m. c. de marco: To invent new life and new civilizations...

BDO of Talk Like a Pirate Day: Virga

Today is International Talk Like A Pirate Day, so I’ve picked a pirate-themed BDO for the Big Dumb Object of the day: Virrrrrga—I mean, Virga—is a carbon-nanotube sphere 5000 miles in diameter, enclosing 65 billion cubic miles of volume. It’s is a weightless environment filled with a breathable atmosphere circling a real sun at some distance, in which smaller habitats are rotated for gravity and artificial suns provide light and heat. It’s the steampunk setting for Karl Schroeder’s eponymous airship series beginning with Sun of Suns and including Pirate Sun:

The science behind Virga is explained on his website. Schroeder explains why he gave Virga a relatively modest size, though a balloon environment like his with an Earth-like atmosphere could be almost 22,000 miles across (5.5 trillion cubic miles of space), while a lighter atmosphere permits a sphere about 250,000 miles across (8 quadrillion cubic miles). Plenty of rrroom for pirates!