3 ms·
There is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (m
by keithnoizu 12y ago
There is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (meaning our planet was seeded at some point with some primitive life forms that than continued on their evolutionary tracks towards this point in time).
So you have many planets starting to get to the point where space exploration on a wide scale is feasible. Maybe a few are a hundred thousand and some change years ahead or behind us but the likelihood is low that many are significantly well established, or established long enough and close enough for us to detect.
- DavidSJ 12y agoThere is actually a pretty good explanation for it in my opinion, that it takes about this long since the big bang for life forms of our complexity to exist. (meaning our planet was seeded at some point with some primitive life forms that than continued on their evolutionary tracks towards this point in time). Interstellar seeding is not required to believe that complex life becomes possible at approximately the same time throughout the universe. Other possible reasons: - Concentration of heavy elements has increased with successive star generations. - Galactic cosmic ray bursts (which can sterilize all complex life within thousands of light years) become less common as a galaxy ages.
- rjsw 12y agoFrequency of big meteorite impacts probably becomes less over time too.
- marcosdumay 12y agoThat's an intra solar-system variable, it does not apply to a galaxy.