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I don't understand. I feel like I'm going crazy. If there was an identical civilization residing on an identical earth orbiting an identical sun at the distan

I don't understand. I feel like I'm going crazy. If there was an identical civilization residing on an identical earth orbiting an identical sun at the distance of our closest celestial neighbor, there is an exact and precise 0.0% chance that we would be able to detect them. We wouldn't be able to detect them optically or electromagnetically. There's no room for debate, we cannot resolve enough detail at that distance and our (and therefore their) highest-output EM emissions would fall below the noise floor. We probably wouldn't even be able to tell the composition of their atmosphere besides "uh there's a little methane, some oxygen, and some nitrogen in the extreme upper layers". It may be possible to send low data rate pulses between the two systems if high-gain high-power communications equipment is purposefully designed and installed on both planets and used to do so. Like two globe-spanning networks of high-power high-gain highly directional transmitters and receivers that are synced up to allow for continuous operation as both we and they rotate on a frequency ideal for punching through the magnetosphere, transiting space, and differentiating itself from the gigantic broadband emitters (the suns) adjacent to us. But neither we nor the hypothetical other-humans are doing any of that. But all of these supposedly smart people are like "where are the aliens? we're looking but they're not there!" We can't even detect ourselves at the distance of our nearest neighbor!

charcircuit 3y ago
>We wouldn't be able to detect them optically or electromagnetically. We can have have radio (electromagnetic) communication between the Earth and the Moon just fine.
- nikbackm 3y ago
  That's a fair bit closer.
  - charcircuit 3y ago
    It would be farther as the moon has a smaller radius than the second Earth that would be placed where the moon is.
- deleted 3y ago
  [deleted]
- Ekaros 3y ago
  Distance from Earth to Alpha Centauri is about 110 million times the distance to moon. And then remember inverse-square law. Which makes things quite a bit worse.
  - XorNot 3y ago
    The inverse square law only applies to omnidirectional antennas though: but stars have known positions, so any transmitter in the galaxy would be focused.
    - defrost 3y ago
      Even laser beams spread with distance, and these are vast distances. How do you imagine focusing "any transmitter in the galaxy" to converge at a distance of, say, 200 light years? Any rough calculations on the method, focusing array size?
  - charcircuit 3y ago
    Which is why Alpha Centauri is not our closest celestial neighbor as the moon is closer.
- pif 3y ago
  Light needs four years to travel from Earth to our nearest star, Proxima Centauri. Light need 1.3 seconds on average to travel from Earth to the Moon. Do you still think your comment makes any sense?
  - subtra3t 3y ago
    Perhaps their comment didn't possess the greatest technical merit but there is no need to be rude like that.
  - charcircuit 3y ago
    >Do you still think your comment makes any sense? Yes, because the nearest celestial neighbor is the moon and the nearest star is the sun. I don't see how Proxima Centauri is relevant here.
- snakeyjake 3y ago
  By celestial neighbor I meant proxima centauri. The moon is our celestial roommate.
A_D_E_P_T 3y ago
I agree with you. But here's how it goes: The universe is quite old. Civilizations could have arisen billions of years ago. It stands to reason that one or more of them would expand aggressively and attain a very high level of technological development, with Dyson Spheres and other artificial megastructures. This could include unnatural-looking star arrangements, technosignatures in stars, etc. The people who make these assumptions also assume, generally, that humanity will one day attain such a state. And in the not terribly distant future, at that. (Thousands rather than millions or billions of years.) Yet we don't see ANY evidence for any of this sort of thing. It's not that there are no civilizations at all, it's that, as far as we can tell, there are zero great star-faring civilizations -- no Rulers of the Cosmos. So why not? They've had billions of years. And any explanation (like "they're just not interested") has to apply universally, to ALL such civilizations. The most parsimonious explanations are: The Zoo ("they, being unfathomably more advanced than us, don't want us to see them,") The Great Filter ("something makes such life extraordinarily unlikely. This something -- the filter -- might be in our future.") The notion that ALL such civilizations are too wise to expand at this stage of the evolution of the cosmos ("the vacuum is too warm and it makes life/computation less efficient, so let's hibernate a few billion/trillion years until things cool down," or "we have attained enlightenment and don't need Dyson Spheres".) New Physics. ("We wouldn't even know them if we saw them. They might be able to convert waste heat to matter, etc.")
- bryanrasmussen 3y ago
  > This could include unnatural-looking star arrangements, technosignatures in stars, etc. If humans saw an unnatural-looking star arrangement I would expect them to expand a lot of energy trying to come up with an explanation as to why this star arrangement had formed naturally? Semi-Zoo: We, seeing something that could be explained as alien, will explain it in some other way.
  - 0xEF 3y ago
    I posit that out intrinsic drive to explain everything as though it's origin was from a thinking intelligence similar to our own is what causes us to misunderstand a great deal about our reality, and more specifically, about the possibility of alien intelligences. We do this, for example, with our pet dogs, ascribing anthropomorphic qualities to their behavior. While it may be true that a dog can experience emotion, they do not (likely) experience it the way we do. When it comes to these ideas about an alien civ traversing the cosmos (or staying home) we can only think about it in terms of the arguably tiny box that is our perspective. While this position has proven pretty useful to us so far, unless we learn to remove ourselves from the box, our explanations on the grander scale of galactic civilization and technologies beyond our understanding will be perpetually deficient. Insert Sagan's quote about advanced tech looking like magic here, I guess. I think we are getting there, though. We have some interesting thinkers in the world right now, and more surely to come with future generations. It just bothers me that this thread seems to be full of some really limited and unprovable ideas that are being presented as unassailable. So far our greatest explanation as to why we don't have any alien buddies is The Great Filter, and that's a about as structurally sound as wet tissue. Important to remember that we have a long, long way to go and it would be my hope that we achieve the ability to think like something other than ourselves.
mitthrowaway2 3y ago
"Our present technology is entirely adequate for both transmitting and receiving messages across immense interstellar distances. For example, if the 1,000-foot radio telescope at the Arecibo observatory in Puerto Rico were to transmit information at the rate of one it (binary digit) per second with a bandwidth of one hertz, the signal could be received by an identical radio telescope anywhere in the galaxy. By the same token, the Arecibo telescope could detect a similar signal transmitted from a distance hundreds of times greater than our estimate of 300 light-years to the nearest extraterrestrial civilization." - Carl Sagan and Frank Drake, "The Search for Extraterrestrial Intelligence" https://www.scientificamerican.com/article/the-search-for-extraterre/ https://www.scientificamerican.com/article/the-search-for-ex... (Of course, one could make the counterargument that we don't have Arecibo anymore...)
- snakeyjake 3y ago
  This is (was) true, but only if the distant end has an identical or better aricebo pointed at us… …several (or several thousand) years into the future. And even then tracking difficulties and the sheer vastness of space would make the chances of success near-zero. Due to having a fixed dish with only a movable antenna feed the available look angles of aricebo are limited. In all likelihood the aliens looking for us have a mega-aricebo in a random valley that is perfectly capable of receiving our signals but it is positioned one degree off-axis from the angle needed to receive us and they are as puzzled as we are as to why they are not hearing anything either.
JPLeRouzic 3y ago
> We wouldn't be able to detect them optically or electromagnetically Please could you provide a link that supports this assertion? We can detect gases in exoplanets?
jareklupinski 3y ago
my money is on Zoo, for the reason that: if you were surveying a planet, and the dominant species regularly engages in assymetrical warfare against every other species it encounters.... would you pay them a visit? we're stuck on a literal planet of Predators worse than a Zoo though, would be a Lab: were we made for a purpose by someone else to test a hypothesis? or even worse... what if we are the control group?

charcircuit 3y ago

>We wouldn't be able to detect them optically or electromagnetically. We can have have radio (electromagnetic) communication between the Earth and the Moon just fine.

nikbackm 3y ago
That's a fair bit closer.
- charcircuit 3y ago
  It would be farther as the moon has a smaller radius than the second Earth that would be placed where the moon is.
deleted 3y ago
[deleted]
Ekaros 3y ago
Distance from Earth to Alpha Centauri is about 110 million times the distance to moon. And then remember inverse-square law. Which makes things quite a bit worse.
- XorNot 3y ago
  The inverse square law only applies to omnidirectional antennas though: but stars have known positions, so any transmitter in the galaxy would be focused.
  - defrost 3y ago
    Even laser beams spread with distance, and these are vast distances. How do you imagine focusing "any transmitter in the galaxy" to converge at a distance of, say, 200 light years? Any rough calculations on the method, focusing array size?
- charcircuit 3y ago
  Which is why Alpha Centauri is not our closest celestial neighbor as the moon is closer.
pif 3y ago
Light needs four years to travel from Earth to our nearest star, Proxima Centauri. Light need 1.3 seconds on average to travel from Earth to the Moon. Do you still think your comment makes any sense?
- subtra3t 3y ago
  Perhaps their comment didn't possess the greatest technical merit but there is no need to be rude like that.
- charcircuit 3y ago
  >Do you still think your comment makes any sense? Yes, because the nearest celestial neighbor is the moon and the nearest star is the sun. I don't see how Proxima Centauri is relevant here.
snakeyjake 3y ago
By celestial neighbor I meant proxima centauri. The moon is our celestial roommate.

A_D_E_P_T 3y ago

I agree with you. But here's how it goes: The universe is quite old. Civilizations could have arisen billions of years ago. It stands to reason that one or more of them would expand aggressively and attain a very high level of technological development, with Dyson Spheres and other artificial megastructures. This could include unnatural-looking star arrangements, technosignatures in stars, etc. The people who make these assumptions also assume, generally, that humanity will one day attain such a state. And in the not terribly distant future, at that. (Thousands rather than millions or billions of years.) Yet we don't see ANY evidence for any of this sort of thing. It's not that there are no civilizations at all, it's that, as far as we can tell, there are zero great star-faring civilizations -- no Rulers of the Cosmos. So why not? They've had billions of years. And any explanation (like "they're just not interested") has to apply universally, to ALL such civilizations. The most parsimonious explanations are: The Zoo ("they, being unfathomably more advanced than us, don't want us to see them,") The Great Filter ("something makes such life extraordinarily unlikely. This something -- the filter -- might be in our future.") The notion that ALL such civilizations are too wise to expand at this stage of the evolution of the cosmos ("the vacuum is too warm and it makes life/computation less efficient, so let's hibernate a few billion/trillion years until things cool down," or "we have attained enlightenment and don't need Dyson Spheres".) New Physics. ("We wouldn't even know them if we saw them. They might be able to convert waste heat to matter, etc.")

bryanrasmussen 3y ago
> This could include unnatural-looking star arrangements, technosignatures in stars, etc. If humans saw an unnatural-looking star arrangement I would expect them to expand a lot of energy trying to come up with an explanation as to why this star arrangement had formed naturally? Semi-Zoo: We, seeing something that could be explained as alien, will explain it in some other way.
- 0xEF 3y ago
  I posit that out intrinsic drive to explain everything as though it's origin was from a thinking intelligence similar to our own is what causes us to misunderstand a great deal about our reality, and more specifically, about the possibility of alien intelligences. We do this, for example, with our pet dogs, ascribing anthropomorphic qualities to their behavior. While it may be true that a dog can experience emotion, they do not (likely) experience it the way we do. When it comes to these ideas about an alien civ traversing the cosmos (or staying home) we can only think about it in terms of the arguably tiny box that is our perspective. While this position has proven pretty useful to us so far, unless we learn to remove ourselves from the box, our explanations on the grander scale of galactic civilization and technologies beyond our understanding will be perpetually deficient. Insert Sagan's quote about advanced tech looking like magic here, I guess. I think we are getting there, though. We have some interesting thinkers in the world right now, and more surely to come with future generations. It just bothers me that this thread seems to be full of some really limited and unprovable ideas that are being presented as unassailable. So far our greatest explanation as to why we don't have any alien buddies is The Great Filter, and that's a about as structurally sound as wet tissue. Important to remember that we have a long, long way to go and it would be my hope that we achieve the ability to think like something other than ourselves.

mitthrowaway2 3y ago

"Our present technology is entirely adequate for both transmitting and receiving messages across immense interstellar distances. For example, if the 1,000-foot radio telescope at the Arecibo observatory in Puerto Rico were to transmit information at the rate of one it (binary digit) per second with a bandwidth of one hertz, the signal could be received by an identical radio telescope anywhere in the galaxy. By the same token, the Arecibo telescope could detect a similar signal transmitted from a distance hundreds of times greater than our estimate of 300 light-years to the nearest extraterrestrial civilization." - Carl Sagan and Frank Drake, "The Search for Extraterrestrial Intelligence" https://www.scientificamerican.com/article/the-search-for-extraterre/ https://www.scientificamerican.com/article/the-search-for-ex... (Of course, one could make the counterargument that we don't have Arecibo anymore...)

snakeyjake 3y ago
This is (was) true, but only if the distant end has an identical or better aricebo pointed at us… …several (or several thousand) years into the future. And even then tracking difficulties and the sheer vastness of space would make the chances of success near-zero. Due to having a fixed dish with only a movable antenna feed the available look angles of aricebo are limited. In all likelihood the aliens looking for us have a mega-aricebo in a random valley that is perfectly capable of receiving our signals but it is positioned one degree off-axis from the angle needed to receive us and they are as puzzled as we are as to why they are not hearing anything either.

JPLeRouzic 3y ago

> We wouldn't be able to detect them optically or electromagnetically Please could you provide a link that supports this assertion? We can detect gases in exoplanets?

jareklupinski 3y ago

my money is on Zoo, for the reason that: if you were surveying a planet, and the dominant species regularly engages in assymetrical warfare against every other species it encounters.... would you pay them a visit? we're stuck on a literal planet of Predators worse than a Zoo though, would be a Lab: were we made for a purpose by someone else to test a hypothesis? or even worse... what if we are the control group?