Carbon dioxide: the good, the bad, and the future

Carbon dioxide is a small molecule with the structure O=C=O

Carbon dioxide has been in and out of the news this summer for one reason or another, but why? Is this stuff helpful, or heinous?

It’s certainly a significant part of our history. Let’s take that history to its literal limits and start at the very beginning. To quote the great Terry Pratchett: “In the beginning, there was nothing, which exploded.”

(Probably.) This happened around 13.8 billion years ago. Afterwards, stuff flew around for a while (forgive me, cosmologists). Then, about 4.5 billion years ago, the Earth formed out of debris that had collected around our Sun. Temperatures on this early Earth were extremely hot, there was a lot of volcanic activity, and there might have been some liquid water. The atmosphere was mostly hydrogen and helium.

The early Earth was bashed about by other space stuff, and one big collision almost certainly resulted in the formation of the Moon. A lot of other debris vaporised on impact releasing gases, and substances trapped within the Earth started to escape from its crust. The result was Earth’s so-called second atmosphere.

An artist’s concept of the early Earth. Image credit: NASA. (Click image for more.)

This is where carbon dioxide enters stage left… er… stage under? Anyway, it was there, right at this early point, along with water vapor, nitrogen, and smaller amounts of other gases. (Note, no oxygen, that is, O2 – significant amounts of that didn’t turn up for another 1.7 billion years, or 2.8 billion years ago.) In fact, carbon dioxide wasn’t just there, it made up most of Earth’s atmosphere, probably not so different from Mars’s atmosphere today.

The point being that carbon dioxide is not a new phenomenon. It is, in fact, the very definition of an old phenomenon. It’s been around, well, pretty much forever. And so has the greenhouse effect. The early Earth was hot. Really hot. Possibly 200 oC or so, because these atmospheric gases trapped the Sun’s heat. Over time, lots and lots of time, the carbon dioxide levels reduced as it became trapped in carbonate rocks, dissolved in the oceans and was utilised by lifeforms for photosynthesis.

Fast-forward a few billion years to the beginning of the twentieth century and atmospheric carbon dioxide levels were about 300 ppm (0.03%), tiny compared to oxygen (about 20%) and nitrogen (about 78%).

Chemists and carbon dioxide

Flemish chemist Jan Baptist van Helmont carried out an experiment which eventually led to the discovery of carbon dioxide gas.

Let’s pause there for a moment and have a little look at some human endeavours. In about 1640 Flemish chemist Jan Baptist van Helmont discovered that if he burned charcoal in a closed vessel, the mass of the resulting ash was much less than that of the original charcoal. He had no way of knowing, then, that he had formed and collected carbon dioxide gas, but he speculated that some of the charcoal had been transmuted into spiritus sylvestris, or “wild spirit”.

In 1754 Scottish chemist Joseph Black noticed that heating calcium carbonate, aka limestone, produced a gas which was heavier than air and which could “not sustain fire or animal life”. He called it “fixed air”, and he’s often credited with carbon dioxide’s discovery, although arguably van Helmont got there first. Black was also the first person to come up with the “limewater test“, where carbon dioxide is bubbled through a solution of calcium hydroxide. He used the test to demonstrate that carbon dioxide was produced by respiration, an experiment still carried out in schools more than 250 years later to show that the air we breathe out contains more carbon dioxide than the air we breathe in.

In 1772 that most famous of English chemists, Joseph Priestley, experimented with dripping sulfuric acid (or vitriolic acid, as he knew it) on chalk to produce a gas which could be dissolved in water. Priestley is often credited with the invention of soda water as a result (more on this in a bit), although physician Dr William Brownrigg probably discovered carbonated water earlier – but he never published his work.

In the late 1700s carbon dioxide became more widely known as “carbonic acid gas”, as seen in this article dated 1853. In 1823 Humphry Davy and Michael Faraday manged to produce liquified carbon dioxide at high pressures. Adrien-Jean-Pierre Thilorier was the first to describe solid carbon dioxide, in 1835. The name carbon dioxide was first used around 1869, when the term “dioxide” came into use.

A diagram from “Impregnating Water with Fixed Air”, printed for J. Johnson, No. 72, in St. Pauls Church-Yard, 1772.

Back to Priestley for a moment. In the late 1800s, a glass of volcanic spring water was a common treatment for digestive problems and general ailments. But what if you didn’t happen to live near a volcanic spring? Joseph Black, you’ll remember, had established that CO2 was produced by living organisms, so it occurred to Priestly that perhaps he could hang a vessel of water over a fermentation vat at a brewery and collect the gas that way.

But it wasn’t very efficient. As Priestly himself said, “the surface of the fixed air is exposed to the common air, and is considerably mixed with it, [and] water will not imbibe so much of it by the process above described.”

It was then that he tried his experiment with vitriolic acid, which allowed for much greater control over the carbonation process. Priestly proposed that the resulting “water impregnated with fixed air” might have a number of medical applications. In particular, perhaps because the water had an acidic taste in a similar way that lemon-infused water does, he thought it might be an effective treatment for scurvy. Legend has it that he gave the method to Captain Cook for his second voyage to the Pacific for this reason. It wouldn’t have helped of course, but it does mean that Cook and his crew were some of the first people to produce carbonated water for the express purpose of drinking a fizzy drink.

Refreshing fizz

You will have noticed that, despite all his work, there is no fizzy drink brand named Priestly (at least, not that I know of).

Joseph Priestley is credited with developing the first method for making carbonated water.

But there is one called Schweppes. That’s because a German watchmaker named Johann Jacob Schweppe spotted Priestley’s paper and worked out a simpler, more efficient process, using sodium bicarbonate and tartaric acid. He went on to found the Schweppes Company in Geneva in 1783.

Today, carbonated drinks are made a little differently. You may have heard about carbon dioxide shortages this summer in the U.K. These arose because these days carbon dioxide is actually collected as a by-product of other processes. In fact, after several bits of quite simple chemistry that add up to a really elegant sequence.

From fertiliser to fizzy drinks

It all begins, or more accurately ends, with ammonia fertiliser. As any GCSE science student who’s been even half paying attention can tell you, ammonia is made by reacting hydrogen with nitrogen during the Haber process. Nitrogen is easy to get hold of – as I’ve already said it makes up nearly 80% of our atmosphere – but hydrogen has to be made from hydrocarbons. Usually natural gas, or methane.

This involves another well-known process, called steam reforming, in which steam is reacted with methane at high temperatures in the presence of a nickel catalyst. This produces carbon monoxide, a highly toxic gas. But no problem! React that carbon monoxide with more water in the presence of a slightly different catalyst and you get even more hydrogen. And some carbon dioxide.

Fear not, nothing is wasted here! The CO2 is captured and liquified for all sorts of food-related and industrial uses, not least of which is fizzy drinks. This works well for all concerned because steam reforming produces large amounts of pure carbon dioxide. If you’re going to add it to food and drinks after all, you wouldn’t want a product contaminated with other gases.

Carbon dioxide is a by-product of fertiliser manufacture.

We ended up with a problem this summer in the U.K. because ammonia production plants operate on a schedule which is linked to the planting season. Farmers don’t usually apply fertiliser in the summer – when they’re either harvesting or about to harvest crops – so many ammonia plants shut down for maintenance in April, May, and June. This naturally leads to reduction in the amount of available carbon dioxide, but it’s not normally a problem because the downtime is relatively short and enough is produced the rest of year to keep manufacturers supplied.

This year, though, natural-gas prices were higher, while the price of ammonia stayed roughly the same. This meant that ammonia plants were in no great hurry to reopen, and that meant many didn’t start supplying carbon dioxide in July, just when a huge heatwave hit the UK, coinciding with the World Cup football (which tends to generate a big demand for fizzy pop, for some reason).

Which brings us back to our atmosphere…

Carbon dioxide calamity?

Isn’t there, you may be thinking, too much carbon dioxide in our atmosphere? In fact, that heatwave you just mentioned, wasn’t that a global warming thing?  Can’t we just… extract carbon dioxide from our air and solve everyone’s problems? Well, yes and no. Remember earlier when I said that at the beginning of the twentieth century and atmospheric carbon dioxide levels were about 300 ppm (0.03%)?

Over the last hundred years atmospheric carbon dioxide levels have increased from 0.03% to 0.04%

Today, a little over 100 years later, levels are about 0.04%. This is a significant increase in a relatively short period of time, but it’s still only a tiny fraction of our atmosphere (an important tiny fraction nonetheless – we’ll get to that in a minute).

It is possible to distill gases from our air by cooling air down until it liquefies and then separating the different components by their boiling points. For example nitrogen, N2, boils at a chilly -196 oC whereas oxygen, O2, boils at a mere -183 oC.

But there’s a problem: CO2 doesn’t have a liquid state at standard pressures. It forms a solid, which sublimes directly into a gas. For this reason carbon dioxide is usually removed from cryogenic distillation mixtures, because it would freeze solid and plug up the equipment. There are other ways to extract carbon dioxide from air but although they have important applications (keep reading) they’re not practical ways to produce large volumes of the gas for the food and drink industries.

Back to the environment for a moment: why is that teeny 0.04% causing us such headaches? How can a mere 400 CO2 molecules bouncing around with a million other molecules cause such huge problems?

For that, I need to take a little diversion to talk about infrared radiation, or IR.

Infrared radiation was first discovered by the astronomer William Herschel in 1800. He was trying to observe sun spots when he noticed that his red filter seemed to get particularly hot. In what I’ve always thought was a rather amazing intuitive leap, he then passed sunlight through a prism to split it, held a thermometer just beyond the red light that he could see with his eyes, and discovered that the thermometer showed a higher temperature than when placed in the visible spectrum.

He concluded that there must be an invisible form of light beyond the visible spectrum, and indeed there is: infrared light. It turns out that slightly more than half of the total energy from the Sun arrives on Earth in the form of infrared radiation.

What has this got to do with carbon dioxide? It turns out that carbon dioxide, or rather the double bonds O=C=O, absorb a lot of infrared radiation. By contrast, oxygen and nitrogen, which make up well over 90% of Earth’s atmosphere, don’t absorb infrared.

CO2 molecules also re-emit IR but, having bounced around a bit, not necessarily in the same direction and – and this is the reason that tiny amounts of carbon dioxide cause not so tiny problems – they transfer energy to other molecules in the atmosphere in the process. Think of each CO2 molecule as a drunkard stumbling through a pub, knocking over people’s pints and causing a huge bar brawl. A single disruptive individual can, indirectly, cause a lot of others to find themselves bruised and bleeding and wondering what the hell just happened.

Like carbon dioxide, water vapour also absorbs infrared, but it has a relatively short lifetime in our atmosphere.

Water vapor becomes important here too, because while O2 and N2 don’t absorb infrared, water vapour does. Water vapour has a relatively short lifetime in our atmosphere (about ten days compared to a decade for carbon dioxide) so its overall warming effect is less. Except that once carbon dioxide is thrown into the mix it transfers extra heat to the water, keeping it vapour (rather than, say, precipitating as rain) for longer and pushing up the temperature of the system even more.

Basically, carbon dioxide molecules trap heat near the planet’s surface. This is why carbon dioxide is described as a greenhouse gas and increasing levels are causing global warming. There are people who are still arguing this isn’t the case, but truly, they’ve got the wrong end of the (hockey) stick.

It’s not even a new concept. Over 100 years ago, in 1912, a short piece was published in the Rodney and Otamatea Times which said: “The furnaces of the world are now burning about 2,000,000,000 tons of coal a year. When this is burned, uniting with oxygen, it adds about  7,000,000,000 tons of carbon dioxide to the atmosphere yearly. This tends to make the air a more effective blanket for the earth and to raise its temperature.”

This summer has seen record high temperatures and some scientists have been warning of a “Hothouse Earth” scenario.

This 1912 piece suggested we might start to see effects in “centuries”. In fact, we’re seeing the results now. As I mentioned earlier, this summer has seen record high temperatures and some scientists have been warning of “Hothouse Earth” scenario, where rising temperatures cause serious disruptions to ecosystems, society, and economies. The authors stressed it’s not inevitable, but preventing it will require a collective effort. They even published a companion document which included several possible solutions which, oddly enough, garnered rather fewer column inches than the “we’re all going to die” angle.

Don’t despair, DO something…

But I’m going to mention it, because it brings us back to CO2. There’s too much of it in our atmosphere. How can we deal with that? It’s simple really: first, stop adding more, i.e. stop burning fossil fuels. We have other technologies for producing energy. The reason we’re still stuck on fossil fuels at this stage is politics and money, and even the most obese of the fat cats are starting to realise that money isn’t much use if you don’t have a habitable planet. Well, most of them. (There’s probably no hope for some people, but we can at least hope that their damage-doing days are limited.)

There are some other, perhaps less obvious, sources of carbon dioxide and other greenhouse gases that might also be reduced, such as livestock, cement for building materials and general waste.

Forests trap carbon dioxide in land carbon sinks. More biodiverse systems generally store more carbon.

And then, we’re back to taking the CO2 out of the atmosphere. How? Halting deforestation would allow more CO2 to be trapped in so-called land carbon sinks. Likewise, good agricultural soil management helps to trap carbon underground. More biodiverse systems generally store more carbon, so if we could try to stop wiping out land and coastal systems, that would be groovy too. Finally, there’s the technological solution: carbon capture and storage, or CSS.

This, in essence, involves removing CO2 from the atmosphere and storing it in geological formations. The same thing the Earth has done for millenia, but more quickly. It can also be linked to bio-energy production in a process known as BECCS. It sounds like the perfect solution, but right now it’s energy intensive and expensive, and there are concerns that BECCS projects could end up competing with agriculture and damaging conservation efforts.

A new answer from an ancient substance?

Forming magnesite, or magnesium carbonate, may be one way to trap carbon dioxide.

Some brand new research might offer yet another solution. It’s another carbon-capture technology which involves magnesium carbonate, or magnesite (MgCO3). Magnesite forms slowly on the Earth’s surface, over hundreds of thousands of years, trapping carbon dioxide in its structure as it does.

It can easily be made quickly at high temperatures, but of course if you have to heat things up, you need energy, which might end up putting as much CO2 back in as you’re managing to take out. Recently a team of researchers at Trent University in Canada have found a way to form magnesite quickly at room temperature using polystyrene microspheres.

This isn’t something which would make much difference if, say, you covered the roof of everyone’s house with the microspheres, but it could be used in fuel-burning power generators (which could be burning renewables or even waste materials) to effectively scrub the carbon dioxide from their emissions. That technology on its own would make a huge difference.

And so here we are. Carbon dioxide is one of the oldest substances there is, as “natural” as they come. From breathing to fizzy drinks to our climate, it’s entwined in every aspect of our everyday existence. It is both friend and foe. Will we work out ways to save ourselves from too much of it in our atmosphere? Personally, I’m optimistic, so long as we support scientists and engineers rather than fight them…


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A Dash of Science, Social Media and VARD

Yesterday I recorded a podcast with Matthew Lee Loftus (from The Credible Hulk) and Christopher El Sergio for A Dash of Science, all about science communication and social media. It was a brilliant chat – I won’t go into lots of details of what we covered, but if you’d like to hear it (you know you do!) the direct link is: Communicating Science on Social Media. You can also pick it up on iTunes and/or Tune In.

After our conversation ended I remembered something I developed little while ago, after marking a particularly infuriating research homework where a quarter of the class wrote down that Mendeleev was awarded a Nobel prize for his work on the Periodic Table. For the record: he never received the honour. He was recommended for the prize but famously (at least, I thought it was famously!) the 1906 prize was given to Henri Moissan instead, probably due to a grudge held by Svante Arrhenius of Arrhenius Equation fame (it’s a good story, check it out).

Mendeleev was never awarded a Nobel prize.

Does it really matter if a few students believe that Mendeleev won a Nobel prize? That’s not really harming anyone, is it? Maybe not, but on the other hand, perhaps it’s part of a long and slippery slope greased with ‘alternative facts’ which is leading us to, well, shall we say, situations and decisions that may not be in our best interests as a society.

How to encourage students to do at least a little bit of fact-checking? Of course, you could produce a long list of Things That One Should Do to check information, but I reasoned that while students might read such a list, and even agree with the principles, they were unlikely to get into the habit of applying them and probably quite likely to immediately forget all about it.

Instead I tried to come up with something short, simple and memorable, and here it is (feel free to share this):

Fact-checking isn’t easy; it’s VARD

The four points I focused on spell out VARD, which stands for…

Verify

V is for verify, which means: can you find other sources saying the same thing? Now, chances are, you can always find something that agrees with a particular piece of information, if you look hard enough. There are plenty of sites out there that will tell you that lemons ‘alkalise’ the body, for example (they don’t), that it’s safe to eat apricot kernels (it’s not) and that black salve is an effective treatment for skin cancer (nope).

However, if you’re reasonably open-minded when you start, chances are good that you’ll find both sides of the ‘story’ and that will, at the very least, get you thinking about which version is more trustworthy.

Author

A is for author. I often hear swathes of content being disparaged purely based on its nature. You know the sort of thing: “that’s just a blog,” or “you can’t trust newspaper articles”. I think this is wrong-headed. What matters more is who wrote that piece and what are their qualifications? I’d argue that a blog post about medical issues written by a medical doctor (for example, virtually anything on the marvellous Science Based Medicine) is likely to be a pretty reliable source. Conversely, there’s been more than one thing that’s made it into the scientific literature which has later turned out to be flawed or even flat false (such as Wakefield’s famous 1998 paper). It’s also worth asking what someone’s background is: Stephanie Seneff, for example, is highly qualified in the fields of artificial intelligence and computer science, but does that mean we should trust her controversial opinions in biology and medicine? Probably not.

You may not always be able to tell who the author is, or have time to dig into their motivations, but it’s nevertheless a good question to keep in the back of your mind.

Reasonableness

Be honest: is that story really likely? Or is it just shocking?

R is for reasonableness. Which is a pain to spell or even say, but it’s important so I’m sticking with it. It’s a sense-check. Human beings love a good story, and the best stories have unexpected twists and turns. That’s why medical scare-stories pop up in newspapers with such depressing regularity. No, ketchup isn’t giving you cancer. No, our children really aren’t being poisoned by plastics. But the truth doesn’t always make a good headline. In fact, when it comes to science, the more some ‘exciting finding’ is plastered over news sites, the less you should probably trust it – because the chances are that the exciting version being reported bears almost no resemblance to the researchers’ original conculsions.

Be honest and ask yourself: does this really seem likely? Or would I just like it to be true because it’s a great story?

Date

If a surprising story has just appeared, give it twenty-four hours – chances are if there are major issues with the information someone else will come forward.

D is for date. The obvious situation is when information is so old that it’s been superseded by something else. This is easy: just look for something more recent. However, the other side of this coin is probably more relevant in these days of rolling news and instant sharing of articles: something can blow up at short notice, especially something topical, and it later turns out that not all the facts were known. Take, for example, the famous green swimming pools in the 2016 Olympics, which more than one writer attributed to copper salts in the pool water before the full facts were revealed a few days later. Inevitably, the ‘corrected’ version is far less interesting than the earlier speculation, and so that’s what everyone remembers.

If something controversial and shocking has just appeared, give it twenty-four hours. If there’s something terribly wrong with it, chances are someone will pick up on it in that time.

It’s not easy; it’s VARD

And that’s it: Verify, Author, Reasonableness, Date. It doesn’t cover every eventuality, but if you keep these points in the back of your mind it will definitely help you to separate the ‘probably true’ from the ‘almost certainly bollocks’.

Good luck out there!

Now why not go and listen to that podcast 🙂


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No element octarine, but Nanny will be pleased…

After lots of speculation over the last few months, the names of the new elements were finally announced by IUPAC yesterday. There will now be a five-month public review, ending on 8 November 2016, but it looks likely that these names will be accepted. They are:

  • 113: Nihonium, Nh, from ‘Nihon’, meaning Japan or ‘The Land of the Rising Sun’, home of RIKEN;
  • 115: Moscovium, Mc, in recognition of the Moscow region, where JINR is based;
  • 117: Tennessine, Ts, for the Tennessee region, home of ORNL;
  • and 118: Oganesson, Og, named after a very important individual*.
New-Element-Names-768x378

New Element Names, by Compound Interest (click image for more info)

As you can see, octarine sadly didn’t make the cut. Perhaps the million to one chance rule just doesn’t work so well on roundworld. Oh well.

But look, they didn’t completely forget about us! They just misspelled ‘Ogg and Son’. It’s easily done. I’m sure Nanny will still be pleased.

nanny_ogg_by_hyaroo-d6mnot6

Nanny Ogg. Image byHyaroo, http://hyaroo.deviantart.com/

*Oganesson actually recognises Professor Yuri Oganessian (born 1933) for his pioneering contributions to transactinoid elements research. But perhaps he’s a distant relative?


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Are we really wasting a valuable natural resource at parties?

Solar_eclipse_1999_4_NR

This particular inert gas was discovered by an astronomer observing a solar eclipse.

A couple of weeks ago I wrote a (tongue in cheek) post about a very inert gas, nitrogen. Silliness aside though, nitrogen is a bit, well boring. I mean, we’ve known about it for nearly 250 years, it makes up nearly 80% of our atmosphere and it mostly just sits around doing nothing. Even plants, who’ve mastered the spectacular trick of making solid stuff out of sunlight and carbon dioxide, can’t do much with it in its gaseous form (with a few exceptions).

There are much more interesting inert gases. There’s one that wasn’t even discovered on Earth. In fact, it was first spotted on the Sun by Jules Janssen, an astronomer who was taking advantage of a total solar eclipse to study the Sun’s atmosphere. After some more experiments astronomer Norman Lockyer and chemist Edward Frankland named the element after the Greek word for the Sun. It was the first element to be discovered somewhere other than Earth.

Helium_spectrum

Spectral lines of helium

As it turns out, this element is the second most abundant element in the universe (after hydrogen), but one of the least abundant elements on Earth – with a concentration of just 8 parts per billion in the Earth’s crust.

Today, almost all of us meet it as very young children. In balloons.

It’s helium, the second-lightest element in the periodic table and also, perhaps, the ultimate non-renewable resource.

Most of us meet this element as children.

We all learnt what ‘non-renewable’ means in school: it refers to something we’re using up faster than we can ever replace it. Almost anyone can tell you that crude oil is non-renewable. But the thing is, there are alternatives to crude oil. We can use bioethanolbiodiesel and their cousins to power vehicles and provide power. Bioethanol can act as a route to plastics, too. Scientists are also investigating the potential of algae to produce oil substitutes. These alternatives may (at the moment) be relatively expensive, and come with certain disadvantages, but they do exist.

We have no way to make helium. At least, no way to make it in significant quantities (it’s a by-product in nuclear reactors, but there we’re talking tiny amounts). And because it’s so light, when helium escapes into the atmosphere it tends to float, well, up. Ultimately, it escapes from our atmosphere and is lost. Every time you get fed up with that helium balloon that’s started to look a bit sorry for itself and stick a pin in it (perhaps taking a few seconds to do the squeaky-voice trick first) you’re wasting a little bit of a helium.

But so what? We could all live without helium balloons right? If we run out, balloons will just have to be the sinking kind. What’s the problem?

Liquid helium is used to cool the magnets in MRI machines.

Liquid helium is used to cool the magnets in MRI machines.

The problem is that helium has a lot more uses than you might realise. Cool it to -269 oC – just 4 degrees warmer than absolute zero, the lowest termperature there is – and it turns into a liquid, and that liquid is very important stuff. It’s used to cool the superconducting magnets in MRI (magnetic resonance imaging) scanners in hospitals, which provide doctors with vital, non-invasive, information about what’s going on inside our bodies. MRI techniques have made diagnoses more accurate and allowed surgery to become far more precise. Nothing else (not even the lightest element, hydrogen) has a lower boiling point than helium, so nothing else is quite as good for this chilly job. Scientists are working hard on developing superconducting magnets that work at warmer temperatures, but this technology is still in its infancy.

There’s another technology called NMR (nuclear magnetic resonance) which chemists use all the time to help them identify unknown compounds. In fact, MRI was born out of NMR – they’re basically the same technique applied slightly differently – but the medical application was renamed because it was felt that patients wouldn’t understand that the ‘nuclear’ in NMR refers to the nuclei of atoms rather than nuclear energy or radiation, and would balk at the idea of a ‘nuclear’ treatment. Possibly imagining that they’d turn into the Hulk when they went into the scanner, who knows.

Since it works in essentially the same way, NMR also relies on superconducting magnets, also often cooled with liquid helium. Without NMR, whole swathes of chemical research, not to mention drug testing, would run into serious problems overnight.

It doesn’t stop there. Helium is also used in deep-sea diving, in airships, to cool nuclear reactors and certain other types of chemical detectors. NASA also uses massive amounts of helium to help clean out the fuel from its rockets. In summary, it’s important stuff.

But if we can’t make it, where does all this helium come from?

The Earth’s helium supplies have largely originated from the very slow radioactive alpha decay that occurs in rocks, and it’s taken 4.7 billion years to build them up. Helium is often found sitting above reserves of natural oil and gas. In fact that’s exactly how the first helium reserve was discovered: when, in 1903, an oil drilling operation in Kansas produced a gas geyser that wouldn’t burn. It turned out that although helium is relatively rare in the Earth overall, it was concentrated in large quantities under the American Great Plains.

The National Helium Reserve

Show me the way to… The National Helium Reserve

Of course this meant that the United States quickly became the world’s leading supplier of helium. The US started stockpiling the gas during World War I, intending to use it in barrage balloons and later in airships. Helium, unlike the other lighter-than-air gas hydrogen, doesn’t burn. This made things filled with helium safer to handle and, of course, more difficult to shoot down or sabotage.

In 1925 the US government set up the National Helium Reserve in Amarillo, Texas. In 1927 the Helium Control Act came into force, which banned the export of the gas. At that point, the USA was the only country producing helium, so they had a complete monopoly (personally, I’d quite like to see a Monopoly board with ‘helium reserves’ on it, wouldn’t you?). And that’s why the Hindenburg, like all German Zeppelins, both famously and tragically had to use hydrogen as its lift gas.

Helium use dropped after World War II, but the reserve was expanded in the 1950s to supply liquid helium as a coolant to create hydrogen/oxygen rocket fuel during the Space Race and the Cold War. The US continued to stockpile helium until 1995. At which point, the reserve was $1.4 billion in debt. The government of the time pondered this and ended up passing the Helium Privatization Act of 1996, directing the United States Department of the Interior to empty the reserve and sell it off at a fixed rate to pay off the cost.

Right now, anyone can buy cheap helium in supermarkets and high street shops.

Right now, anyone can buy cheap helium in supermarkets and high street shops.

As a result cheap helium flooded the market and its price stayed fairly static for a number of years, although the price for very pure helium has recently risen sharply. This sell-off is why we think of helium as a cheap gas; the sort of thing you can cheerfully fill a balloon with and then throw away. Pop down to a large supermarket or your local high street and you might even be able to buy a canister of helium in the party section relatively cheaply.

The problem is that this situation isn’t going to last. The US reserves have been dramatically depleted, and at one point were expected to run out completely in 2018, although other reserves have since been discovered and other countries have set up extraction plants. It is also possible to extract helium from air by distillation, but it’s expensive – some 10,000 times more expensive. None of these alternatives are expected to really ease the shortage; they’ll just delay it by a few years.

So are helium party balloons truly an irresponsible waste of a precious resource? Well… the helium that’s used in balloons is fairly impure, about 98% helium (mixed with, guess what? Yep, we’re back to nitrogen again!) whereas the helium that’s needed for MRI and the like is what’s called ‘grade A’ helium, which is something like 99.997% pure, depending on whom you ask. Of course you can purify the low-grade helium to get the purer kind but this costs money, which is why grade A helium is so much more expensive.

NABAS logo

The National Balloon Association (‘the voice of the balloon industry’ – you can’t help wondering whether that’s a very high-pitched voice, can you?) argues that balloons only account for 5-7% of helium use and that the helium that goes into balloons – which they prefer to call ‘balloon gas’ because of its impurities – is mainly recycled from from the gas that’s used in the medical industry, or is a by-product of supplying pure, liquid helium, and therefore using it in balloons isn’t really a problem.

Dr Peter Wothers argues that helium balloons should be banned.

Dr Peter Wothers argues that helium balloons should be banned.

On the other hand, more than one eminent physics professor has spoken out on the subject of helium wastage. It costs about 30-50p to fill a helium balloon, but Professor Robert Richardson of Cornell University argued (before his death in 2013) that a helium party balloon should cost £75 to more accurately reflect the true scarcity value of the gas. Dr Peter Wothers of Cambridge University has called for an outright ban of them, saying that in 50 years’ time our children will be amazed that we ever used such a precious material to fill balloons.

Is it time to call for a helium balloon boycott? Perhaps, although it will probably take more than one or two scientifically-minded consumers refusing to buy them before we see any difference. Realistically, the price will sky-rocket in the next few years and, as Peter Wothers suggests, filling balloons with helium will become a ridiculous notion because it’s far too expensive.

Will images like this make no sense in the future?

Will images like this make no sense in the future?

It’s strange to think though, that in maybe 50 years or so the idea of a floating balloon might simply disappear. Just think of all the artwork and drawings that will no longer make sense.

Perhaps this quotation by the late Sir Terry Pratchett is even more relevant than it first appears:

“There are times in life when people must know when not to let go. Balloons are designed to teach small children this.”

———

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Is a noxious gas really being added to your food?

Daniel Rutherford named nitrogen "noxious air".

Daniel Rutherford named nitrogen “noxious air”.

Today I’m writing about a potentially dangerous, but surprisingly rarely discussed, substance. It’s a gas at room temperature, with a molecular mass of 28. It sits next to oxygen in the periodic table, but these two could not be more different. When it was discovered by Daniel Rutherford in 1972 he named it ‘noxious air’. Other scientists called it ‘burnt air’, ‘mephitic air’, and ‘azote’ – from the Greek word meaning lifeless – because animals died when they were exposed to it. Today we call it nitrogen.

Let me tell you more. It’s an industrial chemical which is used to make fertilisers and explosives, and to fill tyres. Does that sound like something that you should be exposed to on a daily basis?

Nitrogen is used to fill aeroplane and car tyres.

Nitrogen is used to fill aeroplane and car tyres.

Well I’ve got news for you, you are. Nitrogen is in the air around us. That’s right, this gas which, let me reiterate, was discovered when it was found to kill small animals, is all around us. The concentration of it is fairly stable now, but it has increased dramatically in Earth’s past.

NitrogenRencer

A nitrogen molecule. Not actual size.

Breathing air with more than about 0.8 bar partial pressure will make you really ill or even kill you and yet, pure nitrogen is regularly used to package our foods. Those salad bags you thought were so fresh and healthy? Full of pure nitrogen. That nitrogen is obtained by a process known as fractional distillation. Petrol, diesel and bitumen – the stuff used to cover our roads – are produced by exactly the same method.

Nitrogen is invisible, tasteless and odourless, and companies don’t have to label it on their packaging. Some of the more reputable manufacturers do state that their food is ‘packaged in a protective atmosphere’, but since there is no regulation to force companies to include this label, its absence is no guarantee. You could be eating nitrogen-drenched lettuce right now, and you’d have no idea. And for those salad-dodgers out there breathing a sigh of relief, crisps (chips, for my American readers) are also packaged in this stuff.

Nitrogen can be used in food preparation.

Nitrogen is often used in over-priced food preparation.

It gets worse. When it’s cooled nitrogen becomes a liquid, and this form is also used in food preparation. Some chefs have famously used it to make gourmet ice-cream. But in its liquid form nitrogen is even more dangerous. It’s extremely volatile. Exposure to liquid nitrogen causes severe and painful burns which can leave permanent scars. People who need to handle it should wear thick, industrial-strength gloves and eye protection. It’s so dangerous that one Australian liquor authority recently ordered bars to stop serving drinks containing liquid nitrogen after a patron became seriously ill.

Surely we should be asking the question: should something this harmful REALLY be involved in food preparation at all, anywhere in the world?

Screen Shot 2015-03-31 at 23.20.43

The Food Doll. She knows about this stuff.

Health food campaigners and ‘wellness warriors’ are increasingly setting their sites on this new menace. In an interview, ‘Food Doll’ Eyna Noscience said, “During my research into this stuff I found out that food companies sometimes mix it with carbon dioxide, and we all know that’s killing the ozone layer. We should all be campaigning for better labelling.”

She went on to add: “It’s a pnictogen. I don’t know what that means, but it sounds suspiciously like carcinogen to me. Nothing that unpronounceable can be good for you, right? I always say, if you can’t read it, you shouldn’t be eating it. Or breathing it.”

The spectrum of nitrogen. It's totally irrelevant but it is pretty.

The spectrum of nitrogen. It’s totally irrelevant but it is pretty.

Great-student-demonstration-slogans-ladynottingham-17775214-500-334

Cease the Ugly Nitrogen Terror campaigners staged a peaceful demonstration, and were arrested for “offensive slogans” (not shown).

Despite clearly knowing nothing whatsoever about anything, it’s possible that Eyna Noscience has a point. Perhaps consumers should have the choice over whether they want to buy products saturated with nitrogen? The organisation Cease the Ugly Nitrogen Terror certainly think so. They recently held a peaceful demonstration outside a well-known supermarket in London. Several of their supporters, who were holding placards bearing the initials of the organisation, were arrested for allegedly “offensive slogans”. Clearly yet another example of the food industry having far too much power.

What do you think? Should nitrogen be banned from foods? Leave your comments below.

GNU Terry Pratchett.

—————–

Note: now, in case it’s not entirely obvious, this post is a joke (I say this because some people have asked me, believe it or not). But truth, as they say, is stranger than fiction. After I wrote this I found out that the ‘Food Babe’, aka Vani Hari, had actually written a post (she has since deleted it, but the internet is great for making it difficult to hide such things) in which she demonstrated a fabulous misunderstanding of chemistry and physics. In particular (from here, 6th paragraph):

“The air you are breathing on an airplane is recycled from directly outside of your window. That means you are breathing everything that the airplanes gives off and is flying through. The air that is pumped in isn’t pure oxygen either, it’s mixed with nitrogen, sometimes almost at 50%. To pump a greater amount of oxygen in costs money in terms of fuel and the airlines know this! The nitrogen may affect the times and dosages of medications, make you feel bloated and cause your ankles and joints swell.”

I don’t know about everyone else, but personally I’d be a bit worried about a 50% oxygen atmosphere, particularly in an aeroplane. Let’s just hope she’s wrong, eh?

The Chronicle Flask’s festive chemistry quiz!

Tis the season to be jolly! And also for lots of blog posts and articles about the science of christmas, like this one, and this one, and this one, and even this one (which is from last year, but it’s jolly good).

But here’s the question: have you been paying attention? Well, have you? Time to find out with The Chronicle Flask’s festive quiz! I haven’t figured out how to make this interactive. You’ll have to, I don’t know, use a pen and paper or something.

Arbol_de_navidad_con_adornos_de_personajesQuestion 1)
Which scientist invented a chemical test that can be used to coat the inside of baubles with silver?
a) Bernhard Tollens
b) Karl Möbius
c) Emil Erlenmeyer

Question 2)
Reindeer eat moss which contains arachidonic acid… but why is that beneficial to them?
a) a laxative
b) an anti-freeze
c) a spider repellant

1280px-ChristmasCrackers_2Question 3)
Which chemical makes crackers and party poppers go crack?
a) gunpowder
b) silver fulminate
c) nitrogen triiodide

640px-Glass_of_champagneQuestion 4)
We all like a glass of champagne at this time of year, but what’s in the bubbles?
a) carbon dioxide
b) nitrogen
c) oxgyen

Question 5)
What’s the key ingredient in those lovely bath salts you bought for your grandma?
a) calcium carbonate
b) magnesium sulfate
c) citric acid

The Bird - 2007Question 6)
Which chemical reaction is responsible for both perfectly browned biscuits and crispy, golden turkey?
a) Maillard reaction
b) Hodge reaction
c) Caramel reaction

Question 7)
Sucrose-rodmodelWhere are you most likely to find this molecule at this time of year?
a) in a roast beef joint
b) in the wrapping paper
c) in the christmas cake

Question 8)
Let it snow, let it snow, let it snow… but which fact about (pure) water is true?
a) It glows when exposed to ultraviolet light
b) It expands as it freezes
c) It’s a good conductor of electricity

Ethanol-3D-ballsQuestion 9)
Where are you likely to find this molecule on New Year’s Eve?
a) in a champagne bottle
b) in the party poppers
c) in the ‘first foot’ coal

OperaSydney-Fuegos2006-342289398Question 10)
Who doesn’t love a firework or two on New Years Eve?  But which element is most commonly used to produce the colour green?
a) magnesium
b) sodium
c) barium

(Answers below…)

1a) Bernhard Tollens (but his science teacher was Karl Möbius).
2b) It’s a natural anti-freeze.
3b) Silver fulminate (it always surprises me how many people guess gunpowder. That would be exciting).
4a) carbon dioxide.
5b) magnesium sulfate which, funnily enough, also causes ‘hard’ water.
6a) the Maillard reaction, although Hodge did establish the mechanism.
7c) In the cake – it’s sucrose (table sugar).
8b) it expands as it freezes and is thus less dense than liquid water (which is why ice floats). We take this for granted, but most things contract (and become more dense) as they turn from liquid to solid. You should be grateful – live probably wouldn’t have evolved without this peculiar behaviour.
9a) In the champagne – it’s ethanol (or ‘alcohol’ in everyday parlance).
10c) barium – copper produces green flames too, but barium salts are more commonly used in fireworks.

So how did you do?
Less than 4: D, for deuterium. It’s heavy hydrogen and it’s used to slow things down. Enough said.
4-6: You get a C, by which I mean carbon. Have another slice of coal.
7-8: You’ve clearly been paying attention. B for boring, I mean boron.
9-10: Au-ren’t you clever? Chemistry champion!

Happy New Year everyone! 🙂

Why weigh atoms that way?

A couple of days ago I was listening to the latest Radiolab podcast. If you’ve never listened to one of these, you really should. They are beautifully produced and, without fail, utterly fascinating. Over the last year or so I’ve learned about a possible cure for a disease with a 100% mortality rate, an apocryphal Russian story about horses frozen into a block of ice, and a new theory for the end of the dinosaurs where, if I understood it correctly, they were essentially grilled to death. Episodes of Radiolab always feel like a thoroughly good use of brain-time.

Anyway, if you’re still with me and haven’t dashed off to immediately download some of these little gems, the most recent episode is about weights and measures and how we’ve standardised them over the years. In particular the kilogram, which is the last physical standard in use, although possibly not for long (listen to the podcast).

shutterstock_27019597_Alhovik_mod_2

So what are the scales made of…?

This got me thinking about atoms and, in particular, how we decide their mass. This matters you see, because the mass of atoms tells us chemists how much stuff to use. If I want a saline solution with a particular concentration, all I need do is look up the numbers on the periodic table, weigh out the appropriate amount of salt and dilute it with the appropriate amount of water. And if you’re a patient who needs a saline drip, you’d better hope I did it correctly.

Anyway, if you remember your periodic table (which of course you do, but just in case, here’s a picture) all the elements come with two numbers.

The Periodic Table

One of these numbers is the atomic number, which is the number of protons in the nucleus of each atom of the element. Conveniently, nature has managed to produce an atomic nucleus for each number between 1 and, at last count, 118 and if you ‘read’ the periodic table from left to right, top to bottom, you’ll see the numbers go up one at a time.

The other number, relative atomic mass, is a bit less tidy. It still goes up as you go along the periodic table, but in less regular jumps of roughly between one and three.  Without going into lots of detail, relative atomic mass is standardised against 112 the mass of carbon-12. Which begs the question, why? The more mathematically aware will have clocked that 112 of 12 is, well, 1. So why don’t we compare all the elements to hydrogen, which actually has a mass of 1? Or if that’s infeasible for some reason why not, I don’t know, choose 19 of beryllium-9, or 128 of silicon-28?

Well actually, almost exactly 200 years ago now, atomic mass (called atomic weight, at the time) was originally compared to hydrogen, and it was thought that all elements would have masses which were exact multiples of hydrogen’s.

The problem with this was that as measuring techniques became more sophisticated it became clear that some elements were inconveniently failing to follow the rule. In fact, some were downright contrary, like chlorine which appeared to have a mass which wasn’t even a whole number.

This was, at least partially, sorted out in 1932 when James Chadwick proved the existence of neutrons. The existence of isotopes had already been suggested, but this finally cleared up what the pesky things actually were. It turns out some atoms are fatter than others, having one or two more uncharged particles in their nuclei. This doesn’t change what atom they are – they still have the same number of protons – but it does make them a bit heavier. Take a sample of pure chlorine, for example, and you find that roughly three quarters of the atoms in it have a mass of 35, whereas the other quarter have a mass of 37. These are the isotopes of chlorine: imaginatively named chlorine-35 and chlorine-37. Work out the weighted average of the two and you get 35.5, which is the number you see on periodic tables.

In the mid-20th century something of a minor squabble between chemists and physicists broke out (chemists and physicists often squabble: they’re a bit like the English and the French: they like to visit each other but only so that they can moan about how annoying the other lot are and how badly they do everything). By this time had been a switch from using hydrogen (the lightest element) to oxygen as the standard to which other elemental masses were compared. This was mainly for the convenience of chemical analysis: oxygen combines with a lot of things to make straightforward oxides, whereas hydrides are less common and trickier to work with. Plus, large quantities of hydrogen gas are a bit (in the sense of an elephant being a bit heavy, or cyanide being a bit poisonous) of an explosion risk. Oxygen causes other things to burn jolly nicely, but isn’t actually flammable itself. If you can manage to keep it away from other flammable stuff it’s a far safer option.

The problem was that chemists were using a mass scale based on assigning the number 16 to a natural mixture of oxygen (which contains mostly oxygen-16, with little bits of oxygen-17 and oxygen-18). Physicists, on the other hand, had instead assigned the number 16 to the isotope oxygen-16, which they had isolated using the technique of mass spectrometry.

Josef Mattauch

Physicist Josef Mattauch

You may think the physicists’ method sounds more logical, but the chemists’ reasoning was that in naturally-occurring compounds there would be a mixture of isotopes, so it made sense to use a number based on that mixture since you never actually encounter one atom on its own. Either way, the result was differences in the numbers, admittedly some way down the decimal places, but none the less a difference. Of course it was possible to convert between the two, but at the time scientists were fiddling with such tricksy things as nuclear energy and, of course, bombs. Even a tiny discrepancy in the nth decimal place was potentially catastrophic. Something had to be done.

Edward_Wichers

Chemist Edward Wichers

In 1961 a compromise was agreed, thanks largely to the combined efforts of the physicist Josef Mattauch and the chemist Edward Wichers, who set about persuading their respective groups to be reasonable and play nicely with each other.

The result was that carbon-12 was assigned a mass of exactly 12 and the relative atomic mass scale became based on that. The choice of carbon was, to an extent, somewhat arbitrary. It suited the physicists, who were already using carbon as a standard for mass spectrometry. It fell in between the two previous values (1 for hydrogen and 16 for oxygen), which meant it wouldn’t throw every existing piece of work out by too much. In particular, chemists weren’t keen on switching to the physicists’ method of 116 of the oxygen-16 isotope, because it would change their numbers quite significantly. Switching to 112 of carbon-12 meant, surprisingly, a smaller change. Carbon is also, of course, a naturally abundant element and it was easy to get samples of pure carbon.

And that, as they say, is that. The carbon-12 scale is still used today, over 50 years later, and it’s not going anywhere. Hydrogen is officially 112 the mass of carbon-12, and we use carbon-12 because, basically, it was the only option the chemists and physicists would agree on. Hey, it’s as good a reason as any.

Phabulous phenol

I was thinking about phenol the other day. “Very interesting,” I hear you say, “now if you don’t mind I’ve got a fascinating patch of drying paint I need to keep an eye on.” But wait! Bear with me. Phenol is a very interesting molecule. It’s history has a little something for everyone, from lawyers to doctors to advertising copywriters. There are gruesome tales from history, legal wrangles, and even a warning about the dangers of believing everything you read on the internet. So drag yourself away from the eggshell white, find yourself a comfy seat and I’ll begin.

Phenol

Phenol: a simple molecule with a complicated history.

Phenol is a simple molecule, consisting of a single -OH group attached to what chemists call a benzene ring (the structure of which was, so legend has it, finally determined after the German chemist August Kekulé dreamt of a snake eating its own tail).

You may think you’ve never heard of phenol, less still used it, but chances are you’ve come across the term ‘carbolic soap‘ somewhere. Phenol’s other name is carbolic acid, and it’s the main ingredient in carbolic soap, a mildly disinfectant cleaning agent that used to be a common household product in both Britain and America (in the form of Lifebuoy), was widely used in English state schools up until at least the 1970s, and is distributed to disaster victims for routine hygiene by the Red Cross to this day.

Carbolic soap isn’t so common these days since it has a tendency to irritate the skin and far gentler alternatives are available, although you can still find it in specialist outlets and apparently it’s quite popular in the Caribbean.

Friedlieb Ferdinand Runge

Friedlieb Ferdinand Runge

But back to phenol itself. It was discovered in 1834 when it was extracted from coal tar – a by-product of the coal industry – by the chemist Friedlieb Ferdinand Runge, also famous for identifying caffeine.

434px-Joseph_Lister2

Joseph Lister

Despite his rather glorious name, Runge is not the best-remembered scientist associated with phenol. That honour almost certainly goes to Joseph Lister who, in the late 19th century, pioneered the technique of antiseptic surgery. It may seem difficult to believe today, but back then surgeons weren’t required to wash their hands before treating patients, and even took pride in the accumulated stains on their surgical gowns. Until Lister’s use of phenol (or carbolic acid), people were more likely to die from infection following the treatment than from the original injury itself. Lister started using phenol to sterilise surgical instruments and wounds and after seeing his results others soon followed, completely changing surgery as we know it today.

In case you’re wondering, Lister had nothing directly to do with the invention of the (phenol-free) mouthwash product that bears his name. It was, however, named after him in honour of his work. Interestingly, Listerine was first marketed as a surgical antiseptic, then a floor cleaner and a cure for gonorrhoea, before it eventually found success as a solution for bad breath.

carbolic smoke ballI mentioned lawyers earlier, and that’s because phenol was instrumental in one of the first examples of contract law: Carlill v Carbolic Smoke Ball Company [1892]. It was the main ingredient of the Carbolic Smoke Ball, an ineffective piece of medical quackery marketed in London in the 19th century as protecting the user against influenza and other ailments. The manufacturer advertised that buyers who found it did not work would be awarded £100.

The Carbolic Smoke Ball Company thought this was nothing more than an inspired piece of advertising, and tried to argue that it was “mere puff” that no reasonable person would take literally. The judge rejected their claims, ruled that the advert made an clear promise, and ordered the company to pay £100 to the unfortunate flu-suffering customer Louisa Carlill. To this day, this case is often cited as an example of the basic principles of contract and how they relate to every day life.

Picture1

St. Maximilian Kolbe

Phenol also has a darker past, injections of it having been used as a means of execution. In particular, in World War II the Nazis used it in the euthanasia program, Action T4. Phenol was inexpensive, easy to make and fast-acting, and so quickly became the injectable toxin of choice. Famously, the Polish Catholic priest St. Maximilian Kolbe volunteered to undergo three weeks of starvation and dehydration in the place of another inmate and was ultimately executed by phenol injection. Kolbe was canonized on 10 October 1982 by Pope John Paul II; he is the patron saint of drug addicts.

Anyone who’s ever used phenol has probably experienced a phenol burn at some point. It doesn’t always hurt immediately but it slowly starts to burn after a little while, leaving white marks that ultimately turn red and slough off leaving brown-stained skin behind. It is, I should stress, not to be messed with – absorption of phenol through skin can result in phenol toxicity, and if left on the skin it can lead to cell death and gangrene. Even a tiny not-even-remotely-lethal spot is really quite painful. I can’t begin to imagine what death from phenol injection must have been like.

5012616170409Let’s end on a slightly lighter note. Have you got a bottle of TCP in your medicine cabinet? Many have fallen into the trap of believing that its initials relate directly to its ingredients, and specifically 2,4,6-trichlorophenol. In fact, a number of chemistry textbooks have stated this as hard, cold fact, as did a number of other online sources.

Not so, TCP originally contained trichlorophenylmethyliodosalicyl (not the same thing, and actually some have even wondered if this is truly a compound), but even that was replaced by other active ingredients in the 1950s. These days TCP contains a dilute solution of phenol (about 0.175% w/v) and halogenated phenols (0.68 w/v). So after all that, it does have phenol in it, but it’s not clear whether ‘halogenated phenols’ includes 2,4,6-trichlorophenol.

For a long time many, many websites stated that TCP contained trichlorophenylmethyliodosalicyl, probably traceable back to an earlier Wikipedia article (Wikipedia’s information has since been updated). As Jim Clark points out on his excellent Chemguide website, “The internet is a potentially dangerous tool. One single bit of misinformation can get multiplied over huge numbers of web sites”.

It’s true. Trust no one. (Except The Chronicle Flask of course*.)

(* If you spot an inaccuracy do let me know…)

Green hair and airborne wasabi: the Ig Nobel prizes

Next week on September 12th some extremely important prizes are about to be awarded that will undoubtedly rock the scientific community. Yes indeed, it’s that time again: the annual Ig Nobel prize award ceremony.

I first met the Igs about 15 years ago when I went to a conference in Seattle ig-nobel(yes I’m that old). The talk was a popular one, the Igs being a bit of light relief from all the serious science being discussed. That year there were awards for the development of a suit of armor impervious to grizzly bears, a study on the relationship between height, foot size and penile length (admit it, you’ve always wanted to know) and Jacques Benveniste of France, for his homeopathic ‘discovery’ that not only does water have memory, but that the information can be transmitted over telephone lines and the Internet (hmm).

So what are they, exactly? Some describe them as parodies of the official Nobel prizes. Home of the Igs AIR, the Annals of Improbable Research, describes them as awards for research that makes people laugh, and then think. Sometimes, as in the case of Benveniste, an Ig is awarded to someone for their, shall we say, excessively creative application of scientific ideas. More often these days they are awarded to scientists who’ve worked on something rather weird and wonderful, but which actually turns out to have some interesting applications.

So, since this is a chemistry blog, what have the last few Ig Nobel Chemistry prizes been awarded for?

2012Johan Pettersson, for solving the puzzle of why, in certain houses in the town of Anderslöv, Sweden, people’s hair turned green.
A great story, this: Several formerly blonde inhabitants of Anderslöv in southern Sweden suddenly acquired new green hairdos. Initially suspicion fell to the water supply, specifically copper contamination, since copper is known to dye hair green. But the problem was only affecting certain households. Testing revealed that copper levels were normal in the water supply itself, however when the water sat in the pipes in some recently-built houses overnight the copper levels rocketed. Why? Copper pipes in the new houses weren’t coated on the inside, so copper was leaching into the water. Residents who’d rather not have green hair have been told to wash their hair in cold water.

2011: Makoto Imai, Naoki Urushihata, Hideki Tanemura, Yukinobu Tajima, Hideaki Goto, Koichiro Mizoguchi and Junichi Murakami, for determining the ideal density of airborne wasabi to awaken sleeping people in case of a fire or other emergency, and for applying this knowledge to invent the wasabi alarm.
In this case the title says it all. As anyone that’s ever eaten a lump of that green stuff that comes with sushi knows, if wasabi gets into your nasal passages you know about it. The researchers worked out exactly how much wasabi would need to be in the air for it to be intolerable, and then developed and patented an alarm system that releases that concentration of wasabi in case of emergency. Well, at least it won’t wake up the neighbours.

2010: Eric AdamsScott SocolofskyStephen Masutani, and BPfor disproving the old belief that oil and water don’t mix.
A silly title with a serious motive, oil spills being something of a big deal. A team of scientists conducted controlled discharges of oil and water in the Norwegian sea at a depth of 844 meters and demonstrated that most oil from a spill in the deep ocean would in fact mix with water, rather than rise directly to the surface. The decision to award the prize jointly to BP, given the recent Deepwater Horizon incident, was particularly cutting.

2009: Javier MoralesMiguel Apátiga, and Victor M. Castañofor creating diamonds from liquid — specifically from tequila.
This might just be my favourite. It sounds ridiculous, and yet they published a serious paper. Scientists have long used various solvent mixtures to grow thin diamond films, and the researchers in this case were experimenting with mixtures of ethanol (‘drinking’ alcohol) and water. They noticed that the mixture that produced the best results had a similar composition to tequila, and so decided to experiment with the alcoholic beverage. It turned out that some types of tequila really did have exactly the right mixture of carbon, hydrogen and oxygen to promote growth of the films.

2008: Sharee A. Umpierre, Joseph A. Hill, Deborah J. Anderson and Harvard Medical School, for discovering that Coca-Cola is an effective spermicide, and to Chuang-Ye Hong, C.C. Shieh, P. Wu, and B.N. Chiang for discovering that it is not. 
The mind boggles, doesn’t it? There are many myths associated with pregnancy, and what does and doesn’t prevent it. No one would seriously recommend Coca-Cola as a contraceptive. However the first set of researchers decided to look into the question in a little more depth. They tested small samples of sperm with different types of Coca-Cola and found that they did, indeed, kill some sperm. However their results couldn’t be reproduced by the second set of scientists, who concluded that if Coke did have a spermicidal effect it was weak – little different to their control sample. A Coca-Cola spokesperson responded that “we do not promote any of our products for any medical use”. Glad they cleared that up.

You can see the full list of Ig Nobel prize winners here. The 2013 Ig Nobel prizes will be announced on Thursday September 12, 2013. You can join in on Twitter with the hashtag #IgNobel, and there’s also a webcast at 5:30pm EDT, which if my calculations are correct is 10:30am over here in the UK. I wonder what will be recognised this year…

Gold! Bright and yellow, hard and cold

200px-Gold-49956Let’s talk about element number 79.  It’s one of the oldest known elements, used for quite literally thousands of years.  It’s constantly at the heart of conflicts and politics.  Poets have waxed lyrical about it, authors have written about it, economists and prospectors have hinged their livelihoods on it.  And, of course, chemists have studied it.

As an element it’s unusual.  It’s a metal, but instead of the boring silvery-grey of most metals it glows a warm yellow.  It’s also one of the most unreactive elements, and yet has found use a catalyst – speeding up chemical reactions that otherwise would be too slow to be useful.  It’s rare, making up only about 0.004 parts per million of the Earth’s crust, and yet its annual production is surprisingly high: 2700 tonnes in 2012.  Its density makes it heavy – weighing over nineteen times more than the same volume of water – but it’s also relatively soft, so soft that it’s possible to scratch a pure piece with your fingernail (in theory, and if you have fairly robust fingernails).

Yes, gold.  Chemical symbol Au, from its latin name aurum meaning ‘shining dawn’ or ‘glow of sunrise’ (how lovely is that?)

The history of gold is fascinating.  You could easily write a whole book about it.  In fact, someone has.  I won’t attempt anything so ambitious, but it does have some very interesting chemical stories associated with it.

Because of its unreactivity, gold is one of the relatively few elements that’s found uncombined in nature.  In other words, you can pick up a piece of pure gold from the ground or, more likely, out of a river bed.  Thanks to this property it’s very probably the first metal that humans as a species interacted with.  It’s too soft to be much use as a tool, so its earliest uses were almost certainly ornamental.  Decorations and jewellery had value and could be traded for other things, and ultimately (skipping over a chunk of history and early economics) this led to currency.

And so it was that early alchemists, some two thousand years ago, became obsessed with the idea of a quick buck.  Could other metals be turned into gold?  They searched long and hard for the mythical philosopher’s stone (like in Harry Potter, only not exactly) which could turn base metals into gold or silver.  Of course they never found it, because it doesn’t exist.  It’s not possible to change one element into another during a chemical reaction.  This is because what defines an element is the number of protons in its nucleus, and chemistry is all about the electrons. Chemical processes don’t touch protons, which are hidden away in the nuclei of atoms.

But where there’s a will there’s almost always a way.  Two millennia after alchemists were hunting for a magical stone, the chemist Glenn Seaborg managed to transmute a minute quantity of lead, via bismuth, into gold by bombarding it with high-energy particles.  Apparently, these days particle accelerators ‘routinely’ transmute elements, albeit only a few atoms at a time.

The trouble is, this method costs a fortune – way, way more than the value of any gold produced.  Gold, after all, is ‘only’ worth about a thousand pounds for a troy ounce (31 grams).  Particle accelerators cost billions of pounds to build, and yet more in running costs.  If you really want gold so desperately, these days there may be more mileage in harvesting it from defunct bits of electronic equipment.

Or just ask people to send you their old jewellery through the post in exchange for cash.  Even Tesco have got into that game now.  Through the post!  Honestly, people fear putting a tenner in a birthday card but gold jewellery in a paper bag?  No problem.

But anyway, back to gold’s reactivity, or rather lack of it.  Gold isn’t the most unreactive element (depending on how you’re defining reactivity, that honour probably goes to iridium) but it’s up there.  Or perhaps I should say down there.  It keeps its shiny good looks even when it’s regularly in contact with warm, damp, salty, slightly acidic skin, which is quite handy from the jewellery and money point of view.

But there is one thing gold reacts with: aqua regia.  Aqua regia is a mixture of nitric and hydrochloric acid and ancient alchemists gave it its name – which literally means ‘royal water’ – because it dissolves the ‘royal’ metal, gold.  It’s pretty cool stuff, in a slightly scary way.  Freshly-prepared it’s colourless, but quickly turns into a fuming, reddish solution.  It doesn’t keep – the hydrochloric and nitric acids effectively attack each other in a series of chemical reactions which ultimately result in the production of nitrogen dioxide, accounting for the orange colour and nasty fumes. Screen Shot 2013-06-04 at 00.20.27The fire diamond (remember those?) for aqua regia has a 3 in the blue box, putting it on a nastiness par with pure chlorine, ammonia and, funnily enough, oxalic acid (the stuff in rhubarb).  It also has ‘ox’ in the white box, telling us it’s a powerful oxidising agent, which means it’s effectively an electron thief.

All atoms contain electrons but they can, and frequently do, lose or gain them during the course of chemical reactions.  Acids in general are often quite good at pinching electrons from metals, but aqua regia is particularly good at it, and especially with gold.  Much, much better than either nitric acid or hydrochloric acid on their own because, in fact, the two work together, as a sort of two-man gang of acid muggers.  When metal atoms lose electrons they become ions, and ions dissolve very nicely in water.  Hence, aqua regia’s fantastic property of being able to dissolve gold.

Which leads me to a really great story.  During World War II it was illegal to take gold out of Germany, but two Nobel laureates – Max von Laue, who strongly opposed the National Socialists, and James Franck, who was Jewish – discretely sent their 23-karat, solid gold Nobel prize medals to Niels Bohr’s Institute of Theoretical Physics in Copenhagen for protection.  All well and good, until the Nazis invaded Denmark in 1940.  Now, unfortunately, the evidence of von Laue and Franck’s crime was sitting on a shelf in a lab, just waiting to be found.  This was serious: if the Gestapo found the gold medals they would persecute von Laue and Franck, and probably take the opportunity to make things very unpleasant for Bohr as well, particularly since his institute had protected and supported Jewish scientists for years.

Nobel_PrizeWhat to do?  At the time a Hungarian chemist called George de Hevesy was working at the institute, and it was he that had the bright idea of dissolving the medals in aqua regia.

It would have taken ages, because although aqua regia dissolves gold, it doesn’t do it quickly, and these were chunky objects.  He must have been anxiously looking over his shoulder the whole time.  But he managed it, and eventually ended up with a flask of orange liquid that he stashed on a high shelf.  The Nazis searched the building but didn’t realise what the flask was, so they left it.  Iit stayed there undisturbed for years, in fact until after the war was over.  At which time, de Hevesy precipitated the gold back out and sent the metal back to the Swedish Academy, who recast the prizes  and re-presented them to Franck and von Laue.

So there we have it, you can’t turn lead into gold (at least, not without a particle accelerator) but, if you know what you’re doing, you might just be able to turn a flask of orange liquid into two solid gold Nobel prize medals!

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The title of this post comes from a poem by the British poet, Thomas Hood, 1799-1845. Here it is in full:

Gold!
Gold! Gold! Gold! Gold!
Bright and yellow, hard and cold
Molten, graven, hammered and rolled,
Heavy to get and light to hold,
Hoarded, bartered, bought and sold,
Stolen, borrowed, squandered, doled,
Spurned by young, but hung by old
To the verge of a church yard mold;
Price of many a crime untold.
Gold! Gold! Gold! Gold!
Good or bad a thousand fold!
How widely it agencies vary,
To save – to ruin – to curse – to bless –
As even its minted coins express :
Now stamped with the image of Queen Bess,
And now of a bloody Mary.