One for Karen…
I understand that the condensate can be formed because Helium nuclei are bosons, with integral spin. But Helium nuclei are made from protons and neutrons, which are in turn made from quarks, all of which have half-integral spin. How are they able to overlap, just because they are in Helium nuclei?
Or is there in fact a limit to how dense the condensate can become, before these effects are important?
It is too clear, and so it is hard to see.