Monthly Archives: March 2017

Imaging and imagining black holes

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Posted on behalf of Davide Castelvecchi

Until several years ago, most cinematic and artistic depictions of black holes — including many in the pages of Nature — failed to match the known facts. A black hole (the remnant of a runaway gravitational collapse) often looked like a space whirlpool, or perhaps a simple black sphere representing the event horizon — the surface that constitutes a point of no return for anything that falls inside. This would be pictured either against a background of stars, or surrounded by an ‘accretion disk’. (Think Saturn’s rings, but made of superheated plasma and spiralling in at close to the speed of light.)

Thanks in part to physicist Kip Thorne’s involvement,Christopher Nolan’s 2014 film Interstellar was the first one to show what you would actually see if you were to fly near a black hole (see image here). And as I wrote last week in Nature, an ambitious radio astronomy project now aims at taking the first snapshot of an actual black hole. In other words, a real-life picture of Interstellar’s black hole Gargantua, if a highly pixelated one.

Between accurate art and actual observation, it might finally begin to sink into our collective imagination just how weird these objects must look. Gravitational lensing, a consequence of Albert Einstein’s theory of gravity, makes light rays curve around a black hole — some light rays do so multiple times. This means that ironically, even though a black hole forever hides what has fallen into it, it cannot hide anything that lies behind it. In particular, if there is an accretion disk, gravitational lensing produces multiple images of it, which appear to wrap around the black disk of the event horizon like a halo (see the infographic accompanying my article).

A black hole cannot hide another object (in this case another black hole) that passes directly behind it. Instead, the object in the background will appear like a ring surrounding the one in the foreground.

A black hole cannot hide another object (in this case another black hole) that passes directly behind it. Instead, the object in the background will appear like a ring surrounding the one in the foreground.{credit}Alain Riazuelo/Institut d’Astrophysique de Paris{/credit}

Theoretical physicist John Wheeler famously made the term ‘black hole’ official in 1967 to describe the phenomenon. Fewer realise that around a decade after that, an astrophysicist accurately portrayed a black hole, as Thorne relates in his splendid companion book to the film, The Science of Interstellar. In 1978 at the Paris Observatory, Jean-Pierre Luminet became the first to make a detailed computer calculation of a black hole’s appearance. He did so, he told me, by programming a (by then already obsolete) 1960s IBM 7040 computer, using punch cards.

Because Luminet had no way to print out the resulting image or visualize it on a screen, he used the data to draw an image by hand, putting individual dots of India ink onto a photographic negative. He published it that year in the French magazine La Recherche, and then with more detailed technical results in the journal Astronomy and Astrophysics in 1979. (On his blog, Luminet explains how calculating the appearances of black holes is technically similar to understanding the optics of glories, atmospheric phenomena similar to rainbows.)

Given that Gargantua is an accurate simulation using twenty-first-century knowledge and computing, it is uncanny to see how Luminet’s hand-drawn picture made from a punch-card computer’s data already had all the crucial ingredients. In fact, in one respect it was even more accurate. In Luminet’s image, one side of the accretion disk (the one rotating towards the observer) looks much brighter than the other — a consequence of its extreme speeds. As Thorne notes in his book, the Interstellar team considered including this effect in their renderings, but director Christopher Nolan decided it would be too confusing for viewers. This was possibly the only aspect in which the Gargantua sequence strayed from scientific accuracy.

The first accurate image of the appearance of a black hole (India ink on Canson negative paper).

The first accurate image of the appearance of a black hole (India ink on Canson negative paper).{credit}Jean-Pierre Luminet{/credit}

That realism was a long time coming. From the 1970s at least, most popular-science renderings of black holes lacked the effects of gravitational lensing. “I was a little bit upset to see that in many popular magazines, they more or less systematically used artistic views with no scientific accuracy at all,” Luminet recalls. Starting in the late 1960s, science-fiction had also battened onto black holes, but under an intriguing array of names. A 1967 Star Trek episode had a ‘black star’. A 1975 episode in another TV series, Space: 1999, involved a ‘black sun’. Films, too, began to feature black holes, including  Disney’s 1979 The Black Hole.

Meanwhile, the rise of powerful computers in the decades after Luminet’s efforts meant researchers made ever more realistic simulations, and began to craft colour animations. In the early 1990s, the late astrophysicist Jean-Alain Marck, also at the Paris Observatory, created the animation at the top of this piece, which Luminet later used in the documentary Infinitely Curved. Even more spectacular animations were created by Alain Riazuelo at the Paris Institute of Astrophysics and by Andrew Hamilton at the University of Colorado in Boulder. (Hamilton also rendered what happens when you fall inside a black hole.)

However, none of these outreach efforts had the same impact as Interstellar. The film has begun to affect the way artists represent black holes, says Eugénie von Tunzelmann, who led the 200-strong team of computer-graphics experts at London-based company Double Negative, which created the special effects. Stylized icons now often look like a strip crossing a circle – suggestive of the accretion disk and its lensed image. “The first thing that comes to mind when people say ‘black hole’ might have changed.”

Even in relatively inaccurate sci-fi representations, black holes still provided inspiration for young minds – including for many kids who grew up to become researchers and perhaps work on projects such as the Event Horizon Telescope (EHT), the radio astronomy project that plans to image real black holes. “A lot of scientists, and maybe especially astronomers, always carry that little flame within them,” says Sheperd Doeleman, an astrophysicist at Harvard University in Cambridge, Massachusetts, who helms the EHT. “It really gets you thinking about what’s possible.”

Davide Castelvecchi is senior physical sciences reporter at Nature. He tweets at @dcastelvecchi.

Notes on the animations:

Colour Animation of a Black Hole with Accretion Disk (top): this shows the gravitational lensing around the event horizon (Jean-Alain Marck; from the documentary Infinitely Curved).

A Journey into a Black Hole (bottom): a simulation of what an observer would see while falling into a black hole (Andrew Hamilton).

 

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.

A wily plotter and his pioneering atlas

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Posted on behalf of Rosalind Cotter

A colour version of the Britannia strip map showing the route from Newmarket, Suffolk to Wells-next-the-Sea, Norfolk.

Figure 1 One of the ‘Principal Roads of England and Wales’ displayed in John Ogilby’s Britannia atlas. It shows the route from Newmarket in Suffolk to Wells-next-the-Sea in Norfolk. As well as towns, villages, bridges and churches, these scaled strip maps record every wood, common, ford and metal mine along the way. {credit}Wikimedia Commons{/credit}

When it comes to unearthing facts and piecing them together into a bigger picture, scientists arguably have it easier than historians. The forensic scientist has recourse to DNA, soil and pollen analyses. The astrophysicist and molecular biologist have big data and an arsenal of technology to collect and unravel it. Even the palaeontologist has a formidable taxonomic lexicon to fall back on. Historians have to make do with piecemeal facts and shadowy context, guided by sources that are often incomplete, unreliable and open to misinterpretation. They cannot systematically test their hypotheses or devise controls to shore them up.

Remarkable, then, to take a little-known seventeenth-century cartographer, shake together a kaleidoscope of disparate facts from his long life, and apply them to tease out a sinister political strategy, all carefully concealed in Britain’s first road atlas.

In The Nine Lives of John Ogilby, Alan Ereira does just that. Ereira is a master story-teller, and his biography of Ogilby (1600-76) is a riveting ride never dulled by its meticulously referenced detail. The backdrop to Ogilby’s colourful life includes the Gunpowder Plot, the English Civil Wars, the execution of Charles I, the Restoration of Charles II, the Plague and the Great Fire of London. His career encompassed the eponymous “nine lives”, as entrepreneurial lottery founder, celebrated dance master to barristers, impresario, poet, soldier and sea captain, secret agent, publisher of deluxe editions of classics and – at the grand age of 70 – Cosmographer and Geographic Printer to Charles II.

Portrait of John Ogilby (from a 1660 edition of Homer's Illiad).

Portrait of John Ogilby (from a 1660 edition of Homer’s Illiad).{credit}Wikimedia Commons{/credit}

Of these exploits, the most fascinating (and puzzling) to a scientist is the last. The king tasked Ogilby to draw up a road atlas of England and Wales as an aid to the fledgling postal service, but this was to be much more than a simple precursor of today’s motoring guides. Using a device he dubbed a “wheel dimensurator”, a push-along wheel 5 metres (16.5 feet) in circumference that incorporated a dial to record distance, Ogilby painstakingly compiled mile-by-mile strip maps of 73 roads (see Figure 1, above). Between them, these covered 12,070 kilometres (7,500 miles). He plotted details of natural and man-made landmarks along the way at a scale of 1 inch to the mile, a mapping standard later adopted by the British Ordnance Survey until the 1970s. The distances catalogued, allowing for land contours, accord to within roughly 5% of interpolations from Google Earth.

At that time, precision measurement was equated with scientific authority. Therefore the king commandeered physicist Robert Hooke  and architect Christopher Wren, both fellows of the Royal Society, to advise Ogilby. They devised questionnaires for the project’s surveyors to ask locals as they passed through villages:  strange questions, about possible landing sites and unusual tides, watercourses and locations of farms and metal mines. No expense was spared. The eye-watering production costs, equivalent to roughly half a billion pounds today (comparable with Google’s annual expenditure on Google Maps), were at odds with the impoverished state of the country after the English Civil Wars (1642-51) and the second Anglo-Dutch War (1664-67).

The stupendous efforts of Ogilby and his surveyors and engravers culminated in a magnificent volume comprising 100 plates, Britannia, published in 1675 (its resplendent frontispiece is shown in Figure 2, below). Weighing almost 8 kilograms, it was hardly handy for travellers. The routes depicted were surprising too. Why London to Aberystwyth, a small place today and a mere fishing hamlet in the seventeenth century? And why no mention of key commercial thoroughfares such as the road to Liverpool?

Figure 2 The frontispiece of John Ogilby’s Britannia. The gateway is flying the royal standard and bears the arms of the City of London. In the foreground, a map is being made by surveyors at a table of instruments. The three distant figures on the right are working with Ogilby’s measuring wheel: one is pushing it, one is cleaning the mud off, and the horseman behind is making notes and checking the direction of travel on a compass. Curiously, they are moving along a small track and not along the main highway. This and other mysteries, as well as secret codes hidden in the plate, are discussed in The Nine Lives of John Ogilby.

Figure 2 The frontispiece of Ogilby’s Britannia. The gateway is flying the royal standard and bears the arms of the City of London. In the foreground, a map is being made by surveyors at a table of instruments. The three distant figures on the right are working with Ogilby’s measuring wheel: one is pushing it, one is cleaning the mud off, and the horseman behind is making notes and checking the direction of travel on a compass. Curiously, they are moving along a small track and not along the main highway. This and other mysteries, as well as the secret codes hidden in the plate, are discussed in The Nine Lives of John Ogilby.{credit}Courtesy of Swansea University, Information Services & Systems (ISS){/credit}

Ereira picks up on all the signs that Britannia could be a military atlas rather than a postal one, as officially designated. The routes seem to have been selected for landing marching armies, punctuated with conveniently placed metal mines for producing armaments. There were Catholic shrines marked too — surprising in a Protestant nation. Ereira’s hunch is given credibility by the secret Treaty of Dover, drawn up in 1670 by Charles II with his cousin Louis XIV of France just before the start of the Britannia project. That secret lay hidden for almost 100 years.

The Treaty stemmed from Charles’ vulnerability to covert political and religious forces across the land, after nine years in exile during Oliver Cromwell’s interregnum. Charles’ solution was to seek direct power for himself. (His inspiration was Frederick III of Denmark, who set himself up as Europe’s first monarch to rule by absolute decree after a resounding victory over the Swedes in 1660 gained him immense popularity.) First, Charles needed a glorious military victory over the Dutch, preferably funded by France. But the price for French assistance would be to shift Britain back to Catholicism. The Treaty was duly signed. Ogilby, now turned spy, was commissioned by Charles to amass the information necessary for military back-up by French troops in the event of popular insurrection. They could land unobtrusively at any of the potential invasion points identified on the map as having a functioning roadway, such as Aberystwyth or Wells-next-the-Sea.

As it turned out, no such invasion was necessary. The victory over the Dutch was modest and contributed nothing to Charles’ popularity. There was no uprising. Instead, Charles achieved absolute power by dispensing with Parliament and using the information in Britannia to remove opposition town by town. Ogilby died the year after Britannia was published — but Ereira has given new life to this extraordinary man and his meticulously compiled roadmap.

Rosalind Cotter is Nature’s Correspondence editor.

 

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.

Revisiting Feynman on physical law

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Physics, along with jurisprudence, is principally known for its laws. And physical laws are amazing: they can predict almost anything, from the effects of gravity to why the Sun shines. Explaining them is surprisingly hard, however. Anybody first encountering them in the classroom, typically as mathematical formulae applied to abstract problems, can attest to that. The result is countless hours spent by teachers, educators and popularisers of science devising ways to make physics (and its laws) ‘more interesting’.

Richard Feynman’s The Character of Physical Law – published in 1965 and now newly reissued by MIT with a foreword by Frank Wilczek – stands out as an early example of a successful attempt towards this end. The book is based on a series of lectures the iconic physicist had delivered the previous year at Cornell University. But it’s a layered work, and clearly shows Feynman also drawing from another set of lectures, delivered at the California Institute of Technology from 1961 and 1963. Those would go on to become his most famous work: The Feynman Lectures in Physics (reviewed here).

However, whereas The Feynman Lectures were an attempt to reinvigorate the pedagogical approach to ‘freshman’ physics, The Character of Physical Law is, in Wilczek’s words, far more than an exposition of facts and ideas. It is also a character study of Feynman himself.

By physical law, Feynman is quick to explain that he means “the rhythm and pattern of phenomena of nature which is not apparent to the eye, but only to the eye of analysis”. In other words, the very phenomena we uncover through painstaking empirical observation, and tend to ultimately write down as mathematical equations. But the topic of the lectures is broader still. They focus on the characteristics common to all the laws: “that is another level, if you will, a higher generality over the laws themselves”.

The big picture

What is really striking about The Character of Physical Law is Feynman’s ease in covering broad areas of physics — for instance, the law of gravitation, the relationship between physics and mathematics, the role of symmetry in physical laws. But crucially, he is equally adept at discussing the history of these topics and their relevance to everyday life, and lucidly articulating the reasons why one might be curious about them. It is this combination of skills that allows him to avoid excessive abstraction and philosophising, a common pitfall when looking at the big picture of things.

For instance, Feynman kicks off by discussing the law of gravitation. In plain words, this describes how a particle is attracted to every other particle through a force directly proportional to the product of their masses, and inversely proportional to their distance. Though acknowledging that it is a discovery of the Enlightenment, he argues that by “describing its history and methods, the character of its discovery, its quality”, he recontextualises it for the present.

In the space of a few pages, the reader learns the way mathematician and astronomer Johannes Kepler established how the planets orbit around the sun. And they are provided with a clear description of the Newtonian mechanics that explain what makes them go around — including, of course, a brief explanation that, eventually, even Newton’s laws are found wanting and Einstein’s relativity takes over. At the next level of generality, Feynman also considers other instances in which inverse-square laws appear in nature — for example, to describe the interaction between electrical charges. The reader is invited to think deeper as each layer of description is peeled away, while at the same time keeping in mind the common threads that bind them together. Yet Feynman isn’t afraid to admit when even the boundaries of his knowledge are reached: “instead of having the ability to tell you what the law of physics is, I have to talk about the things that are in common to the various laws; we do not understand the connection between them”.

This approach certainly demonstrates an unusual depth of physics understanding. It also reveals Feynman’s humanity. Feynman was of course famously charming and charismatic — and, arguably, flawed, perhaps propagating the myth of his stage persona a little too enthusiastically. But ultimately he was, in my view, a man driven by a playful, down-to-earth spirit of curiosity, not the dry and abstract reasoning of a detached academic.

Rules of the game

As Wilczek notes in the foreword, a lot has happened in physics since 1965; yet The Character of Physical Law holds up extremely well today. My favourite chapter is the one on symmetry in physics. Feynman starts off by noting that symmetry appears to fascinate the human mind, if only for aesthetic reasons. But he chooses to emphasise the symmetry within the laws of physics themselves. Certain laws can be symmetric with respect to time and space, for example, but not necessarily under changes of scale. The implications of these symmetries are more obvious in some cases than others. But the key point is that by focusing on these underlying rules of the game, one gains an appreciation for the character of the physical laws they apply to.

To underline that, he masterfully explicates the far-reaching implications of charge-parity violation in the weak nuclear force. In his own words, “it is as if 99.99% of nature is indistinguishable right from left, but that there is one little piece which is completely different”. This ultimately explains the preponderance of right-handed molecules, such as proteins, that play a central role in the biochemistry of life. Feynman’s genius as a communicator lies in his ability to explain this connection in a manner that is accessible, fascinating and accurate in equal part.

Ultimately, I wouldn’t go quite as far as Wilczek by describing The Character of the Physical Law as the single best introduction to modern physics. Somehow, I suspect there is a reason why the more incremental approach espoused in The Feynman Lectures in Physics has gained traction with a wider readership over the years. But for the interested reader looking for more, this book offers enlightenment to those exploring its facets.

Andrea Taroni is chief editor of Nature Physics. He tweets at @TaroniAndrea. 

 

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.

Snapping Earth for more than seven decades

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The 'Blue Marble' image of Earth by the Apollo 17 crew in 1972.

The ‘Blue Marble’ image of Earth captured by the Apollo 17 crew in 1972. {credit}NASA{/credit}

For centuries, the only way to ‘see’ Earth whole was through globes and maps; its grandeur was merely glimpsed in mountain vistas or across a stretch of ocean. That changed in the 1940s, when the first images of the planet were snapped from rockets probing the border of space, 100 kilometres up. The imaginable became the visible.

Since then, satellites and spacecraft have beamed down shots from ever greater distances and in growing detail. Now Nature Video has captured the most iconic of these in the film Portraits of a Planet: Earth from Space.

These images have massively boosted science and technology – from weather forecasting to monitoring natural disasters, forest cover and climate change. And they have had a subtler psychological impact. Revealing this majestic, finite, vulnerable entity framed in blackness has elicited deep responses feeding into policy and culture.

Going ballistic

The first images of Earth from space — from 1946 and 1947 — were black-and-white, grainy and remarkable partly for the fact that they happened at all. Both were taken by cameras retrofitted into the empty nosecone of V-2 rockets, long-range ballistic missiles the United States captured from Germany at the end of the Second World War.

In 1946, all that protected the film during the rocket’s crash landing was a steel cassette. When the photos were first projected onto a screen, “the scientists just went nuts”, recalled Fred Rulli, a member of the rocket’s recovery team, in an interview with Air and Space magazine. The following year’s project nudged the rocket further into space to 160 kilometres, bringing more detailed images clearly revealing Earth’s curvature.

Taken in March 1947, these pioneering NASA images of Earth were the first taken from an altitude of more than 100 kilometres. Cameras retrofitted into the empty nosecone of V-2 rockets were deployed to take the shots.

Taken in March 1947, these pioneering NASA images of Earth were taken from an altitude of 160 kilometres – then a record high. Cameras retrofitted into the empty nosecone of V-2 rockets were deployed to take the shots.{credit}Johns Hopkins Applied Physics Laboratory{/credit}

The cold-war space race soon pushed cameras to greater heights. In 1957, the Soviet Union launched its first satellite, Sputnik; the US quickly followed suit. Three years later, the newly formed NASA put TIROS 1, its first weather satellite, into orbit, which sent video back to Earth using dual television cameras. TIROS 1 proved that such images could provide be used to monitor cloud formation, one of the first indications of the potential scientific power of satellites.

In 1960, cameras aboard NASA's first weather satellite TIROS-1 captured Earth.

In 1960, cameras aboard NASA’s first weather satellite TIROS 1 shot Earth.{credit}NASA{/credit}

Human-crewed efforts began with the orbital missions of Yuri Gagarin in 1961 and John Glenn in 1962. But it was not until 24 December 1968 that Apollo 8 astronaut Bill Anders captured arguably the most iconic image of Earth. Later dubbed ‘Earthrise’, it was the first to show the planet from the perspective of another celestial body, as a luminous blue hemisphere rising above the Moon’s horizon. Anders had had to fight to get the long-lens camera on board, and deviated from the craft’s flight plan to get the snap (as he wrote in his obituary of Glenn earlier this year).

That awe-inspiring image was a shot across the bows of the cold war. It was also transformational for earthbound observers: the moniker ‘Spaceship Earth’ gained traction as people fully grasped the planet’s limits. Ultimately, ‘Earthrise’ supercharged the nascent environmental movement in the United States particularly, pioneered by environmentalists, scientists and thinkers such as Buckminster Fuller; and it proved a trigger for the US Earth Day, which launched in 1970.

That grassroots clamour, bolstered by works such as biologist Rachel Carson’s 1962 Silent Spring, had an influence on policy shifts at the federal level. The period from 1970 to 1973 saw the Environmental Protection Agency established and the US Clean Air Act, Clean Water Act and Endangered Species Act passed. Anders notes, “I wouldn’t say [Earthrise] was the only reason, but it certainly was an important reason motivating folks to take better care of our planet.”

'Earthrise' - possibly the most iconic portrait of Earth - was captured by astronaut Bill Anders from Apollo 8, the first crewed lunar mission.

‘Earthrise’ – possibly the most iconic portrait of the planet – was captured by astronaut Bill Anders from Apollo 8, the first crewed lunar mission, in 1968.{credit}NASA{/credit}

The spectacular ’Blue Marble’ (see opening image), shot by the crew of Apollo 17 in 1972, fuelled further activism; it has been recreated by NASA many times over. The photograph captured Earth with the Sun behind the camera illuminating most of the globe, and from a distance (45,000 kilometres from the planet) no one has managed since.

Inspired by the potential of such astounding images, the US Geological Survey and NASA launched the first satellite in the Landsat programme in 1972, to chart Earth’s terrain in detail. Landsat satellites have documented burning oil wells in the first Gulf War, the impact of Hurricane Katrina and deforestation in the Amazon. Landsat’s false-colour rendering of Alaska’s Malaspina glacier, taken with a thermal imaging camera, is mesmerizingly beautiful.

In 1991, Landsat satellites captured lit oil wells in Kuwait , which burned for 10 months.

Landsat satellite images of lit oil wells in Kuwait during the Gulf War, in 1991. They burned for 10 months.{credit}NASA{/credit}

 

This Landsat image, shot in 200, captures the majestic flow of Alaska's Malaspina Glacier. This false-colour composite was created using infrared, near infrared and green wavelengths.

Shot in 2000, this false-colour composite showing the majestic flow of Alaska’s Malaspina Glacier was created using infrared, near infrared and green wavelengths.{credit}NASA/USGS{/credit}

In recent years, a parade of Earth monitoring and robotic exploration craft have added countless images to the file. In 2012, over 312 orbits, the Suomi National Polar-orbiting Partnership satellite built up a night-side image of Earth and its lit-up cities in ‘The Black Marble’. In 2013, NASA’s Cassini craft turned around in the outer Solar System to capture Earth — a pinprick of light — through the rings and moons of backlit Saturn.

Composite image 'The Black Marble' was taken by Suomi NPP, a joint National Oceanic and Atmospheric Administration and NASA satellite, in 2012

Composite image ‘The Black Marble’ was taken by Suomi NPP, a joint National Oceanic and Atmospheric Administration and NASA satellite, in 2012.{credit}NASA{/credit}

Called ‘The Day the Earth Smiled’, that shot was taken from more than 1.2 billion kilometres away, making it a far cry from the images of our planet revealed some 70 years ago. But while the photographs have become ever more impressive, rarely are they as powerful as those first images of the ‘ground beneath our feet’ in its sublime entirety.

'The Day the Earth Smiled', taken by NASA's Cassini craft in 2013, shows Earth through Saturn's rings. The image spans some 650,000 kilometres and is a mosaic crafted from photographs taken over four hours.

‘The Day the Earth Smiled’, taken by NASA’s Cassini craft in 2013, shows Earth through Saturn’s rings. The image spans some 650,000 kilometres and is a mosaic crafted from photographs taken over four hours.{credit}NASA{/credit}

Elizabeth Gibney is a reporter on physics for Nature based in London. She tweets at @LizzieGibney. 

 

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.

Orchids: the success of beautiful cheats

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image001One in seven flowering plants on Earth is an orchid. The Orchidaceae, one of the oldest, as well as the most extensive, families of flowering plants, comprises 749 genera and around 26,000 species. Some have evolved to survive in the most inhospitable of environments, pushing their sweet blooms through the sands of arid deserts or the icy soils of Arctic tundra. All this I learned from The Book of Orchids, a luscious coffee-table tome from Ivy Press (and the University of Chicago Press in the United States), coauthored by Tom Mirenda, Mark Chase and Maarten Christenhusz.

Orchids didn’t achieve their success by being nice guys. They are “Masters of deception and manipulation…famous for lying and cheating,” writes Mirenda, the Smithsonian Institute’s orchid collection specialist, in his introduction.

The book describes 600 representative species, with each photograph reproduced at life size. The selection shows off the aesthetic range of the family, from the startling beauty of Australia’s extravagantly multi-coloured Queen of Sheba (Thelymitra variegata) to the dull arum-leaved spurlip orchid (Pachiplectron arifolium) from New Caledonia, whose puny brown petals make it appear dead.

Introductory essays summarise the unlikely biology of the family and the threats to some of its species.

Queen of Sheba orchid (Thelymitra variegata)

Queen of Sheba orchid (Thelymitra variegata){credit}Maarten Christenhusz{/credit}

All orchids begin as a structure called the protocorn, a small ball of cells without roots, stems or leaves. For the embryo to develop, the protocorn needs to be infected by a fungus which provides it with the necessary sugars and minerals.

Nearly all orchid species share two other physical characteristics. Almost without exception, the male and female structures — the stamen and the stigma — are fused into a single column, which makes for unusually efficient pollination. And most orchids have one very distinctive petal that is modified — thanks to an unusual mechanism of genetic control — into a sort of lip upon which pollinators like bees, wasps or moths may land.

The lip is a main site of the orchid family’s deception. Pollinators land in the belief that its patterns promise something attractive, like nectar or a mate. The repertoire of scams in the orchid family is as broad as its range of beautiful form and colour. And the tricks are mean. Flowering plants generally use traits like colour or scent to attract pollinators, and then reward them with nectar so that they return regularly. Most orchids don’t bother with the reward. The pollinators, unsurprisingly, quickly learn not to be fooled.

Lazy Spider orchid (Caladenia multiclavia){credit}SOF/K. Senghas{/credit}

But that doesn’t bother the orchids. Because of their unusual structure, orchid flowers load vast amounts of pollen onto the back of a naïve insect during its first visit. That load is readily scraped off onto the thousands of ovules in the next flower it visits while it is still working out that it is being cheated. Vast numbers of seeds result from a single encounter.

Orchids can fool by mimicking characteristics of other flowers which do give rewards — some produce look-alike nectar spurs that contain no nectar — or by aping the sexual hormones of insects. Many species have evolved multiple fake lures. The lazy spider orchid (Caladenia multiclavia) from south-western Australia, for example, attracts a local wasp both with sex pheromones and an insect-like silhouette.

Orchids’ sense of entitlement extends to their relationships with fungi, which get nothing in return for their efforts in supplying orchid embryos with vital nutrients. Though some orchids do provide sugars with fungi as they mature, others continue their unrewarding exploitation lifelong.

Lady Ackland's cattleya (Cattleya aclandiae)

Lady Ackland’s cattleya (Cattleya aclandiae){credit}Eric Hunt {/credit}

Meanwhile, humans are doing what they can to challenge orchids’ survival skills. Many species are under threat from collectors supplying them to manufacturers of faddy foods, drinks and therapies. Some of the most beautiful species, like the Queen of Sheba or the Malaysian slipper orchid (Paphiopedilum rothschildianum) are threatened by poachers supplying horticulture.

The Book of Orchids numbers 100,000 cultivars, mostly hybrids, in the horticultural trade. Few reach general retail outlets. For orchid-lovers like myself who select from the offerings of their local garden centre, the book offers (alas) no advice on how best to look after these beauties, but raised my respect for them to a yet higher level.

 

 

Alison Abbott is Nature’s senior European correspondent. She tweets at @alison_c_abbott.

 

For Nature’s full coverage of science in culture, visit www.nature.com/news/booksandarts.

Artist of the animatronic

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3Q: Giles Walker

The Last Supper, Giles Walker's art installation at the London Science Museum's Robots show (multimedia).

The Last Supper, Giles Walker’s art installation at the London Science Museum’s Robots show (multimedia).{credit}Giles Walker © The Board of Trustees of the Science Museum{/credit}

Not all roboticists are scientists or engineers. Giles Walker, an artist in Brixton, south London, specialises in turning scrap metal into animatronic sculptures — ‘art robots’ that do not involve AI. Walker uses low-tech, unashamedly cheap technologies to animate artbots: car windscreen wiper motors for big clumsy movements, radio-control servos for delicate ones, coordinated via a communications protocol used in theatre lighting. His replica of the 1928 talking tin man Eric is a star of the London Science Museum’s Robots exhibition (reviewed here). Another of Walker’s works on display there, The Last Supper, enters darker territory. This animatronic ‘ensemble piece’ involves 12 mechanical figures sitting around a table. The figures — many with faces that are humanoid, yet smoothly featureless — talk about sin and forgiveness. A doll-like sculpture of a naked child backed by a cross stands on the table. It’s a bizarre scene, packed with a sense of foreboding. Here, Walker explains what’s important when building a robot for art’s sake — and what makes it all worthwhile.

What sets animatronic figures apart?

Everyone immediately likes mechanical or kinetic art. People are drawn to moving things. If they see them as a robot, they are even more drawn. Robots appeal because they have such cult status already: old ones, because you see a relatively naive picture of the future held by people of the past; new ones, because they offer a glimpse into the future that may be just as naive. And I think attempts at replicating humans, whether in Frankenstein or a robot, have always fascinated people.

Detail, The Last Supper.

Detail, The Last Supper.{credit}Giles Walker © The Board of Trustees of the Science Museum{/credit}

What are your criteria for your mechanical figures?

You see these robots coming out of Japan. Mine, by comparison, are very low budget. You can only afford a certain number of motions, so you think about movements that say the most about the character you are trying to portray. They don’t look human, but they behave in a human way. It could be through just a telephone or handbag — I give them a human trait that is instantly recognisable. The characters I create always tend to have fallen through the safety net of society. I built a ‘homeless’ character (Outside the Box) a few weeks ago to make a point. Few pay attention to a homeless person; the irony is that everyone pays attention to a homeless robot. I crafted it so that when people walked past, it told its stories. I didn’t fashion it like a Hollywood cliché.

Giles Walker.

Giles Walker.

There is an idea of robots as utopian, but that is not quite true. Funding for robotic development mainly comes from the arms trade or medical science, either to make us kill each other more efficiently — drones, Big Dog — or to help make us live longer, using nanotechnology, robot-assisted da Vinci surgery or exoskeletons. Such advances make you wonder whether have we really developed as a species or are just cancelling ourselves out. My machines are not positive icons of the future. They will not improve our lives by being a more efficient workforce, freeing up more leisure time for the working man. They are lost ‘souls’, redundant, the technological remnants society has discarded on its accelerating trajectory. Most of my sculptures, including those in  The Last Supper, smoke. Robots aren’t supposed to smoke. The juxtaposition of having a mechanical figure show, perhaps, a human weakness creates an opportunity to hold a mirror up to our own species and play with its eccentricities.

Are there surprises when your creations ‘come to life’?

It’s the best moment. You build them to formula – one elbow move tends to be the same as any other. But when you first see all the joints moving at the same time, that’s the peak. If you make it do a certain move, it encapsulates everything that you have been trying to say with that character. That’s the buzz, that’s what you do it for. You fire it up for the first time, and it will have this nervous tic in its neck, and it’s like, yes! Then you can start fine-tuning it.

Interview by Celeste Biever, Nature’s chief news and features editor. She tweets at @celestebiever. Robots runs at London’s Science Museum until 3 September. The Last Supper shows there until 29 May. (View the installation in action here.)

 

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