Science and technology

  • Digital immortality

    Difference Engine: Facebook for the dead

    by N.V. | LOS ANGELES

    THE only sure things in life, we are told, are death and taxes. Do not be unnecessarily depressed, because it is not actually true. Many citizens avoid paying taxes legitimately. And while no living creature has ever cheated death, there is a tiny jellyfish that comes close.

    First discovered in the Mediterranean in the late 19th century, Turritopsis dohrnii is believed to be the only species capable of aging backwards—reverting, in dire circumstances, from a mature adult medusa to an infant polyp. Theoretically, it can do so over and over again, effectively rendering itself biologically immortal. Unfortunately, no evidence has been found, in the laboratory or in the wild, to prove T. dohrnii has ever managed that trick.

    For good reason, evolution has engineered a finite limit into life's span. Staying alive is expensive, using resources that might otherwise be devoted to reproduction. The weakness of old age, and a maximum term of life, are the compromises natural selection has engineered between the two.

    It was once thought that the cells of at least vertebrates could carry on dividing indefinitely—in short, that they were immortal. Now scientists know that such immortality is the prerogative only of cancer cells. Healthy cells eventually hit the so-called “Hayflick limit”. At that point, their nuclei cease dividing, senescence commences, and the hereafter beckons. That is what aging is all about.

    The limiting factor gets its name from an experiment done in the 1960s by Leonard Hayflick, of the Wistar Institute in Philadelphia, who demonstrated that human fetal cells divide between 40 and 60 times and then enter a phase of senescence, during which division eventually grinds to a halt.

    A later discovery showed that each cell division shortens the length of the telomeres—small, disposable segments of DNA at the ends of a cell's chromosomes. The telomeres act as caps that stop chromosomes deteriorating, or fusing with other chromosomes to cause abnormalities. After repeated divisions, these caps become depleted, and the cell can no longer divide, having reached its Hayflick limit. At that point, the cell enters senescence and eventually self-destructs.

    Can the process be reversed? Experiments with mice and earthworms show it is possible to switch on the enzyme (telomerase) that produces telomeres—and thereby lengthen the chromosome's life-limiting caps. But while the change in telomere length is associated with the speed at which senescence progresses, no-one knows for sure whether it is a consequence of aging or the cause of it.

    For the foreseeable future, then, biological immortality—through medical intervention or genetic engineering—seems highly unlikely. Even if it were possible to arrest the process of aging, let alone reverse it, that still would not guarantee immortality. People would continue to die of trauma and disease.

    Following his own recent brushes with a couple of life-threatening conditions, your correspondent has become morbidly fascinated with the hereafter—and how, in particular, to communicate with the living from beyond the grave. Inevitably, science fiction offers some of the boldest ideas. In “Neuromancer”, William Gibson's 1984 mind-bender classic, the deceased character the story revolves around had, before dying, saved the contents of his mind to a read-only memory chip, which the protagonists must steal and decode to complete their mission.

    But writers of science fiction are not the only ones to explore the idea of uploading human consciousness to a computer. The notion has fascinated artificial-intelligence experts like Hans Moravec and Ray Kurzweil for years. Both have written extensively about the possibility of people being able to live indefinitely in a virtual world.

    Clearly, multimedia and the internet can be harnessed to enhance the way people, at least, communicate about the dead via inscriptions, obituaries, memorials, requiems or memento mori. Indeed, the earliest applications of multimedia for remembrance were the post-mortem daguerreotypes used by grieving Victorians as mementos of their dear departed.

    Today, tributes set up on websites by families and friends of a deceased have become commonplace. Some are simple HTML pages with details of the dead person and perhaps a picture or two. Others include slide shows, video and music as well as a narrative and timeline, uploaded along with tributes from family and friends. Numerous websites now offer professional services to make it easier for the bereaved to create an online presence for a departed relative.

  • Facebook

    Sharing it all




  • Neutrinos

    There was a neutrino named Bright

    by J.P.

    Who travelled faster than light


  • Rocketry

    Bigger than Saturn, at last

    by T.C.



  • Dancing robots

    Invitation to the dance

    by The Economist online | NEW YORK

    AS THE violins soar, a lone dancer lopes gracefully across the stage of the Joyce Theatre in New York. But this is no solo. Two UFOs playfully chase him and swoop through the air around him. Modern dance and robotics may seem an unlikely combination, but this summer a troupe called Pilobolus has been performing a routine called “Seraph” with the assistance of these special guests—aerial robots programmed by the Massachusetts Institute of Technology (MIT). 

    Pilobolus is known for dances that incorporate unusual elements. Few, though, have been stranger than the two four-rotored helicopters that accompanied Matt Del Rosario on the stage of the Joyce.

  • Social networking

    A nightclub on your smartphone

    by L.S.

    A BIG fridge full of drinks, comfy chairs, even a Jacuzzi—Badoo's new digs in a top floor office in Soho in central London feel as if the firm is trying too hard to resemble a Silicon Valley start-up. Yet when it comes to business, Badoo is certainly no wannabe. It has a shot at becoming one of Europe's leading internet firms.

    What makes the firm so promising is that it seems to have discovered a new “space”, as digital cognoscenti call a big new market. If social networks such as Facebook are about keeping in touch with friends, and online-dating sites about finding a long-term relationship, Badoo is about something in between: meeting people spontaneously. Some call it “nightclub-as-a-service”. 

    When users sign up, they upload photos of themselves and provide such details as age, sex and interests. Other users can discover them based on this information as well as by browsing the photos. Originally the service was only available on the web, but the firm now also offers applications on Facebook and for smartphones. The mobile application, for instance, lets users adjust how widely they fancy casting their net. If they set the dial to one mile, say, and find somebody they would like to meet, they can strike up an online chat and then get together.

  • Reliability of the grid

    Difference Engine: Disaster waiting to happen

    by N.V. | LOS ANGELES









  • Science in Vietnam

    Stemming the outflow of talent

    by H.C. | HANOI

    LAST month Vietnam placed third at Robocon, an Asia-Pacific robot-building competition for university students. With rivals like the famously tech-savvy Japan and Korea, coming third in a 19-strong field may sound like a sterling achievement. In fact, it was a poor showing. Vietnam has won the event three times in the past ten years (in 2002, 2004 and 2006).

    Though the nation excels at international contest it fares less well in day-to-day work. Much of that winning talent goes to waste (or abroad) for lack of resources. The new-ish science and technology minister, Nguyen Quan, hopes to change this.

  • Frugal innovation

    Wholly shit

    by A.A.K. | MUMBAI

    IN THE comedy film "Ace Ventura: When Nature Calls" the title character, a pet detective played by Jim Carrey, extolls guano as “an essential ingredient for the production of 84% of the world's organic fertilizer, a $1.4 billion industry.” Although the numbers do not quite add up, the benefits of animal waste cannot be overestimated. Records dating back to 1850BC suggest that Egyptian women used crocodile excrement as a spermicide. Tanneries in the Victorian era exploited the flammability of pigeon droppings and dog feces to soften animal hide, a prerequisite for making fine leather. During the 1940s German troops in North Africa experimented with camel dung to cure dysentery. Today, Indonesia is home to Kopi Luwak, the world's most expensive coffee extracted from palm-civet droppings, and in Bolivia, llamas' alkaline dung helps treat toxic water leaking from abandoned silver and tin mines. 

    It does not, then, come as a surprise that Mahima Mehra, a Delhi-based paper merchant, turned to elephant dung as a raw material. Ms Mehra sells paper, produced by her business partner Vijayendra Shekhawat, under the name Haathi Chaap, Hindi for "Elephant Mark". They stumbled on the idea during their visit to Amer fort in Jaipur. They observed that the clumps of roughage left behind by elephants ferrying tourists up to the fort bore a striking similarity to the raw fibre used in paper-making. 

    The idea is not wholly new. Paper producers in Sri Lanka, Thailand, Malaysia, and even America have employed pachyderm poop to the same effect. Unable to chew, elephants consume food in large gulps. The salivary glands act as a lubricant which softens the coarse fare and aids digestion. But like all heavy non-ruminating mammals, they have trouble digesting cellulose, an organic compound which constitutes a third of all plant matter. Bacterial fermentation helps to break cellulose down in the digestive tract, but of pachyderms' average daily intake of 150kg or so of plant matter, about 60% passes right through.

    Sure enough, Mr Shekhawat discovered that the resulting, fibre-rich dung is ideal for manufacturing paper. The elaborate production process begins literally in his own backyard where, one morning each week, he dumps a truckload of dung collected from the roadside. His family removes foreign objects like chocolate wrappers and cigarette foils. The dung is then washed thoroughly for about two hours in a large container. What remains is wet straw. (The washing water, which seeps into the soil, acts as a good fertiliser.) Next, the soggy substance is boiled for a couple of hours to disinfect it. (Hydrogen peroxide or caustic soda can also be used to kill bacteria, but it pollutes the water and harms plants, says Ms Mehra.)

  • Traffic management

    APPlied logic

    by The Economist online



  • Contraceptives and cervical cancer

    Hidden benefits

    by C.H. | NEW YORK

    CERVICAL cancer is usually caused by a viral infection. Two particular strains of the human papilloma virus (HPV) are responsible for 70% of such cancers. They do so by turning off genes that would otherwise suppress the formation of tumours. HPV infections do not, however, necessarily lead to cervical cancer—the best estimate is that less than 1% do. And a paper just published in the Lancet Oncology by Xavier Castellsagué of the Catalan Institute of Oncology, in L'Hospitalet de Llobregat, Spain, and his colleagues suggests a way even that figure might be reduced.

  • Medical technology

    Crowdsourcing good Samaritans

    by M.H. | SEATTLE



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