Intelligent life first appeared on earth some 10 or 20 billion years after the universe began a complex sequence of events ranging from nuclear reactions under hot, dense conditions, through galaxy formation, further nuclear reactions in stars, chemical processes, and biological evolution. The individual events and their sequencing appear both natural and likely, given the microscopic physics we observe in the laboratory and the large-scale parameters of the universe. But they are also rather sensitive to these being as they are and not otherwise. This suggests the existence of a deeper level of underlying physics that we have not yet fully understood.
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