Definition: Voxel

Voxel

A voxel represents a value on a regular grid in three-dimensional space.

 

Basically, the 3D equivalent of the 2D pixel.

 

From this fantastic TEDRadio Hour podcast on the brain!

Definition: Accretion Disk

Accretion Disk

The disk of stuff you see circling black holes in artist renderings like the one in the picture.

More formally..

An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction causes orbiting material in the disk to spiral inward towards the central body.

 

Hear about accretion disks and a LOT more interesting and mind blowing stuff about astrophysics in the TEDRadio Hour podcast below!