Complex life in the universe may be much rarer than previously thought


At least, according to a couple of astrophysicists: Complex life may be possible in only 10% of all galaxies | Science/AAAS | News.

The universe may be a lonelier place than previously thought. Of the estimated 100 billion galaxies in the observable universe, only one in 10 can support complex life like that on Earth, a pair of astrophysicists argues. Everywhere else, stellar explosions known as gamma ray bursts would regularly wipe out any life forms more elaborate than microbes. The detonations also kept the universe lifeless for billions of years after the big bang, the researchers say.

…The sheer density of stars in the middle of the galaxy ensures that planets within about 6500 light-years of the galactic center have a greater than 95% chance of having suffered a lethal gamma ray blast in the last billion years, they find. Generally, they conclude, life is possible only in…

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Crystal Spheres: Part 1 – What is a Crystal Sphere?

Reblogged from Wildspace: the Spelljammer Fanzine

Wildspace: The Spelljammer Fanzine

Crystal spheres are one of the unusual features of Spelljammer that set the game apart from other fantasy space roleplaying games. Some people really like them – other people dislike them and tweak the game to remove them. I would like to tell you why I think crystal spheres are a really useful part of the SJ Universe, but first, here is a reprint of the crystal sphere article I wrote for Spelljammer Wiki.

A crystal sphere, also known as a crystal shell, is an object of great size that surrounds an entire planetary system and forms a boundary that separates wildspace from the phlogiston.

The size of crystal spheres is related to the size of the planetary system within them. As the name ‘crystal sphere’ implies, the objects are spherical.

Although they are solid, crystal spheres have no gravity and no atmosphere. The material crystal spheres…

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