Hiho, long time since I've posted here. So I've been thinking about 1 or 2 things. Globular clusters are assumed to be the earliest structures formed in the universe because they are roughly the size of the Jeans length. But I'm thinking that if the universe was very nearly isotropic the areas with slightly different densities must be very large. When the gas in these areas condenses surely the gas clouds, and later on stellar nurseries would be similarly very large? Anyway, large quanities of gas = large stars, so surely the first early stars would be massive beasts? If globular clusters are the first structures that formed in our universe is it possible that they could originally have been inhabited not by small 1 solar mass stars we see nowadays but giant O/B main sequence stars? These stars would die farily soon after their creation so no evidence of their existence would remain except for a black hole. This would mean that our estimation of the masses of globular clusters is far below their true masses. Possibly entire clusters only contained massive stars and no low mass ones so that nowadays nothing is left except a cluster of black holes. What I'm trying to get at is that globular clusters are found, if I remember correctly, almost exclusively in galaxies and more importantly in the halo of galaxies. The average mass of a galaxy is something like 10 billion solar masses. Globular clusters contain about a million visible stars. If massive stars were a lot more common in the early universe these could have been outnumbered by a large factor by massive stars, bumping the mass of a globular cluster up to something like 100 to 1000 million solar masses. Add to this the possibility of completely 'dark' globular clusters containing only black holes and neutron stars then could this account for the invisible dark matter that appears to be in every galaxy's galactic halo? I know this argument is held together with string and 'what if's', I'd just like to know why this situation was unlikely/impossible to occur. Would the gravitational lensing from dark globular clusters be so large that we would have had to be blind not to notice it? Even if they resided on the edge of the dark matter halo? (which is iirc about 10 times the radius of the visible halo, at least for our galaxy) Cheers, Just some guy.