Most complicated biological structures are alive. They are supplied with blood, monitored by nerves, maintained continuously and repaired when damaged.
A feather is none of those things. Once grown, it…
The single idea that makes all of this make sense is that cold is not a thing being added but heat being taken away and put somewhere else. Everything below…
There is a category of human variation that is essentially invisible, because it concerns something nobody can observe in anybody else and nobody has reason to compare.
Ask two people…
There is an assumption that things used routinely are understood, and it does not hold in general.
A great many effective interventions were established empirically — somebody noticed that something…
Everything below comes from one thing: the axis the Earth spins on is not perpendicular to the plane it orbits in. Every seasonal phenomenon anywhere is a consequence of that…
The distinction that organises the whole subject is between comparing and measuring. A balance compares; a scale measures a force. Almost every difference between weighing devices follows from which one…