Saturday, 18 September 2010


Arabic Heights

Pathfinders: The Golden Age of Arabic Science by Jim Al-Khalili

The Times, 18 September 2010

Stockholm, December 1979. Ten men wait to receive their Nobel prizes from the King of Sweden. Nine are wearing white tie and tails. Abdus Salam, a devout Muslim, stands out in a turban and traditional Punjabi clothes. The Pakistani physicist is being honoured for his part in formulating the electroweak theory that unites electromagnetism and the weak nuclear force. ‘There is no doubt in my mind that his work places him as the greatest physicist of the Islamic world for a thousand years,’ says Jim Al-Khalili, Iraqi-born physicist-cum-writer.

For many non-Muslims, the term ‘Islam’ evokes a ‘negative stereotype that contrasts with our Western, secular, rational, tolerant and enlightened society’, says Al-Khalili. This captivating book is his timely reminder of the debt owed by the West to the intellectual achievements of Arab, Persian and Muslim scholars, a thousand years before Salam got his Nobel prize, when the roles were reversed.

Al-Khalili has long wanted to tell the tale of the ‘golden age of Arabic science’ that began in the late 8th century and lasted for more than 500 years. Since there is no such thing as ‘Jewish science’ or ‘Christian science’, Al-Khalili explains that by ‘Arabic science’ he means the remarkable body of work produced in Arabic, the lingua franca of science and much else as Europe slumbered through its Dark Ages.

The Koran was the first book written in Arabic, and much effort was spent studying and interpreting it. The wealth and power of the growing Islamic empire made it possible for the Abbasid caliphs to promote an ever-expanding sphere of academic inquiry that had been lost since the glory days of Greek Alexandria. Advances in maths, astronomy, physics, chemistry, medicine and the flourishing of philosophy that took place, first in Baghdad and then across the Islamic world, all have their origins in what historians call the translation movement.

Thanks to the practical benefits it brought in finance, agriculture, engineering and health, the translation movement was a 200-year process during which much of the wisdom of the Greeks, Persians and Indians was translated into Arabic. These translations helped produce a culture of scholarship that became self-sustaining and formed part of a wider quest for knowledge that evolved into a new tradition of intellectual exploration that sparked the beginning of an age of scientific progress. A 9th-century caliph of Baghdad created the House of Wisdom, a centre of learning that some say was home to 400,000 books – at a time when the best European libraries held no more than a few dozen.

In 711, Muslims crossed into Spain and so began almost eight centuries of Islamic influence in Andalusia. Just as Baghdad had been the epicentre of the translation movement from Greek into Arabic, so cities like Córdoba and Toledo became the centres of translation of the great Arabic texts into Latin. One of the first scholars to study these was Gerbert d’Aurillac, a 10th-century French monk. He would later become the first Christian scholar to carry Arabic learning across the Pyrenees. It seems fitting that the man who would later become Pope Sylvester II introduced Christian Europe to the science of the Islamic empire.

Al-Khalili argues that the scientific revolution could not have taken place without the advances of the medieval Islamic world. Ibn al-Haytham dominated the field of optics long before Newton and used the scientific method 600 years before Francis Bacon even thought about it. Abdus Salam, who died in 1996, named some of the giants of Arabic science in his Nobel lecture: al-Biruni, al-Razi, Ibn Sina, Jabir, and al-Khwarizmi. If you want to know what these men did, read this fascinating book and let Al-Khalili tell you their stories.

‘We should not be ashamed to recognise truth and assimilate it, from whatever quarter it may reach us, even though it may come from earlier generations and foreign peoples,’ wrote Ya’qub ibn Ishaq al-Kindi, one of the great polymaths of the ‘golden age’. ‘For the seeker after truth there is nothing of more value than truth itself; it never cheapens or debases the seeker, but ennobles and elevates him.’

Friday, 10 September 2010

The Grand Design

Theories of everything: Has cosmic science written its last word?

Independent, 10 September 2010

God is dead," declared Friedrich Nietzsche, but few listened or cared. "It is not necessary to invoke God to light the blue touch paper and set the universe going," announced Stephen Hawking last week, and it was picked up by the world's media. For over 20 years earlier, the world's most famous scientist had ended his phenomenal bestseller A Brief History of Time with the arresting conclusion that "If we discover a complete theory, it would be the ultimate triumph of human reason - for then we should know the mind of God."

Why is there something rather than nothing? Why do we exist? Why this particular set of laws and not some other? It is these "ultimate questions of life" that Hawking's now sets out to answer, with the help of the American physicist and science writer Leonard Mlodinow, in his fascinating new book The Grand Design (Bantam, £18.99). Philosophers have traditionally tackled such questions, while most physicists have stayed well clear from addressing the "why" of things and concentrated instead on the "how".

Not any more. "To understand the universe at the deepest level," says Hawking, "we need to know not only how the universe behaves, but why." He believes that "philosophy is dead" because it failed to keep up with the latest developments, especially in physics.

For it is possible to answer these questions purely within the realm of science and without resorting to God. And the answers hinge on a candidate for a theory of everything called M-theory, "if it indeed exists", the authors admit. Unfortunately, no one seems to know what "M" stands for; it could be "master", "miracle" or "mystery".

The story of M-theory could be said to begin with the desire of physicists to unify and simplify. Just as ice, water and steam are different manifestations of water, in 1864 James Clerk Maxwell showed that electricity and magnetism were likewise different manifestations of the same underlying phenomenon - electromagnetism. He managed to encapsulate the disparate the behaviour of electricity and magnetism into a set of four elegant mathematical equations. Using these equations, Maxwell was able to make the startling prediction that electromagnetic waves travelled at the speed of light, approximately 670 million miles per hour. Light was a form of electromagnetic radiation. Maxwell's unification of electricity, magnetism and light was the crowning achievement of 19th-century physics.

In the 20th century, to go with gravity and electromagnetism, physicists discovered two new forces - the weak, which is responsible for radioactivity, and the strong that binds together, for example, the nucleus of an atom. They believed that these four forces, which appeared so different, would be reunited a single all-encompassing theory of everything.With exception of general relativity, Einstein's theory of gravity, it's possible to "quantize" the other three forces, since quantum mechanics deals with the atomic and sub-atomic domain. In effect, we have three trains running on the same-sized track.

Unfortunately, Einstein's gravity train was running on a completely incompatible track. Yet the impulse for unity and simplicity is so strong that theorists have pursued a quantum theory of gravity, without success, for decades. Then in the 1980s there appeared a new theory that looked promising - superstrings.

The theory assumes that all observed particles are different manifestations of the same fundamental entity. According to the superstring idea, all particles previously thought off as little points are in fact not points at all but basically little oscillating bits of "string" which move through space. The different levels of "vibration" of these strings correspond to the different particles.

Superstrings vibrate in 10 dimensions. But we don't notice these extra dimensions because they are curled up into a space that's infinitesimally small. Alas, it was discovered that there were at least five different string theories and millions of ways the extra dimensions could be curled up - an embarrassment of riches for those who hoped that string theory was the longed for theory of everything.

As others despaired, the American physicist Ed Witten led the way, beginning in the mid-1990s, in showing that the different string theories and a theory called "supergravity" were all just different approximations to a more fundamental theory: M-theory.

"M-theory is not a theory in the usual sense," admits Hawking. "It is a whole family of different theories, each of which is a good description of observations only in some range of physical situations. It is a bit like a map." Faithfully to map the entire earth, one has to use a collection of maps, each of which covers a limited region. The maps overlap each other, and where they do, they show the same landscape.

M-theory needs 11 space-time dimensions and contains not just vibrating strings but other objects that are impossible to visualize. The extra space dimensions can be curled up in a mind-blowing 10 to the 500th different ways, each leading to a universe with its own laws. To get an idea how many that is, Hawking and Mlodinow ask the reader to imagine a being capable of scanning each of those universes in just one millisecond and who started working on it at the Big Bang. Today that being would have only have scanned just 10 to the 20th of them.

This plethora of universes, the multiverse, explains what appears to be the mystery behind the remarkable coincidences that have fine-tuned natural laws to make our universe habitable for us. With so many universes, it's a lot less remarkable that there is at least one in which conditions are Goldilocks-like: just right to have given rise to us, since we exist it has to be this one. This is the anthrophic principle that effectively says that things are the way they are because they were the way they were. From here, Hawking goes on to argue "Because there is a law like gravity, the universe can and will create itself from nothing."

"'Think of an expanding universe as a surface of a bubble," writes Hawking. "Our picture of the spontaneous quantum creation of the universe is then a bit like the formation of bubbles of steam in boiling water. Many tiny bubbles appear, and then disappear again. These represent mini-universes that expand but collapse again while still of microscopic size. They represent possible alternative universes, but they are not of much interest since they do not last long enough to develop galaxies and stars, let alone intelligent life. A few of the little bubbles will grow long enough so that they will be safe from recollapse. They will continue to expand at an ever-increasing rate and will form the bubbles of steam we are able to see. These correspond to universes that start off expanding at an ever-increasing rate."

Spontaneous creation is the reason there is something rather than nothing; why the universe exists, why we exist. God is surplus to Hawking's requirements.

Why are the fundamental laws as they are? The ultimate theory must be consistent and must predict finite results for quantities that we can measure. There must be a law like gravity and, for a theory of gravity to predict finite quantities, the theory must have what is called "supersymmetry" between the forces of nature and the matter on which they act. "If the theory is confirmed by observation," says Hawking, "it will be the successful conclusion of a search going back more than 3000 years."

"Yet in the history of science," he admits, "we have discovered a sequence of better and better theories or models, from Plato to the classical theory of Newton to modern quantum theories. It is natural to ask: Will this sequence eventually reach an end point, an ultimate theory of the universe, that will include all forces and predict every observation we can make, or will we continue forever finding better theories, but never one that cannot be improved upon?"

Though Hawking is probably being rhetorical, Russell Stannard, a former professor of physics at the Open University, looks at the unanswered questions of modern physics in his book The End of Discovery (Oxford, £14.99). Stannard believes that eventually, but he doesn't know when, fundamental science will reach the limit of what it can explain. On that day, the Scientific Age, like the Stone Age and the Iron Age before it, will come to an end. He believes that not only technological limits, but maybe humanity will have reached the limits if its mental capacities to unravel the nature and workings of reality.

Stannard takes readers on a tour of some of the deepest questions facing science: questions to do with consciousness, free will, the nature of space, time, and matter. He covers much of the same territory as Hawking and Mlodinow, and points out that to understand the subatomic world, scientists depend of particle accelerators; but to understand the very smallest units of nature, it has been calculated that we would need an accelerator the size of a galaxy.

In A Brief History of Time, Hawking said that a scientific theory "may originally be put forward for aesthetic or metaphysical reasons, but the real test is whether it makes predictions that agree with observations". As they have waited for the next generation of particle accelerators and experiments, the research of physicists from superstrings to quantum cosmology has had a tendency to take on a metaphysical character in recent decades.

So maybe philosophy isn't as dead as Stephen Hawking thinks. For those having a difficult time wrapping their head around "spontaneous creation", he has this tip: "If you like, you can call the laws of science 'God'."

Wednesday, 1 September 2010

Why Beliefs Matter

A Matter of Faith

Why Beliefs Matter: Reflections on the nature of science by E. Brian Davies

New Scientist, 7 August 2010

Albert Einstein once asked, does the moon exist when no one is looking at it? Such questions had been the preserve of philosophers, but with the discovery of quantum mechanics in the 1920s they became legitimate queries for physicists, too.

Niels Bohr, one of the founders of quantum mechanics, did not believe that science grants us access to an objective reality and insisted that the task of physics was not to find out "how nature is" but only "what we can say about nature". Einstein, on the other hand, maintained an unshakeable belief in a reality that exists out there. Otherwise, he said, "I simply cannot see what it is that physics is meant to describe".

Einstein based his view of quantum mechanics on his belief in an independent reality - the moon does exist when no one is looking at it. In contrast, Bohr used the theory to construct and underpin his belief that the atomic realm has no independent reality. The two agreed on the equations but disagreed on what they meant.

"Scientists, like everyone else, have beliefs," writes distinguished mathematician E. Brian Davies in Why Beliefs Matter. He is not only referring to religious beliefs but to philosophical ones, too. While religious beliefs can be easy to leave at the laboratory door, philosophical beliefs are much harder to sideline.

Some mathematicians, for instance, subscribe to a Platonic view in which theorems are true statements about timeless entities that exist independent of human minds. Others believe that mathematics is a human enterprise invented to describe the regularities seen in nature. The very idea that nature has such regularities which render it comprehensible is itself a belief, as is the idea that the world we perceive is not some sort of delusion or practical joke.

The title of Davies's book, significantly, is a statement, not a question. For him, beliefs do matter. Davies offers a series of snapshots of how various philosophical views inform science, rather than a systematic inquiry into the nature of belief. Along the way he discusses the scientific revolution, the mind-body problem, machine intelligence, string theory and the multiverse. The result is a wide-ranging, thought-provoking meditation rather than a populist read. Beliefs, it seems, are a serious business, and they come in all shapes and sizes.

"At the highest level, beliefs become world views, fundamental beliefs that we use to evaluate other beliefs about the world," says Davies. World views can be evaluated, compared and changed, but you cannot avoid having one. Davies is a self-proclaimed pluralist. That is, he believes that humans have a limited mental capacity and will always need a multiplicity of ways of looking at the world in order to understand it. There may be two or more equally valid and complementary descriptions of the same phenomenon, he says - not unlike the concept of wave-particle duality in quantum mechanics. That does not mean that all world views are equally good - some simply don't hold up under the scrutiny of experiment.

The scientific revolution that began in the 16th century was a triumph of rationality and experiment over the superstition and speculation of the Middle Ages. Even so, nearly 40 per cent of Americans believe that God created humans some time within the last 10,000 years.

World views are not founded on logic, so the most that one can demand is that they should be consistent with what science has discovered. Yet, as the writer C. S. Lewis noted, some arguments are impossible to refute. "A belief in invisible cats cannot be logically disproved," he said, although it does "tell us a good deal about those who hold it".