a counter to the fermi paradox

nanotechnology need to be self replicating to scale well

computer chips could use nanometer sized transistors 

but those computer chips won't create more computer chips 

machines create nanotechnology 

nanotechnology creates femtotechnology 

femtotechnology creates attotechnology 

attotechnology creates plancktech technology 

self replicating nano machines 

could disassemble asteroids and planets 

and could probably create everything humanity needs to colonize the galaxy

self replicating femto machines 

could disassemble stars 

and could probably create everything humanity needs to colonize the universe

self replicating attotech machines 

could probably disassemble black holes 

and could probably create portals to other parts of the universe 

self replicating plancktech machines 

could probably disassemble space itself and time itself 

and could probably create portals to other dimensions 

the technological turning point of a species occurs 

when that species creates self replicating nanotechnology 

then after that it's probably within decades 

that species creates self replicating femtotechnology 

then after that it's probably within decades 

that species creates self replicating attotechnology 

then after that it's probably within decades 

that species creates self replicating plancktech technology 

so if an alien species created self replicating nanotechnology millions of years before humanity 

then that alien species could atleast have colonized parts of one galaxy 

but if that galaxy is billions of light years away from earth 

then it would take billions of years before that would be visible to earth 

or if that galaxy is millions of light years away from earth 

then it would take millions of years before that would be visible to earth 

an alien species would probably be interested in controlling a whole galaxy or whole galaxies 

but why would an alien species need to colonize more than parts of different galaxies 

since it's possible to build lots of space station habitats within a single star system 

an alien species that invented self replicating nanotehnology millions of years ago and has had access to self replicating attotechnology for some time could have created portals and visited earth or communicated with earth 

but if that alien species is interested in controlling their own galaxies but not colonizing more than parts of their own galaxies 

then that would not make their possible activities in the milky way galaxy be visible to earth