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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Selfie sticks mask a bigger problem we have with each other – interaction

New services and products, like selfie sticks, ensure we never have to look each other in the eye, or ask for a tiny favour.

Selfie sticks are the worst, there's no denying it. I was so close to having a selfie stick-free weekend wandering around London aimlessly. But I made the mistake of walking across Westminster Bridge and saw plenty in action. And who can blame Londoners and tourists wanting to frame themselves right next to views of parliament or the London Eye on the opposite side? I'm a sucker for excellent views, like anybody else.

Whereas selfies are inherently a necessary evil for all of those apps that require a decent profile picture, the stick takes this indulgence to a whole new level. Before this metal, phone-holding pole became hilariously popular across the globe, we all had to do the unthinkable (prepare to gasp): ask someone to take a photo of us! How strange and good-hearted of us to trust a member of the public with those brilliant point-and-shoot cameras that we've now stuffed in our attics and bedroom drawers.

I can understand using one in a secluded place where there's nobody around. But isn't the reason behind the selfie stick to basically minimise your interaction with others? After all, a human is going to take a better photo of you and your loved one on the Thames, instead of fumbling for the shutter button on the stick and trying to see the screen a few feet away. We've become too afraid and awkward to ask someone for this tiny favour. This level of awkwardness is just being translated into all sorts of stupid goods and services around the world. It's as if the fictional Larry David from Curb Your Enthusiasm is being catered to in so many ways.

Heard of the Breakup Shop? Yes, it sounds exactly what you think it would be about. A company that can send an endearing Snapchat message so you can break up with the person you just took that selfie with. Even the now classic method of using email is too considered and measured. And by that I mean having the courage to send an email yourself, not via a third-party service. What happened to seeing people's faces in the flesh and witnessing how our words affect them? We used to be so caring and thoughtful this way.

But of course, that's a service for something serious a person with no courage could end up using. What about everyday, tedious matters? Silicon Valley has you covered! For example, you can avoid going to the petrol – sorry, gas – station and doing that thing car owners have to do frequently: fill up your tank with fuel. Don't worry, this giant "inconvenience" can now be removed from your life through Purple. What's that? It's a service where you pay for fuel through an app and share your car's location. At some point, a dude-bro (or sister) will pop round and fill up the fuel tank, so long as you remember to leave the cap open. Yes. This is a real thing.

The word convenience comes up very frequently with these superfluous start-ups. I think it all started to go into overdrive after Graze, a snack delivery service, which I can understand because I'd find it hard to make a low-fat cake and only restrict myself to a small cube for the whole week. Certain colleagues of mine are hooked to these sorts of things, so much so that I stick by my claim of Wall-E, in which humans are bolted to self-driving seats unable to move, being potentially the most accurate of all sci-fi films ever made.

However, other start-ups are so flat-out idiotic, you have to question why they exist, like Fetch Coffee. Why would you pay extra to have a Starbucks drink delivered to your door? After all, Starbucks sell that stuff in the supermarkets for you to make yourself when you are at home and away from one of their cafes. Are we simply so annoyed by the act of queuing and recognising each other's existence that we want our morning coffee personally delivered to us in such a wasteful way?

It's pretty simple. We're all becoming fumbling, anxious outcasts, constantly inconvenienced by life itself. We're determined to avoid interaction with others even more than is already possible. No wonder the best YouTube channels are of fellow citizens sharing stories of awkward encounters – they're my favourite too.

The Office, NBC

These are all passive distractions we're happy to engage in, so we can avoid sitting with someone for two minutes and provide, in the words of Dwight Schrute, undivided attention to others. It reminds me of an appearance by Louis CK on Conan O'Brien's American talk show. He says everyone has something inside them that is "forever empty", and we're losing the ability to feel empathy towards others.

The most striking thing about following Adele's re-emergence like a fanboy was the small atom of information saying she had returned to doing her own laundry again after giving up the chore. Perhaps it's time we become happy and content in being able to wash our own clothes, fuel up a car and even ask someone to take a photo of ourselves. It'll make us better people.