archive.log
Archive
Indexed by principle and error type, not by chapter.
5 editorials
Why a Sidereal Day Is Shorter Than a Mean Solar Day
relative-angular-motion
Earth rotates once relative to the stars in about 23 hours 56 minutes, yet our clocks use a 24-hour mean solar day. Earth's orbital motion accounts for the difference.
Written by Renee
Why the Rayleigh–Jeans Law Predicts an Ultraviolet Catastrophe
quantum-suppression-of-high-frequency-radiation
A formula that works at long wavelengths predicts unlimited radiation at short wavelengths, but real blackbody spectra do not behave that way.
Written by Renee
Why eccentric orbits give uneven transits
keplers-second-law-and-transit-duration
A planet crosses its star's disc faster at some points in its orbit than at others, and eccentricity sets the difference.
Written by Renee
Binary search on the answer: why the predicate must be monotonic
monotonic-predicate-search
Binary search doesn't need a sorted array. It needs a predicate that flips exactly once.
Written by Renee
Projectile range symmetry: why 30° and 60° land in the same place
trigonometric-symmetry-in-kinematics
Two launch angles, one range. The landing point is the same and the flight is not.
Written by Renee