But let me go back to these sines, cosines and logarithms.

但让我们再来说说正弦、余弦和对数函数。

That negative 5, is your base 10 logarithm.

这到底为什么会发生呢？

And a little bit about pOH, which can be calculated with logarithms, also with subtraction.

它们通常也有很低的pH值。

You learned about logarithms and how you can use them to calculate the pH of a substance.

因为它们使氢离子浓度大幅提升。

The new formula relies on the mathematical concept known as logarithms.

新公式依赖于称为对数的数学概念。

And not just any logarithms, but those known as " natural" ones.

不仅是任何对数， 还有那些被称为“自然” 的对数。

So, yeah, logarithms can seem a little bit scary at first, but the ones that we're using here are super easy.

我们通常把水看做一种完美的中性物质。

Though he had an interest in logarithm and logistics, he wanted to be a logician.

虽然他对对数和后勤学感兴地，他想成为一名逻辑学家。

The horizontal line is time before present, and the vertical line as the logarithm of sizes of settlements.

横线是现在之前的时间，纵线是聚落规模的对数。

But one thing you need to remember about the pH scale, because pH is calculated from a negative logarithm, it turns everything backward.

而且由于它是一个十分特殊的反应，因此它有一个独特的名字——水的电离常数，也就是Kw。