Comparisons – Page 6 – Science-Education-Research

life has common chemical basis like the root words of a language family

An example of an analogy used by a scierntist,

"The overwhelming majority of living organisms, from the lowest bacteria to trees and men, are all built of a relatively small number (about thirty in all) of types of chemical molecules containing between four and forty atoms in each. Every chemical molecule has its origin in some previous combination, as certainly as every atom of every element. More complex forms, particularly in this or that organism, can be derived from those simple types, and the few cases which have been studied have been shown to be so derived.

From this it follows that there is only one predominating life, derived from one common chemical basis. This is exactly the same logic that shows, for example, that all so called Indo-European languages have a common set of root words, however much they have deviated afterwards."
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul

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researching the development of life is like inferring a play from the last few lines

An example of an analogy used to explain a scientific idea:

"In the account which follows an attempt is made to present the main outlines and the critical stages in the development of life from its inorganic origins. It is based essentially on two kinds of data-the geochemistry and physico-chemistry of the cooling planet, and the organic chemical composition common to all existing living organisms. Such an attempt reveals at once the large gaps that still exist, but it also reveals the lack of perfectly feasible research which is bound to help to reduce these gaps and to bring out others that may now be unsuspected.

The process is one which we can imagine as taking the form of a play divided into a prologue and three acts. The prologue introduces the scene on the surface of the primitive earth, and the first group of actors of an entirely inorganic kind which must start the play. The first act deals with the accumulation of chemical substances and the appearance of a stable process of conversion between them, which we call life ; the second with the almost equally important stabilisation of that process and its freeing from energy dependence on anything but sunlight. It is a stage of further synthesis and of the appearance of molecular oxygen and respiration. The third act is that of the development of specific organisms, cells, animals and plants from these beginnings. All we have hitherto studied in biology is really summed up in the last few lines of this act, and from this and the stage set we have to infer the rest of the play."
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul

[I am not sure if the 'stage' of further synthesis was a deliberate theatre reference.]

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new scientific instruments enable an armoury of experimental methods

An example of metaphor in scientific writing

"With these advances in understanding has come a much greater armoury of experimental methods. On every level of organization, both of structure and of energy change, new physical and chemical instruments are offering the biologist a range of opportunity unequalled since the first use of the microscope and of the balance in the seventeenth century. On the chemical level the introduction of radioactive tracers …For the determination of molecular structure, the use of spectroscopy, particularly infra-red spectroscopy, and of x-ray crystallography combined…Chemical methods themselves have enormously increased their range and accuracy…Differential chromatography…X-ray analysis can be extended…

…the development of the electron microscope, making visible in an immediately understandable form, structures from those containing a few score atoms to the limits of microscopic vision and beyond. We are certainly now in a Galilean phase of observational biology.

…the new phase microscopes, and the ultra-violet, infra-red, polarizing and reflecting microscopes provide an armoury which, though they cannot rival the electron microscope in resolving power, have…shown a power of chemical interpretation of structure greater than any other method, and having the additional enormous advantage that they can be used on living material."
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul

[I assume the reference to a Galilean phase of observational biology is intended to refer to the advances brought about by Galileo Galilei's telescopic astronomical observations]

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Many examples of science metaphors are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.

material aspects of a living system are the struts and levers of a machine

An example of the use of metaphor in scientific writing,

"The new interest in the physical nature of biological systems has coincided necessarily with the development of new physical tools, theoretical and practical. Of the former, by far the most important is the development of the quantum theory and its extension to cover at least in principle the theories of chemistry and to give precious indications of the far more complex phenomena of biochemistry and biophysics. Without exaggeration it can be said that the conception of quantum energy changes in chemical reactions is the most illuminating most effective new idea in modern biology. We begin to see now that the material aspects of a living system are but the struts and levers of a machine, the particular function of which is to effect energy interchanges, and that growth and assimilation are but means of achieving a metabolism consisting of enzyme promoted energy changes. Thus in a very physical sense process takes precedence over structure."
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul

The idea of the organism as a machine was not new with Bernal (for example, Descartes saw animals as automata, and humans as machines that also had a soul.)

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every existing organism is in a sense a fossil

An example of simile in a scientist's writing:

"An object such as a galaxy or an apple carries its whole significance only if we consider the stages of its development as well as its, instantaneous activity. The ostensible purpose of biology in unravelling the processes that occur in living things is at the same time the elucidation of the necessary stages by which they arrived at their actual structures. Present study throws light on past history and vice versa. Every existing organism is in this sense a fossil. It carries in it by inference all the evidence of its predecessors; and this remains the case even if we cannot read it clearly or at all. [Professor Haldane says No, it doesn't….It would have been better perhaps to have phrased the statement conversely as everything an organism contains is evidence of its predecessors .]"
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul [the parenthetical material is taken from a footnote Bernal added in response to a criticism by Haldane of his original phrasing]

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Many examples of science similes are listed in 'Creative Comparisons: Making Science Familiar through Language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.

galaxies and stars are alive

An example of the use of analogy in extending a scientific concept,

"These terrestrial limitations obviously beg the question of whether there is any more generaIised activity that we can call life. Biology in this respect is on a different basis from physics and chemistry in that it deals less with universals and more with contingents. It belongs to the kind of descriptive and interpretative studies we might more properly call 'graphies', including observational astronomy and geography. Whether there are some general characteristics, which would apply not only to life on this planet with its very special set of physical. conditions, but to life of any kind, is an interesting but so far purely theoretical question. I once discussed it with Einstein, and he concluded that any generalised description of life would have to include many things that we only call life in a somewhat poetical fashion. Any self-subsisting and dynamically stable entity- transforming energy from any source, or, as Haldane put it, 'any self-perpetuating pattern of chemical reactions', might be called 'alive' in this sense. The value of distinguishing it as an individual system or organism would only exist if the total phenomena persisted for a time appreciably longer than the periods or characteristic times of any internal processes it might contain. In this sense a galaxy or a star is alive, or, on a more terrestrial scale, a flame. Passing to a degree, of complication greater than the biological, we might talk of the life of a human culture or civilisation. All are characterised by birth, persistence and death."
J. D. Bernal (1951) The Physical Basis of Life, Routledge and Kegan Paul.

We do not usually consider stars, galaxies or flames as living beings in the same way as we consider a bacterium, an oak tree, or a horse as alive. Stars are commonly said by astronomers to be born, live and die. This seems to be a dead metaphor (that is, for astronomers these terms are almost technical terms, even if they may mislead novices).

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Here Bernal goes beyond metaphor to spell out characteristics of living systems which by analogy can be applied to galaxies, stars, flames, and cultures.

a self-subsisting and dynamically stable entity- transforming energy from any source / any self-perpetuating pattern of chemical reactions
if the total phenomena persisted for a time appreciably longer than the periods or characteristic times of any internal processes it might contain
characterised by birth, persistence and death

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there was a brilliant Pleiades of neurologists in Frankfurt

Example of the use of metaphors in a scientist's writing:

"…many practicing physicians…have succeeded in organising private laboratories and have brought honour to themselves and their countries through valuable biological discoveries. From among thousands, let us mention Virchow, who wrote his celebrated work on cellular pathology while a physician in Frankfurt; Robert Koch, a practicing physician in Potsdam, whose research breathed new life into bacteriology through fruitful technical advances and excellent observations; and the brilliant Pleiades of neurologists in Frankfurt (not a university city), where men such as Weigert, Ehrlich, and Edinger devised valuable research methods for histology."
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

[There could be a collective noun here – a 'Pleiades of neurologists'?]

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data are the scientist's real estate

An example of metaphor used in a scientist's writing:

"Hypotheses come and go but data remain. Theories desert us, while data defend us. They are our true resources, our real estate, and our best pedigree."
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

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in science luck favours the one who is tilling constantly the garden

An example of an analogy used to explain an idea about science,

"Thus, it is necessary to trust at least partly in chance, which can be encouraged by repeated series of trials that must be guided by intuition and as deep and accurate a knowledge as possible of the latest reagents and techniques emerging from chemistry and industry….chance smiles not on those who want it, but rather those who deserve it… In science as in the lottery, luck favours he who wagers the most – that is, by another analogy, the one who is tilling constantly the ground in his garden."
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

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histological preparation appears like a sphinx to the novice

An example of simile used in a scientist's writing,

"How often we find entirely new things in preparations, where our unsuspecting pupils saw nothing! This is due to the quick judgement that results from experience. And how many things probably escaped our attention when we were still inexperienced in microscopic technique and each preparation appeared like a sphinx defying understanding!
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

[The comparison here is to something which does not actually exist, so the reader is expected to appreciate the cultural reference.]

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blood cells move about like pebbles caught up in the force of a torrent

An example of similes used in scientific writing:

"Enraptured and tremendously moved on seeing the red and white blood cells move about like pebbles caught up in the force of a torrent; on seeing how the elastic properties of red corpuscles allowed them suddenly to regain their shape like a spring after laboriously passing through the finest capillaries; on observing that the slightest obstruction in the stream converted potential spaces between epithelial cells into actual spaces providing the opportunity for minor hemorrhage and odema …"
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

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The word 'laboriously' means with great effort,

"laboriously (adverb)…in a way that needs a lot of time and effort"
https://dictionary.cambridge.org/dictionary/english/laboriously

but so this is figurative language because the blood cells move due to the pumping action of the heart, so are not making any effort themselves. (This could be considered anthropomorphic, as for something to behave laboriously implies purposeful action.)

human brains pollinate like desert palms

An example of figurative writing in science:

"Human brains, like desert palms, pollinate themselves [sic, each other?] at a distance. However, for the union of two minds to occur and generate fruitful results through a book, the reader must become fully absorbed in what a master has written, must penetrate fully its meaning, and finally must develop an affection for the author. In science as in life fruit always comes after the realisation of love."
Santiago Ramón y Cajal (1999). Advice for a Young Investigator. The MIT Press. (Translation of 4th Spanish Edition, 1916)

That human brains pollinate like palms can be considered a simile.

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There is an extended metaphor here based on reproduction.

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