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How about: The physical laws of the universe just don't allow a practical way for us to interact. "Space is big." Science fiction authors can imagine all sorts

How about: The physical laws of the universe just don't allow a practical way for us to interact. "Space is big." Science fiction authors can imagine all sorts of ways we could communicate or travel across interstellar distances, but really we have no idea how to build them. Maybe there just isn't some new discovery to be had.

TangoTrotFox 8y ago
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.
InclinedPlane 8y ago
Fermi's paradox roughly goes like this: Even if technological life is very uncommon, even if civilizations which colonizes the galaxy are uncommon among technological civilizations, even if galactic colonization is extremely slow and limited, on astronomical timescales it would still be trivial to colonize essentially every star in our own galaxy. From this we can conclude that there have been no colonizing civilizations in existence in the Milky Way at least prior to a few hundred million years ago because otherwise they would be everywhere including here (Earth, our Solar System). So either long-lived colonizing technological civilizations are vastly uncommon to an incredible degree (due to some internal or external factor limiting their longevity, perhaps), technological civilizations are far more alien than we could imagine, or humans happen to be one of the earliest technological civilizations in the Milky Way. Nothing in Fermi's paradox requires technology or physics that doesn't exist yet, it primarily relies on time. A million years is a long time for a technologically advanced species, ten million, 100 million, or a billion years is an unimaginable eternity. Even at slow travel times and very "half-assed" levels of colonization (taking thousands of years between founding a colony and sending out only a handful of new colony ships) the sheer amount of time in play allows for quite thorough colonization of the entire Milky Way.
- stickfigure 8y ago
  even if civilizations which colonizes the galaxy are uncommon Colonizing the galaxy requires technology that does not exist yet. Even putting a single live human temporarily on Mars requires technology that does not exist yet.
  - InclinedPlane 8y ago
    Pressure vessels, life support systems, rockets, what exactly doesn't exist yet that is needed, technologically? If you want to be a pedant and say that any specific tool that doesn't exist yet represents technology that doesn't exist then sure, that's the case, but there's nothing especially beyond state of the art that is required to live in space or colonize other planets. Technological advancements are mainly advantageous in increasing the success rate and cost efficiency of doing so. But we could have sent people to Mars in the 1970s. We had the rockets, we had the know-how to build the vehicles.

TangoTrotFox 8y ago

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.

InclinedPlane 8y ago

Fermi's paradox roughly goes like this: Even if technological life is very uncommon, even if civilizations which colonizes the galaxy are uncommon among technological civilizations, even if galactic colonization is extremely slow and limited, on astronomical timescales it would still be trivial to colonize essentially every star in our own galaxy. From this we can conclude that there have been no colonizing civilizations in existence in the Milky Way at least prior to a few hundred million years ago because otherwise they would be everywhere including here (Earth, our Solar System). So either long-lived colonizing technological civilizations are vastly uncommon to an incredible degree (due to some internal or external factor limiting their longevity, perhaps), technological civilizations are far more alien than we could imagine, or humans happen to be one of the earliest technological civilizations in the Milky Way. Nothing in Fermi's paradox requires technology or physics that doesn't exist yet, it primarily relies on time. A million years is a long time for a technologically advanced species, ten million, 100 million, or a billion years is an unimaginable eternity. Even at slow travel times and very "half-assed" levels of colonization (taking thousands of years between founding a colony and sending out only a handful of new colony ships) the sheer amount of time in play allows for quite thorough colonization of the entire Milky Way.

stickfigure 8y ago
even if civilizations which colonizes the galaxy are uncommon Colonizing the galaxy requires technology that does not exist yet. Even putting a single live human temporarily on Mars requires technology that does not exist yet.
- InclinedPlane 8y ago
  Pressure vessels, life support systems, rockets, what exactly doesn't exist yet that is needed, technologically? If you want to be a pedant and say that any specific tool that doesn't exist yet represents technology that doesn't exist then sure, that's the case, but there's nothing especially beyond state of the art that is required to live in space or colonize other planets. Technological advancements are mainly advantageous in increasing the success rate and cost efficiency of doing so. But we could have sent people to Mars in the 1970s. We had the rockets, we had the know-how to build the vehicles.