> If we could ever produce such matter then we could start some spacetime engineering.
Imagine the exotic "pollution" caused by civilizations which are advanced enough to tinker with the fabric of spacetime, but not advanced enough to understand (or care about) the long-term consequences of that tinkering.
Destabilizing solar systems or even entire galaxies, maybe even violating causality..
Imagine the home (and only) planets of younger, insignificant civilizations being caught up in those cataclysms, all traces of their existence wiped from cosmic history in what might amount to the equivalent of a traffic accident or "oil spill" of a greater civilization.
..maybe that has already happened and some of the leviathanic voids we've observed were a result of that? :)
Imagine the exotic "pollution" caused by civilizations which are advanced enough to tinker with the fabric of spacetime, but not advanced enough to understand (or care about) the long-term consequences of that tinkering.
Destabilizing solar systems or even entire galaxies, maybe even violating causality..
Imagine the home (and only) planets of younger, insignificant civilizations being caught up in those cataclysms, all traces of their existence wiped from cosmic history in what might amount to the equivalent of a traffic accident or "oil spill" of a greater civilization.
..maybe that has already happened and some of the leviathanic voids we've observed were a result of that? :)
[0] https://en.wikipedia.org/wiki/Void_(astronomy)