english: And, as we've learned in the last few years, galaxies are held together by the gravitational pull of so-called dark matter: particles in huge swarms, far smaller even than atomic nuclei.
non_english: Kako saznajemo, galaksije se drže na okupu gravitacionom silom takozvane tamne materije: ogromni rojevi čestica, mnogo manji čak i od atomskih jezgara.