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The speed of light essentially prohibits space travel. The fastest possible speed for any material object to travel at is incredibly slow compared to any meani

The speed of light essentially prohibits space travel. The fastest possible speed for any material object to travel at is incredibly slow compared to any meaningful distance. It is millenia just from the sun to the edge of our solar system, let alone to anything "near by". The universe is not the kind of place where living things can travel "between worlds". This is scifi -- and it is no coincidence UFO sightings peak in the era of Star Treck, and space races. P(All life is organic | All known chemistry) ~= Very High P(All intelligent organic life degrades) ~= Very High thef. P(Alien Life Lasts Long Enough To Travel | Above ) ~= Very Low Physics & Chemistry basically rule out alien contact. Once you insert these priors into your reasoning the "D - it's aliens!" becomes extraordinarily implausible. It's remarkable this author finds D-Aliens more likely than D-SecretSociety. The latter only requires plausible localised advancements in knowledge and conspiracy; the former requires believing everything we know about biochemistry and physics to be radically incorrect.

MobileVet 6y ago
While I agree with your assessment of known modes of travel, this also assumes we know everything. I believe it is a safe assumption that we do not. There are potential modes of travel via worm holes or similar inter-dimensional transits that could account for vast distances shrinking to zero without violating our known physics laws.
mrfusion 6y ago
You seem to ignore Von nuaman (sp) probes, generation ships, non carbon based life. And that’s before we consider that our understanding of physics may not be complete.
- mjburgess 6y ago
  I didn't ignore them. It may be clearer to write all probabilities above as being conditioned on "our best knowledge of the universe". P(All intelligent life is organic | Our best knowldge) =~ 1 Who knows the actual P(All intelligent life is organic). My point is that OP seems profoundly ignorant of "the facts of the matter" as our best theories describe them. Such facts make D-AnythingOtherThanAliens vastly more likely than D-Aliens. It is possible to "imagine" a world in which non-carbon-based life develops to an intelligent point (somehow with evolution...? adaption? ... organic growth...?)... And it is possible to Imagine they develop space ships, can travel near light speed and survive for billions of years without severe issues (again: how could an intelligent life develop which "thinks on small time scales" enough to build ships, but not be severely affected by having to live for billions of years?). And its possible to imagine such a species has been exploring the near infinite vastness of space for long enough to have found earth and contacted us in a bizarre series of ways that routinely have little in common. Etc. But this imagined scenario is based in exactly zero physics, chemistry, biochemistry or anything else. That such a novel can be written weighs nothing on whether we ought actual count it as a possibility.
  - mrfusion 6y ago
    I like your thinking but this still bothers me: > P(All intelligent life is organic | Our best knowldge) =~ 1 Even looking at ourselves, we are somewhat close to AI and it’s a reasonable belief that we’ll have something smarter than us within a few decades. Why are non organic aliens so unlikely to you?
    - lm28469 6y ago
      > we are somewhat close to AI and it’s a reasonable belief that we’ll have something smarter than us within a few decades. We've been saying that for the past 50 years or so now... We're always two years from self driving cars too. I wouldn't be so certain about AI, don't forget the 80/20 law, we got very good at pattern matching but we're faaaaar from general AI
    - mjburgess 6y ago
      I equally think P(Inorganic AI) is also vanishing low. What the ad companies have been selling, and researchers peacocking, isn't "AI". It's a system of manipulating electrical abacus beads to follow patterns of interest to human observers. Has very little to do with building systems that have relevant intrinsic properties. A digital computer does not weight more in virtue of simulating weight. A simulation is just an ape moving a bead along a wire to aid in its thinking. Simulations are cognitive games that enable us to reason more clearly. Nothing obtains any properties in virute of being a computer. A computer is just a type of gaming we are playing with another physical system. Intelligence is an instrinic property of really-existing physical systems; largely having to do with the ability to physical adapt on small time scales (ie., the brain grows differently in response to bodily-environmental dynamics). And on large time-scales (ie., evolution provides for the "right material" over >billion years via adaption -- which is an organic process). Only organic material has demonstrated the relevant short-time and long-time properties for intelligence. Games with electrical switches are apt to fool an ape looking at an LCD screen into thinking "there really is a virtual world in there!". But there isnt: it's an illusion. The LCD screen only appears to show it because we have rigged the beads to disturb the liquid crystal of the screen so as to present this illusion.
- Mediterraneo10 6y ago
  Generation ships may not be possible, at least for biological lifeforms. Kim Stanley Robinson wrote his novel Aurora in large part to argue this.
  - mrfusion 6y ago
    I’d be curious what the argument is. They would certainly be able to resupply raw materials if needed. Just plan a stop at a promising star system. Why wouldn’t a long lived nuclear power system provide the energy for food and life support? Beyond that, even five or ten generations is enough to get somewhere at .1C.
    - Mediterraneo10 6y ago
      I recommend reading the novel. The key line in it is “Life is a planetary phenomenon.” Basically, the argument is that at less than planetary scale, you would be confronted with things like waste products building up too quickly to sustain human life. For example, the generation starship struggles with an excess of salt (which in turn affects food production). The limited confines of the ship also produce deleterious effect on successive human generations akin to those found among species in isolated island ecosystems.
      - garbagetime 6y ago
        Maybe he had to make his argument into a novel because it isn't good enough to stand up to direct inspection. Deleterious effect of species on small islands are (a) maybe not always present? E.g. kakapo (b) due to factors which needn't be unaddressed in generational ships
        Mediterraneo10 6y ago
        He made his argument into a novel because he is a writer, novels are what he does. But he tends to write around the scientific ideas he has been reading and his work often serves as convenient summaries of those ideas for a broad audience – mentioning a KSR plot is standard fare on "news for nerds" sites like this one. Also, my post above intentionally says "akin to" and not "identical to".
TheAdamAndChe 6y ago
Humans only discovered the utility of carbon-based energy stores(oil) a couple hundred years ago, and already we've landed on the moon, harnessed nuclear fuel for various purposes, and purposefully fixed nitrogen en masse to allow our population to explode. We only recently connected several billion people on a common communication platform(internet) and discovered how to modify our genetic code in any arbitrary way we want. Do you honestly think that our current limitations will be the limitations of our species going forward? Imagine a species that has been undergoing such technological advancement for 10,000 years(a geologic blink of an eye) instead of 200. Even if we are fundamentally limited by the speed of light, stasis technologies and resistance to radiation exposure could be developed that make interstellar travel possible. Our closest star is only a few lightyears away.
garbagetime 6y ago
Your priors seem way off
T-A 6y ago
https://nautil.us/issue/29/scaling/why-alien-life-will-be-robotic https://nautil.us/issue/29/scaling/why-alien-life-will-be-ro...
lm28469 6y ago
> It is millenia just from the sun to the edge of our solar system ? We sent two probes in the 70s and they're already out of our solar system, they're definitely going waaaay slower than the speed of light https://www.bbc.com/news/science-environment-46502820 https://www.bbc.com/news/science-environment-46502820
- mjburgess 6y ago
  Depends how you define "solar system". I was taxing a maximal definition of the outermost region where the sun's gravity has a meaningful effect; but also, it wouldnt be 1000 light years, I agree. A more relevant number would just be distance to nearest system with planets of a relevant type. Or, likewise, the distance between this and the nearest galaxy (25k light years). Space is "big"; much much bigger than its maximal speed. Light is only fast "around here". Traversable space is tiny for everything; and minute for living things.
stevenhuang 6y ago
Your argument is invalid since you incorrectly assume that: - all known chemistry is all there is to know about chemistry, thus there is no basis to state all life must be organic - it's impossible biological systems can be made sufficiently error correcting, by technological or other means - conventional travel is the only form of space travel

MobileVet 6y ago

While I agree with your assessment of known modes of travel, this also assumes we know everything. I believe it is a safe assumption that we do not. There are potential modes of travel via worm holes or similar inter-dimensional transits that could account for vast distances shrinking to zero without violating our known physics laws.

mrfusion 6y ago

You seem to ignore Von nuaman (sp) probes, generation ships, non carbon based life. And that’s before we consider that our understanding of physics may not be complete.

mjburgess 6y ago
I didn't ignore them. It may be clearer to write all probabilities above as being conditioned on "our best knowledge of the universe". P(All intelligent life is organic | Our best knowldge) =~ 1 Who knows the actual P(All intelligent life is organic). My point is that OP seems profoundly ignorant of "the facts of the matter" as our best theories describe them. Such facts make D-AnythingOtherThanAliens vastly more likely than D-Aliens. It is possible to "imagine" a world in which non-carbon-based life develops to an intelligent point (somehow with evolution...? adaption? ... organic growth...?)... And it is possible to Imagine they develop space ships, can travel near light speed and survive for billions of years without severe issues (again: how could an intelligent life develop which "thinks on small time scales" enough to build ships, but not be severely affected by having to live for billions of years?). And its possible to imagine such a species has been exploring the near infinite vastness of space for long enough to have found earth and contacted us in a bizarre series of ways that routinely have little in common. Etc. But this imagined scenario is based in exactly zero physics, chemistry, biochemistry or anything else. That such a novel can be written weighs nothing on whether we ought actual count it as a possibility.
- mrfusion 6y ago
  I like your thinking but this still bothers me: > P(All intelligent life is organic | Our best knowldge) =~ 1 Even looking at ourselves, we are somewhat close to AI and it’s a reasonable belief that we’ll have something smarter than us within a few decades. Why are non organic aliens so unlikely to you?
  - lm28469 6y ago
    > we are somewhat close to AI and it’s a reasonable belief that we’ll have something smarter than us within a few decades. We've been saying that for the past 50 years or so now... We're always two years from self driving cars too. I wouldn't be so certain about AI, don't forget the 80/20 law, we got very good at pattern matching but we're faaaaar from general AI
  - mjburgess 6y ago
    I equally think P(Inorganic AI) is also vanishing low. What the ad companies have been selling, and researchers peacocking, isn't "AI". It's a system of manipulating electrical abacus beads to follow patterns of interest to human observers. Has very little to do with building systems that have relevant intrinsic properties. A digital computer does not weight more in virtue of simulating weight. A simulation is just an ape moving a bead along a wire to aid in its thinking. Simulations are cognitive games that enable us to reason more clearly. Nothing obtains any properties in virute of being a computer. A computer is just a type of gaming we are playing with another physical system. Intelligence is an instrinic property of really-existing physical systems; largely having to do with the ability to physical adapt on small time scales (ie., the brain grows differently in response to bodily-environmental dynamics). And on large time-scales (ie., evolution provides for the "right material" over >billion years via adaption -- which is an organic process). Only organic material has demonstrated the relevant short-time and long-time properties for intelligence. Games with electrical switches are apt to fool an ape looking at an LCD screen into thinking "there really is a virtual world in there!". But there isnt: it's an illusion. The LCD screen only appears to show it because we have rigged the beads to disturb the liquid crystal of the screen so as to present this illusion.
Mediterraneo10 6y ago
Generation ships may not be possible, at least for biological lifeforms. Kim Stanley Robinson wrote his novel Aurora in large part to argue this.
- mrfusion 6y ago
  I’d be curious what the argument is. They would certainly be able to resupply raw materials if needed. Just plan a stop at a promising star system. Why wouldn’t a long lived nuclear power system provide the energy for food and life support? Beyond that, even five or ten generations is enough to get somewhere at .1C.
  - Mediterraneo10 6y ago
    I recommend reading the novel. The key line in it is “Life is a planetary phenomenon.” Basically, the argument is that at less than planetary scale, you would be confronted with things like waste products building up too quickly to sustain human life. For example, the generation starship struggles with an excess of salt (which in turn affects food production). The limited confines of the ship also produce deleterious effect on successive human generations akin to those found among species in isolated island ecosystems.
    - garbagetime 6y ago
      Maybe he had to make his argument into a novel because it isn't good enough to stand up to direct inspection. Deleterious effect of species on small islands are (a) maybe not always present? E.g. kakapo (b) due to factors which needn't be unaddressed in generational ships
      - Mediterraneo10 6y ago
        He made his argument into a novel because he is a writer, novels are what he does. But he tends to write around the scientific ideas he has been reading and his work often serves as convenient summaries of those ideas for a broad audience – mentioning a KSR plot is standard fare on "news for nerds" sites like this one. Also, my post above intentionally says "akin to" and not "identical to".

TheAdamAndChe 6y ago

Humans only discovered the utility of carbon-based energy stores(oil) a couple hundred years ago, and already we've landed on the moon, harnessed nuclear fuel for various purposes, and purposefully fixed nitrogen en masse to allow our population to explode. We only recently connected several billion people on a common communication platform(internet) and discovered how to modify our genetic code in any arbitrary way we want. Do you honestly think that our current limitations will be the limitations of our species going forward? Imagine a species that has been undergoing such technological advancement for 10,000 years(a geologic blink of an eye) instead of 200. Even if we are fundamentally limited by the speed of light, stasis technologies and resistance to radiation exposure could be developed that make interstellar travel possible. Our closest star is only a few lightyears away.

garbagetime 6y ago

Your priors seem way off

T-A 6y ago

https://nautil.us/issue/29/scaling/why-alien-life-will-be-robotic https://nautil.us/issue/29/scaling/why-alien-life-will-be-ro...

lm28469 6y ago

> It is millenia just from the sun to the edge of our solar system ? We sent two probes in the 70s and they're already out of our solar system, they're definitely going waaaay slower than the speed of light https://www.bbc.com/news/science-environment-46502820 https://www.bbc.com/news/science-environment-46502820

mjburgess 6y ago
Depends how you define "solar system". I was taxing a maximal definition of the outermost region where the sun's gravity has a meaningful effect; but also, it wouldnt be 1000 light years, I agree. A more relevant number would just be distance to nearest system with planets of a relevant type. Or, likewise, the distance between this and the nearest galaxy (25k light years). Space is "big"; much much bigger than its maximal speed. Light is only fast "around here". Traversable space is tiny for everything; and minute for living things.

stevenhuang 6y ago

Your argument is invalid since you incorrectly assume that: - all known chemistry is all there is to know about chemistry, thus there is no basis to state all life must be organic - it's impossible biological systems can be made sufficiently error correcting, by technological or other means - conventional travel is the only form of space travel