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Not necessarily. First generation stars were, theoretically, enormous both due to low metallicity of the collapsed medium and a higher average concentration of

Not necessarily. First generation stars were, theoretically, enormous both due to low metallicity of the collapsed medium and a higher average concentration of said medium. These stars lifespans were extremely short, shorter that blue giants we see today. So novas due to the death of these stars happened fairly early in the lifespan of the universe (talking about few million years after the big bang). Therefore, life could have developed in a few tens to few hundreds of millions of years after the big bang. That's still true even if we assume that heavier elements are created mainly when neutron stars collide and not by super/hypernovas as we theorized before LIGO/Virgo observatories. Consequently, we likely are not a "progenitor" civilization in the universe if we only consider planets formation. We might not see anyone out there either because there's a great filter for intelligent life to emerge (so the bottleneck is in our past) or because few/no civilizations get to have an impact on their host stars (the filter is in our future) that would allow us to see them.

hnuser123456 4y ago
Basic life (single-celled?) requiring the elements above lead might have a chance at that time, but complex life like us wouldn't do so well if there were still supernovas going off left and right. There's a theory with decent evidence that at least one of the mass extinctions was caused by a supernova: https://www.space.com/supernova-caused-earth-mass-extinction-devonian.html https://www.space.com/supernova-caused-earth-mass-extinction... That being said, I wasn't aware of how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? Do you have any additional reading on that?
- marcyb5st 4y ago
  You are right about supernova hampering life evolution, but it's unclear how long the fireworks lasted. In my comment I argued that it is possible to have the conditions of life emerge much earlier than 13.5 billion years. Not that it necessarily happened. Regarding the second point have a look at https://www.ligo.org/science/Publication-GW170817Kilonova/index.php https://www.ligo.org/science/Publication-GW170817Kilonova/in... . That isn't my field of specialization, so I am not sure about recent publications. At the time though this was a big deal as kilonovas seem to be the primary source of heavy nuclei in the universe. That particular event crested between 1/100th to 1/1000th solar masses worth of heavy ( heavier than iron) nuclei. This is a greater rate than supernovas estimations.
- kubanczyk 4y ago
  > how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? It's not about the prevalence, but about the light curves observed during the event AT 2017gfo. They indicate significant heavy metal ejection but, what's interesting, also production. > mergers of neutron stars contribute to rapid neutron capture (r-process) nucleosynthesis These two articles cite the relevant papers: https://en.wikipedia.org/wiki/GW170817#Scientific_importance https://en.wikipedia.org/wiki/GW170817#Scientific_importance https://en.wikipedia.org/wiki/Nucleosynthesis#Neutron_star_collision https://en.wikipedia.org/wiki/Nucleosynthesis#Neutron_star_c...

hnuser123456 4y ago

Basic life (single-celled?) requiring the elements above lead might have a chance at that time, but complex life like us wouldn't do so well if there were still supernovas going off left and right. There's a theory with decent evidence that at least one of the mass extinctions was caused by a supernova: https://www.space.com/supernova-caused-earth-mass-extinction-devonian.html https://www.space.com/supernova-caused-earth-mass-extinction... That being said, I wasn't aware of how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? Do you have any additional reading on that?

marcyb5st 4y ago
You are right about supernova hampering life evolution, but it's unclear how long the fireworks lasted. In my comment I argued that it is possible to have the conditions of life emerge much earlier than 13.5 billion years. Not that it necessarily happened. Regarding the second point have a look at https://www.ligo.org/science/Publication-GW170817Kilonova/index.php https://www.ligo.org/science/Publication-GW170817Kilonova/in... . That isn't my field of specialization, so I am not sure about recent publications. At the time though this was a big deal as kilonovas seem to be the primary source of heavy nuclei in the universe. That particular event crested between 1/100th to 1/1000th solar masses worth of heavy ( heavier than iron) nuclei. This is a greater rate than supernovas estimations.
kubanczyk 4y ago
> how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? It's not about the prevalence, but about the light curves observed during the event AT 2017gfo. They indicate significant heavy metal ejection but, what's interesting, also production. > mergers of neutron stars contribute to rapid neutron capture (r-process) nucleosynthesis These two articles cite the relevant papers: https://en.wikipedia.org/wiki/GW170817#Scientific_importance https://en.wikipedia.org/wiki/GW170817#Scientific_importance https://en.wikipedia.org/wiki/Nucleosynthesis#Neutron_star_collision https://en.wikipedia.org/wiki/Nucleosynthesis#Neutron_star_c...