Category Archives: Science

Th’ Gaussling’s 14th Epistle to the Bohemians. Enjoy the Ineffable.

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Here is a great title for a post- “Effing the Ineffable“.  I wish I’d thought of it.  The author, Roger Scruton, a philosopher, attempts to circumscribe the indescribable and unquantifiable by revealing those who have tried to describe the ineffable. His conclusion is to relent and accept it.  

Having a brain and sensing the external world means that our sensory apparatus and our internal private monolog are interpreting a continuous stream of perceptual input whose format is based on the constraints of molecules and molecular orbitals. Is it possible that this organic object- the brain- is capable of  a broad enough spectrum of perception that it can understand its place in the universe?

I too am tempted to eff the ineffable. Like my philosophical predecessors, I want to describe that world beyond the window, even though I know that it cannot be described but only revealed. I am not alone in thinking that world to be real and important. But there are many who dismiss it as an unscientific fiction. And people of this scientistic cast of mind are disagreeable to me. Their nerdish conviction that facts alone can signify, and that the “transcendental” and the eternal are nothing but words, mark them out as incomplete. There is an aspect of the human condition that is denied to them. –Roger Scruton

Scientists are reductionists by nature. Scientists naturally seek an irreducible representation of a phenomenon and attempt to describe it symbolically. The symbols may be words or mathematical constructs (what ever it takes to get through peer review).

I think where scientists are not so welcome is in the aesthetic domain of the human experience.  Perhaps our place in the universe is simply to be the conduit through which the broader universe is self-aware. We sentient beings should enjoy that role and have some fun with it.

The Illuminating History of Rare Earth Element Technology

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Until the invention of the electric lamp, the illumination of living and working space was very much the result of sunlight or of combustion.  Since the development of fire making skills in prehistoric times, the combustion of plant matter, fossil fuels, or animal fat was the only source of lighting available to those who wanted to illuminate the dark spaces in their lives.

From ancient times people had to rely on flames to throw heat and an agreeable yellowish light over reasonable distances. A good deal of technology evolved here and there to optimally capture the heat of combustion to do useful work (stoves, furnaces, and boilers) from readily available fuels.

Lighting technology also evolved to maximally produce illumination from flame.  High energy density fuels that offered a measure of convenience for lamp users evolved as well. Liquid fuels like vegetable oils, various nut oils, whale oil and kerosene could flow to the site of combustion and were in some measure controllable for variable output. The simple wick is just such a “conveyance and metering device” for the control of a lamp flame. Liquid fuels flow along the length of a wick by capillary action to a combustion zone whose size was variable by simple manipulation of the exposed wick surface area.

The first reported claim of the destructive distillation of coal was in 1726 by Dr Stephen Hales in England. Hales records that a substantial quantity of “air” was obtained from the distillation of Newcastle coal. It is possible that condensable components were generated, but Hales did not make arrangements to collect them.  Sixty years earlier an account of a coal mine fire from flammable coal gases (firedamp) highlighted the dangerous association of coal with volatiles. So, flammable “air’ was associated with coal for some time.

By 1826 a few chemists and engineers were examining the use of combustible gases for illumination. The historical record reveals two types of flammable gas that were derived from coal- coal gas and water-gas. Both gases came from the heating of coal, but under different conditions. Coal gas was the result of high temperature treatment of coal in reducing conditions. It is a form of destructive distillation where available volatiles are released.  Depending on the temperature, there was the possibility of pyrolytic cracking of heavies to lights as well.

Water-gas was the result of the contact of steam with red hot coal or coke. The water dissociates into H2 and CO. Water gas is a mixture of hydrogen and carbon monoxide, both of which are combustible. The formation of water-gas is reported to have been discovered by Felice Fontana in 1780.

One of the properties of burning coal gas or water-gas was the notably meager output of light from the flame. Workers like Michael Faraday and others noted that these new coal derived gases provided feeble illumination, but if other carbonaceous materials could be entrained, then a brighter flame could result. It was during the course of investigations on illumination with carburized water-gas that Faraday discovered bicarburet of hydrogen, or benzene.

About this time, an engineer named Donovan also noted that if other carbonaceous materials were to be entrained into water-gas, then the light output was enhanced. So, in 1830, engineer Donovan installed a “carburetted” water-gas lighting system for a short run in Dublin.

Coal gas was first exploited for lighting by the Scottish engineer William Murdoch.  Murdoch began his experiments in 1792 while working for Watt and Boulton in England. By the late 1790’s, Murdoch was commercially producing coal gas lighting systems. His home was the first to be lit with coal gas.

The carburization of water gas eventually became an established industry in America in the second half of the 19th century. The treatment of gases, especially with the discovery of natural gas in Ohio, increased the commercial viability of lighting with gas. Carburization of water gas was aided by the discovery of hydrocarbon cracking to afford light components that could be used for this purpose.

Here is where the subject of this post comes in. Since thorium is frequently associated with rare earth elements (REE)  the connection of REE’s to the issue of illumination begins in the laboratories of Berzelius in about 1825. Berzelius had observed that when thoria and zirconia were heated in non-luminous flames, the metal oxides glowed intensely.  But this was not a new phenomenon. Substances like lime, magnesia, alumina, and zinc oxide were known to produce a similar effect. Goldsworthy Gurney had developed the mechanism of the Limelight a few years before. In the limelight, a hydrogen-oxygen flame played on a piece of lime (calcium oxide) to produce a brilliant white glow.  This effect was soon developed by Drummond to produce a working lamp for surveying.

The work of Berzelius was an important step in the development of enhanced flame illumination. He had extended the range of known incandescent oxides to include those that would eventually form the basis of the incandescent mantle industry.  Thoria (mp 3300 C) and zirconia (mp 2715 C) are refractory metal oxides that retain mechanical integrity at very high temperature. This is a key attribute for commercial feasibility.

Numerous forms of incandescent illumination enhancements were tried in the middle 19th century. Platinum wire had the property of glowing intensely in non-luminous flames. But platinum was not robust enough for extended use and was quite rare and consequently very expensive. By 1885, a PhD chemist named Carl Auer von Welsbach patented an incandescent mantle which was to take the gas light industry to a new level of performance. Welsbach studied under professor Robert Bunsen at the University of Heidelberg.

Welsbach fashioned the incandescent mantle into the form that is familiar to anyone today who has used a Coleman lantern. The original mantle was comprised of a small cellulose nitrate bag that had been impregnated with magnesium oxide, lanthanum oxide, and yttrium oxide in the ratio of 60:20:20.  The mantle gave off a greenish light and was not very popular.

By 1890, Welsbach produced an improved incandescent mantle containing thoria and ceria in a ratio of 99:1. This mantle emitted a much whiter light and was very successful. Many combinations of zirconia, thoria, and REE metal oxides were tried owing to their refractory nature, but the combination of thoria-ceria at the ratio of 99:1 was enduring.

Welsbach made another contribution to the commercialization of REEs. Welsbach had experimented with mischmetal and was interested in its pyrophoric nature. He had determined that a mixture of mischmetal and iron, called ferrocerium, when struck or pulled across a rough surface, afforded sparks. In 1903 Welsbach patented what we now call the flint.  In 1907 he founded Treibacher Chemische Werke GesmbH. Today Treibacher is one of the leading REE suppliers in the world.

See the earlier post on REE’s.

REE’s in Greenland.

REE Bubble?

REE’s in Defense.

REE’s at Duke.

Heck and Grubbs

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Richard Heck and Bob Grubbs, Gordon Conference, Salve Regina, 2005

Here is a picture I took of Richard Heck in the spring of 2005 posing with Bob Grubbs before his trip to Sweden. This was taken at the Organometallic Chemistry section of the Gordon Conference at Salve Regina in 2005.  It is a great place to spend a few days giving or listening to chemistry talks, though the dorm accommodations are a bit spartan.

I think the 2010 Nobel Prize in Chemistry for Heck, Suzuki, and Negishi was well deserved.  The coupling reactions they uncovered are a great alternative to some otherwise awkward transformations and have enabled much development around the world.

Here is my question- Is -B(OH)2 a meta or an ortho-para director for electrophilic aromatic substitution? At least in principle. In practice it is difficult to determine due to competing deborylation.

This was taken on one of my very last rolls of Kodacolor film.

2010 Nobel Prize in Chemistry

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10/5/10.  Which chemists do you suppose will get the call from Sweden this year? 

I’ll guess Breslow or Whitesides again.

But then, what about some catalyst guys? Heck, Tsuji, Suzuki, Sonogashira, to name a few? (D’oh!! Are they all alive?)  Think about how normal it has become to do an aryl coupling reaction with a boronic acid and a PGM or Ni.  Look at the wide variety of boronates on the market as well as the endless array of catalysts and ligands for coupling transformations.  

This is what happens to industrial chemists mid-career. We lose track of what is hot in the field as a whole. We’re burrowed deep into the hide of one kind of proprietary technology or other and locked into place by the golden shackles of confidentiality. Pretty soon there are entire fields of endeavor that you’ve never heard of and thirty year old rock star professors who sport big grants and hoards of enthusiastic young acolytes.

Extractive metallurgy of the 19th century

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The first gold lode discovered in Colorado was found where the town of Gold Hill, Colorado, now sits. Gold Hill is presently at the locus of the Four-Mile Canyon fire west of Boulder. As of  today, more than 170 structures have burned, including a few outhouses.

Today, a single gold mining operation remains active at Gold Hill. The kid and I recently visited the area and I wrote a post about Wall Street, south of Gold Hill.

In the last few years I have been fascinated by what started as a simple question-  How did they get the gold out of the ore in the 19th century?  What has become apparent to me as a chemist is the extent to which reasonably sophisticated multistep extraction schemes were employed by 19th century mills and smelters. Their methods of processing would not be unfamiliar to alchemists who practiced similar arts over 400 years earlier.

The alchemists had techniques of calcination, comminution, lixiviation, and distillation available to them. In using these processes, they were inadvertantly performing reduction and oxidation reactions so as to alter the composition of substances with the hope of improving the prospects for isolation of desirable metals.  The 19th century gold and silver mill operators inherited these techniques and mechanized them. One of the key improvements over their medieval predecessors was that they had reasonably sensitive analytical methods as well as some scientific knowledge of the chemical behavior of materials- we call it chemistry today. As the 19th century American gold rush went forward, there became available new methods of gold and silver extraction involving mercury, chlorine, cyanide, and sodium or potassium sulfide and thiosufate.

Any 21st century chemist will recognize most of the inorganic chemistry of 19th century milling and smelting of metals.  But in those days it was not referred to as chemistry- it was known then as it is today as Extractive Metallurgy.

Much of the technology for extractive metallurgy traces back through European mining engineers who had come to the American gold and silver districts.  Two mining engineers in particular stand out in 19th century Au/Ag metallurgy- Guido Kustel and Philip Argall. More about these fellows at a later date. Suffice it to say that they were prolific problem solvers in a time when mine and mill operators typically had more investor’s money than sense.

Some Milling and Smelting Business Models

Prospectors working alone or with investors backing them would prospect a promising area of ground for gold or silver, looking especially for vein outcroppings. If they has cause for optimism they would file one or more claims for the right to have access to the minerals therein. A patented claim was a claim issued by the federal government as a deed that could be bought or old like a a parcel of land. Most of the land of interest was state or territorial land. Many times a claim was filed based on speculation, and a nearby claim with a vein that might go in the right direction would potentially be valuable.

The miners would begin to develop the claim by digging an adit and drifting horizontally following a vein system, or they might dig a shaft in a promising spot in hopes of intercepting a vein rich in value.  Since they were focused on veins which were visible to the miners, the miners were able to dig along the direction of the vein. In doing so, they could hand sort unproductive rock into a waste pile and collect concentrated ore separately.  But then what?

Some mine operators were wealthy enough to have their own mill or smelter to extract the value. However, the majority of mines would sell their ore to a mill, which might be many miles away. A price based on an assay could be negotiated, and the ore sold outright to the mill. The mill would make its profits by selling the gold or silver it extracted. Sometimes a mine would pay the mill a tolling charge and keep ownership of the gold or silver.

Milling and smelting could be a lucrative business or it could result in a total loss. Mills and smelters were run by companies who had plowed a significant financial investment into+ the operation. They relied on the productivity of the gold or silver district. Not infrequently multiple mills or smelters would appear in a district affording lots of competition for ore.   Milling and smelting was labor and energy intensive. Old photographs often show the mills sitting in a mountainous area clear-cut of trees. Wood was needed for buildings and firewood. Refining operations required many cords of wood to run the furnaces or to generate steam for the stamp mills.  If a mill ran out of fuel, their operations were threatened.

Many mines produced ore that was sold to the mill. Mine operators might be paid for the assayed value per ton of ore delivered, or they might be paid a fraction of what was extracted by the mill. The mill could be just down the hill from the adit or shaft, or it might be many miles away.  As a rule, transportation costs were quite high.  Some districts like Caribou had teamsters who would haul ore by horse drawn wagons to mills some distance away. Other districts had rail transportation.

Naturally, ore samples could be tampered with by miners interested in increasing the apparent value of their ore. Sampling methods were developed to produce representative samples for assay. Mills had assay offices to test for the value in the ore and to measure the fineness of their bullion.  Cuppelation was a standard method of providing a gravimetric determination of the gold content of ore.  More on cuppelation in a later post.

The American gold rush and relativistic electrons

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Exactly why do people value gold? Is all of the allure of gold due to its color? What if gold metal did not have the golden color? Instead, what if it had a silver luster like its neighbors on the periodic table of elements? Would we find it quite so appealing?

There are many reasons why people might desire gold.  The motivation to possess gold would surely vary based upon where in the value chain the metal was encountered.  Gold prospectors might value gold because it was an item of trade. Artisans would value gold for more pragmatic reasons relating workability.  Rulers would value gold because it was an asset that could be put in the treasury and later used to buy influence or fund military adventures. Thieves and plunderers valued gold owing its high value per unit volume  and the ability to offer it in trade virtually anywhere.  

Here is what we can say for sure about gold.  It’s high degree of inertness means that it can retain its golden luster indefinitely and bestow an everlasting aspect. Its malleability and ductility means that metalsmithing with fairly primitive tools was feasible. Gold could be hammered into thin sheets that could be cut, punctured, and otherwise worked by artisans to produce impressive art objects. Gold could be worked to produce all manner of ornamentation for the sake of religiosity, as an ostentatious display of wealth and power, or for coinage. Whatever the context, gold leaves an impression on people, aesthetic or otherwise.

Here is where it all gets interesting. You see, one of the consequences of Einstein’s theory of relativity is that as an object approaches the speed of light, c, its mass increases by an amount defined by a fairly simple mathematical relationship. An object’s rest mass is less than its mass appreciably near lightspeed.  The term “relativistic” refers to effects relating to objects traveling near lightspeed.

It turns out that some of the outer electrons around heavy atoms like gold and mercury are moving at an appreciable fraction of the speed of light- they are relativistic electrons.  If these relativistic electrons are at the outer, valence level, then aspects or behaviors affected by relativity may become apparent by how the atom interacts with light or other atoms. 

Chemistry is about the behavior of electrons confined to the space in the immediate vicinity of nuclei, or bound electrons. In particular, the electrons outer, valence, electrons. This is the realm of chemistry.  Chemists go about their business manipulating these electrons for fun and profit. Virtually our entire material experience of life is dictated by the manner in which these electrons interact.

In the case of gold, the 6s electrons are moving at a significant fraction of the speed of light. The magnitude is 58 % of c, according to one internet reference. At this velocity, the electron mass has increased by a factor of 1.22 times its rest mass. This being the case, the Bohr radius of the orbital is contracted by 22 %. 

The implication of this perturbation in orbital size is that an electronic transition between the 5d and 6s orbitals shifts out of the UV range and into the visible band. The molar extinction from the UV cutoff to about 500 nm is high enough that metallic gold takes on its characteristic golden hue from the reflected light.

Gold is not the only element to be affected at the valence level by relativistic effects. Mercury is also affected. The contraction of the 6s orbital results in relative inertness of the 6s^2 lone pair and poor interatomic (metallic) bonding, resulting in the unusually low melting point of mercury.  Indeed it is likely that most of the interatomic attraction is due to van der Waals forces, which is notably weak.

The inertness of the 6s lone pair reveals itself in the oxidation states of bismuth, which has stable oxidation states at +3 and +5. Like other pnictogens, bismuth (III) compounds have a lone pair. But unlike nitrogen and phosphorus lone pairs which are reactive and an important part of their ordinary chemistry, bismuth’s 6s lone pair is rather inert and not significantly hybridized. Triarylbismuth (III) compounds are trigonal planar with the lone pair taking spherical s-orbital symmetry.  UV-Vis experiments will show that for some simple BiAr3 compounds, the n->pi* transition has a very low extinction coefficient, unlike the analogous Ph3P.  Exposure to Pd(II), for instance, will show scant indication of coordination in the UV spectrum, again unlike Ph3P.

This is quantum chemistry stuff that the reader can run down later. What is of interest to me in this post is the fact that, without knowing it, gold prospectors, miners, and mill operators of the 19th century took full advantage of certain relativistic effects in their search for gold.

The first relativistic effect the early miners took advantage of was the simple fact that gold is a colored and relatively inert metal. It could be spotted by simple inspection in streams and quartz veins. The color of gold made it impossible to confuse with other metals. Ofcourse, iron pyrite was always a problem, but there were simple ways to test for pyrite.

The other relativistic tool used by miners was amalgamation of gold (and silver). Mercury, being a metallic liquid by virtue of relativistic valence electrons, could be intimately contacted with gold dust or larger particles to form a solution that would remain liquid up to some modest fraction of gold. Mercury, being quite dense, would naturally seek the low points where the gold would also be found. This dissolution could be affected by simple sloshing or by grinding the mercury with the ore in an arrastra or an amalgamation pan.  After agitation, the mercury would pool and could be easily collected.

Later amalgamation techniques would combine aqueous cyanidation of the ore in the presence of mercury in hopes of better gold and silver  recovery. Reduction of gold or silver chloride occured in-situ to provide amalgam.  Amalgamation of ore that had been chlorinated by roasting in the presence of NaCl was a common solution to the serious problem of sulphuretted auriferous or argentiferous ore.

The miners of the 19th century American gold rush certainly didn’t know that their task of extracting gold would be aided by the effects of high velocity electrons. Most people walking around today don’t know or even care about this more than 55 years after the passing of Albert Einstein.  But it goes to show how subtle effects of nature can affect our lives in unexpected ways. And this is just one of many such nuances of physics.

Cogitations on the sunflower

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My morning commute through the countryside takes me past more than a few fields of sunflowers. By late July the flowers are out and without exception, all nodding toward the east where a star appears every day. Many of the local farmers have taken to raising sunflowers rather than the usual corn and sugar beets.  I haven’t a clue as to what kind of machinery is used to harvest these things.

One of the local heliotropes

It is uncanny that the entire crop will lock the flowering body orientation in the direction of the sun.  Somehow the direction of the sun at other times of day does not randomize the orientations. If you stand and look at a field of sunflowers, you’ll see outliers in height, but not direction of flower orientation. Or so my experience has been. There has to be some frequency of orientation outliers.

I wonder if there isn’t some growth step in the stem than occurs over a short time span X days into its growth, removing what stem mobility that might exist and locking the flower in place?

Such things make me wonder if our concepts of consciousness, with human consciousness as the benchmark, aren’t a bit too self serving.

Process development and struggle

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One of the hazards of having a degree in chemistry is the appealing idea that you can explain everything and predict everything on the basis of textbook notions on solubility, electronegativity, pKa’s, or molecular orbitals. These are important things to be sure. But in the field, the recall of knowledge isn’t always enough. More often than not you have to collect data and generate new knowledge.

Rationale of a result on the basis of hand waving and a few reference points can seem compelling in a meeting or brainstorming with a colleague to understand a problem. But in the end, nothing can top having solid data from well conceived experiments.

My chemical “intuition” have proven wrong enough times now that I am deeply skeptical of it. After prolonged periods of absence from the lab I find myself resorting to a few cherished rules of thumb in trying to predict the outcome or explain the off-normal result of a process.

In chemical process development there is no substitute for running experiments under well controlled conditions and capturing solid results from trustworthy analytical methods. It is hard work. You may have to prepare calibration standards for chromatographic methods rather than the preferred single-transient nmr spectrum  in deuterochloroform.

We’re all tempted to do the convincing quick and dirty single experiment to finesse the endpoint. Certainly time constraints in the manufacturing environnment produce an inexorable tilt towards shortcuts. But in the end, depth of knowledge is only had by hard work and lots of struggle in the lab. The most important part of science seems to be to frame the most insightful questions.The best questions lead to the best experimental results.

NatGeo King Tut Exhibit- Ho Humtep of the Ballyhoo Dynasty

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Th’ Gaussling went on a minor field trip recently to the local art museum in Denvertown to see the marvels of King Tut. And what a marvel it was … of marketing. It is hard to say that the exhibit met expectations. To be sure, there are some fine artifacts on display.  And it is a splendid example of museum-craft. Notable is the exquisite goldsmithing and scuplture on display. There are decorative articles that resemble a form of gold filigree that are quite impressive for the era. My northern European ancestors were sleeping in hollow logs and howeling at the moon when the Egyptians were doing the work on display.

But at the end of the day, the exhibit is yet another recasting of history in a theatrical form suitable for the attention deficit masses. Case in point:  a video short subject portrays DNA work on a mummy where the scientist assures us that such research is a part of the larger effort to cure disease.  Golly, sounds urgent.

Well, maybe there will be useful findings that contribute to the betterment of human health. But if it doesn’t , is the knowledge useless? I think not. This is the same sort of lame apologia used for jusifying space exploration or studying the frogs of Amazonia. If you are not looking around, you are not going to find new things.

Scientists should stand firm with the conviction that exploration is a net benefit for mankind. We should be more careful that claims of a breakthrough are tempered bya realistic warning about the speed of progress.  We should stop leading people along with false expectations about the fabulous things just around the corner. All progress is the result of prolonged hard work by many people.

Travel Tips From the Department of Devil’s Advocacy

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If you’re wandering the country on I-90, say to or from Sturgis, SD, a stop at the Devil’s Tower north of Sundance, WY, is very worthwhile.

Devils Tower

The identity of this geological oddity is the subject of some disagreement. Three theories of its origin are in play: 1) an igneous stock, 2) a volcanic neck, and 3) the remnants of a laccolith. Whatever the case, it is plain that the sedimentary rock surrounding it has long since eroded away to reveal the more weather resistant igneous rock. 

Climber on Devils Tower

Close up, the columnar structure of the formation is evident. This feature speaks to a slow cooling process, one made possible for a magmatic body deep underground insulated by the surrounding formation.

Devils Tower, Wyoming, June 2010.