a peaceful place, or so it looks from space
????
A closer look reveals the human race.
I have always LOVED this topic. Wonderful brain exercise!
I find it interesting as well. Do some reading on time dilation. If constant acceleration were to be achieved, interstellar trips are quite possible in a lifetime but many lifetimes will have passed on earth. You reach relativistic speeds at around one year of 1g acceleration. I knew this, as likely did you, but never realized till lately just how much time would be shortened for the travelers. Never realized that generation ships were not necessary, but that the star troopers would leave the rest of us behind.
"Physicists generally believe faster-than-light travel is impossible. Relativistic
time dilation allows a traveler to experience time more slowly, the closer their speed is to the speed of light.
[35] This apparent slowing becomes noticeable when velocities above 80% of the speed of light are attained. Clocks aboard an interstellar ship would run slower than Earth clocks, so if a ship's engines were capable of continuously generating around 1 g of acceleration (which is comfortable for humans), the ship could reach almost anywhere in the galaxy and return to Earth within 40 years ship-time (see diagram). Upon return, there would be a difference between the time elapsed on the astronaut's ship and the time elapsed on Earth.
For example, a spaceship could travel to a star 32 light-years away, initially accelerating at a constant 1.03g (i.e. 10.1 m/s2) for 1.32 years (ship time), then stopping its engines and coasting for the next 17.3 years (ship time) at a constant speed, then decelerating again for 1.32 ship-years, and coming to a stop at the destination. After a short visit, the astronaut could return to Earth the same way. After the full round-trip, the clocks on board the ship show that 40 years have passed, but according to those on Earth, the ship comes back 76 years after launch.
From the viewpoint of the astronaut, onboard clocks seem to be running normally. The star ahead seems to be approaching at a speed of 0.87 light years per ship-year. The universe would appear contracted along the direction of travel to half the size it had when the ship was at rest; the distance between that star and the Sun would seem to be 16 light years as measured by the astronaut.
At higher speeds, the time on board will run even slower, so the astronaut could travel to the center of the
Milky Way (30,000 light years from Earth) and back in 40 years ship-time. But the speed according to Earth clocks will always be less than 1 light year per Earth year, so, when back home, the astronaut will find that more than 60 thousand years will have passed on Earth."
en.wikipedia.org
So, 40 years have passed for a round trip to a star 32 light years away, according to that article. That's "faster than light" for the travelers. Other wiki pages show travel to our nearest stars at 3-4 years ship time with constant acceleration.
This is fascinating stuff for making up science fictions stories in your head. Star travelers in one lifetime is possible, but you leave our earth and species behind.
So, aliens thus might be operating under this little loophole as well if you're into all that.
Not sure I believe in aliens myself. My psychic told me that was bunk.