(June 3, 2014 at 2:23 pm)Chuck Wrote:(June 3, 2014 at 2:08 pm)max-greece Wrote: The reason it was thought that rocky planets couldn't exist so early in the universe isn't merely the availability of metals (heavier elements) but profundity. A lot of massive stars have to collapse for there to be a chance of sufficient amounts to be caught under gravitation to form a planet. Remember that when a star explodes it does so in all directions and at high speed. What you need is overlays of exploded metals from multiple stars to gather in a sufficiently small area to be caught up and combined into a planet.
That, was considered unlikely until now. Obviously somewhere along the line we got something wrong. That's why it is a surprise.
But I believe the low metalicity of early universe hamper the formation of all but very large stars, so the proportion of massive stars amongst population III is much larger than in our current universe, and very large porportions of population III stars would have popped off as supernovas distributing elements up to iron into surrounding space.
This suggests the at least in the primordial star forming regions of early universe supernovas would occur at much higher frequency than now, and heavy elements would have been manufactured and liberated at mucg higher rate than would be the general case now.
I'm at the disadvantage here that the evidence is now there that you might be right. I am just trying to explain why it was thought otherwise.
Remember that the low metalicity would also tend to lead to planets forming that were gas giants which takes us full circle as to why we were not expecting the formation of rocky planets.
That's all I have on this. Maybe it shouldn't have been a surprise - but it was, and not just to me. You'd have to ask a physicist for more.
Kuusi palaa, ja on viimeinen kerta kun annan vaimoni laittaa jouluvalot!
