Bioceramic Mind

The bioceramic mind is a replacement for a naturally evolved brain. It allows an individual to live for millions or even billions of years, as long as the mind is not destroyed. It is very sturdy, but can be destroyed with a plasma torch. It can also be destroyed in a disaster such as a comet impact or being submerged in magma.

Humans gained this technology and others when they intercepted an alien signal in the 21st century. The technology is very old and widespread - in Precious Mental it's revealed that over 20 million species in the Milky Way galaxy use bioceramic minds, and nearly all use the same basic design.

The majority of humans on board the Great Ship have bioceramic brains, but it has thousands of communities of mortal humans. Many of these mortals consider the immortals to be machines masquerading as humans.