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First Life in the Universe

Here, we ask a simple question, i.e. "at what cosmic time, at the earliest, did life first appear in the universe?" Given what we know about the universe today, there may be some partial answers to this question, but much will still have to be left to speculation. If life in general requires stars as its primary energy source and uses elemental building blocks heavier than those initially produced in a Big Bang scenario, first life could have appeared, when the universe was considerably less than 0.1 billion years old. At that time, heavy element producing hypernovae exploded at corresponding redshifts.} $z$\,\gapprox\,45, significantly higher than commonly assumed ($z \approx 6$). The recent discovery of a galaxy at $z > 9$ could provide supporting evidence for the hypothesis of a very much shorter time scale than what is widely believed.