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You can get a new 7 seat mini van for around 35. You can get a new 15 passenger van for around 50. By the time you have that 15th kid it's like you're making money

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https://www.verywellfamily.com/how-much-does-it-cost-to-raise-5-or-more-kids-5075170

> Researchers found that families with one child spend 27% more on the only child. Families with three or more children spend 24% less on each child.

Anecdotally kids from larger families I knew growing up often had older children support parenting duties, such as covering for an hour or two between school and work, or driving siblings to school once they got their license.

>Cars are a big one.

Yeah, I was thinking about that after I posted. Some go to a minivan, but when you deal with 6+ kids there is a point where you need a second vehicle, but some smaller families already have a 2nd vehicle, one for each working partner. I accept it's a complicated exception but wasn't sure how to quantify it.

Sometimes there will be cases where an extra kid doesn't cost more, until you hit capacity and have to spend twice as much (or thrice if you have an unusually big family).

I would take source to be the largest point of entry, and point from where the radon gas diffuses out into say the basement. However, I see your point in that it's not like a heat source or lead atom generator that constantly acts like a "lead source"

From what I can see, the gas gets in via cracks/voids in the foundation so in theory you could take those points of entry as "sources"

Lead-214 has a half life of 27 minutes, you're thinking of Lead-210.

Radon-222 -> Po-218 + Alpha (3.8 days)

Po-218 -> Pb-214 + Alpha (3.1 minutes)

Pb-214 -> Bi-214 + e^(-) (27 minutes)

Bi-214 -> Po-214 + e^(-) (19.7 minutes)

Po-218, Pb-214 and Bi-214 are the most important radon daughters, they are responsible for most of the (indirect) radiation dose from Radon-222.

Pb-214 and Bi-214 are also ions, singly ionized.

Also, the Po-214 daughter travelling at 13 million miles per hour, recoil from kicking out a Alpha particle at 8% the speed of light.

He was correct. Lead oxide isn't formed.

There's several factors that need to be considered. The fact that the Lead-214 daughter is singly ionized so reactions with oxygen aren't favoured, that air is humid and is often contaminated with VOCs and SO2, especially indoor air, and the fact that these reactions take place within an ionization trail generated by the Alpha particle, that generates hydroxy radicals from atmospheric humidity and NO2 (the radon daughter atoms recoil at 10-13 million mph btw).

Instead, Lead-214 will most often form tiny clusters surrounded by 5 to 8 water molecules and likely often a few molecules of VOCs. They measured the size of the clusters, they average 1.2 - 2 nm in diameter. Po-218 is a little different, it forms larger 15 nm clusters additionally with SO2 (once air contains a few ppm of SO2) and as, well as much smaller clusters of PoOx 0.5 - 1 nm in diameter (the proportion of these clusters depends on what's in the air).

Castleman Jr, A.W., 1991. Consideration of the chemistry of radon progeny. Environmental science & technology, 25(4), pp.730-735.

Hopke, P., 1996. The initial atmospheric behavior of radon decay products. Journal of Radioanalytical and Nuclear Chemistry, 203(2), pp.353-375.

One important consideration is the fact that Lead-214 and Bismuth-214 are electrically charged, singly ionized ions. The other factor that needs to be taken into account is the fact that these reactions occur within an ionization trail that contains hydroxyl radicals and NO2 (the Alpha particles are ejected at 7-8% the speed of light, and the daughter atoms recoil at 10 to 13 million mph). And the final factor that make all this more complex that single atoms floating in nitrogen and oxygen is the fact that air isn't pure, but is often contaminated with volatile organic compounds, particularly indoor air, and SO2.

As a result Lead and bismuth oxide isn't formed. They form clusters of 5 to 8 water molecules and often a few molecules of VOCs. They were measured experimentally, and are 1.2 - 2 nanometers in diameter.

Po-218 is a little different, it can form larger clusters about 15 nm that additionally contain SO2 (if air contains a few ppm of SO2, common in urban and inner city environments), and water molecules. It can also form much smaller clusters of PoOx, 0.5 - 1 nm.

I think I've summarize what I read correctly.

Ref.:

Castleman Jr, A.W., 1991. Consideration of the chemistry of radon progeny. Environmental science & technology, 25(4), pp.730-735.

Hopke, P., 1996. The initial atmospheric behavior of radon decay products. Journal of Radioanalytical and Nuclear Chemistry, 203(2), pp.353-375.

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The “design flaws” are:

Reactor design with active boiling and positive void coefficient, such that your power profile is essentially inverse to your normal control rod position. Additionally you are severely impacted by things like trips of a reactor coolant pump.

No mechanical limits on location of the graphite followers (not just control system limits, but a physical hard stop)

The graphite followers having to move past the fuel is the result of the two above plus the operators making some very dumb decisions.

If those graphite followers were never removed as much as they were, if they essentially stayed in the lower portion of the core, they would have been fine. But when you pull them out far enough, then during the reactor trip they will initially add reactivity.

I thought the same. Would 'costs go up logarithmically' be the right term?

Those would be linear or probably slightly less than linear costs though.

More people in a house eat more food, but you can buy in bulk for savings so cost per person could go down.

Utilities would scale more or less linearly given the area of the house stays the same. Water is iffy it might go up with more people having showers but might go down by doing larger washing loads at a time.

Transportation is interesting though as it's theorized cars having 5 seats caused a tiny effect on families only having 2 children because there's not enough room for 3 baby seats in the back of most cars.

> What things with 4 kids cost more than twice as much as 2 kids?

Cars are a big one. It's not a linear increase, it's a massive jump you're forced to make at a certain point. Particularly for booster seats.

I agree with you otherwise, but there are a few things which do jump up.

Your regular four or 5 seater was already going to be bought, likely even with 0 kids, so the cost is effectively 0 for the first two-three kids (depending on age separation and need for boosters). Then it suddenly jumps up in cost.

I was thinking the same thing. Maybe it's exponentially where the exponent is between 0 and 1.

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all animal eyes use photopigments that are descended from a common ancestor - whether or not that thing (a basal eumetazoan, which would have looked more like a sponge larva than any animal you've ever seen) had eyes, I think probably not. but it seems that, having evolved these supremely useful molecules, evolution figured out pretty quickly the best way to make use of them ("build an eye").

(if there is something recent suggesting a common ancestor to all eyes, i'd really like to see it!)

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Those things would increase linearly, at worst. Of course three kids cost more than two kids, just not 50% more. I'd posit that for every kid x, the added cost is less than for kid x-1.

Well food would cost more. And if you add other factors - childcare, transportation costs, certain bills - with more people in the household, there's gonna be more utilities used. I was thinking of those factors. But you're right if there's a difference in the grand scheme of things, it likely wouldn't be much. Though in the more easy to see aspects, again food, will go up (also buying diapers while buying school supplies) would give the impression that things are more expensive. Which is a stressor even if not as big of a difference

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> with every additional child the costs go up exponentially

Wouldn't the additional cost per child go down? Generally insurance for a family is the same rate regardless of size. With multiple kids, some of the stuff they can share. Hand me downs, bedrooms, etc.

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What things with 4 kids cost more than twice as much as 2 kids?

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