WHAT would an archaeologist digging in the remains of our cities two millennia from now make of our civilisation?

That’s a fine question, posed by long-time US archaeologist Eric Cline in the stimulating epilogue to his new book, Three Stones Make a Wall. Assuming that our noticeboards and signposts, if not our long-vanished emails and websites, are still decipherable in AD 4000, most large urban structures, such as highways, bridges, schools and even archaeological museums, should be easy enough to figure out.

But what about what Cline labels “the ubiquitous rectangular blobs of metal, plastic, glass and circuitry that seem to be associated with every skeleton”, frequently found clutched in a bony hand? Will future diggers know that these were once communication devices?

And what of the still more puzzling shrines or temples “complete with a goddess wearing a crown and with flowing locks”, located on virtually every street corner? “I think there is a good chance of misidentifying Starbucks as a religion,” jokes Cline. After all, a religious purpose is the typical explanation put forward by today’s archaeologists for anything incomprehensible that they find in ancient ruins.

Most of Cline’s book deals with the stories of dramatic discoveries since archaeological excavation became methodical, beginning at Herculaneum and Pompeii in the 18th century. These are selected from around the Mediterranean and a few other parts of Europe, the Americas, Egypt and the Middle East, with occasional forays into the rest of Africa and Asia. For reasons that aren’t explained, Russia, the Indian subcontinent, Japan, Australia and Polynesia don’t feature.

Interwoven with these stories are the careers and colourful personalities of some well-known archaeologists, such as Heinrich Schliemann at Troy and Mycenae, Arthur Evans at Knossos, Howard Carter at Tutankhamun’s tomb, Leonard Woolley at Ur, and the Leakey family in east Africa. There are some more recent pioneers too: underwater archaeologist George Bass, the excavator of Bronze Age shipwrecks in the Mediterranean, and David Stuart, Mayan script decipherer and the youngest person to receive a MacArthur Fellowship, at just 18.

“What of the puzzling shrines or temples with a goddess wearing a crown, on every street corner?”

Both the discoveries and the discoverers are illuminated by gritty fieldwork recounted from Cline’s experience at sites around the eastern Mediterranean, such as the ancient city of Megiddo in Israel, known as Armageddon to the Greeks. This area was the focus of his valuable 2014 book about the Bronze Age, 1177 BC: The year civilization collapsed.

The mix is an enjoyable and wide-ranging one. That said, the most original and clearly scientific sections of Three Stones Make a Wall are four chapters prompted by the questions non-archaeologists are wont to ask. How do you know where to dig? How do you know how to dig? How old is this and why it is it preserved? Do you get to keep what you find?

Cline patiently explains. Where to dig depends on the surveying methods. These range from people on foot fanatically scouring areas for artefacts, to aircraft scanning jungle terrain using aircraft equipped with laser tech (lidar), to the sophisticated interpretation of satellite images by individual archaeologists.

In 2010, for example, Cline and fellow academic Sarah Parcak purchased some Quickbird satellite imagery of the area around Tel Megiddo. “Almost immediately,” writes Cline, “we saw the outlines of what looked like a large building in a field right next the ancient mound.” The images had pinpointed the exact spot Israeli archaeologist Yotam Tepper had earlier proposed as the probable location of the camp of the sixth Roman legion during the 2nd century AD.

The two also found “an almost perfect match with other Roman camps”, like those built around the hilltop site of Masada, a fortress besieged by the Romans around AD 73. They shared the images with Tepper and his collaborator, who carried out remote-sensing of the site at Tel Megiddo, including ground-penetrating radar and electromagnetic surveys. Subsequent excavations revealed Roman-period coins, pieces of armour and roof tiles stamped with insignia of the sixth legion: it was definitely their camp.

As for the dating of artefacts, Cline rattles through radiocarbon and potassium-argon analysis, rehydroxylation, pottery typology, thermoluminescence and dendrochronology. However, he stresses, archaeologists must admit “a willingness to acknowledge that none of it is fixed in stone”.

For example, rehydroxylation can estimate the age of pottery on the basis of the rate at which it absorbs water after its original firing. But when it was applied to a medieval brick from the UK city of Canterbury, it gave an age of about 66 years. The brick turned out to have been accidentally re-fired when Canterbury was bombed in the second world war.

As for the question of who keeps what, finders are no longer keepers. “Not only don’t I get to keep what I find,” observes Cline, “I don’t think that other people should collect such items either.” The consensus among scholars, he says, is that there is a direct correlation between private collecting and the looting of ancient sites – as the recent destruction of ancient Syrian sites by ISIS shows so painfully.

It is difficult to disagree. And yet, how very much poorer would the world’s great archaeological museums be without the past donations of private (and often none too scrupulous) collectors.

This article appeared in print under the headline “Raiders of the lost phone”

“Isaac Newton imagined satellites in Principia Mathematica, but had no concept of their usefulness”

by Jack Copeland, Jonathan Bowen, Mark Sprevak and Robin Wilson, Oxford University Press

DURING the 20th century, any book calling itself The Turing Guide would have been inconceivable. But in 2017 we have a massive and extraordinarily wide-ranging volume about the life, work and influence of mathematician Alan Turing. This is despite his achievements being shrouded in official and personal secrecy at the time of his death in 1954, aged 41, and for decades afterwards. The new guide is the work of four editor-writers: Turing historian Jack Copeland, computer scientist Jonathan Bowen, philosopher Mark Sprevak and mathematician Robin Wilson.

In the 1960s, Turing was known only to a few mathematicians, computer scientists and philosophers – and to one science-fiction writer, Arthur C. Clarke. In his 1962 book Profiles of the Future, Clarke showed himself well informed about the Turing test for machine “thinking”, noting that: “An electronic brain that passed this test would, surely… be regarded as an intelligent entity” – like the computer HAL that Clarke would soon imagine in 2001: A Space Odyssey.

Turing encapsulated his own test in a humorous human-computer “conversation”, quoted in The Turing Guide. Human: “In the first line of your sonnet which reads ‘Shall I compare thee to a summer’s day’, would not ‘a spring day’ do as well or better?” Computer: “It wouldn’t scan.” Human: “How about ‘a winter’s day’? That would scan all right.” Computer: “Yes, but nobody wants to be compared to a winter’s day.”

But Clarke on Turing the man was (given the time of writing) much less well informed. He was a “brilliant mathematician” who “first indicated how thinking machines might be built” and then “shot himself a few years after publishing his results”.

Only between the 1970s and 2000 did a truer picture of Turing start to emerge, with the gradual declassification of the UK’s wartime codebreaking effort at Bletchley Park, and the publication in 1983 of Alan Turing: The enigma. This was an eye-opening biography by Andrew Hodges, a mathematician and gay rights activist, who provides a brief foreword to The Turing Guide.

A man of parts

This new version of Turing came in three parts. First, there is the theoretical founder of modern computing, with his 1936 paper “On computable numbers”. Then, there is the brain of recent plays and movies, which mostly focus on his key role in codebreaking, beginning with cracking the Enigma code in 1941 using the bombe, a machine he co-invented. Last, we have the man convicted of homosexual practices in 1952 and forced to take female hormones, and who fatally ingested cyanide at home probably by biting into a poisoned apple: a possible, but certainly not provable, suicide.

In 2009, Turing received a posthumous apology from the prime minister for this shabby treatment; in 2012, an extensive centenary celebration; and in 2013, an official pardon from the Queen.

Today, he is widely known as an intellectual warrior and has become something of a cult figure. Steve Jobs wanted his company’s bitten-apple logo to be associated with Turing’s love of apples. And in 2015, staff at the UK’s monitoring centre GCHQ queued out of their Cheltenham building to get an exclusive GCHQ copy of a new biography, Prof: Alan Turing decoded, by his nephew John Dermot Turing, who contributes a chapter in the guide.

Turing still lacks the final accolade of a statue in central London to complement that of his ultimate boss, Winston Churchill, who called the codebreakers “geese that laid the golden eggs – but never cackled”. As the editors write pointedly in their preface: “It is no overstatement… without Turing, the war would probably have lasted longer, and might even have been won by the Nazis.”

A handful of the guide’s 33 contributors worked at Bletchley and knew Turing personally. Their reminiscences can be fascinating, funny, even moving. Captain Jerry Roberts, for example, was a graduate student of French and German who worked on Tunny, Adolf Hitler’s code for communicating with his top commanders that Turing broke using a technique nicknamed “Turingery”. Roberts writes:”I have a strong mental image of him walking along the corridor in one of Bletchley Park’s Huts. With his gaze turned downwards, he was a shy and diffident man, flicking the wall with his fingers as he walked… he was not a warrior king. But at that juncture, he was the most influential man in Europe bar none, and we owe our freedom to him.”

Mathematician Peter Hilton worked on Tunny as an 18-year-old undergraduate. He recalls the priceless story of how Turing unexpectedly volunteered for the local Home Guard so he could become a first-class shot with a rifle. However, when filling in the standard application, Turing took the logical precaution of writing “No” against the question: “Do you understand that, by enrolling in His Majesty’s Local Defence Volunteers, you render yourself liable for military discipline?”

When he failed to show up for parades and was court-martialled, the colonel asked him: “Do you realise this is a very serious offence?” Turing calmly referred to his application. The colonel read it, then said, apoplectically: “You were improperly enrolled. Get out of my sight!”

On the German side, such military rigidity often supplied valuable clues to the British codebreakers. For instance, the tendency of Tunny operators to repeat a message that had gone wrong in transmission, without changing the wheel settings on their encryption machine, offered the codebreakers two not-quite-identical messages for comparative analysis. They termed these “depths”, as Copeland explains in his chapter, “Tunny: Hitler’s biggest fish”.

“Turing was the most influential man in Europe bar none, and we owe our freedom to him”

Of the book’s 42 chapters, Copeland contributes eight that he wrote alone and eight written with others. Bletchley veterans aside, most contributors are, like the editors, academics working in mathematics, computer science, cognitive science, artificial intelligence, philosophy – and biology. Including the latter specialism was just as well because Turing’s final work, his 1952 theory of morphogenesis, concerned the chemical basis for the evolution of patterns in nature, such as animal stripes, and the concept of artificial life.

There are, meanwhile, plenty of surprises. For example, a literature professor describes Turing’s interest in the paranormal, which led him to claim in 1950 that “the statistical evidence, at least for telepathy, is overwhelming”; and there is Turing the composer, responsible for some of the earliest computer music, recorded by the BBC in Turing’s Manchester labs.

Meaning of genius

Has anything significant been omitted from this authoritative collection? More reflection about Turing’s impact on gay rights might have been welcome. So would a separate chapter on the nature of his “genius”, given that the term is applied to Turing by so many of the contributors. Indeed, Copeland and Bowen finish their engaging and informative introductory chapter by describing Turing as a “shy, gay, witty, grumpy, courageous, unassuming and wildly successful genius”. Very true – but which of these adjectives also apply to other geniuses in mathematics, physics and invention, and which are unique to Turing?

Considering my admiration for most of the guide, it may seem odd to recommend Turing newcomers to start with Hodges’s book. But it makes sense: his biography has little mathematics, and largely non-technical accounts of codebreaking. The Turing Guide, on the other hand, varies enormously, from the wholly biographical to the highly technical – with the latter particularly apparent when describing Turing’s contribution to mathematics and codebreaking. Graduate to it.

Once you do, you will find the whole Turing (or as much as we can ever know). Inevitably for a collection and with someone of such diverse achievements, and unconventional personality and personal life, there will be many voices and angles on the same aspects of Turing, and repetition.

But it is, I think, pretty much the last word on the subject. And it will ensure that while we may never decode the whole of Turing’s mind, his name will never again be forgotten.

This article appeared in print under the headline “All around Turing”

500 years of Utopia: The quest for the perfect society – and the lost civilisation that found it

The past, present and future of earthly paradises in history, books and art

“In a century of excavations, we have found just one depiction of fighting“

“Who knows what the Indus script might reveal if it is deciphered?“

Eventual decline

AT GUGLIELMO MARCONI’s grand state funeral in Rome in 1937 – orchestrated with military-style pomp by the black-shirted Benito Mussolini – the largest wreath on the hearse, adorned with a Nazi swastika, was sent by Adolf Hitler.

As the funeral began (6 pm precisely, Rome time, on 21 July), telegraph and radio stations in Italy, the UK, the US and Canada fell silent. As did the 31 beam and wireless stations of Cable and Wireless’s global network, and others in China, Japan, the Middle East and Europe.

Everyone knows that Marconi was the main pioneer of wireless communication. Yet we are far less confident about just which parts of this invention were his own work, in contrast with the inventions of near-contemporary, Thomas Edison. Now, at long last, we are offered a clearer picture in Marconi: The man who networked the world, a deeply researched and almost all-encompassing biography by Canadian media studies academic, Marc Raboy.

Fascinating and influential though Marconi was, the man who emerges does not inspire warmth, either in Raboy or, perhaps, in most readers of his notably balanced book. As Marconi remarked in 1934 in an exchange with the principal of the University of St Andrews, UK, after the students elected him lord rector: “Have I done the world good, or have I added a menace?”

Radio transmission is one of the great inventions of all time. But in Raboy’s view, “Marconi’s greatest invention was himself”. Most of his massive biography is therefore devoted not to wireless science and technology per se but to its profound ramifications for national and international business and politics, and for the complicated identity of Marconi.

He was a man full of inner dissatisfaction, a womaniser with generally troubled personal relationships, including a failed marriage. Among men, Marconi “didn’t really have friends, only associates”, remarks Raboy. By contrast, “He courted women who challenged him but married two who would never have dreamed of doing so.” Raboy concludes: “Something was missing… perhaps a result of his mother’s unconditional devotion; he always, painfully, sought and was never able to find that in a companion.”

A permanent outsider who longed to belong, Marconi was born in Italy in 1874 to an Italian Catholic father and an Irish Protestant mother, made his name and fortune in imperialist Britain at the turn of the century, and became a visiting celebrity in the US and Canada. He eventually returned to Italy to embrace Mussolini and Italian fascism, including the attack on what is now Ethiopia in 1935, when Marconi offered to serve in Africa. In his later years, he spent much time on the yacht he bought in 1919: a floating lab he named Elettra, after electrum: the Latin for amber, which creates a spark when rubbed.

“Fascinating and influential though Marconi was, the man who emerges does not inspire warmth“

In the mid-1920s, Marconi’s company started short-wave radio transmissions using the so-called Marconi beam system. These rapidly supplanted the cabled telegraphy introduced in 1830s, and led to the global connection we take for granted in our mobile telephony and the internet. The beam concept was Marconi’s, but its key technology was an antenna designed by Charles Franklin, his employee, close colleague and collaborator, who went on to design the antenna for the first BBC television transmission in 1936.

After Marconi’s death, Franklin wrote of his boss with a mixture of respect and criticism: “His scientific knowledge was weak, his engineering knowledge was weak, but he had a damned lot of intuition and common sense. He may have initiated the beam system but he didn’t know a thing about it.”

Franklin’s analysis certainly applies to the most famous episode of Marconi’s tumultuous career. It was 1901 and Marconi was in Newfoundland, waiting for a signal to cross the Atlantic from a spark transmitter in Cornwall, UK.

At that time, physicists were convinced by the electromagnetic theory of James Clerk Maxwell and unaware of the existence of the reflecting ionosphere. They were sure that such long-distance atmospheric transmission was impossible because all electromagnetic waves travelled in straight lines, like light beams, and could not bend to follow Earth’s curvature. Marconi ignored conventional wisdom and ploughed on with his experiment. As Raboy writes, his “tinkerer’s experience… made it happen by following hunch and intuition rather than scientific theory”.

But, as with his later beam system, a crucial element in Marconi’s 1901 equipment was not his invention: the sensitive detector known as a coherer. Originally conceived by French physicist Edouard Branly in 1890, Marconi’s 1901 coherer was created by an Italian collaborator, Luigi Solari. He apparently based it on an unpatented mercury-based design by Indian physicist Jagadish Chandra Bose, published in the Proceedings of the Royal Society in 1899: a borrowing never acknowledged by the notoriously litigious Marconi and neglected, surprisingly, by Raboy.

Marconi’s very first coherer, undoubtedly based on Branly’s, caused a sensation when he demonstrated it in public lectures by William Preece, the engineer-in-chief of Britain’s Post Office in 1896-1897. Concealed in a black box with an electric bell on top, the coherer could receive a signal from a spark transmitter that rang the bell, no matter where Marconi placed the black box, and without any visible connection between transmitter and box. There was immediate talk of “magic”, and comparisons with illusionist Harry Houdini. Even the University of Oxford called Marconi a “magician” in a speech conferring an honorary degree on him in 1904.

The coherer, now in the extensive Marconi collection at the Museum of the History of Science in Oxford, is reproduced in a new, superbly photographed guide to the museum. It is one of 35 intriguing objects taken from the museum’s collections, appealingly described by its director, Silke Ackermann.

These objects range from a metal astrolabe constructed by Muhammad Muqim al-Yazdi for Shah Abbas II of Persia in 1648 to a paper “photogenic drawing” John Herschel made in 1839 and a flask of penicillin culture made by one of its developers, Howard Florey, around 1940 – plus a blackboard chalked by Albert Einstein in Oxford in 1931.

Marconi’s coherer certainly ranks with astrolabes, photography and penicillin. But as portrayed by Raboy, the man seems to me much closer in intellect and personality to, say, Steve Jobs than to Einstein. Despite Marconi’s limited original contribution to technology and science, we shall always owe him an enormous debt for his vision of universal communication.

This article appeared in print under the headline “The Marconi connection”

BIOGRAPHIES of Marie Curie tend to neglect her last two decades or so and concentrate on her scientific career up to the isolation of radium, for which she won her second Nobel prize in 1911. But, though scientifically less fruitful, her later years were in many ways the most eventful of her life.

In Marie Curie and Her Daughters, Shelley Emling focuses on this later era in the great scientist’s life. It included a controversial love affair with physicist Paul Langevin, a friendship with Albert Einstein, the establishment of the Radium Institute in Paris, her pioneering use of radiography on the French wounded in the first world war, her tours of the United States to raise money to obtain radium for her institutes in Paris and Warsaw, and her relationships with her daughters, scientist Irène Joliot-Curie and writer Eve Curie.

Science is not the strength of this book. Pierre Curie’s vital contribution and personality are rendered almost invisible, and Emling says little about the discovery of radioactivity by Henri Becquerel and the Curies in the 1890s – and botches the references she does make to the Curies’ legendary preparation of radium between 1899 and 1902.

Still, the book works well at a more personal level and inspires fresh admiration for Marie Curie’s dedication to science, ethics and individuals, particularly her two daughters. After working closely with her mother, Irène went on to win a Nobel prize for her work on artificial radioactivity in 1935, in collaboration with her own husband. Eve wrote a biography of her mother, Madame Curie, which was a worldwide bestseller in the 1930s and was adapted to make a Hollywood feature film in 1943.

Perhaps the most surprising part of the book, though, is to see how Curie’s welcome in the US in 1921 – by universities, companies and public figures including US president Warren Harding – enabled her to shake off her dread of the spotlight. Wisely or not, Marie and Pierre always refused on principle to patent any of their techniques, and so their radium institutes were long deprived of resources. By her 1929 US tour, she used her fame to help raise funds for her institutes’ research.

Yet as this latest biography makes clear, it never went to her head. As Einstein once remarked, “Marie Curie is, of all celebrated beings, the only one whom fame has not corrupted.”