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Traveling across interstellar distances is not sci fi, at least not the act itself. What is sci-fi is an engine capable of accelerating for a sufficiently long

Traveling across interstellar distances is not sci fi, at least not the act itself. What is sci-fi is an engine capable of accelerating for a sufficiently long period of time. Something people often mistake is that the speed of light is a hard cap on travel rates. It's more complex. More educated individuals tend to think that as objects approach the speed of light, their mass approaches infinity - that is correct from the perspective of an observer. But from the perspective of something continually approaching the speed of light, there is no effect on your mass. This is where time dilation and space contraction come into the picture. Anyhow, setting aside all of that stuff the important thing is that if we can manage to generate engines capable of creating fairly modest acceleration (e.g. 1g) then interstellar travel is completely possible within a single human lifetime. There is a calculator here [1]. The relativistic effects are exponential but to give some examples: - 100 light years of travel = 9 years of 1g acceleration - 1000 light years of travel = 13 years of 1g acceleration - 1 million light years of travel = 26 years of 1g acceleration - 15 billion light years of travel = 45 years of 1g acceleration To be clear this gets into the fun time games of relativity though. Though you may be able to travel 15 billion light years in one human lifetime, from the perspective of an at rest observer (such as everybody back on Earth) - 45 billion years of time will indeed pass during your 45 year journey. So, for instance, the sun will have long since turned into a red giant by the time you arrive. This leads to really interesting 'paradoxes'. You could leave Earth on your relativistic starship towards some system billions of light years away. And when you get there you find that the system is completely colonized and hyper modern. Earthlings that left a million years after you got there first and colonized the system millions of years ago. They traveled at 2g acceleration... Reality is much stranger than any sort of fiction. But anyhow of course the issue is just discovering a technology to enable years of 1g acceleration. And while that may be far away, I think few would argue it's something that will ultimately prove to be impossible. [1] - http://convertalot.com/relativistic_star_ship_calculator.html http://convertalot.com/relativistic_star_ship_calculator.htm...

leetcrew 8y ago
even if such travel became possible, what could motivate anyone to actually do it at scale? if they're anything like humans, there would probably be a few crazy beings who would do it just to do something extreme, but aside from escaping a dying world, i can't see any reason why such a journey would be attempted at scale. what's the point of having a galaxy spanning civilization when the origin system would be destroyed every time you made a roundtrip?
- flukus 8y ago
  > if they're anything like humans, there would probably be a few crazy beings who would do it just to do something extreme, but aside from escaping a dying world, i can't see any reason why such a journey would be attempted at scale. How about the promise of future prosperity for whatever your group was, having a whole planets resources at your disposal? If we look at human history it's full of mass migrations, the colonization of the new world (original and 16th century) and the migration period (https://en.wikipedia.org/wiki/Migration_Period https://en.wikipedia.org/wiki/Migration_Period) come to mind. These weren't just a few thrill seekers but hundreds of thousands/millions of people.
- TangoTrotFox 8y ago
  I've had this conversation before and something interesting is that I think there may be a genetic component here, which can make empathy, in either direction, somewhat difficult. From my perspective, the question is who wouldn't go on such a voyage? Are you not curious what the universe really looks like? What unknown phenomena or other curiosities are out there? To me this is literally the meaning of life. Intellectual curiosity, challenging yourself, adventure. Not to mention that finding a place where your vessel could settle would mean being able to start an entirely new branch of our species created with the wisdom of and knowledge of a species' existence of efforts beforehand. I think all of these urges played a critical role both in our evolution and our global expansion. Beyond this there are also more material motivations as well. Of course there will be people simply seeking a better life, and a demographic that's yet to be created is those seeking immortality. Relativistic travel enables the possibility of traveling 'into the future'. People throughout time have engaged in all sorts of behavior to try to extend their lives. Relativistic travel is perhaps the most likely to achieve such ends since it would enable access to future technologies. In the future I'd expect to see many of the wealthiest on Earth directing a disproportionate amount of their funds to space technology to this end. This could even be happening in the present, but that'd be beyond the realm of even wild speculation.
stickfigure 8y ago
But anyhow of course the issue is just discovering a technology to enable years of 1g acceleration. And while that may be far away, I think few would argue it's something that will ultimately prove to be impossible. Why do you think this is possible? The argument in favor seems to be something along the lines of "well we can sustain 1G for a few hours, we just need to extend that". But right now there's not even a roadmap to building such a device... and when you factor in all the other issues (life support, materials longevity), it seems to be constructed of pure optimism. "It's not possible" seems like a perfectly plausible explanation for Fermi's paradox. The alternative seems less plausible - that's why it's called a paradox.
- TangoTrotFox 8y ago
  A paradox is most commonly just a self refuting but otherwise logical and sound statement that seems to be true. So there are problems whether you 'accept' or 'deny' the statement. This statement is false. is a good example. It being false or true poses problems. Everything we know leads us to believe that there should be extraterrestrial civilizations everywhere. That's a paradox because again whether true or false, it poses problems. If false, then where is the mistake we have made? If true, then why do we see no evidence of such civilizations? Interstellar travel is nothing particularly special. The voyager probes, launched using 70s era tech that was not designed to last anywhere near this long, are making it to interstellar space with no problem and still happily transmitting on top of it. Those probes will end up eventually being trapped in the orbit of some other body, and orbit it. They're not just going to disintegrate. This means we've already left a calling card in interstellar space. And that card was sent from less than 20 years after we learned how to put anything into space. Think about how much more we will put into space, and interstellar space, over the next 100 years. Now imagine the next million years. And these timescales are all still just blinks of an eye on astronomic scale. The only issue is increasing acceleration. And there are already countless near tech 'roadmaps' to that. Laser propulsion, anti matter drives, fusion drives, etc. For instance we could do an entire manned Mars mission on a tiny fraction of a gram of anti matter reactant if we could start to control the lovely side effects like gamma ray radiation. And then when you start to imagine what we don't know... [1] - https://www.nasa.gov/exploration/home/antimatter_spaceship.html https://www.nasa.gov/exploration/home/antimatter_spaceship.h...

leetcrew 8y ago

even if such travel became possible, what could motivate anyone to actually do it at scale? if they're anything like humans, there would probably be a few crazy beings who would do it just to do something extreme, but aside from escaping a dying world, i can't see any reason why such a journey would be attempted at scale. what's the point of having a galaxy spanning civilization when the origin system would be destroyed every time you made a roundtrip?

flukus 8y ago
> if they're anything like humans, there would probably be a few crazy beings who would do it just to do something extreme, but aside from escaping a dying world, i can't see any reason why such a journey would be attempted at scale. How about the promise of future prosperity for whatever your group was, having a whole planets resources at your disposal? If we look at human history it's full of mass migrations, the colonization of the new world (original and 16th century) and the migration period (https://en.wikipedia.org/wiki/Migration_Period https://en.wikipedia.org/wiki/Migration_Period) come to mind. These weren't just a few thrill seekers but hundreds of thousands/millions of people.
TangoTrotFox 8y ago
I've had this conversation before and something interesting is that I think there may be a genetic component here, which can make empathy, in either direction, somewhat difficult. From my perspective, the question is who wouldn't go on such a voyage? Are you not curious what the universe really looks like? What unknown phenomena or other curiosities are out there? To me this is literally the meaning of life. Intellectual curiosity, challenging yourself, adventure. Not to mention that finding a place where your vessel could settle would mean being able to start an entirely new branch of our species created with the wisdom of and knowledge of a species' existence of efforts beforehand. I think all of these urges played a critical role both in our evolution and our global expansion. Beyond this there are also more material motivations as well. Of course there will be people simply seeking a better life, and a demographic that's yet to be created is those seeking immortality. Relativistic travel enables the possibility of traveling 'into the future'. People throughout time have engaged in all sorts of behavior to try to extend their lives. Relativistic travel is perhaps the most likely to achieve such ends since it would enable access to future technologies. In the future I'd expect to see many of the wealthiest on Earth directing a disproportionate amount of their funds to space technology to this end. This could even be happening in the present, but that'd be beyond the realm of even wild speculation.

stickfigure 8y ago

But anyhow of course the issue is just discovering a technology to enable years of 1g acceleration. And while that may be far away, I think few would argue it's something that will ultimately prove to be impossible. Why do you think this is possible? The argument in favor seems to be something along the lines of "well we can sustain 1G for a few hours, we just need to extend that". But right now there's not even a roadmap to building such a device... and when you factor in all the other issues (life support, materials longevity), it seems to be constructed of pure optimism. "It's not possible" seems like a perfectly plausible explanation for Fermi's paradox. The alternative seems less plausible - that's why it's called a paradox.

TangoTrotFox 8y ago
A paradox is most commonly just a self refuting but otherwise logical and sound statement that seems to be true. So there are problems whether you 'accept' or 'deny' the statement. This statement is false. is a good example. It being false or true poses problems. Everything we know leads us to believe that there should be extraterrestrial civilizations everywhere. That's a paradox because again whether true or false, it poses problems. If false, then where is the mistake we have made? If true, then why do we see no evidence of such civilizations? Interstellar travel is nothing particularly special. The voyager probes, launched using 70s era tech that was not designed to last anywhere near this long, are making it to interstellar space with no problem and still happily transmitting on top of it. Those probes will end up eventually being trapped in the orbit of some other body, and orbit it. They're not just going to disintegrate. This means we've already left a calling card in interstellar space. And that card was sent from less than 20 years after we learned how to put anything into space. Think about how much more we will put into space, and interstellar space, over the next 100 years. Now imagine the next million years. And these timescales are all still just blinks of an eye on astronomic scale. The only issue is increasing acceleration. And there are already countless near tech 'roadmaps' to that. Laser propulsion, anti matter drives, fusion drives, etc. For instance we could do an entire manned Mars mission on a tiny fraction of a gram of anti matter reactant if we could start to control the lovely side effects like gamma ray radiation. And then when you start to imagine what we don't know... [1] - https://www.nasa.gov/exploration/home/antimatter_spaceship.html https://www.nasa.gov/exploration/home/antimatter_spaceship.h...