All of alahonua's Comments + Replies

The Holy Algorithm

Actually, the Easter 2021 date is in May for some Eastern communities: see

This is both messed up and not surprising.
Base rate of RCT from developing countries finding unexpected effects

The rapid availability of third world originated studies to internet searches by those living elsewhere, which has happened because of internet publishing and especially in the last three years because of openly searchable preprint sites such as medrxiv, is a new enough thing in science that I doubt there has been enough time to get a valid such likely future failure rate, especially if you are including preprints.

To get an approximate base rate you would need to check the years prior to open internet medical paper publishing. At minimum you would need to ... (read more)

Thanks for the answer, and I understand where you are coming from. But concluding that "we need to do more studies" is not useful in this case, when most of the future damage of the pandemic will happen in the next few months, and publishing new studies takes close to a year.
A Simplified Version of Perspective Solution to the Sleeping Beauty Problem

From a completely subjective view, there can be no single answer as to what day of the week it is. It is whatever weekday  I decide it is. Who could gainsay it?

As soon as we allow an objective view of what day of the week it is, we implicitly allow an over-ride of the subjective viewpoint by the objective one, and the 1/3 probability becomes the better choice.

An argument for personal identity transfer.

One advantage to a thought experiment is that it can be scaled without cost. Instead of your  sorites series, let us posit a huge number of conscious humans. We alter each human to correspond to a single step in your gradual change over time, so that we wind up performing in parallel what you posit as a series of steps. Line our subjects in "stage of alteration" order.

Now the conclusion of your series of steps corresponds to the state of the last subject in our lineup. Is this subject's consciousness the same as at start? If we assume yes, then we hav... (read more)

An argument for personal identity transfer.

Almost all gradual-brain-to-device replacement arguments are indeed sorites arguments. You assume:

Plucking one or three hairs from a beard that has 10000 hairs beard is too small an action to change a beard visibly

Plucking 2 hairs from a beard with 9998 hairs is too small a change to see (true)

Plucking 2 hairs from a beard with 9996 hairs is too small a change to see (true)


plucking 2 hairs 4000 times from a beard is too small a change to see (false)

If plucking hairs changes my beard then there will be a point at which it is noticeable before it is completely gone. My beard does not go from existing to not existing in a single pluck. My consciousness does not go from existing to not existing in a single neuron pluck. My identity does not radically change in a single pluck. There is a continuum of small changes that lead to large changes. There will come a point at which the changes accumulate that can be noticed. Note that I'm not referring to gradual changes through time, but a single procedure occurring once that replaces N neurons in one go. Assume that the procedure does produce a significant change, significant meaning noticeable but not crippling, to consciousness at some number of replacements U. There is a number of replacements 0 < N <= U such that N-1 replacements is not noticeable by the subject. Noticing is a yes or no binary matter, the subject can be asked to say yes or no to whether a change is noticed. The crucial part of the argument is that one cannot in any way notice any difference regardless of how many neurons are altered during the procedure because the specified procedure preserves behavior. Conscious awareness corresponds with behavior. If behavior cannot change when the procedure alters a third of the brain, then consciousness cannot noticeably change. If consciousness is noticeably changed from an internal perspective then a difference in behavior can be produced.
Examples of Measures

Read this online classic paper about geometric measure theory, because it's really entertaining:

1Maxwell Peterson2y
Nice recommendation - learned multiple things from it
Sleeping Julia: Empirical support for thirder argument in the Sleeping Beauty Problem

I think that OP is confusing expected value with probability.

The  expected value formula is the probability of an event multiplied by the amount of times the event happens: (P(x) * n).

This explains the P(B) = 1.5 the OP put above-- he means the expectation is 1.5, because P(waking with any one coin flip result) = 1/2 and the times it occurs is 3.

So the halfers believe the expectation is 1/2 for waking with heads and 1/2 for waking with tails.

The thirders have the expected values right:  1 for waking with heads, 2 for waking with tails.

Born as the seventh month dies ...

This is correct, if you are excluding the case where both are boys both born on Tuesday. Otherwise you would not subtract p(A and B). But, you did not say only one, you said _at least_ one.

1Rudi C2y
It’s not about excluding that case. It’s about not counting it twice. Search for the inclusion-exclusion principle to see the reasoning behind it.
Born as the seventh month dies ...

I don't think you have the dependencies quite right, because you can actually use more of the information than you do above to restrict the population from which you draw.

The real underlying population you should draw on seems to to be the population of fathers with exactly two children, of which one might be a boy born on Tuesday.

p(a two boy family given one brother was born on Tuesday) = (p(one brother born on Tuesday in a in two-boy family)) (p(two boys in 2 person families)) / p(out of all two person families, having one be a boy born on Tuesday)

which is if we say Tuesday birth is 1/7 and boy is 1/2,

(2/7) (1/4) / (2/14) = 1/2 so the Tuesday datum drops out.

1Rudi C2y
You're not stating what probability rules (theorems/axioms) you are using (you're probably going by intuition), and you have made mistakes. p(one brother born on Tuesday in a in two-boy family) is not 2/7; It's 1/7 + 1/7 - (1/7)(1/7) because you're counting the two children both being born on Tuesday twice. The same mistake has been made in calculating p(out of all two person families, having one be a boy born on Tuesday); The correct answer is (1/2)(1/7) + (1/2)(1/7) - (1/2)(1/7)(1/2)(1/7). The rule you're not following is: P(A or B) = P(A) + P(B) - P(A and B) When these mistakes are corrected, the correct answer comes out: ((1/7 + 1/7 - (1/7)*(1/7))*1/4)/((1/2)*(1/7) + (1/2)*(1/7) - (1/2)*(1/7)*(1/2)*(1/7)) = 13/27 =~ 0.4814
Do any mammal species exhibit an immune response in some of the herd in response to the infection in other herd members?

It is not a crazy question at all. In fact it has a variety of answers: I will summarize with a "no," a "yes," and a "no."

1. No, exposure of others to Covid-19 may cause them to become specifically immune to that virus, but it will not cause us to also become specfically immune unless we are similarly exposed to virus components themselves, not just the persons involved.

2. Yes, the fact that people near us are in distress because they are sick will probably cause us, as we too are distressed by the situation, to secrete str... (read more)

Help me with bayesian thinking re:coronavirus?

Yes, true. The exact numbers are very uncertain, but the qualitative point remains that someone who feels fever many days per winter has less chance of a similar day with fever being from covid than someone with a fever today who has had no fever for over a year.

Help me with bayesian thinking re:coronavirus?

To answer properly you need to know the prevalence of fever of any kind. In particular, you might use the number of days with fever per year you had last year / 365, for example. If you literally never get a fever for years, I'd worry more then if you did.

P(19coro | fever) = P(fever| 19coro, about 0.5??) * P(19coro, perhaps 0.001??) / P(fever)

Just for clarification P(fever) must include fever which comes from 19coro. P(fever)=P(fever|othercauses)+P(fever|19coro)
Is it worthwhile to save the cord blood and tissue?

1. Not very valuable. Handling and storage costs far outweigh acquisition costs.

2. Unmatched, easy; well matched, somewhat difficult.

3. Generally it depends on the specific inherited immune characteristics of mother and child, similar to these factors in kidney donation.

4. For decades, yes, for a lifetime no.

5/6 No and sort of yes.

If you are going to donate cord blood for others, as a humanitarian thing, check with your OB/GYN about whether they know who would need to be there to ship the donation.

If you are going to save it for family use, I would do so o... (read more)

How to avoid dying in a car crash

I know no one is likely to do this, but consider the safeguards taken by auto racing drivers. They are required to wear a helmet. For high speed driving helmets on all in the car would cut the death rate. That said, I doubt anyone will do this, as the inconvenience is great for a small payoff.

We're required to wear helmets, nomex suits, gloves, socks and shoes (lots of fun in 90F+ degree weather), head and neck restraint devices and 5 or 6 point harnesses. However keep in mind race cars do not have airbags, while its becoming more and more common for passenger cars to have airbags galore. With airbags, the benefits of a helmet are much reduced.
I don't suppose you know of any research on what effect helmets have on rates of death and injury at speeds people are likely to drive at for ordinary transportation?