There is a common assumption about concealment that is intuitive and mostly wrong.
The assumption is that hiding means matching — that the way to be invisible is to be…
There is a useful principle about signals that applies well beyond sound, and whistles are the clearest everyday demonstration of it.
The principle is that being heard is a matter…
There is a common assumption that different teas come from different plants, in the way that apples and pears come from different trees.
They do not. The overwhelming majority of…
There is a common way of describing chimneys that gets the direction of the mechanism backwards and consequently makes every practical problem inexplicable.
The description is that smoke rises and…
Two processes determine the result: what roasting creates, and how much of it the water takes out. Almost every difference between one cup and another is one of those two.…
Light leaves every point of a subject in all directions. A lens collects some of that and reconverges it, and the entire craft is built on the properties and failures…