I posted this as a long thread on Twitter. Reposting here for completeness.

I've been notified of a close contact by the COVID19 app. On the the 20th, the only time I went out for long enough was dinner. We (wife+kids) sat at the only outdoor seat of a restaurant. I assume someone inside the restaurant or maybe the bar next door is the contact...

First off, the app only notified me because I opened it. It does not check in the background. Another friend opened it after hearing about this and was immediately notified of a contact. The app has been broken since the start and the developers have been told multiple times...

Anyway, it seems pretty unlikely that I am infected but I did go inside to use the toilet and pay the bill with mask on. I have a bit of a rough throat since last night but that could just be the changing weather...

I phoned the number, gave all the details and now I have an appointment to get a saliva PCR test in 48 hours!

All relatively smooth. Mostly in Japanese. I started with the English helpline last night but they just gave me the number for the Japanese one. |If my Japanese was worse, I don't know what would have happened.

Also, I have to pay for the test (3000Y)! My Japanese is not good enough to have a fight on the phone but I thought this should be free.

More problematic is the outcome...

I'm the only one being tested because I'm the only one with symptoms. Is the app meaningless? They should be testing all or none. Has Japan stopped believing in asymptomatic spread again?

If they actually think I'm at risk, this is day 6-7 which can be highly infectious. Why let me sit at home with my family for another 48 hours before testing? If I'm being tested, I should be tested ASAP, not in 48 hours.

@nishiurah

Also, I was given no instructions about isolating, no questions about my kids' school or my wife. From a test-trace-isolate perspective, this is useless.

Results takes a day or two, so maybe 96 hours from now, I will know.

If my kids are infected then they were probably spreading in school on Thu/Fri but with this policy, the earliest they would even be tested would be if my result comes back positive on Wednesday. By then their contacts from last week will already be spreading...

Urgency and aggressive testing is the difference between winning and losing this war. Japan is asleep at the wheel. If winter and economic opening brings a spike in cases, this attitude to testing will be completely ineffective and a big shutdown will be required.

#COVID19

Disney and cultural genocide in Xinjiang

Disney has reached a new low in scumminess. I wouldn't expect them to make a live-action Mulan without filming in China but there was really no need to film in an area that was then and is now conducting cultural genocide and then thank them in the credits. This seems to be Disney demonstrating its willingness to basically do anything to be friends with China. There are a bunch of articles reporting this but this one goes into a fair bit of details and interviews some observers. If you must see Mulan, please find a way to do it without giving money to Disney...

COVID 19 and aerosols FAQ

The idea that aerosol transmission of COVID is very important is gaining traction. Some scientists are even speculating that it’s the most important vector, especially for super-spreader events. The lady who infected 27 people in a Starbucks in Seoul by just sitting under the aircon for 2 hours seems to be a very clear case of massive aerosol spread. WHO and CDC are not on board yet, but they seem to be generally slow to adopt new ideas. Japan has been onboard from way back with the 3Cs but didn’t really do anything to convince the world about it.

The conventional wisdom on aerosol transmission seems to stem from an old book on the transmission of diseases but there is no basis for believing that only a highly infectious disease like measles can spread this way.

This FAQ has been put together by a bunch of researchers and provides advice and good justifications for all the advice. In particular the sections on general protection and on masks are well worth reading. They justify everything with references, they are clear on what’s still unknown and they debunk a bunch of misconceptions. Key points are summarized below.

They have also made a truly awful acronym to help you remember. It’s Avoid Crowding, Indoors, low Ventilation, Close proximity, long Duration, Unmasked, Talking/singing/Yelling/breathing hard (“A CIViC DUTY”).

Just remember that an infected person, breathing in an unventilated room can fill that room with floating virus, possibly for hours after they leave. And there are a bunch of fairly obvious factors that make you more or less likely to get infected:

• how many sources there are (more people => more chances of an infected person)
• filtering (their mask and your mask)
• how close you are to the source
• how much aerosol the source is producing (from normal breathing to screaming)
• ventilation (how often is the air replaced by clean air)
• how long you’re exposed

A tight fitting mask, even a cloth mask protects you and others (great news, if aerosols really are a big factor your mask really protects you now too, not just everyone else, maybe now even selfish pricks can wear a mask). You want multiple layers of cloth and don’t worry about “the virus is much smaller than the holes in your mask” that is not how aerosol filtering works. Your mask is not going to be perfect but it’s like sunburn, factor 50 is way better than factor 10 which is still better than nothing.

There’s lots more detail in the doc it’s worth reading those sections in full.

If you were being careful, a lot of the above is stuff you were doing anyway. However, people and places that take very visible precautions against droplets but do nothing for aerosols are potentially making things more dangerous by giving the impression of safety and encouraging people to expose themselves to more danger.