Category Archives: CounterCurrent

On the manufacture of hazardous materials

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How does one decide if a given compound is too hazardous to manufacture at a particular site? The answer to this question is much harder to arrive at than you might imagine.  It is very easy to spout glib, hand waving statements about risk analysis and risk based process safety. It is quite another matter to actually conceive of experiments to tease out the safety data and compile it into knowledge based practice.  For the manufacturer there are two kinds of operating hazards to contend with- 1) physical hazards, and 2) regulatory hazards.  Getting into trouble with either can bring your operation to a halt.

In general, there are two kinds of GO / NO GO approaches to the question of going forward with any given material. One method applies some kind of quantitative risk analysis based on accumulated knowledge combined with hazard thresholds defining acceptable risk. Regulatory compliance and insurance issues may apply, or not.

The other general approach is simply a management decision. The board of directors or CEO decrees that we’ll go forward and do what it takes to operate safely. Or management decrees that we will not go forward with the manufacture. We’ll let someone else have that plum.

I recall being at a propellants conference a few years ago where a representative from a solid propellants manufacturer asked me if we would consider making lead styphnate. I paused for a moment, as if to be carefully weighing my answer, and replied with a flat ‘no’.  The fellow wasn’t surprised and went on his merry way. This was the exercise of an informal method of process safety. Decline to make the obviously hazardous materials.

The threshold for the definition of hazardous materials varies considerably within industries and between them. The spread of hazard types across the manufacturing world is large and perhaps confusing.  Two of the broad types of manufacturing hazards are hazardous energy and toxicity.  Hazardous energy is found in operations with high pressure, flammable materials, mechanical energy, chemical reactivity, electrical energy, and explosive materials which is a combination of chemical reactivity and mechanical energy.

Toxicity

Toxic hazards are a group that cover a wide range of physiological effects and modes of dosing. Toxicity issues relating to manufacture can be a very complex matter and it is best to involve experienced hands to sort out the good sense fom the nonsense. To a large extent, the maufacture of toxic materials is covered by the proper application of personal protection equipment (PPE), good plant hygiene, and a process that keeps toxic materials contained to the greatest extent possible. The pharma people know all about this activity. But in the specialty chemicals business, a good deal of the chemical intermediates that go out the door have poorly understood toxicology.  

Products that are made for dispersal into the environment are subject to much greater oversight by EPA. But the same is not true for a great many chemical intermediates. Chemical intermediates flow through different  regulatory pipelines with some under thorough regulatory scrutiny and others considerably less so. Pharmaceutical intermediates may or may not be covered under FDA GMP rules. Very early intermediates may be items of commerce and not subject to the Byzantine ways of GMP. Later intermediates may have FDA requirements that handcuff you to the bedpost.  It is possible to have a very prosperous career outside of the GMP world.

Chemicals that are not for pharmaceutical or pesticide use may be listed under TSCA.  Chemical Abstracts Service maintains the list and access to entries is had through the CASRN, or the CAS registry number. TSCA is a type of oversight promulgated by the EPA and is intended to provide scrutiny in regard to worker exposure and environmental release during the execution of a chemical process. EPA does consider the toxicology and environmental  literature and is able to model the fate of a release into the air or water by calculation.

While specialty chemicals are subject to TSCA regulations and an approval by EPA, only cursory toxicological examination is customarily performed. TSCA approval is either in the form of a listing or through a low volume exemption. PSM regulations promulgated by OSHA provide regulatory crossfire on the manufacturer in that OSHA regulations require enough safety testing as to provide a safe working environment.  So together, OSHA and EPA cover a great deal of area in manufacturing safety. The rules are meant to be proactive, but they also provide substantial penalties for infractions. There is much more depth to TSCA and PSM than I have mentioned here, obviously. It is important to have people on staff who specialize in regulatory affairs.

Testing for toxicological effects is time and resource consuming. Much planning must go into such testing and it must be started well in advance of plant operations. Substances that pose a potential risk to workers via chronic occupational exposure during manufacture and handling are good candidates for such testing. However, if the substance is not a commodity chemical and if the substance is made only during infrequent campaigns for a limited group of users, it is less than likely that it will have been tested.  The best approach to manufacturing a substance with little data available on toxicity is through the use of precautionary guidelines with layers of protection for the operators. That is, design a process that prevents exposure of the workers to the product and offers redundancy in engineering and administrative controls. The coverage must include production operators, maintenance crews, warehouse workers, chemists, and engineers.

Hazardous Energy

Reactive hazards and hazardous energy issues can and should be investigated by the manufacturer to the greatest extent possible. While such activity can be farmed out to commercial labs, it is very important for management to grasp the benefis of in-house expertise.  Depth of knowledge is important in understanding and preventing  upset conditions. But the accumulation of such depth of knowledge is expensive and subject to throttling by management. It always involves accruing more information than is apparently needed, at least initially.

Science is to a large extent about understanding boundary conditions. In the same way, chemical safety requires understanding the conditions for the release of hazardous energy, decomposition, or other undesirable attributes.  What you’ll find quite often is that a single measurable attribute is not enough to assemble a complete picture of reactive hazards. Most reactive hazards are understood by assemblig a composite of several kinds of experimental results for a more complete appreciation of the dimensions of the reactivity.

To find such boundary conditions one needs to conceive of experiments to tease out the effects. Some kinds of information relating to safety issues can be obtained by instrumentation. Differential Scanning Calorimetry (DSC) is one such technique that gives a quantitative picture of the heat evolution of a substance while it is being heated over a planned temperature range. Thermogravimetric Analysis (TGA) of a test substance gives an indication of mass loss as a function of temperature. Accelerating Rate Calorimetry (ARC) shows heat flows into or out of a sample while recording sample cell pressure.  ARC goes a bit further than DSC in that the evolution of non-condensable gases can be inferred by the shape of a derived Anton curve. ARC also gives an indication of time to maximum rate (TMR), which is a useful parameter in determining the maximum temperature or residence time for a reactive material or mixture. Reaction Calorimetry (RC1)  shows the heat flux profile of an actual reaction mixture over the course of reagnt dosing. RC1 may be used to look for the accumulation of energy in a reactor. There are other tests available, but I cannot attest to them on the basis of personal experience.

Explosivity

Noninstrumental methods of safety appraisal include the tests for explosive properties. There are well defined protocols for explosive testing and they are applied in layers. It is very important for people handling new materials that may have explosive properties to understand the various assays for explosivity. 

Explosivity (or explosability) may be manifested in many ways and there are tests to tease out sensitivity to a measured stimulus. The key point I’m trying to make is that explosivity is a composite property sensitive to multiple kinds of stimulus and physical circumstances. Many materials are explosive only according to a few kinds of tests.

Safety testing for materials that may be energetic include BOM (Bureau of Mines) or BAM fall hammer tests and the BAM friction test. These tests do as the names suggest- look for thresholds for sensitivity to impact or friction.

The Koenen test  looks for explosivity when a material is heated under partial confinement, i.e., material is packed in a metal tube with a small hole in the end. Materials that are merely flammable will decompose and vent through the orifice. Compounds that are explosive may cause the Koenen tube to burst.

The time/pressure test is used in DOT classification and consists of a pressure vessel fitted with nichrome wire and a pressure sensor. The sample is heated with the nichrome wire or flame and the pressure is monitored. A pressure rise from 100 to 300 psi in 30 msec or less is regarded as having rapid deflagration properties and an qualifies as a positive indication for explosivity for transportation purposes. For the process chemical industry, this test gives an indication of the potential for rapid gas formation and the unwanted PV work it may do on your equipment.

There is a  series of tests used for DOT classification of explosive properties that will give useful insight for those who propose to manufacture intended or unintended energetic materials. It is useful to have material tested to assemble the composite picture of the materials sensitivity.  Questions to ask are: 1) does the material show any positive indications at all? 2) If explosive indications are found, is confinement required? 3)  Does the material show any detonability at all? 4) Can you fnd any sensitizers or catalysts to explosivity? 5) Does the material transition from deflagration to detonation? 6)  Is the material sensitive to stimulus by electrostatic discharge (ESD)? 7) What temperature gives a time to maximum rate (TMR) of 24 hours? 8) Do the decomposition products contain non-condensable gases?   There are more questions to ask. Remember not to confuse detonation with explosion.

For the chemist interested in manufacturing a product that has known reactive hazards associated with it, it is useful to have collated the data. The application of knowledge of reactive hazards depends greatly on the kind of equipment to be used and the kind of chemistry to be performed. It is possible nonetheless to make a few useful generalizations.

Accumulation of Hazardous Energy

The execution of a chemical process usually requires that two or more substances be put into physical contact in a solvent. This is a point at which hazardous energy may be evolved. Obviously, for promptly reacting systems the rate of heat generation must be less than the rate of heat removal to avoid a runaway situation. But special care must be taken for reactions that are not prompt and that might allow for the accumulation of unreacted material in the vessel. This unreacted material in a reation vessel represents an accumulation of potentially hazardous energy. Good process R&D will identify reactions with latent periods or reactions that are particularly slow to start. Problematic reactions require good in-process checks to ascertain the state of the rection. Very often, a heat kick is all you need to see to know the reatcion has begun.

Grignard reagent reactions are notorious for being slow to start, tempting operators to “goose” the reaction by adding more RX to the pot. Above about 10 % of RX over Mg, the potential for a runaway initiation is very high.  It is best to limit RX addition to a maximum of 5 %. If no initiation is observed after a reasonable attempt, the chemist must be awakened and hauled to the plant to provide on the spot guidance. Generally, initiation is a matter of time. But but sometimes parlor tricks must be used to activate the Mg. These are well known. It is always best to use these activation tricks prior to addition RX to the pot because otherwise a rapid consumption of RX may occur.

Solids Handling

It is always more desirable to handle sensitive or reactive materials in solution. They can be piped around under inert atmosphere and generally protected from environmental problems. However, sometimes there is no way to avoid the handling of reactive solids. That is, solids that are sensitive to O2 and/or water. The sensitivity may only go as far as quality control and specification problems. Or reactive hazards may be in play.

Solids handling is problematic in certain operations. Charging a reactor with reactive solids requires specialized solids handling equipment. Even non-reactive solids present a problem in handling. Dumping solids into an open manway can result inan  incendive electrostatic disharge. It’s made more serious if there is a flammable solvent in the vessel. Here is th rule- you don’t add solids into a reactor manway of there is the possibility of explosive dusts or flammable solvent in the pot.

Filtration is another problematic operation. Well, let’s say that opening the filter with reactive materials in it is a problem. If you use BuLi orRMgX, you probably have to do a  filtration at some point. Unless you quench the BuLi or RMgX in the pot, you are likely to have a hot filter cake.  While I cannot divulge any particular methods here, I can say that managers have to address this issue one way or another. It is especially exciting if the hot cake is wet with a flammable solvent. So, ESD and other ignition sources must be delt with when the filter is opened. Operators must be grounded and all locations for possible charge isolation must be accounted for.  It is best to open a filter in a location where having a hot cake fire is acceptable.

Filter cakes may be waste or product, depending on the circumstance. Drying operations in the filter must account for the accumulation of electrostatic energy as the material dries. It is important to have decay times for the solids if they are potentially energetic. Energetic materials that accumulate static must be allowed to decay their charge prior to handling. Of course, the prevention of charge accumulation is best. Propellant folks will coat granulated or pelletized product with charcoal or grapite to render the solids conductive.

Packaging

Chemists really hate to have to worry about packaging, but I can attest this is an activity that attracts quality control problems. Obviously reactive materials must be compatible with the  package materials of construction. Containers must seal properly.  Steel drums are useful for many kinds of materials, but the bungs can and do leak with temperature changes, so they can pull in moist air.  In terms of reactive hazards associated with containment, usually some choices have to be made. What kind of leak scenario is plausible and does the proposed container pose any special weaknesses? Drums are notoriously susceptable to being speared by forklifts. Cylinders too. 

What hazards are present for a workman who opens the drum with the hazardous material? Does the operator have to open the drum and put in a dip tube for pumping out the material? Perhaps a cylinder with a built in dip tube is safer.

Another matter to consider, especially with solids, is the issue of static charge generation during filling operations. Is the container or liner  conductive or dissapative? Are ESD procedures in place for safe handling?  Liquids can generate considerable static energy, especially when low dielectric constant liquids travel through a plastic pipe.  Transfer of flammable organic fluids should take place in grounded or bonded conductive pipe to the greatest extent possible to avoid charge isolation.

All equipment should be grounded or bonded via a ground that is periodically tested for integrity. Everything should be at the same potential as the ground.  Cement floors are dissipative, but painted cement floors are not. Wooden pallets and fibreboard packaging are dissipative when sitting on bare concrete.

Wherein Th’ Gaussling presumes to take exception

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Some matters to which I wish to take exception.

Cray, the supercomputer company, is selling a desktop unit called the CX1. Their product literature uses the term “personal supercomputing” here and there. Also HPC, high performance computing.  A bit of scouting with Mr Google turns up a price of $25,000 (and up) for one of these units. If I had a CX1 I could finally get those hydrodynamic simulations finished for my cold fusion reactor.

I’ve never been able to refer to a computer as a machine. It’s a circuit. Somehow the flow of a few coulombs of charge across the bandgap and through the microscopic vias of lithographed and ion implanted junctions never qualified in my internal taxonomy as a machine.  Surely there are countless pencil necks and Poindexters out there who will line up to quibble. But, it’s a damned circuit. The cooling fan is a machine. The screws that hold the major components are elementary machines. The Klikkenhooters on the mouse are machine-like I suppose.

My eyes cross every time I hear some silly sod in the IT department solemnly state that they have fixed a problem in some persons “machine”.  Oh, is that true skippy? Chances are that young Edison selected a pull down menu and changed the state of some software variable or swapped out an errant disk drive. Machines make you greasy. You skin your knuckles tightening bolts on them. A Harley-Davidson motorcycle is a machine. A Dell laptop is not.

Fiat Lux

On an altogether different topic, an article entitled the Amoral Manifesto over at Philosophy Now raises some interesting issues regarding the basis of morality. The author is starting to get his arms around the qestion of morality without an absolute cosmic foundation. If you look at the physical universe, one of the first things that sorta jumps out at ya is the fact that everything is floating in space. Maybe we should take that as a kind of metaphor when considering absolutisms. We should learn to get along for its own sake, and not just to please angry, dispeptic spirits.  Not that those jabbering snake handling pentecostals would take any notice …

Speaking of dispeptic, Pastor Wingnut in Florida should consider another alternative to book burning. Simply down load copies of the Quran and repeatedly delete them until he feels that warm flush of righteous satisfaction.*  But I think we all know this wouldn’t have quite the spectacle of an actual public immolation. A book burning isn’t about individual books. It is a form of ceremony.  It is a ritual for all to particpate in and is part of the liturgy of indignation. Producing a show like this is in the skill set of any preacher, actually. They are expected to rouse  the emotions of their flock. It’s their job.  Some of it is quite interesting to watch in terms of the art of persuasion.

The pastor in Florida makes the case for why a great many of us do not want a government based on theological notions of law.  Whose law takes precedence- the Baptists?  Whose voice is speaking to you, really? And did you get all of the details? Exactly what kind of authority does an angry but righteous-in-the-Word mob get to have, anyway? How do bronze-age principles help us determine quotas for banana imports, plumbing codes, and the standards governing interstate trucking? Good gravy, we have to figure these things out ourselves people.

The eternal problem of civilization is to find the balance between high principle and pragmatic practice.  Civilization should be run by the living, not dictated by those who claim to know the intent of the long dead. The dead had their time in the sun. It is the privilege and responsibility of the those living the eternal now to sow the seeds of their fate. Easy retreat to the demon-haunted, authoritarian world of spiritualism is the realm of ignorance and fear. And fearful people are especially prone to being driven like sheep at the convenience of the vain and ruthless. History books are full of examples. So instead of burning the Quran, let’s read a few of the others. Maybe take some notes.

* Thanks to the Daily Kos.

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 secret life of the industrial chemist

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My blogging output volume has dropped to a trickle, and what little of what is posted is just blather.  Despite the relative quiescence of this blog, the blogger himself is busier than a one-legged cat trying to scoot across a frozen pond. Unfortunately, the one-legged cat has to keep mum about the missing legs or why he is on the lake in the first place.  If I don’t stroke out from the chronic cortisol exposure, I’ll write about it all one day.

After some years in the industrial setting I am able to see why there is such a disconnect between academia and industry. The imperatives of the industrial chemist are dramatically different than that for a brother or sister chemist in academia. It is the job of the academic chemist to uncover new phenomena and tell the world about it. Oh yes, and teach a few students along the way.

The industrial chemist’s job is to apply known processes or to uncover them himself for greater profit for the stock holders. The main difference is that the industrial chemist must keep the work secret, or more accurately, out of the public domain.

Why did I use the word ‘disconnect’?  Well, if an industrial chemist wants to collaborate with an academic partner, the matter of secrecy comes up.  If the academic cannot transmute the work into a scholarly publication for inspection by the promotion and tenure committee, then he has effectively been unproductive.  Academics turn funding into publications. Well, except for the 50 % of the money that goes into overhead support.  If an academic does collaborate with an industrial group, there is the very real problem for the academic of how to use the work for career advancement, i.e., publication. Just covering academic labor and materials isn’t really enough (or shouldn’t be) for the university workers.

Another issue arises in regard to intellectual property. That is the matter of secrecy within an academic research group.  Say professor Smith has taken advantage of the Dole-Bayh Act and is performing research with the goal of applying for a patent. This very fact sets the group down a path that requires non-disclosure of results prior to and during the application.   Several things have to be in place in an academic lab that are unusual for the academic setting, but normal for the industrial setting.

First, patent-seeking academics must be very quiet about their work during the critical concept development phases. One of the most disastrous things that can happen to a patent application is confusion relating to the matter of inventorship.  And one way to muddy the inventorship is to be careless about who is involved in technical discussions while the invention is in the formulative phase. In the university setting, group meetings with outsiders or uninvolved group members can lead to unexpected and poorly documented inventive contributions.

Word to the wise: You don’t have to wait for someone to complain about inventorship after the patent is allowed. If your own patent attorney, who is an officer of the court I might add, gets wind that someone was left off the inventors list during prosecution, he/she is duty bound to amend the application, possibly casting doubt in the mind of the examiner on the veracity of earlier signed documents.

Playing games with the list of inventors is the fast track to rejection of the application. All inventors and assignees should clearly understand that your own patent attorney, the one whose boat payment you’re funding, answers to a higher calling, so to speak.  They have obligations and liabilities that you can’t  imagine. Help them get you a patent with the cleanest possible file wrapper.

An academic research group with more members than inventors probably needs to split the invention away from the rest of the group. This is a good opportunity for the patent attorney to school the group members on the patenting process and outline best practices. The research prof should outline a plan to partition the group in a way that disclosure is minimized. Notebooks and meetings should be carefully monitored in any event, but some kind of isolation is always best.

Then the question arises of what to do with thesis work that arose from an incomplete patent project. What does the student get out of it? This is magnified even more if the professor is part of a startup company who intends to use the technology the grad student developed. Again, what does the grad student get of it?  A degree? For development services in getting a startup off the ground?  Good question. Certainly there examples out there where these matters have been worked out.

My views on academic patenting have been expressed previously and I still believe it is terrible public policy.

It is plain that patenting in the academic environment poses special challenges and cultural changes for those hoping to get a patent.  In the industrial setting, such matters are normal and institutionalized.

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.

Some Questions

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What do farmers think of crop circles? Isn’t it just … vandalism? Is there such a thing as crop circle insurance?

Many of the fellows who boarded the three ships at Griffins Wharf and pulled off the Boston Tea Party were disguised as Mohawk Indians. How patriotic or heroic is it to destroy property and attempt to blame others for the deed?

When Rand Paul implodes alone in the forest, will he make a sound?

An involuntary grunting reflex

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Make magazine is one of my very favorite publications. It’s made for hillbilly engineers and aspirants like myself.  Their Maker Shed Store offers kits as well as plans for making all sorts of cool gadgets. Check out this Berliner Gramophone kit and this vacuum tube radio kit.  

Kit building and garage engineering are important activites for aspiring young scientists. We senior scientist types should be on the ready to mentor local high school students in their bid to learn about technology from the ground upwards.

Electronic experience is invaluable to all experimentalists- physicists, chemists, geologists, biologists, etc- and is a subject of lifelong utility. Many students do not have peer groups or family members who can help them get into this subject.

As a junior high school kid, I worked on TV sets (tube electronics) and acquired some electrical and mechanical ability in doing so. I actually fixed a few problems, surprisingly. A family friend had a TV repair shop (remember those?) and as a result I had a steady supply of TV chassis to take apart for my collection of parts like potentiometers and variable capacitors.

Like most kids rippin’ stuff apart and eyeing the construction methods I gained valuable electrical insights and personal experience with electrical current.  Like the time I discharged a picture tube through my hand while trying to remove a flyback transformer from my grandparents color TV. It was great lesson in capacitance and isolated static charge. As my grandparents sat on the Davenport and watched, they heard a sudden and involuntary grunting noise burst from my mouth as I hurled myself from a squatting position by the opened console TV set and backwards across the room. I probably absorbed more joules of energy from landing on my backside than the joules absorbed by my hand. Luckily I was not burned. The next day I learned how to properly discharge the aquadag in the picture tube.

It is nothing at all like tangling with an vicious animal who might stand there after the altercation spent and panting, wondering in its little badger brain how to tear an even bigger chunk out of your leg. A discharged electrical appliance bears the same silent affect before as afterwards. It’s wicked electrons are inanimate and unparticular in their singular drive to find ground. An unexpected jolt from a device is much like a magical experience. It comes from nowhere and everywhere and is over in the blink of an eye. Afterwards you stand there in shock and awe of the effect of even modest amounts of energy.

The impulse to do science is also the impulse to find boundary conditions of phenomena. Where are the edges? How does it switch on or off? You have to be willing to leave some skin in the game to find out about things.

Obstreperous Theocracy

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So it appears that the US is quietly building up military forces within striking distance of Iran. The island of Diego Garcia (UK) has served as a staging area for standoff weapons. The military-political establishment has been busy with threat analysis and is evidently staging forces to some extent based on their conclusions and evolving policy.

I think there are many credible arguments that rightly assert that Iran is an active threat to what passes for stability in that region. Or at least at the first-order level of political analysis. Iran is plainly an obstreperous theocracy with a particular zeal for the export of its orthodoxy.

As always, the drums begin to beat for war and the business of manufacturing public consent begins in earnest. I’ll go out on a limb and make a gross generalization. All human populations seem to have a fraction, say 1/4 , who are particularly fearful by nature. These are the folks who susbscribe to concrete notions of nationalism, righteousness, and the associated keenness for adherence to orthodox doctrine. These were key proclivities of the US/Soviet cold war era. It is part of a collective consciousness that is especially adept at finding patterns that validate its fundamental fear.

It would seem that we may be in yet another run up to the projection of force on the far side of the world. A good question would be this: Are we addressing the fundamental cause of World-vs-Iran conflict? At minimum we trying to shore up the result of a century of bad western foreign policy.  This region is at the overlap of profound social forces associated with abrupt infusions of petrodollars, reflexive militarism, ethnic antipathy, and religious orthodoxy.

I think that Chomsky has some valid points about the origin of these conflicts. Iran and other groups have used the Israeli-Palestinian conflict as a bully pulpit for their own regional ambitions. Obviously there is sincere religious and ethnic outrage over the the Palestinian issue. But a state like Iran is sure to use this conflict to their own political advantage to exercise the projection of power.

The US and other western states have chronically miscalculated the magnitude and direction of regional conflicts.  For instance, would a military strike against Iran be viewed as just an attack on the government of Iran, or as an attack by infidels on Shi ‘ism? Are we prepared for what would follow? I think I can guess the answer.

Andy Grove on Scaleup

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Andrew Grove is the former CEO of Intel who was responsible for its transition from memory chip producer to microprocessor producer. According to Wikipedia, Grove is responsible for an increase of 4500 % in Intel’s market capitalization. In his youth he and his family escaped from Budapest, Hungary during the Soviet invasion of 1956. Groves holds a PhD in chemical engineering from UC Berkeley. Grove is now retired and is a senior advisor to Intel.

Grove recently wrote an article for Bloomberg that is quite insightful in its analysis of certain aspects of American corporate culture. In particular, Grove notes the disconnect between US technology startups and the subsequent expansion of business activity leading to job growth. He also notes that startups are failing to scaleup their business activity in the USA. The Silicon Valley job creation machine is powering down.

Grove makes an interesting point here,

A new industry needs an effective ecosystem in which technology knowhow accumulates, experience builds on experience, and close relationships develop between supplier and customer. The U.S. lost its lead in batteries 30 years ago when it stopped making consumer-electronics devices. Whoever made batteries then gained the exposure and relationships needed to learn to supply batteries for the more demanding laptop PC market, and after that, for the even more demanding automobile market. U.S. companies didn’t participate in the first phase and consequently weren’t in the running for all that followed. I doubt they will ever catch up.  Andrew Groves, 2010, Bloomberg.

To build on what Grove is saying, I’ll embellish a bit and add that an industry is actually a network of manufacturers, suppliers, job shops, labor pools, insurers, bankers, and distributors. When deindustrialization occurs, the network of resources collapses. The middle class takes a big hit when a commodity network moves offshore. In the end, the intended market for commodity goods and services- ie., the middle class- is weakened by the very move that was supposed to keep prices down and profits up.

Grove is most concerned with the matter of scaleup. This is the business growth phase that occurs after the entrepreneurship proves its worth in the marketplace. Investors pour money ino large scale operations and staff to get product onto the market. Grove suggests that investment in domestic startups who do not follow on with domestic scaleup are not participating in keeping the magic alive.

Offshore scaleup negatively counteracts the benefit of domestic innovation. In a sense, it is an abdication of the trust given to the entrepreneurs by the citizens who provided the infrastructure to make the innovation possible.

Grove makes a good point in his editorial and I think that the rest of us need to take an active stance to question the facile analysis so often uttered by business leaders when it comes to relocation of business units offshore.  Citizens paid for the infrastructure and a large part of the education that makes our innovative technology possible. There needs to be more public pushback on business leaders and government officials about this topic.