We're not going beyond our solar system. Ever. The nearest star is 4 light-years away. Assuming you could even travel at the speed of light, which you can't, it takes 1 year to reach the speed of light while accelerating at a comfortable 1G. But, as I said, we're not ever traveling at the speed of light. 20% of the speed of light is about the best we'll realistically ever be able to do - but that still makes the nearest star over 20 years of travel away!
How do you propose to travel for over 20 years?
It's clear then that robots will be exploring the solar system, not us. Even then it's going to take several centuries just to travel to, collect data from, and send back to earth just from the local stars we can see with the unaided eye.
Sorry, that simply isn't true. Multi-generation starships don't violate any laws of physics.
> How do you propose to travel for over 20 years?
By recognizing that you aren't coming back, and that even if you don't make it there, your children will.
I mean, we have examples of this even here on Earth. Moses and the Israelites supposedly wandered for 40 years. The pioneers who set out on the Oregon Trail largely knew it was a one-way trip. Other examples abound..
> Multi-generation starships don't violate any laws of physics.
That's true - but they do violate what we know about psychology. You're signing on your progeny to be imprisoned on a ship from birth to death, when you yourself never had to endure that. Think about the sentiment behind the "Okay, Boomer..." memes and magnify that generational hatred several-fold. Someone is going to sabotage the ship and its crew long before they ever reach their destination. That's just how people work. Remember, we're not rational.
Yet they yearned for adventure - and many, many people went on such adventures. Now we live in an age of mass transportation where people routinely leave their towns to venture elsewhere. They take airplanes to fly to different parts of the world, they take their cars to go on trips, they go on cruises: they travel. They may live in the same town in which they grew up, but they've travelled quite further.
How is that going to work for your population confined to a ship the size of a small town? It isn't. It's science fiction.
> Now we live in an age of mass transportation where people routinely leave their towns to venture elsewhere
Future generations may grow up in a world of much more limited travel, existing in small areas of '15-minute cities' without cars, minimal access to air travel, living in tiny apartments, and most likely spending most of their time in some sort of metaverse, with very limited food choices. We'll have stopped burning fossil fuels and given most of the planet back to nature, and can't allow the working-class masses the transport/freedoms to access/enjoy/ruin it again.
If that's what the world comes to, it'll be a lot closer to life on a generation ship than the world we're used to today.
We're not going within my lifetime, but we don't know what currently-unimaginable technologies could be developed in the future (if we don't destroy our civilization within the next few decades)
Significantly extending the lifespan of humans seems inevitable at some point. Robotics and AI will continue to improve. We may master fusion, or discover new ways to store energy. We'll probably mine asteroids and master construction in space.
Robots will lead the way, but humans are unlikely to lose the urge to explore.
I'm sorry. We know physics very well. There's no "unimaginable technologies" that are going to be developed that gets us around the fact that we're not going to travel much faster than 20% of the speed of light - and that doesn't change the fact that the average star you see with your own eyes is 60-100 lightyears away and will by dying at roughly the same time as our sun.
The most important point to realize about science fiction is that it is fiction.
Our knowledge is incomplete, but we can put boundary boxes around what is possible. Just because our theories are incomplete doesn't mean that what we know is wrong. Our knowledge has been extensively tested over the past 100 years.
There are people that will be willing to lose decades of subjective time getting iced.
Or if we can't do that (which would be weird since many complex mammals can hibernate already) then generation ships are possible. It'll probably be only done by culturally crazy groups, but hey! They're still counted as humans, and their expanding human habitats into new systems is still a win to us all.
How do you propose to travel for over 20 years?
It's clear then that robots will be exploring the solar system, not us. Even then it's going to take several centuries just to travel to, collect data from, and send back to earth just from the local stars we can see with the unaided eye.
When they say space is big, space is BIG.