From India to Spain, the brilliant civilization of Islam flourished. What was lost to Christendom at this time was not lost to civilization, but quite the contrary… To us it seems that West-European civilization is civilization; but this is a narrow view.
Bertrand Russell, History of Western Philosophy
- Spiral arm (Wikipedia)
Spiral arms are a defining feature of spiral galaxies. They manifest as spiral-shaped regions of enhanced brightness within the galactic disc. Typically, spiral galaxies exhibit two or more spiral arms. The collective configuration of these arms is referred to as the spiral pattern or spiral structure of the galaxy.