New Scientist
by Paul Hazelden

Introduction

I am a regular reader of the magazine, New Scientist, and it regularly contains articles and other items of interest. My intention here is simply to provide an index to some of these so I know where to find them again.

Cosmology's not broken

7 August 2010, 22-23.

Whether or not you are interested in Cosmology, this article makes a very valid plea for probability to be handled correctly within mainstream science.

The basic point is that unlikely events occur frequently, so we should not argue that the probability of this event, given what we know, is low, so what we know is probably wrong; instead we should consider the probability of what we think we know being wrong, given that this event has occurred. This latter calculation will involve many more factors than just the probability of the event, so it gives a much more useful result.

Deadly rationality

28 November 2009, 53.

Review by Michael Bond of Radical, Religious and Violent by Eli Berman (MIT Press).

Looking at religious terrorism. "While other authors have focussed on the obvious but peripheral issue of how religion inspires individual attackers - it is rarely the primary motivation, as many studies have shown - Berman tackes the pertinent question of what makes radical religious organisations so much more deadly than other groups... one key measure of the potential effectiveness or lethality of a group... is the extent to which it provides social services within its community."

"Those whose jobs it is to protect citizens from such attacks should note his conclusion: that the groups behind them are rational operators whose tactics are best countered socially, economically and politically, not with violence."

Down in Flames

4 November 2006, 42-45.

This contains the worrying news that many fires have been wrongly identified as being caused by arson, as many features the experts associated with arson turn out to be produced in accidental fires as well.

It also contains the fascinating detail that you can't set fire to a pool of petrol by dropping a lit cigarette into it, despite what you may have seen in numerous films.

End of spacetime

7 August 2010, 28-31.

For over a hundred years, we have lived with the idea that we live in a universe that has at least four dimensions: three of space and one of time. Relativity shows how space and time are connected, and constitute the single entity of spacetime. This may be about to change.

Petr Horava at the University of California in Berkley is proposing a new interpretation. This could lead to a 'theory of everything' but at the cost of undoing spacetime.

We have known for a long time that Relativity and Quantum Physics are incompatible. Horava suggests two changes to Relativity: first, remove the Lorentz symmetry; and secondly, give time a preferred direction.

Lorentx symmetry has been tested to an astonishing degree of accuracy in many ways, so this is a brave move. But Horava suggests that the symmetry holds at 'normal' distances but disappears when you are working at very small distances, in much the same way as Newton's equations hold at normal speeds but disappear when you go very fast. With this modification, gravity can work at very small distances without contrdicting Quantum Mechanics.

Another benefit from this approach is that it can explain our observations of galaxies without needing to introduce 'dark matter' - a very attractive possibility.

Inevitably, more work is required. But it looks like an interesting possibility.

Evolving gods

28 November 2009, 53.

Review by Amanda Gefter of The Faith Instinct by Nicholas Wade (Penguin).

"Wade argues that in early human societies religion was the best solution to lawlessness within a group and warfare from without, motivating individuals to put society's needs before their own. It's a compelling idea, but it requires natural selection to act on groups as well as individuals - an idea that remains controversial."

"Wade sees a future in which religion serves only its societal functions, stripped of obsolete beliefs in the supernatural. It's hard to reconcile with today, when those who cling to superstition and those who turn to reason seem more polarised than ever."

And it is hard to see how religion can have any function if it is stripped of belief in the supernatural. If you believe there is no God, how do you practice a religion which requires that belief, and how does such a faith motivate you to sacrificial love of your fellow creatures?

This is the key issue Sartre and his fellows struggled with. The best solution they found? "Life is meaningless, but we must live as though it has meaning." But where does this 'must' come from, if morality is only something we invent to make ourselves feel better? You just have to pretend hard enough, and maybe you can convince yourself it is true, even though you know it's not...

Fearlessness may be linked to crime

21 November 2009, 18.

Even at the tender age of 3, children who later go on to be convicted of a crime are less likely to learn to link fear with a certain noise than those who don't. This may mean that an insensitivity to fear could be a driving force behind criminal behaviour.

Adrian Raine of the University of Pennsylvania looked at the data from a study of 1800 3 year olds in the 1970s. They found that 137 of them now had criminal records, and these people had showed significantly less fear than those who did not go on to become criminals, compared to subjects of a similar race, gender, and so on.

It doesn't add up

14 August 2010, 34-38.

Around 1920, David Hilbert suggested that the rules of arithmetic should be complete, consistent and computable. Very reasonable, you would have thought. But in the 1930s, Gödel established that they can't be both complete and consistent; and Turing established that they can't be computable.

This is disturbing stuff, but most people manage to ignore it. After all Gödel's proof uses logical abstractions, which don't really touch on the real world.

But now, Harvey Friedman from Ohio State University is publishing a book (Boolean Relation Theory and Incompleteness) which extends the problem much further: now we know that there are unprovable statements about concrete structures. It touches the real world. The hole in mathematics is much bigger than we thought.

The issue seems to hang on the way in which infinity is handled: it is an essential part of the mathematician's toolbag, but this may not be enough. We may be faced with two contradictory options for how we do maths, and both options seem to be completely unpalatable.

A matter of faith

7 August 2010, 40.

Review by Manjit Kumar of Why Beliefs Matter: Reflections on the nature of science by E Brian Davies (OUP).

Bohr and Einstein did not agree on whether science gives us access to an objective reality. This is as good a starting point as any to examine the role of belief in the practice of science: not just religious belief, but philosophical beliefs and worldviews. What we believe affects how we act and how we perceive the world - whether or not we recognise that this is taking place. As Davies points out: you cannot avoid having a worldview.

From the review, this sounds like a thoughtful and helpful examination of a subject which is often neglected. And he quotes C S Lewis to support his argument!

The time machine in your head

24 October 2009, 32-37.

We all know the 'waggon wheel illusion' in which the wheels on waggons in films appear to go the wrong way at certain speeds. But the same effect occurs in real life, because our brains sample visual images at around 13 frame per second. Continuity of movement is a visual illusion.

Even more strangely, when overlapping shapes spin at around that rate, people often see one pattern reverse independently of the other - so we are not just taking visual snapshots of the world, but processing information about discrete objects within the world as distinct units of mental activity.

Our brains must handle simultaneous input from different senses and interpret them correctly. One aspect of this is to create building blocks of consciousness: if two events fall inside the same block, they are perceived as simultaneous, and if they fall into different blocks, they are preceived as sequential.

But our brains process different signals at different speeds, and it is possible for the timing to get mismatched. The suggestion is that schitzophrenia may arise from a mismatch in the timekeeping and coordinating function of the brain, so that the normal perception of cause preceding effect may be at times reversed.

Experiments also show that our perceptions do not actually speed up when we are under stress, but the memories we capture at such times are 'denser' - we store more memory, so it appears with hindsight that the event lasted longer.