Blood pressure, air sacs and the engineering problems of holding a neck above the canopy.

Flowering plants appear late, spread fast, and rewrite every food web they touch.

Redshift, Hubble's law, and why an expanding universe has no centre to point at.

Why the plates were probably not armour, and what the tail spikes did to an allosaur pelvis.

Araucaria, monkey puzzle and the southern forests that survived what the giants could not.

Galaxies rotate too fast for the matter we can see. Something invisible is holding them together.