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Discussion (20 Comments)Read Original on HackerNews
https://store.steampowered.com/app/3040110/Outsider/
Made for the HN crowd :)
They were going to upgrade us to a class B-1 civilization, but that was stopped after a second audit looked at the Politicians we have been electing....
“After they killed their first hundred thousand other people, why weren’t they arrested and jailed?”
“Err…”
“And why not arrest them after they stole billions from the public they were supposed to serve?”
“Umm…”
“I can understand voters making a mistake once… but repeatedly voting in the same autocrat?”
“Well…”
This is what I always thought was one of the major problems - unless an alien civilization is directly targeting Earth, we would never detect them. And our EM emissions are too weak to be detected by other aliens unless they stumble near us for some reason.
They found that airport radar systems, which sweep the skies for airplanes, send out a combined radio signal of 2×1015 watts. That’s enough for telescopes comparable to the Green Bank Telescope in West Virginia to pick up as far as 200 light-years away. [0]
200 ly is about 100k stars
[0]: https://earthsky.org/space/airport-radar-could-signal-earth-...
Seems that (r_d/(theta_e z))^2Pt_p ~ 100 hv (~100 photons at 3 GHz; a single 3GHz photon is about 2e-24 J) I'll drop this to 1 photon below.
Where
r_d = detector radius,
theta_e = diffraction angle of source,
z is detection distance,
P = 2e15 W (peak power of source, according to article) and t_p is pulse duration (say, ~5e-9 s).
Now theta_e ~ wavelength/(emitter radius), let's say the detector radius r_d ~ emitter radius = r ~ 3 meters for simplicity. Lambda = l = 3e8/3e9 m ~ 0.1 m) E_p = Pt_p ~ 2e155e-9 ~ 1e7 J (!)
(r^2/l)^2(1e7 J)/(1002e-24 J) = z^2, so z ~ \sqrt(100 m*(1e29)) ~ 3e15 m
But one light year is ~1e15 m. If I assume they have single-photon sensitivity in the microwave regime, then I can boost this result to ~30 ly. So about 1 order of magnitude less than their paper, but that is for a single photon of a single radar pulse. If you sum over many pulses from all the different radars that could be emitting over the integration time then, yeah, I guess 200 ly isn't ridiculous.
Curious what the cosmic microwave background is compared to this though...
interstellar expansion is going to be a huge hassle, at a minimum you are going to be mass constrained and require a long period of investment in fuel (such as antimatter production) during which your competitors that chose to stay in the solar system will gain an edge and may strike before you leave. there isn't going to be MAD in space once you no longer rely on your planet of origin for anything truly important.
we should actually be deeply worried about the space race, because the early adopters will be making nukes out there and may come back to yank up the ladders.
Getting from the Sun to Pluto takes a very long time you might give up and close your browser tab.
Many theories attempt to explain why we haven’t yet encountered extraterrestrial civilizations. One possibility is that, given the immense scale of the cosmos, intelligent life may exist but is simply too far away for contact. Another idea is that while life may arise on other planets, it rarely, if ever, evolves beyond primitive intelligence. Intelligence here defined as ability to understand the cosmos and even leave their own world.
But there is another, more sobering theory. It suggests that when life does evolve to the point of intelligence, it eventually develops technology so powerful that it inadvertently brings about its own destruction. Whether through war, environmental collapse, or uncontrollable advancements, these civilizations may end themselves before they have a chance to explore the universe, or be found by others. This concept just described is called The Great Filter. The Great Filter proposes that there is some critical barrier or stage in the evolution of intelligent life that is extremely hard to surpass. [a]
There's a Wikipedia page dedicated to nuclear close calls between the United States and the former Soviet Union, and also present Russia. [2]
Perhaps the most famous close call is the one involving Vasily Arkhipov during the Cuban Missile Crisis [3] [2]
“Man has dominated man to his injury.” — Ecclesiastes 8:9
The Great Filter need not be caused by the intelligent beings themselves and can be natural like the asteroid impact that wiped out the dinosaurs. It's said that asteroids of varying sizes crash into Earth every X million years.
There's a counter argument to the Fermi paradox that perhaps we are too primitive for advanced alien beings to bother with us. One of my internet friends put it like this -
"there are counter arguments to the fermi paradox; one of which hires the analogy of, iirc, a guy looking over at a group of insects/anthill/ worms. he doesn't go wondering whether those worms are sentient enough to meditate on his thoughts. he doesn't think to sit back to converse with them. hell, they wouldn't understand him even if he tried. the paradox only holds water on the assumption that such civilisation is within the scope of our comprehension. " [4]
But there's a counter to that counter argument.
Yes it's possible that we're too primitive for advanced civilizations to bother about. But even in the case of ants and humans, isn't it true that we sometimes try to interfere with their lives just to see how they'd react either for fun or just sheer curiousity?
Yes, it's true that we might not be able to comprehend alien species. After all, they evolved in worlds different from ours. But, any sufficiently advanced civilization would understand Mathematics. Mathematics is a universal language and for them to be scientifically advanced means they understand science. They could, if they desired, find a way to communicate with earthlings using the universal language - Science. Carl Sagan made this point in one of his books and I think it was Pale Blue Dot (highly recommended).
I've shared some of my thoughts about aliens on my blog posts which my comment here were from. [4] [5]
[1] https://www.joshworth.com/dev/pixelspace/pixelspace_solarsys...
[2] https://en.wikipedia.org/wiki/Nuclear_close_calls
[3] https://en.wikipedia.org/wiki/Vasily_Arkhipov
[4] https://www.rxjourney.net/extraterrestrial-intelligence-and-...
[5] https://www.rxjourney.net/mutually-assured-destruction
[a] https://en.wikipedia.org/wiki/Great_Filter
“What if we finally got visited by aliens but the most important event in or history was simply an intergalactic roadside picnic for the aliens?
They don’t even bother with us ants. They just pull over have some fun for a couple of hours and leave a mess behind…”
Thanks. Haha.
Given the complexity of the Periodic Table, molecules, DNA, &c can we agree that life is a low-probability event?
Previous paragraph omits the contextual perfection of our planet/solar system.
Seems fair to assert that we are a one-shot deal, until proven otherwise, here on Terra Fermi.
Given how quickly life started on Earth after Earth's formation, it seems like it isn't a low-probability event, but it still might be considering it's the only place we've found life (not that we've made a dent in our search of the cosmos for life).
"Wind back the tape of life to the early days of the Burgess Shale; let it play again from an identical starting point, and the chance becomes vanishingly small that anything like human intelligence would grace the replay." - Stephen Jay Gould.
> Previous paragraph omits the contextual perfection of our planet/solar system.
It's perfect because it's the world we grew up in.
The repeatable experiment would be another universe itself.
Cutting to the chase and declaring you the winner of the discussion.
Let say our civilization lasts for a million years. That's a blip.
We are searching across tens to hundreds of light-years for just our galactic neighborhood as well as cross time spans in the billions of years.
Life is rare, intelligent life is more rare, intelligent technological life is even more rare and inherently unstable, intelligent technological life maintaining political and cultural stability long enough to discover space travel is harder, the actual space travel is harder still, interstellar travel is harder still, the universe is vast, electromagnetic signals diminish into the CMB over time and distance, we may simply not see them, they may simply not see us, they may see us and simply not care. Everything, everywhere, all at once and sometimes you just get sucker-punched by an asteroid or a gamma ray burst or your sun just explodes.
The universe is the most complex and complicated thing there is, and there are more unknown unknowns than stars in the sky.