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I remember being in school in 2006 and being told that outside of our solar system is a "wall of fire" that we would never be able to cross. I don't know if an

I remember being in school in 2006 and being told that outside of our solar system is a "wall of fire" that we would never be able to cross. I don't know if any of this info was speculated at that point in time, but it turns out that teacher was at least partially correct!

relaxing 1y ago
That’s weird. What class was it and what was their motivation for telling you this?
jordanb 1y ago
Probably true, in that if you try to travel interstellar distances you'll going to have to deal with very hot particles hitting your ship on occasion. If you travel slowly the more time you're going to be spend getting hit by high energy particles. If you try to travel quickly you're going to have to deal with more relatively high energy particles. It's potentially enough to make interstellar travel impossible.
- SoftTalker 1y ago
  It's impossible for many reasons unless there are physics we haven't discovered yet. To me that's the simple answer for the Fermi paradox.
  - andrewflnr 1y ago
    The Fermi paradox doesn't require travel, though. The lack of any sign of life at all is still surprising (no radio signals, etc), even if we knew it couldn't physically come here.
    - flatline 1y ago
      It would take a lot of power to send even a radio signal that could be picked out from the noise at a few light years. Add a requirement for that signal to be more or less continuous over geologic timescales - we’ve only been able to emit and detect these for ~100 years - and my personal surprise diminishes rapidly. Huge distances in time and space with human-level technology make detection highly unlikely.
      - ojosilva 1y ago
        Yes, and I would add my favorite hypothesis to the paradox, an anthropocentric assumption theory of self importance... or let's call it an anthropocentric bias: Humans tend to define intelligence, life, and communication based on our own structure -carbon-based biology, electromagnetic signaling, language, symbolic thought, etc. This narrows the scope of our search. We assume other civilizations want to communicate, would use similar media (radio, light, mathematics), and would send signals we could interpret. This ignores other potential modalities (quantum, neutrino, gravitational, exotic matter, etc.) or entirely non-signal-based forms of interaction. We may not even recognize signs of intelligent activity if they don't resemble our expectations, ie entire civilizations could exist in forms of computation or energy we can’t perceive. We assume ET intelligences are aligned with our timeframe or curiosity. Maybe they don’t care to communicate, see us as trivial, or operate on million-year attention spans. It may reflect less the silence of the cosmos and more the limits of our understanding, especially the assumption that we're capable of detecting or interpreting intelligence beyond Earth. A epistemic humility, or rather our lack of it.
        esprehn 1y ago
        The counter argument is that even if civilizations exist with all the properties you described, given the vastness of space, there should be another civilization that pattern matches to us.
        ojosilva 1y ago
        Sure! All the hypothesis in the Fermi paradox deal ultimately with calibrating our expectations of making contact, not with denying the existence of "STEM-enabled" species like us yearning for an alien encounter.
        andrewflnr 1y ago
        There's epistemic humility, then there's indulging in unfalsifiable fantasies in the name of not ruling anything out. > Humans tend to define intelligence, life, and communication based on our own structure -carbon-based biology, electromagnetic signaling, language, symbolic thought, etc. I would posit that none of these properties are coincidences, and are in fact likely to evolve convergently in most if not all circumstances hospitable to life. In particular I very much expect ET life to be carbon based; I don't believe there's a true viable alternative outside scifi (hint: silicon ain't it). > entire civilizations could exist in forms of computation or energy we can’t perceive. Could they? Really? There aren't that many gaps in the Standard Model. The aliens could be made of dark matter, I guess, and remain forever undetectable, but that's not to far off believing in invisible fairy kingdoms. And it still wouldn't explain why the baryonic sector is so devoid of detectable life. Ethereal undetectable aliens don't mean regular ones can't also exist. > Maybe they don’t care to communicate, see us as trivial, or operate on million-year attention spans. This one I'll grant (sort of: what's the evolutionary path toward such entities arising?), but it's still weird that we haven't seen any sign at all of them. These entities live on million-year timescales but have no visible effect on their surroundings? Why? And more importantly, why is that the only thing that happens? Because if it isn't the only thing, then the question remains of why can't we see anything else?
- strictnein 1y ago
  Systems we built in the 1970s were able to easily pass through this though. Which doesn't seem to indicate that it would make interstellar travel impossible.
  - andrewflnr 1y ago
    Systems from the 1970s travel at, by interstellar standards, agonizingly slow speeds. The voyagers will be exposed to hard radiation for thousands of years before they get anywhere interesting. They will not survive.
    - strictnein 1y ago
      Not sure exactly why you're responding to me. The comment I was responding to was talking about the hot particles that would be encountered, and that their existence could preclude future interstellar missions. What level of "hard radiation" are they now getting bombarded by that we will be unable to shield systems from in far future interstellar space travel?
      - andrewflnr 1y ago
        I'm saying the Voyager probes don't make a counter example to interstellar travel being impossible. That's still very much an open question. We might be able to develop adequate shielding to protect spacecraft from radiation over mildly geologic timespans, but we might not. I'm certain it won't be as easy as you seem to think it is. (Unless you count slinging a dead pile of former computers through a distant star system as successful interstellar travel, but that's not what most people are interested in.)
        mxkopy 1y ago
        Imagine if a dead pile of computers that wasn’t ours arrived in our solar system, I’d call that successful by some metric
    - deleted 1y ago
      [deleted]
jauntywundrkind 1y ago
Also sort of the plot of Solar Winds (1993, Epic MegaGames). https://en.wikipedia.org/wiki/Solar_Winds https://en.wikipedia.org/wiki/Solar_Winds
deleted 1y ago
[deleted]
TeaBrain 1y ago
It's not a new idea. The posted article is just about Voyager apparently observing the phenomena more closely. Voyager 1 had already reached the termination shock of the heliosphere in 2004 and Voyager 2 in 2007. The heliosphere containing a heliosheath, past the boundary of the termination shock, composed of compressed superhot solar winds had been hypothesized, due to the compression of the solar winds that begins at the termination shock. Reading the article, the wall is referring to the heliopause, which is the boundary past the heliosheath. Also, it looks like both voyagers traveled past this over a decade ago.

relaxing 1y ago

That’s weird. What class was it and what was their motivation for telling you this?

jordanb 1y ago

Probably true, in that if you try to travel interstellar distances you'll going to have to deal with very hot particles hitting your ship on occasion. If you travel slowly the more time you're going to be spend getting hit by high energy particles. If you try to travel quickly you're going to have to deal with more relatively high energy particles. It's potentially enough to make interstellar travel impossible.

SoftTalker 1y ago
It's impossible for many reasons unless there are physics we haven't discovered yet. To me that's the simple answer for the Fermi paradox.
- andrewflnr 1y ago
  The Fermi paradox doesn't require travel, though. The lack of any sign of life at all is still surprising (no radio signals, etc), even if we knew it couldn't physically come here.
  - flatline 1y ago
    It would take a lot of power to send even a radio signal that could be picked out from the noise at a few light years. Add a requirement for that signal to be more or less continuous over geologic timescales - we’ve only been able to emit and detect these for ~100 years - and my personal surprise diminishes rapidly. Huge distances in time and space with human-level technology make detection highly unlikely.
    - ojosilva 1y ago
      Yes, and I would add my favorite hypothesis to the paradox, an anthropocentric assumption theory of self importance... or let's call it an anthropocentric bias: Humans tend to define intelligence, life, and communication based on our own structure -carbon-based biology, electromagnetic signaling, language, symbolic thought, etc. This narrows the scope of our search. We assume other civilizations want to communicate, would use similar media (radio, light, mathematics), and would send signals we could interpret. This ignores other potential modalities (quantum, neutrino, gravitational, exotic matter, etc.) or entirely non-signal-based forms of interaction. We may not even recognize signs of intelligent activity if they don't resemble our expectations, ie entire civilizations could exist in forms of computation or energy we can’t perceive. We assume ET intelligences are aligned with our timeframe or curiosity. Maybe they don’t care to communicate, see us as trivial, or operate on million-year attention spans. It may reflect less the silence of the cosmos and more the limits of our understanding, especially the assumption that we're capable of detecting or interpreting intelligence beyond Earth. A epistemic humility, or rather our lack of it.
      - esprehn 1y ago
        The counter argument is that even if civilizations exist with all the properties you described, given the vastness of space, there should be another civilization that pattern matches to us.
        ojosilva 1y ago
        Sure! All the hypothesis in the Fermi paradox deal ultimately with calibrating our expectations of making contact, not with denying the existence of "STEM-enabled" species like us yearning for an alien encounter.
      - andrewflnr 1y ago
        There's epistemic humility, then there's indulging in unfalsifiable fantasies in the name of not ruling anything out. > Humans tend to define intelligence, life, and communication based on our own structure -carbon-based biology, electromagnetic signaling, language, symbolic thought, etc. I would posit that none of these properties are coincidences, and are in fact likely to evolve convergently in most if not all circumstances hospitable to life. In particular I very much expect ET life to be carbon based; I don't believe there's a true viable alternative outside scifi (hint: silicon ain't it). > entire civilizations could exist in forms of computation or energy we can’t perceive. Could they? Really? There aren't that many gaps in the Standard Model. The aliens could be made of dark matter, I guess, and remain forever undetectable, but that's not to far off believing in invisible fairy kingdoms. And it still wouldn't explain why the baryonic sector is so devoid of detectable life. Ethereal undetectable aliens don't mean regular ones can't also exist. > Maybe they don’t care to communicate, see us as trivial, or operate on million-year attention spans. This one I'll grant (sort of: what's the evolutionary path toward such entities arising?), but it's still weird that we haven't seen any sign at all of them. These entities live on million-year timescales but have no visible effect on their surroundings? Why? And more importantly, why is that the only thing that happens? Because if it isn't the only thing, then the question remains of why can't we see anything else?
strictnein 1y ago
Systems we built in the 1970s were able to easily pass through this though. Which doesn't seem to indicate that it would make interstellar travel impossible.
- andrewflnr 1y ago
  Systems from the 1970s travel at, by interstellar standards, agonizingly slow speeds. The voyagers will be exposed to hard radiation for thousands of years before they get anywhere interesting. They will not survive.
  - strictnein 1y ago
    Not sure exactly why you're responding to me. The comment I was responding to was talking about the hot particles that would be encountered, and that their existence could preclude future interstellar missions. What level of "hard radiation" are they now getting bombarded by that we will be unable to shield systems from in far future interstellar space travel?
    - andrewflnr 1y ago
      I'm saying the Voyager probes don't make a counter example to interstellar travel being impossible. That's still very much an open question. We might be able to develop adequate shielding to protect spacecraft from radiation over mildly geologic timespans, but we might not. I'm certain it won't be as easy as you seem to think it is. (Unless you count slinging a dead pile of former computers through a distant star system as successful interstellar travel, but that's not what most people are interested in.)
      - mxkopy 1y ago
        Imagine if a dead pile of computers that wasn’t ours arrived in our solar system, I’d call that successful by some metric
  - deleted 1y ago
    [deleted]

jauntywundrkind 1y ago

Also sort of the plot of Solar Winds (1993, Epic MegaGames). https://en.wikipedia.org/wiki/Solar_Winds https://en.wikipedia.org/wiki/Solar_Winds

deleted 1y ago

[deleted]

TeaBrain 1y ago

It's not a new idea. The posted article is just about Voyager apparently observing the phenomena more closely. Voyager 1 had already reached the termination shock of the heliosphere in 2004 and Voyager 2 in 2007. The heliosphere containing a heliosheath, past the boundary of the termination shock, composed of compressed superhot solar winds had been hypothesized, due to the compression of the solar winds that begins at the termination shock. Reading the article, the wall is referring to the heliopause, which is the boundary past the heliosheath. Also, it looks like both voyagers traveled past this over a decade ago.