On a Briny Beach: An Introduction to Matter

The time has come,’ the Walrus said,
To talk of many things:
Of shoes — and ships — and sealing-wax —
Of cabbages — and kings —
And why the sea is boiling hot —
And whether pigs have wings.’

-Lewis Carrol, from Through the Looking Glass, 1871.

If you are left on a briny beach alone long enough you might get around to doing a dangerous thing, which is to say you might start to think. Now there are a lot of things to think about: politics, taxes, your family, your job, and all of these things are worth thinking about. But after you’ve stopped thinking about those things, all you will be left with is the scenery. When you look out at the sea stretching out before you, slowly eating at the shore, or smell the salt in the air, or feel the sand shift beneath your feet, you might ask what separates these things from each other. If you are feeling particularly dangerous, you might ask what separates you from these things.

Science is not independent of human desires, thoughts, hopes, or dreams, whether those desires and dreams be noble or perverse. We tend to talk about science like it is merely a method, but our relationship with science is in practice, more complicated. Science is a study, a verb, a history, a philosophy, a method, and a culture all rolled into a diffuse but powerful entity. And there is no better specialty and no better lens for seeing this than chemistry.

When I was a child, my family moved from Charlotte, North Carolina to Abu Dhabi, United Arab Emirates. Even for a boy whose father was Arab, it was a radical shift in lifestyle and culture. Common American brands became unfamiliar as British versions took their place under slightly different names, electric stoves were replaced by the ever-ominous gas cookers that could blow your house up (or so my mother constantly warned), and pseudo-suburban apartment complexes gave way to decidedly urban apartment buildings. But what I missed most at the time were the shows I’d gotten used to watching on television. Luckily, the UAE has a large Indian expatriate community, and our apartment’s default satellite package catered to them. My brother and I would watch the Indian channels because, despite being mostly in Hindi, they often had the syndicated American sitcoms and English language programming that we were hungry for as recent arrivals seeking the familiar.

On these channels there was a commercial in Hindi that my brother and I would see sometimes for a beauty product called “Fair & Lovely.” Since we were well and truly made of snips and snails and puppy dog tails, ads for cosmetics were mostly all the same to our eyes, but this one stood out. While most beauty product commercials showed you how their product would make your eyelashes longer, or your hair shinier, or your skin smoother, this one was unfathomable because we didn’t notice any difference between the “before” and “after” pictures. We thought that the “after” picture was maybe little lighter, like the brightness had been turned up, but we couldn’t figure out what the product was for. Finally we asked our mother what was going on. She explained that it was a skin bleaching cream, designed to make a person’s skin lighter. My brother and I were nonplussed. Our family was mixed Arab and Hispanic, and varied in color. We didn’t understand why your color was something was something you might want to change. Being young and naïve about concepts like colorism, much less how it was construed in communities outside our own, we shrugged and moved on with life.

You can still buy skin bleaching creams. Different types are being banned in some African nations due to health concerns, many products contain toxic mercury compounds, but Fair and Lovely is unlikely to fall under such a ban because it is not, in fact, a bleaching cream. The main ingredient appears to be nicotinamide, a variant of a common B vitamin, which can act locally, if weakly, as a melanin suppressor. So the term “bleaching” is not what it seems at first blush: Rather than a chemical term, it is more of a political term conjuring images of caustic chlorine and colorist attempts to erase an aspect of someone’s physical identity.

But if you look at Fair and Lovely’s packaging, there is something else going on there. The package has a floating motif that is, of all things, a double helix. It’s even a right handed helix, which is something that graphic designers tend to get wrong in images of DNA. It doesn’t explicitly claim to have anything to do with DNA, and of course it can’t, since it’s essentially a vitamin cream. So why include that in the image? Why place a model’s face inside the helix? Is she the same person in the background? What precisely are they selling?


Sure, I can look at the bottle, and I can read the ingredients, and I can understand what effects these substances have on the body. But after doing this, I still haven’t answered the question of what is being sold, only the question of what is in the bottle. The reality is that what is being sold is a vision of the product that appeals to the buyer’s personal understanding of chemistry and biology. To a lot of people, a DNA helix is a symbol in their mind. To them, it’s not a nucleic acid or set of structures with unique chemistry, it may not even be something they would call a “chemical.” For most people, it is a shorthand for identity, and for the self. Yet its chemistry is superficial, cosmetic; both literally and figuratively cheap. The packaging is heralding a momentous transformation of identity. In so many ways, the chemistry bought is not the chemical promise sold.

The point of the story is not to simply say that people are naïve about things, or about science, but instead that the people buying the product are astute to the symbols of the culture around them, and to the social signals that culture is sending them. Their chemical intuition is entwined with their culture, as is yours, as is mine. Even chemists are not completely immune to this effect.

The goal of this blog is to show that even without active thought, you probably respond to a chemical intuition that you absorb through culture. This blog will examine the interactions between that intuition and the science and study of chemistry. The goal is to break through some of the conditioning you’ve received about things as simple as soap and water, which you may have never really thought about. For example, yes, they clean things, but what does “clean” really mean? To see how the world comes together, we ask the questions beneath the questions, and give meaning to the phenomena.

So when you find that you are done sitting on that beach, and you finally slap the sand off of your clothes and body and move back into normal life as you know it, you might find yourself seeing things a little differently. Yes chemistry is important when it comes to offering solutions and answering questions about technology, war, sports, famine, health, and more. But it does so much more than that. Chemistry is unique among the physical sciences because our chemical understandings, intuitions, and aspirations are a mirror we can hold up to society. While biology tells us what we are, and physics tell us where we are going and how fast we are getting there, chemistry tells us not only who we are, but who we think we are.


Chemistry Pic of the Week: King’s Water



A little bit of a spin on the concept of “picture” this week. Instead, it’s a GIF of a freshly prepared batch of aqua regia. We were using it to remove any and all traces of metal from this piece of glassware so we could use it for a sensitive reaction later that day. Aqua regia means king’s water and it is so named because it will easily react with and dissolve what have historically been called “noble metals” like gold.

Aqua regia is incredibly dangerous and corrosive. The gases that come out of solution are also toxic and corrosive. It may be hard to see this, but the bars in the back of this fume hood have been corroded. All we do in this fume hood is make aqua regia and clean glassware. It’s not supposed to ever be removed from the hood, and because it generates gas, it cannot be kept inside of a closed container. Instead we make it in small quantities as needed, and work carefully inside of a fume hood. Minor technical note: There are some compression artifacts that make it look like there are particles on the finger of the person holding it, this is just how the GIF turned out after I made it small enough that it would load easily.

If you want some idea of why we use it to clean glassware, this flask had black iron staining that hadn’t come off after several days in a bath of hydrochloric acid. They disappeared almost instantaneously when we added the aqua regia. This picture was taken a moment after the flask was filled. There is a fascinating story that I’m researching at the moment about aqua regia that will have to wait for another post, so stay tuned for that, some time before the month is out!


Chemistry Pic of the Week: On Point

“I am ready and the words are beginning to well up and come crawling down my pencil and drip on the paper. And I am filled with excitement as though this were a real birth.”

-John Steinbeck, in a letter to his editor, Pascal Covici.

pencils2 - Copy.jpg

I’ve been away from the blog during the holidays and have returned with this picture of my desk. What you see is mostly some pretty standard writing pencils, a caseless pencil for drawing, and a carpenter’s pencil, which I like for making thick lines on the roll of butcher paper, which you can see I keep on my desk as a kind of moveable blotter. I sharpened up a bunch of pencils before I started working, as I tend to do, and got to thinking about them.

Pencils are, much like humans, most interesting for what’s inside of them, but their outsides are pretty interesting, too. There is a good chance that the pencil lying in a drawer nearby as you read this is made of incense cedar. If you’re not sure, pick it up, give it a quick sharpen, and smell it. It should smell coniferous, resinous, and vaguely like pine cones. To me, and perhaps to you, it might smell like the start of a project, second-grade pencil fights, and procrastinatory sharpening. In the increasingly dated 1998 rom-com You’ve Got Mail, Tom Hanks’s character writes to Meg Ryan’s character,

“Don’t you love New York in the fall? It makes me want to buy school supplies. I would send you a bouquet of newly sharpened pencils if I knew your name and address.”

To a chemist, smell is always interesting, because it represents one of one of the two most reliable senses we have available for direct chemical sampling and sensing. We are even trying to replicate it and improve it in various attempts at “electronic noses.” I recommend against it, but before the advent of reliable chemical tests and the concept of the atom, alchemists and early chemists tasted everything. The word “acid” comes from the Latin, acere, meaning “sour.” This hold true in other languages significant in alchemy and early chemistry, like Arabic, where the word hamdhiyat, meaning “sour things” still means acid to this day.  In cedars and pines, the smells we most vividly associate with them are with a class of compounds called terpenes.

If you’re linguistically astute, you might notice the similarity to the word “turpentine,” which is the distillation of pine resins. Terpenes are found abundantly in plants, and are responsible for all kinds of scents that we normally associate with them. The most obvious and famous terpene is probably pinene, that fresh pine scent that we put in everything from high-end perfumes to cheap car-deoderizers (which are of course, shaped like little pine trees). But the category includes limonene (in lemons) and humulene, which can be found in plants ranging from oranges, to hops, to various spices, and even tobacco and cannabis.

The reason incense cedar is picked for pencils is not its smell, however, but how easily the wood sharpens, and how easy the trees are to grow and farm. It’s the inside of the pencil, as I said earlier, that carries something far more interesting and potent: Graphite. The word itself is interesting, literally meaning “writing mineral” or “writing stone.” It was, initially called plumbago, because of its color, shine, and softness, it was thought to be a kind of lead ore, at first. The Latin word for lead, plumbum, explaining the chemical symbol Pb, and why people who fix water pipes are called plumbers–an artifact of the unfortunate tendency the Romans had to use lead for pipes and drinking vessels. It was also useful for writing, and making soft marks on surfaces, much like old lead styluses used since the Ancient Romans.

Soon enough, it was realized that this black rock that flaked onto surfaces had nothing to do with lead. Trying to untangle precisely when this happened and who did it turned out to be surprisingly difficult. Looking at old documents, it was confused with a lead ore known as galena for a long time, and it’s exact discovery is probably obscured to me both by the amount of time I want to spend researching this short post, and my inability to read German. In any case, it appears to have been Carl Wilhelm Scheele who discovered that graphite was not a form of lead, though it would be someone else to give it the name, “graphite.” Scheele’s life as a chemist was very interesting, and is worth picking up on in a later post.

Graphite itself is, of course, carbon, in layers of graphene. It’s this structure of sheets lying on top of each other that makes graphite what it is. Contrary to popular belief, graphite and diamond are not the same material. They are both different arrangements of carbon. While that may make them seem to be the same thing, let me remind you that the lyrics to your favorite song and the words in a toilet installation manual could technically be the same words, arranged differently. Graphene is one atom thick sheets of carbon, and while these sheets are very strong horizontally, they slip off of each other quite easily, making them suitable for drawing, and for lubrication. It’s this tendency for graphite to slip along the graphene planes like playing cards might slip over each other, that allows it to be deposited onto paper with simple friction. This same slipping tendency is also why it makes a good lubricant for situations where moving metal parts have to move against each other, and especially where in application where you might not want to use grease.

Graphite’s strong graphene sheets have made it useful for creating strong, lightweight composite materials, perfect for aeronautics. It found high tech uses not long after its discovery in England. Graphite was a military secret and asset in Elizabethan Britain, where it was used to lubricate the cannonballs that helped make the British Navy the military powerhouse that it was. But perhaps the most interesting secret use of graphite was in nuclear reactors.

Nuclear reactors have an undeserved reputation for being volatile. From the relative few nuclear incidents and accidents that have occurred and been documented, the general public has gotten the notion that nuclear reactors are one false step from catastrophe. The reality is, as any nuclear engineer will tell you, that they’re really most often one small incremental change from simply not producing any power. A nuclear chain reaction has to be carefully managed or it “fizzles” and stops happening. One of the ways that a nuclear reaction has to be managed is using something called a “moderator.” Moderators slow down neutrons so that they can more easily be captured by uranium atoms and those atoms can then fission producing more neutrons for the chain reaction. If the neutrons move too fast, they essentially whiz past the uranium atoms too fast for a nuclear reaction to happen. Graphite happens to be a great moderator, slowing neutrons down to the right speeds.

When the British started their own nuclear program post-World War II, they built a reactor at Windscale. The problem was that the Americans kept their cards close to the vest, and didn’t really want to share nuclear secrets with Britain, despite their alliances and the fact that numerous British scientists had worked on the Manhattan Project. The British knew graphite was an excellent moderator, but they did not know about an effect called “Wigner expansion” or “Wigner growth.” When neutrons bounced off of a carbon atom, they’d sometimes hit it hard enough to push it out of the crystal structure of the graphite. After a while, the graphite would start to expand due to this effect. If you knew about it, you could build for it. The British, initially, did not know about it, and they didn’t build for it.

There was no room for the graphite moderator to grow, and the graphite would form stresses and cracks. The scientists at the Windscale reactor would solve this problem with a process called annealing, which involved heating the graphite. Understaffed, in the middle of a flu epidemic, and engaged in a desperate nuclear arms race, the Windscale reactor was working furiously in October of 1957. The reactor fuel was metallic uranium, which is flammable in air, and was contained in metal tubes. They also had tube of flammable lithium and magnesium to produce tritium, an isotope of hydrogen necessary for hydrogen bombs. Flammable is actually an understatement. These materials were pyrophoric, meaning that they would burst into flame on contact with air. Air was used to cool the whole operation. To reiterate:


  • The staff was overworked.
  • The fuel was flammable.
  • The graphite was flammable.
  • The tritium precursors were flammable.
  • Both the precursors and the fuel would ignite on contact with air.
  • The reactor was air cooled, with industrial blowers pushing air through the piles.

In addition the controls were cumbersome and slow. In an era before computer microprocessors, much of the reactor control was manual. After an annealing cycle, temperatures began to rise uncontrollably in sections of the reactor, culminating in a full fledged and disastrous fire, which burned up radioactive materials and carried them in smoke. 200 square miles north of the reactor were contaminated, much of it dairy land. The official inquiry blamed the fire on the graphite annealing process. The reality, based on subsequent thinking, and espoused by nuclear engineers such as James Mahaffey, is that one of the canisters with flammable materials was very likely to have burst. It remains the worst nuclear accident in British history. One of the more interesting things about the Windscale fire was its location, only about 13 miles from the town of Seathwaite, in Cumbria, England. That’s where graphite was first discovered, and was used to mark sheep. Of course our atomic age mineral and then later, a space-age one, started life as a humble pencil.

Book Review: Swindled

Myths and beliefs about food and drink vary across cultures and time. Yet, there is something persistent about fears of food contamination. And those fears aren’t unwarranted, as laid out by Bee Wilson‘s excellent book, Swindled: The Dark History of Food Fraud, from Poisoned Candy to Counterfeit Coffee.

The book has an unfortunate tendency to denigrate the role and science of chemistry in a way that weakens some of its conclusions, but overall I recommend it as a breezy and informative read about food adulteration mainly in western Europe and the United States. The book raises a question central to most human societies: What does pure and wholesome food look like?

To answer this, Wilson raises the question of what an adulterant is, and when it becomes an ingredient as opposed to a trick played on the consumer. She narrows it down to two categories: poisoning and cheating. As straightforward as it seems, there are peripheries where the lines blur. After all, people pay good money for authentic fugu sashimi, a Japanese delicacy where the flesh of the pufferfish is carefully prepared and served, with at least some of the poisonous tetrodotoxin contributing to the overall experience. It’s indisputable that the epicurean in this case is being (slightly) poisoned, but at least they’re not being conned. Other times it seems that we ask to be convinced our food is more wholesome than it is, as is the case with products like “raw sugar” which is really just turbinado sugar, an old method of sugar preparation that retains some of the impurities, none of which cancel or appreciably reduce the number of calories or glycemic index of the sugar you’re consuming. Though some find the large crystal size and slight malty flavor appealing, the additional minerals aren’t particularly hard to come by in an American diet.  But what Wilson takes highest issue with, and rightly so, is when the person eating is being deceived, as in the tragic Chinese fake milk scandal in 2008.

She starts her investigation in Great Britain during the 1800s. Here, we find our first hero, Friedrich Accum, an accomplished German chemist who found himself on a mission to prove to the English that they didn’t eat very well, and that their food was often faked or poisonous. He wrote A Treatise on Adulterations of Food and Culinary Poisons in 1820. In it, he not only informed the public on how they might go about verifying whether they’d been cheated, but went so far as to name names, listing grocers and vendors who’d been prosecuted and convicted for providing impure ingredients. His story, however, doesn’t end happily. His credibility in Britain would be destroyed in an incident where he was caught tearing a page out of a library book, leading him to flee back to Germany. Note to self: Don’t mess with British librarians.


Frontispiece of Accum’s Book. (Public domain image obtained from the Wellcome Trust)

Despite the efforts of Accum and others, the state of food safety and preparation in urban areas in the 1800s was dismal. People had lost any sense of what food was supposed to look like or smell like. Even as people in the modern era deride “fake” food, we have access to recipes and photographs at the touch of a button, and powerful governments that at least theoretically care about setting minimum standards for food quality. Often what we call “fake” is really just mass-produced. When you buy the cheapest possible coffee in the store, labelled “100% coffee” at least you can be sure that you’re getting A) Ground up beans from B) A plant in the Coffea genus. It may be an inferior species, grown in substandard soil, but at least it’s coffee. People in 1800s Britain might be getting chicory instead, or toasted grains made up to look like coffee. But at least those substitutes wouldn’t kill you.

In one story, Accum found a woman who was surprised that the green tea she purchased turned deep blue when she added ammonia to it. She wasn’t trying to test for anything; at the time, ammonia was used medicinally, though no doctor would recommend it now. The liquid turned blue because people would fake tea by drying sloe leaves (an unrelated plant) and simulate the color of green tea by adding copper carbonate, which has a light green color. It is also extremely toxic. When the woman added ammonia, she inadvertently made a copper-ammonia-water ion complex pictured below, which is deep blue. She took her tea to Accum who precipitated the copper and showed it to her, though we never find out what happened to the vendor who sold the tea.


Ball-and-Stick Model of Tetraamminediaquacopper(II) cation. Public domain image by Ben Mills and Jynto.

Stories like this abound, but perhaps more interesting were the systemic issues that seemed to come up again and again in history. It always seemed that there was a tension between the bakers, grocers, and vintners and the state. These would give way to larger conflicts with industrialized food manufacturers. Especially in turn-of-the-century Britain and the United States, the argument seemed to be that the consumer should choose their poisoners, but after any number of high profile scandals, such as that caused by Upton Sinclair’s The Jungle in the United States, governments found they were increasingly pushed to regulate food quality standards more strictly.

Maybe the most interesting effort in getting the US government to regulate food safety came from Harvey Washington Wiley. Wiley, a Hoosier physician, would end up conducting a series of tests on the effects of new preservatives that were being used in food. Somewhat notoriously, he did this by using federal founds to found what would come to be known as the Poison Squad.

The Poison Squad was one of those unique oddities of its time that we can hardly imagine happening today. One part science and two parts publicity stunt, Wiley would assemble a team of young, healthy men and feed them preservatives in increasingly larger amounts and they would report any symptoms that they experienced. Preservatives are one of those issues that have largely faded from public consciousness and even fad labeling. This is largely because the legacy of truly harmful preservatives in food like formaldehyde has faded from memory. Originally called hygienic table studies, the media quickly came up with the much catchier and longer-lived name of “The Poison Squad.” This attention from the national press directly contributed to the 1906 Pure Food and Drug Act, which laid the groundwork for the modern Food and Drug Administration in the United States.

The hardest thing about reviewing this book is that the subject is so vast, that there is the temptation to wish it covered more and that it accomplished more. But when I examined her sources, I found that there was a great deal she didn’t include because she couldn’t possibly have the time. So I have to give her credit for being such a careful curator, keeping the book narrowly focused and not indulging too much in our desire for tales of despotic food inspectors, lowlife grocers, and irascible scientists. The style is straightforward, if opinionated at times, but her sketches of the various historical characters are so compelling that we can’t help but feel a thrill when a food adulterer is caught out, or anger when a government fails to act on of the many heroes’ discoveries of poison and chicanery in the local market stalls.

Perhaps one of the few failings of this book is a failure to learn from the highly artificial ways that humans divide the food world into “wholesome” and “unwholesome.” The ethnographer, Stephen Mintz observed in his book, Sweetness and Power that people have odd and highly arbitrary ideas of what makes food a meal, and noted that globally we will eat almost anything not acutely toxic. Yet Wilson, a food writer by profession, seems to reinforce some Platonic ideal of wholesomeness. She writes as part of her conclusion,

We would need to be taught what medieval eaters knew instinctively: what bread tastes like when it is made from nothing but flour, water, salt, and leavening; what ham tastes like when it hasn’t been injected with excess water; how Basmati rice smells and how it differs from long-grain rice. Children in schools should be taught how vegetables are grown–without pesticides– and how they can be cooked–without additives…

The problem is that even cheap supermarket Wonderbread is largely made of flour, water, salt, and leavening, with other ingredients added to preserve the loaf, and to enrich its vitamin content. I suppose I don’t see the con here. What’s the adulterant? Who is being swindled, and how? She talks about the cheap loaves of bread that bakers were once mandated to bake as food for the poor and this bread is no different: wholesome, and because it keeps well and can be mass-produced, cheap. She talks about the cheap loaves of bread that baker’s were mandated to once bake as food for the poor and this bread is no different in many ways. It keeps well and can be mass-produced cheaply, and gives nutrition to the people eating it. The ingredients are listed plainly. No one is going to suffer appreciably from eating it day after day, week after week, as part of a balanced diet. Blandness is regrettable, but not deceptive. And to her point above, about cooking with additives—how does one cook without additives?

Every spice and salt you add is an additive. Is brioche a lesser bread because it’s made with egg? Is a barbecued brisket malformed by the addition of the heady mix of compounds in smoke? If make my own liquid smoke on a grill with wood chips and a bundt pan and season my food with it, is it an additive? I doubt Wilson would say so, but I wonder what she would think of a burger chain adding liquid smoke to their griddle cooked burgers. Her contemplation of what constitutes an additive as opposed to be ingredient seems artificial.

Wilson is often arguing to engage a person’s innate sense of the world. She’s appealing to a sort chemical intuition we have about the world, rather than actual information. Take the passage,

There is another kind of deception going on too–a kind of collective self-deception. Fortification can disguise the fundamental inadequacies of the diet eaten by the general population. By bolstering the intake of certain select vitamins , fortification can give the impression that, in large industrial societies, the food of the poor or uneducated is not so much worse than the food of the rich or educated. This is an illusion. On grounds of both taste and nutrition , there is a great difference between eating a whole, tart, juicy orange, rich in fibre as well as natural flavour, and eating [sic] an orange-flavour drink fortified with vitamin C; or between eating a slice of real, malty wholegrain bread, naturally rich in B vitamins, and eating an industrially produced square of fortified white “bread.”

This statement is constructed in a way that’s hard to disagree with, except that the comparisons are false. Poorer consumers are not drinking orange flavored drink to replace oranges. Instead they are eating conventionally grown oranges as opposed to organic oranges (which are nutritionally identical), or they’re not eating a well-balanced diet for a variety of reasons and aren’t eating enough fruit to begin with. She raises the issue of widespread folic acid masking B12 deficiency, but she glosses over the complexities of what happens when public health initiatives have trade-offs. Meanwhile, nutritional deficiencies are not being “hidden,” but alleviated. CDC data [PDF] show a small minority of Americans with nutritional deficiencies, with some complex factors accounting for why those minorities exist.  For instance, vitamin D is often obtained from exposure to sunlight. People with darker skin need more sunlight to synthesize vitamin D, and much of the US receives less sunlight during the year than would be ideal for these groups, which means the vitamin D from diet becomes a more important factor than it otherwise would be.

As for bread, I do not dispute the difference in taste between Wonderbread and a fine loaf of ciabatta, or a yeasty samoon, or buttered Irish soda bread. But on nutrition grounds, I strongly doubt that there is a real difference between a home-baked whole grain bread and a square store-bought loaf. If instead of comparing oranges to orange drink we compare apples to apples and whole grain to whole grain, the differences have a tendency to disappear.

But since we are on the topic of bread, we need to discuss something that Wilson does which I call the “uncertainty sandwich.” I don’t want to spend much more time impugning a book that I think is good, and that I think you should read, but watch for this structure:

  • A statement that a particular food or additive may be bad for you.
  • An admission there is no scientific evidence it is bad for you.
  • A remark on why that evidence does not change her mind.

I don’t think Wilson is being dishonest with this, but I do think it’s worth noting that the actual scientific evidence is always couched this way when Wilson wants to make a point. You’ll notice it once you’re aware of it, and a particularly interesting example is in the discussion around aspartame.

I don’t think she ever answers the question of what a “pure” food looks like to my satisfaction, but I don’t think her suggestions are outlandish or unreasonable: that we all become more intimate and familiar with the preparation of our food and its production. As for my answer to the question, I think the question is wrong. I think that once you go beyond deception, and start to discuss ingredients in complex foods, the concept of pure food is nonsensical. Olive oil, coffee, flour, and sugar: These things can be pure. But once you start to build a cuisine, all bets are off.

Fermentation processes produce an almost mystical range of compounds that we don’t directly control, so there is nothing pure about cheese, or wine, or even bread. It’s not like every one of these fermentation compounds has been tested or proven safe, yet it is indisputable that the esters and carboxylates invented by the yeasts we use are just as much a flavoring as anything we might add to bread. But to the mind, a homemade loaf of bread is still “purer” and more “clean” than a supermarket English muffin, where every ingredient is known and controlled carefully. We are socially conditioned to feel certain ways about food, and that’s okay, but we don’t need to justify it with flawed reasoning and vague ideas of “purity.” The heart may want what the heart wants, but the stomach is in fact less discriminating.

Food isn’t polluted by being subjectively inferior to other food, it’s simply different. Human beings are historically remarkably diverse in what we call food and what we desire from it. Purity here, becomes more of a psychological term than a technological one, and I think that Wilson could have written an even more compelling end to an already compelling book if she could have seen her way to that fact.

Chemistry Pic of The Week: Light and Oil



And they sought after pure olive oil to light the lamps therewith, but could not find any, except one bowl that was sealed with the signet ring of the High Priest from the days of Samuel the prophet and they knew that it was pure.

The Scroll of Antiochus

I write this on the seventh night of Chanukkah. My girlfriend is Jewish and like many chemists, I’m a bit of a pyromaniac, so I manage to get excited about the lighting of candles. For those unfamiliar with the celebration, it’s a minor Jewish holiday that enjoys a high profile in North America due to its proximity to Christmas. What’s interesting to me is that this ancient celebration commemorates something we can relate to in the modern era.

The story goes than an ancient king of the Greek Selucid Empire outlawed Judaism and made sacrifices to Zeus in their Second Temple. A Jewish priest and his sons led a revolt against the Greek king and prevailed. After taking the temple back from the Greeks, they could only find one jar of kosher oil with which to light the menorah, a ceremonial lampstand in the temple. Here, we’re talking about oil lamps. The miracle commemorated was that the oil lasted for eight days instead of one, giving time to make more new oil.

That’s right, oil. But we’re not talking about petroleum from the ground or heating oil, which is derived from it. We’re talking about something you’ll likely find in any kitchen: Olive oil. While the ancient Jews used olive oil for ceremonial purposes, drippings from animal fat, and oils derived from other plants have been used by people all over the world for centuries to make light.

While the ancients in the story used olive oil, this rhymes with our current anxieties around fossil fuels. Petroleum literally means “rock oil” and one of the big fears around fossil fuels is that they will eventually run out, leaving us with nothing to light our ever expanding cities and towns. These fears have largely been overshadowed by our concerns about global warming, which are equally valid. Meanwhile, the discovery of new methods of oil extraction such as hydraulic fracturing, and the discovery of exploitable oil shale in the United States has significantly changed our estimate for when we lose access to cheap petroleum. The oil is lasting longer than expected. The question becomes whether we use this extension on cheap fossil energy to develop technologies that take us beyond them, or to grow complacent as we add ever more carbon to the atmosphere.

Chemistry Pic of the Week: Life in the Emerald City

In L. Frank Baum’s book, The Wonderful Wizard of Oz, when Dorothy and her friends finally reach the Emerald City to meet the Wizard of Oz, they’re given special sets of glasses, to protect their eyes from the brilliance of the city. Later it’s found out that the glasses are simply tinted green, and that the city isn’t actually all green to begin with, but it’s all part of an illusion crafted by the Wizard of Oz. But you may have noticed that even regular glass has a green tint to it, as long as you view it on the thicker edge.


What you might have learned in school is that glass is comprised of SiO2, or silica. But the reality is slightly more complicated. Glass is a complex mixture, and glaziers (that’s what you call someone who makes glass) have been tweaking the recipes for different types of glass long before we ever really understood the chemistry.

The image here is of some soda-lime glass, so called because of the presence of added sodium and calcium oxides (soda and lime, respectively.) These give the glass certain properties. The soda makes the glass very workable and meltable, which is important for the glass-maker. As for the lime… well, that deserves its own post, but the short of it is that if you add soda, the glass would dissolve in water if you don’t add lime as well. The green color comes from a third component you may be familiar with, and that’s iron, specifically iron (II) oxide or FeO. If you are close to the desert or the beach, try this:

Gather some sand and a really strong magnet. spread a thin layer of sand on the table and see if anything in the sand moves when you wave the magnet over it. You’ll notice, depending on the strength of your magnet, that some dark particles may be attracted to your magnet. These are bits of a mineral called magnetite. The amount of magnetite you can come by will vary depending on your local geology, and it’s a mixture of iron oxides. In addition to magnetite, there is also hematite, but that doesn’t respond to magnets.

So it comes as no surprise that iron ever made its way into glass. Historically, the first crude attempts at glass likely came from working with whatever sand was laying around, minerals and all. The glass can also acquire a yellowish tint if the dominant iron impurity is Fe2O3 or iron (III) oxide, which you may be more familiar with as red or brown rust. A greener tint means that the iron impurities in the glass absorb their opposite color (redder light), and a yellow tint implies that the glass absorbs bluer light. This is used by glass manufacturers to make glass melt faster, since they can use methods of infrared heating (redder light beyond what’s visible to the human eye) to heat glass with iron (II) oxide impurities faster, since they know the glass will absorb that wavelength of light, and therefore the energy of that light.

So why isn’t everything green when you look through a window? Actually it is. Most of the glasses you look through are just too thin for you to pick up on the subtle filtering of red light. You’ve lived in the Emerald City your whole life, you’ve just never realized it.

Watch a Climate Scientist Talk About How Science is Funded

Katherine Hayhoe, with PBS Digital Studios made this really cool video where she explains not only why scientists receive such large grants, but where it goes.

Grant money is not money for researchers, but money for research. While it may ultimately go to salaries, as is often the case when it comes to paying graduate students (they gotta eat, too), that doesn’t mean it’s a lot. In fact the relatively high cost of labor and facilities means that these sums often work out to be very little. Grants are necessary paperwork headaches and take time away from what scientists really want to do: Science.

Grants bring accountability. Grants from the federal government in particular can lead to financial audits, so researchers have to keep all their ducks in a row and account for every penny, just like you do come tax time, except that unlike your tax returns, federally funded projects are public. They can easily become politicized. Take for example, Climategate.

While it turned out to be a tempest in a teapot that was ultimately about taking hacked emails out of context, the National Science Foundation’s Office of the Inspector General conducted an investigation. That’s right, the NSF has an Inspector General, and it looks into scientific misconduct and whether federal funds are used appropriately. So when scientists hear someone say that scientists just say certain things to get more funding, there’s a very real disconnect to how funding actually works. What’s funny is that the organizations most likely to give unrestricted, unregulated money to scientists are industry groups of various kinds. Politically motivated environmental groups don’t necessarily like to direct their money to scientific funding, instead preferring to spend that money on lobbying and campaigning.

The next time you hear that global warming is made up by scientists who “are just after funding,” ask them how they think grants and scientific funding works and how easy they think the process is.