May the force not be with you: Sandra Bullock goes for a spacewalk in Gravity. Photo: Warner Bros
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In search of the notorious Big G: why we still know so little about gravity

Gravity is pathetic and so is our understanding of it.

Gravity is pathetic. The Oscar statuette, for instance, has a mass of 3.85 kilograms but it is pulled down to earth by a force so weak that you can buy a £2.99 fridge magnet that can beat it. It’s shameful that the gravitational pull of the entire earth can be overcome by a cheap piece of magnetised steel.

Gravity is by far the weakest of the fundamental forces of nature (the fridge magnet puts the far stronger electromagnetic force to work). It is so weak that its strength is proving difficult to measure accurately. In late February, while Alfonso Cuarón, the director of the sci-fi film Gravity, was on tenterhooks waiting for the Oscars result, the world’s experts on gravity assembled just outside Milton Keynes in an attempt to sort out this most embarrassing problem.

Numbers such as the strength of gravity, the speed of light and the charge on an electron are known to physicists as the “fundamental constants”. They are in some ways the sticking plaster of physics. We can explain the origin of most things but we know the values of the fundamental constants only by measuring them – there is no way to work them out from a theory.

These days, most are very well defined – but not gravity. It is the only fundamental constant for which our uncertainty over its value has got worse over the years.

The gravitational constant is sometimes known as “Big G”. This differentiates it from “little g”, which describes how fast things accelerate towards Planet Earth when free to fall. The first accurate measurement of Big G was made in 1798. Henry Cavendish used a torsion balance, a device in which two lead weights are attached to the ends of a metal bar. The bar hangs horizontally by a metal wire attached to its midpoint. Cavendish then brought other weights close to one of the lead weights and measured how much the gravitational attraction between the weights twisted the wire. From that measurement, he calculated the strength of gravity.

Cavendish’s accuracy was five parts in 1,000. Over 200 years later, our accuracy stands at roughly one part in 10,000. Given that modern measurements use lasers and electronic devices and Cavendish used a mirror and a candle, it hardly counts as a great improvement.

What’s worse is that our measurements of Big G are getting less accurate. The latest measurement, reported at the end of last year, reduced the overall value by 66 parts per million but the uncertainty
of the value increased from 100 parts per million to 120 parts per million.

The measurement was taken by Terry Quinn, emeritus director of the International Bureau of Weights and Measures in Paris. At its meeting in February, he argued that it was time researchers admitted that everyone must be making some basic errors in their method and that they should give up on making any more unilateral measurements.

The experts now agree that future experiments seeking the value of Big G will be done in big collaborations, with the proposals for equipment and methodology being scrutinised by everyone in advance to minimise the chance of further embarrassment.

It will, they say, mimic the way that researchers worked together to find the Higgs boson. That gave us the secret of mass: the hope is that if the physicists all pull together, they can finally work out exactly what size of force brings that mass down to earth.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 05 March 2014 issue of the New Statesman, Putin's power game

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Did your personality determine whether you voted for Brexit? Research suggests so

The Online Privacy Foundation found Leave voters were significantly more likely to be authoritarian and conscientious. 

"Before referendum day, I said the winners would be those who told the most convincing lies," Paul Flynn, a Labour MP, wrote in these pages. "Leave did." The idea that those who voted for Brexit were somehow manipulated is widely accepted by the Remain camp. The Leave campaign, so the argument goes, played on voters' fears and exploited their low numeracy. And new research from the Online Privacy Foundation suggests this argument may, in part at least, be right. 

Over the last 18 months the organisation have researched differences in personality traits, levels of authoritarianism, numeracy, thinking styles and cognitive biases between EU referendum voters. The organisation conducted a series of studies, capturing over 11,000 responses to self-report psychology questionnaires and controlled experiments, with the final results scheduled to be presented at the International Conference on Political Psychology in Copenhagen in October 2017.

The researchers questioned voters using the "Five Factor Model" which consists of five broad personality traits - Openness, Conscientiousness, Extraversion, Agreeableness and Neuroticism. They also considered the disposition of authoritarianism (it is not considered a personality trait). Authoritarians have a more black and white view of the world around them, are more concerned with the upkeep of established societal traditions and have a tendency to be less accepting of outsiders. 

So what did they uncover? Participants expressing an intent to vote to leave the EU reported significantly higher levels of authoritarianism and conscientiousness, and lower levels of openness and neuroticism than voters expressing an intent to vote to remain. (Conscientiousness is associated with dependability, dutifulness, focus and adherence to societal norms in contrast to disorganisation, carelessness and impulsivity.)

Immigration in particular seems to have affected voting. While authoritarians were much more likely to vote Leave to begin with, those who were less authoritarian became increasingly likely to vote Leave if they expressed high levels of concern over immigration. These findings chime with research by the Professors Marc Hetherington and Elizabeth Suhay, which found that Americans became susceptible to "authoritarian thinking" when they perceived a grave threat to their safety. 

Then there's what you might call the £350m question - did Leave voters know what they were voting for? When the Online Privacy Foundation researchers compared Leave voters with Remain voters, they displayed significantly lower levels of numeracy, reasoning and appeared more impulsive. In all three areas, older voters performed significantly worse than young voters intending to vote the same way.

Even when voters were able to interpret statistics, their ability to do so could be overcome by partisanship. In one striking study, when voters were asked to interpret statistics about whether a skin cream increases or decreases a rash, they were able to interpret them correctly roughly 57 per cent of the time. But when voters were asked to interpret the same set of statistics, but told they were about whether immigration increases or decreases crime, something disturbing happened. 

If the statistics didn't support a voter's view, their ability to correctly interpret the numbers dropped, in some cases, by almost a half. 

Before Remoaners start to crow, this study is not an affirmation that "I'm smart, you're dumb". Further research could be done, for example, on the role of age and education (young graduates were far more likely to vote Remain). But in the meantime, there is a question that needs to be answered - are political campaigners deliberately exploiting these personality traits? 

Chris Sumner, from the Online Privacy Foundation, warns that in the era of Big Data, clues about our personalities are collected online: "In the era of Big Data, these clues are aggregated, transformed and sold by a burgeoning industry."

Indeed, Cambridge Analytica, a data company associated with the political right in the UK and US, states on its website that it can "more effectively engage and persuade voters using specially tailored language and visual ad combinations crafted with insights gleaned from behavioral understandings of your electorate". It will do so through a "blend of big data analytics and behavioural psychology". 

"Given the differences observed between Leave and Remain voters, and irrespective of which campaign, it is reasonable to hypothesize that industrial-scale psychographic profiling would have been a highly effective strategy," Sumner says. By identifying voters with different personalities and attitudes, such campaigns could target "the most persuadable voters with messages most likely to influence their vote". Indeed, in research yet to be published, the Online Privacy Foundation targeted groups with differing attitudes to civil liberties based on psychographic indicators associated with authoritarianism. The findings, says Sumner, illustrate "the ease with which individuals' inherent differences could be exploited". 

Julia Rampen is the digital news editor of the New Statesman (previously editor of The Staggers, The New Statesman's online rolling politics blog). She has also been deputy editor at Mirror Money Online and has worked as a financial journalist for several trade magazines. 

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