rescinded the listing for it as the longest word. later rescinded the listing for it as the longest word.

I did manage to track down listings for the mosaic virus, which is spelled out twice-first on page 967F of a brownish volume called Chemical Abstracts Formula Index, Jan.June 1964, Chemical Abstracts Formula Index, Jan.June 1964, then on page 6717F of then on page 6717F of Chemical Abstracts 7th Coll. Formulas, C Chemical Abstracts 7th Coll. Formulas, C23H32Z, 5665, 19621966. Both books are compendiums that collect data for all the scholarly chemistry papers published between the dates on their covers. That means, contra other references to the world's longest word (especially on the Web), the mosaic virus listing appeared only when those tomes came out in 1964 and 1966 and not in 1972.

There's more: the tryptophan paper came out in 1964, and there are other molecules listed in that 19621966 Chemical Abstracts Chemical Abstracts compendium with more Cs, Hs, Ns, Os, and Ss than the tobacco mosaic virus. So why aren't they spelled out? Because those papers appeared after 1965, the year Chemical Abstracts Service, the company in Ohio that collects all this data, overhauled its system for naming new compounds and began discouraging excessively eye-glazing names. But so why did they bother spelling out the tobacco mosaic virus protein in a 1966 compendium? It could have been chopped down but was grandfathered in. And to throw in one more twist, the original 1964 tobacco mosaic virus paper was in German. But compendium with more Cs, Hs, Ns, Os, and Ss than the tobacco mosaic virus. So why aren't they spelled out? Because those papers appeared after 1965, the year Chemical Abstracts Service, the company in Ohio that collects all this data, overhauled its system for naming new compounds and began discouraging excessively eye-glazing names. But so why did they bother spelling out the tobacco mosaic virus protein in a 1966 compendium? It could have been chopped down but was grandfathered in. And to throw in one more twist, the original 1964 tobacco mosaic virus paper was in German. But Chemical Abstracts Chemical Abstracts is an English-language doc.u.ment, in the fine reference-work tradition of Samuel Johnson and the is an English-language doc.u.ment, in the fine reference-work tradition of Samuel Johnson and the OED, OED, and it printed the name not to show off but to propagate knowledge, so it sure counts. and it printed the name not to show off but to propagate knowledge, so it sure counts.

Whew.

By the way, I owe Eric Shively, Crystal Poole Bradley, and especially Jim Corning at Chemical Abstracts Service a lot for helping me figure all this out. They didn't have to field my confused questions ("Hi. I'm trying to find the longest word in English, and I'm not sure what it is..."), but they did.

Incidentally, on top of being the first virus discovered, the tobacco mosaic virus was the first to have its shape and structure a.n.a.lyzed in a rigorous way. Some of the best work in this area was done by Rosalind Franklin, the crystallography expert who generously but naively shared her data with Watson and Crick (see chapter 8 chapter 8). Oh, and the "a" in "tryptophan synthetase protein" traces back to Linus Pauling's work on how proteins know how to fold into the proper shape (see chapter 8 chapter 8 again). again).

"mercifully known as t.i.tin": A few very patient souls have posted the entire amino acid sequence of t.i.tin online. Here are the stats: It occupies forty-seven single-s.p.a.ced pages of a Microsoft Word doc.u.ment in Times New Roman 12-point font. It contains over 34,000 amino acids, and there are 43,781 occurrences of A few very patient souls have posted the entire amino acid sequence of t.i.tin online. Here are the stats: It occupies forty-seven single-s.p.a.ced pages of a Microsoft Word doc.u.ment in Times New Roman 12-point font. It contains over 34,000 amino acids, and there are 43,781 occurrences of l; l; 30,710 of 30,710 of y; y; 27,120 of 27,120 of yl; yl; and just 9,229 of and just 9,229 of e. e.

"almost a proof in itself ": From a PBS From a PBS Frontline Frontline piece called "Breast Implants on Trial": "The silicon content of living organisms decreases as the complexity of the organism rises. The ratio of silicon to carbon is 250:1 in the earth's crust, 15:1 in humus soil [soil with organic matter], 1:1 in plankton, 1:100 in ferns, and 1:5,000 in mammals." piece called "Breast Implants on Trial": "The silicon content of living organisms decreases as the complexity of the organism rises. The ratio of silicon to carbon is 250:1 in the earth's crust, 15:1 in humus soil [soil with organic matter], 1:1 in plankton, 1:100 in ferns, and 1:5,000 in mammals."

" 'Bardeen was the brains of this joint organism and Brattain was the hands' ": The quote about Bardeen and Brattain being a joint organism comes from the PBS doc.u.mentary The quote about Bardeen and Brattain being a joint organism comes from the PBS doc.u.mentary Transistorized! Transistorized!

"a 'genius sperm bank' ": Shockley's "genius sperm bank," based in California, was officially called the Repository for Germinal Choice. He's the only n.o.bel Prize winner to admit publicly that he donated, although the sperm bank's founder, Robert K. Graham, claimed a number of others did, too. Shockley's "genius sperm bank," based in California, was officially called the Repository for Germinal Choice. He's the only n.o.bel Prize winner to admit publicly that he donated, although the sperm bank's founder, Robert K. Graham, claimed a number of others did, too.

"n.o.bel Prize for his integrated circuit": For information on Kilby and the tyranny of numbers, see the wonderful book For information on Kilby and the tyranny of numbers, see the wonderful book The Chip: How Two Americans Invented the Microchip and Launched a Revolution The Chip: How Two Americans Invented the Microchip and Launched a Revolution by T. R. Reid. Oddly, a club DJ using the handle "Jack Kilby" released a CD in 2006 called by T. R. Reid. Oddly, a club DJ using the handle "Jack Kilby" released a CD in 2006 called Microchip EP, Microchip EP, with a picture of a very old Kilby on the cover. It features the songs "Neutronium," "Byte My Scarf," "Integrated Circuit," and "Transistor." with a picture of a very old Kilby on the cover. It features the songs "Neutronium," "Byte My Scarf," "Integrated Circuit," and "Transistor."

3. The Galapagos of the Periodic Table.

"the reality of atoms": It might seem incredible to us today that Mendeleev refused to believe in atoms, but this was a not uncommon view among chemists at the time. They refused to believe in anything they couldn't see with their own eyes, and they treated atoms as abstractions-a handy way of doing the accounting, maybe, but surely fict.i.tious. It might seem incredible to us today that Mendeleev refused to believe in atoms, but this was a not uncommon view among chemists at the time. They refused to believe in anything they couldn't see with their own eyes, and they treated atoms as abstractions-a handy way of doing the accounting, maybe, but surely fict.i.tious.

"at least in history's judgment?": The best description of the six scientists competing to form the first systematic arrangement of elements can be found in Eric Scerri's The best description of the six scientists competing to form the first systematic arrangement of elements can be found in Eric Scerri's The Periodic Table. The Periodic Table. Three other people are generally given credit for coinventing, or at least contributing to, the periodic system. Three other people are generally given credit for coinventing, or at least contributing to, the periodic system.

Alexandre-Emile Beguyer de Chancourtois, according to Scerri, discovered "the single most important step" in developing the periodic table-"that the properties of the elements are a periodic function of their atomic weights, a full seven years before Mendeleev arrived at the same conclusion." De Chancourtois, a geologist, drew his periodic system on a spiral cylinder, like the thread of a screw. The possibility of his getting credit for the table was dashed when a publisher couldn't figure out how to reproduce the crucial screw diagram showing all the elements. The publisher finally threw his hands up and printed the paper without it. Imagine trying to learn about the periodic table without being able to see it! Nonetheless, de Chancourtois's cause as founder of the periodic system was taken up by his fellow Frenchman Lecoq de Boisbaudran, perhaps partly to get Mendeleev's goat.

William Odling, an accomplished English chemist, seems to have been a victim of bad luck. He got many things right about the periodic table but is virtually forgotten today. Perhaps with his many other chemical and administrative interests, he simply got outworked by Mendeleev, who obsessed over the table. One thing Odling got wrong was the length of the periods of elements (the number of elements that have to appear before similar traits reappear). He a.s.sumed all the periods were of length eight, but that's true only at the top of the table. Because of d-sh.e.l.ls, rows three and four require a period of eighteen elements. Because of f-sh.e.l.ls, rows five and six require thirty-two.

Gustavus Hinrichs was the only American on the list of codiscoverers (although he was not native-born) and the only one described as both a crank and a maverick genius ahead of his time. He published over three thousand scientific articles in four languages and pioneered the study and cla.s.sification of elements with the light emissions that Bunsen discovered. He also played with numerology and developed a spiral-arm periodic table that placed many really tough elements in the correct groups. As Scerri sums him up, "The work of Hinrichs is so idiosyncratic and labyrinthine that a more complete study will be required before anyone can venture to p.r.o.nounce on its real value."

"Earl Grey 'eats' their utensils": If you're dying to see the gallium practical joke in action, you can see a spoon of gallium melting into nothing on YouTube. Oliver Sacks also talks about pulling pranks of this sort in If you're dying to see the gallium practical joke in action, you can see a spoon of gallium melting into nothing on YouTube. Oliver Sacks also talks about pulling pranks of this sort in Uncle Tungsten Uncle Tungsten, a memoir of his boyhood.

"Streets are named for minerals and elements": For some of the descriptions of the history and geology of Ytterby and for details about the town today, I consulted Jim Marshall, a chemist and historian at the University of North Texas, who was extremely generous with his time and help. He also sent me wonderful pictures. Jim is currently on a quest to revisit the spot where every element was first discovered, which is why he traveled to Ytterby (easy pickings). Good luck, Jim! For some of the descriptions of the history and geology of Ytterby and for details about the town today, I consulted Jim Marshall, a chemist and historian at the University of North Texas, who was extremely generous with his time and help. He also sent me wonderful pictures. Jim is currently on a quest to revisit the spot where every element was first discovered, which is why he traveled to Ytterby (easy pickings). Good luck, Jim!

4. Where Atoms Come From.

"proved by 1939": One man who helped figure out the fusion cycles in stars, Hans Bethe, won a $500 prize for doing so, which he used to bribe n.a.z.i officials and spring his mother and, oddly, her furniture from Germany. One man who helped figure out the fusion cycles in stars, Hans Bethe, won a $500 prize for doing so, which he used to bribe n.a.z.i officials and spring his mother and, oddly, her furniture from Germany.

" 'chemically peculiar stars' ": A fun factoid: Astronomers have identified a strange cla.s.s of stars that manufacture promethium through an unknown process. The most famous is called Przybylski's star. The truly odd thing is that unlike most fusion events deep inside stars, the promethium must be created on the star's surface. Otherwise, it's too radioactive and short-lived to survive the million-year crawl from the fusion-rich core of a star to its outer layers. A fun factoid: Astronomers have identified a strange cla.s.s of stars that manufacture promethium through an unknown process. The most famous is called Przybylski's star. The truly odd thing is that unlike most fusion events deep inside stars, the promethium must be created on the star's surface. Otherwise, it's too radioactive and short-lived to survive the million-year crawl from the fusion-rich core of a star to its outer layers.

"stars govern the fate of mankind": The two portentous Shakespeare quotes that opened the B The two portentous Shakespeare quotes that opened the B2FH paper were as follows:

It is the stars, / The stars above us, govern our conditions.

King Lear, act 4, scene 3 act 4, scene 3 The fault, dear Brutus, is not in our stars, / But in ourselves.

Julius Caesar, act 1, scene 2 act 1, scene 2 "post-ferric fusion": To be technical, stars don't form iron directly. They first form nickel, element twenty-eight, by fusing two atoms of silicon, element fourteen, together. This nickel is unstable, however, and the vast majority of it decays to iron within a few months. To be technical, stars don't form iron directly. They first form nickel, element twenty-eight, by fusing two atoms of silicon, element fourteen, together. This nickel is unstable, however, and the vast majority of it decays to iron within a few months.

"low-watt, brownish light": Jupiter could ignite fusion with deuterium-"heavy" hydrogen with one proton and one neutron-if it had thirteen times its current ma.s.s. Given the rarity of deuterium (1 out of every 6,500 hydrogen molecules), it would be a pretty weak star, but it would still count. To ignite regular hydrogen fusion, Jupiter would need seventy-five times its current ma.s.s. Jupiter could ignite fusion with deuterium-"heavy" hydrogen with one proton and one neutron-if it had thirteen times its current ma.s.s. Given the rarity of deuterium (1 out of every 6,500 hydrogen molecules), it would be a pretty weak star, but it would still count. To ignite regular hydrogen fusion, Jupiter would need seventy-five times its current ma.s.s.

"like microscopic cubes": And not to be outdone by Jupiter's or Mercury's strange weather, Mars sometimes experiences hydrogen peroxide "snow." And not to be outdone by Jupiter's or Mercury's strange weather, Mars sometimes experiences hydrogen peroxide "snow."