There’s one thing I really don’t get about the very idea of bluetooth-powered contact tracing. Let’s say we did develop a really decent app. Let’s say the protocol is secure, and the app works really well, and privacy is respected, and everything is perfect on that side of things. It’s hardly possible, but just for the sake of argument let’s say it’s all good.
So, I have the app, you have the app. Let’s say you’re COVID-19 positive, and our apps have correctly identified that our phones have been in close proximity to each other for an hour. Like, a meter apart. So, supposedly me and you, our physical bodies, were close in space for that period of time. And in fact we were.
Because I was sitting on my couch listening to a podcast while you were banging your lover on her couch, and your lover’s couch happens to be positioned close to the wall that separates my apartment from your lover’s apartment, and my couch happens to be positioned along the same wall on my side.
How do the apps know that there was a wall between us, and that the two apartments don’t even share the same stairwell, so we had no chance to bump into each other and transmit the virus at all?