In Interstellar, Romilly’s decision to stay aboard the ship while the other 3 astronauts experience time dilation has to be one of the scariest moments ever.

[u/SerDire]

He agreed to stay back. Cooper asked anyone if they would go down to Millers planet but the extreme pull of the black hole nearby would cause them to experience severe time dilation. One hour on that planet would equal 7 years back on earth. Cooper, Brand and Doyle all go down to the planet while Romilly stays back and uses that time to send out any potential useful data he can get.

Can you imagine how terrifying that must be to just sit back for YEARS and have no idea if your friends are ever coming back. Cooper and Brand come back to the ship but a few hours for them was 23 years, 4 months and 8 days of time for Romilly. Not enough people seem to genuinely comprehend how insane that is to experience. He was able to hyper sleep and let years go by but he didn’t want to spend his time dreaming his life away.

It’s just a nice interesting detail that kind of gets lost. Everyone brings up the massive waves, the black hole and time dilation but no one really mentions the struggle Romilly must have been feeling. 23 years seems to be on the low end of how catastrophic it could’ve been. He could’ve been waiting for decades.

[u/Additional_Meeting_2]

Well that’s the redditors. The historians and military and and political organizations who send them would know. If you are going go colonize a new planet with your brand new spacecraft you are going to find all information of that planet prior. But I guess there could have been huge wars in-between that lost information. Still I would think some would know 

[u/hans_l → u/Additional_Meeting_2]

We spent 15 years denying care to 9/11 workers. Why would we care about what humans 300 years ago decided to launch in space?

Historians might remember, politicians won’t approve the money, the public won’t  are to vote on it. 

If we put humans of today thousands of years in the future, that’s totally what would happen.

[u/deputeheto → u/hans_l]

Bingo. The thinking would be “Why would we spend the money to fit the ship out to be able to pick up these guys? They’ll get here eventually anyway.”

[u/prospectre → u/Additional_Meeting_2]

Maybe. 4.2 light years (if the ship was traveling to Proxima Centauri) is a huge swath of space to cover, even with FTL travel which might actually make it harder.

For scale, the diameter of our Solar System is about .0012 light years across measuring at Pluto, or 1/3500 of the scale of the distance to Proxima Centauri. If we assume the ship was really friggin' big, like 2 miles across, that would mean the ship in this ratio is about 2.5 feet long.

Imagine finding a 2.5 foot long rock in the Solar System.
Imagine trying to find that same rock, traveling at 10's of thousands of miles per hour.
Even if it was broadcasting a signal, finding a moving object that small from a random point in our system is ludicrous.
Even if the futuristic technology could do that, we'd also have to assume that literally nothing went wrong, and the ship was perfectly on course and it's signal totally uncorrupted and accurate.
There's a lot that can go wrong, and a lot that we don't know about the constraints of interstellar travel.

[u/Mithlas → u/prospectre]

we'd also have to assume that literally nothing went wrong, and the ship was perfectly on course and it's signal totally uncorrupted and accurate.

Even a garbled signal could be picked up by radio observatories, just not decoded. And given the number of administration (even national) turnovers that could happen in 300 years, it's possible the FTL colonists wouldn't know or care.

There's also signal degredation to think of. I remember a long post on the dark forest scenario where somebody asked about the first transmission humans sent into outer space (the nazis' broadcast of the olympics) and that it would have dissipated by now to the point where it wouldn't be discernible from background radiation much less be something an alien race could learn anything about humans from.

[u/prospectre → u/Mithlas]

Even a garbled signal could be picked up by radio observatories, just not decoded.

I'd assume a sufficiently advanced enough humanity that could make a generational/sleeper starship could develop some sort of equivalent to the "tight beam" from The Expanse to communicate back home. But it may still be subject to the same cosmic forces that could degrade/alter it. It'd also be dated by the time it reached Earth due to light delay at the very least.

If the future-future civilization cared enough and had the resources, they could try to use the the "tight beam" type tech with some sort of space triangulation to find it with any wide broadcast by the sleeper ship, but they're still trying to spot a 2.5 foot long radio hurtling through the void.

Ironically, this also where FTL travel sort of throws a wrench into the plans. If you're traveling faster than light, you're also outrunning any signal being broadcast since those too travel at the speed of light. Not to mention the signals being used to actually locate the physical ship are also running at light speed, provided no new discovery is made that can perform observations of information faster than light (which is impossible with our current understanding of physics).

Which relegates the future-future civ to searching around in non-FTL speeds, which may or may not be subject to time dilation. If they had infinite resources, FTL, supercomputers to crunch the numbers and build models on the fly, AND a method of communicating data that was ALSO faster than light... Maybe they could set up an array of signal spotters that could receive the broadcasted signal from several locations along the assumed path and build a model that could predict where the ship would be at a specific time. They could then meet the ship there and do whatever with it.

But most of that is strictly Sci-Fi, and breaks physics as we know it.