Revisiting lawn, 12 years on

 The problem is that publishing is no longer a profession for gentlemen, or if you wish, for ladies. The industry is full of nervous nellies going me-too, gimme whatever sold last year. 

Now any wannabe author will say something sour about publishers who lack vision and gumption, but I've got runs on the board. I have published over 60 volumes in seven languages (I count USian as a separate language) and I have a stack of awards for doing beautiful books, but when my books go out of print, that's that as far as they're concerned, and when I want them to consider something completely different, they shriek and hide in the cupboard.

The book shown above went well with Pier 9 in 2009. It won no awards, but people liked it because it was different. In fact, just this year, I have had a number of media requests (a documentary is in the air, an interview with a major journal, requests for articles and students getting in touch to work on projects). It has proved to be a solid and workmanlike piece, but now it was hard to obtain.

Now because I have been dealing with cloth-eared lumps of anteaters' phlegm in various publishing houses, I have become a dab hand at knocking up book-length ideas into e-books, and more recently into print-on-demand, using the services of Amazon.

There are people out there who need my ideas, the benefit of my knowledge and research, and in a bit under five days, I have taken my old manuscript, edited it and written new bits, and redesigned it, using my own illustrations and photos that I took to use in the original book. 

It's now up there and running, $5 for the e-book (which has colour) and $20 for the book with pages that have no colour, unless you colour them in. The ideas and the words are the same, and here's a sample. The dinkus in the break shows Edwin Beard Budding, demonstrating his prototype lawnmower, in 1831. Read on, and try not to dream, tonight, of the horrors of grass sports before the mower came into use.

Go here for more information on the book.

And by the way, The Speed of Nearly Everything is almost complete as well. 

Sample: How civilisation died

Nobody set out to deprive us of our hard-won weekend leisure, to divert our conversations from philosophy, literature and science to anterior cruciate ligaments, groin injuries and all the Grand Guignol of sports played on lawn. It just happened — and the lawn mower done it, when it changed the sports.

In olden times, “sport” meant cockfights, bear-baiting, bare-knuckle fighting and public executions, to nominate just a few of the gentler pastimes of yore. Football, when it happened, was a barely subdued form of warfare, generally played between competing mobs of unspecified size, following Rafferty’s Rules over unmade and unmowed ground. Most sports were not played by gentlefolk or gentle folk.

In its early days, cricket could be brutal or even fatal. As we will see, in March of 1751, Frederick Lewis, Prince of Wales, (the father of King George III), died of an internal abscess. This was caused by a blow from a cricket ball some months earlier. George III took the throne in 1760 when his grandfather died, thanks to a cricketing death that may have changed history, because the young king was probably too immature to deal with the American question.

Consider the fearsome (though perhaps mythical) tales of the fast bowler Brown of Brighton. Born in Stoughton in 1783, George Brown’s arm in the early 1800s was as thick as a normal man’s thigh. A professional, he played for Sussex and generally bowled to two long stops, one of whom always padded his chest with straw. Once, legend says, a nervous long stop held a coat out in a desperate attempt to halt a Brown delivery. The ball went through the coat and killed a dog on the other side.

For most people in the early 1800s, sport meant huntin’, shootin’ and fishin’. Robust team games were largely the province of muddied and bloodied oafs. Those were different days, but soon after Brown of Brighton died in 1857, many sports blossomed and acquired rules, officials, respectability and even a degree of social approval. Sport, in fact, became quite the vogue in the 1860s.

Grass and lawn had become popular, and so had events played out on lawn. The idea of lawn wasn’t new, and there had even been tennis-like games played on grassy surfaces in the time of Good Queen Bess, but these amusements simply hadn’t caught on with the mob. Something was going on in the late 1850s and early 1860s to make lawns more approachable, more acceptable for sport and leisure.

I thought I had found the answer when I was researching a history of the changes that happened around 1859, the year Charles Darwin published The Origin of Species. Most of the heavy work for New York's Central Park was done in 1859, and then I read about a sheep being struck by lightning in London's Hyde Park in July, 1859. Remember the sheep for a moment, because we'll come back to it later on.

I recalled that Amsterdam's Vondelpark opened to the public in 1865, and I thought I had the link, that a fad for public parks in the 1860s must be behind the change in attitude. That notion died when I discovered that London's Hyde Park was there in Oliver Cromwell's time.

Grand folk had lawns at the start of the 1800s, others had grass or meadows. Stately homes, palaces and university colleges had been lawn places even longer, but now the new rich wanted lawn as well, though only the richest could afford them at first. George Washington’s deer trimmed his grass, but they were kept away from the house by a ha-ha, a fence concealed in a ditch. Closer in, skilled servants trimmed the deer-free grass with scythes, but even a skilled worker might slip with the scythe and produce uneven surfaces, unsuited to putting practice, lawn bowls or croquet.

Animals made smoother surfaces, but there was a drawback. Imagine the feelings of a footballer who was tackled and landed heavily face-planting into a fresh cowpat or the leavings of a scouring sheep. Imagine the anguish of the slips fieldsman, similarly sullied as he dived for a low ball, or the dismay of a lady seeing her hem becoming mired in it. Feel, if you will, with a tennis player, facing a serve that splashes through a fresh plop. No, the lawn was better admired at a distance, back when animals were in charge of trimming it.

This brings us to Edwin Budding, who, as we will see, modified and enlarged a cloth-trimming machine to mow grass. Budding’s patent expired in 1855, bringing in a golden period for cylinder mowers in Britain between about 1856 and 1863. The lawn mower changed our world forever, but lawn could only emerge when people’s properties offered enough space for lawn to fit. Californian and Australian gold funded a new and enlarged middle class, a mob with social ambitions.

So people acquired lawns, but because display for display’s sake was a bit undignified, they needed to be seen to be using their lawns. They needed croquet, lawn tennis, clock golf, lawn darts, lawn billiards, archery and other lawn amusements and games now lost to collective memory. But they were naturally competitive, these lawn-owners, or they would never have been lured onto the lawn treadmill.

So it is hardly surprising that sporting associations and sets of rules were swiftly created, and ground was set aside for tourneys and competitions for these lawn games, but this all came after the lawn mower revolution of the 1860s. In a related change, around 1860, all true Britons concluded that the best way of turning boys into men is through games with maximal violence and close contact with mud, sweat and grass to ready them for a life of blood, sweat and tears, shed for the glory of the British Empire. Croquet, a game of repressed viciousness and brutality, trained future imperial overlords in the art of one-sided diplomacy.

By the 1860s, lawn games were plentiful, but croquet seems to have been the domestic leader. It came to England from Ireland in the early 1850s (though a variant was played by Languedoc peasants in the 1300s). From England, it then transferred to both Australia and the USA and took off in the 1860s, once the lawns were good enough and safe to walk on. Soon the croquet lawn was considered an essential possession for the civilized English-speaking family.

In golf, the first British Open was played in 1860, and before long, the wild Scottish golf links, clinging on in salt-sprayed dunes had become the sedate golf course of the rest of the world. The first Melbourne Cup, still one of the great horse races in the world, was run in 1861. The Football Association was formed in Britain in 1863, though the first inter-club match of football, the game known to heathens as “soccer”, was played at the end of 1860. The Rugby Football Union was formed in 1870. None of this could have happened if the playing fields had still functioned as part-time sheep and cow paddocks.

Most popular spectator sports seem now to be those played on carefully prepared grassy fields, or on artful surrogates for turf. Almost all major team games began on blemished grass surfaces that we would now dismiss as cow paddocks (which they were!). Without the lawn mower and the tireless pursuit of smoother, truer playing surfaces, modern sports would not exert their hold on us. No scythe, no sickle, no herd of animals could deliver the greens, courts and fields that we now expect for our games.

I regret the passing of the flocks of sheep. I cannot consider the start of the luncheon interval in a cricket match without seeing in my mind’s eye, groundsmen opening the gates at the northern end to introduce a flock of sheep to give the outfield a quick trim, with perhaps a posse of sheepdogs guarding the wicket. Perhaps I have a perverse mind’s eye to dream of an ovine Oval, but it could easily have been like that. A modern Brown of Brighton might risk killing the odd recalcitrant sheep which refused to be ejected at the resumption of play. Stand at deep fine leg, sheep, and one snick could make you mutton, just like that!

By 1898, professional players had started dividing up the gate takings between them, sports journalists and writers were hard at it, making allegations of match fixing and other wickedness. There were already more watchers than players and the onlookers were scathed for their indolence, their drinking and their betting on what the critics saw as degraded ghosts of Roman gladiatorial contests. The phenomenon of the Golf Bore was noted, and the Golden Age of sport was over, declared the pundits.

Away from the playing fields, seedsmen, makers of lawn sprays, fertiliser, watering devices, weeding devices and other lawn-tending tools and impedimenta were conspiring to divert the leisure time and wallet of the sports-watcher or even the player to pursuing the impossible dream of the truly ideal lawn. In suburbia, those who could no longer compete on the playing fields struggled to produce the finest green swards.

As humanity greeted the 20th century, lawnsmanship emerged as the new sport for the non-sporting. Independent, democratic and anarchic grass was oppressed by the mower to make servile lawn. Francis Drake probably played bowls on a daisy-strewn camomile lawn, now it was played on manicured monocultures of a boringly uniform green.

While we weren’t looking, before Queen Victoria died, we lost the struggle to have a restful weekend of quiet enjoyment, absorbed in a good book and intelligent conversation. Civilisation-as-it-might-have-been was snuffed out, and the killer is easy to find. The means, opportunity and motivation are all there. The lawn mower done it!

The book on Darwin? That's another title that is in my sights for revival. Mr Darwin's incredible shrinking world is its name, and it is the only book I know of that discusses crude oil before oil wells; seahorse teeth; eating moles, lions and pumas; an opera written by Charles Dickens; getting relief on trains before they installed toilets; testing fireproof safes and treating diphtheria.

Publishing may no longer be a profession for gentlemen, but this gent is about to bust into it. There's an e-book from the publishers, but the dead-tree market is wide open.

An odd theory about oil.

 Some fuels, like peat, coal, and perhaps oil may be derived from the fossilised remains of plants and animals. Standard wisdom says all the oil and coal that we find is organic, and so must have originated with organisms.

This is testable in some cases: we can certainly find plenty of fossils in coal, confirming that coal was formed when dead plant and occasional animal matter was buried in a swamp under the right conditions. We can see peat, brown coal, black coal and anthracite, and we can show that these are always found in sedimentary rock. We call these energy sources fossil fuels because we regard them as a form of buried solar energy, fossilised sunshine.

Every so often, a scientist comes up with what sounds like a totally crackpot idea. That is, in terms of what other scientists believe, it is a crackpot idea. Alfred Wegener wanted people to accept the idea of continents moving, and people dismissed him as an eccentric or a fool. Louis de Broglie made the crazy suggestion that electrons might really be waves, and almost failed to get his doctor’s degree because of it.

Wegener died without recognition, though his theory of continental drift (which we now know in an amended form as plate tectonics) is standard stuff in your textbooks. Louis de Broglie was luckier, because Albert Einstein heard about de Broglie's strange idea, and suggested gently that de Broglie might in fact be correct, and de Broglie lived to see the electron microscope (which treats electrons as waves) become a standard laboratory tool.

Wegener’s case is a bit more typical, for few ‘crackpots’ get an easy time of it. More than that, most of the crackpot ideas turn out to be wrong. Yet without those strange ideas, science would never grow. Thomas Gold had to comfort himself with that thought, each time a geologist sneered at his ideas about where oil comes from. That, and the knowledge that scientists can change their minds.

Scientists usually work with a particular paradigm until evidence arises to make the old paradigm unacceptable. There have been many failed paradigm shifts, because scientists are only swayed by the evidence. When the scientists proposing a change are as astute and capable as the late Thomas Gold was, people need to ask themselves what evidence they should look for, either to support or refute the paradigm shift that Gold offered.

Gold was a famous physicist, one of three astronomers who worked out the steady-state theory of the universe, which has now been replaced by the Big Bang theory of the origin of the universe. He lived to see that theory overthrown, and now he was attacking an older, and more deeply accepted theory. He could not accept that our world’s hydrocarbons are biogenic, made by living things.

When we first discovered petroleum, said Gold, it was close to the planet’s surface, and chemists then thought that the only place you found carbon chemicals was in living things. They even named carbon chemistry organic chemistry, because it was the chemistry of organisms. Oil was made of organic chemicals, so obviously it had to come from organisms.

Now we know that comets contain ‘organic’ chemicals, and so does Jupiter. Nobody argues that the methane on Jupiter came from giant Jovians breaking wind, and nobody assumes there are little green people all over the comets, producing the organic stuff there. If we were to discover oil today, said Gold, we would never be so silly as to claim that it came from plants and animals, not with the knowledge we have now of other bodies in the solar system.

The geologists sneered at this. How much oil has been found in igneous rock? they asked. Gold accepted this question cheerfully. Not a lot, he said, because geologists are set in their ways, and they only drill for oil in sedimentary rock, where the oil sometimes gets trapped as it rises to the surface. He had, he claimed, extracted 12 tonnes of hydrocarbons from granite in Sweden, most of it coming from dolerite veins that have intruded into the granite from below. The veins either weakened the granite, or carried the hydrocarbon with them, he said.

The Arabian Gulf oil fields, according to Gold, have no common features at any depth, except that they are over an area of great seismic activity. This area contains 60% of the world’s recoverable hydrocarbons. From the mountains of south-eastern Turkey down to the Persian Gulf, the plains of Saudi Arabia and the mountains of Iran, there is a continuous band of oil-fields, but nobody can find an adequate supply of source rocks to account for the oil that is there.

There is simply no ‘coherent geology’ beneath the surface to explain why the oil is found there, he said. The rocks are of all types and all ages, with nothing in common. But they are all rich in oils, and the oils are chemically identifiable, right through the area. They must have a common origin, said Gold, but some of the rocks are fifty million years younger, and were formed when the climate, the biology, everything in the area had changed. According to Gold, there is just no way the oil could have come from the rocks that have formed since life evolved.

In other places as well, we find oil provinces that stretch much further than any surface geological features. The only thing that is common is the deep seismic activity.

Then we come to Gold’s other problem: where did the living things that supposedly formed the oil get their carbon? If they got it from carbon dioxide in the air, through photosynthesis, there could not have been enough for life to keep going. So, said Gold, there must have been a continuous supply of carbon compounds for life to keep going. On his calculations, the earth’s atmospheric CO₂ must have been replaced 2,000 times in the past 500 million years.

The source of our hydrocarbons, he suggested, is about 150 km below the surface, seeping upwards when it can. Look at Indonesia, he said, where the movement of the Australian plate is causing activity below the surface, and there are huge oilfields. Look at California, where two plates are separating. Look at the match-up between seismic activity and oilfields in the rest of the world, he said.

It was true, he said that we often find petroleum in sedimentary rocks, but that, he said, was merely because we have a paradigm that says that we should look in sedimentary rocks, and so we only drill oil wells in sedimentary structures.

We were trapped in a 19th century paradigm, he said, one that held, until well after Friedrich Wöhler synthesised urea and William Perkin synthesised the first organic dyes in 1856, a paradigm that is reflected in the very name of the science that Perkin initiated, organic chemistry.

Back in the 19th century, as people began to drill for oil and use it, they naturally assumed the carbon compounds were organic, formed from living things. Even Pluto has hydrocarbons, but where did Pluto’s methane come from? There are no swamps or cows on Pluto, yet there is methane there. These organic chemicals come from a distinctly non-organic background.

Just for now, the oil companies have not been rushing to take up exploration leases on the world’s granite belts. In the future, we might just see a paradigm shift that leads them to do so, but even then, the oil would still be fossilised sunshine in a sense, for all of the solar system’s other hydrocarbons must have had their origin inside the sun, or some other earlier star, and the stored energy in them is derived from a star’s nuclear furnaces.

That leaves me wondering about the Yarrabubba asteroid: might it have smashed into a large deposit of inorganic oil? The best answer: more research is needed. Science often says that.

A changing climate

Jens Galschiot’s installation
‘Unbearable’ in Copenhagen.

 In the savage illustration on the left, the J-curve skewering the polar bear reflects the graph of the unstoppable rise of atmospheric carbon dioxide, and the curve is made from lengths of oil pipe. Sometimes, art and politics go together very well.

Did you know scientists knew about global warming, well before we usually think? Today, reputable atmospheric scientists everywhere are certain that human activity is driving the modern changes in our climate, but in 1950 it was just a curiosity. Of course, ‘global warming’ is a bad description, so we call it ‘climate change’ now. Under any name, it’s the same beast, the same looming disaster, and we knew about it, two thirds of a century ago.

Nobody denies that the Earth is getting warmer, because the evidence is there, and it was apparent in 1950, when George Kimble reported in Scientific American that the northern limit of wheat-growing in Canada had moved northward some 200 to 300 miles (call it 400 kilometres), adding that farmers in southern Ontario were experimenting with cotton. While cotton seems not to have taken off there, he reported another trend that continues to this day, the northward retreat of the permafrost:

In parts of Siberia the southern boundary of permanently frozen ground is receding poleward several dozen yards per annum.

Was it a cycle? Kimble said the Domesday Book featured 38 vineyards in England in 1086, in addition to those of the Crown. He pointed also to the Greenland colony which was frozen out, back around the mid-1400s and other evidence that climates change. He looked at Biblical evidence on the distribution of date palms to show that conditions in 1950 were much those of Biblical times, providing a picture of a climate that fluctuates around a mean. Maybe the trends were all just part of one of those cycles.

Mind you, the knowledge that humans are to blame is even older, because the whole thing had been predicted. The problem before was that there was not a lot of hard science in the arguments, which come down to logic, reason, careful modelling—and interpretation that was likely to be biased by a generous serving of self-interest. That changed in the last ten years.

Before ‘global warming’, climate change was called ‘the greenhouse effect’. In cold climates, a greenhouse is a glass shed which lets sunlight shine in, where much of the radiation is absorbed and changed to heat. Glass is less transparent to heat, but a greenhouse does more than trap warmth that way: it also holds a body of warm air around the plants, and protects them from wind-driven evaporation. So while we still speak of ‘greenhouse gases’, it is rare to hear anybody mention the greenhouse effect these days, even if the term goes way back to those early predictions.

Still, 1950 wasn't when it all began. In the 1820s, Joseph Fourier realised that heat-trapping might occur. In 1896, Svante Arrhenius reminded us that both water vapour and carbon dioxide were ‘greenhouse gases’ (escaping that bad analogy is hard) and so water and carbon dioxide would play a role in making the planet warmer. 

He also considered changes that might be happening, and consulted Arvid Högbom, who just happened to know all about carbon dioxide sources and sinks. Carbon dioxide was coming from life forms when they breathed, from volcanoes, and from humans burning fossil and other fuels. The human additions were minimal, perhaps one part in a thousand was added by the burning of coal, and there were probably checks and balances. 

Let's say 1896, OK? I mean, that was the story, I thought, but in late March 2019, a circular from Rush Holt at the American Association for the Advancement of Science (AAAS, of which I am a member) drew my attention to Eunice Foote:

Let me add one interesting historical note that is not widely known. In 1856 at the AAAS Annual Meeting, the work of Eunice Foote was presented, showing that carbon dioxide is a heat-blanketing greenhouse gas that in the atmosphere could warm the Earth. This was years before the work of the men usually credited with the finding (Tyndall in England and Arrhenius in Sweden).

Well, that broke into my weekend a bit. Foote’s short piece in The American Journal of Science and Arts in 1856 begins on p. 382, and says: “An atmosphere of that gas [carbonic acid, CO₂] would give our earth a high temperature …”

Arrhenius thought it would take 3000 years to double the atmospheric CO₂ levels, if ever, but such a doubling would raise world average temperatures by 5 to 6°C. In 1896, when Arrhenius did his calculation, the CO₂ level was around 290 parts per million: in 2021, the value was estimated at 420 parts per million: we had travelled almost half of the projected distance in just 125 years. Now look at the angle of that pipe, the one skewering the bear!

To Europeans in the 1890s, the warming effect seemed nothing to worry about, because nobody had stopped to consider the cascades, the flow-ons that might be driven by that rise in temperature. A German chemist, Walther Nernst, even asked if it would be feasible to set fire to uneconomical and low-grade coal seams, so as to release enough carbon dioxide to warm the Earth’s climate deliberately!

In the 1990s, global warming was in much the same position that “continental drift” had been in, a generation earlier, with some of the scientists arguing furiously, even when they agreed on the main principles, and as in the puzzle of the wandering continents, the key evidence was right there. Mind you, when I covered the 2002 Spring Conference of then American Geophysical Union, there were no nay-sayers there. The problem is that so long as people can get away with saying “global warming”, we are once again stuck with a bad label, just as the early 1960s saw us hung up on “continental drift”.

The cost of disagreement and bickering is much higher with climate change. It mattered not at all if people disagreed about plate tectonics (except, perhaps, that it makes tsunamis like the 2004 Indian Ocean tsunami easier to understand), but under any name, global warming is likely to be a major disaster for humanity, and any delay has the potential to cost lives. To understand this, we have to accept some puzzling propositions.

The formation of sea ice in the northern Atlantic is probably what stops Dublin’s and New York’s ports being iced-in each winter. This is because the sea ice is largely free of salt, leaving a residue of cold brine that drives a current known as the Conveyor, which in turn drives the Gulf Stream. The Gulf Stream takes warm water from the Caribbean and swirls it up around the North Atlantic, contributing to fogs and breaking icebergs loose, but keeping northern ports warm and open, even in winter.

Just as the prion proteins of mad cow disease have more than one stable form, so do weather patterns, and if the weather once drops into a new stable pattern, we may not be able to bounce it back to where it started. Then again, as northern Europe freezes over, the fast-melting glaciers will be replenished, lowering sea levels. The increased snow cover will also increase the reflectivity of the northern hemisphere, and that may cool the planet down a little. We just have to hope it does not trigger a new stable pattern that happens to be an ice age.

The changes that might follow the breaking point are hard to predict. They are unlikely to be spectacular and major, and will probably act stealthily, when infrastructure, port facilities and cities are flooded, or when agricultural land is lost, either by being covered by the sea or as a result of drastically changed rainfall patterns.

If any significant amount of rock is exposed in Antarctica, this could lead to a low pressure zone over the icy continent that could change weather patterns around the world. It hasn’t happened yet, but we need to learn from history. Ten years ago, no politician would take a long-term view and force the changes needed in the next thirty to forty years, when most of them are elected for a mere three to four years, after which they have to face the voters again.

It’s easier to bleat plaintively that there is no real agreement among the scientists yet (even if there is), or that some eminent scientists believe in other explanations (they aren’t all that eminent: just look at where the funding of these “scientists” comes from). That load of bollocks saves the politicians from having to act—and the honesty of scientists in saying that they cannot be sure just how things will go wrong allows devious short-term opportunists to prate that “the scientists don’t know…”

Politics is a marvellous human discovery. It is a pity that politicians have yet to discover humanity and consider its prospects. It is likely that politics, dithering, duck-shoving and shilly-shallying will make this disaster happen. So long as the electorate value their comfort right now over the comfort of their grandchildren, they are doomed.

We must care about the young: they are delicate. I will turn to how the young develop next.

The case of the echidna's hind leg

 My friends and some careful readers may be aware that for the first half of this year, I have been engaged in writing about echidnas.

I explained how this came about in April, but I will add it here to save readers leaping around. I am a biologist by training, later a teacher and museum educator, and I now volunteer on land care in a sanctuary on Sydney's North Head. That said, I am best known as a writer of non-fiction for children, and it was in that role that I spoke in December 2020 at a kids’ lit function, where I described the adventures I had while rescuing an echidna from a locked drain in the sanctuary, a drain that was due to flood, that night.

It involved kneeling on a steel grille, handling a heavy, spike-covered echidna that was grimly hanging onto a steel ladder, putting me at risk of toppling head-first into a water-filled sump, but it was still amusing in hindsight.

Over coffee afterwards, three writer friends asked me, separately and within the space of a couple of minutes, if I was planning a book on practical echidna work for younger readers. My answers were, respectively, “Naaah”, “Maybe” and “You betcha!” My third and most convincing interlocutor started out assuming I would say yes, and before I could answer, she reminded me that most children’s books about echidnas are cloying, saccharine tales of how an anthropomorphic Eddie the echidna couldn’t play with balloons.

Those books aren’t about echidnas, they’re about overcoming disabilities, and while that’s socially useful, those books don’t advance the understanding of science or inspire curiosity about nature. I succumbed to peer pressure and launched into the work, though there would be less of the how-to stuff.

In January this year, the book was well under way, when a new paper in Nature caught my eye (I'm the sort of writer who stays on top of the facts).  This was the Zhou, Yang, Linda Shearwin-Whyatt, Jing Li. et al.  paper on monotreme genomics. Suddenly, the important story was too complex for young readers.

I may yet come back to do a kids' book, but the book I will start pitching to publishers next week is solid history and biology for intelligent adults. Part of the story is about how Europe (mainly London and Paris) learned about echidnas and how they reported them.

Sadly, some of the early reports got the hind foot wrong. The accepted wisdom now is that the monotremes were originally aquatic, more like the platypus, and had a trailing foot, like this dinkus that I sketched for the book.

This Pretre and Massard illustration from 1816 shows the hind feet as they ought to be, though some of the rest is fairly improbable, like the stance and the protruding tongue, which is normally very hard to see. Still, the artists got the feet right!

The next illustration is from the Illustrated Australian News for Home Readers, a sort of newsprint post card to be sent to relatives at Home, which meant Britain to recently arrived Poms.

The art work ought to have been prepared in Australia, and by then we had some excellent home-grown artists, but this was a truly sloppy bit of work.

So where did the error get started? George Shaw got it right in 1792, and when William Bligh (yes, the Bligh of Bounty fame) saw and sketched a freshly-killed one on Bruny Island in Van Diemen's Land.

As you can see from the small version of Bligh's sketch (seem here on the left), he had no trouble with the backwards legs, though that might have been dismissed by some. As a Vandemonian echidna, it would have been less spiny than the ones I see in Sydney.

Still, Waterhouse's 1846 A Natural History of the Mammalia, got the legs all wrong, so clearly. the word wasn't out there.

When you look at an actual animal, the feet are tucked in underneath, and can be hard to see, but over the past year, I have been gathering the evidence:

That brings me up to June 2021, when we were strolling through Sydney's Royal Botanic Gardens, and came across a giant representation of an echidna. As it happens, I know that there were echidnas in the Domain and Gardens in the 1960s, but I don't think they are there now, so maybe the artist had no live model to work on. As you can see, the foot is on backwards!

I reported this singular factual deficiency, but was told "I don't think we'll bother to change it now". So I'm dobbing them in as anatomical sluggards.

Finally, added in September, here's my best hind foot shot so far, taken 7 September on a new youngster at North Head:

And here's another angle:

There has been a hiatus

 It is 6 to 7 weeks since I posted last, and here is the reason: I have been clearing off the back burner of stalled projects and good ideas.

You see, I'm not getting any younger, but there's stuff on my hard disc that will go to waste if I don't get it out there. All I can say is hooray for Amazon Print On Demand and Amazon Kindle.

Old Grandpa's Book of Practical Poems is clearly a nod to T. S. Eliot in the title, but this is a collection  of 328 pieces of poetry and verse that I think every youngster should at least recognise by the age of 18. The idea came to me when I was reading A. A. Milne to a grandchild, and our discussion threw me back to a time when I was working for an online encyclopaedia, and delivering verse on request to teachers who emailed me.

Being methodical, I checked the text, formatted it correctly, sorted it by author and sorted authors by their dates, and before the operation went pear-shaped, I had more than 600,000 words of poems stored away. It's all stuff to read to kids, or for kids to read, a sort of Dead Poet's' Society to enjoy at home.

That's now all available as an ebook for Kindle, but also as a handsome volume in print, for less than $25.

They Saw the Difference is something completely different. For the past half century, I have been writing essays about how science came about. Many of them were broadcast on ABC Radio National, a few appeared in that online encyclopaedia, and others were first written for this blog, or as part of the more than 60 books  I have had published.

Once again, the print volume comes in at under $25, and for that you get >SQRT(2) * 10^5 words, which is two normal paperbacks worth.

I probably could have got either of these books taken up by a traditional print publisher, but the one I really want to go through the trad route is my next book, which is on echidnas.

You see,  publishers are wary of having two books by the same author on the market at the same time. I play all over the fretwork, and one of my books competes with any other, but there's no talking to the petals.

So not a word to anybody, OK? Normal service will be resumed next week.

Different rocks: the birth of geology

 Around 1670, Nicolaus Steno (1638 – 1686) spelled out a set of basic principles of geology which spread fast: by 1671, there was an English translation available. Here is a modern version that conveys the two laws Steno left for us:

The Law of Superposition: in a sequence of strata, any stratum is younger than the strata on which it rests, and it is older than the strata that rest upon it.

The Law of Original Horizontality: strata are deposited horizontally and then deformed to various attitudes later. That is, undisturbed true bedding planes are nearly horizontal.

Cross bedding Malabar, Sydney,
beds laid down in a sandbank at
a ~30º angle.

(It would seem that Steno never saw cross bedding like that shown on the right.)

When James Hutton found an angular unconformity at Siccar Point in Scotland in 1788, the sloping beds he saw had once been horizontal. This is a place where one set of horizontal sediments had been uplifted, folded and eroded, carved away, before other sediments were laid down over them. Below, you can see Hutton’s unconformity: the upper layer is the famous Devonian Old Red Sandstone, sitting unconformably on Silurian greywacke. The two rock types were different.

Hutton’s Siccar Point Unconformity,
Siccar Point, Berwickshire,
Scotland. [Wikimedia Commons].

An unconformity is a place where there has been a break in time, where the upper rocks fail to conform to the ones below. Seeing this led Hutton to believe that the earth was very old, but on theological grounds, he rejected the idea that a divine Creator would make an earth which would wear out, so he looked for a mechanism of renewal. In his view, the planet was some sort of perpetual motion machine. And so we got the uniformitarian principle, the idea that the forces now operating to change the earth’s surface have always operated in the same way. There were no catastrophes, said Hutton, just slow, steady change.

The result, therefore, of this physical inquiry is, that we find no vestige of beginning, no prospect of an end.
—James Hutton, Theory of the Earth, 200.

So what does an unconformity look like? As part of the work for another book (Mistaken for Granite), I set out to locate points where the bottom of the Sydney Basin (Triassic and Permian rocks) sat unconformably on the underlying older rocks. I know several places where the boundary can be seen. One is at Myrtle Beach, south of Sydney, where you can see the tilted metamorphic rocks below, and more or less horizontal rocks above. The gap is from Permian above to Ordovician below.

To set the scene, Australia is old, and at some time before the Permian, the surface of the land was Ordovician and Devonian rocks that had been heaved up, pushed around and eroded. Then during the Permian, part of the continent sank below the sea, and sediments started to be dumped on the old rocks below. Unlike the old rocks being buried, the Permian rocks still keep their horizontal strata that they were laid down in, and so were the Triassic rocks that later covered the Permian beds.

To geologists, this hand on the rock at Myrtle
Beach spans a gap of about 200 million years.

So how big is the gap? The Ordovician era, according to the geological time scale, was 485 to 444 mya (million years ago), while the Permian was 299 to 251 mya. So if the Ordovician rocks beneath were laid down at the close of business on the last day of the Ordovician, and the Permian rocks were laid down on the first morning of the Permian, the gap is 145 million years. At the other extremes, the gap might be 234 million years: on average, it is probably a gap of some 200 million years.

Budawang Ranges: the top is Permian conglomerate, over Devonian metamorphics, tilting ~20º to the left.

There is also another place inland, in a valley of the Budawang Ranges, where you can reach the absolute bottom of the Sydney basin. The Devonian era was 416 to 359 mya, while the Permian was 299 to 251 mya. So if the Devonian rocks beneath were laid down on the last day of the Devonian, and the Permian rocks were laid down on the first morning of the Permian, the gap is 60 million years. If we take the other extremes, the gap might be 165 million years: on average, it was probably a gap in the record of around 100 million years.

In 1785, James Hutton discovered a number of pink veins of granite, pushing their way up into the dark schist above, and this was the first record of dikes. All the igneous rocks form when magma cools: granite cools slowly, deep down and forms large crystals, basalt cools faster near the earth’s surface and has no visible crystals. Dikes arise when molten rock pushes up into cracks in the rocks above, and that is contrary to the idea that rocks are laid down in horizontal layers. Charles Lyell made much of this.

Dyke near Mt Etna, from Charles Lyell’s
Principles of Geology (1834), volume 3.

Suddenly, about 200 years ago, the world of rock-hounds was hit by a flood of apparent contradictions, observations that demanded a wholesale rethink. Just like climate change, new ideas were suddenly there—though was climate change really such a surprise?

We'll come to that next time, but rest assured, scientists are very good at spotting differences!

Different lines: the spectroscope

 

This is what undergraduates
understood by spectroscope,
even in the 1960s.

In 1802, an English chemist named Wollaston noticed a number of black lines in the spectrum of the Sun. Joseph von Fraunhofer (1787 – 1826) saw the same lines in 1814 and mapped them in more detail. He found 570 lines, and named them, according to their prominence. These days, better instruments can detect thousands of Fraunhofer lines across the solar spectrum, and Fraunhofer’s D line can now be distinguished as three separate lines. The new and improved instruments are now usually called spectrographs or spectrometers, but they are still used to dissect and examine spectra. Newton would have given his eye teeth to access one of them.

Fraunhofer’s newly-discovered lines were regarded as gaps in the spectrum, but each line represented a subtraction from a continuous spectrum, the removal of a key wavelength. This mystery stood for more than 40 years before Kirchhoff and Bunsen sorted it when Kirchhoff saw a similarity: some of the ‘dark’ lines in the solar spectrum matched ‘bright’ lines of emission spectra.

Fraunhofer lines, wikimedia
curid=7003857

The terms ‘dark’ and ‘bright’ are relative: in actual fact, the dark lines are only dark in contrast to the rest of the spectrum, and may even be brighter in absolute terms than the visible lines of an emission spectrum. What happened next is best described in Kirchhoff’s own words:

While engaged in a research carried out by Bunsen and myself in common on the spectra of coloured flames, by which it became possible to recognise the qualitative composition of complicated mixtures from the appearance of their spectra in the flame of the blow pipe, I made some observations which give an unexpected explanation of the origin of the Fraunhofer lines and allow us to draw conclusions from them about the composition of the sun’s atmosphere and perhaps also that of the brighter fixed stars.

These lines were hard to see. In his Decline of Science in England (1830), Charles Babbage referred to the problems encountered by an untrained observer. The ‘Mr Herschel’ in the story was William Herschel’s son, who later became Sir John Herschel, a good friend of Babbage, who named one of his sons Herschel Babbage, who was later a minor explorer in Australia.

Conversing with Mr. Herschel on the dark lines seen in the solar spectrum by Fraunhofer, he inquired whether I had seen them; and on my replying in the negative, and expressing a great desire to see them, he mentioned the extreme difficulty he had had, even with Fraunhofer’s description in his hand and the long time which it had cost him in detecting them. My friend then added, “I will prepare the apparatus, and put you in such a position that they shall be visible, and yet you shall look for them and not find them: after which, while you remain in the same position, I will instruct you how to see them, and you shall see them, and not merely wonder you did not see them before, but you shall find it impossible to look at the spectrum without seeing them.”

Over time, the instruments improved, and by 1864, William Huggins took the spectrum of a nebula. Before long, Doppler shifts (get the book!) were being measured on photographs of spectra, and we were on the way to the notions of expanding universes, Big Bangs and much more.

William Ramsay studied chemistry in Germany under Robert Bunsen, and in 1894, tackled a problem Lord Rayleigh had found with nitrogen. When nitrogen is made chemically, it has one density, when it is prepared by subtracting the other known gases from an air sample, it is slightly more dense. Ramsay remembered that Henry Cavendish had seen the same problem a century earlier, when he tried to combine all of the nitrogen in air with oxygen, but found there was always a bubble of gas left over. Ramsay heated gas with magnesium to make magnesium nitride, but still found a bubble of gas left behind, which was more dense than nitrogen.

Ramsay and Rayleigh had access to the spectroscope that Bunsen and Kirchhoff had introduced, and this revealed a spectrum which fitted no known element. They named the element ‘argon’, meaning ‘inert’. But, they reasoned, if there was one new element to fit into the periodic table (chapter 6), there should be more, one for each row of the table. Ramsay began the search, and looked at a sample of gas from a uranium mineral, cleveite, and found that the spectrum was that of a ‘metallic element’ previously discovered in the sun’s spectrum by Norman Lockyer, who had named it helium.

But what were the lines? The best way to answer this is to first go sideways for a bit. Glass is mainly sodium silicate, and no chemist who has ever heated glass in the flame of a Bunsen burner would doubt the sodium part. Like common salt, glass gives what looks like a distinctive yellow colour to the flame. We know now that there are actually two colours, with wavelengths of 589.592 and 588.995 nanometres, but for now, we can treat them as a single colour.

Fraunhofer’s newly-discovered lines represented a subtraction from a continuous spectrum, the removal of a key wavelength. If you view light that had passed through a medium rich in sodium, the ‘sodium colours’ are absorbed, leaving a ‘line’. As we understand it today, sodium ions in the flame absorb energy of that wavelength. The energy shifts an electron from a lower-energy orbital to a higher-energy orbital, and according to some ideas that we will look at later, that quantum, that very precise packet of energy, the difference between the two orbitals, is associated with a particular wavelength and colour.

If light passes through a cloud of sodium ions, light of that frequency will be extracted and used to ‘excite’ electrons. Later, the electrons drop back down to a lower energy level, and emit light of exactly the same frequency, but most of it goes sideways, so we miss seeing it in the light coming our way. Kirchhoff then described other similar experiments in which flames ‘doped’ with either sodium or lithium act as either absorbers or emitters on limelight and sunlight.

I conclude from these observations that a coloured flame in whose spectrum bright sharp lines appear so weakens rays of the colour of these lines, if they pass through it, that dark lines appear in place of the bright ones, whenever a source of light of sufficient intensity, in whose spectrum these lines are otherwise absent, is brought behind the flame.
— Monatsberichte der Akademie der Wissenschaft zu Berlin, October 1859.

Later, Anders Ångström would use spectroscopy to show there was hydrogen in the sun, Johann Balmer would explain the lines, and Norman Lockyer would find helium there as well, while William Crookes detected thallium without ever seeing it, by finding a green line in a spectrum from some residues in a sulfuric acid factory.

Jean Foucault, the inventor of Foucault’s pendulum (chapter 13 in the book), first discovered the way the emission and absorption effects are linked, but he failed to follow this through to a logical conclusion. Instead, it was left to Bunsen and Kirchhoff to reveal this discovery. And of course Bunsen and Kirchhoff used the heat of the Bunsen burner for their observations, but there was more to come, as readers of my book can see in chapter 10.

It cannot therefore be doubted that the extensive volcanic elevations constituting the high table-land of Armenia and the island Iceland have flowed from sources which were chemically identical… the mineralogical differences between those Caucasian and Icelandic rocks which present the same mean composition, are not less marked than those observed among other ferruginous rocks of plutonic origin.
— Robert Wilhelm Bunsen, Poggendorff’s Annalen, 1851, Scientific Memoirs, edited by Tyndall and Francis, 1853.

Now that was a difference!

Different light: Newton and the spectrum

This is the next sample from They Saw the Difference.

When I was three, my bedroom had the leadlight windows that were popular as a bit of middle-class poshness in the 1930s, when our house was built. These windows were made of small pieces of glass, held together between H-shaped strips of lead. Each window had one special piece of extra clear glass with bevelled edges, and these gave me one of the wonders of my youth.

The windows faced west, and at certain times of the year, when the low afternoon sun shone between the houses across the road, it hit these angled pieces of glass, and a small coloured patch appeared on my wall—my own private rainbow, captive in my room. 

Any triangular piece of glass will bend light, and the light is split because each of the colours is refracted by a different amount, because each colour has a different wavelength. If we want to see the effect well, it is best to use a narrow beam of white light, and pass it through a prism in a darkened room. Newton saw it, and wondered why the light was different.

A prism is just a solid figure that is essentially triangular in shape and made of a transparent material. Prisms are commonly used in physics to deviate or disperse a ray in optical instruments or laboratory experiments, or to deliver total internal reflection. Here is how Newton set up his investigation:

 

In this diagram, white light comes
from the right and is dispersed.

One thing is certain, this three-year-old was too late to make any original discoveries, because Newton completed his systematic study of the spectrum, long before I was born. In 1666 he saw the composite nature of white light while carrying trying to minimise chromatic dispersion in lenses, an annoying effect that had been known for about fifty years, when telescopes and microscopes gave images with coloured fringes. 

In 1672, Newton told the world how he had studied the ‘celebrated phenomenon of colours’. At the time, most people assumed that colour was a mix of light and dark, that the prism somehow added the colour. and Robert Hooke was one of the strongest supporters of this view.

With two neat experiments, Newton demolished Hooke’s ideas, and began one of the great feuds of science. (In case you don’t know it yet, science is driven by spotting differences, but there’s always room for personal differences, and many of the wildest brawls revolved around Newton. By comparison, Dart’s clashes with the Piltdown gang {see the last blog} were nothing!) 

In one experiment, Newton used a second prism to pull the colours back together again, and showed that the result was white light. Then he used a second prism and a slit to show that when a selected band of coloured light passed into the second prism, it passed on unchanged. Hooke’s theory was in tatters, and Newton had an enemy for life. Newton wrote no more on optics until after Hooke died in 1703. 

 In fairness to a rather peculiar man, Newton simply could not help bursting out with the truth, even if it got up people’s noses! Novelist Aldous Huxley assessed Newton this way: 

If we evolved a race of Isaac Newtons, that would not be progress. For the price Newton had to pay for being a supreme intellect was that he was incapable of friendship, love, fatherhood, and many other desirable things. As a man he was a failure; as a monster he was superb.

How Newton’s experiment
is often wrongly shown.

Newton’s experiment is often shown like this, upside down, with a triangular prism sitting on its base, the light coming from below, bending down as it passes through the apex and being directed further down on the other side. Newton used sunlight shining down (not up!) through gap in a window, and being bent through the apex of an upside-down prism to shine upwards onto a wall, 22 feet (7 metres) away. 

We know the sitting-on-its-base-prism picture is wrong, because of the angle of the incoming beam, and besides, the band at the top is ultraviolet (above violet), while that at the bottom is infrared, meaning below red. The prism had to be point-down. The room must have been darkened, with just one beam of light entering the room and throwing a pale spectrum onto the wall, red at the bottom, violet at the top. 

Newton called the colours ‘spectrum’, a Latin word meaning spectre or apparition, and he is said to have been the first to see a prism, but I wonder how many others had found their own private rainbows before him, given that he spoke of the ‘celebrated phenomenon of colours’. 

Those celebrated colours were just those of the rainbow, but how many were there? Almost everybody had their own version. In fact the spectrum contains an infinite number of colours, and the number we ‘see’ is subjective. Newton followed a Greek astronomer named Ptolemy who had said there were seven colours, and gave them the names we use today: red, orange, yellow, green, blue, indigo and violet. 

 He said he could not separate any further colours from any narrow band of light selected from the spectrum, but his set-up would never have given monochromatic light in any selected band, because the rays from the Sun are not completely parallel. He should have seen further separation, but perhaps he intended his ‘result’ to be taken only as an idealised case. Or maybe he fudged his experiment: he stated correctly that different colours are refracted (bent) through different angles, both in prisms and in lenses, and that was the important part. 

What we now call visible light is just a small part of a much larger electromagnetic spectrum, but as we will see in chapter 5, this took time to find, and it is important to note that this is just the range that we humans see. There are many insects, bees for example, which are different because they can see ultraviolet light. 

So how do you see something that cannot be seen? In 1799, an astronomer named Sir William Herschel was measuring the temperatures associated with different colours. He had been using filters to view the Sun, but he saw how some filters that he used when examining sunspots let more heat through.

This led him to wonder if different colours had different amounts of heat, and he used thermometers to measure the strength of heating along a normal spectrum. He did this because his observations made him speculate that: 

 …the prismatic rays might have the power of heating bodies very unequally distributed among them…If certain colours should be more apt to occasion heat, others might, on the contrary, be more fit for vision by possessing superior illuminating power. 

Herschel found a higher temperature near the red end, and testing just beyond the visible range, found an even higher temperature, so he named this radiation ‘calorific rays’. He showed that these invisible rays behaved like visible light, being reflected, refracted and transmitted, the same tests Heinrich Hertz later applied to his radio waves. 

Herschel delivered a number of papers on the subject to the Royal Society in 1800, describing several hundred experiments on what he called “invisible light”, and since then, infrared astronomy has increased in importance as more sensitive instruments to detect infrared radiation have been developed. We will look more at infrared and infrared astronomy in the book. 

Johann Ritter tested the ultraviolet end of the spectrum, using silver chloride to detect radiation beyond violet. Photographers would later use the way light makes silver chloride go black, but Ritter found that there was an invisible band of radiation, even better than white light at blackening the silver chloride, which we now call UV. 

To sum up, the visible part of the electromagnetic spectrum, ranging in wavelength from approximately 3.9×10-7m (violet) to 7.8×10-7m (red) (corresponding frequencies 7.7×1014 Hz and 3.8×1014 Hz, respectively). 

As Aldous Huxley reminded us, Newton was unpleasant. He mistreated Stephen Gray, he quarrelled with Robert Hooke over the inverse square law and his theory of colour, with Gottfried Leibniz over the invention of calculus, and with Christiaan Huygens over his theory of light. 

Even so, any one of Newton’s achievements would have been enough to ensure his fame, even without the apple. But did the apple really fall? We will never know now, but the tale was made popular by Voltaire, and Newton’s biographer and friend, William Stukeley, claimed Newton told him the story, so maybe there was a day when the apple fell, and made Newton wonder why it should be so. That is Newton’s greatest gift to us, that he asked why as often as he did, even inspiring poets like Paul Valéry and Alexander Pope, who wrote: 

Nature and Nature’s laws lay hid in night:

God said ‘Let Newton be.’ and all was light. 

Mind you, Sir John Collings Squire would later add:

It did not last: the Devil shouting ‘Ho, 

Let Einstein be.’ restored the status quo. 

Newton told Hooke that if he had seen further than others, it was because he had stood on the shoulders of giants. This may have been a snide dig at Hooke, but a similar remark had been made by many others, centuries earlier. Robert Merton has even written a whole delightful book (On the Shoulders of Giants), on the subject, tracing the earlier history of the aphorism.

It was once cited with this brilliant typo: 

Merton, Robert K., On the Shoulders of Grants: A Shandean Postscript, Harcourt Brace, New York, 1965. 

—Max Charlesworth, Lyndsay Farrall, Terry Stokes, David Turnbull, Life Among the Scientists, Oxford University Press, 1989, bibliography, 295.

Next, we'll look at the spectroscope and what it can do.

A Different Brain

 This is the first part of They Saw The Difference, announced here.

Dart’s original illustration of
the Taung child, 1925.

I have always told my students that the best actors go into law, the next best become teachers, and the leftovers go to stage and screen. The reader may justly conclude from this that when I teach (or write) I’m putting on a show.

About 1992, I prepared for work each day by slipping the fossilised toe-bone of a giant kangaroo into my shirt pocket, a child’s brain into one trouser pocket and its skull into the other.

<SFX> Brakes screech, voices off, shouting “Wha-a-at?”

To clarify, the skull and brain were fossils, 2 to 3 million years old, plus or minus a bit, and if the kangaroo toe-bone was real, museums around the world make casts of their best and rarest examples to sell to other museums, so what you see in a glass case or a lecturer’s hand is usually a copy, cast in resin from a mould of the original, and painted to resemble the original, which is somewhere safe. No matter, just having casts of the skull and part of its brain in my pockets allowed me to tell their story, as well as if I held the genuine relics.

Raymond Dart was an Australian teaching in South Africa in the 1920s. In 1924, he received two boxes of rocks on a morning when he was supposed to be getting ready to act as best man to his friend, Christo Beyers. Peeking into one of the boxes, he saw the cast of a brain lying loose, and in that, he saw something important.

Soon after the brain’s owner died, mud partly filled a skull, and this mud later hardened to rock. Technically, it was an endocast, a copy of part of the inside of the skull which closely reflected the brain, but it wasn’t any old brain—it was special, because of its small size and the position of its brain stem.

Interpreting fossils is an art and a science. Experts must know anatomy, how the parts work together, what small differences mean, and they work with those small differences. The position of the large hole in the skull where the spinal cord leaves the brain, the foramen magnum, was immediately obvious in the shape of the brain. Any animal with a brain stem like that had to have walked upright.

We cannot be certain how the Taung child died, but clearly the skull had ended up on its side in a lime-rich deposit, where the brain case was slightly more than half-filled with the mud which became the cast.

Dart saw that it fitted into a block of stone in the case, so a major part of the brain owner’s skull was probably there as well. He was a medical man, but fascinated by fossils, and he knew that this was important.  So was his friend's wedding, but afterwards, he itched to get back to his find.

The covering rock had to be carefully removed before the face could be examined, but a quick look at the cast was all Dart needed. The brain said this animal had a skull which attached to a vertical spine, lying directly below the skull, rather than behind it, as in chimpanzees and gorillas. The owner walked upright, like modern humans. Here is how Dart worked it out:

I was also convinced from the earliest period of my investigations that these creatures had placed great reliance on their feet for walking and running and that, consequently, their hands must have been freed for other tasks. This was implicit in the globular form of the skull which was obviously balanced on a more vertically placed type of backbone than that of a gorilla or chimpanzee. The improvement in the poise of the head implied a better posture of the whole body framework, since there must have been a relative forward displacement of the foramen magnum (the hole in the base of the skull which links the brain with the spinal cord).
—Raymond Dart, Adventures with the Missing Link, 1959, 11.

The people who interpret fossils work like Sherlock Holmes at his best. To those who can read, a glimpse of a document can be enough, but those who can read fossils can gain just as much from a single glimpse of just the right hint. At this point, Dart made a political mistake.

Even in the 1920s, a careful observer would have seen that the British Empire was already in decay, and there were few careful observers around, but there was a cast-iron rule: London is always right. When Dart reported his find in Nature in 1925, London came down on him like a ton of bricks.

His find (known as the “Taung child”, from where it was found and its obvious youthfulness) was small-brained and most British scientists were certain that any small-brained thing was no ancestor of theirs. Piltdown Man was the human beginning, they said: he had a big brain, and best of all, he was found in Britain! (There’s more on Piltdown in the Afterword, but you'll have to get the book to read that.)

Today, we might think Dart’s name for his find, Australopithecus (“southern ape”), was not the best name for an upright-walking individual, even one with a small brain, but Dart was trying not to draw too much fire upon himself. It didn’t work, but in the long run, the brain stem evidence held up and Piltdown was eventually shown to be a fake.

The true status of the Taung child lay hidden inside its jaw until 1987. In both humans and the other apes, the “adult” teeth emerge in a specific sequence. There is one order of appearance in humans, and a different order of tooth eruption in the other apes. Concealed inside the Taung child’s skull, teeth were erupting, and their pattern of development would tell us what the Taung child was, either human or ape. As there is only one Taung child, you cannot slice it up, just to see what is inside. You could take X-rays, but there is too much other material in the way, and the things we are looking for are much too faint.

For many years, it seemed as though we would never know what was inside the jaw. Then in 1987, Glenn Conroy and Michael Vannier had a bright idea. Instead of cutting the skull into thin slices, they made a series of virtual slices with X-rays, and fed the results into a computer, and used back projection to build up a three-dimensional picture of what was inside. Seeing how the Taung baby’s teeth were erupting would give the answer.

The researchers took their X-ray shots, just 2 mm apart, in three different dimensions: vertically, from front to back, vertically, from side to side, and horizontally. (They called it the sagittal, coronal and transaxial planes, if you prefer the technicalities.) The method is less important, but the answer was delightful:

…the Taung ‘child’ is not a little human, but just as important, it is not a little ape…
— Glenn C. Conroy & Michael W. Vannier, Nature 329, 625–627, 21 October 1987.

The whole answer was told in the differences: the Taung baby is a betwixt-and-between, a half-and-half, a missing link if you wish, and we would never have known if the two researchers had not decided to give it a CAT scan! Sadly, we had to wait another sixty years to find out what it was.

The story I told, over several years at the Australian Museum, was about how Dart saw a difference, and recognised a new scientific truth. This was just a few years after Conroy and Vannier had confirmed the role the Taung child’s people played in our origins, but there was more: I had human and gorilla skulls, that toe bone of the giant kangaroo and the matching bone from a horse. Always, it was about differences.

At other times, I talked to my audience about Edward Tyson (1651 – 1708), one of the unsung heroes of science, who persuaded Robert Hooke to pay seven shillings and sixpence for a 43 kg porpoise from a London fishmonger, so Tyson could dissect it. Back then, even experts like John Ray called the porpoise a fish, but Tyson’s Anatomy of a Porpess, published in 1680 showed the danger of judging a book by its cover. He said: “If we view a Porpess on the outside, there is nothing more than a Fish, but if we look within, there is nothing less.”

Tyson later dissected an infant chimpanzee which had died after being brought to London from Angola. While he referred to it as both a ‘pygmie’ and an ‘Orang-Outang’, the drawings show a chimpanzee, but Tyson’s book, filled with illustrations, showed for the first time just how close humans were to the other animals, and how they differed.

If Copernicus had removed the earth from the centre of the universe (something I describe in chapter 10), Tyson and his assistant, William Cowper, helped to remove Homo sapiens from a central position in creation. This change tied together humans and the whole of ‘lower’ creation. Tyson had taken one of the crucial steps towards recognising that evolution happened.

Next, back to Newton again…