Weeknotes 72 - The 2 meter rule isn’t magic
- I repaid my student loan. It’s not quite as big a deal as getting the divorce or the citizenship but nonetheless it warranted a celebration in the form of a smoky fake-meat burger.
- Despite only leaving the house once a week, wearing a mask when I do and keeping well away from other people I caught a cold. Luckily two days of naps and taking it easy was enough to get over it, but still, where did it come from?
- On one of my weekly bike rides I saw a cyclist pull up very close to another cyclist at a junction and sneeze. Neither were wearing masks.
- On the most recent bike ride it was clear that lockdown’s over. I saw many large groups of people hanging out close to one another, playing basketball etc.
- The 2 meter rule isn’t magic. Depending on air flow and the speed of the cyclist, runner or a person on a motorbike the safe distance behind them could be much longer than 2m. This paper on transmission suggests that while droplets tend to fall to the ground beyond the 2m distance, aerosols (which are smaller) can hang in the air and be carried by air flow or build up in a smaller space. Two super-spreader events show that in indoor spaces with aircon there might not be a safe distance at all if the virus can be carried from one person to another through ventilation. I find it frustrating that the public messaging focuses on the proposed solution (keep some distance) instead of explaining why and when this approach is likely to work, and when it’s not.
- Unless masks become mandatory in public places and indoors I won’t be going anywhere, for all the reasons states above. Wearing one is only a minor inconvenience. I honestly don’t understand why we’re dragging our feet on making them compulsory during a public health crisis. “If at least sixty per cent of the population wore masks that were just sixty-per-cent effective in blocking viral transmission […] the epidemic could be stopped” — need more? John Gruber looked in detail at the science we have to date.