It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Drones dive into aviation's deepest enigma as MH370 hunt restarts
Published: 30 Dec 2025 -
AFP
Washington: Nearly 12 years after Malaysia Airlines flight MH370 vanished with 239 people on board, the search for answers to one of aviation's most haunting riddles resumed Tuesday in the remote southern Indian Ocean.
Armed with cutting-edge deep-sea robots and smarter data, US investigators are scouring the seabed for clues that have eluded governments, experts and grieving families for more than a decade.
MH370 took off from Kuala Lumpur just after midnight on March 8, 2014, bound for Beijing on what should have been an uneventful six-hour flight. Less than an hour later, its transponder went dark, wiping the Boeing 777 from civilian radar. Military screens later showed the aircraft veering sharply west, crossing back over Malaysia before heading south over the vast Indian Ocean.
What followed was the most ambitious and costly search in aviation history, as multinational teams combed more than more than 46,000 square miles (120,000 square kilometers) of seabed off Western Australia with ships, aircraft and sonar. They found nothing.
The hunt was called off in 2017, leaving families with heartbreak and a mystery that spawned theories ranging from hijacking to deliberate pilot action. Now, the Malaysian government has given the green light for a fresh attempt led by Texas-based marine robotics firm Ocean Infinity under a "no find, no fee" contract, according to a statement from Malaysia's transport ministry.
"The latest development underscores the government of Malaysia's commitment in providing closure to the families affected by this tragedy," it said. The company will pocket $70 million only if it locates the wreck, reports said.
This new phase, expected to last up to 55 days, targets a tighter search zone of about 5,800 square miles -- far smaller than earlier efforts and pinpointed using updated satellite data, drift modeling and expert analysis.
Keeping the hunt alive
Ocean Infinity is unleashing autonomous underwater vehicles that can dive nearly 19,700 feet (6,000 meters) and stay submerged for days at a time. The drones use high-resolution side-scan sonar, ultrasound imaging and magnetometers to map the seabed in 3D, detect buried debris and pick up traces of metal. If something promising appears, remotely operated vehicles can descend for close inspection.
Ocean Infinity, which also has a control center in Britain, led an unsuccessful hunt in 2018, before agreeing to launch a new search this year. AFP reached out to the company for comment but there was no immediate response.
Only fragments of MH370 have ever been recovered. Since 2015, fewer than 30 pieces believed to be from the aircraft -- bits of wing, landing gear and fuselage -- have washed ashore thousands of kilometers apart, from Reunion to Mozambique.
No bodies have ever been found
Malaysia's official probe concluded in 2018 that the plane was likely deliberately diverted from its course, but stopped short of assigning responsibility. Relatives from China, Australia, Europe and beyond have fought for years to keep the hunt alive, arguing that closure matters not only for the dead but for global aviation safety.
Governments in Beijing and Canberra have welcomed Malaysia's decision, pledging support for any practical effort to crack the case. Chinese national Jiang Hui, who lost his 72-year-old mother Jiang Cuiyun in the disaster, told AFP in an interview at his home in Beijing earlier this month that he remains set on finding answers, despite frustration with the authorities.
"Finding the plane, finding my loved one, and finding the truth, I believe this is something I must do in my life," he said.
MH370 search restarts more than ten years after plane's disappearance
Issued on: 30/12/2025 - FRANCE24
The deep-sea search for the wreckage of the MH370, which disappeared in 2014 is set to restart on December 30. Ocean Infinity, a private US and UK based company are managing the effort. They are working on a 'no find, no fee' contract, and will receive almost 60 million euros if they succeed. The hope is that improved technology will help solve the biggest recent mystery in aviation.
On Tuesday morning, a sudden storm swept over the coast of Croatia, tearing down trees and disrupting traffic - and sending a runaway ferry careening into a line of moored passenger vessels.
At the port of Split, Croatia, the ferry Petar Hektorovi? was tied up at the pier when the storm hit. In unexpectedly high winds, its lines parted, and it drifted into two vessels. First it made contact with a catamaran, then struck a tourist excursion vessel, which was damaged by the impact and sunk. No passengers were aboard and no personnel were injured, harbormaster Zvone Perkusic told local outlet tportal - adding that it could have been much worse. The crew of the Hektorovi? dropped both anchors and started the main engines quickly, averting further damage, operator Jadrolinija said.
"The ferry captain's ingenious and courageous maneuver should be commended, thanks to which a tragedy and much greater damage were avoided," Perkusic said.
First responders and a commercial salvage company attended the scene to control the risk of pollution.
The storm also injured at least three people on shore in Split, and was powerful enough to damage the roof of the city's soccer stadium. Further up the coast, in Barbariga, a waterspout was reported just offshore.
Separately, near the island of Kaprije, a small excursion catamaran capsized, and nine people - including seven Swedish nationals and one German - went over the side. Good Samaritans and police responders rescued all nine and brought them to shore, including two who were taken to a hospital for medical care.
Tuesday, June 03, 2025
NTSB: Overwhelming Towline Force Caused Loss of Towboat in Severe Storm
Towboat Baylor J. Tregre was overwhelmed by towline forces during a severe storm (Trinity Towing photo courtesy of NTSB)
The NTSB concluded that the loss of a towboat off the Louisiana coast in May 2024 was due to the vessel being overwhelmed during a sudden, severe storm. While the crew of the towing vessel Baylor J, Tregre was unable to maneuver in an attempt to save the vessel due to overwhelming towline force, the report also highlights the lack of an emergency release and some issues with the vessel that might have accelerated its loss.
The towboat, which was built in 1997 and 67 feet long, was towing a 260-foot long barge loaded with a production platform and helideck bound for an offshore site. They had departed Houma, Louisiana, but due to the height of the platform were required to sail offshore instead of the Gulf Intercoastal Waterway.
It was midday on May 13 with the vessel approximately 60 miles from its destination. The weather was good with 3 to 4-foot seas and wind of 9 to 13 knots. The crew had checked weather reports and was receiving information from its shoreside office. They had a report of possible thunderstorms. The tow was traveling and 4 to 5 knots.
The mate was navigating when he observed a storm forming and made changes to the course but the line of thunderstorms appeared to shift to a circle and the wind began to intensify “at a very quick rate.” It was possibly hailing but they never determined if a waterspout had formed. The captain and mate later estimated for investigators that the winds could have been 85 to 100 mph (74 to 87 knots).
The vessel was losing speed and had started to heel. The mate was attempting to reposition the vessel but as the situation quickly deteriorated the vessel was heeling at 45 degrees. They had lost sight of the barge in the storm but it had moved alongside the towboat with the crew later reporting the line was taught “like a banjo string.” The captain ordered the mate to turn the barge loose. He attempted but reported to the captain it was impossible. The NTSB highlights in the report that the vessel did not have an emergency release and none is required under the regulations. Even if the mate had been able to reach the controls in the doghouse, it required the winch engine to be running, which it was not.
The captain was attempting to change the heading but by then the port quarter of the towboat was underwater. They believed the starboard rudder and propeller were out of the water. They made a distress call and moments later the vessel lost electrical power and the engines stopped running. Seas were now 6 to 7 feet.
The crew had to climb out of the tilted wheelhouse and one deckhand fell into the water. The others had to follow as the vessel sank. The self-deploying liferaft worked and they were eventually able to make it to the raft. The emergency beacon was also located and the Coast Guard was able to rescue the four crewmembers, although one suffered minor injuries.
When the towboat was recovered, the NTSB reports some of the fiddley blowers on the second deck were missing and might have contributed to the flooding. Also, some of the sealing gaskets were found deteriorated on the exterior doors.
The casualty, which resulted in $2 million in damages, they attributed to the overwhelming towline forces during the storm and the inability to complete an emergency release of the barge. The heeling became unrecoverable for the vessel.
Saturday, April 05, 2025
Search for long-missing flight MH370 suspended: Malaysia minister
An event was held to mark the 10th year since the Malaysia Airlines flight MH370 disappeared from radar screens - Copyright AFP Arif Kartono
Raevathi SUPRAMANIAM
The latest search for Malaysia Airlines flight MH370 has been suspended, Kuala Lumpur’s transport minister said, more than a decade after the plane went missing.
“They have stopped the operation for the time being, they will resume the search at the end of this year,” Transport Minister Anthony Loke said in a voice recording sent to AFP on Thursday by his aide.
The Boeing 777 carrying 239 people disappeared from radar screens on March 8, 2014, while en route from Kuala Lumpur to Beijing.
Despite the largest search in aviation history, the plane has not been found.
Loke’s comments come just one month after authorities said the search had resumed, following earlier failed attempts that covered vast swaths of the Indian Ocean.
An initial Australia-led search covered 120,000 square kilometres (46,300 square miles) in the Indian Ocean over three years, but found hardly any trace of the plane other than a few pieces of debris.
Maritime exploration firm Ocean Infinity, based in Britain and the United States, led an unsuccessful hunt in 2018, before agreeing to launch a new search this year.
“Right now, it’s not the season,” Loke said in the recording, which was made during an event at Kuala Lumpur International Airport on Wednesday.
“Whether or not it will be found will be subject to the search, nobody can anticipate,” Loke said, referring to the wreckage of the plane.
– Aviation mystery –
The search was put on hold “due to seasonal weather changes and unavoidable prior commercial commitments”, a separate statement posted on the “MH370 Families” Facebook group said.
Loke said in December that a new 15,000 square kilometre area of the southern Indian Ocean would be scoured by Ocean Infinity.
The most recent mission was conducted on the same “no find, no fee” principle as Ocean Infinity’s previous search, with the government only paying out if the firm finds the aircraft.
The plane’s disappearance has long been the subject of theories — ranging from the credible to outlandish — including that veteran pilot Zaharie Ahmad Shah had gone rogue.
A final report into the tragedy released in 2018 pointed to failings by air traffic control and said the course of the plane was changed manually.
Two-thirds of the passengers were Chinese, while the others were from Malaysia, Indonesia, Australia, and elsewhere.
Relatives of passengers lost on the flight have continued to demand answers from Malaysian authorities.
Family members of Chinese passengers gathered in Beijing outside government offices and the Malaysian embassy last month on the 11th anniversary of the flight’s disappearance.
Attendees of the gathering shouted, “Give us back our loved ones!”
Some held placards asking, “When will the 11 years of waiting and torment end?”
From dissecting hearts to designing ornithopters, James Bell Pettigrew saw spirals as the blueprint of nature—but his grand vision was lost to history.
One halcyon spring day in 1903, the 69-year-old anatomist and naturalist Dr. James Bell Pettigrew sat at the top of a sloping street on the outskirts of St. Andrews, Scotland, perched inside a petrol-powered airplane of his own design. Over the course of 40 years, ever since he began his aeronautical experiments in London in 1864, Pettigrew had constructed dozens of working models of various flying apparatus.
From anatomical dissection and observations of animals in the wild and at the London Zoo, Pettigrew had come to conceive of all creatures—whether on land, in water, or the air—as propelling themselves by throwing their bodies into spiraling curves, such that their movements were akin to waves in fluid, or to waves of sound.
Pettigrew’s “Ornithopter”
Instead of driving the wings vertically as in other flying machines modeled on animal flight, Pettigrew’s “ornithopter” emulated the movement that he had discovered to be universal in flying creatures: rhythmic figure-of-eight curves. To permit this undulatory motion, Pettigrew had furnished the root of the wing with a ball-and-socket joint; to regulate the several movements of the vibratory wing—comprised of bamboo cane from which issued tapering rods of whalebone covered in a thin sheet of India rubber—he employed a cross-system of elastic bands. A two-stroke engine’s piston drove this elaborate apparatus of helical biological mimicry.
After a lengthy essay considering the antiquity of man—and once again stressing that the human physical form had altered not at all for at least some 10,000 years—he concluded:
Man is not in any sense the product of evolution. He is not compounded of an endless number of lower animal forms which merge into each other by inseparable gradations and modifications from the monera up to man. …
He is the highest of all living forms. The world was made for him and he for it … Everything was made to fit and dovetail into every other thing … There was moreover no accident or chance. On the contrary, there was forethought, prescience, and design.
Disagreements With Darwin
Across the three volumes, 1,416 pages, and nearly 2,000 illustrations that made up his magnum opus Design in Nature, Pettigrew barely mentioned Charles Darwin’s theory of natural selection, which he found “lame, halting, and impotent.” Though Pettigrew deeply admired the English naturalist—who had on more than one occasion (as had T. H. Huxley, Richard Owen, John Lubbock, St. George Mivart, and dozens of other leading men of science) visited Pettigrew at London’s Hunterian Museum of the Royal College of Surgeons of England to view his state-of-the-art anatomical and physiological preparations—Darwin seemed to Pettigrew only tentatively confident of the very theory he had proposed to explain Nature’s “endless forms most beautiful.”
He expected that, within a generation, few would recall Darwinism as anything other than a passing fancy. What Pettigrew could not excuse were the egregious errors in Darwin’s pronouncement about the spiraling motions of Clematis, Convolvulus, honeysuckle, hops, and many other plants. Whatever positive contributions the retiring naturalist had made with his research on twining plants were undermined by his inexact language and thinking. Pettigrew strenuously objected to Darwin’s use of the term “reflex action” for these plants’ behavior, since this was a phrase used for action in nervous systems—of which Clematis, Convolvulus, and their cousins possessed none.
A Lifelong Fascination With Spirals
By way of a few ingenious experiments—conducted back in 1865, after reading Darwin’s “On the Movements and Habits of Climbing Plants“—Pettigrew had utterly demolished its author’s “irritability theory” for the movement of the green chimeras. Just as with spiral teeth, claws, horns, muscles, and bones, spirally-turning plant tendrils were in no way the result of external contact. These whirling, twirling structures, as free of contact as the ocean-suspended spiraling egg cases of sharks and dogfish, danced to some wholly invisible music.
Pettigrew confessed himself totally spellbound by the mystery of Nature’s most ubiquitous, liquid, and quixotic form—the spiral. Though he had scrutinized this universal cipher from the macrocosmic spiral nebulae down to the dextro- and sinistro-helical microcosmic molecules of the periodic table, Pettigrew was left baffled by the question of its origin. The best that he could say was that the answer “by no means lies on the surface.”
Overwhelmed as he was by the world’s archetypal whorl, he was sure of one thing—these marvelous spiral arrangements could not be of purely physical origin. A reviewer of Pettigrew’s Lancet series on circulation in plants and animals declared that the distinguished anatomist was a “spiralist” who found that organs were not only constituted spirally, but that they functioned spirally too.
Putting Isaac Roberts’ astonishing 1888 photographs of the Great Nebula in Andromeda and other spiral nebulae to cosmic effect at his argument’s outset, Pettigrew then immersed the reader in a cascade of more humble spiral forms—the mineral prochlorite; ram’s horns; bacteria from the River Thames; fossil algae carpogonia; dozens of figures of spiral fronds, floral bracts, stems, leaves, tendrils, and seeds in plants.
Design in Nature’s plates of spirals in the animal world started with spermatozoa (of crayfish, rabbit, field mice, wood shrike, goldfinch, creeper, perch, frog, rat, and human) and ran up the great chain of being through: frog ganglia; dozens of species of Foraminifera; the exquisite Nautilus pompilius; Devonian, Silurian, Jurassic, Cretaceous, and contemporary shells; the horns of goats, gazelles, and antelope; the human cochlea; almost every section of the vertebrate skeleton, from the phalanges of the Indian elephant to the turbinated inner bones of the human skull. The human umbilical cord looked for all the world like a waterspout or the homely and helically aspiring English Hops, those twining stems of Darwin’s go-to research subject.
All these were pictured in the first 50 pages of the book; hundreds more images were liberally spread through the complete three volumes. At times, while reading Design in Nature, the spiral risks losing all significance, so promiscuously ubiquitous is its form.
The Human Heart: A Perfect Spiral Mystery
At the center of this dizzying array lay the sacred secret that had so profoundly occupied Aristotle and Aquinas, Leonardo and Vesalius—the human heart. The heart’s sevenfold spiral structure was the mystery of mysteries, its form preserving perfectly the sense of both its muscular contractions and the interior circulatory patterns of its blood. Pettigrew had himself discovered this as a young medical student at the University of Edinburgh; so impressed had his professor been by Pettigrew’s dissections that he invited him to deliver the prestigious Croonian lecture at the Royal Society of London in 1860.
The University of Edinburgh was, in Pettigrew’s medical student days, at the zenith of its reputation: James Syme was dazzling the world with his bold pioneering surgery; James Young Simpson had—with dinner guests at his own 52 Queen Street table—proved the safety of chloroform as an obstetric anesthetic; with his methodical use of the microscope, John Hughes Bennett inaugurated a new era in the teaching of clinical medicine; Joseph Lister’s careful application of carbolic acid (phenol) to wounds, dressings, and instruments—though mocked initially by his medical colleagues—had revolutionized the practice of surgery.
When Pettigrew reminisced that the rivalry among these stellar physicians had been “a case of diamond cut diamond,” he recognized their fame by employing a most apt metaphor. Cutting—with a varied repertoire of scalpels, lancets, and scissors—was the surgeon’s special art. Pettigrew’s tutor in the art was Professor of Anatomy John Goodsir, who, with his large, powerful, finely shaped hands never failed to wield the scalpel “with a dexterity and grace truly remarkable.”
Innovative Dissection Methods and the Gold Medal
At the end of the 1857–58 winter term, Professor Goodsir gave out as the subject for the senior anatomy gold medal: “The Arrangement of the Muscular Fibres in the Ventricles of the Vertebrate Heart.” This Gordian knot of anatomy had over the previous three centuries foiled the efforts of Vesalius, Albinus, Haller, and others to unravel it.
Back home, between sessions at his family’s country home in Lanarkshire, the 24-year-old Pettigrew at once proceeded to dissect in large numbers every kind of heart within reach, making careful drawings and notes of each. Beginning with sheep, calf, ox, and horse, he found that he had to devise a new mode of dissection that would allow both sufficient hardness to preserve the anatomical structures, and ample softness so as to tease out their multitudinous tissue layers.
Having exhausted a battery of methylated spirits and other chemicals, he hit upon the expedient of stuffing and gently distending the ventricles of the heart with a truly Scottish material—dry oatmeal. Slowly boiling the hearts for four to five hours, he could get rid of all the external fat, blood vessels, nerves, lymphatics, and cellular tissue.
A fortnight to three weeks hardening in a bath of methylated spirits followed, after which he was able to separate and peel off the muscular fibers of the ventricles as if they were layers of an onion. The layers were of two kinds: muscular fibers from the outside of the heart wound in a spiral direction from left to right, progressing downwards; the internal fibers ran in an opposite spiral direction from right to left, upwards.
In fact, the internal and external layers of the muscular fibers of each and every one of the more than 100 vertebrate hearts he had dissected formed two sets of opposite spirals which crossed each other, the crossings becoming more oblique towards the center. These inner and outer layers were further divided into a pair of left- and right-handed spiral sets. There was, especially in the left ventricle, a most perfect spiral symmetry, one that rivaled the Great Andromeda Nebula.
As gifted a model maker as he was a dissector, Pettigrew found this now-exposed double spiral heart to be an anatomical puzzle of the first order, for the external muscle fibers were seamlessly and spirally continuous with the internal muscle fibers at both the apex and base of the ventricles. One day Pettigrew came down to dinner a little earlier than usual, and, seeing a newspaper lying on the table, felt an impulse to roll it up obliquely from one corner—as grocers do in making conical paper bags.
To Pettigrew’s surprise, the lines of print on the layers of newspaper ran in different directions according to a graduated order: the lines on the outer layers ran spirally from left to right downwards, becoming more oblique as the central layer was reached; the lines of print on the inner layer ran spirally from right to left upwards, becoming more vertical as they moved away from the center. The newspaper print on the two layers crossed at widening angles, forming an X, as the center was approached.
The print was seamless at both base and apex of the paper cone, resembling the arrangement of muscle fibers in the heart. There were, in effect, a series of complicated figure-of-eight loops, arranged in a marvelously mathematical pattern of great complexity and beauty. “Here,” he wrote, “was the whole thing in a nutshell. It was a case of the reading turning in or involuting at the apex and of the reading turning out or evoluting at the base.” Pettigrew’s newspaper model showed that the heart’s double-helical structure—now known as the helical ventricular myocardial band (HVMB)—was essentially a triple-twisted Möbius strip.
Crying “Eureka!” Pettigrew ransacked the Lankarshire fish shops for the hearts of cod, salmon, sunfish, and turbot. He also lucked into securing the heart of a monster shark killed in the Firth of Forth. From the large hotels he collected several fine sea turtle hearts, as well as a land tortoise and an alligator. Raiding the poulterers too, he got the hearts of duck, goose, capercaillie, turkey, and one “splendid” swan’s heart.
From fish to frog to turtle, the muscular fiber arrangement—though interesting—shed no light on the complicated arrangement in the ventricles of bird and mammal. (The pattern in the bird exactly matched that of the mammal except that, in the right ventricle of the bird, a muscular valve took the place of the fibrous tricuspid valve of mammals.) In the small hours of the morning, in his humble student lodgings, Pettigrew worked away now at dissections of sheep, calf, ox, horse, deer, pig, porpoise, seal, lion, giraffe, camel, and human—112 dissections and associated drawings in all.
When the day for awarding the gold medal arrived, 400 students crowded the large anatomical theater to hear the altogether unknown Pettigrew’s name pronounced. Professor Goodsir asked Pettigrew to call on him the next day, anxious to win the heart dissection preparations for the University’s Anatomical Museum. The 112 neat glass jars can still be found there today.
He also invited young Pettigrew to report on his discoveries to the Royal Society of London; Pettigrew delivered his address, “On the Arrangement of the Muscular Fibres in the Ventricles of the Vertebrate Heart,” to the Royal Society the very same week that Origin of Species was published by John Murray of Albemarle Street, a short walk from the Royal Society lecture hall. That anyone might attribute such an ingeniously crafted organ as the mammalian heart to mere chance, Pettigrew believed, was sheer madness.
The Spiral in Animal Locomotion
Nature’s variegated spiral structures, with the mammalian heart always for him the epitome, represented but one panel of the triptych that Pettigrew would go on to assemble over the next half century. Volume Two of Design in Nature is devoted solely to spiral movement in circulation (although the circulation section dealt with both plant and lower animal circulatory systems, three-quarters of this study focused on mammals and man); Volume Three to the spiral as locomotion’s characteristic form.
In both arenas of animal physiology, Pettigrew found a spectacular resonance: movement at once precedes and follows structure, the direction of movement in living things being in every instance determined by the composition and configuration of kinetic spiral parts. This resonance seemed to reach right down to the atomic level. Unlike the closed system of the heart, the spiraling lines of atoms and molecules were arranged so that matter could be added in any amount, in unlimited directions. An open flow of energy and form was the basis for growth and progression in all creatures.
Reflected in the vertebrate skeleton, this open attitude also made graceful locomotion possible. Pettigrew quoted his mentor John Goodsir: “The peculiar spiral attitudes into which the human body can be thrown are explained by the spiral curve of the vertebral articular surfaces, and the spiral arrangement of the muscles. No mammal can throw its trunk into those spiral curves which subserve the balance of the human frame and confer the peculiar grace and expression of its movements.”
Only birds—especially his beloved swallows and swifts, which darted round the turrets of Swallowgate, the stone residence that Pettigrew had built at St. Andrews, and across the broad moor leading to the nearby sea cliffs—could rival the poetry of motion executed by the human body, their movements freed in the less resistant medium of air.
The earthbound human body’s idiosyncratic spiraling structure liberated the hands to sculpt clay, tie rope, and grasp chalk, paintbrush, and scalpel in order to go inside the organs of Life and then represent them in color and line. Bony spirals hidden beneath spiral muscles flexed and extended to skip, leap, creep, crawl, wriggle, tumble, skate, march, flip, prance, moonwalk. The polka-ing, pirouette-ing, schottish-ing, waltzing, two-stepping human danced upon a near infinity of corporeal eddies.
When Pettigrew took up the third strand of his argument from design, he began again with structures—the muscular and osseous systems, which he found intimately complimentary. Skeletal plates suggest that each part of our bony frame was but a partial realization of the sort of spiral geometry Pettigrew had discovered in the heart. The halfway twisting femur, humerus, tibia, fibula, ulna, and radius reached their fully spiral apotheosis in clavicle, pelvis, and scapula—each of which approached once again the geometry of the Möbius strip.
The Forgotten Legacy of Design in Nature
Published posthumously, just months before the centennial of Darwin’s birth, and the fiftieth anniversary of On the Origin of Species—celebrations which Darwinians fully exploited to advance a false picture of Darwin as a rabid opponent of teleology—Design in Nature dropped from sight as rapidly as Pettigrew’s ornithopter dropped from the sky over the St. Andrews moorland. The journal Nature’s full-page review savaged the work’s teleological argument, wanly submitting that had Pettigrew lived to complete the editing of his opus, he would have “expunged or modified” its conclusions.
Biostatistician Raymond Pearl was less generous, calling “the ponderous work” “probably the most extensive and serious single contribution to humorous literature which has appeared in recent years,” and declaring Pettigrew’s “spiral philosophy”—that “the Creator fashioned men and corkscrews on the same plan”—as “medieval as any cathedral.” Not a single work of contemporary biology or natural history—including D’Arcy Wentworth Thompson’s On Growth and Form (1917), which devoted considerable discussion to spiral forms—cited Design in Nature.
A century on from its publication, however, Design in Nature holds up not only as an unsurpassed survey of biological form, but as a provocative modern inquiry into the causation of form. Pettigrew’s magnum opus is also a phenomenological masterpiece whose lively prose and gorgeous illustrations might serve to inspire a new generation of “spiralists.”
About the author: Dr. Kevin Dann is a historian, naturalist, and troubadour. His books include Enchanted New York: A Journey Along Broadway Through Manhattan’s Magical Past (NYU Press, 2020) and Expect Great Things: The Life and Search of Henry David Thoreau (TarcherPerigree, 2017). Dann has taught at Rutgers University, the University of Vermont, and the State University of New York and leads bike tours in New York City. Find him online at: www.drdann.com.
Source: This article was originally published on The Public Domain Review under a Creative Commons Attribution-ShareAlike 3.0. If you wish to reuse it please see: https://publicdomainreview.org/reusing-material/. This version was produced for the Observatory by Earth | Food | Life, a project of the Independent Media Institute.
How chemistry and force etch mysterious spiral patterns on solid surfaces
Hundreds of regular patterns spontaneously form on a small germanium chip
Curiosity about a mistake that left tiny dots on a germanium wafer with evaporated metal films led to the discovery of beautiful spiral patterns etched on the surface of the semiconductor by a chemical reaction.
Further experiments showed that the patterns arise from chemical reactions that are coupled to mechanical forces through the deformation of a catalyzing agent.
The new system is the first major advance in experimental methods to study chemical pattern formation since the 1950s. Studying these complex systems will help scientists understand other natural processes, from crack formation in materials to how stress influences biological growth.
UCLA doctoral student Yilin Wong noticed that some tiny dots had appeared on one of her samples, which had been accidentally left out overnight. The layered sample consisted of a germanium wafer topped with evaporated metal films in contact with a drop of water. On a whim, she looked at the dots under a microscope and couldn’t believe her eyes. Beautiful spiral patterns had been etched into the germanium surface by a chemical reaction.
Wong’s curiosity led her on a journey to discover what no one had seen before: Hundreds of near-identical spiral patterns spontaneously can form on a centimeter square germanium chip. What’s more, small changes in experiment parameters, such as the thickness of the metal film, generated different patterns, including Archimedean spirals, logarithmic spirals, lotus flower shapes, radially symmetric patterns and more.
The discovery, published in Physical Review Materials, occurred fortuitously when Wong made a small mistake while attempting to bind DNA to the metal film.
“I was trying to develop a measurement technique to categorize biomolecules on a surface through breaking and reforming of the chemical bonds,” Wong said. “Fixing DNA molecules on a solid substrate is pretty common. I guess nobody who made the same mistake I did happened to look under the microscope.”
To learn more about how the patterns formed, Wong and co-author Giovanni Zocchi, a UCLA physics professor, investigated a system that involved evaporating a 10-nanometer thick layer of chromium on the surface of a germanium wafer, followed by a 4-nanometer layer of gold. Next, the researchers placed a drop of mild etching solution onto the surface and dried it overnight, then washed and re-incubated the chip with the same etching solution in a wet chamber to prevent evaporation.
“The system basically forms an electrolytic capacitor,” Zocchi said.
Over the course of 24-48 hours, a chemical reaction catalyzed by the metal film etched remarkable patterns on the germanium surface. Investigation of the process revealed that the chromium and gold films were under stress and had delaminated from the germanium as the catalytic reaction proceeded. The resulting stress created wrinkles in the metal film that, under further catalysis, etched the amazing patterns the researchers had seen.
“The thickness of the metal layer, the initial state of mechanical stress of the sample, and the composition of the etching solution all play a role in determining the type of pattern that develops,” Zocchi said.
One of the most exciting findings in this study is that the patterns are not purely chemical but are influenced by residual stress in the metal film. The research suggests that the metal’s preexisting tension or compression determines the shapes that emerge. Thus, two processes, one chemical and one mechanical, worked together to yield the patterns.
This type of coupling, formed between catalysis-driven deformations of an interface and the underlying chemical reactions, is unusual in laboratory experiments but common in nature. Enzymes catalyze growth in nature, which deforms cells and tissue. It’s this mechanical instability that makes tissue grow into particular shapes, some of which resemble the ones seen in Wong’s experiments.
“In the biological world, this kind of coupling is actually ubiquitous,” Zocchi said. “We just don’t think of it in laboratory experiments because most laboratory experiments about pattern formation are done in liquids. That’s what makes this discovery so exciting. It gives us a non-living laboratory system in which to study this kind of coupling and its incredible pattern-forming ability.”
The study of pattern formation in chemical reactions began in 1951 when the Soviet chemist Boris Belousov accidentally discovered a chemical system that could spontaneously oscillate in time, which inaugurated the new fields of chemical pattern formation and nonequilibrium thermodynamics. At the same time and independently, the British mathematician Alan Turing discovered that chemical systems, later termed “reaction-diffusion systems,” could spontaneously form patterns in space, such as stripes or polka dots. The reaction-diffusion dynamics observed in Wong’s experiments mirrored the theoretical ones posited by Turing.
Although the field of complex systems in physics and pattern formation enjoyed a time in the spotlight during the 1980s and 90s, to this day, the experimental systems used to study chemical pattern formation in the laboratory are essentially variants of ones introduced in the 1950s. The Wong-Zocchi system represents a major advance in the experimental study of chemical pattern formation.
