Tag Archives: life

BigBang

Tantalizing Enceladus

Fountains_of_Enceladus

Sorry, Moon but my favorite satellite doesn’t even orbit the Earth.

Enceladus is my favorite moon, despite its diminutive size — its diameter is only around 500 km. It circles Saturn and while it only ranks as the ringed planet’s sixth largest moon, it is perhaps the most fascinating.

A decade of images courtesy of the Cassini spacecraft and the Hubble Space Telescope show amazing  plumes of icy material spouting from one or more underground sources. To date, astronomers and planetary scientists have catalogued over 90 geyser-like jets on the surface of Enceladus.

More recently, a couple of year’s ago, NASA’s researchers confirmed the presence of a vast subsurface ocean of liquid water beneath Enceladus’ icy crust. Scientists believe this ocean powers its many geysers or cryovolcanoes. Moreover, the many geysers spew a particle cocktail of ices and organic compounds. It is this mixture of liquid water and organic chemistry that has many scientists agog — pondering the possibility of life beyond the shores of our home planet.

Catch the latest on the search for possible signs of life on Enceladus from Scientific American, here.

Image: Fountains of Enceladus. Recent Cassini images of Saturn’s moon Enceladus backlit by the sun show the fountain-like sources of the fine spray of material that towers over the south polar region. Courtesy: NASA/JPL/Space Science Institute. Public Domain.

 

Art, Idea Soup

Steps of Life

Steps-of-life-19th-century-print

Are you adolescent or middle-aged? Are you on life’s upwardly mobile journey towards the peak years (whatever these may be) or are you spiraling downwards in terminal decline?

The stages of life — from childhood to death — may be the simplistic invention of ancient scholars who sought a way to classify and explain the human condition, but over hundreds of years authors and artists have continued to be drawn to the subject. Our contemporary demographers and market researchers are just the latest in a long line of those who seek to explain, and now monetize, particular groups by age.

So, if you’re fascinated by this somewhat arbitrary chronological classification system the Public Domain Review has a treat. They’ve assembled a fine collection of images from the last five hundred years that depict the different ages of man and woman.

A common representation is to show ages ascending a series of steps from infancy to a peak and then descending towards old-age, senility and death. The image above is a particularly wonderful example of the genre and while the ages are noted in French the categories are not difficult to decipher:

20 years: “Jeunesse”

40 years: “Age de discretion”

50 years: “Age de Maturité”

90 years: “Age de decrépitude”

Image: “Le cours de la vie de l’homme dans ses différents âges”. Early 19th-century print showing stages of life at ten year intervals from 10-90 years as ascending and then descending steps. Courtesy: Wikipedia. Public Domain.

Idea Soup

Time for the Bucket List to Kick the Bucket

For the same reasons that New Year’s resolutions are daft, it’s time to ditch the bucket list. Columnist Steven Thrasher rightly argues that your actions to get something done or try something new should be driven by your gusto for life — passion, curiosity, wonder, joy — rather than dictated by a check box because you’re one step closer to death. Signs that it’s time to ditch the bucket list: when the idea is co-opted by corporations, advertisers and Hollywood; when motivational posters appear in hallways; and when physical bucket list buckets and notepads go on sale at Pottery Barn or Walmart.

From the Guardian:

Before each one of us dies, let’s wipe the “bucket list” from our collective vocabulary.

I hate the term “the bucket list.” The phrase, a list of things one wants to do in life before one dies or “kicks the bucket”, is the kind of hackneyed, cliche, stupid and insipid term only we Americans can come up with.

Even worse, “the bucket list” has become an excuse for people to couch things they actually desire to try doing as only socially acceptable if framed in the face of their death. It’s as if pleasure, curiosity and fun weren’t reasons enough for action.

If you want to try doing something others might find strange or unorthodox – write a novel, learn to tap dance, engage in a rim job, field dress a deer, climb Everest, go out in drag for a night – why do you need any justification at all? And certainly, why would you need an explanation that is only justifiable in terms of kicking the bucket?

According to the Wall Street Journal, the phrase “bucket list” comes to us from the banal mind of screenwriter Justin Zackham, who developed a list of things he wanted to do before he died. Years later, his “bucket list” became the title of his corny 2007 film starring Jack Nicholson and Morgan Freeman. It’s about two old men with terminal cancer who want to live it up before they die. That, if anyone at all, is who should be using the term “bucket list”. They want to do something with the finite time they know they have left? Fine.

But bucket list has trickled down to everday use by the perfectly healthy, the exceptionally young, and most of all, to douche bags. I realized this at Burning Man last week. Often, when I asked exceptionally boring people what had drawn them to Black Rock City, they’d say: “It was on my bucket list!”

Really? You wanted to schlep out to the desert and face freezing lows, scorching highs and soul crushing techno simply because you’re going to die someday?

There’s a funny dynamic sometimes when I go on a long trip while I’m out of work. When I backpacked through Asia and Europe in 2013, people (usually friends chained to a spouse, children and a mortgage) would sometimes awkwardly say to me: “Well, it will be the trip of a lifetime!” It was a good trip, but just one of many great journeys I’ve taken in my life so far. My adventures might interrupt someone else’s idea of what’s “normal.” But travel isn’t something I do to fulfil my “bucket list”; travel is a way of life for me. I do not rush into a trip thinking: “Good Christ, I could die tomorrow!” I don’t travel in place of the stable job or partner or kids I may or may not ever have. I do it as often as I can because it brings me joy.

Read the entire column here.

Idea Soup

Aspirational or Inspirational?

Both of my parents came from a background of chronic poverty and limited educational opportunity. They eventually overcame these constraints through a combination of hard work, persistence and passion. They instilled these traits in me, and somehow they did so in a way that fostered a belief in a well-balanced life containing both work and leisure.

But to many, especially in the United States, the live-to-work ethic thrives. This condition is so acute and prevalent that most Americans caught in corporate jobs never take their full — and yet meager by global standards — allotment of annual vacation. Our culture is replete with tales of driven, aspirational parents — think dragon mom — who seem to have their kid’s lives mapped out from the crib.

I have to agree with columnist George Monbiot: while naked ambition may gain our children monetary riches and a higher rung on the corporate ladder it does not a life make.

From the Guardian:

Perhaps because the alternative is too hideous to contemplate, we persuade ourselves that those who wield power know what they are doing. The belief in a guiding intelligence is hard to shake.

We know that our conditions of life are deteriorating. Most young people have little prospect of owning a home, or even of renting a decent one. Interesting jobs are sliced up, through digital Taylorism, into portions of meaningless drudgery. The natural world, whose wonders enhance our lives, and upon which our survival depends, is being rubbed out with horrible speed. Those to whom we look for guardianship, in government and among the economic elite, do not arrest this decline, they accelerate it.

The political system that delivers these outcomes is sustained by aspiration: the faith that if we try hard enough we could join the elite, even as living standards decline and social immobility becomes set almost in stone. But to what are we aspiring? A life that is better than our own, or worse?

Last week a note from an analyst at Barclays’ Global Power and Utilities group in New York was leaked. It addressed students about to begin a summer internship, and offered a glimpse of the toxic culture into which they are inducted.

“I wanted to introduce you to the 10 Power Commandments … For nine weeks you will live and die by these … We expect you to be the last ones to leave every night, no matter what … I recommend bringing a pillow to the office. It makes sleeping under your desk a lot more comfortable … the internship really is a nine-week commitment at the desk … an intern asked our staffer for a weekend off for a family reunion – he was told he could go. He was also asked to hand in his BlackBerry and pack up his desk … Play time is over and it’s time to buckle up.”

Play time is over, but did it ever begin? If these students have the kind of parents featured in the Financial Times last month, perhaps not. The article marked a new form of employment: the nursery consultant. These people, who charge from £290 an hour, must find a nursery that will put their clients’ toddlers on the right track to an elite university.

They spoke of parents who had already decided that their six-month-old son would go to Cambridge then Deutsche Bank, or whose two-year-old daughter “had a tutor for two afternoons a week (to keep on top of maths and literacy) as well as weekly phonics and reading classes, drama, piano, beginner French and swimming. They were considering adding Mandarin and Spanish. ‘The little girl was so exhausted and on edge she was terrified of opening her mouth.’”

In New York, playdate coaches charging $450 an hour train small children in the social skills that might help secure their admission to the most prestigious private schools. They are taught to hide traits that could suggest they’re on the autistic spectrum, which might reduce their chances of selection.

From infancy to employment, this is a life-denying, love-denying mindset, informed not by joy or contentment, but by an ambition that is both desperate and pointless, for it cannot compensate for what it displaces: childhood, family life, the joys of summer, meaningful and productive work, a sense of arrival, living in the moment. For the sake of this toxic culture, the economy is repurposed, the social contract is rewritten, the elite is released from tax, regulation and the other restraints imposed by democracy.

Where the elite goes, we are induced to follow. As if the assessment regimes were too lax in UK primary schools, last year the education secretary announced a new test for four-year-olds. A primary school in Cambridge has just taken the obvious next step: it is now streaming four-year-olds into classes according to perceived ability. The education and adoption bill, announced in the Queen’s speech, will turn the screw even tighter. Will this help children, or hurt them?

Read the entire column here.

BigBang

Active SETI

google-search-aliens

Seventy years after the SETI (Search for Extra-Terrestrial Intelligence) experiment began some astronomers are thinking of SETI 2.0 or active SETI. Rather than just passively listening for alien-made signals emanating from the far distant exoplanets these astronomers wish to take the work a bold step further. They’re planning to transmit messages in the hope that someone or something will be listening. And that has opponents of the plan rather worried. If somethings do hear us, will they come looking, and if so, then what? Will the process result in a real-life The Day the Earth Stood Still or Alien? And, more importantly, will they all look astonishingly Hollywood-like?

From BBC:

Scientists at a US conference have said it is time to try actively to contact intelligent life on other worlds.

Researchers involved in the search for extra-terrestrial life are considering what the message from Earth should be.

The call was made by the Search for Extra Terrestrial Intelligence institute at a meeting of the American Association for the Advancement of Science in San Jose.

But others argued that making our presence known might be dangerous.

Researchers at the Seti institute have been listening for signals from outer space for more than 30 years using radio telescope facilities in the US. So far there has been no sign of ET.

The organisation’s director, Dr Seth Shostak, told attendees to the AAAS meeting that it was now time to step up the search.

“Some of us at the institute are interested in ‘active Seti’, not just listening but broadcasting something to some nearby stars because maybe there is some chance that if you wake somebody up you’ll get a response,” he told BBC News.

The concerns are obvious, but sitting in his office at the institute in Mountain View, California, in the heart of Silicon Valley, he expresses them with characteristic, impish glee.

Game over?

“A lot of people are against active Seti because it is dangerous. It is like shouting in the jungle. You don’t know what is out there; you better not do it. If you incite the aliens to obliterate the planet, you wouldn’t want that on your tombstone, right?”

I couldn’t argue with that. But initially, I could scarcely believe I was having this conversation at a serious research institute rather than at a science fiction convention. The sci-fi feel of our talk was underlined by the toy figures of bug-eyed aliens that cheerfully decorate the office.

But Dr Shostak is a credible and popular figure and has been invited to present his arguments.

Leading astronomers, anthropologists and social scientists will gather at his institute after the AAAS meeting for a symposium to flesh out plans for a proposal for active Seti to put to the public and politicians.

High on the agenda is whether such a move would, as he put it so starkly, lead to the “obliteration” of the planet.

“I don’t see why the aliens would have any incentive to do that,” Dr Shostak tells me.

“Beyond that, we have been telling them willy-nilly that we are here for 70 years now. They are not very interesting messages but the early TV broadcasts, the early radio, the radar from the Second World War – all that has leaked off the Earth.

“Any society that could come here and ruin our whole day by incinerating the planet already knows we are here.”

Read the entire article here.

Image courtesy of Google Search.

BigBang

A Physics Based Theory of Life

Carnot_heat_engine

Those who subscribe to the non-creationist theory of the origins of life tend gravitate towards the idea of assembly of self-replicating, organic molecules in our primeval oceans — the so-called primordial soup theory. Recently however, professor Jeremy England of MIT has proposed a thermodynamic explanation, which posits that inorganic matter tends to organize — under the right conditions — in a way that enables it to dissipate increasing amounts of energy. This is one of the fundamental attributes of living organisms.

Could we be the product of the Second Law of Thermodynamics, nothing more than the expression of increasing entropy?

Read more of this fascinating new hypothesis below or check out England’s paper on the Statistical Physics of Self-replication.

From Quanta:

Why does life exist?

Popular hypotheses credit a primordial soup, a bolt of lightning and a colossal stroke of luck. But if a provocative new theory is correct, luck may have little to do with it. Instead, according to the physicist proposing the idea, the origin and subsequent evolution of life follow from the fundamental laws of nature and “should be as unsurprising as rocks rolling downhill.”

From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat. Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.

“You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant,” England said.

England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations. “I am certainly not saying that Darwinian ideas are wrong,” he explained. “On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.”

His idea, detailed in a recent paper and further elaborated in a talk he is delivering at universities around the world, has sparked controversy among his colleagues, who see it as either tenuous or a potential breakthrough, or both.

England has taken “a very brave and very important step,” said Alexander Grosberg, a professor of physics at New York University who has followed England’s work since its early stages. The “big hope” is that he has identified the underlying physical principle driving the origin and evolution of life, Grosberg said.

“Jeremy is just about the brightest young scientist I ever came across,” said Attila Szabo, a biophysicist in the Laboratory of Chemical Physics at the National Institutes of Health who corresponded with England about his theory after meeting him at a conference. “I was struck by the originality of the ideas.”

Others, such as Eugene Shakhnovich, a professor of chemistry, chemical biology and biophysics at Harvard University, are not convinced. “Jeremy’s ideas are interesting and potentially promising, but at this point are extremely speculative, especially as applied to life phenomena,” Shakhnovich said.

England’s theoretical results are generally considered valid. It is his interpretation — that his formula represents the driving force behind a class of phenomena in nature that includes life — that remains unproven. But already, there are ideas about how to test that interpretation in the lab.

“He’s trying something radically different,” said Mara Prentiss, a professor of physics at Harvard who is contemplating such an experiment after learning about England’s work. “As an organizing lens, I think he has a fabulous idea. Right or wrong, it’s going to be very much worth the investigation.”

At the heart of England’s idea is the second law of thermodynamics, also known as the law of increasing entropy or the “arrow of time.” Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble; in short, energy tends to disperse or spread out as time progresses. Entropy is a measure of this tendency, quantifying how dispersed the energy is among the particles in a system, and how diffuse those particles are throughout space. It increases as a simple matter of probability: There are more ways for energy to be spread out than for it to be concentrated. Thus, as particles in a system move around and interact, they will, through sheer chance, tend to adopt configurations in which the energy is spread out. Eventually, the system arrives at a state of maximum entropy called “thermodynamic equilibrium,” in which energy is uniformly distributed. A cup of coffee and the room it sits in become the same temperature, for example. As long as the cup and the room are left alone, this process is irreversible. The coffee never spontaneously heats up again because the odds are overwhelmingly stacked against so much of the room’s energy randomly concentrating in its atoms.

Although entropy must increase over time in an isolated or “closed” system, an “open” system can keep its entropy low — that is, divide energy unevenly among its atoms — by greatly increasing the entropy of its surroundings. In his influential 1944 monograph “What Is Life?” the eminent quantum physicist Erwin Schrödinger argued that this is what living things must do. A plant, for example, absorbs extremely energetic sunlight, uses it to build sugars, and ejects infrared light, a much less concentrated form of energy. The overall entropy of the universe increases during photosynthesis as the sunlight dissipates, even as the plant prevents itself from decaying by maintaining an orderly internal structure.

Life does not violate the second law of thermodynamics, but until recently, physicists were unable to use thermodynamics to explain why it should arise in the first place. In Schrödinger’s day, they could solve the equations of thermodynamics only for closed systems in equilibrium. In the 1960s, the Belgian physicist Ilya Prigogine made progress on predicting the behavior of open systems weakly driven by external energy sources (for which he won the 1977 Nobel Prize in chemistry). But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted.

Read the entire story here.

Image: Carnot engine diagram, where an amount of heat QH flows from a high temperature TH furnace through the fluid of the “working body” (working substance) and the remaining heat QC flows into the cold sink TC, thus forcing the working substance to do mechanical work W on the surroundings, via cycles of contractions and expansions. Courtesy of Wikipedia.

 

BigBang

Syndrome X

DNA_Structure

The quest for immortality or even great longevity has probably led humans since they first became self-aware. Entire cultural movements and industries are founded on the desire to enhance and extend our lives. Genetic research, of course, may eventually unlock some or all of life and death’s mysteries. In the meantime, groups of dedicated scientists continue to look for for the foundation of aging with a view to understanding the process and eventually slowing (and perhaps stopping) it. Richard Walker is one of these singularly focused researchers.

From the BBC:

Richard Walker has been trying to conquer ageing since he was a 26-year-old free-loving hippie. It was the 1960s, an era marked by youth: Vietnam War protests, psychedelic drugs, sexual revolutions. The young Walker relished the culture of exultation, of joie de vivre, and yet was also acutely aware of its passing. He was haunted by the knowledge that ageing would eventually steal away his vitality – that with each passing day his body was slightly less robust, slightly more decayed. One evening he went for a drive in his convertible and vowed that by his 40th birthday, he would find a cure for ageing.

Walker became a scientist to understand why he was mortal. “Certainly it wasn’t due to original sin and punishment by God, as I was taught by nuns in catechism,” he says. “No, it was the result of a biological process, and therefore is controlled by a mechanism that we can understand.”

Scientists have published several hundred theories of ageing, and have tied it to a wide variety of biological processes. But no one yet understands how to integrate all of this disparate information.

Walker, now 74, believes that the key to ending ageing may lie in a rare disease that doesn’t even have a real name, “Syndrome X”. He has identified four girls with this condition, marked by what seems to be a permanent state of infancy, a dramatic developmental arrest. He suspects that the disease is caused by a glitch somewhere in the girls’ DNA. His quest for immortality depends on finding it.

It’s the end of another busy week and MaryMargret Williams is shuttling her brood home from school. She drives an enormous SUV, but her six children and their coats and bags and snacks manage to fill every inch. The three big kids are bouncing in the very back. Sophia, 10, with a mouth of new braces, is complaining about a boy-crazy friend. She sits next to Anthony, seven, and Aleena, five, who are glued to something on their mother’s iPhone. The three little kids squirm in three car seats across the middle row. Myah, two, is mining a cherry slushy, and Luke, one, is pawing a bag of fresh crickets bought for the family gecko.

Finally there’s Gabrielle, who’s the smallest child, and the second oldest, at nine years old. She has long, skinny legs and a long, skinny ponytail, both of which spill out over the edges of her car seat. While her siblings giggle and squeal, Gabby’s dusty-blue eyes roll up towards the ceiling. By the calendar, she’s almost an adolescent. But she has the buttery skin, tightly clenched fingers and hazy awareness of a newborn.

Back in 2004, when MaryMargret and her husband, John, went to the hospital to deliver Gabby, they had no idea anything was wrong. They knew from an ultrasound that she would have clubbed feet, but so had their other daughter, Sophia, who was otherwise healthy. And because MaryMargret was a week early, they knew Gabby would be small, but not abnormally so. “So it was such a shock to us when she was born,” MaryMargret says.

Gabby came out purple and limp. Doctors stabilised her in the neonatal intensive care unit and then began a battery of tests. Within days the Williamses knew their new baby had lost the genetic lottery. Her brain’s frontal lobe was smooth, lacking the folds and grooves that allow neurons to pack in tightly. Her optic nerve, which runs between the eyes and the brain, was atrophied, which would probably leave her blind. She had two heart defects. Her tiny fists couldn’t be pried open. She had a cleft palate and an abnormal swallowing reflex, which meant she had to be fed through a tube in her nose. “They started trying to prepare us that she probably wouldn’t come home with us,” John says. Their family priest came by to baptise her.

Day after day, MaryMargret and John shuttled between Gabby in the hospital and 13-month-old Sophia at home. The doctors tested for a few known genetic syndromes, but they all came back negative. Nobody had a clue what was in store for her. Her strong Catholic family put their faith in God. “MaryMargret just kept saying, ‘She’s coming home, she’s coming home’,” recalls her sister, Jennie Hansen. And after 40 days, she did.

Gabby cried a lot, loved to be held, and ate every three hours, just like any other newborn. But of course she wasn’t. Her arms would stiffen and fly up to her ears, in a pose that the family nicknamed her “Harley-Davidson”. At four months old she started having seizures. Most puzzling and problematic, she still wasn’t growing. John and MaryMargret took her to specialist after specialist: a cardiologist, a gastroenterologist, a geneticist, a neurologist, an ophthalmologist and an orthopaedist. “You almost get your hopes up a little – ’This is exciting! We’re going to the gastro doctor, and maybe he’ll have some answers’,” MaryMargret says. But the experts always said the same thing: nothing could be done.

The first few years with Gabby were stressful. When she was one and Sophia two, the Williamses drove from their home in Billings, Montana, to MaryMargret’s brother’s home outside of St Paul, Minnesota. For nearly all of those 850 miles, Gabby cried and screamed. This continued for months until doctors realised she had a run-of-the-mill bladder infection. Around the same period, she acquired a severe respiratory infection that left her struggling to breathe. John and MaryMargret tried to prepare Sophia for the worst, and even planned which readings and songs to use at Gabby’s funeral. But the tiny toddler toughed it out.

While Gabby’s hair and nails grew, her body wasn’t getting bigger. She was developing in subtle ways, but at her own pace. MaryMargret vividly remembers a day at work when she was pushing Gabby’s stroller down a hallway with skylights in the ceiling. She looked down at Gabby and was shocked to see her eyes reacting to the sunlight. “I thought, ‘Well, you’re seeing that light!’” MaryMargret says. Gabby wasn’t blind, after all.

Despite the hardships, the couple decided they wanted more children. In 2007 MaryMargret had Anthony, and the following year she had Aleena. By this time, the Williamses had stopped trudging to specialists, accepting that Gabby was never going to be fixed. “At some point we just decided,” John recalls, “it’s time to make our peace.”

Mortal questions

When Walker began his scientific career, he focused on the female reproductive system as a model of “pure ageing”: a woman’s ovaries, even in the absence of any disease, slowly but inevitably slide into the throes of menopause. His studies investigated how food, light, hormones and brain chemicals influence fertility in rats. But academic science is slow. He hadn’t cured ageing by his 40th birthday, nor by his 50th or 60th. His life’s work was tangential, at best, to answering the question of why we’re mortal, and he wasn’t happy about it. He was running out of time.

So he went back to the drawing board. As he describes in his book, Why We Age, Walker began a series of thought experiments to reflect on what was known and not known about ageing.

Ageing is usually defined as the slow accumulation of damage in our cells, organs and tissues, ultimately causing the physical transformations that we all recognise in elderly people. Jaws shrink and gums recede. Skin slacks. Bones brittle, cartilage thins and joints swell. Arteries stiffen and clog. Hair greys. Vision dims. Memory fades. The notion that ageing is a natural, inevitable part of life is so fixed in our culture that we rarely question it. But biologists have been questioning it for a long time.

It’s a harsh world out there, and even young cells are vulnerable. It’s like buying a new car: the engine runs perfectly but is still at risk of getting smashed on the highway. Our young cells survive only because they have a slew of trusty mechanics on call. Take DNA, which provides the all-important instructions for making proteins. Every time a cell divides, it makes a near-perfect copy of its three-billion-letter code. Copying mistakes happen frequently along the way, but we have specialised repair enzymes to fix them, like an automatic spellcheck. Proteins, too, are ever vulnerable. If it gets too hot, they twist into deviant shapes that keep them from working. But here again, we have a fixer: so-called ‘heat shock proteins’ that rush to the aid of their misfolded brethren. Our bodies are also regularly exposed to environmental poisons, such as the reactive and unstable ‘free radical’ molecules that come from the oxidisation of the air we breathe. Happily, our tissues are stocked with antioxidants and vitamins that neutralise this chemical damage. Time and time again, our cellular mechanics come to the rescue.

Which leads to the biologists’ longstanding conundrum: if our bodies are so well tuned, why, then, does everything eventually go to hell?

One theory is that it all boils down to the pressures of evolution. Humans reproduce early in life, well before ageing rears its ugly head. All of the repair mechanisms that are important in youth – the DNA editors, the heat shock proteins, the antioxidants – help the young survive until reproduction, and are therefore passed down to future generations. But problems that show up after we’re done reproducing cannot be weeded out by evolution. Hence, ageing.

Most scientists say that ageing is not caused by any one culprit but by the breakdown of many systems at once. Our sturdy DNA mechanics become less effective with age, meaning that our genetic code sees a gradual increase in mutations. Telomeres, the sequences of DNA that act as protective caps on the ends of our chromosomes, get shorter every year. Epigenetic messages, which help turn genes on and off, get corrupted with time. Heat shock proteins run down, leading to tangled protein clumps that muck up the smooth workings of a cell. Faced with all of this damage, our cells try to adjust by changing the way they metabolise nutrients and store energy. To ward off cancer, they even know how to shut themselves down. But eventually cells stop dividing and stop communicating with each other, triggering the decline we see from the outside.

Scientists trying to slow the ageing process tend to focus on one of these interconnected pathways at a time. Some researchers have shown, for example, that mice on restricted-calorie diets live longer than normal. Other labs have reported that giving mice rapamycin, a drug that targets an important cell-growth pathway, boosts their lifespan. Still other groups are investigating substances that restore telomeres, DNA repair enzymes and heat shock proteins.

During his thought experiments, Walker wondered whether all of these scientists were fixating on the wrong thing. What if all of these various types of cellular damages were the consequences of ageing, but not the root cause of it? He came up with an alternative theory: that ageing is the unavoidable fallout of our development.

The idea sat on the back burner of Walker’s mind until the evening of 23 October 2005. He was working in his home office when his wife called out to him to join her in the family room. She knew he would want to see what was on TV: an episode of Dateline about a young girl who seemed to be “frozen in time”. Walker watched the show and couldn’t believe what he was seeing. Brooke Greenberg was 12 years old, but just 13 pounds (6kg) and 27 inches (69cm) long. Her doctors had never seen anything like her condition, and suspected the cause was a random genetic mutation. “She literally is the Fountain of Youth,” her father, Howard Greenberg, said.

Walker was immediately intrigued. He had heard of other genetic diseases, such as progeria and Werner syndrome, which cause premature ageing in children and adults respectively. But this girl seemed to be different. She had a genetic disease that stopped her development and with it, Walker suspected, the ageing process. Brooke Greenberg, in other words, could help him test his theory.

Uneven growth

Brooke was born a few weeks premature, with many birth defects. Her paediatrician labeled her with Syndrome X, not knowing what else to call it.

After watching the show, Walker tracked down Howard Greenberg’s address. Two weeks went by before Walker heard back, and after much discussion he was allowed to test Brooke. He was sent Brooke’s medical records as well as blood samples for genetic testing. In 2009, his team published a brief report describing her case.

Walker’s analysis found that Brooke’s organs and tissues were developing at different rates. Her mental age, according to standardised tests, was between one and eight months. Her teeth appeared to be eight years old; her bones, 10 years. She had lost all of her baby fat, and her hair and nails grew normally, but she had not reached puberty. Her telomeres were considerably shorter than those of healthy teenagers, suggesting that her cells were ageing at an accelerated rate.

All of this was evidence of what Walker dubbed “developmental disorganisation”. Brooke’s body seemed to be developing not as a coordinated unit, he wrote, but rather as a collection of individual, out-of-sync parts. “She is not simply ‘frozen in time’,” Walker wrote. “Her development is continuing, albeit in a disorganised fashion.”

The big question remained: why was Brooke developmentally disorganised? It wasn’t nutritional and it wasn’t hormonal. The answer had to be in her genes. Walker suspected that she carried a glitch in a gene (or a set of genes, or some kind of complex genetic programme) that directed healthy development. There must be some mechanism, after all, that allows us to develop from a single cell to a system of trillions of cells. This genetic programme, Walker reasoned, would have two main functions: it would initiate and drive dramatic changes throughout the organism, and it would also coordinate these changes into a cohesive unit.

Ageing, he thought, comes about because this developmental programme, this constant change, never turns off. From birth until puberty, change is crucial: we need it to grow and mature. After we’ve matured, however, our adult bodies don’t need change, but rather maintenance. “If you’ve built the perfect house, you would want to stop adding bricks at a certain point,” Walker says. “When you’ve built a perfect body, you’d want to stop screwing around with it. But that’s not how evolution works.” Because natural selection cannot influence traits that show up after we have passed on our genes, we never evolved a “stop switch” for development, Walker says. So we keep adding bricks to the house. At first this doesn’t cause much damage – a sagging roof here, a broken window there. But eventually the foundation can’t sustain the additions, and the house topples. This, Walker says, is ageing.

Brooke was special because she seemed to have been born with a stop switch. But finding the genetic culprit turned out to be difficult. Walker would need to sequence Brooke’s entire genome, letter by letter.

That never happened. Much to Walker’s chagrin, Howard Greenberg abruptly severed their relationship. The Greenbergs have not publicly explained why they ended their collaboration with Walker, and declined to comment for this article.

Second chance

In August 2009, MaryMargret Williams saw a photo of Brooke on the cover of People magazine, just below the headline “Heartbreaking mystery: The 16-year-old baby”. She thought Brooke sounded a lot like Gabby, so contacted Walker.

After reviewing Gabby’s details, Walker filled her in on his theory. Testing Gabby’s genes, he said, could help him in his mission to end age-related disease – and maybe even ageing itself.

This didn’t sit well with the Williamses. John, who works for the Montana Department of Corrections, often interacts with people facing the reality of our finite time on Earth. “If you’re spending the rest of your life in prison, you know, it makes you think about the mortality of life,” he says. What’s important is not how long you live, but rather what you do with the life you’re given. MaryMargret feels the same way. For years she has worked in a local dermatology office. She knows all too well the cultural pressures to stay young, and wishes more people would embrace the inevitability of getting older. “You get wrinkles, you get old, that’s part of the process,” she says.

But Walker’s research also had its upside. First and foremost, it could reveal whether the other Williams children were at risk of passing on Gabby’s condition.

For several months, John and MaryMargret hashed out the pros and cons. They were under no illusion that the fruits of Walker’s research would change Gabby’s condition, nor would they want it to. But they did want to know why. “What happened, genetically, to make her who she is?” John says. And more importantly: “Is there a bigger meaning for it?”

John and MaryMargret firmly believe that God gave them Gabby for a reason. Walker’s research offered them a comforting one: to help treat Alzheimer’s and other age-related diseases. “Is there a small piece that Gabby could present to help people solve these awful diseases?” John asks. “Thinking about it, it’s like, no, that’s for other people, that’s not for us.” But then he thinks back to the day Gabby was born. “I was in that delivery room, thinking the same thing – this happens to other people, not us.”

Still not entirely certain, the Williamses went ahead with the research.

Amassing evidence

Walker published his theory in 2011, but he’s only the latest of many researchers to think along the same lines. “Theories relating developmental processes to ageing have been around for a very long time, but have been somewhat under the radar for most researchers,” says Joao Pedro de Magalhaes, a biologist at the University of Liverpool. In 1932, for example, English zoologist George Parker Bidder suggested that mammals have some kind of biological “regulator” that stops growth after the animal reaches a specific size. Ageing, Bidder thought, was the continued action of this regulator after growth was done.

Subsequent studies showed that Bidder wasn’t quite right; there are lots of marine organisms, for example, that never stop growing but age anyway. Still, his fundamental idea of a developmental programme leading to ageing has persisted.

For several years, Stuart Kim’s group at Stanford University has been comparing which genes are expressed in young and old nematode worms. It turns out that some genes involved in ageing also help drive development in youth.

Kim suggested that the root cause of ageing is the “drift”, or mistiming, of developmental pathways during the ageing process, rather than an accumulation of cellular damage.

Other groups have since found similar patterns in mice and primates. One study, for example, found that many genes turned on in the brains of old monkeys and humans are the same as those expressed in young brains, suggesting that ageing and development are controlled by some of the same gene networks.

Perhaps most provocative of all, some studies of worms have shown that shutting down essential development genes in adults significantly prolongs life. “We’ve found quite a lot of genes in which this happened – several dozen,” de Magalhaes says.

Nobody knows whether the same sort of developmental-programme genes exist in people. But say that they do exist. If someone was born with a mutation that completely destroyed this programme, Walker reasoned, that person would undoubtedly die. But if a mutation only partially destroyed it, it might lead to a condition like what he saw in Brooke Greenberg or Gabby Williams. So if Walker could identify the genetic cause of Syndrome X, then he might also have a driver of the ageing process in the rest of us.

And if he found that, then could it lead to treatments that slow – or even end – ageing? “There’s no doubt about it,” he says.

Public stage

After agreeing to participate in Walker’s research, the Williamses, just like the Greenbergs before them, became famous. In January 2011, when Gabby was six, the television channel TLC featured her on a one-hour documentary. The Williams family also appeared on Japanese television and in dozens of newspaper and magazine articles.

Other than becoming a local celebrity, though, Gabby’s everyday life hasn’t changed much since getting involved in Walker’s research. She spends her days surrounded by her large family. She’ll usually lie on the floor, or in one of several cushions designed to keep her spine from twisting into a C shape. She makes noises that would make an outsider worry: grunting, gasping for air, grinding her teeth. Her siblings think nothing of it. They play boisterously in the same room, somehow always careful not to crash into her. Once a week, a teacher comes to the house to work with Gabby. She uses sounds and shapes on an iPad to try to teach cause and effect. When Gabby turned nine, last October, the family made her a birthday cake and had a party, just as they always do. Most of her gifts were blankets, stuffed animals and clothes, just as they are every year. Her aunt Jennie gave her make-up.

Walker teamed up with geneticists at Duke University and screened the genomes of Gabby, John and MaryMargret. This test looked at the exome, the 2% of the genome that codes for proteins. From this comparison, the researchers could tell that Gabby did not inherit any exome mutations from her parents – meaning that it wasn’t likely that her siblings would be able to pass on the condition to their kids. “It was a huge relief – huge,” MaryMargret says.

Still, the exome screening didn’t give any clues as to what was behind Gabby’s disease. Gabby carries several mutations in her exome, but none in a gene that would make sense of her condition. All of us have mutations littering our genomes. So it’s impossible to know, in any single individual, whether a particular mutation is harmful or benign – unless you can compare two people with the same condition.

All girls

Luckily for him, Walker’s continued presence in the media has led him to two other young girls who he believes have the same syndrome. One of them, Mackenzee Wittke, of Alberta, Canada, is now five years old, with has long and skinny limbs, just like Gabby. “We have basically been stuck in a time warp,” says her mother, Kim Wittke. The fact that all of these possible Syndrome X cases are girls is intriguing – it could mean that the crucial mutation is on their X chromosome. Or it could just be a coincidence.

Walker is working with a commercial outfit in California to compare all three girls’ entire genome sequences – the exome plus the other 98% of DNA code, which is thought to be responsible for regulating the expression of protein-coding genes.

For his theory, Walker says, “this is do or die – we’re going to do every single bit of DNA in these girls. If we find a mutation that’s common to them all, that would be very exciting.”

But that seems like a very big if.

Most researchers agree that finding out the genes behind Syndrome X is a worthwhile scientific endeavour, as these genes will no doubt be relevant to our understanding of development. They’re far less convinced, though, that the girls’ condition has anything to do with ageing. “It’s a tenuous interpretation to think that this is going to be relevant to ageing,” says David Gems, a geneticist at University College London. It’s not likely that these girls will even make it to adulthood, he says, let alone old age.

It’s also not at all clear that these girls have the same condition. Even if they do, and even if Walker and his collaborators discover the genetic cause, there would still be a steep hill to climb. The researchers would need to silence the same gene or genes in laboratory mice, which typically have a lifespan of two or three years. “If that animal lives to be 10, then we’ll know we’re on the right track,” Walker says. Then they’d have to find a way to achieve the same genetic silencing in people, whether with a drug or some kind of gene therapy. And then they’d have to begin long and expensive clinical trials to make sure that the treatment was safe and effective. Science is often too slow, and life too fast.

End of life

On 24 October 2013, Brooke passed away. She was 20 years old. MaryMargret heard about it when a friend called after reading it in a magazine. The news hit her hard. “Even though we’ve never met the family, they’ve just been such a part of our world,” she says.

MaryMargret doesn’t see Brooke as a template for Gabby – it’s not as if she now believes that she only has 11 years left with her daughter. But she can empathise with the pain the Greenbergs must be feeling. “It just makes me feel so sad for them, knowing that there’s a lot that goes into a child like that,” she says. “You’re prepared for them to die, but when it finally happens, you can just imagine the hurt.”

Today Gabby is doing well. MaryMargret and John are no longer planning her funeral. Instead, they’re beginning to think about what would happen if Gabby outlives them. (Sophia has offered to take care of her sister.) John turned 50 this year, and MaryMargret will be 41. If there were a pill to end ageing, they say they’d have no interest in it. Quite the contrary: they look forward to getting older, because it means experiencing the new joys, new pains and new ways to grow that come along with that stage of life.

Richard Walker, of course, has a fundamentally different view of growing old. When asked why he’s so tormented by it, he says it stems from childhood, when he watched his grandparents physically and psychologically deteriorate. “There was nothing charming to me about sedentary old people, rocking chairs, hot houses with Victorian trappings,” he says. At his grandparents’ funerals, he couldn’t help but notice that they didn’t look much different in death than they did at the end of life. And that was heartbreaking. “To say I love life is an understatement,” he says. “Life is the most beautiful and magic of all things.”

If his hypothesis is correct – who knows? – it might one day help prevent disease and modestly extend life for millions of people. Walker is all too aware, though, that it would come too late for him. As he writes in his book: “I feel a bit like Moses who, after wandering in the desert for most years of his life, was allowed to gaze upon the Promised Land but not granted entrance into it.”

 Read the entire story here.

Story courtesy of BBC and Mosaic under Creative Commons License.

Image: DNA structure. Courtesy of Wikipedia.

BigBang

Metabolism Without Life

Glycolysis2-pathway

A remarkable chance discovery in a Cambridge University research lab shows that a number of life-sustaining metabolic processes can occur spontaneously and outside of living cells. This opens a rich, new vein of theories and approaches to studying the origin of life.

From the New Scientist:

Metabolic processes that underpin life on Earth have arisen spontaneously outside of cells. The serendipitous finding that metabolism – the cascade of reactions in all cells that provides them with the raw materials they need to survive – can happen in such simple conditions provides fresh insights into how the first life formed. It also suggests that the complex processes needed for life may have surprisingly humble origins.

“People have said that these pathways look so complex they couldn’t form by environmental chemistry alone,” says Markus Ralser at the University of Cambridge who supervised the research.

But his findings suggest that many of these reactions could have occurred spontaneously in Earth’s early oceans, catalysed by metal ions rather than the enzymes that drive them in cells today.

The origin of metabolism is a major gap in our understanding of the emergence of life. “If you look at many different organisms from around the world, this network of reactions always looks very similar, suggesting that it must have come into place very early on in evolution, but no one knew precisely when or how,” says Ralser.

Happy accident

One theory is that RNA was the first building block of life because it helps to produce the enzymes that could catalyse complex sequences of reactions. Another possibility is that metabolism came first; perhaps even generating the molecules needed to make RNA, and that cells later incorporated these processes – but there was little evidence to support this.

“This is the first experiment showing that it is possible to create metabolic networks in the absence of RNA,” Ralser says.

Remarkably, the discovery was an accident, stumbled on during routine quality control testing of the medium used to culture cells at Ralser’s laboratory. As a shortcut, one of his students decided to run unused media through a mass spectrometer, which spotted a signal for pyruvate – an end product of a metabolic pathway called glycolysis.

To test whether the same processes could have helped spark life on Earth, they approached colleagues in the Earth sciences department who had been working on reconstructing the chemistry of the Archean Ocean, which covered the planet almost 4 billion years ago. This was an oxygen-free world, predating photosynthesis, when the waters were rich in iron, as well as other metals and phosphate. All these substances could potentially facilitate chemical reactions like the ones seen in modern cells.

Metabolic backbone

Ralser’s team took early ocean solutions and added substances known to be starting points for modern metabolic pathways, before heating the samples to between 50 ?C and 70 ?C – the sort of temperatures you might have found near a hydrothermal vent – for 5 hours. Ralser then analysed the solutions to see what molecules were present.

“In the beginning we had hoped to find one reaction or two maybe, but the results were amazing,” says Ralser. “We could reconstruct two metabolic pathways almost entirely.”

The pathways they detected were glycolysis and the pentose phosphate pathway, “reactions that form the core metabolic backbone of every living cell,” Ralser adds. Together these pathways produce some of the most important materials in modern cells, including ATP – the molecule cells use to drive their machinery, the sugars that form DNA and RNA, and the molecules needed to make fats and proteins.

If these metabolic pathways were occurring in the early oceans, then the first cells could have enveloped them as they developed membranes.

In all, 29 metabolism-like chemical reactions were spotted, seemingly catalysed by iron and other metals that would have been found in early ocean sediments. The metabolic pathways aren’t identical to modern ones; some of the chemicals made by intermediate steps weren’t detected. However, “if you compare them side by side it is the same structure and many of the same molecules are formed,” Ralser says. These pathways could have been refined and improved once enzymes evolved within cells.

Read the entire article here.

Image: Glycolysis metabolic pathway. Courtesy of Wikipedia.

BigBang

Meet the Indestructible Life-form

water-bear

Meet the water bear or tardigrade. It may not be pretty, but its as close to indestructible as any life-form may ever come.

Cool it to a mere 1 degree above absolute zero or -458 F and it lives on. Heat it to 300 F and it lives on. Throw it out into the vacuum of space and it lives on. Irradiate it with hundreds of times the radiation that would kill a human and it lives on. Dehydrate it to 3 percent of its normal water content and it lives on.

From Wired:

In 1933, the owner of a New York City speakeasy and three cronies embarked on a rather unoriginal scheme to make a quick couple grand: Take out three life insurance policies on the bar’s deepest alcoholic, Mike Malloy, then kill him.

First, they pumped him full of ungodly amounts of liquor. When that didn’t work, they poisoned the hooch. Mike didn’t mind. Then came the sandwiches of rotten sardines and broken glass and metal shavings. Mike reportedly loved them. Next they dropped him in the snow and poured cold water on him. It didn’t faze Mike. Then they ran him over with a cab, which only broke his arm. The conspirators finally succeeded when they boozed Mike up, ran a tube down his throat, and pumped him full of carbon monoxide.

They don’t come much tougher than Mike the Durable, as he is remembered. Except in the microscopic world beneath our feet, where there lives what is perhaps the toughest creature on Earth: the tardigrade. Also known as the water bear (because it looks like an adorable little many-legged bear), this exceedingly tiny critter has an incredible resistance to just about everything. Go ahead and boil it, freeze it, irradiate it, and toss it into the vacuum of space — it won’t die. If it were big enough to eat a glass sandwich, it probably could survive that too.

The water bear’s trick is something called cryptobiosis, in which it brings its metabolic processes nearly to a halt. In this state it can dehydrate to 3 percent of its normal water content in what is called desiccation, becoming a husk of its former self. But just add water and the tardigrade roars back to life like Mike the Durable emerging from a bender and continues trudging along, puncturing algae and other organisms with a mouthpart called a stylet and sucking out the nutrients.

“They are probably the most extreme survivors that we know of among animals,” said biologist Bob Goldstein of the University of North Carolina at Chapel Hill. “People talk about cockroaches surviving anything. I think long after the cockroaches would be killed we’d still have dried water bears that could be rehydrated and be alive.”

“Is It Cold in Here?” Asked a Water Bear NEVER

This hibernation of sorts isn’t happening for a single season, like a true bear (tardigrades are invertebrates). As far as scientists can tell, water bears can be dried out for at least a decade and still revivify, only to find their clothes are suddenly out of style.

Mike the Durable did just fine in the freezing cold, but the temperatures the water bear endures in cryptobiosis defy belief. It can survive in a lab environment of just 1 degree kelvin. That’s an astonishing -458 degrees Fahrenheit, where matter goes bizarro, with gases becoming liquids and liquids becoming solids.

At this temperature the movements of the normally frenzied atoms inside the water bear come almost to a standstill, yet the creature endures. And that’s all the more incredible when you consider that the water bear indeed has a brain, a relatively simple one, sure, but a brain that somehow emerges from this unscathed.

Water bears also can tolerate pressures six times that of the deepest oceans. And a few of them once survived an experiment that subjected them to 10 days exposed to the vacuum of space. (While we’re on the topic, humans can survive for a couple minutes, max. One poor fellow at NASA accidentally depressurized his suit in a vacuum chamber in 1965 and lost consciousness after 15 seconds. When he woke up, he said his last memory was feeling the water on his tongue boiling, which I’m guessing felt a bit like Pop Rocks, only somehow even worse for your body.)

Anyway, tardigrades. They can take hundreds of times the radiation that would kill a human. Water bears don’t mind hot water either–like, 300 degrees Fahrenheit hot. So the question is: why? Why evolve to survive the kind of cold that only scientists can create in a lab, and pressures that have never even existed on our planet?

Water bears don’t even necessarily inhabit extreme habitats like, say, boiling springs where certain bacteria proliferate. Therefore the term “extremophile” that has been applied to tardigrades over the years isn’t entirely accurate. Just because they’re capable of surviving these harsh environments doesn’t mean they seek them out.

They actually prefer regular old dirt and sand and moss all over the world. I mean, would you rather stay in a Motel 6 in a lake of boiling acidic water or lounge around on a beach resort and drink algae cocktails? (Why this isn’t a BuzzFeed quiz yet is beyond me. It’s gold. There’s untold billions of water bears on Earth. Page views, BuzzFeed. What’s the sound of a billion water bears clicking? Boom, another quiz.)

But that isn’t to say there aren’t troubles in the tardigrade version of paradise. “If you’re living in dirt,” said Goldstein, “there’s a danger of desiccation all the time.” If, say, the sun starts drying out the surface, one option is to move farther down into the soil. But “if you go too far down, there’s not going to be much food. So they really probably have to live in a fringe where they need to get food, but there’s always danger of drying out.”

A Tiny Superhero That Could One Day Save Your Life

And so it could be that the water bear’s incredible feats of survival may simply stem from a tough life in the dirt. But there’s also the question of how it does this, and it’s a perplexing one at that. Goldstein’s lab is researching this, and he reckons that water bears don’t just have one simple trick, but a range of strategies to be able to endure drying out and eventually reanimating.

“There’s one that we know of, which is some animals that survive drying make a sugar called trehalose,” he said. “And trehalose sort of replaces water as they dry down, so it will make glassy surfaces where normally water would be sitting. That probably helps prevent a lot of the damage that normally occurs when you dry something down or when you rehydrate it.” Not all of the 1,000 or so species of water bears produce this sugar though, he says, so there must be some other trick going on.

Ironically enough, these incredibly hardy creatures are very difficult to grow in the lab, but Goldstein has had great success where many others have failed. And, like so many great things in this world, it all began in a shed in England, where a regular old chap mastered their breeding to sell them to local schools for scientific experiments. He was so good at it, in fact, that he never needed to venture out to recollect specimens. And their descendants now crawl around Goldstein’s lab, totally unaware of how incredibly lucky they are to not be tortured by school children day in and day out.

A scanning electron micrograph of three awkwardly cuddling water bears. “You know what they say: Two’s company, three’s a crowd. We’re looking at you, Paul. Seriously though, Paul. You need to scram.” Image: Willow Gabriel

“Some organisms just can’t be raised in labs,” Goldstein said. “You bring them in and try to mimic what’s going on outside and they just don’t grow up. So we were lucky, actually, people were having a hard time growing water bears in labs continuously. And this guy in England had figured it out.”

Thanks to this breakthrough, Goldstein and other scientists are exploring the possibility of utilizing the water bear as science’s next fruit fly, that ubiquitous test subject that has yielded so many momentous discoveries. The water bear’s small size means you can pack a ton of them into a lab, plus they reproduce quickly and have a relatively compact genome to work with. Also, they’re way cuter than fruit flies and they don’t fall into your sodas and stuff.

Read the entire article here.

Image: A scanning electron micrograph of a water bear.  Courtesy: Bob Goldstein and Vicky Madden / Wired.

BigBang

Revisiting Drake

In 1960 radio astronomer Frank Drake began the first systematic search for intelligent signals emanating from space. He was not successful, but his pioneering efforts paved the way for numerous other programs, including SETI (Search for Extra-Terrestrial Intelligence). The Drake Equation is named for him, and put simply, gives an estimate of the number of active, extraterrestrial civilizations with methods of communication in our own galaxy. Drake postulated the equation as a way to get the scientific community engaged in the search for life beyond our home planet.

The Drake equation is:

N = R^{\ast} \cdot f_p \cdot n_e \cdot f_{\ell} \cdot f_i \cdot f_c \cdot L

where:

N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone); and

R* = the average number of star formation per year in our galaxy

fp = the fraction of those stars that have planets

ne = the average number of planets that can potentially support life per star that has planets

fl = the fraction of planets that could support life that actually develop life at some point

fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)

fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

L = the length of time for which such civilizations release detectable signals into space

Now, based on recent discoveries of hundreds of extra-solar planets, or exoplanets (those beyond our solar system), by the Kepler space telescope and other Earth-bound observatories, researchers are fine-tuning the original Drake Equation for the 21st century.

From the New Scientist:

An iconic tool in the search for extraterrestrial life is getting a 21st-century reboot – just as our best planet-hunting telescope seems to have died. Though the loss of NASA’s Kepler telescope is a blow, the reboot could mean we find signs of life on extrasolar planets within a decade.

The new tool takes the form of an equation. In 1961 astronomer Frank Drake scribbled his now-famous equation for calculating the number of detectable civilisations in the Milky Way. The Drake equation includes a number of terms that at the time seemed unknowable – including the very existence of planets beyond our solar system.

But the past two decades have seen exoplanets pop up like weeds, particularly in the last few years thanks in large part to the Kepler space telescope. Launched in 2009Movie Camera, Kepler has found more than 130 worlds and detected 3000 or so more possibles. The bounty has given astronomers the first proper census of planets in one region of our galaxy, allowing us to make estimates of the total population of life-friendly worlds across the Milky Way.

With that kind of data in hand, Sara Seager at the Massachusetts Institute of Technology reckons the Drake equation is ripe for a revamp. Her version narrows a few of the original terms to account for our new best bets of finding life, based in part on what Kepler has revealed. If the original Drake equation was a hatchet, the new Seager equation is a scalpel.

Seager presented her work this week at a conference in Cambridge, Massachusetts, entitled “Exoplanets in the Post-Kepler Era”. The timing could not be more prescient. Last week Kepler suffered a surprise hardware failure that knocked out its ability to see planetary signals clearly. If it can’t be fixed, the mission is over.

“When we talked about the post-Kepler era, we thought that would be three to four years from now,” co-organiser David Charbonneau of the Harvard-Smithsonian Center for Astrophysics said last week. “We now know the post-Kepler era probably started two days ago.”

But Kepler has collected data for four years, slightly longer than the mission’s original goal, and so far only the first 18 months’ worth have been analysed. That means it may have already gathered enough information to give alien-hunters a fighting chance.

The original Drake equation includes seven terms, which multiplied together give the number of intelligent alien civilisations we could hope to detect (see diagram). Kepler was supposed to pin down two terms: the fraction of stars that have planets, and the number of those planets that are habitable.

To do that, Kepler had been staring unflinchingly at some 150,000 stars near the constellation Cygnus, looking for periodic changes in brightness caused by a planet crossing, or transiting, a star’s face as seen from Earth. This method tells us a planet’s size and its rough distance from its host star.

Size gives a clue to a planet’s composition, which tells us whether it is rocky like Earth or gassy like Neptune. Before Kepler, only a few exoplanets had been identified as small enough to be rocky, because other search methods were better suited to spotting larger, gas giant worlds.

“Kepler is the single most revolutionary project that has ever been undertaken in exoplanets,” says Charbonneau. “It broke open the piggybank and rocky planets poured out.” A planet’s distance from its star is also crucial, because that tells us whether the temperature is right for liquid water – and so perhaps life – to exist.

But with Kepler’s recent woes, hopes of finding enough potentially habitable planets, or Earth twins, to satisfy the Drake equation have dimmed. The mission was supposed to run for three-and-a-half years, which should have been enough to pinpoint Earth-sized planets with years of a similar length. After the telescope came online, the mission team realised that other sun-like stars are more active than ours, and they bounce around too much in the telescope’s field of view. To find enough Earths, they would need seven or eight years of data.

Read the entire article here.

Image courtesy of the BBC. Drake Equation courtesy of Wikipedia.

BigBang

From RNA Chemistry to Cell Biology

Each day we inch towards a better scientific understanding of how life is thought to have begun on our planet. Over the last decade researchers have shown how molecules like the nucleotides that make up complex chains of RNA (ribonucleic acid) and DNA (deoxyribonucleic acid) may have formed in the primaeval chemical soup of the early Earth. But it’s altogether a much greater leap to get from RNA (or DNA) to even a simple biological cell. Some recent work sheds more light and suggests that the chemical to biological chasm between long-strands of RNA and a complex cell may not be as wide to cross as once thought.

From ars technica:

Origin of life researchers have made impressive progress in recent years, showing that simple chemicals can combine to make nucleotides, the building blocks of DNA and RNA. Given the right conditions, these nucleotides can combine into ever-longer stretches of RNA. A lot of work has demonstrated that RNAs can perform all sorts of interesting chemistry, specifically binding other molecules and catalyzing reactions.

So the case for life getting its start in an RNA world has gotten very strong in the past decade, but the difference between a collection of interesting RNAs and anything like a primitive cell—surrounded by membranes, filled with both RNA and proteins, and running a simple metabolism—remains a very wide chasm. Or so it seems. A set of papers that came out in the past several days suggest that the chasm might not be as large as we’d tend to think.

Ironing out metabolism

A lot of the basic chemistry that drives the cell is based on electron transport, typically involving proteins that contain an iron atom. These reactions not only create some of the basic chemicals that are necessary for life, they’re also essential to powering the cell. Both photosynthesis and the breakdown of sugars involve the transfer of electrons to and from proteins that contain an iron atom.

DNA and RNA tend to have nothing to do with iron, interacting with magnesium instead. But some researchers at Georgia Tech have considered that fact a historical accident. Since photosynthesis put so much oxygen into the atmosphere, most of the iron has been oxidized into a state where it’s not soluble in water. If you go back to before photosynthesis was around, the oceans were filled with dissolved iron. Previously, the group had shown that, in oxygen-free and iron rich conditions, RNAs would happily work with iron instead and that its presence could speed up their catalytic activity.

Now the group is back with a new paper showing that if you put a bunch of random RNAs into the same conditions, some of them can catalyze electron transfer reactions. By “random,” I mean RNAs that are currently used by cells to do completely unrelated things (specifically, ribosomal and transfer RNAs). The reactions they catalyze are very simple, but remember: these RNAs don’t normally function as a catalyst at all. It wouldn’t surprise me if, after a number of rounds of evolutionary selection, an iron-RNA combination could be found that catalyzes a reaction that’s a lot closer to modern metabolism.

All of which suggests that the basics of a metabolism could have gotten started without proteins around.

Proteins build membranes

Clearly, proteins showed up at some point. They certainly didn’t look much like the proteins we see today, which may have hundreds or thousands of amino acids linked together. In fact, they may not have looked much like proteins at all, if a paper from Jack Szostak’s group is any indication. Szostak’s found that just two amino acids linked together may have catalytic activity. Some of that activity can help them engage in competition over another key element of the first cells: membrane material.

The work starts with a two amino acid long chemical called a peptide. If that peptide happens to be serine linked to histidine (two amino acids in use by life today), it has an interesting chemical activity: very slowly and poorly, it links other amino acids together to form more peptides. This weak activity is especially true if the amino acids are phenylalanine and leucine, two water-hating chemicals. Once they’re linked, they will precipitate out of a water solution.

The authors added a fatty acid membrane, figuring that it would soak up the reaction product. That definitely worked, with the catalytic efficiency of serine-histidine going up as a result. But something else happened as well: membranes that incorporated the reaction product started growing. It turns out that its presence in the membrane made it an efficient scrounger of other membrane material. As they grew, these membranes extended as long filaments that would break up into smaller parts with a gentle agitation and then start growing all over again.

In fact, the authors could set up a bit of a Darwinian competition between membranes based on how much starting catalyst each had. All of which suggests that proteins might have found their way into the cell as very simple chemicals that, at least initially, weren’t in any way connected to genetic and biochemical functions performed by RNA. But any cell-like things that evolved an RNA that made short proteins could have a big advantage over its competition.

Read the entire article here.

BigBang

Idyllic Undeveloped Land: Only 1,200 Light Years Away

Humans may soon make their only home irreversibly uninhabitable. Fortunately, astronomers have recently discovered a couple of exo-planets capable of sustaining life. Unfortunately, they are a little too distant — using current technology it would take humans around 26 million years. But, we can still dream.

From the New York Times:

Astronomers said Thursday that they had found the most Earth-like worlds yet known in the outer cosmos, a pair of planets that appear capable of supporting life and that orbit a star 1,200 light-years from here, in the northern constellation Lyra.

They are the two outermost of five worlds circling a yellowish star slightly smaller and dimmer than our Sun, heretofore anonymous and now destined to be known in the cosmic history books as Kepler 62, after NASA’s Kepler spacecraft, which discovered them. These planets are roughly half again as large as Earth and are presumably balls of rock, perhaps covered by oceans with humid, cloudy skies, although that is at best a highly educated guess.

Nobody will probably ever know if anything lives on these planets, and the odds are that humans will travel there only in their faster-than-light dreams, but the news has sent astronomers into heavenly raptures. William Borucki of NASA’s Ames Research Center, head of the Kepler project, described one of the new worlds as the best site for Life Out There yet found in Kepler’s four-years-and-counting search for other Earths. He treated his team to pizza and beer on his own dime to celebrate the find (this being the age of sequestration). “It’s a big deal,” he said.

Looming brightly in each other’s skies, the two planets circle their star at distances of 37 million and 65 million miles, about as far apart as Mercury and Venus in our solar system. Most significantly, their orbits place them both in the “Goldilocks” zone of lukewarm temperatures suitable for liquid water, the crucial ingredient for Life as We Know It.

Goldilocks would be so jealous.

Previous claims of Goldilocks planets with “just so” orbits snuggled up to red dwarf stars much dimmer and cooler than the Sun have had uncertainties in the size and mass and even the existence of these worlds, said David Charbonneau of the Harvard-Smithsonian Center for Astrophysics, an exoplanet hunter and member of the Kepler team.

“This is the first planet that ticks both boxes,” Dr. Charbonneau said, speaking of the outermost planet, Kepler 62f. “It’s the right size and the right temperature.” Kepler 62f is 40 percent bigger than Earth and smack in the middle of the habitable zone, with a 267-day year. In an interview, Mr. Borucki called it the best planet Kepler has found.

Its mate, known as Kepler 62e, is slightly larger — 60 percent bigger than Earth — and has a 122-day orbit, placing it on the inner edge of the Goldilocks zone. It is warmer but also probably habitable, astronomers said.

The Kepler 62 system resembles our own solar system, which also has two planets in the habitable zone: Earth — and Mars, which once had water and would still be habitable today if it were more massive and had been able to hang onto its primordial atmosphere.

The Kepler 62 planets continue a string of breakthroughs in the last two decades in which astronomers have gone from detecting the first known planets belonging to other stars, or exoplanets, broiling globs of gas bigger than Jupiter, to being able to discern smaller and smaller more moderate orbs — iceballs like Neptune and, now, bodies only a few times the mass of Earth, known technically as super-Earths. Size matters in planetary affairs because we can’t live under the crushing pressure of gas clouds on a world like Jupiter. Life as We Know It requires solid ground and liquid water — a gentle terrestrial environment, in other words.

Kepler 62’s newfound worlds are not quite small enough to be considered strict replicas of Earth, but the results have strengthened the already strong conviction among astronomers that the galaxy is littered with billions of Earth-size planets, perhaps as many as one per star, and that astronomers will soon find Earth 2.0, as they call it — our lost twin bathing in the rays of an alien sun.

“Kepler and other experiments are finding planets that remind us more and more of home,” said Geoffrey Marcy, a longtime exoplanet hunter at the University of California, Berkeley, and Kepler team member. “It’s an amazing moment in science. We haven’t found Earth 2.0 yet, but we can taste it, smell it, right there on our technological fingertips.”

Read the entire article following the jump.

Image: The Kepler 62 system: homes away from home. Courtesy of JPL-Caltech/Ames/NASA.

BigBang

Looking for Alien Engineering Work

We haven’t yet found any aliens inhabiting exoplanets orbiting distant stars. We haven’t received any intelligently manufactured radio signals from deep space. And, unless you subscribe to the conspiracy theories surrounding Roswell Area 51, it’s unlikely that we’ve been visited by an extra-terrestrial intelligence.

Most reasonable calculations suggest that the universe should be teeming with life beyond our small, blue planet. So, where are all the aliens and why haven’t we been contacted yet? Not content to wait, some astronomers believe we should be looking for evidence of distant alien engineering projects.

From the New Scientist:

ALIENS: where are you? Our hopes of finding intelligent companionship seem to be constantly receding. Mars and Venus are not the richly populated realms we once guessed at. The icy seas of the outer solar system may hold life, but almost certainly no more than microbes. And the search for radio signals from more distant extraterrestrials has so frustrated some astronomers that they are suggesting we shout out an interstellar “Hello”, in the hope of prodding the dozy creatures into a response.

So maybe we need to think along different lines. Rather than trying to intercept alien communications, perhaps we should go looking for alien artefacts.

There have already been a handful of small-scale searches, but now three teams of astronomers are setting out to scan a much greater volume of space (see diagram). Two groups hope to see the shadows of alien industry in fluctuating starlight. The third, like archaeologists sifting through a midden heap on Earth, is hunting for alien waste.

What they’re after is something rather grander than flint arrowheads or shards of pottery. Something big. Planet-sized power stations. Star-girdling rings or spheres. Computers the size of a solar system. Perhaps even an assembly of hardware so vast it can darken an entire galaxy.

It might seem crazy to even entertain the notion of such stupendous celestial edifices, let alone go and look for them. Yet there is a simple rationale. Unless tool-users are always doomed to destroy themselves, any civilisation out there is likely to be far older and far more advanced than ours.

Humanity has already covered vast areas of Earth’s surface with roads and cities, and begun sending probes to other planets. If we can do all this in a matter of centuries, what could more advanced civilisations do over many thousands or even millions of years?

In 1960, the physicist Freeman Dyson pointed out that if alien civilisations keep growing and expanding, they will inevitably consume ever more energy – and the biggest source of energy in any star system is the star itself. Our total power consumption today is equivalent to about 0.01 per cent of the sunlight falling on Earth, so solar power could easily supply all our needs. If energy demand keeps growing at 1 per cent a year, however, then in 1000 years we’d need more energy than strikes the surface of the planet. Other energy sources, such as nuclear fusion, cannot solve the problem because the waste heat would fry the planet.

In a similar position, alien civilisations could start building solar power plants, factories and even habitats in space. With material mined from asteroids, then planets, and perhaps even the star itself, they could really spread out. Dyson’s conclusion was that after thousands or millions of years, the star might be entirely surrounded by a vast artificial sphere of solar panels.

The scale of a Dyson sphere is almost unimaginable. A sphere with a radius similar to that of Earth’s orbit would have more than a hundred million times the surface area of Earth. Nobody thinks building it would be easy. A single shell is almost certainly out, as it would be under extraordinary stresses and gravitationally unstable. A more plausible option is a swarm: many huge power stations on orbits that do not intersect, effectively surrounding the star. Dyson himself does not like to speculate on the details, or on the likelihood of a sphere being built. “We have no way of judging,” he says. The crucial point is that if any aliens have built Dyson spheres, there is a chance we could spot them.

A sphere would block the sun’s light, making it invisible to our eyes, but the sphere would still emit waste heat in the form of infrared radiation. So, as Carl Sagan pointed out in 1966, if infrared telescopes spot a warm object but nothing shows up at visible wavelengths, it could be a Dyson sphere.

Some natural objects can produce the same effect. Very young and very old stars are often surrounded by dust and gas, which blocks their light and radiates infrared. But the infrared spectrum of these objects should be a giveaway. Silicate minerals in dust produce a distinctive broad peak in the spectrum, and molecules in a warm gas would produce bright or dark spectral lines at specific wavelengths. By contrast, waste heat from a sphere should have a smooth, featureless thermal spectrum. “We would be hoping that the spectrum looks boring,” says Matt Povich at the California State Polytechnic University in Pomona. “The more boring the better.”

Our first good view of the sky at the appropriate wavelengths came when the Infrared Astronomical Satellite surveyed the skies for 10 months in 1983, and a few astronomers have sifted through its data. Vyacheslav Slysh at the Space Research Institute in Moscow made the first attempt in 1985, and Richard Carrigan at Fermilab in Illinois published the latest search in 2009. “I wanted to get into the mode of the British Museum, to go and look for artefacts,” he says.

Carrigan found no persuasive sources, but the range of his search was limited. It would have detected spheres around sunlike stars only within 1000 light years of Earth. This is a very small part of the Milky Way, which is 100,000 light years across.

One reason few have joined Carrigan in the hunt for artefacts is the difficulty of getting funding for such projects. Then last year, the Templeton Foundation – an organisation set up by a billionaire to fund research into the “big questions” – invited proposals for its New Frontiers programme, specifically requesting research that would not normally be funded because of its speculative nature. A few astronomers jumped at the chance to look for alien contraptions and, in October, the programme approved three separate searches. The grants are just a couple of hundred thousand dollars each, but they do not have to fund new telescopes, only new analysis.

One team, led by Jason Wright at Pennsylvania State University in University Park, will look for the waste heat of Dyson spheres by analysing data from two space-based infrared observatories, the Wide-field Infrared Survey Explorer (WISE) and the Spitzer space telescope, launched in 2009 and 2003. Povich, a member of this team, is looking specifically within the Milky Way. Thanks to the data from Spitzer and WISE, Povich should be able to scan a volume of space thousands of times larger than previous searches like Carrigan’s. “For example, if you had a sun-equivalent star, fully enclosed in a Dyson sphere, we should be able to detect it almost anywhere in the galaxy.”

Even such a wide-ranging hunt may not be ambitious enough, according to Wright. He suspects that interstellar travel will prove no harder than constructing a sphere. An alien civilisation with such a high level of technology would spread out and colonise the galaxy in a few million years, building spheres as they go. “I would argue that it’s very hard for a spacefaring civilisation to die out. There are too many lifeboats,” says Wright. “Once you have self-sufficient colonies, you will take over the galaxy – you can’t even try to stop it because you can’t coordinate the actions of the colonies.”

If this had happened in the Milky Way, there should be spheres everywhere. “To find one or a few Dyson spheres in our galaxy would be very strange,” says Wright.

Read the entire article after the jump.

Image: 2001: A Space Odyssey, The Monolith. Courtesy of Daily Galaxy.

BigBang

The Immortal Jellyfish

In 1988 marine-biology student made a stunning discovery, though little publicized at the time. In the coral blooms of the Italian Mediterranean Christian Rapallo found a small creature that resembled a jellyfish. It showed a very odd attribute — it refused to die. The true importance of this discovery did not become fully apparent until 1996, when a group of researchers found that this invertebrate, now classified as a hydrozoan and known by its scientific name Turritopsis dohrnii, could at any point during its lifecycle revert back to an earlier stage, and then begin its development all over again. It was to all intents immortal.

For scientists seeking to unravel the mechanisms that underlie the aging process Turritopsis dohrnii — the immortal jellyfish — represents a truly significant finding. Might our progress in slowing or even halting aging in humans come from a lowly jellyfish? Time will tell.

[div class=attrib]From the New York Times:[end-div]

After more than 4,000 years — almost since the dawn of recorded time, when Utnapishtim told Gilgamesh that the secret to immortality lay in a coral found on the ocean floor — man finally discovered eternal life in 1988. He found it, in fact, on the ocean floor. The discovery was made unwittingly by Christian Sommer, a German marine-biology student in his early 20s. He was spending the summer in Rapallo, a small city on the Italian Riviera, where exactly one century earlier Friedrich Nietzsche conceived “Thus Spoke Zarathustra”: “Everything goes, everything comes back; eternally rolls the wheel of being. Everything dies, everything blossoms again. . . .”

Sommer was conducting research on hydrozoans, small invertebrates that, depending on their stage in the life cycle, resemble either a jellyfish or a soft coral. Every morning, Sommer went snorkeling in the turquoise water off the cliffs of Portofino. He scanned the ocean floor for hydrozoans, gathering them with plankton nets. Among the hundreds of organisms he collected was a tiny, relatively obscure species known to biologists as Turritopsis dohrnii. Today it is more commonly known as the immortal jellyfish.

Sommer kept his hydrozoans in petri dishes and observed their reproduction habits. After several days he noticed that his Turritopsis dohrnii was behaving in a very peculiar manner, for which he could hypothesize no earthly explanation. Plainly speaking, it refused to die. It appeared to age in reverse, growing younger and younger until it reached its earliest stage of development, at which point it began its life cycle anew.

Sommer was baffled by this development but didn’t immediately grasp its significance. (It was nearly a decade before the word “immortal” was first used to describe the species.) But several biologists in Genoa, fascinated by Sommer’s finding, continued to study the species, and in 1996 they published a paper called “Reversing the Life Cycle.” The scientists described how the species — at any stage of its development — could transform itself back to a polyp, the organism’s earliest stage of life, “thus escaping death and achieving potential immortality.” This finding appeared to debunk the most fundamental law of the natural world — you are born, and then you die.

One of the paper’s authors, Ferdinando Boero, likened the Turritopsis to a butterfly that, instead of dying, turns back into a caterpillar. Another metaphor is a chicken that transforms into an egg, which gives birth to another chicken. The anthropomorphic analogy is that of an old man who grows younger and younger until he is again a fetus. For this reason Turritopsis dohrnii is often referred to as the Benjamin Button jellyfish.

Yet the publication of “Reversing the Life Cycle” barely registered outside the academic world. You might expect that, having learned of the existence of immortal life, man would dedicate colossal resources to learning how the immortal jellyfish performs its trick. You might expect that biotech multinationals would vie to copyright its genome; that a vast coalition of research scientists would seek to determine the mechanisms by which its cells aged in reverse; that pharmaceutical firms would try to appropriate its lessons for the purposes of human medicine; that governments would broker international accords to govern the future use of rejuvenating technology. But none of this happened.

Some progress has been made, however, in the quarter-century since Christian Sommer’s discovery. We now know, for instance, that the rejuvenation of Turritopsis dohrnii and some other members of the genus is caused by environmental stress or physical assault. We know that, during rejuvenation, it undergoes cellular transdifferentiation, an unusual process by which one type of cell is converted into another — a skin cell into a nerve cell, for instance. (The same process occurs in human stem cells.) We also know that, in recent decades, the immortal jellyfish has rapidly spread throughout the world’s oceans in what Maria Pia Miglietta, a biology professor at Notre Dame, calls “a silent invasion.” The jellyfish has been “hitchhiking” on cargo ships that use seawater for ballast. Turritopsis has now been observed not only in the Mediterranean but also off the coasts of Panama, Spain, Florida and Japan. The jellyfish seems able to survive, and proliferate, in every ocean in the world. It is possible to imagine a distant future in which most other species of life are extinct but the ocean will consist overwhelmingly of immortal jellyfish, a great gelatin consciousness everlasting.

[div class=attrib]Read the entire article following the jump.[end-div]

[div class=attrib]Image of Turritopsis dohrnii, courtesy of Discovery News.[end-div]

BigBang

The Inevitability of Life: A Tale of Protons and Mitochondria

A fascinating article by Nick Lane a leading researcher into the origins of life. Lane is a Research Fellow at University College London.

He suggests that it would be surprising if simple, bacterial-like, life were not common throughout the universe. However, the acquisition of one cell by another — an event that led to all higher organisms on planet Earth, is an altogether much rarer occurrence. So are we alone in the universe?

[div class=attrib]From the New Scientist:[end-div]

UNDER the intense stare of the Kepler space telescope, more and more planets similar to our own are revealing themselves to us. We haven’t found one exactly like Earth yet, but so many are being discovered that it appears the galaxy must be teeming with habitable planets.

These discoveries are bringing an old paradox back into focus. As physicist Enrico Fermi asked in 1950, if there are many suitable homes for life out there and alien life forms are common, where are they all? More than half a century of searching for extraterrestrial intelligence has so far come up empty-handed.

Of course, the universe is a very big place. Even Frank Drake’s famously optimistic “equation” for life’s probability suggests that we will be lucky to stumble across intelligent aliens: they may be out there, but we’ll never know it. That answer satisfies no one, however.

There are deeper explanations. Perhaps alien civilisations appear and disappear in a galactic blink of an eye, destroying themselves long before they become capable of colonising new planets. Or maybe life very rarely gets started even when conditions are perfect.

If we cannot answer these kinds of questions by looking out, might it be possible to get some clues by looking in? Life arose only once on Earth, and if a sample of one were all we had to go on, no grand conclusions could be drawn. But there is more than that. Looking at a vital ingredient for life – energy – suggests that simple life is common throughout the universe, but it does not inevitably evolve into more complex forms such as animals. I might be wrong, but if I’m right, the immense delay between life first appearing on Earth and the emergence of complex life points to another, very different explanation for why we have yet to discover aliens.

Living things consume an extraordinary amount of energy, just to go on living. The food we eat gets turned into the fuel that powers all living cells, called ATP. This fuel is continually recycled: over the course of a day, humans each churn through 70 to 100 kilograms of the stuff. This huge quantity of fuel is made by enzymes, biological catalysts fine-tuned over aeons to extract every last joule of usable energy from reactions.

The enzymes that powered the first life cannot have been as efficient, and the first cells must have needed a lot more energy to grow and divide – probably thousands or millions of times as much energy as modern cells. The same must be true throughout the universe.

This phenomenal energy requirement is often left out of considerations of life’s origin. What could the primordial energy source have been here on Earth? Old ideas of lightning or ultraviolet radiation just don’t pass muster. Aside from the fact that no living cells obtain their energy this way, there is nothing to focus the energy in one place. The first life could not go looking for energy, so it must have arisen where energy was plentiful.

Today, most life ultimately gets its energy from the sun, but photosynthesis is complex and probably didn’t power the first life. So what did? Reconstructing the history of life by comparing the genomes of simple cells is fraught with problems. Nevertheless, such studies all point in the same direction. The earliest cells seem to have gained their energy and carbon from the gases hydrogen and carbon dioxide. The reaction of H2 with CO2 produces organic molecules directly, and releases energy. That is important, because it is not enough to form simple molecules: it takes buckets of energy to join them up into the long chains that are the building blocks of life.

A second clue to how the first life got its energy comes from the energy-harvesting mechanism found in all known life forms. This mechanism was so unexpected that there were two decades of heated altercations after it was proposed by British biochemist Peter Mitchell in 1961.

Universal force field

Mitchell suggested that cells are powered not by chemical reactions, but by a kind of electricity, specifically by a difference in the concentration of protons (the charged nuclei of hydrogen atoms) across a membrane. Because protons have a positive charge, the concentration difference produces an electrical potential difference between the two sides of the membrane of about 150 millivolts. It might not sound like much, but because it operates over only 5 millionths of a millimetre, the field strength over that tiny distance is enormous, around 30 million volts per metre. That’s equivalent to a bolt of lightning.

Mitchell called this electrical driving force the proton-motive force. It sounds like a term from Star Wars, and that’s not inappropriate. Essentially, all cells are powered by a force field as universal to life on Earth as the genetic code. This tremendous electrical potential can be tapped directly, to drive the motion of flagella, for instance, or harnessed to make the energy-rich fuel ATP.

However, the way in which this force field is generated and tapped is extremely complex. The enzyme that makes ATP is a rotating motor powered by the inward flow of protons. Another protein that helps to generate the membrane potential, NADH dehydrogenase, is like a steam engine, with a moving piston for pumping out protons. These amazing nanoscopic machines must be the product of prolonged natural selection. They could not have powered life from the beginning, which leaves us with a paradox.

[div class=attrib]Read the entire article following the jump.[end-div]

[div class=attrib]Image: Transmission electron microscope image of a thin section cut through an area of mammalian lung tissue. The high magnification image shows a mitochondria. Courtesy of Wikipedia.[end-div]

Idea Soup

On Being a Billionare For a Day

New York Times writer Kevin Roose recently lived the life of a billionaire for a day. His report while masquerading as a member of the 0.01 percent of the 0.1 percent of the 1 percent makes for fascinating and disturbing reading.

[div class=attrib]From the New York Times:[end-div]

I HAVE a major problem: I just glanced at my $45,000 Chopard watch, and it’s telling me that my Rolls-Royce may not make it to the airport in time for my private jet flight.

Yes, I know my predicament doesn’t register high on the urgency scale. It’s not exactly up there with malaria outbreaks in the Congo or street riots in Athens. But it’s a serious issue, because my assignment today revolves around that plane ride.

“Step on it, Mike,” I instruct my chauffeur, who nods and guides the $350,000 car into the left lane of the West Side Highway.

Let me back up a bit. As a reporter who writes about Wall Street, I spend a fair amount of time around extreme wealth. But my face is often pressed up against the gilded window. I’ve never eaten at Per Se, or gone boating on the French Riviera. I live in a pint-size Brooklyn apartment, rarely take cabs and feel like sending Time Warner to The Hague every time my cable bill arrives.

But for the next 24 hours, my goal is to live like a billionaire. I want to experience a brief taste of luxury — the chauffeured cars, the private planes, the V.I.P. access and endless privilege — and then go back to my normal life.

The experiment illuminates a paradox. In the era of the Occupy Wall Street movement, when the global financial elite has been accused of immoral and injurious conduct, we are still obsessed with the lives of the ultrarich. We watch them on television shows, follow their exploits in magazines and parse their books and public addresses for advice. In addition to the long-running list by Forbes, Bloomberg now maintains a list of billionaires with rankings that update every day.

Really, I wondered, what’s so great about billionaires? What privileges and perks do a billion dollars confer? And could I tap into the psyches of the ultrawealthy by walking a mile in their Ferragamo loafers?

At 6 a.m., Mike, a chauffeur with Flyte Tyme Worldwide, picked me up at my apartment. He opened the Rolls-Royce’s doors to reveal a spotless white interior, with lamb’s wool floor mats, seatback TVs and a football field’s worth of legroom. The car, like the watch, was lent to me by the manufacturer for the day while The New York Times made payments toward the other services.

Mike took me to my first appointment, a power breakfast at the Core club in Midtown. “Core,” as the cognoscenti call it, is a members-only enclave with hefty dues — $15,000 annually, plus a $50,000 initiation fee — and a membership roll that includes brand-name financiers like Stephen A. Schwarzman of the Blackstone Group and Daniel S. Loeb of Third Point.

Over a spinach omelet, Jennie Enterprise, the club’s founder, told me about the virtues of having a cloistered place for “ultrahigh net worth individuals” to congregate away from the bustle of the boardroom.

“They want someplace that respects their privacy,” she said. “They want a place that they can seamlessly transition from work to play, that optimizes their time.”

After breakfast, I rush back to the car for a high-speed trip to Teterboro Airport in New Jersey, where I’m meeting a real-life billionaire for a trip on his private jet. The billionaire, a hedge fund manager, was scheduled to go down to Georgia and offered to let me interview him during the two-hour jaunt on the condition that I not reveal his identity.

[div class=attrib]Read the entire article after the Learjet.[end-div]

[div class=attrib]Image: Waited On: Mr. Roose exits the Rolls-Royce looking not unlike many movers and shakers in Manhattan. Courtesy of New York Times.[end-div]

Idea Soup

A Philosoper On Avoiding Death

Below we excerpt a brilliant essay by Alex Byrne summarizing his argument that our personal survival is grossly over-valued. But, this should not give future teleportation engineers chance to pause. Alex Byrne is a professor of philosophy at MIT.

[div class=attrib]From the Boston Review:[end-div]

Star Trek–style teleportation may one day become a reality. You step into the transporter, which instantly scans your body and brain, vaporizing them in the process. The information is transmitted to Mars, where it is used by the receiving station to reconstitute your body and brain exactly as they were on Earth. You then step out of the receiving station, slightly dizzy, but pleased to arrive on Mars in a few minutes, as opposed to the year it takes by old-fashioned spacecraft.

But wait. Do you really step out of the receiving station on Mars? Someone just like you steps out, someone who apparently remembers stepping into the transporter on Earth a few minutes before. But perhaps this person is merely your replica—a kind of clone or copy. That would not make this person you: in Las Vegas there is a replica of the Eiffel Tower, but the Eiffel Tower is in Paris, not in Las Vegas. If the Eiffel Tower were vaporized and a replica instantly erected in Las Vegas, the Eiffel Tower would not have been transported to Las Vegas. It would have ceased to exist. And if teleportation were like that, stepping into the transporter would essentially be a covert way of committing suicide. Troubled by these thoughts, you now realize that “you” have been commuting back and forth to Mars for years . . .

So which is it? You are preoccupied with a question about your survival: Do you survive teleportation to Mars? A lot hangs on the question, and it is not obvious how to answer it. Teleportation is just science fiction, of course; does the urgent fictional question have a counterpart in reality? Indeed it does: Do you, or could you, survive death?

Teeming hordes of humanity adhere to religious doctrines that promise survival after death: perhaps bodily resurrection at the Day of Judgment, reincarnation, or immaterial immortality. For these people, death is not the end.

Some of a more secular persuasion do not disagree. The body of the baseball great Ted Williams lies in a container cooled by liquid nitrogen to -321 degrees Fahrenheit, awaiting the Great Thawing, when he will rise to sign sports memorabilia again. (Williams’s prospects are somewhat compromised because his head has apparently been preserved separately.) For the futurist Ray Kurzweil, hope lies in the possibility that he will be uploaded to new and shiny hardware—as pictures are transferred to Facebook’s servers—leaving his outmoded biological container behind.

Isn’t all this a pipe dream? Why isn’t “uploading” merely a way of producing a perfect Kurzweil-impersonator, rather than the real thing? Cryogenic storage might help if I am still alive when frozen, but what good is it after I am dead? And is the religious line any more plausible? “Earth to earth, ashes to ashes, dust to dust” hardly sounds like the dawn of a new day. Where is—as the Book of Common Prayer has it—the “sure and certain hope of the Resurrection to eternal life”? If a forest fire consumes a house and the luckless family hamster, that’s the end of them, presumably. Why are we any different?

Philosophers have had a good deal of interest to say about these issues, under the unexciting rubric of “personal identity.” Let us begin our tour of some highlights with a more general topic: the survival, or “persistence,” of objects over time.

Physical objects (including plants and animals) typically come into existence at some time, and cease to exist at a later time, or so we normally think. For example, a cottage might come into existence when enough beams and bricks are assembled, and cease to exist a century later, when it is demolished to make room for a McMansion. A mighty oak tree began life as a tiny green shoot, or perhaps an acorn, and will end its existence when it is sawn into planks.

The cottage and the oak survive a variety of vicissitudes throughout their careers. The house survived Hurricane Irene, say. That is, the house existed before Irene and also existed after Irene. We can put this in terms of “identity”: the house existed before Irene and something existed after Irene that was identical to the house.

[div class=attrib]Read the entire essay here.[end-div]