Daily Archives: April 1, 2020
Stay at home. Keep your distance from anyone: the UK prescribed distance is two metres. Actually (to be fair) UK lockdown restrictions – unlike the pork-barrel that’s gone full-blown Operation Bernhard – make quite a lot more sense than many other countries, or than the UK itself under Foot&Mouth in 2001.
How much protection does distance offer? Your guess is as good as mine, which may or may not in turn be as good as TPTB’s. But can we find any yardsticks from everyday life?
Intuitively, two metres is the kind of distance at which you won’t be knocked hard by smells like a fresh dog or horse mess, or indoors a baby that needs changing. So far, so good.
But coronavirus is, we’re told, much more dangerous than such everyday bad smells. We do have a yardstick for small volumes of something much nastier than excrement: the area blighted by a smoker. Clearly there two metres is wholly inadequate. Twenty metres might be more realistic in average weather conditions, but at times even two hundred can be insufficient. And it’ll routinely invade the home from outside, through doors, windows, cracks, … Whoops – that makes an altogether less-reassuring yardstick for dispersal of airborne hazards!
But it’s not just safe distances for which we might seek the reassurance (or otherwise) of familiar yardsticks. We can look for yardsticks for prevalence and infectiousness. I first contemplated this post several days ago and had in mind to play with some parametric studies of such issues (once upon a time I had “mathematician” in my job title and did such things professionally), but it seems the news is moving faster than me, and we’re now hearing from better-informed people like new superstar Neil Ferguson and regular media-favourite credible statistician David Spiegelhalter. So I’ll defer there.
Ferguson was on t’wireless recently, when the official UK infection count was just over 20k confirmed cases, but suggesting the real figure might be as high as 2 million. That’s an interesting contrast, and totally plausible. One in thirty of the overall population is, after all, still lower than some known (albeit unrepresentative) samples we could take, like the Cabinet 😉 Two million would be not merely interesting but rather encouraging: it would indicate rapidly spreading population-immunity, and make an antibody test all the more interesting to, well, more-or-less anyone who’s had a lurgy this year. Though it wouldn’t necessarily indicate a lower-than-expected death rate, ‘cos it’s also emerged that our figures count only deaths in hospital, not anyone outside unless a post-mortem is held.
Speaking as one of those who has indeed had a recent lurgy, I’d now really love to get that antibody test myself. Was it a very mild case of the dreaded corona, or a mild-ish regular lurgy? The latter is much more likely: today’s briefing told us that only one in six actual tests has proved positive (25k of 150k), and the sample of people tested is those with the symptoms rather than the general population. But to have had it would turn me from a high-risk person advised to stay home (and, erm, get a coronary instead), to a person safe to resume social life and indeed volunteer to help out those who need it.
Short of that, proper population statistics would be highly informative and would enable us all to reevaluate our personal risks. Sadly our super-bureaucratic powers-that-be seem to be quite a way behind leading countries in being able to test or produce meaningful statistics on the general population, and intent on reinventing wheels such as the tracking app that has apparently been so successful in South Korea.
Ho, hum. Whatever I say here will soon be overtaken by events.