When in armchair-physicist speculation mode I’d always assumed that at some essentially limit density the speed of sound would tend towards that of the speed of

When in armchair-physicist speculation mode I’d always assumed that at some essentially limit density the speed of sound would tend towards that of the speed of light, and sort of conflate the two. The idea that the limit of the speed of sound is so ‘terrestrial’, so Newtonian, so within-our-domain kind of size (beyond personal experience but within the realm of extrapolation, if you will) absolutely fascinated me.