科學上的飽和：裝到不能再裝
這一支是核心畫面最原本的地方：真的有一個可以觀察、可以記錄的臨界點。
noun · C1
In science, the state a liquid mixture reaches when it has taken in as much of a solid substance as it can, so that any more of that solid will not dissolve.
飽和點（化學）
核心畫面
You can picture a glass of water with sugar going in, spoon by spoon. Every vanishes, until one does not. From that moment the glass is holding all it can, and anything more just sits there, wasted. Saturation point names that exact moment of no more room, and the word keeps working the same way whether what is filling up is a liquid, the air, a street, or a person.
可以想成一杯水，糖一匙一匙加進去。每一匙都化掉，直到有一匙沒化。從那一刻起，這杯水已經裝到極限，再多加的只會沉在底下…更多收起
可以想成一杯水，糖一匙一匙加進去。每一匙都化掉，直到有一匙沒化。從那一刻起，這杯水已經裝到極限，再多加的只會沉在底下，白白浪費。saturation point 指的就是那個「再也裝不下」的臨界點。不管在裝東西的是液體、空氣、一條街，還是一個人的腦袋，這個字的運作方式都一樣。Two branches
比喻的飽和：地方、市場和人也會滿
英文把杯子的畫面整個借出去用。裝不下的東西從糖換成遊客、店家、資訊，但「再多就沒有用了」這個重點沒有變。這是概念上的借用，不是說這個意思比較晚才出現。
noun · C1
The point at which no more people, things, or information can be added or taken in, because there is already as much as the place, the market, or the person can hold.
飽和點／到極限