December 3, 2022

Both vortices and vortexes are correct plurals of vortex, meaning “whirlpool, eddying mass.” The original plural noun form is vortices (for Latin purists).

The plural of virus is viruses. Virus forewent its Latin plural noun form, or simply never had one.

The plural of nucleus is nuclei (Latin) or nucleuses.

Both nebulae and nebulas are accepted plurals for nebula.