Friday, 3 December 2010

Chasing The Sun

The sun shines on a solar quest

Chasing The Sun: The epic story of the star that gave us life by Richard Cohen

Independent, 3 December 2010


A Chinese-made portable solar-powered lamp and charger was the final object chosen by Neil MacGregor, director of the British Museum, in his A History of the World in 100 Objects. It was a choice that few would have predicted, but once its solar panel captures and stores the energy of eight hours of sunshine, this 21st-century lamp converts it into 100 hours of light to be used whenever and wherever needed. "The power of the Sun seems a good place to end this global history," said MacGregor, "because solar energy is a dream of the future that echoes the oldest and most universal of human myths, that of the life-giving Sun."

Richard Cohen has produced an encyclopaedia of a book that could almost serve as a companion to MacGregor's landmark series – an alternative history of the world told through humanity's relationship with a single object.

He begins with the myth of the Sun as the god Inti, of the tribes of Peru and northern Chile, who descended into the ocean every evening, swam back to the east, then reappeared, refreshed by his bath. The Hopi of Arizona claim that they made the Sun by throwing up a buckskin shield along with a fox's coat and a parrot's tail, to make the colours of sunrise and sunset.

"The Sun is 32,000 light years from the centre of its galaxy of a hundred billion stars, which it orbits at about 155 miles a second, taking about 200 million years to complete a revolution," reports Cohen. The Sun has been active for 4.6 billion years and a single particle of light, a photon, from its core takes 150,000 years to reach space. Every second, about five million metric tonnes of mass are converted into nuclear energy: equivalent to the detonation of 90,000 million one-megaton hydrogen bombs. The numbers are mind-boggling, but this constant blast of nuclear reactions pushes energy to the surface, releasing it as light and heat.

The Earth receives more of this energy in just 45 minutes than its inhabitants consume in a year. About 35 per cent is reflected back into space by clouds and the atmosphere absorbs another 19 per cent. This still leaves 12,000 times as much energy as used by all man-made devices.

Effectively harnessing the Sun is not just a modern ambition. The Greeks in the third century BC used "burning mirrors" to focus sunlight on enemy warships. Archimedes, so legend has it, deployed such mirrors in 212BC to defend Syracuse from a blockading Roman fleet by burning the enemy's sails.The Romans were the first to build greenhouses. In the sixth century, the Emperor Justinian passed a law protecting public and domestic sunrooms from the erection of buildings that obstructed light; a 1,000 years later, Leonardo da Vinci proposed using a giant mirror as a commercial source of heat.

Like some latter-day Victorian species hunter who travels the globe collecting new specimens, Cohen spent eight years chasing the Sun across 18 countries and six continents. He began with a climb to the top of Mount Fuji to watch the sunrise on the summer solstice and ended in a sunset viewed from a boat on the Ganges at Varanasi.

Among other trips, Cohen recounts seeing an eclipse on the Antarctic ice. He visits the Arctic city of Tromso in Norway, which for ten weeks each year receives virtually no sunlight (a period the locals call "the dark times"), to investigate how we react to the loss of light.

Among Cohen's treasure-trove of solar miscellanea is the "sunspot cycle" in modern economics, the story of sundials and calendars from Julius Caesar to Pope Gregory VII, the introduction of daylight saving time in 1916 as a wartime economic measure, and a brief history of navigation and cartography. He shows how the Babylonians were the first to record the Sun's movements in detail, while the Greeks went further, inquiring into its size, shape, and distance from the Earth.

Occasionally Cohen's passion for all things solar gets the better of him, as when he suggests that the lingams of Hindu temple domes are "purposely imitated in the design of nuclear-reactor cones, the latest tribute to the Sun's potency". Yet he can be forgiven, as we learn how artists from the Renaissance to Hockney have depicted the Sun, or of Shakespeare's enthusiasm for suntans. We see why Galileo recorded his discovery of sunspots in code, why Matisse rushed out of his dying wife's bedroom, why Wagner hated the Sun and Mozart loved it.

All things come to an end, and Cohen devotes a chapter to the death of the Sun. As I read it I remembered the first part of a poem by Francis William Bourdillon:

The night has a thousand eyes,
And the day but one;
Yet the light of the bright world dies
With the dying of the sun.

Monday, 22 November 2010

Species Seekers

A Breed of their own

The Species Seekers: Heroes, Fools and the Mad Pursuit of Life on Earth by Richard Conniff

Financial Times, 20-21 November 2010

‘Our perfect naturalist,’ wrote the English clergyman, naturalist and novelist Charles Kingsley in 1855, “should be strong in body; able to haul a dredge, climb a rock, turn a boulder, walk all day … he should know how to swim for his life, to pull an oar, sail a boat, and ride the first horse which comes to hand; and, finally, he should be a thoroughly good shot, and a skilful fisherman; and, if he go far abroad, be able on occasion to fight for his life.’

Amid the tales of adventure and hardship vividly told by the American science writer Richard Conniff in this marvelous book, most of those naturalists who made it their mission to travel the globe in of search glory and new species were far from perfect. But as he captures the mania for collecting and cataloguing the natural world in the 18th and 19th centuries, Conniff shows that these daredevil amateurs played an invaluable ‘part in building a great and permanent body of knowledge’.

What does it mean to discover a species? Surely local people had known most of these species for many years before they were ‘discovered’. Discovery, explains Conniff, isn’t just a matter of being the first person to lay eyes on an animal, plant or insect. You must recognize that there’s something different about it and explain in print just how and why it’s different. That requires some scheme of classification.

At the beginning of the 18th century, naturalists knew only a few thousand species, and sometimes could not even distinguish plants from animals. That changed in 1735 when the Swedish botanist Carolus Linnaeus published his system for identifying and classifying species.

Armed with the Linnaean system, guns, nets, collecting boxes and an almost missionary sense of purpose, species seekers went everywhere, from the Namib Desert to the Great Barrier Reef, and brought back creatures that even the authors of medieval bestiaries could hardly have imagined.

Naturalists were often caught up in the business of conquest and colonization, using natural history to advance their own careers and to remake the world on European lines. Yet many of us are alive today, for instance, because naturalists identified obscure species that later turned out to cause malaria, yellow fever, typhus and other epidemic diseases.

Modern species seekers still aim to catalogue every species on Earth, even though the tally is nearing 2m, and new ones are found daily. In 2003, the eminent American zoologist E. O. Wilson proposed the Encyclopedia of Life, a web-based project with a page for every species within 25 years. But as Wilson acknowledged at the time, ‘the truth is that we do not know how many species of organisms exist on Earth even to the nearest order of magnitude.’ He thought the final count would be about 10m. Others believe it could be 50m or even 100m - numbers that Conniff’s heroes and fools could not have imagined. We still live in the great age of discovery and this is the story of how it began.

Friday, 19 November 2010

Sleights of Mind

A fascinating look at a new branch of cognitive research: "neuromagic"

Sleights of Mind: What the neuroscience of magic reveals about our everyday deceptions by Stephen L Macnik, Susana Martinez-Conde and Sandra Blakeslee

New Scientist, 20 November 2010


MAGIC, it mystifies and captivates us. We shake our heads in disbelief as coins are conjured out of thin air, as cards are mysteriously summoned from a pack, and as the magician's assistant vanishes before our eyes. Of course, there is no such thing as "magic", so how does magic work? It's a question that neuroscientists like Stephen Macknik and Susana Martinez-Conde are trying to answer. In the process they have conjured up a new branch of cognitive research called neuromagic.

From misdirection and the magical practice of "forcing", to mirror neurons and synaptic plasticity, Sleights of Mind is a spellbinding mix of magic and science. The authors invite us to sip this heady potion as they show us how understanding the myriad ways in which the brain is deceived by magic may solve some of the mysteries surrounding how it works.

“Magic tricks fool us because humans have hard-wired processes of attention and awareness that are hackable,” say the authors. Magicians use your mind’s intrinsic properties against you. In a magical feat of their own, the authors persuaded magicians such as James Randi and Teller from the Las Vegas headline act Penn and Teller to deconstruct tricks so that Macknik and Martinez-Conde could later attempt to reconstruct what is going on inside your head “as you are suckered”.

Magic, say the neuroscientists, could reveal how the brain functions in everyday situations such as shopping. However, it is a stretch to believe, as the authors do, that if you’ve bought an expensive item that you never intended to buy, then you were probably a victim of the “illusion of choice”, a technique magicians use to rob their dupes of genuine choice.

The magician toys with us when he appears to put a coin into his right hand, closes it, waves his left over it, and then opens the right. The coin, which we feel must still be there, has “vanished”. He makes us experience the impossible by disrupting the expected relationship between a cause and its effect.

What we see, hear, and feel is based on what we expect to see, hear and feel due to our experiences and memories. When these expectations are violated the brain takes more time to process data or our attention focuses on the violation. Success or failure for the magician relies on his skill in diverting our attention away from the method and towards the magical effect.

Great magicians, through countless hours of practice, manipulate our attention, memory and causal inferences using a bewildering combination of visual, auditory and tactile methods. The greatest magic show on earth, though, is the one happening in your brain.

Thursday, 4 November 2010

Neutrino

Ghost Particle

Neutrino by Frank Close

New Scientist, 6 November 2010


For a moment in the late 1920s, Niels Bohr considered the unthinkable: abandoning the notion of conservation of energy. He wasn't calling for its wholesale rejection, only that it be disregarded whenever a neutron decayed into a proton and an electron, as some energy appeared to go missing along the way.

Wolfgang Pauli, who was wont to damn poor ideas as "not even wrong", came up with a solution he called "a terrible thing" - an unknown particle to account for the missing energy. Since it had to be electrically neutral with little or no mass, it was called the neutrino, the "little neutral one".

In this short and informative book, Frank Close recalls those who had the ingenuity and patience to catch and understand this elusive particle that barely interacts with other matter. Their successors are hunting neutrinos left over from the big bang, and no one knows what story these relics will tell.

Friday, 29 October 2010

Did You See The Gorilla?

Tehelka, 6 November 2010
Click the page to read the article.

Thursday, 28 October 2010

The Naked Scientist

Bare Essentials

The Naked Scientist by Chris Smith

New Scientist, 30 October 2010


If you are not a fan of Jamie Oliver, aka the Naked Chef, then the title alone may be enough to put you off this book. But resist the temptation to judge it by its cover. This is science packaged as light entertainment, with flash-facts and bite-sized stories ranging from how fish help pollinate flowers to why booze makes us drunk. Among the more fascinating entries are a study that found that people are less likely to remember brands advertised during violent and sexually explicit programmes, and the possibility that eating curry could help ward off Alzheimer's.

The Naked Scientist is the alter ego of University of Cambridge virologist Chris Smith, who wants to "strip down science to the bare essentials and expose you to what it really is - addictively enjoyable, interesting and occasionally a bit naughty". With Christmas looming, and in search of an audience, Smith bares just enough to pull it off.

Sunday, 17 October 2010

Merchants of Doubt

A lot of hot air from the sceptics

Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming by Naomi Oreskes and Erik M Conway

Independent, 18 October 2010


Public scepticism about climate change is on the rise. The shift is due in part to the publication of the hacked emails of the University of East Anglia's "climategate" scientists. Now climatologists have to live with the fact that most people simply don't trust them. Merchants of Doubt, by two historians of science, may help restore some trust by showing that science is rarely black and white, and how its shades of grey have sometimes been distorted by a few willing hands.

Writing before "climategate", Naomi Oreskes and Erik Conway believe that "We all need a better understanding of what science really is...and how to separate it from the garbage." They tell the story of how for half a century, a small group of scientists in America collaborated with think-tanks and corporations in campaigns to discredit scientific research by creating doubt and manipulating debate.

Manufacturing doubt as an effective corporate strategy was first developed by the American tobacco industry. Determined to stop any government regulation in the face of scientific evidence linking tobacco to lung cancer, the cigarette-makers created the Council for Tobacco Research to discredit the scientists and dispute their findings. "Doubt is our product," boasted a now infamous 1969 industry memo. Doubt would shield the tobacco industry from litigation and regulation for decades to come.

The so-called "Tobacco Strategy" was used to "maintain the controversy" by promoting claims contrary to research. The peddlers of doubt insisted that scientists were wrong about the risks of Ronald Reagan's Strategic Defence Initiative, and that acid rain was caused by volcanoes. They would dismiss global warming by claiming, in turn, that there was none; if there was, it was just natural variation; finally, it didn't matter because humans would adapt. Aided by a complicit media, these claims generated the illusion of genuine scientific debate when there was none at all.

No scientific conclusion can ever be proven with certainty, but it is no more a "belief" to say that the Earth is heating up than to say that continents move or that germs cause disease. Oreskes and Conway warn that, "without some degree of trust in our designated experts we are paralyzed".

Saturday, 16 October 2010

Cycles of Time

Now and Then

Cycles of Time: An Extraordinary New View of the Universe by Roger Penrose

Guardian, 16 October 2010

When I first encountered the work of MC Escher, I couldn't understand how he managed to depict the seemingly impossible. I was nine, and the two pieces that puzzled me were Waterfall and Ascending and Descending. In the first, water at the bottom of a waterfall flows along a channel back to the top without defying gravity in a never-ending cycle. The second is even more striking, with one set of monks climbing an endless staircase while another group walk down it without either ever getting any higher or lower. Years later I learnt that both works were inspired by Roger Penrose.

As a student in 1954, Penrose was attending a conference in Amsterdam when by chance he came across an exhibition of Escher's work. Soon he was trying to conjure up impossible figures of his own and discovered the tri-bar – a triangle that looks like a real, solid three-dimensional object, but isn't. Together with his father, Penrose went on to design a staircase that simultaneously loops up and down. An article followed and a copy was sent to Escher. Completing a cyclical flow of creativity, the Dutch master of geometrical illusions was inspired to produce his two masterpieces.

Doing what most find impossible has long been Penrose's stock in trade in mathematics and physics, even when it comes to publishing. His previous book, The Road to Reality, was a 1,049-page bestseller, although it was mostly a textbook. Penrose doesn't do "popular", as he peppers his books with equation after equation in defiance of the publishing maxim that each one cuts sales in half. By that reckoning Cycles of Time will have about four readers, though it's probably destined to be another bestseller. As Penrose puts forward his truly Extraordinary New View of the Universe, that the big bang is both the end of one aeon and the beginning of another in an Escheresque endless cycling of time, he outlines the prevailing orthodoxy about the origins of the cosmos.

In the late 20s it was discovered that the light from distant galaxies was stretched towards the red end of the visible spectrum. This redshift was found to be greater the further away the galaxy was, and was accepted as evidence of an expanding universe. This inevitably led theorists to extrapolate backwards to the big bang – the moment of its birth some 13.7bn years ago, when space and time exploded into being out of a single point, infinitely hot and dense, called a singularity. That at least was the theory, with little more to back it up until 1964, when two American scientists discovered "cosmic background radiation" – the faint echo of the big bang. In the decades since, further evidence has accumulated and theoretical refinements made to accommodate it. Yet in recent years a few physicists have challenged the big bang model by daring to ask and answer questions such as: was the big bang the beginning of the universe?

Traditionally such questions have been dismissed as meaningless – space and time were created at the big bang; there simply was no "before". Although it's possible to work out in incredible detail what happened all the way back to within a fraction of a second of the big bang, at the moment itself the theory of general relativity breaks down, or as Penrose puts it: "Einstein's equations (and physics as a whole, as we know it) simply 'give up' at the singularity." However, he believes we should not conclude from this that the big bang was the beginning of the universe.

Acknowledging that he's not the first to think such heretical thoughts, Penrose looks at earlier "pre-big bang proposals". Finding them "fanciful", Penrose looked anew at the big bang, because of an unsolved mystery at its heart involving the Second Law of Thermodynamics. One of the most fundamental in all of physics, it simply says that the amount of disorder, something that physicists label "entropy", increases with the passage of time. Herein lies the mystery for Penrose. The instant after the big bang, "a wildly hot violent event", must have been one of maximum entropy. How can entropy therefore increase? Penrose thinks he has the answer; there must be a pre-big bang era that ensures that entropy is low at the birth of the universe. And here's how.

In what Penrose calls "conformal cyclic cosmology", the beginning and the end of the universe are in effect the same, since these two phases of its evolution contain only massless particles. Between now and a far off distant future, everything from the tiniest particles to biggest galaxies will have been eaten by black holes. They in turn lose energy in the form of massless particles and slowly disappear. As one black hole after another vanishes the universe loses "information". Since information is linked to entropy, the entropy of the universe decreases with the demise of each black hole.

The strangest thing about massless particles is that for them there is no such thing as time. There is no past or present, only "now", and it stretches for all eternity – but since there is no tick of the clock, what eternity? With some mind-numbing maths, Penrose argues that as time ends in the era of massless particles, the fate of our universe can actually be reinterpreted as the big bang of a new one: "Our universe is what I call an aeon in an endless sequence of aeons." Escher would have approved.

Thursday, 14 October 2010

The Amazing Story of Quantum Mechanics

Captain Quantum

The Amazing Story of Quantum Mechanics: A math-free exploration of the science that made our world by James Kakalios

New Scientist, 16 October 2010


“EXTRAVAGANT Fiction Today, Cold Fact Tomorrow” was the bold claim of Amazing Stories, the first American magazine devoted to science fiction. Beginning in the 1930s, these sci-fi pulps and comics envisaged that by the year 2000 we would be living in a world with domed underwater cities and travelling in flying cars and by jetpacks. Instead we have mobile phones, laptops and DVDs.

The predictions were off, says James Kakalios, because implicit in the promise of flying cars is the availability of lightweight power supplies capable of producing enormous quantities of energy. In fact, the capacity of batteries to act as reservoirs of energy is limited by the chemical and electrical properties of atoms – and we cannot change the physics of atoms.

This is Kakalios’s cue to explain the key concepts of quantum mechanics and show how these ideas account for the properties of metals, insulators and semiconductors – and how they underlie the magnetic properties of atoms that let us store vast amounts of data on computer hard drives and build MRI scanners that can see inside the human body.

The physicists who developed quantum theory and the fans of sci-fi pulps had one thing in common, says Kakalios, and that is a willingness to suspend disbelief as they accepted the impossible as real. Three such quantum facts were: light is an electromagnetic wave that is actually composed of chunks of energy; matter is composed of particles that exhibit a wave-like nature; and both light and matter have a property called spin that can only have certain values.

Having provided the reader with these counter-intuitive notions, Kakalios looks at the problems they solved. To help explain Planck’s discovery of the quantum, the photoelectric effect, the quantum atom, wave-particle duality, Schrödinger’s wave equation, the probabilistic interpretation of the wave function, the uncertainty principle and more besides, comic-loving Kakalios enlists a legion of superheroes, from Superman to Dr Manhattan.

In addition to his bright-blue appearance, Jon Osterman aka Dr Manhattan, appears to have gained control of his quantum- mechanical wave function. This, the starting point for Kakalios’s highly readable presentation of quantum ideas, give him the ability to alter his size at will, to teleport himself and others from one place to another, and to experience the past, present and future simultaneously.

The scientist as a world- changing hero is an apt description for the physicists who developed quantum mechanics, Kakalios believes. He has a point. The discoveries by a handful of physicists back in the 1920s and 1930s of the rules that govern how atoms interact with light and each other continue to shape and change the world we live in.

Galileo

Galileo: Watcher of the Skies by David Wootton

Sunday Telegraph, 10 October 2010


It is a little known fact that in 1532 Copernicus’s sun-centred solar system was presented to an audience in the Vatican. Given the storm that was to come, it is barely believable that the then pope, Leo X, afterwards sent a note of encouragement to Copernicus as the Polish priest laboured to finish his book. On the Revolutions of the Heavenly Spheres was published in 1543 and Copernicus, so the story goes, held the first copy to come off the press just hours before he died. As long as his heliocentric model was presented as hypothetical, the Vatican was unconcerned by Copernicanism. One man changed all that.

Born in February 1564, Galileo Galilei initially set out to be a doctor before switching to mathematics – much to the displeasure of his father. It is unlikely that, according to the legend, he ever dropped balls from the leaning tower of Pisa as he investigated the motion of falling bodies and discovered that all objects fall at the same rate, contradicting what everybody believed since Aristotle.

When, in 1609, he learnt of the invention of the telescope by a Dutch spectacle maker, Galileo quickly constructed his own. Within a matter of months he had transformed it from a toy into an instrument of scientific discovery and he found that the Milky Way was not a streak across the sky but a multitude of stars; that the Moon had mountains and valleys; and he observed the phases of Venus and the spots on the Sun.

'For Galileo, seeing was believing,’ says the historian David Wootton. Yet he argues persuasively in this well researched, intellectual biography that Galileo was a Copernican long before his discovery of the moons of Jupiter proved that not all heavenly bodies revolved around the Earth. In March 1610, Galileo published his discoveries in the aptly titled book, The Starry Messenger. All 550 copies were sold within a week and soon the 46 year-old was Europe’s most celebrated natural philosopher.

Faced with the Reformation, the Catholic Church was increasingly less tolerant of dissent. In 1616, Galileo went to Rome after a letter he wrote was brought to the attention of the Holy Office of the Inquisition. In it Galileo argued that although the Bible is the word of God, it is adapted to human capacities. Nature, however, is 'inexorable and immutable’. So, when it comes to certain questions, direct knowledge of nature must always take priority over whatever the Bible may have to say on the subject. And the answer to one of those questions was that it is the Earth that moves around the Sun and not the other way round.

Wootton does a good job of untangling who said what to whom and when in Galileo’s dealings with the Inquisition. To cut a long story short, Galileo was given a formal warning that forbade him from holding, teaching or defending Copernicanism. To complicate matters, around the same time, in March 1616, the Vatican banned all books that held Copernicanism to be true.

Then, in a surprising turn of events, in 1623 Maffeo Barberini, an old friend of Galileo’s, was elected pope. Urban VIII allowed Galileo to re-enter the somewhat muted debate on Copernicanism. Before long, argues Wootton, intellectual ambition and vanity led Galileo to stake everything on facing down his opponents in his book Dialogue on the Two Chief World Systems. In April 1633, Galileo was summoned before the Inquisition and held firm that, although in the Dialogue he discussed Copernicanism, he did not defend it, and he denied any knowledge of the injunction of 1616 not even to do that.

It was at this point that the prosecutor played his trump card – a report that Galileo was guilty in an earlier book of denying transubstantiation. It was a charge that, if proven, implied that Galileo was not a Catholic but a Protestant. While admitting to piling 'conjecture upon conjecture’, Wootton goes further than any enforcer of the Inquisition and accuses Galileo of not being a Christian at all.

Galileo died in 1642, a prisoner of the Inquisition. In 1992, the Catholic Church apologised for its treatment of the secular saint. Only God knows what Leo X would have made of it all.