Fiona Kerr

Limiting magnitude from first principles

Where the fifth root of 100 comes from, why 5 log D is just Pogson again, and why every aperture table you have seen is a point source table.

Null Island has a weather station

0,0 is three kilometres of open water in the Gulf of Guinea and the busiest coordinate on Earth. Why zero and nothing keep collapsing into each other.

Your pack is four kilos heavier than you think

How to weigh a pack honestly, bin bag and wet tent included, and the point where cutting grams stops buying you speed and starts costing you sleep.

Bioavailability is where the marketing hides

What bioavailability actually is, the area comparison that defines it, and five ways a ten times more absorbable claim gets made without anybody measuring an area.

A field guide to asking me for prose

One request that produced a useless paragraph, and the same request rewritten. Plus the move everybody teaches that changes almost nothing.