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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The government must demand that Iran release Nazanin Zaghari-Ratcliffe

Iran's imprisonment of my constituent breaches the Convention on the Rights of the Child.

I grew up with a very paranoid mother. She had tragically lost members of her family as a teenager and, as a result, she is extremely fearful when it came to her children. I used to laugh at her growing up – I indulged it but often scoffed at her constant need to hear from us.

A few days ago, I was in Parliament as normal. My husband, his parents and our baby daughter were all in Parliament. This rare occasion had come about due to my mother in law’s birthday – I thought it would be a treat for her to lunch in the Mother of Parliaments!

The division bells rang half way through our meal and I left them to vote, grabbing my phone of the table. “See you in ten minutes!” I told them. I didn’t see them for more than five hours.

The minute the doors bolted and the Deputy Speaker announced that we were indefinitely being kept safe in the chamber, all I could think about was my daughter. In my heart of hearts, I knew she was safe. She was surrounded by people who loved her and would protect her even more ferociously than I ever could.

But try explaining that to a paranoid mother. Those five hours felt like an eternity. In my head, I imagined she was crying for me and that I couldn’t be there for her while the building we were in was under attack. In reality, I later found out she had been happily singing Twinkle Twinkle little star and showing off her latest crawl.

That sense of helplessness and desperate impatience is hard to describe. I counted down the minutes until I could see her, as my imagination ran away with me. In those 5 hours, I started thinking more and more about my constituent Nazanin Zaghari-Ratcliffe.

Here I was, temporarily locked in the Parliamentary chamber, surrounded by friends and colleagues and door keepers who were doing all they could to keep me safe. I knew I was going to be let out eventually and that I would be reunited with my daughter and husband within hours.

Nazanin has been detained in the notorious Evin prison in Iran for nearly a year. She only gets an occasional supervised visit with her two-year-old daughter Gabriella. She’s missed Christmas with Gabriella, she missed Gabriella’s second birthday and no doubt she will be missing Mother’s Day with Gabriella.

But it’s not just the big occasions, it’s the everyday developments when Gabriella learns a new song, discovers a new story, makes a new friend. Those are the important milestones that my mother never missed with me and the ones I want to make sure I don’t miss with my daughter.

Unfortunately, Nazanin is just one of many examples to choose from. Globally there are more than half a million women in prison serving a sentence following conviction, or are awaiting trial. Many of these women are mothers who have been separated from their children for years.

In 2010, the United Nations General Assembly unanimously adopted the Bangkok Rules - the first international instrument to explicitly address the different needs that female prisoners have. It was also the first instrument to outline safeguards for the children of imprisoned mothers.

The Bangkok Rules apply to all women prisoners throughout all stages of the criminal justice system, including before sentencing and after release. However, Nazanin’s case has seen a wilful flouting of the rules at each and every stage.

Rule 23 states that ‘Disciplinary sanctions for women prisoners shall not include a prohibition of family contact, especially with children’. Tell that to her daughter, Gabriella, who has barely seen her mother for the best part of a year.

Rule 26 adds that women prisoners’ contact with their families shall be facilitated by all reasonable means, especially for those detained in prisons located far from their homes. Tell that to her husband, Richard, who in almost a year has only spoken to his wife via a few calls monitored by the Iranian Revolutionary Guard.

Iran has ratified the Convention on the Rights of the Child and supported the Bangkok Rules, yet it is breaching both with its treatment of Nazanin. It is therefore incumbent upon our government to take the formal step of calling for Nazanin's release - it is staggering they have not yet done so.

As I pass the window displays in shops for Mother’s Day, most of the cards have messages centred around ‘making your mother happy’. If there’s one mother I’d like to make happy this year, it’s Nazanin Zaghari-Ratcliffe.

Tulip Siddiq is Labour MP for Hampstead and Kilburn