"The fact that heavy elements were plentiful only 5 billion years after the big bang is a very good sign about the possibility of alien-life evolving in the very earlier universe. But of course that then leads to the annoying and now cliche Fermi paradoxical question: If alien life had several billion years to get started earlier than we might have initially expected, then where the heck are they? Consider this: If a hyper intelligent civilization arose when the universe was only 5 billion years old, then it should have had time to effectively colonize every galaxy in the universe, simply by sending out replicating-machines and probes to every visible galaxy at once, simultaneously. And of course once each probe reached the target galaxy, it would only take a few hundred thousands years (or perhaps a couple of million years at most) to establish replicating probes in every star system of that galaxy. So really once life reaches hyper intelligence, then it doesn't take very long to colonize not only a single galaxy, but the entire universe. Thus there really should be aliens amongst us.
"I once read a theory that says it is far more likely we are living in a simulation, as opposed to the "real" universe. The reasoning behind that is simply this: imagine that there is a vast universe, in which a few million hyper intelligent civilizations have evolved, that have computer technology. Each of those civilizations will in turn likely run billions of simulations. Thus if you look at the numbers: there are only a few million "real" civilizations, and multiple billions (probably trillions!) of simulated civilizations. Ergo, the odds are much greater that an individual will exist in a simulated universe, rather than the real universe. Suddenly I'm beginning to think that the lack of evidence of aliens, may simply be that we are indeed a simulation, and aliens are not programmed into this particular simulation! Probability/mathematically this is beginning to sound like the most reasonable explanation... But it's also the explanation I am most uncomfortable with, so I hope it is wrong!"