Comparison between a conventional galaxy (ESO 325-G004) enveloped in a halo of dark matter, occupying the heaviest plate on the weight scale, and the galaxy NGC 1277 (on the left), in which the study of the mass distribution reveals the absence of dark matter. Design: Gabriel Pérez Díaz (IAC). Image of NGC 1277: NASA, ESA, and M. Beasley (IAC). Image of ESO 325-G004: NASA, ESA, and The Hubble Heritage Team (STScI/AURA); J. Blakeslee (Washington State University)