Here's a nice snappy discussion of the prospects, and consequences, of universe creation 'in a laboratory'. The (anonymous) author quotes my own paper on the subject, (always a wise move), and argues that
There is a non-trivial probability that humans or their descendants will create infinitely many new universes in a laboratory. Under plausible assumptions, this would, with probability one, entail the creation of infinitely many sentient organisms...My main concern is that the potential creators of lab universes would give insufficient consideration to the suffering that they would cause. They might think of the project as "cool" or "exciting" without thinking hard about the consequences for real organisms. I fear that, because potential universe creators would have lived generally happy lives--never having been brutally tortured, eaten alive, or slaughtered while conscious--they would be less sensitive to how bad pain can really be.