A room, a bar and a classroom: how the coronavirus is spread through the air

I saw this shared many times last week, it's an excellent visualisation of various social situations to illustrate just how quickly the virus can spread.

The modelling assumes a worst case scenario, but it's one of the best examples I've seen. As much as we miss eating out and socialising why would you bother if the risk to your health could be so high?

And why aren't masks mandatory in the UK? In all the examples, the number of infections falls by half with that one act of kindness. Until we change our habits, it's not going to get any better, is it?