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Showing posts with label physics. Show all posts
Showing posts with label physics. Show all posts

Sunday 15 April 2018

'There is no such thing as past or future': physicist Carlo Rovelli on changing how we think about time

Charlotte Higgins on Carlo Rovelli's book on the elastic concept of time. Source The Guardian


What do we know about time? Language tells us that it “passes”, it moves like a great river, inexorably dragging us with it, and, in the end, washes us up on its shore while it continues, unstoppable. Time flows. It moves ever forwards. Or does it? Poets also tell us that time stumbles or creeps or slows or even, at times, seems to stop. They tell us that the past might be inescapable, immanent in objects or people or landscapes. When Juliet is waiting for Romeo, time passes sluggishly: she longs for Phaethon to take the reins of the Sun’s chariot, since he would whip up the horses and “bring in cloudy night immediately”. When we wake from a vivid dream we are dimly aware that the sense of time we have just experienced is illusory.

Carlo Rovelli is an Italian theoretical physicist who wants to make the uninitiated grasp the excitement of his field. His book Seven Brief Lessons on Physics, with its concise, sparkling essays on subjects such as black holes and quanta, has sold 1.3m copies worldwide. Now comes The Order of Time, a dizzying, poetic work in which I found myself abandoning everything I thought I knew about time – certainly the idea that it “flows”, and even that it exists at all, in any profound sense.

We meet outside the church of San Petronio in Bologna, where Rovelli studied. (“I like to say that, just like Copernicus, I was an undergraduate at Bologna and a graduate at Padua,” he jokes.) A cheery, compact fellow in his early 60s, Rovelli is in nostalgic mood. He lives in Marseille, where, since 2010, he has run the quantum gravity group at the Centre de physique théorique. Before that, he was in the US, at the University of Pittsburgh, for a decade.


Carlo Rovelli in Bologna. Photograph: Roberto Serra / Iguana Press / G/Iguana Press / Getty Images

He rarely visits Bologna, and he has been catching up with old friends. We wander towards the university area. Piazza Verdi is flocked with a lively crowd of students. There are flags and graffiti and banners, too – anti-fascist slogans, something in support of the Kurds, a sign enjoining passers-by not to forget Giulio Regeni, the Cambridge PhD student killed in Egypt in 2016.

“In my day it was barricades and police,” he says. He was a passionate student activist, back then. What did he and his pals want? “Small things! We wanted a world without boundaries, without state, without war, without religion, without family, without school, without private property.”

He was, he says now, too radical, and it was hard, trying to share possessions, trying to live without jealousy. And then there was the LSD. He took it a few times. And it turned out to be the seed of his interest in physics generally, and in the question of time specifically. “It was an extraordinarily strong experience that touched me also intellectually,” he remembers. “Among the strange phenomena was the sense of time stopping. Things were happening in my mind but the clock was not going ahead; the flow of time was not passing any more. It was a total subversion of the structure of reality. He had hallucinations of misshapen objects, of bright and dazzling colours – but also recalls thinking during the experience, actually asking himself what was going on.

“And I thought: ‘Well, it’s a chemical that is changing things in my brain. But how do I know that the usual perception is right, and this is wrong? If these two ways of perceiving are so different, what does it mean that one is the correct one?’” The way he talks about LSD is, in fact, quite similar to his description of reading Einstein as a student, on a sun-baked Calabrian beach, and looking up from his book imagining the world not as it appeared to him every day, but as the wild and undulating spacetime that the great physicist described. Reality, to quote the title of one of his books, is not what it seems.

He gave his conservative, Veronese parents a bit of a fright, he says. His father, now in his 90s, was surprised when young Carlo’s lecturers said he was actually doing all right, despite the long hair and radical politics and the occasional brush with the police. It was after the optimistic sense of student revolution in Italy came to an abrupt end with the kidnapping and murder of the former prime minister, Aldo Moro, in 1978 that Rovelli began to take physics seriously. But his route to his big academic career was circuitous and unconventional. “Nowadays everyone is worried because there is no work. When I was young, the problem was how to avoid work. I did not want to become part of the ‘productive system’,” he says.

Academia, then, seemed like a way of avoiding the world of a conventional job, and for some years he followed his curiosity without a sense of careerist ambition. He went to Trento in northern Italy to join a research group he was interested in, sleeping in his car for a few months (“I’d get a shower in the department to be decent”). He went to London, because he was interested in the work of Chris Isham, and then to the US, to be near physicists such as Abhay Ashtekar and Lee Smolin. “My first paper was horrendously late compared to what a young person would have to do now. And this was a privilege – I knew more things, there was more time.”


Albert Einstein worked at the Swiss patent office for seven years: ‘That worldly cloister where I hatched my most beautiful ideas.’ Photograph: Keystone/Getty Images

The popular books, too, have come relatively late, after his academic study of quantum gravity, published in 2004. If Seven Brief Lessons was a lucid primer, The Order of Timetakes things further; it deals with “what I really do in science, what I really think in depth, what is important for me”.

Rovelli’s work as a physicist, in crude terms, occupies the large space left by Einstein on the one hand, and the development of quantum theory on the other. If the theory of general relativity describes a world of curved spacetime where everything is continuous, quantum theory describes a world in which discrete quantities of energy interact. In Rovelli’s words, “quantum mechanics cannot deal with the curvature of spacetime, and general relativity cannot account for quanta”.

Both theories are successful; but their apparent incompatibility is an open problem, and one of the current tasks of theoretical physics is to attempt to construct a conceptual framework in which they both work. Rovelli’s field of loop theory, or loop quantum gravity, offers a possible answer to the problem, in which spacetime itself is understood to be granular, a fine structure woven from loops.

String theory offers another, different route towards solving the problem. When I ask him what he thinks about the possibility that his loop quantum gravity work may be wrong, he gently explains that being wrong isn’t the point; being part of the conversation is the point. And anyway, “If you ask who had the longest and most striking list of results it’s Einstein without any doubt. But if you ask who is the scientist who made most mistakes, it’s still Einstein.”

How does time fit in to his work? Time, Einstein long ago showed, is relative – time passes more slowly for an object moving faster than another object, for example. In this relative world, an absolute “now” is more or less meaningless. Time, then, is not some separate quality that impassively flows around us. Time is, in Rovelli’s words, “part of a complicated geometry woven together with the geometry of space”.

For Rovelli, there is more: according to his theorising, time itself disappears at the most fundamental level. His theories ask us to accept the notion that time is merely a function of our “blurred” human perception. We see the world only through a glass, darkly; we are watching Plato’s shadow-play in the cave. According to Rovelli, our undeniable experience of time is inextricably linked to the way heat behaves. In The Order of Time, he asks why can we know only the past, and not the future? The key, he suggests, is the one-directional flow of heat from warmer objects to colder ones. An ice cube dropped into a hot cup of coffee cools the coffee. But the process is not reversible: it is a one-way street, as demonstrated by the second law of thermodynamics.

String theory offers an alternative to Rovelli’s work in loop quantum gravity.

Time is also, as we experience it, a one-way street. He explains it in relation to the concept of entropy – the measure of the disordering of things. Entropy was lower in the past. Entropy is higher in the future – there is more disorder, there are more possibilities. The pack of cards of the future is shuffled and uncertain, unlike the ordered and neatly arranged pack of cards of the past. But entropy, heat, past and future are qualities that belong not to the fundamental grammar of the world but to our superficial observation of it. “If I observe the microscopic state of things,” writes Rovelli, “then the difference between past and future vanishes … in the elementary grammar of things, there is no distinction between ‘cause’ and ‘effect’.”

To understand this properly, I can suggest only that you read Rovelli’s books, and pass swiftly over this approximation by someone who gave up school physics lessons joyfully at the first possible opportunity. However, it turns out that I am precisely Rovelli’s perfect reader, or one of them, and he looks quite delighted when I check my newly acquired understanding of the concept of entropy with him. (“You passed the exam,” he says.)

“I try to write at several levels,” he explains. “I think about the person who not only doesn’t know anything about physics but is also not interested. So I think I am talking to my grandmother, who was a housekeeper. I also think some young students of physics are reading it, and I also think some of my colleagues are reading it. So I try to talk at different levels, but I keep the person who knows nothing in my mind.”

His biggest fans are the blank slates, like me, and his colleagues at universities – he gets most criticism from people in the middle, “those who know a bit of physics”. He is also pretty down on school physics. (“Calculating the speed at which a ball drops – who cares? In another life, I’d like to write a school physics book,” he says.) And he thinks the division of the world into the “two cultures” of natural sciences and human sciences is “stupid. It’s like taking England and dividing the kids into groups, and you tell one group about music, and one group about literature, and the one who gets music is not allowed to read novels and the one who does literature is not allowed to listen to music.”


In the elementary grammar of things, there is no distinction between ‘cause’ and ‘effect’

The joy of his writing is its broad cultural compass. Historicism gives an initial hand-hold on the material. (He teaches a course on history of science, where he likes to bring science and humanities students together.) And then there’s the fact that alongside Einstein, Ludwig Boltzmann and Roger Penrose appear figures such as Proust, Dante, Beethoven, and, especially, Horace – each chapter begins with an epigraph from the Roman poet – as if to ground us in human sentiment and emotion before departing for the vertiginous world of black holes and spinfoam and clouds of probabilities.

“He has a side that is intimate, lyrical and extremely intense; and he is the great singer of the passing of time,” Rovelli says. “There’s a feeling of nostalgia – it’s not anguish, it’s not sorrow – it’s a feeling of ‘Let’s live life intensely’. A good friend of mine, Ernesto, who died quite young, gave me a little book of Horace, and I have carried it around with me all my life.”

Rovelli’s view is that there is no contradiction between a vision of the universe that makes human life seem small and irrelevant, and our everyday sorrows and joys. Or indeed between “cold science” and our inner, spiritual lives. “We are part of nature, and so joy and sorrow are aspects of nature itself – nature is much richer than just sets of atoms,” he tells me. There’s a moment in Seven Lessons when he compares physics and poetry: both try to describe the unseen. It might be added that physics, when departing from its native language of mathematical equations, relies strongly on metaphor and analogy. Rovelli has a gift for memorable comparisons. He tells us, for example, when explaining that the smooth “flow” of time is an illusion, that “The events of the world do not form an orderly queue like the English, they crowd around chaotically like the Italians.” The concept of time, he says, “has lost layers one after another, piece by piece”. We are left with “an empty windswept landscape almost devoid of all trace of temporality … a world stripped to its essence, glittering with an arid and troubling beauty”.

More than anything else I’ve ever read, Rovelli reminds me of Lucretius, the first-century BCE Roman author of the epic-length poem, On the Nature of Things. Perhaps not so odd, since Rovelli is a fan. Lucretius correctly hypothesised the existence of atoms, a theory that would remain unproven until Einstein demonstrated it in 1905, and even as late as the 1890s was being written off as absurd.

What Rovelli shares with Lucretius is not only a brilliance of language, but also a sense of humankind’s place in nature – at once a part of the fabric of the universe, and in a particular position to marvel at its great beauty. It’s a rationalist view: one that holds that by better understanding the universe, by discarding false beliefs and superstition, one might be able to enjoy a kind of serenity. Though Rovelli the man also acknowledges that the stuff of humanity is love, and fear, and desire, and passion: all made meaningful by our brief lives; our tiny span of allotted time.

Saturday 7 May 2016

Is it science or theology?

Pervez Hoodbhoy in The Dawn

When Pakistani students open a physics or biology textbook, it is sometimes unclear whether they are actually learning science or, instead, theology. The reason: every science textbook, published by a government-run textbook board in Pakistan, by law must contain in its first chapter how Allah made our world, as well as how Muslims and Pakistanis have created science.

I have no problem with either. But the first properly belongs to Islamic Studies, the second to Islamic or Pakistani history. Neither legitimately belongs to a textbook on a modern-day scientific subject. That’s because religion and science operate very differently and have widely different assumptions. Religion is based on belief and requires the existence of a hereafter, whereas science worries only about the here and now.

Demanding that science and faith be tied together has resulted in national bewilderment and mass intellectual enfeeblement. Millions of Pakistanis have studied science subjects in school and then gone on to study technical, science-based subjects in college and university. And yet most — including science teachers — would flunk if given even the simplest science quiz.

How did this come about? Let’s take a quick browse through a current 10th grade physics book. The introductory section has the customary holy verses. These are followed by a comical overview of the history of physics. Newton and Einstein — the two greatest names — are unmentioned. Instead there’s Ptolemy the Greek, Al-Kindi, Al-Beruni, Ibn-e-Haytham, A.Q. Khan, and — amusingly — the heretical Abdus Salam.

The end-of-chapter exercises test the mettle of students with such questions as: Mark true/false; A) The first revelation sent to the Holy Prophet (PBUH) was about the creation of Heaven? B) The pin-hole camera was invented by Ibn-e-Haytham? C) Al-Beruni declared that Sind was an underwater valley that gradually filled with sand? D) Islam teaches that only men must acquire knowledge?

Dear Reader: You may well gasp in disbelief, or just hold your head in despair. How could Pakistan’s collective intelligence and the quality of what we teach our children have sunk so low? To see more such questions, or to check my translation from Urdu into English, please visit the websitehttp://eacpe.org/ where relevant pages from the above text (as well as from those discussed below) have been scanned and posted.

Take another physics book — this one (English) is for sixth-grade students. It makes abundantly clear its discomfort with the modern understanding of our universe’s beginning. The theory of the Big Bang is attributed to “a priest, George Lamaitre [sic] of Belgium”. The authors cunningly mention his faith hoping to discredit his science. Continuing, they declare that “although the Big Bang Theory is widely accepted, it probably will never be proved”.

While Georges Lemaître was indeed a Catholic priest, he was so much more. A professor of physics, he worked out the expanding universe solution to Einstein’s equations. Lemaître insisted on separating science from religion; he had publicly chided Pope Pius XII when the pontiff grandly declared that Lemaître’s results provided a scientific validation to Catholicism.

Local biology books are even more schizophrenic and confusing than the physics ones. A 10th-grade book starts off its section on ‘Life and its Origins’ unctuously quoting one religious verse after another. None of these verses hint towards evolution, and many Muslims believe that evolution is counter-religious. Then, suddenly, a full page annotated chart hits you in the face. Stolen from some modern biology book written in some other part of the world, it depicts various living organisms evolving into apes and then into modern humans. Ouch!

Such incoherent babble confuses the nature of science — its history, purpose, method, and fundamental content. If the authors are confused, just imagine the impact on students who must learn this stuff. What weird ideas must inhabit their minds!

Compounding scientific ignorance is prejudice. Most students have been persuaded into believing that Muslims alone invented science. And that the heroes of Muslim science such as Ibn-e-Haytham, Al-Khwarizmi, Omar Khayyam, Ibn-e-Sina, etc owed their scientific discoveries to their strong religious beliefs. This is wrong.

Science is the cumulative effort of humankind with its earliest recorded origins in Babylon and Egypt about 6,000 years ago, thereafter moving to China and India, and then Greece. It was a millennium later that science reached the lands of Islam, where it flourished for 400 years before moving on to Europe. Omar Khayyam, a Muslim, was doubtless a brilliant mathematician. But so was Aryabhatta, a Hindu. What does their faith have to do with their science? Natural geniuses have existed everywhere and at all times.

Today’s massive infusion of religion into the teaching of science dates to the Ziaul Haq days. It was not just school textbooks that were hijacked. In the 1980s, as an applicant to a university teaching position in whichever department, the university’s selection committee would first check your faith.

In those days a favourite question at Quaid-e-Azam University (as probably elsewhere) was to have a candidate recite Dua-i-Qunoot, a rather difficult prayer. Another was to name each of the Holy Prophet’s wives, or be quizzed about the ideology of Pakistan. Deftly posed questions could expose the particularities of the candidate’s sect, personal degree of adherence, and whether he had been infected by liberal ideas.

Most applicants meekly submitted to the grilling. Of these many rose to become today’s chairmen, deans, and vice-chancellors. The bolder ones refused, saying that the questions asked were irrelevant. With strong degrees earned from good overseas universities, they did not have to submit to their bullying inquisitors. Decades later, they are part of a widely dispersed diaspora. Though lost to Pakistan, they have done very well for themselves.

Science has no need for Pakistan; in the rest of the world it roars ahead. But Pakistan needs science because it is the basis of a modern economy and it enables people to gain decent livelihoods. To get there, matters of faith will have to be cleanly separated from matters of science. This is how peoples around the world have managed to keep their beliefs intact and yet prosper. Pakistan can too, but only if it wants.

Tuesday 27 August 2013

Is it time to rewrite the laws of physics?



'Time is an illusion. Lunchtime doubly so,” said Ford Prefect in Douglas Adams’s The Hitchhiker’s Guide to the Galaxy. For the past century, mainstream physics has agreed with him. To most of us, it seems obvious that the world is moving steadily forward through time, from a known past, through an active present, into a mysterious future. But, as Einstein said, “physicists believe the separation between past, present, and future is only an illusion, although a convincing one”.
“Mainstream physics basically eliminates time as a fundamental aspect of nature,” explains Prof Lee Smolin, a physicist at the Perimeter Institute for Theoretical Physics, in Ontario, Canada. “It does that in various ways, but the most common is the so-called 'block universe’ picture, which is derived from general relativity.”
Under this system, what is actually real is not our passage through time, but the whole of reality at once. “Imagine taking a movie of your life,” says Prof Smolin, “and laying out the frames on a table, and saying: that is your life. There is no now, there is no change.”
He thinks that it is high time – so to speak – this view was overturned. In his new book Time Reborn, he makes the case that time is a fundamental reality of the universe, and that without it, too many of the big questions of physics are left unanswerable.
The question of what time is, and whether it is real or illusory, is an ancient one. Even before Plato, Greek philosophers were debating whether, as Heraclitus said, you cannot step in the same river twice, that all is flux and change, or whether Parmenides was right and that change is an illusion, that the universe simply exists as an unchanging lump.
The first person to address the issue in depth, according to Dr Julian Barbour, author of The End of Time, was St Augustine. He was baffled by it, and said as much. “What then is time?” Augustine wrote. “If no one asks of me, I know; if I wish to explain to him who asks, I know not.” Still, he did make an attempt to explain it, coming to the surprisingly modern conclusion that there could not have been time before the world, because there would have been no change, and without change, time is meaningless.
Sir Isaac Newton, a thousand years later, disagreed. He held the common-sense view – instinctively shared by the rest of us – that time is absolute, marching on regardless of the doings of the stuff of the universe. It was Einstein who showed that it was no such thing. According to his theories of relativity, time and space are part of an interwoven fabric: the presence of matter changes both, stretching the fabric like a weight on a sheet.
His theories are counterintuitive – arguing that someone who is travelling ages slower than someone who is standing still, and that time goes faster the further we get from the surface of the Earth – but at least, in his universe, there is such a thing as time.
“Einstein, in a way, makes time something real – with the idea of space-time, he makes it as real as space,” says Dr Barbour. But there is a fundamental difference, which leads us to one of the great problems with our concept of time: “We get the impression that we are always moving through time, when we can perfectly happily sit still and have no impression that we are moving through space. That’s a very big mystery, because the laws of physics work exactly the same way whether you run them forwards or backwards.”
Clearly, that is not how we perceive the world. We see babies be born, grow old and die; water flowing downhill; and wood burning to ash. “If you drop an egg on the floor, it breaks, and there is no way you can put that egg back together again,” says Dr Barbour.
This is due to a property called entropy, or disorder. The second law of thermodynamics dictates that the universe will move from ordered, low-entropy states to disordered, high-entropy states: ice will melt and coffee will cool, until everything is the same temperature, and everything is mixed together in an undifferentiated mass. “According to the fundamental laws of physics as we know them, it shouldn’t make any difference which way you look at them. And yet it is clearly the case that entropy increases,” Dr Barbour says.
That leaves an awful lot of questions unanswered – which is where Prof Smolin’s ideas come in. “The second law dictates that any system in disequilibrium should come quickly to equilibrium,” he points out. “But our universe, even though it’s more than 13 billion years old, is very far from equilibrium.”
This is due to particular facts about the laws of physics – such as the strength of gravity, or the precise set of particles we observe – and the very specific way that the universe began. But Prof Smolin points out that we still do not know why those laws are as they are, or why the universe should have started in its particular way: “There seems to be no simple principle that picks out the standard model of particle physics from a vast number of equally likely possibilities.” Uncountable billions of other universes could have existed in which there would be no stars, no planets, and no us.
Prof Smolin’s point is that, for modern physics, in which time is treated as an illusion, this question is unanswerable. “The initial conditions and laws, in the block universe model, are just part of the universe. It would be like asking a computer to explain the program it’s running.” But if we treat the laws as things that could have been different had history gone differently, or that can change with time, “then time has to exist prior to those laws, and then it has to be real in a way that the block universe doesn’t allow”.
There is a risk with much of theoretical physics that it strays into a realm of philosophy, away from the science of experiment and reality. Prof Smolin insists that this is not the case: his idea of “real time” includes hypotheses that make testable predictions. One such experiment might be to use quantum computers, which, in theory, will be able to detect the evolution of physical laws. Dr Barbour (whose book tends to support the time-is-an-illusion school of thought), says that observations of astronomical phenomena called gamma-ray bursts might also show violations of Einstein’s laws at the universe’s smallest scale – although so far, he says, they have proved remarkably robust.
If Prof Smolin is right, he believes that it will have implications far beyond academic physics. “A lot of our thinking about many things, from the nature of being human to political and environmental problems, are poisoned by the belief that the future is already determined and that we can’t find truly novel solutions,” he says. “For example, in economics, the insistence that the laws are formalised in a timeless mathematical setting, like Newtonian physics, leads to some incorrect ideas, which helped contribute to the economic disaster of 2008.” A model of the world in which “the future is open, and the universe can discover novel structures, novel ideas, creates a very different idea of our possibilities” – and could lead to some very different thinking.
Whether he’s right or not, only time itself will tell. Certainly, physics has done away with the concept of time for so long that simply saying that it is real feels almost revolutionary.

Friday 26 July 2013

The DRS problem: it's not the humans stupid


Kartikeya Date 

The controversial Trott decision: what many observers don't get is that it wasn't actually the third umpire who made the final call  © PA Photos
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The DRS is a system in which umpiring decisions can be reviewed by players. Events on the field can also be reviewed by umpires in some circumstances before a decision is made. A widely held view about recent problems with the system is that while the DRS is fine, the way it is used by players, and on occasion by umpires, has caused difficulties.
I hold the view that the problem, if there is one, is with the system, not with the way it is used. The way the system is defined strictly determines the way it is used.
The DRS system I refer to is described in detail by the ICC in its Playing Handbook (pdf). It is worth clearing up a few misconceptions at the outset.
The TV umpire does not overturn a decision under the DRS. The TV umpire is explicitly prohibited from discussing whether or not a particular appeal should result in an out or a not out. Further, there is no standard in the DRS requiring "conclusive evidence to the contrary" to overturn a decision, as many commentators are fond of telling us.
The rules make only three points. First, the TV umpire must limit himself to the facts. Second, if some of the evidence requested by the umpire on the field does not permit a conclusion with "a high degree of confidence", the TV umpire should convey to the umpire on the field that a conclusive answer is not possible (the conclusion in this case is not the decision itself but about individual points of fact potentially influencing it). Finally, if some information is not available to the TV umpire, he is required to report this to the on-field umpire. He is also required to provide all other evidence requested by the on-field umpire. If we go by the ICC's DRS rules, at no point in the review process is the TV umpire required to provide a definitive conclusion by putting together all the evidence.
The Guardian reported that the ICC did admit to a protocol error in the way the umpires addressed Australia's review in Jonathan Trott's first-ball lbw dismissal in the second innings at Trent Bridge. The ICC has declined to say what the protocol error was, citing a long-standing policy of not revealing communication between umpires. A number of observers think that the absence of one Hot Spot camera angle should have automatically meant that the outcome of the review should have been inconclusive, allowing Dar's original not-out decision to stand. I think this is a misreading of the ICC's DRS rules.
Let's reconstruct the case of Trott. Umpire Erasmus in the TV umpire's box would not be asked "Is Trott LBW?", or even "Did Trott hit the ball with the bat?" Going by the ICC's rules, he would be asked a different series of questions. Does Hot Spot show a touch? No. Does the replay show a touch?Inconclusive. No clear evidence of a deviation. (Some people have argued that there was evidence of deviation on the replay. I disagree. As did Michael Atherton on live commentary.) Does the square-of-the-wicket Hot Spot show a touch? This angle is unavailable. Can you hear any relevant sound on the stump microphone? Inconclusive. Did the ball pitch in line? Yes. Did it hit the pads in line? Yes. Does the ball-track predict that it would have hit the stumps?Yes.
According to the rules, Erasmus would be prevented from providing probabilities or maybes. It would have to be yes, no, or can't say. After getting all these factual responses from Erasmus, Dar would have to make up his mind. Did what he heard from Erasmus merit reversal? As we know, he decided that it did. The protocol error could have been that Erasmus neglected to mention that one of the Hot Spot angles was unavailable. It could also have been that Dar weighed all the facts Erasmus provided to him incorrectly and reached the wrong conclusion, though it is difficult to construe this last possibility as a protocol error, since the protocol explicitly requires the on-field umpire to exercise judgement, which is what Dar did. "The on-field umpire must then make his decision based on those factual questions that were answered by the third umpire, any other factual information offered by the third umpire and his recollection and opinion of the original incident" (See 3.3[k] of Appendix 2 of the Standard Test Match Playing Conditions, ICC Playing Handbook 2012-13).
This is the central faultline in the understanding of the DRS. To some technophiles, it promises an end to interpretation; that, with the DRS, there is to be no more "in the opinion of the umpire". Technology will show everything clearly - make every decision self-evident.
Not so. Under the DRS, a judgement has to be made about whether or not evidence is conclusive. A judgement also has to be made about whether all the evidence (often conflicting, due to the limitations of the technologies involved), taken together, merits a reversal. There have been instances where outside edges have been ruled to have occurred, though there was no heat signature on the bat.
The ICC has consistently insisted that the idea is not to render umpires obsolete. It is right, but in a convoluted way. What the DRS does is allow umpires a limited, strictly defined second look at an event. But it does so on the players' terms. Umpires are currently not allowed to review a decision after it has been made on the field. The "umpire review" element of the DRS takes place before the decision is made on the field in the first instance. Simon Taufel, who has wide experience of both DRS and non-DRS international matches, has questioned whether this is reasonable.
So far, the DRS has been badly burnt in the ongoing Ashes, and has received criticism from some unexpected quarters. Add to this a recent report that a few boards other than India's also oppose it. I suspect that the DRS will not survive in its present form for long.
The ICC is experimenting with real-time replays, which it says will allow TV umpires to initiate reviews. The ICC has long claimed that this is currently not done because it will waste time. The ICC's statistics suggest that in an average DRS Test match, 49 umpiring decisions are made (a decision is said to be made when an appeal from the fielding side is answered). Let's say an average Test lasts 12 sessions. This suggests that on average about four appeals are made per session of Test cricket when the DRS is employed. These numbers don't suggest that allowing umpires to initiate reviews will result in too much extra wasted time, do they? It should be kept in mind, though, that the ICC assesses time wasted relative to the progress of the game, and not simply as a measure in seconds or minutes.
The most damaging consequence of the DRS is off the field. It has now become a point of debate among professional observers of cricket about whether dismissals are determined by the umpire. The idea that the umpire is an expert whose role it is to exercise judgement, and whose judgement is to be respected, is now only superficially true. Time and again, eminently reasonable lbw decisions are reversed for fractions, and as a result are considered clear mistakes. Cricket has lost the ability to appreciate the close decision, the marginal event. It has lost the essential sporting capacity to concede that an event on the field is so close that perhaps a decision in favour of the opposition is reasonable.

Wednesday 27 March 2013

Cricket, Physics and the Laws of Probability



In the recently concluded test match between New Zealand and England an event occurred which in this writer's opinion once again questions the predictability of an lbw decision as a method of dismissing a batsman and especially the DRS system which is being touted as a scientific fact. On the last ball of the 99th over in the England second innings the ball, to quote Andy Zaltzman in Cricinfo:

The ball ricocheted from Prior's flailing bat/arms/head, and plonked downwards, in accordance the traditions of gravity, onto the timbers. It did not brush the stumps. It did not snick the stumps. It did not gently fondle the stumps. It hit the stumps. The bails, perhaps patriotically mindful of their origins in early cricket in England all those years ago, defied all the conventional principles of science by not falling off.

If the stumps and bails had behaved as cricketing precedent and Isaac Newton would have expected them to behave, England would have been seven wickets down with 43 overs left.

If the ball having hit the stumps fails to dislodge the bails then doesn't it introduce even more uncertainty into a DRS based lbw decision which its supporters claim to be irrefutable evidence? This incident requires that in an lbw appeal the DRS should not only predict whether the ball, if not impeded by the batsman illegally, would have gone on to hit the stumps but also if it would dislodge the bails.

Supporters of the DRS rely on the infallibility of scientific laws to promote their support for technology. Then, like true scientists they should admit the weakness of their science whenever an anomaly appears. Assuming for a moment that these scientific laws are infallible then how do they explain the reprieve that Prior obtained? Also, shouldn't the DRS have been used to declare Prior out since the ball had actually hit the stumps?

Hence I would like to make a suggestion which may unite the supporters and opponents of the DRS. I suggest that the LBW as a method of dismissing a batsman should be struck off from the laws of cricket. Instead, a run penalty should be imposed on the batsman every time the ball comes in contact with an  'illegal' part of his/her body. The DRS could be used to adjudicate on this decision. The penalty could be  ten runs and increasing every time the batsman uses such illegitimate methods to stay at the crease.

I look forward to a debate.

Related article

Abolish the LBW - it has no place in the modern world

Wednesday 4 July 2012

Higgs Boson - The Indian connection


The gods of the particles

The Higgs bit we know. But the boson? Western science is overlooking India's contribution to the discovery
Higgs bosun Bose
Satyendra Nath Bose (‘bosun') realised in 1924 the method used to analyse work on the thermal behaviour of gases was inadequate'. Photo: National Geographic/Alamy
With tomorrow's announcement of the latest findings in the search for the Higgs boson, the elusive particle is on everyone's mind. This kind of fame is relatively rare, even for important scientific discoveries; but the Higgs boson has been called, or miscalled, the God particle, enabling it to pass into the realm of popular scientific lore, like the discovery of the smallpox vaccine, the structure of DNA, or the theory of relativity.

It would be difficult for most people to understand its significance, just as it would be to comprehend the notion of relativity, but such problems are overcome by locating science in personalities as well as cultural and national traditions. The first thing that you and I know about the Higgs boson is that it's named after Peter Higgs, a physicist at Edinburgh University who made the discovery – although the original insight, in one of those recurrent back stories of science, was Philip Anderson's.

Still, we have Higgs, and Edinburgh, and western civilisation to fall back on. The rest – "the Higgs boson is a hypothetical elementary particle predicted by the Standard Model of particle physics. It belongs to a class of particles known as bosons ..." – we needn't worry too much about. But maybe we should worry just enough to ask, "What is a boson?", since the word tends to come up as soon as Higgs does. Is it, an ignoramus such myself would ask, akin to an atom or a molecule? It is, in fact, along with the fermion (named after Enrico Fermi), one of the two fundamental classes of subatomic particles.

The word must surely have some European, perhaps German, genealogy? In fact, "boson" is derived from Satyendra Nath Bose, an Indian physicist from Kolkata who, in 1924, realised that the statistical method used to analyse most 19th-century work on the thermal behaviour of gases was inadequate. He first sent off a paper on the quantum statistics that he perfected in Dhaka to a British journal, which turned it down. He then sent it to Albert Einstein, who immediately grasped its immense importance, translated the paper, and published it in a German journal. (And so our invented German provenance turns out to be not wholly inappropriate.) Bose's innovation came to be known as the Bose-Einstein statistics, and became a basis of quantum mechanics. Einstein saw that it had profound implications for physics; that it had opened the way for this subatomic particle, which he named, after his Indian collaborator, "boson". Few physicists would disagree with the suggestion that the Bose-Einstein statistics have had much wider consequences for physics than the Higgs boson has had.

Still, science and the west are largely synonymous and coeval: they are two words that have the same far-reaching meaning. Just as Van Gogh and Toulouse-Lautrec's paintings consume and digest the Japanese prints they were responding to so that we don't need to be aware of Japanese prints when viewing the post-impressionists, western science is pristine, and bears no mark of what's outside itself.

The last Indian scientific discovery that is fairly universally acknowledged is the zero. As Carol Vorderman has pointed out, Indians are very strong at maths, and the only modern Indian who's remotely part of the popular western mythology of science isSrinivasa Ramanujan, equally well known for his Hindu idiosyncrasies and his agonised stay in Cambridge as he is for his mathematical genius.

Indians can be excellent geeks, as demonstrated by the tongue-tied astrophysicist Raj Koothrappalli in the US sitcom Big Bang Theory; but the Nobel prize can only be aspired to by Sheldon Cooper, the super-geek and genius in the series, for whom Raj's country of origin is a diverting enigma, and miles away from the popular myth of science on which – along with solid scientific background research – Big Bang Theory is dependent.

Bose didn't get the Nobel prize; nor did his contemporary and namesake, J C Bose, whose contribution to radio waves and the fashioning of the wireless predates Marconi's. The only Indian scientist to get a Nobel prize is the physicist C V Raman, for his work on light at Kolkata University, called the Raman effect. Other Indians have had to become Americans to get the award.

Conditions have always been inimical to science in India, from colonial times to the present day; and despite that, its contributions have occasionally been huge. Yet non-western science (an ugly label engendered by the exclusive nature of western popular imagination) is yet to find its Rosalind Franklin, its symbol of paradoxical success. Unlike Franklin, however, these scientists were never in a race that they lost; they simply came from another planet.

Monday 12 September 2011

Was Isaac Newton A 9/11 Conspiracy Theorist?


By Robin Davis
11 September, 2011
Countercurrents.org

Strange isn't it? To be labelled a 9/11 "conspiracy theorist" you don't even
need to have a theory. It's enough to express any doubt about the official
version of events.

Stranger still, those who consider themselves too wise to entertain such
"nonsense" forget that they, too, are conspiracy theorists. They either
believe the official version, which by definition is a conspiracy theory, or
they have no view. But having no view doesn't let them off the hook. The 911
events had to be caused by a conspiracy of some sort. So, just to
acknowledge that 911 happened is to be a conspiracy theorist.

So, what's really going on here? Could it be that those dismissive of
alternative views are so short on knowledge and the inclination to acquire
it that they have nothing to contribute but ridicule? Could it be that they
simply don't care? Could it be that alternative views are so scary that it's
safer to stifle debate? Could it be simply easier to go with the flow than
to risk the discomfort inflicted upon those who doubt the status quo?
My doubt and discomfort began as it happened, ten years ago while I watched
the towers come down on TV.

I'm not a physicist, but I can do simple maths. Simple maths tells me that a
building can't fall at close to free fall speed unless all but the tiniest
resistance posed by the structure below has first been removed.
I wonder if they called Isaac Newton a conspiracy theorist when that apple
hit him on the noggin and he started babbling about something called
gravity? Probably.

Ask yourself: Could the aircraft impacts and jet fuel fires really render
the structures so feeble that they offered little more resistance than air?
If common sense doesn't provide the answer, do a little research and you'll
find that it couldn't. And if it couldn't, the whole official narrative
falls apart as quickly as the buildings.

If, since 2001, you haven't watched a video of the three towers (yes, three)
coming down, do so again. Just watch. Really watch. Use your stopwatch if
you like. Do some simple maths (the acceleration of gravity is 9.81 metres
per second/per second).

Consider the structures - marvels of architectural engineering. Picture the
thousands of tonnes of steel beams and girders that held those buildings up
for decades. Watch those thousands of tonnes of steel beams and girders
offering next to no resistance as the buildings come down, defying the laws
of physics if the official explanation is to be believed - not once, but
three times in one day.

There's more, much more, and the implications are horrific. Just how
horrific will be all too obvious when future generations marvel at how
easily and eagerly so many were deceived.

Some of us would rather not wait for the bright light of hindsight. Call us
"conspiracy theorists" or "thruthers" or nut cases if you like, but know
that all we want is the truth, because without truth there can be no
justice.

Anything less dishonours the people killed on that day and the millions
killed, maimed, demonised, kidnapped, imprisoned, tortured, widowed,
orphaned, traumatised, and made homeless in the wars raging still in their
name and ours.

Robin Davis lives in Victoria, Australia. He is a freelance writer and
graphic designer. He can be contacted at: robindavis@hotkey.net.au