There are many middle possibilities between that and aliens expanding at c.
Expansion at c is very unlikely. Insane things happen when you approach c, like the cosmic microwave background transforming into a gamma ray laser aimed at your head and collisions with microscopic particles destroying you. It may be that travel close to c is so hard as to be effectively impossible.
I’ve read that speeds up to about 30% the speed of light are “thinkable” with currently known physics plus advances like compact fusion reactors. Think something that looks like the Epstein Drive in The Expanse or the ships from Avatar.
These models provide indirect evidence against the existence of FTL travel. If FTL exists it means we really have to be extremely early, maybe even the first in our galactic cluster. Otherwise someone would have visited at least.
I also think if someone has visited, such as if some tiny number of UFOs are actually of ET origin, it means we are probably incredibly lucky to have neighbors that aren’t “reapers” in the dark forest sense. It’d be funny if our galaxy is actually full of aliens and we lucked out and are camped next to some superintelligence that is both benevolent and powerful enough to fight off anyone who isn’t. So hey if they’re taking our cattle maybe that’s a pretty small price to pay.
Expansion at c is very unlikely. Insane things happen when you approach c, like the cosmic microwave background transforming into a gamma ray laser aimed at your head and collisions with microscopic particles destroying you. It may be that travel close to c is so hard as to be effectively impossible.
I’ve read that speeds up to about 30% the speed of light are “thinkable” with currently known physics plus advances like compact fusion reactors. Think something that looks like the Epstein Drive in The Expanse or the ships from Avatar.
These models provide indirect evidence against the existence of FTL travel. If FTL exists it means we really have to be extremely early, maybe even the first in our galactic cluster. Otherwise someone would have visited at least.
I also think if someone has visited, such as if some tiny number of UFOs are actually of ET origin, it means we are probably incredibly lucky to have neighbors that aren’t “reapers” in the dark forest sense. It’d be funny if our galaxy is actually full of aliens and we lucked out and are camped next to some superintelligence that is both benevolent and powerful enough to fight off anyone who isn’t. So hey if they’re taking our cattle maybe that’s a pretty small price to pay.