> somewhere around a hundred atoms per cubic meter.
Wikipedia says that intergalactic space contains less than one hydrogen atom per cubic meter; and that most of the baryonic matter in intergalactic space consists of hydrogen and helium atoms. If I've understood it correctly...
Well, I don't think the discussion was restricted to interstellar space; for example there's been quite a bit of chat about how long it would take, at 1G (on the astronaut's watch) to reach the edge of the (known) universe.
Wikipedia says that intergalactic space contains less than one hydrogen atom per cubic meter; and that most of the baryonic matter in intergalactic space consists of hydrogen and helium atoms. If I've understood it correctly...
https://en.wikipedia.org/wiki/Outer_space