Step on

After the riots, the surge of opinion and analysis. As Aditya Chakrabortty observed in today's Guardian, this week's mayhem has acted like a tumultuous Rorschach Test in which everyone can see what they want to see. So, three quick thoughts on the week's events (please take 'nothing can justify', 'London is the poorer' and 'in a very real way, we are all guilty' as read):

As any halfway-decent engineer understands, suspension bridges wobble worst when crowds fall into step: the unified pace amplifies the sway, and bridges become perilous. This natural tendency to lock step scuppered the Millennium Bridge in 2000, and a sign on Albert Bridge still warns troops to break step. Social networking enabled the rioters to converge and focus their looting, but enabled the clean-up too. The cumulative impact was dramatic: just as rioters overwhelmed the police, volunteer street cleaners swamped Hackney and had to be redirected to Clapham Junction. The capacity of social networks to foment groupthink makes for a queasy feeling, like being on a ship that lurches, as its passengers rush first one way then another. This alleged anarchy was built upon systems and herd mentality.

The roll-call of closed roads on Tuesday's radio bulletins gave a trivial taste of what is must be like to live in a war zone, never sure from one morning to the next what districts remain intact. It showcased the precariousness of urban life: the actions of a few hundred teenagers can quickly disrupt the delicately-balanced metabolism of the ecosystem (as can a few days' fuel blockade, or a heavy snowfall). But Tuesday also showed the resilience of that ecosystem: people picked their way past burnt-out buildings to the tube, and shops continued to operate from behind smashed windows.

Finally, the riots may not have been explicitly political, but they were about power. Or at least about powerlessness. It may be as futile as it is presumptuous to speculate about individual rioters' motives, but it is not hard to read into the faces captured on CCTV the euphoric rush of suddenly and surprisingly being in control - of your life, of your neighbourhood, of your scared fellow citizens. The price to be paid for those moments will be harsh, but will the violent euphoria prove addictive?