A Poetic Champion of Chemistry

A Poetic Champion of Chemistrytc "A Poetic Champion of Chemistry"

In all branches of science, a theory that is once found to have any fault whatsoever must be either discarded or sufficiently revamped.  This is also true for hypotheses, which are never intended to be factual statements, but mere starting points. Can the same be said for whatever hypotheses and/or theories are put forward in the arts? For example, Auden’s too often quoted statement, “poetry makes nothing happen”, is wrong, and had in fact been proven wrong in a scientific context about two hundred years before Auden was even born.

The name Darwin is a well known one is science. Almost everyone has heard of Charles Darwin, his voyage on the Beagle, natural selection, The Origin of the Species and so on, but fewer have heard of his grandfather, Erasmus Darwin (1731-1802). The latter was a physician who won great fame with the publication of Zoonomia, a hefty book about medicine and animal life. However, Erasmus Darwin was also a compulsive inventor and a keen experimenter in physical science. His book of poetry, The Botanic Garden, ed by extensive scientific notes, was so successful upon publication that he was generally acclaimed to be the leading English poet of the day.

Scientifically, Darwin was primarily interested in the properties of gases and steam.  A paper on the “ascent of vapours” led to his being elected a fellow of the Royal Society where he helped to advance physics, meteorology and geology. His contributions to chemistry arose through his participation in the “Lunar Society of Birmingham”. This group, which included James Watt and Benjamin Franklin among others, met once a month on the night of the first full moon to discuss science. In 1780, Joseph Priestly came to live in Birmingham and his experiments gave the Lunar Society a new focus.

At that time water was generally regarded as a simple element that could not be decomposed but when Priestly used an electric spark to explode a mixture of hydrogen and air the vessel walls became dewy.  This led to what historians of science have called the “water controversy” which may, in fact, have been set off by Darwin himself in a witty letter to James Watt.  In the ensuing dispute, based upon chauvinism as much as it was on science, Darwin broke camp and tended toward the French side led by Antoine Lavoisier. He did so again later when he spoke against a theory accepted by the English but not the French.

Darwin presented his views in The Botanic Garden where the science at times overwhelms the verse.  He wrote about the marriage of oxygen and hydrogen to form water in a poem footnoted with references to the work of Lavoisier. He employed Lavoisier’s language and thus, his use of ‘oxygene’ (the French spelling) is the first positive use of the word in the English language.  The leading English chemists at that time only spoke of oxygen in negative, anti-French terms.

The first English usage of the words, hydrogen and azote (French for nitrogen), also occurred in The Botanic Garden. Thus, Darwin may be viewed as the verbal father of hydrogen and oxygen.  In another book on plant life, Phytologia, Darwin describes the process of photosynthesis better than anyone before him.  He gives what is essentially a chemical equation in word form: carbonic gas (i.e., carbon dioxide) and water, in the presence of sunlight, combine to form sugar, with oxygen being emitted.  This was revolutionary.

It is often said that poets are among the first rank of true revolutionaries.  Certainly, Erasmus Darwin was at least a catalyst for the revolution in chemistry in the late 18^th century.  He made better scientific judgements than the committed scientific experts of his era.  How much this has to do with poetry may never be known.  What is known, however, is that a poem and not a scientific paper at least in this instance of the so-called ‘water controversy’ led to very real changes in science.

Lateral Science:

Albert Einstein once said: Everything should be made as simple as possible, but not simpler.  This general statement is also true within the context of teaching, especially science teaching.  Complex and challenging ideas have to be made as simple as possible, but without the introduction of inaccuracies due to oversimplifying.  So then, how simple is simple?

The teacher must be very comfortable with the material, in order to transform the complex into the less so.  The main interest of chemistry is matter, its make-up, and its interactions with other matter and with energy.  The standard chemistry definition for matter is that it has mass and that it occupies space.  Added to this, is that matter is ultimately composed of elements, whether of one type like pure copper or zinc metals, or a combination of elements as in brass which is an alloy of copper with zinc.  This definition is a longstanding, powerful and simplifying concept, but the truth is, it needs modification in the light of more recent observations, such as those made in the field of astronomy.

Astronomy is about more than just planets and stars. As a field of study, it also encompasses the origin of the elements, and the formation of materials from these elements. One thing it tells us is that the types of matter found on Earth may not be universal. Spectroscopic studies of X-ray, ultraviolet, visible, infrared and radio emanations from extraterrestrial sources have demonstrated that atoms and molecules of the types found on Earth are widely distributed in the universe.  On the other hand, other forms of matter have also been identified, forms of matter which confound our usual definitions and the ways in which chemists normally treat matter.  The usual statements, “We can classify all substances as either elements or compounds made up from mixtures of elements”, and “nature has provided 92 elements out of which all matter is composed”, are now seen to be misconceptions.

The simple facts are that the elemental composition of the universe is continually evolving, not all of the 92 elements referred to above occur naturally on Earth, and there are forms of matter made up of other than elements and their compounds.  Perhaps the conscientious teacher can address these ideas, as well as the origin of elements, by side-stepping into a bit of astronomy. Let’s call this “lateral teaching” which would hopefully induce lateral thinking on the part of the students. The concept of lateral things was first expressed in a succinct way by Edward De Bono in 1966.  It involves moving sideways to look at things in a different way. Instead of fixing on one particular approach and then working forward from that in what might be termed vertical thinking, the lateral thinker tries to find other approaches. This can involve many specific techniques, but the essential gain is that the creativity involved, in thinking up and/or changing approaches for learning, will become a useful tool. So let’s look at what a chemistry student can learn from a few classes in astronomy.

Some elements that consist of only radioactive and short-lived radioisotopes, like element-43, technetium, would not have survived long enough after being created in supernovae to be incorporated into Earth. In fact, technetium-98 which is used on a regular basis as a tracer in medical diagnosis has to be artificially synthesised.  Other heavier elements from element-83, bismuth, and above, with the exception of thorium also would not have survived, but these can be found on Earth because they are being continuously created from the radioactive decay series of various uranium and thorium radioisotopes.  In the end, there are only 90 naturally occurring elements on Earth.  The others we have identified are synthesized in natural stellar processes.

In the life cycle of a star, there are late stages known as white dwarf star, neutron star and black hole, each of which contravene our usual definitions of matter. The first two definitely have mass and take up space, but they are not entirely composed of elements and/or compounds. Because of the gravitational conditions present, collapse of these objects although it should be inevitable is avoided by the formation of what astronomers call degenerate electron and neutron gases in the white dwarf and neutron stars respectively. Black holes defy all attempts to apply the usual definitions of matter.  They have mass and their even horizons define a finite volume but one that does not occupy space to the exclusion of other objects. Particles inside a black hole are thought to fall towards a point singularity which does not occupy a three dimensional volume. Black holes absorb matter, but are they themselves matter?

Current research provides good evidence for additional “unseen” mass in galaxies, which so far has only been detected by the effects of its gravity on visible matter and light.  This is referred to as “dark matter”, or the “missing mass problem”. Some estimates project that a significant fraction of the mass of the Milky Way, perhaps as much as 99% of the mass of galaxy clusters, cannot be accounted for. It may be that dark matter does not interact through electromagnetic fields, which of course would make it very different from matter composed of the elements. If such estimates turn out to be true then we would have to admit that the known elements constitute only a minor part of the mass of the universe.

Another phenomenon is that of particle beams, made up of various isolated particles that have mass, or more precisely, rest mass or mass energy in a relativity context.  Examples would include alpha particles, electrons, neutrons, pions, positrons and so on, which some might argue are the building blocks or parts of atoms of elements, but they do not exist in bulk forms and it is not clear whether they occupy space.  Such particle beams and other phenomena, like black holes, are examples for which the commonly taught definition of matter is not at all useful.  This failure can be used to illustrate the care required in formulating fundamental definitions.  What does it actually mean to “occupy space”?  And, can matter and energy really be definitively separated, especially in view of Einstein’s equation for mass energy equivalence.

It is perhaps worth noting that Einstein’s discomfort with the accepted ideas hundred years ago about what mass is, led him ultimately to the general theory of relativity. He did not fall into the mind-set of the time, perhaps akin to those we now teach. Sometimes it is painfully obvious that people are forgetting that science is merely a collection of vulnerable theories. And, as Albert Einstein once asked: What does a fish know about the waters in which he swims all his life?