mwacksen

COVID/Delta advice I'm currently giving to friends

though Delta is a bigger risk than Alpha, ignoring effects of vaccination

I keep seeing claims like this get thrown around, but I feel like the evidence isn't really there. Could you comment on why you think this?

Quadratic, not logarithmic

Sorry for the late reply. I'm assuming you need to be "infected" in order to infect someone else (define "infected" so that this is true). Since being infected is a neccessary precondition to infecting someone else,

P(you infect someone else) <= P(you are infected),

and it's clear you can replace "<=" by "<".

This is basic probaility theory, I can't follow your notation but suspect that you are using some different definition of "infected" and/or confusing probabilities with expected values..

Quadratic, not logarithmic

Sorry for the (very) late reply, but I do not understand this comment and suspect maybe my point didn't come accross clearly, cf. also my other reply to the comment below this one.

Quadratic, not logarithmic

Apologies for the really late reply, but I don't think "marginal risk" in this context is well-defined. The marginal risk to yourself grows linearly in the number of people to first order. You could feel responsible for the marginal risk to all the other party goers, but they are people with their own agency, you aren't (in my opinion) responsible for managing their risk.

Quadratic, not logarithmic

On the other hand, the other problem is that even if the person is accepting the risk for themselves, I'm not sure they're processing the risk that somebody else gets seriously ill or dies.

Well maybe, but are you thinking of the fact that (trivially) P(you infect someone else) < P(you are infected)?

Quadratic, not logarithmic

Say you meet in a group of people that all care about each other. Then, by your reasoning, each of the people is responsible for risk, so in fact (by double counting once more as in the original post), the total risk is . If however, we share the responsibility equally each person is responsible for risk which is intuitive. So this quadratic growth assumption is a bit questionable, I'd like to see it done more formally because my intuition says it is not complete nonsense, but it's obviously not the whole truth.

I feel like this is almost too obvious to state, but question is really not about the marginal risk, but about the marginal benefit. Meeting 0 people probably is really bad your mental health in comparison to meeting 2. Meeting 98 people is probably not much worse for your mental health compared to meeting 100. Meeting 2 people might be more than twice as good as meeting one. But since we don't just care about ourselves, we should also think about the other person's benefit. So even if you are already meeting 98 people but the 99th meets nobody else the benefit you provide to that person may (depending on your age, preconditions, etc...) be worth more than the extra bit of risk.

Multiple Worlds, One Universal Wave Function

Then I have misunderstood Everett's proof of the Born rule. Because the tensor product structure seems absolutely crucial for this, as you just can't get mixed states without a tensor product structure.

Multiple Worlds, One Universal Wave Function

Well yeah sure. But continuity is a much easier pill to swallow than "continuity only when you aren't looking".

Multiple Worlds, One Universal Wave Function

We don't lose unitarity just by choosing a different basis to represent the mixed states in the tensor-product space.

I spent some time in Germany recently, and this is (or at least "was", when I was there) wrong. The tests themselves are considered accurate enough, but the bureacracies usually don't trust you to do it (or do it correctly). In some German states you can do a test

at the restaurantto be let in. You can buy a test, take it to a pharmacy, and let the pharmacy do it and then validate it. In some German states it is ok for some jobs to test yourself regularly. Back then I think employers also had to provide take-home tests for free (or if not required, strongly encouraged).