&gt; <i>gravity is so admittedly poorly understood</i><p>Gravity as a force&#x2F;phenomena in space on its own is actually very well understood. In fact it&#x27;s possibly one of the most well understood theories we have in physics because of general relativity. However, at a particle scale we lack the understanding of how gravity would work.<p>Dark matter is the collective name for whatever &quot;stuff&quot; exists in the universe that we predict it should have, however because it is noninteractive in any way other than exerting a gravitational pull (it accounts for a lot of astrophysical observations that otherwise are bewildering given what we <i>see</i> in the universe). We know it should exist, we don&#x27;t know what it is and can barely understand its current properties. So indeed, it is quite possible that it might be Aether-ish if we end up finding something else that explains our current observations or a drastic overhaul of how gravity works at large scales (the latter being very unlikely because of how well GR has stood up to experimentation so far).