We still don’t really know how bicycles work

Forget mysterious dark matter and the inexplicable accelerating expansion of the universe; the bicycle represents a far more embarrassing hole in the accomplishments of physics.

Let’s be honest, a bit of the pleasure at Chris Froome’s victory in the Tour de France is down to this being our second victory in a row and to the thought that the French haven’t won it since 1985. What must be worse for them, though, is that when it comes to the science of team cycling, even the Belgians are in front.
 
At the University of Mons, researchers are developing something called the Anaconda. It’s never going to be much of a speed machine because it is, in effect, a chain of monocycles with handlebars. These units are connected, by means of hinges that allow them to snake along, to a normal two-wheeled bike at the front. Every rider in the chain can be going in a slightly different direction, which means it takes an enormous amount of control and collaboration to move the thing forward. According to Olivier Verlinden, chief engineer on the project, the main qualification for riders is to be unafraid of falling off.
 
It’s fun, apparently. The idea is to unleash it as a beach-resort bike, the kind of thing that stag and hen parties will use to terrorise seaside towns across the world. But it is also scientifically interesting. Why? Because we still don’t really know how bicycles work.
 
It is rare that most people appreciate the bicycle, but it is quite an extraordinary machine. Push a riderless bike, letting it roll freely at high enough speeds, and it can withstand pushes from the side – it will wobble a little, but quickly recover. In the conventional analysis, that is because the gyroscopic force of the front wheel, its mass and the spontaneous turn of the handlebars all act together to keep the bicycle rolling forwards. This has something to do with the gyroscopic effect, the force that keeps a spinning top upright. You can feel this by removing a wheel from your pushbike and spinning it while you hold the axle spindles. If you try to change the orientation of the wheel, you’ll feel it push back against you.
 
The first mathematical analysis of bicycles suggested that this is also what keeps a moving bike on its wheels. But although the equations were written down in 1910, physicists always had nagging doubts about whether this was the whole story.
 
The most definitive analysis came exactly a century later. It involved an experimental bicycle that had all its gyroscopic effects cancelled out by a system of counter-rotating wheels. The effort of building such a strange contraption was worth it: the resulting paper was published the prestigious journal Science.
 
The publication plunged bicycle dynamics back into chaos. It turns out that taking into account the angles of the headset and the forks, the distribution of weight and the handlebar turn, the gyroscopic effects are not enough to keep a bike upright after all. What does? We simply don’t know. Forget mysterious dark matter and the inexplicable accelerating expansion of the universe; the bicycle represents a far more embarrassing hole in the accomplishments of physics.
 
And it may not be solved any time soon; very few researchers are working full-time on bicycle dynamics and there’s very little money in it. Once we’ve discovered exactly how these contraptions work, it might be possible to come up with bold new designs of bicycle – perhaps even better than the Anaconda. But nobody is desperate for that to happen; not even the French.
 
Maybe that’s OK. In an age where we have worked out the history of the cosmos and the secret of life, it’s rather nice that the humble bicycle keeps our feet on the ground. 
 
Cyclists during the Tour de France. Photo: Getty

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 29 July 2013 issue of the New Statesman, Summer Double Issue

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Erdogan’s purge was too big and too organised to be a mere reaction to the failed coup

There is a specific word for the melancholy of Istanbul. The city is suffering a mighty bout of something like hüzün at the moment. 

Even at the worst of times Istanbul is a beautiful city, and the Bosphorus is a remarkable stretch of sea. Turks get very irritated if you call it a river. They are right. The Bosphorus has a life and energy that a river could never equal. Spend five minutes watching the Bosphorus and you can understand why Orhan Pamuk, Turkey’s Nobel laureate for literature, became fixated by it as he grew up, tracking the movements of the ocean-going vessels, the warships and the freighters as they steamed between Asia and Europe.

I went to an Ottoman palace on the Asian side of the Bosphorus, waiting to interview the former prime minister Ahmet Davu­toglu. He was pushed out of office two months ago by President Recep Tayyip Erdogan when he appeared to be too wedded to the clauses in the Turkish constitution which say that the prime minister is the head of government and the president is a ceremonial head of state. Erdogan was happy with that when he was prime minister. But now he’s president, he wants to change the constitution. If Erdogan can win the vote in parliament he will, in effect, be rubber-stamping the reality he has created since he became president. In the days since the attempted coup, no one has had any doubt about who is the power in the land.

 

City of melancholy

The view from the Ottoman palace was magnificent. Beneath a luscious, pine-shaded garden an oil tanker plied its way towards the Black Sea. Small ferries dodged across the sea lanes. It was not, I hasten to add, Davutoglu’s private residence. It had just been borrowed, for the backdrop. But it reminded a Turkish friend of something she had heard once from the AKP, Erdogan’s ruling party: that they would not rest until they were living in the apartments with balconies and gardens overlooking the Bosphorus that had always been the preserve of the secular elite they wanted to replace.

Pamuk also writes about hüzün, the melancholy that afflicts the citizens of Istanbul. It comes, he says, from the city’s history and its decline, the foghorns on the Bosphorus, from tumbledown walls that have been ruins since the fall of the Byzantine empire, unemployed men in tea houses, covered women waiting for buses that never come, pelting rain and dark evenings: the city’s whole fabric and all the lives within it. “My starting point,” Pamuk wrote, “was the emotion that a child might feel while looking through a steamy window.”

Istanbul is suffering a mighty bout of something like hüzün at the moment. In Pamuk’s work the citizens of Istanbul take a perverse pride in hüzün. No one in Istanbul, or elsewhere in Turkey, can draw comfort from what is happening now. Erdogan’s opponents wonder what kind of future they can have in his Turkey. I think I sensed it, too, in the triumphalist crowds of Erdogan supporters that have been gathering day after day since the coup was defeated.

 

Down with the generals

Erdogan’s opponents are not downcast because the coup failed; a big reason why it did was that it had no public support. Turks know way too much about the authoritarian ways of military rule to want it back. The melancholy is because Erdogan is using the coup to entrench himself even more deeply in power. The purge looks too far-reaching, too organised and too big to have been a quick reaction to the attempt on his power. Instead it seems to be a plan that was waiting to be used.

Turkey is a deeply unhappy country. It is hard to imagine now, but when the Arab uprisings happened in 2011 it seemed to be a model for the Middle East. It had elections and an economy that worked and grew. When I asked Davutoglu around that time whether there would be a new Ottoman sphere of influence for the 21st century, he smiled modestly, denied any such ambition and went on to explain that the 2011 uprisings were the true succession to the Ottoman empire. A century of European, and then American, domination was ending. It had been a false start in Middle Eastern history. Now it was back on track. The people of the region were deciding their futures, and perhaps Turkey would have a role, almost like a big brother.

Turkey’s position – straddling east and west, facing Europe and Asia – is the key to its history and its future. It could be, should be, a rock of stability in a desperately un­stable part of the world. But it isn’t, and that is a problem for all of us.

 

Contagion of war

The coup did not come out of a clear sky. Turkey was in deep crisis before the attempt was made. Part of the problem has come from Erdogan’s divisive policies. He has led the AKP to successive election victories since it first won in 2002. But the policies of his governments have not been inclusive. As long as his supporters are happy, the president seems unconcerned about the resentment and opposition he is generating on the other side of politics.

Perhaps that was inevitable. His mission, as a political Islamist, was to change the country, to end the power of secular elites, including the army, which had been dominant since Mustafa Kemal Atatürk created modern Turkey after the collapse of the Ottoman empire. And there is also the influence of chaos and war in the Middle East. Turkey has borders with Iraq and Syria, and is deeply involved in their wars. The borders do not stop the contagion of violence. Hundreds of people have died in the past year in bomb attacks in Turkish cities, some carried out by the jihadists of so-called Islamic State, and some sent by Kurdish separatists working under the PKK.

It is a horrible mix. Erdogan might be able to deal with it better if he had used the attempted coup to try to unite Turkey. All the parliamentary parties condemned it. But instead, he has turned the power of the state against his opponents. More rough times lie ahead.

Jeremy Bowen is the BBC’s Middle East editor. He tweets @bowenbbc

This article first appeared in the 28 July 2016 issue of the New Statesman, Summer Double Issue