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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A new German law wants to force mothers to reveal their child’s biological father

The so-called “milkmen’s kids law” would seek protection for men who feel they have been duped into raising children they believe are not biologically theirs – at the expense of women’s rights.

The German press call them “Kuckuckskinder”, which translates literally as “cuckoo children” – parasite offspring being raised by an unsuspecting innocent, alien creatures growing fat at the expense of the host species’ own kind. The British press have opted for the more Benny Hill-esque “milkmen’s kids”, prompting images of bored Seventies housewives answering the door in negligées before inviting Robin Asquith lookalikes up to their suburban boudoirs. Nine months later their henpecked husbands are presented with bawling brats and the poor sods remain none the wiser.

Neither image is particularly flattering to the children involved, but then who cares about them? This is a story about men, women and the redressing of a legal – or is it biological? – injustice. The children are incidental.

This week German Justice Minister Heiko Maas introduced a proposal aimed at to providing greater legal protection for “Scheinväter” – men who are duped into raising children whom they falsely believe to be biologically theirs. This is in response to a 2015 case in which Germany’s highest court ruled that a woman who had told her ex-husband that her child may have been conceived with another man could not be compelled to name the latter. This would, the court decided, be an infringement of the woman’s right to privacy. Nonetheless, the decision was seen to highlight the need for further legislation to clarify and strengthen the position of the Scheinvater.

Maas’ proposal, announced on Monday, examines the problem carefully and sensitively before merrily throwing a woman’s right to privacy out of the window. It would compel a woman to name every man she had sexual intercourse with during the time when her child may have been conceived. She would only have the right to remain silent in cases should there be serious reasons for her not to name the biological father (it would be for the court to decide whether a woman’s reasons were serious enough). It is not yet clear what form of punishment a woman would face were she not to name names (I’m thinking a scarlet letter would be in keeping with the classy, retro “man who was present at the moment of conception” wording). In cases where it did transpire that another man was a child’s biological father, he would be obliged to pay compensation to the man “duped” into supporting the child for up to two years.

It is not clear what happens thereafter. Perhaps the two men shake hands, pat each other on the back, maybe even share a beer or two. It is, after all, a kind of gentlemen’s agreement, a transaction which takes place over the heads of both mother and child once the latter’s paternity has been established. The “true” father compensates the “false” one for having maintained his property in his absence. In some cases there may be bitterness and resentment but perhaps in others one will witness a kind of honourable partnership. You can’t trust women, but DNA tests, money and your fellow man won’t let you down.

Even if it achieves nothing else, this proposal brings us right back to the heart of what patriarchy is all about: paternity and ownership. In April this year a German court ruled that men cannot be forced to take paternity tests by children who suspect them of being their fathers. It has to be their decision. Women, meanwhile, can only access abortion on demand in the first trimester of pregnancy, and even then counselling is mandatory (thereafter the approval of two doctors is required, similar to in the UK). One class of people can be forced to gestate and give birth; another can’t even be forced to take a DNA test. One class of people can be compelled to name any man whose sperm may have ventured beyond their cervix; another is allowed to have a body whose business is entirely its own. And yes, one can argue that forcing men to pay money for the raising of children evens up the score. Men have always argued that, but they’re wrong.

Individual men (sometimes) pay for the raising of individual children because the system we call patriarchy has chosen to make fatherhood about individual ownership. Women have little choice but to go along with this as long as men exploit our labour, restrict our access to material resources and threaten us with violence. We live in a world in which it is almost universally assumed that women “owe” individual men the reassurance that it was their precious sperm that impregnated us, lest we put ourselves and our offspring at risk of poverty and isolation. Rarely do any of us dare to protest. We pretend it is a fair deal, even that reproductive differences barely affect our lives at all. But the sex binary – the fact that sperm is not egg and egg is not sperm – affects all of us.

The original 2015 ruling got it right. The male demand for reassurance regarding paternity is an infringement of a woman’s right to privacy. Moreover, it is important to see this in the context of all the other ways in which men have sought to limit women’s sexual activity, freedom of movement and financial independence in order to ensure that children are truly “theirs”.  Anxiety over paternity is fundamentally linked to anxiety over female sexuality and women’s access to public space. Yet unless all women are kept under lock and key at all times, men will never, ever have the reassurance they crave. Even then, the abstract knowledge that you are the only person to have had the opportunity to impregnate a particular woman cannot rival the physical knowledge of gestation.

We have had millennia of pandering to men’s existential anxieties and treating all matters related to human reproduction, from sex to childbirth, as exceptional cases meaning women cannot have full human rights. Isn’t it about time we tried something new? How about understanding fatherhood not as winning gold in an Olympic sperm race, but as a contract endlessly renewed?

What each of us receives when a child is born is not a biological entity to do with as we choose. It is a relationship, with all of its complexities and risks. It is something worth contributing to and fighting for. Truly, if a man cannot understand that, then any money wasted on a Kuckuckskind – a living, breathing child he could get to know – has got to be the least of his worries. 

Glosswitch is a feminist mother of three who works in publishing.