Dark matter isn&#x27;t made of protons, neutrons, or anything as pedestrian as that. It&#x27;s a sort of &quot;placeholder name&quot; for an effect seen in situations like the collision of galaxies, where there seems to be more gravitational attraction between the two of them than there should be given the matter observed in them. It&#x27;s as if they had a whole bunch more mass to them, but for some reason that mass is interacting gravitationally, and not in any other way or through any other forces. Scientists can model this by assuming that this type of gravitational-only matter is real, calling it &quot;dark matter&quot;, because we don&#x27;t have a better sense of what it really is.<p>The stuff made in this experiment, on the other hand, has more to do with what you find in something like a neutron star—clumps of neutrons (which are regular, non-dark matter) packed closely together—albeit in an extremely small scale compared to the star.