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>And then I better understood the stupendous energy requirements for a two-way trip to even the very closest neighboring solar system. And it is just not practi

>And then I better understood the stupendous energy requirements for a two-way trip to even the very closest neighboring solar system. And it is just not practical, even for a civilization at the end of the technology development tree. This is blind arrogance.

ansible 6y ago
Eh, no it isn't arrogance. It is math and physics. Have a look at a few links. So first off, chemical propulsion is right out: https://blogs.scientificamerican.com/life-unbounded/why-chemical-rockets-and-interstellar-travel-dont-mix/ https://blogs.scientificamerican.com/life-unbounded/why-chem... You really need something like anti-matter: https://en.wikipedia.org/wiki/Interstellar_travel https://en.wikipedia.org/wiki/Interstellar_travel You're still looking at hundreds of years or more for a nearby two-way trip. It is far more practical to send out probes one-way (which is quite slow), and then build the infrastructure at the destination to receive transmitted mind-states. The initial probes take a long time to reach their destinations, because they have to have means to deaccelerate. The faster you accelerate, the more mass you have to carry with you to deaccelerate.
- felixchan 6y ago
  It's arrogance because you think that your current system of science is relevant. Civilization has been around for only 5000 years. How do you know other planets do not have elements that have anti-matter properties?
  - ansible 6y ago
    > It's arrogance because you think that your current system of science is relevant. Civilization has been around for only 5000 years. So, if magic exists, there also might be aliens. Got it. > How do you know other planets do not have elements that have anti-matter properties? Well, we haven't observed anything that gives even a hint that something like that exists. The matter / antimatter disparity is still quite a mystery. But we don't see any evidence of antimatter out there in any significant quantities. So if aliens want to use it, they have to make it the hard way, just like we do. Beyond current state-of-the-art technology would make manufacturing and containment of antimatter easier, but even then it is a long way from practical.
    - felixchan 6y ago
      Sounds like you sure know how aliens make things.
      - ansible 6y ago
        And it sounds like you are sure the laws of physics don't apply to aliens. Extraordinary claims require extraordinary evidence.
        maxharris 6y ago
        Even Isaac Arthur did a video on the Navy's videos, and he's more open to this than you. Please give this a rest -
        postalrat 6y ago
        You've already proven when present with extraordinary evidence your reply will remain "Extraordinary claims require extraordinary evidence."
        davidivadavid 6y ago
        The whole point is that we don't know what the laws of physics are.
- eloff 6y ago
  It's our current understanding of physics. Those limitations might be impassable. Or it might be possible that there is a higher physics where things like the speed of light are bypassed. Like discovering that quantum entanglement is based on some mechanism that can be manipulated to communicate faster than light, or one can skip over distances through higher dimensions, or we decode the source code of the automata that creates the universe and it's immediately replaced by one even more bizarre. There are some theories that this has already happened :) The point is it's arrogant to say what's impossible for all time, because nearly everything we do today was impossible a short thousand years ago.
  - ansible 6y ago
    > The point is it's arrogant to say what's impossible for all time, because nearly everything we do today was impossible a short thousand years ago. I never said impossible, I said impractical. If you are content with really long travel times (thousands or tens of thousands of years one-way), then of course you can travel to other stars. By the time such means are available, I doubt that entities will bother with shipping matter two ways over such distances. Also, if you're talking about an uploaded or otherwise synthetic consciousness, that entity may be experiencing time a 100x or more faster than a baseline human does now. So a then thousand year trip would seem like a million years. That's a long time to stay away.
    - eloff 6y ago
      That seems likely from our perspective, but it's pretty arrogant to think we understand the limitations and desires of civilizations millions or even billions of years ahead of us. Certainly we would have failed at that task of predicting our own limits and desires just hundreds of years ago, nevermind an alien race.
  - jerf 6y ago
    I think it's important to break the conversation clearly into two parts: Here's what could be true about aliens if we're largely correct about physics, and here's what could be true ignoring that constraint. The problem is people want to have really muddled conversations about that. The people having the second kind of conversation yelling at the people having the first kind of conversation is probably the most frustrating element of all, especially when they strike a morally superior pose which is, IMHO, entirely unjustified. If you want to ignore all current science and astrophysics when you discuss aliens... fine. Be my guest. No sarcasm. I have some beliefs on that front myself. BUT... you need to be aware that you're basically engaging in groundless speculation, and in particular, you have no grounds to be yelling at people about their groundless speculation. We can have a much more grounded discussion about what aliens could look like if we are largely correct about science. And there's no need to accuse people about being "arrogant" if they choose to have that discussion, because frankly, of the two, it's the more interesting one. The "well, what if we're wrong about everything?" may seem like fun for a moment, but there's no there there, really. What if we're wrong about everything? Well, what if we are? What if we're all just in an ancestor simulation... but the descendants running it are super-advanced honey bees running their ancestors and we just happen to be around? Well... what if? There's nowhere to go, or if you prefer, there's nowhere you can't go, which is actually the exact same thing. On the other hand, if we stick to biology and cosmology and relativity and science in general, we can have all sorts of interesting discussions. What about that result on Venus? That's a question rich enough to build a concrete career on. What would aliens look like in our real universe? How much more advanced could they be? Would they, in fact, build rather human-sized spaceships that are apparently capable of crossing the interstellar void, but not flying around in our atmosphere without crashing into things? Would they in fact need to keep kidnapping humans over and over for decades on end? Sensible discussions can be had on these matters if we start from a concrete base. The whole "But what if we're, like, wrong about everything and we're, like, actually soap bubbles floating in the wind?" discussion has nowhere interesting to go, because it creates just one big undifferentiated and indistiguishable mismash of what ifs.
- deleted 6y ago
  [deleted]

ansible 6y ago

Eh, no it isn't arrogance. It is math and physics. Have a look at a few links. So first off, chemical propulsion is right out: https://blogs.scientificamerican.com/life-unbounded/why-chemical-rockets-and-interstellar-travel-dont-mix/ https://blogs.scientificamerican.com/life-unbounded/why-chem... You really need something like anti-matter: https://en.wikipedia.org/wiki/Interstellar_travel https://en.wikipedia.org/wiki/Interstellar_travel You're still looking at hundreds of years or more for a nearby two-way trip. It is far more practical to send out probes one-way (which is quite slow), and then build the infrastructure at the destination to receive transmitted mind-states. The initial probes take a long time to reach their destinations, because they have to have means to deaccelerate. The faster you accelerate, the more mass you have to carry with you to deaccelerate.

felixchan 6y ago
It's arrogance because you think that your current system of science is relevant. Civilization has been around for only 5000 years. How do you know other planets do not have elements that have anti-matter properties?
- ansible 6y ago
  > It's arrogance because you think that your current system of science is relevant. Civilization has been around for only 5000 years. So, if magic exists, there also might be aliens. Got it. > How do you know other planets do not have elements that have anti-matter properties? Well, we haven't observed anything that gives even a hint that something like that exists. The matter / antimatter disparity is still quite a mystery. But we don't see any evidence of antimatter out there in any significant quantities. So if aliens want to use it, they have to make it the hard way, just like we do. Beyond current state-of-the-art technology would make manufacturing and containment of antimatter easier, but even then it is a long way from practical.
  - felixchan 6y ago
    Sounds like you sure know how aliens make things.
    - ansible 6y ago
      And it sounds like you are sure the laws of physics don't apply to aliens. Extraordinary claims require extraordinary evidence.
      - maxharris 6y ago
        Even Isaac Arthur did a video on the Navy's videos, and he's more open to this than you. Please give this a rest -
      - postalrat 6y ago
        You've already proven when present with extraordinary evidence your reply will remain "Extraordinary claims require extraordinary evidence."
      - davidivadavid 6y ago
        The whole point is that we don't know what the laws of physics are.
eloff 6y ago
It's our current understanding of physics. Those limitations might be impassable. Or it might be possible that there is a higher physics where things like the speed of light are bypassed. Like discovering that quantum entanglement is based on some mechanism that can be manipulated to communicate faster than light, or one can skip over distances through higher dimensions, or we decode the source code of the automata that creates the universe and it's immediately replaced by one even more bizarre. There are some theories that this has already happened :) The point is it's arrogant to say what's impossible for all time, because nearly everything we do today was impossible a short thousand years ago.
- ansible 6y ago
  > The point is it's arrogant to say what's impossible for all time, because nearly everything we do today was impossible a short thousand years ago. I never said impossible, I said impractical. If you are content with really long travel times (thousands or tens of thousands of years one-way), then of course you can travel to other stars. By the time such means are available, I doubt that entities will bother with shipping matter two ways over such distances. Also, if you're talking about an uploaded or otherwise synthetic consciousness, that entity may be experiencing time a 100x or more faster than a baseline human does now. So a then thousand year trip would seem like a million years. That's a long time to stay away.
  - eloff 6y ago
    That seems likely from our perspective, but it's pretty arrogant to think we understand the limitations and desires of civilizations millions or even billions of years ahead of us. Certainly we would have failed at that task of predicting our own limits and desires just hundreds of years ago, nevermind an alien race.
- jerf 6y ago
  I think it's important to break the conversation clearly into two parts: Here's what could be true about aliens if we're largely correct about physics, and here's what could be true ignoring that constraint. The problem is people want to have really muddled conversations about that. The people having the second kind of conversation yelling at the people having the first kind of conversation is probably the most frustrating element of all, especially when they strike a morally superior pose which is, IMHO, entirely unjustified. If you want to ignore all current science and astrophysics when you discuss aliens... fine. Be my guest. No sarcasm. I have some beliefs on that front myself. BUT... you need to be aware that you're basically engaging in groundless speculation, and in particular, you have no grounds to be yelling at people about their groundless speculation. We can have a much more grounded discussion about what aliens could look like if we are largely correct about science. And there's no need to accuse people about being "arrogant" if they choose to have that discussion, because frankly, of the two, it's the more interesting one. The "well, what if we're wrong about everything?" may seem like fun for a moment, but there's no there there, really. What if we're wrong about everything? Well, what if we are? What if we're all just in an ancestor simulation... but the descendants running it are super-advanced honey bees running their ancestors and we just happen to be around? Well... what if? There's nowhere to go, or if you prefer, there's nowhere you can't go, which is actually the exact same thing. On the other hand, if we stick to biology and cosmology and relativity and science in general, we can have all sorts of interesting discussions. What about that result on Venus? That's a question rich enough to build a concrete career on. What would aliens look like in our real universe? How much more advanced could they be? Would they, in fact, build rather human-sized spaceships that are apparently capable of crossing the interstellar void, but not flying around in our atmosphere without crashing into things? Would they in fact need to keep kidnapping humans over and over for decades on end? Sensible discussions can be had on these matters if we start from a concrete base. The whole "But what if we're, like, wrong about everything and we're, like, actually soap bubbles floating in the wind?" discussion has nowhere interesting to go, because it creates just one big undifferentiated and indistiguishable mismash of what ifs.
deleted 6y ago
[deleted]