The reason why galaxy clusters can teach us about dark matter, the reason why galaxy clusters can teach us about the physics of the very small, is precisely because they are so very big.
Kelompok-kelompok galaksi boleh mengajar kita tentang jirim gelap, kelompok-kelompok galaksi boleh mengajar kita tentang  aspek sangat kecil, semuanya kerana ia sangat besar.