windwalker wrote:
Well. First of all back to basics, as regards physics (and then masks).
There are two basic physical situations when it comes to (large) groups of people congregating in public spaces.
Outdoors and indoors.
Outdoors/outside: air is not trapped in an enclosed space, moreover there is quite often a breeze or wind moving the air away. Basically each person has a huge amount of air volume for themselves if you include “upwards”. In the garden, in the park, on the sports field, on the street (if not packed), on a café terrace etc. Low risk of getting a significant dose of droplets or aerosols from each other as long as you don’t stand toe to toe and face to face and repeatedly go “Haaaaaah!”
Indoors/inside: air is more or less trapped in an enclosed space unless many windows are open (and there is some kind of breeze or wind). Basically each person has a limited amount of air volume for themselves – sometimes extremely limited. In waiting rooms, in clubs, restaurants, bars, cafés, canteens, in gyms, sports halls, dojos, in public transport, in classrooms, in offices, in theater and cinema auditoriums, in enclosed stadiums, at trade fairs, in many shops etc. Depending on circumstances and time spent in the confined space, a significantly higher risk of getting a significant dose of droplets or aerosols from each other, even if you don’t stand face to face with someone. Aerosols can often build up and circulate within the space faster than they can be ventilated out.
A borderline case is presented by events with mass attendance where very large numbers of people spend hours in close proximity to each other (especially without masks), either outside or (probably more risky) in a semi-covered stadium. More hazardous regarding infection than most group outdoor activities, less hazardous than being in enclosed spaces in larger or smaller groups.
The picture posted by Windwalker, showing people sitting outdoors at café tables, is a low-hazard situation. In principle it could have been taken in many European countries. In Germany, this is how we sit at outdoor café tables, too. There is no mandate or even advice to wear masks in such a situation, although of course you can if you want. Masks are however still compulsory for public transport and for shops/stores. Many people wear them in other outdoor public space situations where there are so many people it’s difficult to maintain 1.5 m distancing.
Are the scientists in Holland wrong?
Controversial. We are talking here about one team of scientists who have been advising the government over recent months. Not about all scientists with relevant expertise in the Netherlands, some of whom disagree with the gov. advisory team. A few days ago I posted something about the political/cultural attitude of the current Dutch government as regards mask-wearing. The advisory team might be right. They might also be wrong. Or somewhere in between. Other 'relevant' scientists in the Netherlands and certainly many in other countries are of a different opinion, indeed the majority of relevant scientists globally, now tend towards the opinion of "it helps mitigate" or "still uncertain, but the potential benefits outweigh the potential harm". So are they wrong? The question as asked isn't really helpful or useful.
The first reader comment added to the Daily Mail article:
Meanwhile, in the real world, the Netherlands, with twice the population of Austria, has more than 8 times the number of deaths as Austria which DOES have a mask wearing policy. Sweden, which also has no mandatory mask wearing, has more than 8 times the number of deaths with just a million more people than Austria. But who cares? They're mostly old people right? "It is perfectly possible to ignore reality. It is not possible to ignore the consequences of ignoring reality." Neoliberal icon Ayn RandNot saying that this comment is 'right' either. Each country has other different factors that make a direct comparsion difficult. But it shows that no-one can currently make any definitive statements on masks. Apart from the fact that we all dislike wearing them. I certainly do, and I'm always glad to get the thing off again. Still wear in certain situations though: shops, buses and trains, other public buildings, when engaging in/teaching tuishou and sparring, even when outdoors.