Time to update my satellite pollution talk.
There are ~500 more Starlink satellites today than when I gave this talk in July.
4,924 Starlinks in orbit now (56% of the total 8,728 active satellites in orbit).
Just your periodic reminder that one private company owned by one pretty awful dude effectively controls outer space now.
An owl gliding through a cloud of helium-filled soap bubbles reveals wingtip and tail vortices.
Video credit: Usherwood et al.
Source: https://journals.biologists.com/jeb/article/223/3/jeb214809/223686/High-aerodynamic-lift-from-the-tail-reduces-drag
Summary: Aerodynamic lift from gliding hawk and owl tails, revealed by tracking helium bubbles, is inconsistent with passive stability or minimizing induced drag, but indicates a role in reducing viscous drag.
Prof. Sam Lawler
Wonder of Science