The single variable that explains most of what you see is how thick the lava was. Runny lava spreads out and builds gentle slopes; thick lava traps gas, moves barely…
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 organising fact is that a plant has several parts, and if you consistently select for one of them getting bigger, you eventually get a vegetable that is mostly that…
The single most useful habit is to look at how the trees meet the ground. Multiple stems from one base, a swollen top on a short trunk, or a single…
The useful question about any symmetrical thing is not why somebody made it that way but what process would produce that arrangement without anybody deciding. Here are sixteen answers.
1.…
Everybody who has been somewhere completely dark reports the same surprise: the sky is bright.
Not bright like daylight, but visibly not black. There is enough light to see the…