The Hawking Paradox

His popular science book A Brief History of Time was a publishing sensation, staying at the top of the best-seller lists longer than any other book in recent history. But behind the public face lies an argument that has been raging for almost 30 years. Hawking shot to fame in the world of physics when he provided a mathematical proof for the "Big Bang" theory.

This theory showed that the entire Universe exploded from a singularity - an infinitely small point with infinite density and infinite gravity. Hawking was able to come to his proof using mathematical techniques that had been developed by Roger Penrose. However, Penrose's techniques were developed to deal not with the beginning of the Universe but with black holes. Science had long predicted that if a sufficiently large star collapsed at the end of its life, all the matter left in the star would be crushed into an infinitely small point with infinite gravity and infinite density - a singularity.




Hawking realised that the Universe was, in effect, a black hole in reverse; instead of matter being crushed into a singularity, the Universe began when a singularity expanded to form everything we see around us today - from stars to planets to people. Hawking realised that to come to a complete understanding of the Universe, he would have unravel the mysteries of the black hole.

Leaking Holes
Hawking and his fellow physicist embarked on an extraordinary intellectual expedition - to tame the black hole. The period from the early 70s to the early 80s became known as the "Golden Age" of black hole research. Slowly physicists were coming to understand its nature. But Hawking realised that there was something missing from the picture that was emerging. All work on black holes to that point used the physics of the large-scale Universe. The physics of gravity - first developed by Newton and then refined by Einstein's general theory of relativity.

Hawking realised that to come to a full understanding of black holes, physicists would also have to use the physics of the small-scale Universe; the physics that had been developed to explain the movements of atoms and sub-atomic particles known as quantum mechanics. The only problem was that no one had ever combined these two areas of physics before. This didn't deter Hawking. He set about developing a new way to force the physics of quantum mechanics to co-exist with Einstein's relativity within the intense gravity of a black hole.




After months of work, Hawking came up with a remarkable result. His equations were showing him that something was coming out of the black hole. This was supposed to be impossible - the one thing that everyone thought they knew about black holes was that things went in but nothing, not even light itself, could escape. The more Hawking checked, the more he was convinced he was right. He could see radiation coming out of the black hole. And it led him to the realisation that this radiation (later called Hawking radiation) would cause the black hole to evaporate and eventually disappear.

Shocking Revelation
Although Hawking's theories about black hole evaporation were revolutionary, they soon came to be widely accepted. But Hawking felt that this work had far more fundamental consequences. In 1976 he published a paper in Physical Review D called, "The breakdown of predictability in gravitational collapse". In this paper, Hawking argued that it wasn't just the black hole that disappeared. He said that all the information about everything that had ever been inside the black hole disappeared, too.

In everyday life, we're used to losing information - but according to physics this isn't supposed to happen; according to physics, information is never really lost, it just gets harder to find. The reason physicists cling on to the idea that information can't be lost is that it's their link with either the past or the future. If information is lost then science can never know the past or predict the future. There are limits to what science can know.




For many years, no one took much notice of Hawking's ideas until a fateful meeting in San Francisco. Hawking presented his ideas to some of the world's leading physicists, and in the audience were two particle physicists, Gerard t'Hooft and Leonard Susskind. They were shocked. They both grasped that Hawking's "breakdown of predictability" applied not only to black holes but to all processes in physics.

The Long Search
According to Susskind, if Hawking's ideas were correct then it would infect all physics; there would no longer be any direct link between cause and effect. Physics would become impotent. Since that meeting the "information paradox" has come to be seen as one of the most fundamental and most difficult problems in physics.

Arguments effectively boiled down into two camps. On the one side, Susskind and those who believed that Hawking was wrong and that information could not be lost - and on the other, Hawking and those who believed that physics would have to be re-written to take into account the uncertainty about information that Hawking had uncovered.

For 20 years, arguments raged. No side was willing to admit defeat... until a paper emerged written by a brilliant young Argentinean mathematician known as Juan Maldacena. This paper claimed to be a rigorous mathematical explanation of what happened to information in black holes - and it showed that information was not lost. Hawking, it seemed, was on the losing side. But Hawking was not convinced. Hawking set to work with a young research student, Christophe Galfard, to try to pick apart the Maldacena paper. They thought they could use the same mathematical techniques employed by Maldacena to prove that information was in fact lost. But after two years' work, they still could not prove their thesis.




Then disaster struck, Stephen Hawking was taken ill with pneumonia and rushed to hospital; doctors feared for his life. Hawking was kept in hospital for over three months. But whilst others fussed over his health, Hawking was thinking. Finally, on what many feared might be his death bed, he thought he'd come across what had eluded him for the past 30 years - a solution to the information paradox.

Bold Claims
Once again, Hawking defied doctors' dire predictions and was soon at work, working on a new proof for the information paradox. Then in July last year, at one of the most prestigious conferences in physics, Hawking made a dramatic announcement. He claimed to have solved the information paradox. But to the surprise of many in the audience, he was not at the conference to defend his long-held belief that information was lost in black holes. Instead, he was there to say he could now prove the opposite.

Hawking presented the outline of a proof that he hoped would at last solve the problem that he had posed almost 30 years earlier. However, despite the bold claims, some physicists remain unconvinced. Over a year has passed since the conference and Hawking has still not presented a fully worked mathematical proof to back up his ideas. But Hawking is a stubborn man. If he is going to change his mind on a belief he held for almost 30 years then it will be with his own proof, in his own time.




In spite of failing health and increasing problems communicating with his colleagues, Hawking is still working on the proof. If he succeeds in completing a proof that convinces his colleagues, he will not only have solved one of the most difficult problems in physics but he will have produced ground-breaking work at the very end of his career. That would be a feat that even his hero Einstein could not accomplish.

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We - Suzanna Arundhati Roy

Suzanna Arundhati Roy is an Indian writer and activist who won the Booker Prize in 1997 for her novel, The God of Small Things, and in 2002, the Lannan Cultural Freedom Prize.




Early in her career, Roy worked for television and movies. She wrote the screenplays for In Which Annie Gives It Those Ones (1989), a movie based on her experiences as a student of architecture, directed by her current husband, and Electric Moon (1992); in both she also appeared as a performer. Roy attracted attention when she criticised Shekhar Kapur's film Bandit Queen, based on the life of Phoolan Devi, charging Kapur with exploiting Devi and misrepresenting both her life and its meaning.




We is a fast-paced 64 minute documentary that covers the world politics of power, war, corporations, deception and exploitation. It visualizes the words of Arundhati Roy, specifically her famous Come September speech, where she spoke on such things as the war on terror, corporate globalization, justice and the growing civil unrest. It's witty, moving, alarming and quite a lesson in modern history.

We is almost in the style of a continuous music video. The music used sets the pace and serves as wonderful background for the words of Ms. Roy and images of humanity in the world we live all in today.

Einstein's Equation of Life and Death

In the summer of 1939 Albert Einstein was on holiday in a small resort town on the tip of Long Island. His peaceful summer, however, was about to be shattered by a visit from an old friend and colleague from his years in Berlin. The visitor was the physicist Leo Szilard. He had come to tell Einstein that he feared the Nazis could soon be in possession of a terrible new weapon and that something had to be done.

Szilard believed that recent scientific breakthroughs meant it was now possible to convert mass into energy. And that this could be used to make a bomb. If this were to happen, it would be a terrible realisation of the law of nature Einstein had discovered some 34 years earlier.

September 1905 was Einstein's 'miracle year'. While working as a patents clerk in the Swiss capital Berne Einstein submitted a three-page supplement to his special theory of relativity, published earlier that year. In those pages he derived the most famous equation of all time; e=mc², energy is equal to mass multiplied by the speed of light squared.

The equation showed that mass and energy were related and that one could, in theory, be transformed into the other. But because the speed of light squared is such a huge number, it meant that even a small amount of mass could potentially be converted into a huge amount of energy. Ever since the discovery of radioactivity in the late 19th century, scientists had realised that the atomic nucleus could contain a large amount of energy. Einstein's revolutionary equation showed them, for the first time, just how much there was.

However, at the time Einstein doubted whether that energy could ever be released. By 1935 he was convinced it would never be practical. At the Winter Session of the American Association for the Advancement of Science in Pittsburgh, he is quoted as telling journalists: "The likelihood of transforming matter into energy is something akin to shooting birds in the dark in a country where there are only a few birds."

Einstein was so sceptical because attempts to break open the atomic nucleus always required more far energy be put in than was ever released. Nuclear physicists like Ernest Rutherford were exploring the structure of the atom by bombarding atomic nuclei with alpha particles. Even when machines were built to accelerate the alpha particles to ever higher speeds they had only limited success in breaking apart the nucleus. In 1933 Rutherford dismissed talk of atomic power as 'moonshine'.

One morning in September 1933 Szilard read Rutherford's comments in The Times. Leaving his hotel and crossing the street, he had a brainwave. Alpha particles and the other particles that physicists had been using to bombard the nucleus were simply the wrong tool for the job, because he realised that they, like the nucleus, had a positive charge.

Since like charges repel, Szilard thought, no matter how hard you fire them in, the majority would simply be deflected away. That morning he was one of the first to realise that the recently discovered neutron might be what was needed. The neutron, a subatomic particle like a proton but with no electric charge was discovered in 1932. With no charge, Szilard believed the neutron would simply slip into the heart of the atom undeflected.

But he didn't stop there. Szilard thought that if an atom could be found that is split open by neutrons, not only would it release some of its huge store of energy, it might also release further neutrons, which could then go on and split further atoms, setting up a chain reaction leading to a truly vast release of energy. Szilard immediately saw the possible military applications and sought to patent the idea and have it made an official secret. But in 1933, the chain reaction only existed in Szilard's head. No one had yet found an atom that could be split by neutrons.

These developments were happening against a background of extraordinary political turmoil in Europe. Hitler had come to power in Germany in January 1933. In 1938, less than a year before the outbreak of World War II, just such an atom was found, uranium.

Working at the Kaiser Wilhelm Institute in Berlin, the nuclear chemists Otto Hahn and Fritz Strassman found that when bombarded with neutrons, uranium split into two nuclei of roughly half the size. Not only that, but further calculations showed that a large amount of energy was also released - enough from a single nucleus to move a grain of sand. The first stage of Szilard's chain reaction had been achieved.

When he heard the news Szilard, now in New York and working at Columbia University with Enrico Fermi, set about showing whether, as well as energy, further 'secondary' neutrons were released. By July 1939, when he first knocked on Einstein's door, he knew that they were and so the chain reaction was possible. Also, he and Fermi had settled on a design for the first nuclear reactor.

During the course of their conversations in the summer of 1939, Szilard explained these new developments to Einstein and his fear that the Nazis might use them to create a nuclear bomb. Together they drafted a letter, signed by Einstein, to the American President, Franklin Roosevelt. The letter was delivered to the President on the 11 October 1939 and after reading it the President provided funding for research that would pave the way for the Manhattan Project and lead, ultimately to the construction of the first atomic bomb. After signing the letter, Einstein played no further part in the development of the bomb.

With the first atomic explosion over Hiroshima, the power of e=mc² had been graphically demonstrated to the world. Just 0.6 grams of mass, converted into energy, had been enough to destroy an entire city.

Einstein was horrified when he heard that the bomb had been dropped. When they, wrote to the President, Szilard and Einstein advocated the development of an American bomb purely as a deterrent against the threat of a Nazi weapon. They had not conceived of its use as an offensive weapon, especially after the defeat of Nazi Germany.

Einstein always saw e=mc² as a purely theoretical insight and refuted any responsibility for the bomb but he did feel some responsibility for the letter he'd written to Roosevelt. A letter he would come to describe as "the one mistake" of his life. Einstein saw nuclear weapons and the nuclear arms race as a threat to the future of civilisation. In his final years he devoted much of his time and energy to issues dealing with the world's future - advocating pacifism and campaigning for the control of nuclear weapons, not by individual nations, but by a world government. The last document he signed, just a week before he died, was a manifesto drawn up by Bertrand Russell, renouncing war and nuclear weapons. As Russell said: ""Einstein was not only a great scientist he was a great man. He stood for peace in a world drifting towards war..."

But while the bomb proved e=mc² to be the ultimate equation of destruction, only after his death has the role of Einstein's equation in the creation of the universe become clear. Just as mass can be turned into energy in a bomb, the pure energy generated in the Big Bang condensed into the matter that makes up our world. Almost a hundred years ago, with just six short pen stokes Einstein unlocked one of the most powerful truths about the universe. A truth that would change our world, both for good and ill.

The Man Who Walked Across the World

This is a series of three documentary travelogues but they are nothing like Lonely Planet! Rather, in this stunning historical journey, Tim Mackintosh-Smith follows in the footsteps of 14th Century Moroccan scholar Ibn Battutah, who covered 75,000 miles, 40 countries and three continents in a 30-year odyssey.




Part One
Beginning in north Africa, Tim visits Battutah's birthplace of Tangier in Morocco, and stumbles on a performance of medieval trance music.




In Egypt, he goes to a remote village where Battutah had an astonishing prophetic dream and visits the world's oldest university in Cairo.

Part Two
In Turkey, Tim watches an illegal whirling dervish ceremony, and in the Taurus mountains he meets the last of the Turkoman nomads.




He chats to Tatars in Crimea, while in Delhi he watches a Muslim magician performing the Indian rope trick.

Part Three
In this final espisode, Tim explores the place of Islam in Hindu-dominated India and communist China, and tells the story of the Islamic trade empire of the 14th century.




In China, he meets a clan who trace their ancestry back to Arabs, and witnesses an illegal Arabic lesson.

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Was Darwin Right?

Was Darwin Wrong? Well, I don't want to spoil it for you but...of course he was NOT! This online documentary tests Darwin's main ideas and looks at the ideas of evolution's main critics.




From the air to the depths of the oceans our planet Earth is teeming with life. To some, it's a miracle but can science explain how this diversity of animals and plants evolved and how all this came into existence?




Critics have attacked the theory of evolution for 150 years. They claim it is full of holes, and the gaps reveal the hand of an Intelligent Designer. Who's right?

Watch Was Darwin Wrong? in How to Videos | View More Free Videos Online at Veoh.com

We investigate the most explosive science of them all and ask, was Darwin wrong? When Darwin published the Origin of Species in 1859 his ideas rocked the world. His claim, that nature and nature alone could create all life, removed the need for an Intelligent Designer. Overnight religious explanations of existence became redundant. But 150 years later, Darwin's theory is still under attack. We look at the claims Darwin made and see how they measure up in the light of modern science.

Click here for a super cool interactive documentary on human evolution.

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The Human Footprint

Have you ever wondered what it would look like if all the clothes, washing machines and toilet paper you ever used were piled up outside your front door? Or if you were to lay out all the bread you will ever eat or cups of tea you will drink? This beautiful, landmark film uses art and science to explore the impact each and every human has on the planet in an average lifetime, demonstrating the massive scale of everything consumed and produced in one lifetime.

Featuring a series of arresting art installations and mind-boggling statistics, Human Footprint follows the average life journey from the cradle to the grave, showing just how much, how often and for how long we will each consume. How much food and drink we will devour, how many tears we will cry, how much hair we will shed and how much waste matter we will process through our bodies – all within the 2 billion 475 million, 5,076 seconds that each of us will, on average, spend on earth.

Human Footprint also features several experts, who explain the science behind the installations and explore the profound effect our individual footprints will have on the planet. From our babyhood – when we get through a massive 3,796 nappies and produce 254 litres of urine – through to our old age and death – by which time we will have had sex 4,239 times, eaten 10,866 carrots, taken 7,163 baths and done an average of 15 farts a day – this online documentary tells the story of an average life, the story of our human footprint.

Click here for the fantastic interactive official site.

Buy the DVD now...