A common objection to dark matter as Bose-Einstein condensates is that the universe is violent. Supernovae explode. Galaxies collide. High-energy events should decohere dark matter BECs, making them visible. Yet dark matter remains dark. This paper resolves the objection. A laboratory BEC is microns across. A galactic BEC is light-years across. A BEC is not a collection of separate waves. It is a single quantum wavefunction. The critical velocity must be modified by the volume of the condensate. The force applied by any disturbance is distributed across the entire BEC volume. The effective critical velocity is the intrinsic critical velocity multiplied by the ratio of the disturbance volume to the total BEC volume. For a galactic BEC, this ratio is vanishingly small. The effective critical velocity is effectively infinite. No local disturbance can decohere a galactic BEC. The lab BEC is a droplet. The galactic BEC is an ocean. A rock disturbs a droplet. A rock does not disturb an ocean. The dark matter BECs are oceans. They have remained coherent for billions of years because nothing can disturb them enough.
Publication Date: 2026-06-20