Comment by jajko
8 days ago
This is something I don't get - solar system is say 5 billions years old (a bit less I know). Universe is roughly 13 billions, and our Milky way almost the same.
What this means is that there must have been quite a few collisions of such before solar system formed, to produce so much of heavy stuff we see in our planet, no? Stars can produce only up to Fe in normal way. Yet it seems such collisions are very rare, and its not like during collision half of the mass converts to a golden blob (or more like atomic mist spreading away at fraction of c).
I know 8 billions of years is a long time, and gold once fused ain't breaking apart to H or He anytime soon, but still it feels like our planet should have way more basic atoms and not all of those rare fused oned. What about super/hypernovae?
In what appears to be a fairly recent discovery, it seems that flares on magnetars can produce gold and other heavy elements, and these are likely more frequent than neutron star collisions.
https://science.nasa.gov/universe/stars/neutron-stars/magnet...
Stars produce beyond Fe during supernova.
The other thing to keep in mind is that the early universe was filled with giant stars, these stars don't last very long. Ironically, the more fuel you have, the quicker you burn through it for stars, so a lot of supernova have happened before our solar system formed.
For additional reading, google "Stellar Population" it's about the amount of metalicity in a star based on how many "generations" old it is
There's also a lot of open questions about how stars and galaxies form and our current models are known to be extremely incomplete based on the JWST data and our knowledge of the upper bound of how old the universe is from repeated measurements of the CMB & other data. So there's definitely a lot unknown about the state of stars in the early universe and how everyday elements we know & love actually came to be in the quantities they did.