Cementing the Future

Last autumn a 38-year-old retaining wall on my property was not looking fit for winter. Cracks had opened and the parge coat was peeling away.  Repeated freezing of moisture in the cracks surely would lead to more damage. With a bucket of cement and a trowel I hoped to stave off trouble. So far so good: even after the winter we just had, an inspection today shows the wall to be intact.

Cement and its grittier brother concrete (cement plus aggregate – usually stones though it can be other stuff such as fiberglass fibers) are marvelous materials. It is hard to find contemporary structures beyond the most rustic that don’t rely on them – at least for footings and foundations. Multistory commercial buildings are now more often framed with reinforced concrete than with steel. You can pour concrete into any shape, it won’t catch fire, and, while not indestructible, it is pretty hard to damage.

My first significant hands-on experience working with concrete was during my high school years. It was a summer job on a construction site. A basic grunt laborer, I wheeled barrows of it to sections of basement floors that the concrete truck’s chute wouldn’t reach and then rough-leveled it with rakes; the masons smoothed everything afterward. Outside, I did the same on patios after first hacksawing and setting rebar (steel reinforcing rods). Doing that for 8 hours a day doesn’t qualify as fun, but it did give me a better appreciation for the stuff.

Modern concrete dates only to the 18^th century. Making it is not an obvious process. The primary ingredients for cement are limestone (calcium carbonate) and silicate rocks, but, if all you do is crush them to powder and blend them with water, all you will get is mud. When the mud dries it will be powder again. To turn the mixed powder into cement you have to change it at the molecular level; to do this you heat it to an intense 1450 degrees C at which point the powders reform into calcium silicate. Now you’ve got cement. When you mix this with water and gravel you have concrete. Concrete doesn’t harden by drying in the usual sense; water is an ingredient that becomes part of the molecular structure of the hardening material. Internal water molecules continue to form new bonds long after the material feels dry to the touch, so concrete toughens as it cures, often for years.

The process for making Portland cement (so-called for its similar appearance to Portland stone) probably would have been discovered later than the 18^th century had not the folks of that era already known that it was possible. They knew because the ancient Romans had used concrete on a grand scale to build bridges, aqueducts, and buildings, many of which still stood. The Pantheon in Rome (completed 128 AD and still standing) to this day has the largest unreinforced concrete dome ever built. Roman techniques were forgotten in the years after the empire fell, but there obviously was some trick to them that only needed to be uncovered.

So how did the Romans figure it out in the first place? They cheated. More fairly, they got lucky. By geological happenstance, volcanic activity near what would become Naples was amid layers of limestone alternating with ordinary silicates. Superheated volcanic ash from this material formed a natural cement powder that accumulated over millions of years. The Romans needed only to dig it out of the ground. The mix wasn’t identical to modern Portland cement, but it was close enough to work. The Romans improved on the natural mix by adding lime: a single step which they worked out pretty early.

The problem with concrete, as with natural stone, is that it is amazingly strong in compression but very weak in tension. If you support a concrete horizontal beam at each end over an open space, the beam is under compression along the top but under tension along the bottom; so, it is likely to crack at the bottom. The crack will travel to the top and the beam will fail. This is also true of stone, and it is why all pure masonry structures need either arches or a lot of pillars; stone and concrete horizontal beams can’t span large spaces. This problem was solved in the 19^th century by Parisian gardener Joseph Monier. He wasn’t interested in construction. He just wanted flower pots that wouldn’t break as easily as ordinary clay or concrete pots. So, he embedded steel cages in flower pot molds and poured concrete into them. The technique worked perfectly, and the larger applications were immediately obvious. Steel excels in resisting tension, so a concrete horizontal beam reinforced with embedded steel rods can span long distances just fine.

There is very little that can’t be made out of concrete, but there probably are some things that shouldn’t be. More than a century ago, Thomas Edison, saddened by recent fatal fires in the news, decided that the answer was fireproof concrete homes filled with fireproof concrete furniture. He built his own cement plant in Stewartsville, NJ and built some demonstration poured-concrete houses (they still exist). He then produced concrete beds, concrete chairs, concrete sofas, concrete tables, concrete cupboards, concrete bureaus, concrete phonograph cases, and a concrete piano. They didn’t catch on. Go figure.

ZZ Top - Concrete and Steel

Pretty Prevarications

Last night I spun a DVD of Orson Welles’ F for Fake (1974), a look at deception that focusses on author Clifford Irving (of the Howard Hughes biography hoax) and Elmyr de Hory, the noted art forger. Orson of course achieved fame through a hoax of his own. Fans of Orson Welles will find it interesting, but I wouldn’t recommend it to a general audience. The film is leisurely and talky. Were it anyone but Orson talking it would be dull. Nonetheless it brought to mind some thoughts on deception.

An old adage says never to trust anyone who makes a point of telling you how honest he is. The risk is high that he is setting you up for a fleecing. At best he is demanding a free pass for rudeness, which is not the same thing as honesty. You know the fellow: just to be provocative, he says something completely out of bounds and then deflects criticism with the line, “Hey, I just say it like I see it.” The line itself is seldom true. The truth is often rude, but rudeness is not often the truth. The overlap is far from complete.

There clearly are situations in which we properly demand honesty. For good reason we outlaw fraud in financial transactions and perjury in the witness stand, but as everyday social lubricants lies are all but inescapable. After all, we all know (or should know) how to answer, “Does this make me look fat?”

From Bernard Shaw’s Arms and the Man:

BLUNTSCHLI. …You said you’d told only two lies in your whole life. Dear young lady: isn’t that rather a short allowance? I’m quite a straightforward man myself but it wouldn’t last me a whole morning.

RAINA (staring haughtily at him). Do you know, sir, that you are insulting me?

BLUNTSCHLI. I can’t help it. When you get into that noble attitude and speak in that thrilling voice, I admire you; but I find it impossible to believe a word you say.

Odds are, two lies wouldn’t last either Bluntschli or Raina ten minutes, never mind a morning. Nor would it be an adequate allowance for the rest of us. An article in the Journal of Basic and Applied Psychology describes an experiment in which roomfuls of people were allowed to interact socially without interference. Cameras unobtrusively recorded them. Each person then reviewed the tapes and was asked to identify the lies he or she told. The average was 2.92 lies every 10 minutes. Men and women lied about the same amount, but there was a difference in style, with men opting a bit more often for braggadocio and women lying more often for social convenience. No one was looking to defraud anybody in the usual sense of that term; they were just being social. 2.92 probably was an undercount since the researchers relied on participants to report honestly, and people notoriously posture even for social scientists; a few people (not very credibly) claimed not to have lied at all.

90 years before this experiment, HL Mencken understood the impulse perfectly. In The Art Eternal he wrote, “We ourselves are flawed and limited, and those of us not fortunate enough to be megalomaniacs are aware of it. Most of the time we feel outnumbered, outclassed, and (literally and figuratively) outgunned, and with good reason. It is not surprising that we are often are tempted to shorten the odds with dishonesty and to soothe ourselves with hypocrisy."

So, tell the truth on the stand, and don’t sell me an Elmyr by saying it is a Vermeer. But you look skinny in those jeans. Honestly.

Tell me sweet little lies

Five Films for a Snowy March

As winter continues to behave like winter in these parts (yet another snowfall is expected tonight), my home screen has seen some use. Five mini-reviews of flicks seen since March 1 follow.

CBGB (2013) – This movie was bound to get a tough reception from critics, many of whom had frequented the iconic club CBGB in NYC. Among the ones who didn’t nevertheless are many of an age to have grown up with the music of the bands and artists who broke out on its stage: The Ramones, Television, Patti Smith, Blondie, The Police, The Dead Kennedys, Talking Heads, and many many more. The music of our youth always attaches to us in a special way, even if we remain open to new sounds. How deft would a movie about this club have to be without it seeming to be a sacrilege to its demographic, and without evoking cries of, “No, that’s wrong!”? More deft than this one. The Village Voice, whose band reviews in the 1970s helped put CBGB on the map, ran a review of this movie titled “10 Things the CBGB Movie Got Wrong.”

All that duly acknowledged, the movie really isn’t as bad as all that. While flawed in more than 10 ways, it doesn’t deserve the wall of splats on Rotten Tomatoes. True, it does not provide any insight into the origins of punk and New Wave music, which reflected a collapse both of post-war “can-do” optimism and of ‘60s counterculture “flower power” naiveté. The movie does provide a sanitized, dramatized, but not entirely fabricated account of the accidental role that club owner Hilly Kristal (Alan Rickman) played in popularizing a new sound. Accidental it was: “CBGB” stands for “Country, Blue Grass, Blues,” which Hilly thought was the next big thing when he opened his dive in the Bowery in 1973. He was right, but it didn’t happen at his club; what happened there instead was something far more interesting.

CBGB is an inconsequential film with the feel of a made-for-TV-movie, but, if you’re not emotionally attached to the club itself (which closed in 2006) or to the scene it represented, you’ll likely find it amusing and perhaps even informative. Also, the music is good. On the other hand, if you personally stood in front of the stage in the 1970s (or the more hardcore 1980s), you’ll likely splat one of those tomatoes.

Thumbs sideways.

The Doors (1991) – Few movies set in the 1960s get the look, feel, and flavor of the decade right. The Doors is an exception. The film is pretty good beyond its general ambience, too. Lead singer Jim Morrison is played expertly by Val Kilmer and his fiancé Pamela Courson by Meg Ryan.

The iconic ‘60s rock band The Doors rises to fame after making a splash at the Whisky A Go Go in LA. Jim Morrison’s subversive appeal is the key to the band’s success, but he also poses the greatest risk to its existence. An all too familiar, but nonetheless well-told, tale of addiction and personal disintegration follows as Jim is unable to handle money and fame. Jim dies in Paris in 1971 at the age of (what else?) 27, apparently of a heroin overdose though this was never confirmed. Pamela died of an overdose in 1974 at age 27.

Thumbs up.

Birdman : or The Unexpected Virtue of Ignorance (2014) – This film received copious praise at the Academy Awards and elsewhere, and I’m not inclined to argue with it. Riggan Thompson (Michael Keaton) is an aging movie actor who gave up his starring role in a lucrative superhero franchise (Birdman) in order to direct and star in an artsy Broadway adaptation of a Raymond Carver short story. Commercial and artistic success for the play depends heavily on an erratic lead actor (Ed Norton). Riggan’s daughter Sam (Emma Stone) tells Riggan the play is a pretentious vanity production. Riggan’s alter ego Birdman tells him the same thing, much more persistently and rudely. Both have a point. Riggan might have telekinetic abilities that he hides from others. Or he might not: they might be a childlike fantasy to counter his self-esteem issues. In one scene (*mild spoiler*) he rises into the air, flies above city streets, and alights outside the theater; yet, a moment after he enters the theater, a cabbie runs in after him in order to collect his money. If that flight of fancy seems to answer the question of whether Riggan’s powers are all imaginary, it doesn’t. There are other reasons to wonder. Alejandro Iñárritu's direction of the film is unusual, with the bulk of it appearing (presumably through skillful cutting and splicing) to be a single shot.

Thumbs up.

John Wick (2014) – Are you looking for a movie as violent as Kick-Ass or Kill Bill but without the tongue-in-cheek humor? If the answer is no, don’t watch this. But if you find such fare cathartic, this action flick is about as well done as any. The anti-hero is John Wick (Keanu Reeves), a retired hit man for the mob whose wife has just died of natural causes. Unaware of Wick’s former connection to his dad, the chief mobster’s son along with some buddies breaks into his house, steals his car, and kills his dog, a present from his departed wife. So naturally, Wick has to kill everyone involved. It’s only right. It was his dog, man. Since the mobster tries to protect his son, this means taking on the entire mob, plus all the freelance killers out to collect the $2,000,000 bounty placed on Wick’s head. No problem. This is John Wick we’re talking about.

Thumbs sideways. Clarification: the film is fine by the standards of the action genre, but it takes itself too seriously for my personal taste. Also, Hollywood scriptwriters, stop making mob bosses Russian so often. It’s unimaginative and rude.

Forever Lulu (2000) – This film also can be found under the alternate title Along for the Ride. I’ve heard Melanie Griffith’s name mentioned at least a dozen times in the past couple of weeks, each time with the description “Dakota Johnson’s mom” appended. Fame truly is fleeting. One of Melanie’s better performances, however, can be found in Forever Lulu, which came from her own production company.

Lulu (Melanie) is a schizophrenic living in a halfway house. 16 years earlier she and Ben (Patrick Swayze) had a hot and heavy love affair that fell apart just as her mental health issues were intensifying. Unknown to Ben, she was pregnant when they broke up; she gave up the baby for adoption but made a deal with the parents to meet the boy when he turns 16. Ben is now a semi-successful writer married to a psychiatrist Claire (Penelope Ann Miller); he and Claire recently lost their son and are having marital problems. Lulu, on unauthorized leave from the halfway house, turns up and tells Ben about the kid. They go on a road trip to meet him. This disconcerts Claire who understandably does not have a professional detachment about the situation.

The movie received mixed reviews, with the film’s sentimentality making some reviewers uncomfortable. I’m not opposed to sentiment if it isn’t merely maudlin, and it isn’t here. Parts of this movie indeed are uncomfortable, but that is because the script and actors are credible.

Not for everyone, but thumbs up.

Behind the Eight Ball

When I was a kid, my mom was a fan of educational toys. She never described them as such, and so I didn’t think of them that way until years later. Even the comic books she brought home were likely to be Classic Illustrated, a brand that adapted famous novels. Thumbing her nose at Dr. Wertham’s anti-comic book crusade, she thought reading was reading and that if comics inspired it they were a good thing. Her plan worked. The first full-length adult novel I ever read was The Lost World by Arthur Conan Doyle; I opened it after having been inspired by the Classics Illustrated version. (That very 1959 edition hardback copy of The Lost World is still on my shelf.) She had less success with the art supplies and with science kits such as a chemistry set and a microscope. I played with them to be sure – dabbing paint, examining droplets of pond water, mixing powders in potentially dangerous combinations, and so on – but didn’t develop into an eccentric artist or a mad scientist. Too bad. Either persona might have worked for me, but at grammar school age I didn’t know.

Amazon’s website brought all this to mind a short time ago by listing chemistry sets under “Recommended for you.” My only explanation for this is the batch of oddball presents I buy for the Saturnalia event at my house in December. Somehow from these purchases Amazon’s algorithm decided “you might also like” a kids’ chemistry set. Well, maybe I would like one of those. But, I do notice from the description how much is not included compared to what was in my antique set. In that less safety conscious (or perhaps more parent-trusting) era, the bottled samples in my kit, if used properly, could have wreaked a modest degree of havoc. With the new kits one scarcely can blow up anything.

Of course, the manufacturers at the time were not completely reckless. My old set omitted most of the elements even then. This irked me as a kid because the set came with a periodic table that identified the 92 naturally occurring elements, and yet provided samples only of about two dozen – plus a few compounds useful for simple experiments. I figured the set should come with a majority of the elements anyway. I understood reasons for leaving off some: arsenic and thallium for two, which are too easily applied to the removal of inconvenient people. I grudgingly understood the omission of radium which I knew was radioactive, though I wasn’t aware how insanely expensive it is also. I also figured there was probably good reason to leave out uranium, given its utility in bomb making.

As it happens I was wrong about the uranium. It was then and is now perfectly legal for a private individual to own up to 15 pounds (7kg) of natural uranium. There are companies out there that will sell it to you, though don’t be surprised if some federal agency makes a note of it. You might already own some since one of the more mundane uses of the material is to glaze ceramics. Fiestaware dinnerware made before 1942 has uranium glazing; the plates turn up frequently on eBay. A large proportion of false teeth made before 1980 also flash uranium glazes. Radiation is not a cause for concern in either case – you’ll get more exposure from your granite kitchen countertops. Natural uranium is pretty safe because it contains only 0.71% U235, which is the usefully unstable isotope that powers fuel rods (enriched to 3% U235) or bombs (at more than 90% pure U235). More than 99% of natural uranium is tame U238, which has a half-life of four and one half billion years and therefore emits negligible radiation. If you want to be extra-safe you could opt for depleted uranium, which is uranium with U235 removed, though it is harder to come by since it is in high demand. The stuff makes great armor-piercing ammunition thanks to its density and its tendency to catch fire when it hits the target. Nonetheless, it probably is just as well I didn’t play with uranium as a kid. It was probably just as well I didn’t have the other 67 missing elements at my fingertips, either. I otherwise might have pursued a career as a chemist, and that can have a downside: I saw the last episode of Breaking Bad.

Those childhood kits, sets, and (alas) comics are long gone. A rummage through the attic, closets, and basement convinces me the microscope has vanished somewhere, too, though now I'm tempted to buy another one. In one dusty corner I did find one of those Magic 8-Balls, which still are manufactured as they have been since 1950; the ball will give one of 20 random answers when you ask it a question. I suppose using this device doesn’t quite count as science though.

Bush: The Chemicals Between Us

Weighty Matters

This morning an evil thing caught my attention: the bathroom scale. “Step on me!” it cried out soundlessly. I defied its siren call, but am likely to succumb at some point.

Inevitably (a wonderful adverb that extinguishes responsibility), I add pounds beginning Thanksgiving week and peak on or shortly after January 1. Rarely do those pounds begin to come back off before March. In modern fashion, I blame others for this, particularly greedy furniture manufacturers for making sofas so soft and comfortable that I sit on them too much instead of exercising to wear off excess calories. The sofas don’t even come with warning labels, except for the mysterious little tags that say, “This tag may not be removed under penalty of law.” Perhaps businesses should be forced to offer furniture made out of “healthy alternatives” such as concrete.  (Thomas Edison actually manufactured concrete furnishings in 1911 – they didn’t catch on.) Perhaps also there should be a hefty sin tax on soft cushions to discourage consumers from buying them. Or then again, I could stand up and walk around of my own accord, though that’s asking an awful lot.

Another option to lower my weight is to raise my elevation, though even at 10,000 feet above sea level weight is reduced only by about 0.1%. In order to drop a full pound I’d have to rise much too high to breathe. Besides, that is just weight. The real issue is mass: a balance scale will read the same at .1g as at 1g since both weights will have been reduced by the same amount.

The real solution is to buy a metric scale. This won’t change mass either, but at 2.2 pounds per kilogram, the number in the faceplate will be substantially lower, and that at least will be satisfying. Besides, a kg scale would be official. The US Congress formally adopted the metric system in 1866. Yes, it did. Not that it has made a difference. Not even the federal government makes much use of it even in minor matters. The 1970s stab at converting highway signs to kilometers, for example, was so unpopular the feds gave up on it after only a few years. Americans have some sense of weights though, thanks to their vices. P. J. O'Rourke: “Drugs have taught an entire generation of Americans the metric system.”

A couple of blogs ago I mentioned the redefinition of the second back in the 1960s. It was part of a general move toward defining measurements in fundamental and immutable terms. Scientists ran into trouble, though, while trying to redefine the kilogram as something other than the cylinder of 90% platinum and 10% iridium sitting in a case in Sèvres. (This chunk of metal itself was an 1889 redefinition of the previous “1000 cc of water” adopted by the French National Convention in 1795, a standard which had problems of its own.) The scientists’ problem in the 1960s was that redefinitions put on the table for the kg either were tautological or still effectively required weighing a physical object, so what was the point? Yet, the mass of the IPK (International Prototype Kilogram) cylinder isn’t constant. No matter how well it is protected, some contamination to the surface is inescapable. According to Livescience, the IPK “has gained tens of micrograms of mass” since it was cast. Since the IPK by definition is the kilogram, and since carefully made copies will contaminate at different rates in different environments, undesirable inconsistencies are introduced into very precise measurements.

Relief is on the way. In 2015 the kilogram is the last remaining SI (Le Système International d'Unités) measurement defined by a particular physical object, but a proposal exists for redefining it in terms of the Planck constant. In 2010 the International Committee for Weights and Measures put this on the agenda for 2014 but then delayed it to 2015. If this new definition is accepted, the problem will be resolved, though the technical challenges of measuring mass this way mean that all but a handful of people still will opt for a balance scale and metal weights.

If the new kilogram is large enough (perhaps we can include those contaminants), I can lower the readout on the bathroom scale a bit. That beats the alternative of eating less and exercising more. Anything but that.

Beatles – Carry That Weight

 

Of Lilts and Lesley

Earlier this month I stopped at the Green Knoll Grill. A friend was playing bass that night for Little Jimmy and the Starlites, a very good local band specializing in classic 50s-70s rock. There was a sizable crowd for the venue and a fairly enthusiastic one too, though naturally it was mostly older – not exclusively by any means, but mostly. I’m fully aware I fit the demographic, but it still looks funny to me to see gray-haired folks rocking out on the dance floor.

Even though I hadn’t heard many of the songs on the play list in years – in decades for a few – there were none to which I didn’t know the lyrics. The popular songs of our youth become entrenched in our psyches without any conscious attempt on our part to install them there. They not only provide a soundtrack to our lives but influence our perspective in ways of which we scarcely are aware until one evokes a strong emotion in us, often to the puzzlement of our older and younger companions. Music we encounter later in life can leave its mark too, especially if it is associated with some significant event or phase in our lives, but it never embeds itself in quite the same way as what entered our ears between the ages of 10 and 25. You can tell a lot about the quirks of a generation by listening to its music.

It should come as no surprise that we often feel an attachment (however one-sided) to the musicians/songsters as well as the songs. Back in January 2014 when Phil Everly died I commented about popular songs, “They are so interconnected with our life histories that when the artists who performed them die, we often feel the loss as a personal one.” All too frequently this happens when the performers are young (27 is a notoriously difficult age to survive), but in a way it is more unsettling when they begin to fall away at more natural ages: in the past year the departed include Joe Cocker (70), Paul Revere (76), Tommy Ramone (65), Johnny Winter (70), among others. Yes, I know the commonplace response is to say, “nowadays that’s young,” but in truth it isn’t. The deaths might well have been “too soon” by the way we like to reckon things, but the people were not really young. Neither are those of us whom they influenced, as we can’t help but be aware.

The latest to leave us is Lesley Gore (68) who began to chart when I was 10 (she was just 17) and who was a regular presence on radios and record players for the next decade. I’ll leave the commentary about her music and her life to others: there is quite a lot of that for a variety of reasons (many of them only tangentially related to her pop lyrics and sound), and there is little I can or wish to add. However, on a personal level, several of her songs are definitely entrenched in my mind in the way described above, and I’m glad they are. While news of her passing reminds me of my age, hearing her songs definitely makes me feel young.  Thanks for that, Lesley.

Lesley infatuated Robin when she was Catwoman’s sidekick in the “That Darn Catwoman” episode of Batman

Cesium the Moment

“Just a second,” said the young lady at the counter as she answered the phone.

She didn’t really mean my wait would be a second, of course. She meant it would be some indeterminate length of time that was short on a human scale. A second generally is too brief for humans to accomplish very much. However, it is long enough for a pygmy shrew’s heart to beat 14 times. A hummingbird can flap its wings 50 times per second while a bee averages 200. A photon will travel 299,792 km. Even for a human, it’s enough time to drive 88 feet in car going 60mph. I’m not hummingbird or a photon and I wasn’t in a car, so in the first second of waiting I didn’t flap my arms even once or travel anywhere that the entire earth wasn’t going anyway. Nor did I accomplish much in the next 50 or so seconds before she hung up the phone and turned her attention to my purchase. But it was enough time for my thoughts to wander to the matter of seconds, which I recalled were redefined sometime during my school years; a reference check once I was back home confirmed that they were.

The Sumerians came up with the traditional second (reflecting their peculiar sexagesimal predilection) even though they had no timepieces accurate enough to measure one. By definition an hour was 1/24 of a day; there were 3,600 seconds in an hour and 86,400 seconds in a day. This worked well enough for millennia, but by the 20^th century it posed a problem for scientists. The problem was that the earth’s rotation is variable, meaning the length of a second was variable too. This really wouldn’t do, so in 1967 a second was redefined as the time that elapses during 9,192,631,770 cycles of the radiation produced by the transition between two levels of the cesium 133 atom. An atomic clock that counts these cycles – using microwaves, resonance, and a crystal oscillator in a manner I don’t pretend to understand very well – is so accurate that it will drift no more than a second in 60,000,000 years, the length of time since the dinosaurs died. The first cesium clock was built in 1952, and so was well established technology by ’67.

The redefinition caused its own problems. That particular number of cycles was chosen because it matched the average second based on the earth’s rotation over the previous century. However, a slight slowing of the earth’s rotation caused by rising sea levels since the late 19^th century meant that by 1972 International Atomic Time already was off by a couple seconds from the common clock based on the earth’s rotation. In other words, by 1972 midnight came a couple seconds late. This wouldn’t do either, so in 1972 the leap second was introduced to re-synch the solar day while keeping the new definition of a second for all purposes. Whenever Universal Time (the common clock based on the earth’s rotation) drifts more than .9 seconds from International Atomic Time (which takes no account of earth’s rotation or its orbit) a “leap second” is added to the year, usually at midnight either on June 30 or on December 31. There have been 25 of these extra seconds since 1972. The last was in 2012, but we’ll have another in 2015 when June 30 will have 86,401 seconds.

The question “why cesium?” naturally came to mind. For once there was a fairly simple answer: the electron configuration of a cesium atom (a single electron in the outermost shell) makes it easy to manipulate for the purpose, and it has a higher cycle rate than other similarly suitable atoms such as rubidium. [Don’t get me started on “why cesium rather than caesium”; as a hangover from schoolboy Latin, my preference is the latter spelling but on these shores one gets corrected for using it; my Word 2013 has just underlined it in red.]

I also see that cesium has other interesting properties. For one thing it is yellow. This might seem a minor feature, but nearly all metals are grey or silver in color. The exceptions, notably gold and copper, tend to be valued for jewelry. So, why are there no cesium earrings, rings, and bracelets? For one thing it has a melting point of 28 degrees C (82 F), so the jewelry would turn to liquid at body temperature. This doesn’t really matter though, because it wouldn’t last long enough to melt. It would explode on contact with skin – more precisely on contact with the moisture of the skin – which would make short work of both the jewelry and the wearer. So, don’t give your sweetie a cesium necklace for Valentine’s Day this Saturday unless you are planning on ending the relationship.

Cesium and water