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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"We repealed, then forgot": the long shadow of Section 28 homophobia

Why are deeply conservative views about the "promotion" of homosexuality still being reiterated to Scottish school pupils? 

Grim stories of LGBTI children being bullied in school are all too common. But one which emerged over the weekend garnered particular attention - because of the echoes of the infamous Section 28, nearly two decades after it was scrapped.

A 16-year-old pupil of a West Lothian school, who does not wish to be named, told Pink News that staff asked him to remove his small rainbow pride badge because, though they had "no problem" with his sexuality, it was not appropriate to "promote it" in school. It's a blast from the past - the rules against "promoting" homosexuality were repealed in 2000 in Scotland, but the long legacy of Section 28 seems hard to shake off. 

The local authority responsible said in a statement that non-school related badges are not permitted on uniforms, and says it is "committed to equal rights for LGBT people". 

The small badge depicted a rainbow-striped heart, which the pupil said he had brought back from the Edinburgh Pride march the previous weekend. He reportedly "no longer feels comfortable going to school", and said homophobia from staff members felt "much more scar[y] than when I encountered the same from other pupils". 

At a time when four Scottish party leaders are gay, and the new Westminster parliament included a record number of LGBTQ MPs, the political world is making progress in promoting equality. But education, it seems, has not kept up. According to research from LGBT rights campaigners Stonewall, 40 per cent of LGBT pupils across the UK reported being taught nothing about LGBT issues at school. Among trans students, 44 per cent said school staff didn’t know what "trans" even means.

The need for teacher training and curriculum reform is at the top of campaigners' agendas. "We're disappointed but not surprised by this example," says Jordan Daly, the co-founder of Time for Inclusive Education [TIE]. His grassroots campaign focuses on making politicians and wider society aware of the reality LGBTI school students in Scotland face. "We're in schools on a monthly basis, so we know this is by no means an isolated incident." 

Studies have repeatedly shown a startling level of self-harm and mental illness reported by LGBTI school students. Trans students are particularly at risk. In 2015, Daly and colleagues began a tour of schools. Shocking stories included one in which a teacher singled out a trans pupils for ridicule in front of the class. More commonly, though, staff told them the same story: we just don't know what we're allowed to say about gay relationships. 

This is the point, according to Daly - retraining, or rather the lack of it. For some of those teachers trained during the 1980s and 1990s, when Section 28 prevented local authorities from "promoting homosexuality", confusion still reigns about what they can and cannot teach - or even mention in front of their pupils. 

The infamous clause was specific in its homophobia: the "acceptability of homosexuality as a pretended family relationship" could not be mentioned in schools. But it's been 17 years since the clause was repealed in Scotland - indeed, it was one of the very first acts of the new Scottish Parliament (the rest of the UK followed suit three years later). Why are we still hearing this archaic language? 

"We repealed, we clapped and cheered, and then we just forgot," Daly says. After the bitter campaign in Scotland, in which an alliance of churches led by millionaire businessman Brian Souter poured money into "Keeping the Clause", the government was pleased with its victory, which seemed to establish Holyrood as a progressive political space early on in the life of the parliament. But without updating the curriculum or retraining teaching staff, Daly argues, it left a "massive vacuum" of uncertainty. 

The Stonewall research suggests a similar confusion is likely across the UK. Daly doesn't believe the situation in Scotland is notably worse than in England, and disputes the oft-cited allegation that the issue is somehow worse in Scotland's denominational schools. Homophobia may be "wrapped up in the language of religious belief" in certain schools, he says, but it's "just as much of a problem elsewhere. The TIE campaign doesn't have different strategies for different schools." 

After initial disappointments - their thousands-strong petition to change the curriculum was thrown out by parliament in 2016 - the campaign has won the support of leaders such as Nicola Sturgeon and Kezia Dugdale, and recently, the backing of a majority of MSPs. The Scottish government has set up a working group, and promised a national strategy. 

But for Daly, who himself struggled at a young age with his sexuality and society's failure to accept it, the matter remains an urgent one.  At just 21, he can reel off countless painful stories of young LGBTI students - some of which end in tragedy. One of the saddest elements of the story from St Kentigern's is that the pupil claimed his school was the safest place he had to express his identity, because he was not out at home. Perhaps for a gay pupil in ten years time, that will be a guarantee. 

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