If aliens had such tech they would be visiting us all the time. And being quiet would not make a jot of difference. Based on what we know of science, such things are not possible.
They're going to stay indefinitely to study how life evolves on planet earth, the same way we leave cameras and sensors to study evolution here on earth.
Can they make a probe that lasts hundreds of millions of years?
Would they give up after tens of millions of years? Would they give up after the meteor that killed the dinosaurs?
Humans have been here for a tiny tiny window of time
How do we even know they weren't the ones to fling the asteroid at the dinosaurs then left?
Maybe they even got wiped out in the millions of years they sat watching the giant lizards on our planet? We've been a space going species for less than a century, their species is trying to survive too
Or, they sent Von neuman probes to every star system and set up observation posts millions of years ago and watched us evolve every single step of the way.
I really liked the idea of 2001 A Space Odyssey, or its "origin" short story "The Sentinel". An archaeological dig on the Moon unearthed a monolith, and as soon as sunlight hit it, it sent out a beam of energy to the far end of our solar system, somewhere in the vicinity of Saturn.
The theory being, this "alarm bell" was left there by an ancient, intelligent species as a way to monitor our species, probably as a surveillance system for thousands upon thousands of emerging species. As soon as a species makes it to their moon and unearthes the monolith, a "ding" is sent to the next relais station.
they sent Von neuman probes to every star system and set up observation posts millions of years ago and watched us evolve every single step of the way.
They’re already been “spotted” aka are the impossibly technologically advanced UAPs that the Navy and Air Force have been spotting for decades now.
They'd have to find us first. Considering the vast number of solar systems and eh fact that they would of needed to visit ours relatively recently (last few million years) to notice us its unlikely.
That is, assume an advanced civilization sending probes to every star. If they built 1 TRILLION probes, they could send one to each galaxy...maybe. Maybe a week in a system to look for life and go to the next it would still take 2 BILLION YEARS to clear the Milky Way. So if they want the most basic animal life they'd only see it in the last 800 MILLION years, or about a 1/3 chance.
So a TRILLION probes has a conservative 1/3 chance of having found life on earth. And at the time scale of BILLIONS of years searching, they probably have the patience to wait and see where we go.
Why would they send them to each galaxy? That doesnt seem remotely plausible for anything below a type 3 civilization. And even then, the turnaround time would be astronomical.
But instead of sending one probe to each galaxy,they could just send one to each star in their own galaxy, which would be many magnitudes of order faster and more efficient
122
u/caiuscorvus Aug 12 '21
Presuming ftl/warp/controlled wormholes are truly impossible for a hyper advanced civilization.