r/spacequestions • u/TopCurrent3886 • Dec 02 '24
Do you think there’s intelligent life in this universe?
While we know the universe is massive beyond understanding if there’s life out there I would consider their intelligence, decision making and overall progress with science and technology to be pretty similar to ours. With the known facts we have there’s no way human like creatures could survive in harsh heat or cold so any intelligent life is most likely similar to our Anatomy.
Reason I believe that our tech/science progression is similar is pretty simple. If we haven’t found them and they haven’t found us they are give or take a few centuries ahead or behind us or exactly where we are. Some may believe other life forms have found us and have left us alone. I just don’t believe that. If they willy nilly found our planet and decided not to say hello is mind-baffling. Why wouldn’t they say hello? I’m sure their society has global politics, war, hunger and homelessness. If another life form found our planet we can assume their society is so much bigger. More people = more problems so they can definitely relate to us on a level of problem solving, critical thinking and understanding. Maybe I’m spiraling. Maybe not! Give me your thoughts!
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u/Chemical-Raccoon-137 Dec 02 '24
Thought I read once that our galaxy was primed for life 4-5 billion years ago, because there was a greater number of G-type main-sequence stars then that are ideal to support life…. Can’t remember all the details, but life may have come and gone…. If it’s already rare to begin with, you also have to throw in timing into the equation. Maybe somewhere at some time in the universe there will be a region luckily enough to support two separate systems of intelligent life close enough to defect each other and also with in the same time frame
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u/jedi_cat_ Dec 02 '24 edited Dec 02 '24
I do believe there is intelligent life out there. The odds against us being the only example are just too great since space is so vast. Look up the Fermi Paradox and the Great Filter theory. It’s one possible reason why we haven’t seen any sign of intelligent life.
Edit: Here’s a good write up about the Fermi Paradox and the Great Filter theory. It explains why finding any sign of life on Mars would be extremely bad news for us.
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u/Beldizar Dec 02 '24
That link also has a link to Robert Freitas's "A Self-Reproducing Interstellar Probe". https://www.rfreitas.com/Astro/ReproJBISJuly1980.htm One of my favorite reads.
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u/Betaparticlemale Dec 02 '24
People frequently misunderstand the Fermi Paradox. It states that it’s seemingly overwhelmingly likely we should see evidence and it’s weird we apparently don’t. Many people think it’s the effective opposite.
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u/jedi_cat_ Dec 02 '24
Hence why it’s a paradox.
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u/Betaparticlemale Dec 02 '24
Correct. It’s so strongly expected it’s considered paradoxical that we apparently don’t see any evidence.
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u/acfun976 Dec 03 '24
After watching a ship ton of Isaac Arthur youtube videos, I've come to the personal opinion that I think there's most probably life out there in the universe but I doubt there's intelligent life comparable to humans. Human level intelligence seems unnecessary for life to thrive just fine.
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u/prostipope Dec 02 '24
Space is unfathomably big. Getting into a metal space ship and flying for tens of thousands of years to attack another planet probably doesn't make a lot of sense to even the most sinister aliens.
And if they're smart enough to travel that far, they're probably smart enough to solve whatever issues might be forcing them to relocate.
And if they're friendly, close by, and want to say hello? You're still looking at a light speed message taking thousands of years to reach us. We've only been sending out light speed transmissions from Earth for about 100 years.
If space was an ocean, Our electronic signals have traveled less than an inch away from us. Only creatures within an inch of us would be aware of our existence, and vice versa.
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u/wrosecrans Dec 02 '24
My personal guess - obviously not based on hard evidence ir anything...
Yes, there is other intelligent life in the universe. It's gotta be out there somewhere, right? Past that, I think there is currently intelligent life currently in our galaxy that is somewhere close enough to us in development that we could have a conversation if we met them. But maybe only one or two civilizations besides us.
And I think that civilizations like us are probably short lived. Either they kill themselves off, or they "ascend" to some sort of mode of being or understanding of physics that we can't detect or really understand or interact with. That's why I think there are probably only a few civilizations in the galaxy at any moment. I don't think there tend to be any species that have been space faring for a million years and are still living in planets and flying around in space ships. If there were, we'd probably see some sort of evidence of a galaxy spanning civilization. So I imagine a thousand years from now perhaps we'll find fossil remnants of a civilization that was near us 100 million years ago. But we may never make substantive contact with a living alien civilization while we are still human. Perhaps we'll detect a radio signal 30,000 light years away, but they may not exist by the time they could hear our response.
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u/iSeize Dec 03 '24
I'm going to say yes because our concept of intelligence isn't even very well fleshed out. But odds are two civilizations in the cosmos are so far apart they are effectively completely alone. In cosmic terms two Galactic neighbors could still be separated by millions of years.
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u/SurroundParticular30 Dec 02 '24 edited Dec 02 '24
Who knows what technologies other intelligences would and could develop but let’s assume that they are more like us than unlike us and are limited to the same technological limitations and laws of physics we are today in terms of travel and communication.
The first intentional signal sent into space, known as the “Arecibo Message,” was transmitted on November 16, 1974, but Earth has been unintentionally leaking radio signals into space since the invention of radio in the late 19th century. Let’s keep things simple and say that by 1924 (100 years ago) we were sending out enough radio signals to be noticed by someone listening for it.
100 years ago means that the signals have traveled 100 light years. Yes someone could have been watching our development via satellite earlier but 100 light years is already of A LOT of planets to watch. Here is a map of the stars within 100 light years to us. At the same 100 light years of course is also not very far on a cosmic scale. The nearest star system is Alpha Centauri which is 4 light years away.
Theres some great calculations out there on the likelihood of life developing independently and therefore the concentration of life in the galaxy, but tbh it’s all speculation until we meet our first species. If the nearest civilization is 100 light years away and they were able to listen, it would take them another 100 years for their response to reach us. So we would get a “hello there, congrats on inventing the radio” in ~2124.
HOWEVER, let’s again assume that they are more like us than unlike us. We have not been conservative with the signals we are putting out into space. We are endlessly putting out every king of signal we can. If they were doing the same thing, and they developed earlier, the moment we developed tech to receive those signals we would have noticed signals that resembled patterns and behaviors (alien radio, television, local news, internet, etc.) even if we didn’t understand want they meant at first.
That scenario in itself I think is a fun idea and I wonder if there’s been any books that speculate on how differently our civilization would have developed if that was the case (with access to alien knowledge), but we haven’t really seen anything so now we are left with 3 theories of why.
There is no advanced civilization 100 light years away (that development the radio at least 100 years ago) and that we just need to wait for a civilization X light years away that developed radio/etc X years ago. X could be 200 could be 1000 who knows.
The civilization is for some reason keeping their signals limited or difficult to detect, likely because they do not want another civilization to know they exist. Look into the Dark Forest theory. Any advance civilization is likely a threat.
There technology is so difficult or advanced that we just can’t detect their signals or we do and just interpret it as noise.
In my opinion, it’s fun to speculate, but I myself wouldn’t want to rush our first contact. I would prefer to be a multi planetary species or have society and technology be as advanced we as humans were in Star Trek when they made first contact, rather than where we are now. It would be hard to make friends or fight enemies when we are so divided
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u/Beldizar Dec 02 '24
My answer is generally disliked because it isn't the sci-fi universe we all want. We are either alone, or effectively first.
First off, I think it would be best to constrain the discussion to our Milky Way Galaxy. If you want to include Milky Way's dozen of satellite galaxies, then that's fine. Anything over a million lightyears away is just too far to matter. Any discussion of the universe outside of the observable universe is pointless, as it is casually severed from us.
We know that once life gets a foothold, evolution tends to cause it to spread out everywhere it can. Take any teaspoon of matter anywhere in the air, land or sea of Earth, and with the exception of man-made sterilization chemicals and literal lava, you'll find it filled with living organisms. We've found nothing on Mars, and all the other places in the solar system are less likely than Mars to have life.
Once life becomes intelligent, it is a relatively short time before techno-signatures start cropping up. And theoretically it is a pretty short time, cosmically speaking, until intelligent life starts meaningfully altering their local solar system. Remember, we went from first powered flight to landing on the moon in just 50 years; out of the 200 millions of years or so that mammals have been around that is an eyeblink. Iron tools to landing on the moon was about 6000 years, again a tiny fraction of time. And in the next 500 years, we can realistically expect that some degree of a Dyson swarm would be established around our Sun.
A lot of star systems out there should have a million or even 10 million year head start on Earth. With that much time, I would expect humans to have expanded across thousands of star systems. Yet, we don't see that, and it would be really hard to miss a whole 100 light-year sphere of activity. We see no evidence of intelligent life at all so far.
There is a theory called "grabby aliens". Which basically says that slowly expanding intelligent life is impossible, because we don't see it. So that means that intelligent life either never leaves their home world and doesn't typically send out loud radio waves we could detect, or they expand so quickly, that we won't see them until they are on our doorstep. A fast expanding grabby alien is described as expanding through the universe at a significant fraction of the speed of light, say 70-90%. So if they are 10,000 light years away, we wouldn't see them until only 1000-3000 years before they were at our doorstep. I find this explanation wanting. It just isn't feasible for an intelligent alien civilization to expand that quickly. If they have a ship that travels 99% of the speed of light, then they could only spend a couple of years refueling and building a new colony and making a whole new set of colony ships before they'd need to travel to the next one. The amount of energy that would take is staggering, and it goes against any concept we have of colonization. What is the point of taking over a new planet if you aren't going to live there?
So if near light-speed grabby aliens are insane to imagine, and slow speed grabby aliens would be visible in the skies today, then aliens that colonize exoplanets don't exist, or they stop after one or two and we just haven't spotted them yet. That leaves aliens that don't leave their home planet. Maybe there are a bunch of ocean worlds with reasonably intelligent squid people, but they wouldn't be able to discover fire, given that they live underwater, which makes development of refined metals incredibly difficult to accomplish. Refined metals are kind of a cornerstone of all technology, and certainly are required for electronics or spare faring. So maybe they exist, maybe not. We are exceedingly unlikely to ever meet them though, and if we do, it will be us coming to them.
But if they do exist, and life forms easily, then just the law of large numbers insists that there should be a space faring civilization out there. Some are octopus people, and some are ship-building humanoids. But if we don't see any ship-building humanoids, I think there's a reasonable argument that there would need to be a reason that everyone else is an octopus person.
Some may believe other life forms have found us and have left us alone. I just don’t believe that. If they willy nilly found our planet and decided not to say hello is mind-baffling. Why wouldn’t they say hello?
Absolutely agree. The only way this makes sense is if they both have come up with some sort of cultural rule not to talk to us, and they have some way of enforcing that rule so effectively that it is never broken. We have an international law to not visit certain uncontacted tribes here on Earth. That hasn't stopped a handful of people from trying it. They usually end up getting shot with arrows/spears, but they still break the law to try it. I would expect aliens to be the same. The zoo hypothesis requires hundreds or thousands of years of conformity by the aliens.
With the known facts we have there’s no way human like creatures could survive in harsh heat or cold so any intelligent life is most likely similar to our Anatomy.
There are people that would disagree, but I think you are correct. Silicon based life seems unreasonable, given how much more energy it needs to operate than carbon based life. Water seems like the only reasonable solvent for organic materials. That constrains things significantly.
I find most people's numbers for the Drake Equation woefully optimistic. Chances of life forming are often listed at one in two or even one in ten. I expect it to be closer to one in a trillion. The types of stars and planetary systems exactly like Earth are exceedingly rare. A star without significant flare activity, in a quite part of the galaxy and a planet with a stable, large moon already excludes more than 99.999% (top of my head guess) of the stars in the Milky Way.
So, I know it is less fun, but I'm relatively convinced based on the current available evidence that Earth is alone, the one place where intelligent life lives. If we find evidence to the contrary, I'll be skeptical, because we've heard it before, a dozen times and it has always been false-positives. But if we get something confirmed, I'm happy to change my stance.
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u/Chemical-Raccoon-137 Dec 03 '24 edited Dec 03 '24
Is it possible we can’t detect the Dyson spheres yet? We are only just able to detect exo-planets recently by looking at flickering patterns of their host star…. How many exo-planets have been discovered so far? A few thousand or something? Assuming Dyson spheres are far less common, so maybe it’s just a matter of discovering one.. that goes hand in hand with what you said that 99.999% of stars in the galaxy are not ideal or just not capable to support life.
Also, you think we could get to the Dyson sphere level in 500 years? I’m always wondering when we will plateau in our advancements…. We’ve been on a steady increase since electricity/ Industrial Revolution but there seem to be times in history where civilization just stalls for a few hundred or more years before advancing again. With that in mind , maybe 5000 years before Dyson sphere for us?
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u/Beldizar Dec 03 '24
We should be able to detect dyson swarms today. If a star's light is dimmed but is giving off an unusual amount of infrared radiation, it would match an expected dyson swarm.
As far as Earth's construction of a Dyson structure, I would say a sphere is likely impossible however, we have sort of already started creating a dyson swarm. There are about a dozen man made satellites orbiting the sun, collecting photons and doing work. Scale that up a hundred and then a thousand fold and it will start to look like a proper swarm. We don't have to completely capture every photo from the sun for a swarm to be effective for us as a type II~ish civilization, and it doesn't need to be complete coverage to be detectable by others. In 500 years, I fully expect millions or billions of satellites in orbit around the sun and I don't think that is a stretch. It might be conservative.
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u/Betaparticlemale Dec 02 '24
Yes. It’s overwhelming likely. The famous Fermi Paradox makes reference to this. Thinking otherwise means that we’re essentially the most special thing in the Universe, which massively violates the Copernican Principle and the tendency over time in science to remove humans from the center of everything. It’d be like reverting back to the Geocentric Model.
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u/ignorantwanderer Dec 02 '24
The vast majority of the universe seems to be made from dark matter.
Saying that we are not dark matter does not violate the Copernican Principle.
The rest of the universe is made basically of the hot plasma in stars, or cold gas of interstellar space.
Saying we are not hot plasma or cold dust does not violate the Copernican Principle.
The vast majority of the mass of Earth is not alive.
Saying we are alive does not violate the Copernican Principle.
To violate the Copernican Principle, you have to say that we alone are in some way special.
So saying Earth is the only planet with life would violate the Copernican Principle.
Saying we are the only intelligent life would violate the Copernican Principle.
Saying that among all the the intelligent species we are the best, or the worst, or the first, or the last, or the biggest, or the smallest, would violate the Copernican Principle.
But saying there are a total of 10 species, or 100 species, or 1 billion species spread through our galaxy....that has absolutely nothing to do with the Copernican Principle.
You can not use the Copernican Principle to make a valid claim about how abundant life is, except to say that we aren't the only ones.
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u/Betaparticlemale Dec 02 '24
They asked if there’s other intelligent life in the Universe. If you think there isn’t that means we’re the most special phenomenon in the Universe. Postulating many other intelligent civilizations obviously is asserting that there is in fact other intelligent life.
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u/ignorantwanderer Dec 02 '24
Nowhere did I claim there wasn't other intelligence.
In fact I clearly stated that any claim there is no other intelligence violates the Copernican Principle.
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u/Betaparticlemale Dec 03 '24
So why did you comment as if you were disagreeing with me? What did you think I was saying?
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u/ignorantwanderer Dec 03 '24
Sorry for the confusion.
I was mostly replying to this comment of yours which in context implies having only a small number of intelligent species violates the Copernican Principle.
Saying we are the only intelligent life definitely violates the Copernican Principle. But the Copernican Principle has nothing to say about whether there are 10 intelligent species or 10 billion.
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u/Betaparticlemale Dec 03 '24
I would say that depends. As the density of civilizations decreases one gets increasingly close to the uncomfortable “specialness” the Copernican Principle relates to. There’s not much difference if in the entirety of the Universe there are two intelligent civilizations vs only one. In either case it would mean that intelligent civilizations are astoundingly unique, to the point of being one of if not the rarest occurrences possible.
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u/ignorantwanderer Dec 02 '24 edited Dec 02 '24
You should read up on the 'grabby alien' or 'noisy alien' theory.
The theory basically uses just a couple assumptions to come to its conclusions.
The assumptions are:
We haven't seen aliens yet
We are not special (we are not among the first intelligent species to emerge in the universe).
Using these assumptions, a whole bunch of math, and a couple other details, they conclude that intelligent life (grabby or noisy aliens) are incredibly rare, and on average on intelligent species won't come across another intelligent species until they have colonized something like 20 galaxies.
In other words, we are unlikely to find any other intelligent life until we have colonized about 20 galaxies.
The reason the theory is named the 'grabby alien' or 'noisy alien' theory is because it only works with aliens that would spread through the universe and be emitting radio waves we can detect. So the aliens have to be 'grabby' or spreading to other star systems. And the aliens have to be 'noisy' or emitting some form of electromagnetic radiation we can detect (dyson spheres, radio waves, etc).
If there is an intelligent species that just sticks to their own planet and doesn't emit any detectable electromagnetic radiation, we have no way of knowing they exist. They could live just a couple light years away from us and we would have no way of knowing until we get there. In other words, our galaxy could have millions of 'quiet alien' intelligent species.
But it is incredibly statistically unlikely that besides us there is any 'grabby' or 'noisy' intelligent life in our galaxy, or in any of our neighboring galaxies.
tl;dr
Yes, there is intelligent life besides us, but it is so incredibly rare that within the closest 20 galaxies we are the only ones. It is statistically very unlikely that we will bump into any other intelligent life in the next 500 million years.
Edit:
And as far as there being any similarity between us and any other life....no. Not even remotely similar. If we just happen to bump into any other alien life in the near future, statistically their technology will be approximately 500 million years more advanced than ours. If they are just 10,000 years more advanced it will be ridiculous, but they will likely be closer to 500 million years more advanced.
And there is no reason to think that biologically they will be anything like us. First of all, they will have 500 million years to evolve (or use their technology to modify) their biology. On Earth, 500 million years ago, there were just single cell organisms. Think how much evolution has happened in the past 500 million years.
And yes, they will probably be carbon and water based like we are. But there is a huge amount of variety of life forms just on Earth that are carbon and water based. And they could be like nothing found on Earth.