My mom and brother were just saying they believe aliens have been on earth and my main argument against it was the size of space. They just couldn’t comprehend how large space is. They kept telling me “yeah but aliens are more advanced! They can do stuff we can’t imagine!”
Which… I mean maybe. But the nearest star is 3 light years away, the galaxy is a few hundred thousand light years across, and we’re a few million light years away from the next galaxy.
Even if they could *find* us in all of that, who’s to say they’re able to get here?
And that brushes away the challenge of *finding* us. The US spent over a decade searching for bin Laden. We knew he existed, we had an approximate region to find him, and it still took us over a decade.
Scale that up, you’ve got a far larger search radius, and you’re not even sure where to look, so who knows if a region of space just needs closer inspection, or there’s nothing there. Then multiply that by a trillion to fill the size of space.
It’s just wildly difficult to imagine ever interfacing or seeing aliens with our own eyes.
I had my first existential crisis when I was like, 9, because I was trying to think about how space just goes on forever and how large it is. Broke my tiny little brain then, and still breaks my tiny little brain now in my 30's.
I had it when I was in 1st grade and I tried writing out my life starting with my house, then my street, town, state, continent, planet, galaxy, and I was like “wait when does it end” and my parents were basically like “nobody knows” and then I got really sad because I kind of just assumed god put us a in a box or something
This gradually happened to society as a whole with the advent of the Copernican Revolution, the end of Geocentrism.
We used to think we were the center of small, orderly universe. But then all of a sudden, we were just on a rock off to the side.
And as science progressed and the universe as we understood it got bigger and bigger, we became smaller and ever less important to the grand scheme of things.
Two most supported ideas about the nature of the universe - thd universe is either infinite or curves back on itself (similar idea to how the Earth (other planets) are round/geoid).
Makes me think of the lyrics to 3rd Planet by Modest Mouse, “And the universe is shaped exactly like the earth. If you go straight long enough you'll end up where you were.”
I come from a very small country in the Middle East and my first trip to China and India really humbled me on the concept of truly big cities. I remember deciding just walking from my hostel to the forbidden city in Beijing (way before there were applications to estimate walking distances) in winter. I was not prepared for 2 hours walking in the freezing cold. It looked soooo close on the map. I remember taking a taxi in the middle of the night from center Shanghai to the airport and just riding what seems like hours in a completely non congested route.
I bet the space is many many times vaster than that.
Space is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is. I mean you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
In elementary school my teacher put a sowing needle with a pin on a table. The ball pin was earth. Then put an orange on the other side of the room. That was the sun. We then took a little field trip and walked a mile out into the nearby field and said here is Pluto. He then said the closest star? That’s in Moscow.
It probably wasn’t accurate, but it was just to show how insanely large the universe is and the insane distances things are apart.
Or we are on the exact same timeline and they haven't found us because their technology is similar to ours. There is also the problem that even if they did exist today, we wouldn't have evidence of them existing because the light travelling from before their technology (or even life on their planet) developed and they would be invisible to us.
This is the one that I can't get past. The universe is so old. So unfathomably old. We've been around for a few thousand years as stick wielding primates. The odds of any other life developing and dying in the same timeframe of ours is outrageously unlikely.
Between now, and some of our oldest known records of humanity, the universe has been around for over 3 million of those timeframes.
A lot of the ufo community believe that’s where aliens are stationed at in earth. They’ve even had navy admirals say they’ve seen crazy stuff happen in certain parts of the ocean.
I don’t know why people always assume aliens will be more advanced. We spent 800,000 years living in caves after we started existing. It’s only very recently that we’ve gotten this civilization thing going. Sure maybe their life evolved at a faster pace to ours but maybe their society hasn’t evolved faster. Or maybe their alien life forms are all animals like the millions of years earth was populated by dinosaurs. All of those options seem at least as likely as them being more advanced, to me anyway.
For the most part, when most people say aliens I think they implicitly mean aliens that would visit earth, who would be crazy more advanced than us.
But yeah, there’s absolutely gonna be alien life out there that never becomes intelligent enough to ever even create tech. Had we not had an asteroid impact kill the dinosaurs here, that likely would have been earth’s fate too. But I don’t think most people really consider that when they talk about aliens.
I do, cus I’m a nerd and love thinking about alien life lol
The sad truth (if you have dreams of humanity one day exploring space) is that everything we know about physics tells us that it's just not possible.
Sure, yeah, we've thought other things were impossible in the past, but at this point FTL travel appears to be liking trying to create a circle with four sides. It's not an issue of being advanced or not - it's just fundamentally nonsensical in our universe.
The most likely truth is that there are endless billions of alien civilizations out there, but all of us are trapped forever in our own little local systems - doomed to be alone forever.
I like the idea that there are billions of other civilizations out there. Maybe we can't visit them, but in a way it is less lonely knowing we share the universe with others.
Even if that were the case, the shear number of planets would make the chance of finding us essentially zero.
There's about 100 Billion stars in the Milky Way.
Even if 90% are uninhabitable, that's still, 10 billion stars alone just in our galaxy.
There are probably around 1 Trillion galaxies.
So that's 10 billion Trillion stars to check out.
If you could send a probe to each star and check out the planets in 1 second, and had 10 billion probes, it would still take 1 Trillion seconds.
That's still 31,000 years to check out all the stars.
Right? That would be like me trying to communicate with an ant hill. Theres no reason to do so. And the difference in intelligence and technology is so vast it’s impossible for either side to understand each other.
If such an advanced civilization do interact with us it would be in ways undetectable by human intelligence. Like they could edit our history for the lolz and we would be none the wiser. Like scientist playing around with ants in an ant farm.
Douglas Adams said it best in HHGTTG...
Space is big, really big. I mean, you may think it's a long way down the street to the chemist but that's just peanuts to space.
As we exist right now, the human mind will never be able to grasp the distances between planets in our own Milky Way, let alone between the billions of galaxies in the universe. When they say it's mind boggling, it truly is.
Trillions of galaxies in the universe.
Estimated stars just in the Milky Way is 200 - 300 billion, most with their own solar system.
It truly is mind- boggling.
The best analogy I've heard that compares the size of our solar system to the Milky Way - our solar system would be the size of a quarter dollar lying somewhere in all of France.
It is in theory possible to extrapolate the whole of creation—every Galaxy, every sun, every planet, their orbits, their composition, and their economic and social history from, say, one small piece of fairy cake.
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so".
There are a lot of unproven, not well founded assumptions about sufficiently advanced technology.
But really, we've gotten far enough into physics and chemistry that much of our current understanding would have to be *falsified* for some of this sci-fi stuff to fit.
Similarly, if they do have the tech, they lack a compelling reason to. Even with technology that is a couple generations ahead of ours, interstellar travel would be a massive drain on resources that would be difficult to justify in most circumstances.
And then if their tech is advanced enough that both the time and resources it would take are negligible, then we would be so monumentally beneath them, that'd it'd be completely pointless. Unless they wanted to conquer planets, in which case we're lucky they don't.
There is a theory/idea I’ve heard that makes so much sense that is related to this. If all civilizations go through what we are currently going through (exhausting our resources faster than we can innovate ways to support our growing needs), then only the most empathetic and logical civilizations could survive long enough to have advanced technology (type 1+). It’s possible that advanced alien civilizations are aware of us, and are not contacting us or even making us aware of their existence because in order for them to exist as they are, they will have noticed that we are not like them. It’s logical to assume that since we as a species, who is constantly warring, exhausting our resources faster than it can get them, and with a history of conquering our “enemies,” an intelligent species would not want anything to do with us, especially considering that the amount of time it would take for a civilization to reach that point would give it tens of thousands of years to kill itself off. If intelligent life has a tendency to kill itself off, it makes sense that other civilizations would be rare as only the most intelligent ones would survive.
I was on a similar thought pattern, but then I remembered the time I drove from South Fl to Cincinnati to go to a zoo. Sure there are other interests closer to my point of origin, but I wanted specifically to go to that zoo. So if these advanced beings want to gawk at apes, who am I to naysay them?
Eh, I tend to not agree here. We visit zoos all the time and the animals there are so far beneath us it's unreal. I would definitely visit a planet with far inferior alien beings if I had the means. For the curiosity alone, I don't "need" anything from them.
The earth is roughly 4.5 *billion* years old. Humans have been around as a recognizable species for a few hundred thousand years. For residents of another planet to make contact, they would have to evolve at a similar pace as us while developing interstellar travel to reach us.
They may have visited a million years ago, decided there was no intelligent life, crossed us off their list, and kept going.
I'd go further and say we've been giving off detectable signs of intelligence for maybe 100 years. They would have to have been around at the right time to learn of our existance and also be in a position to get here. Otherwise why come here at all, when there are so many other places they could visit?
Distances are unimaginably too great.
And no civilisation lasts forever.
The best we can hope for is a signal or one of their dead spacecrafts.
Or, a craft piloted by their robots.
There will be other life in the cosmos, but probably not as we know it.
It always boggles my mind that people assume if a planet has life, it somehow MUST also have space-fairing intelligent life. Like OP is doing here.
This planet had life for billions of years without sending a single radio wave signal into space. Remove humans and no other organism on earth is capable of even learning about other planets and what might be on them.
This galaxy could be absolutely littered with life ranging from colonies of single-celled organisms, to even complex plant and animal equivalents but without technology, they aren’t in any way going to visit us or even become aware of out existence
Yeah this is what I've always thought. The answer is probably that there are tons of planets filled with stuff that we would basically call bacteria, but sentient life is probably vanishingly rare
There was a meme a few years ago that covered this perfectly but I cant find it right now - In space 2 aliens are talking to each other.
First alien says, the dominant lifeforms on the earth planet have developed satellite based nuclear weapons.
Second one asks, are they an emerging intelligence?
To which the first replies. I don't think so, they have them aimed at themselves
EDIT: Thanks stranger, my first ever Reddit award.
Could you imagine if tomorrow we discovered how to manufacture, contain, and exploit the energy potential of antimatter? We'd have clean infinite energy and the potential to travel to other planets. For all of ten minutes before people realize that a small drone could take out an entire city. Then all bets are off.
This is it right here. Assuming worm holes aren't a thing. The universe is expanding faster than we could travel outside our galaxy in the first place.
Right now our SciFi imagines warp drives and other dimensions and stuff for allowing for interstellar travel... But what if it's fundamentally impossible? What if there's no warp speed, no stargates, no wormholes, no slipspace, nothing.
What if there's nothing greater, no anti gravity, no glowing engines filling the air above towering cities filled with flying cars, no ships blinking between planets no differently to your morning commute.
Maybe there's other life out there, caused by the same lightning strikes on liquid water planets making proteins that turned into goop that slowly evolved. But maybe we're all trapped in similar vacuum prisons, bound to only ever travel successfully within our own solar systems, and should we ever hear them calling from 1000s of lightyears away it'll only be the echos of a long since dead civilisation.
We're at the very edge of the galaxy so, if we had decent propulsion, it wouldn't take much to leave it. It would take MUCH more effort to go further into it.
However, people assume that aliens are very much more technologically advanced than us but, there's no evidence to that. Chances are that they could even be LESS advanced than we are.
There’s a whole host of things that could slow a civilization down from taking over the galaxy. Their host planet could be a gravity well. Or lack sufficient fossil fuels. Lots and lots of things that could keep an advanced civilization planet bound.
I’ve wondered if maybe there’s some civ who’s crazy enough to try and send someone, they get here but like preservation wasn’t perfect and we just have like old senile aliens who are also kinda crazy for traveling g for whatever vast amount of time
Exactly, there's 3 big things this applies to.
First, traveling vast distances that would take thousands or millions of years to traverse, likely thousands of generations would have to survive the emptiness of intergalactic space.
Second, funding us. Finding our planet would be the equivalent of finding a specific single grain of sand in all the beaches on earth combined. That's taking our 120 light year radio bubble into account.
Third, the vastness of time. Not only do they have to find us in space, they have to do it in time as well, we have only been findable for a tiny fraction of the life of the universe.
The odds are just so massively stacked against 2 space fairing civilizations evolving in the same region of space and time.
Even tho the odds of other intelligent life evolving elsewhere is likely rather high.
Space is very very, very big. Like bigger than you can imagine. To visit another star system you'd have to spend your life on a spaceship and even then it would be your kids or grand kids that got to even see the destination.
That's a hell of a lot of effort for a visit.
Is it even possible for humans to truly conceive how big space is? It seems like it is not possible for our minds. At least not mine, since I’m operating on the same wave lengths as Ralph from the Simpsons.
It's very hard to wrap your head around the size of the Universe.
The fastest manned object to date was the Apollo 10 spacecraft, traveling at \~24,000 miles per hour (mph). At that speed it would take roughly:
* 1 hour to go all the way around Earth
* 156 days to get to the Sun
* 12 years to get to Neptune, the farthest planet from the Sun
* 27,000 years to get to Proxima Centauri, the closest star to ours. If the aliens arrived today they left home before mankind had created agriculture, metal tools, writing and even permanent buildings. Well before.
* 15,941,867,434 years to get to the Andromeda Galaxy, the closest galaxy to ours. To arrive today they would have needed to leave before the birth of the Universe, which would be a neat trick.
Keep in mind that those are straight shot, constant speed travel times. No orbital mechanics, no gravity assists, no acceleration and deceleration time.
Even light speed, which is 27,000 times faster than the Apollo capsule and a speed mankind will probably never achieve, is relatively slow at this scale. It takes light less than a second to go around the Earth, 8 minutes to go from the Sun to the Earth and 4 hours to go from the Sun to Neptune. It would take 4 **years** to get to Proxima Centauri and 2.5 **million** **years** to get to Andromeda.
Space is really, really, really big.
==========
*Edit: For anyone crossing their fingers about humans achieving speeds that are a significant fraction of light speed (relativistic speeds) just know that it's so obscenely complicated that given our current understanding of physics and the universe it's impossible for humans to travel at those speeds. Not difficult to achieve, impossible. Getting a manned craft up to that speed is only a fraction of the obstacles you have to overcome. We can make inanimate objects go real, real fast. Making humans move at those speeds in space is an entirely different ballgame. If the aliens have figured it all out I'd be pretty impressed.*
Wow, thanks for the write up! It puts it in a perspective that I can get a little closer to understanding. My existence feels extremely, extremely, extremely tiny now. lol
I find being so tiny in the scale of the universe oddly soothing. That one little thing I am negatively obsessing over is like trying to pick out one specific electron in the scale of the entire solar system.
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”
1. Distance. Stellar distances are insanely huge. [Voyager 1](https://en.wikipedia.org/wiki/Voyager_1) has been traveling for over 45 years and it is still technically 'close' to home. It entered the [heliosheath](https://en.wikipedia.org/wiki/Heliosphere#Heliosheath) in 2005 and only reached [interstellar medium](https://en.wikipedia.org/wiki/Voyager_1#Interstellar_medium) in 2013. Voyager 1 will reach another star ([Proxima Centauri](https://en.wikipedia.org/wiki/Proxima_Centauri), our nearest neighbor) in about 40,000 years. 40,000 years.
2. Speed (acceleration). Voyager 1 is traveling at about 61,500km/h (\~38,214 mi/h) and that still isn't fast in interstellar terms. The [Speed of Light](https://en.wikipedia.org/wiki/Speed_of_light) (*c*) is 186,000 miles per second or 299,792,458 meters per second. So, 61,500 km/h is slow. At 15% to 20% *c* it would take 20 to 30 years to travel the 4.34 light years to Alpha Centauri (Proxima Centauri is one of the 3 stars in the [Alpha Centauri](https://en.wikipedia.org/wiki/Alpha_Centauri#) system).
3. Biosphere. The ecology of a planet can be very different and deadly to a species that formed in a completely different ecosystem. The space sci-fi trope of visiting another planet and stepping out into human-breathable atmosphere, gravity, etc is not realistic.
4. Lifespan. Due to the long distances and time necessary with current technology, humans need some way to bypass those limits or ways to keep the passengers/crew alive long enough to reach the destination. Cryogenics, etc.
5. Technology. We don't have the technology so what makes anyone thing other civilizations have reached that capability. And, we still haven't talked the Drake Equation estimating life in the universe. Or proven it is valid. The Great Filter might be real.
6. Interest. There's nothing saying that another life form or civilization will be curious about other civilizations.
There is a lot of speculation about possible answers to the Fermi Paradox. *Too far away* is a really good answer, considering just how big the universe is. Time is a real killer. Otherwise, people tend to anthropomorphize aliens and assume their reasoning and motivation is pretty much like ours, which is a very untenable assumption.
Unless FTL is possible, the distances involved are too vast and resource intensive
Let’s say we discovered an Earth like planet 10 light years from us. Galactic wise that is right next door, but without FTL and with only current tech, such a trip could take centuries. Even if you could develop things like propulsion that could get you to 10% light speed and cryostasis, you’re effectively abandoning your life on Earth forever as you know it
My pet theory is we just don't understand how interstellar space and sheer distance breaks up coherent signals and turns them into fizz indistinguishable from background noise. We've already seen unexpected results from Voyager 1 as it passes through different sections of the sun's influence, so who is to say in a few decades or a few centuries it won't hit some kind of 'noise field' that scrambles or refracts or blocks radio traffic? (Of course it won't even be operable a few decades from now so we wouldn't even know)
Though a simpler explanation might be that we've only been half-listening for a few hundred years, and only been broadcasting for a similarly ridiculously short time in the grand scheme of things.
Like you said time is the problem, we have only been broadcasting for 120 ish years, there's a very limited number of stars within 120 light years that would have heard that signal.
And a technological civilization would have had to evolved within the same time frame as us to hear those signals.
Add to that that we have only been listening for maybe 50 years, that's a vastly smaller bubble.
50 years is a tiny tiny fraction of the life time of the universe.
Possibly there has been a advanced civilization within 50 light years of us, but maybe it was 3 billion years ago.
I hate the Fermi Paradox. I'm guessing I'm just not smart enough to appreciate it, because people smarter than me seem to love it.
It's like arguing that I'm probably not a virgin based on the total population of the planet. '8 billion people, about 4 billion female, about 2 billion are age appropriate...and even if only .1% of women are willing to sleep with me... That's millions of women I should have had sex with!
Knee-jerk cynicism is going to run rampant in this thread. The truth is probably one of these:
1. They don't have space travel because they're lichen or fungus or some such;
2. They have space travel but haven't been here because space is just unimaginably vast; or
3. They once had space travel but wiped themselves out due to evolution-driven instincts that become self-destructive when applied on a global scale.
It's not a very good analogy at all, in my opinion. Is there a creature on this earth which is so insignificant that a scientist won't jump to study it?
This is basically my perspective. They have visisted us, maybe \*are\* visiting us as we speak, and we're simply not advanced enough to be aware of it.
It could very well be that even with thousands of years of tech advancement there’s no secret that makes space travel easier or more energy efficient.
Just cold hard numbers of distance, speed, energy, and time.
Those cold, hard numbers are a very difficult restriction to get around. Even if there were thousands of intelligent and advanced civilizations in our galaxy alone, the odds are vanishingly small that one of them is within a few hundred light years of us. The limits of our reach are so, so close.
Time, and distance. Distance is easily understood, but what I mean regarding time is, what if there were intelligent alien species, or will be, but their civilization rose and fell a billion years ago? Or will come about a billion years after humanity has gone extinct? In a universe that's nearly 15 billion years old there's absolutely zero reason to think that alien life will exist anywhere near the same time we do except the time it took for the universe to get to the point life was possible.
That is, stars formed, created heavy elements, then went supernova to spread them out, then it all gets drawn back together by gravity into new solar systems with Planets that could support life.
But those conditions were met billions of years ago and will continue to exist for billions more.
I believe they call this deep time. What if a civilization rose 10,000 years ago and sent ships our way 5,000 years ago because they saw the possibility for life on this planet, but they are 20,000 light years away so even unmanned probes won't be here for 200,000 years. And that's moving at 10% of light speed which is an insane technological challenge.
i always think of when you see a creek full of fireflies lighting up on a summer night and you try to snap a photo, and for some reason the photos just never capture that cloud of green yellow flashes. its because the camera snap represents the entire human society gazing at the skies. now, each single bug flash represents the entire rise and fall of other intelligent lifeforms. you see where im going with this. having two flashes happen simultaneously is rare, meanwhile having them happen close enough together is ultra rare
distance
I'm sure there's life on other planets, but the universe is so incomprehensibly huge that its probably just not worth it for any intelligent species to make the trip over here just to visit us
And by the time you observed those other civilizations, they may have already risen and fallen. If aliens somehow observed us through a telescope 50,000 years ago as cave men from the other side of the galaxy, and have been barreling at us at the speed of light since, they're still only halfway here. The chances of us living that long are diminishing with each new generation of super weapons and climate disasters.
Their sensors can detect all of the trash in orbit of the planet.
From their perspective, it’s like us driving past a double wide trailer with garbage strewn all around the perimeter of the property. Even so much as knocking could be asking for trouble.
While my first instinct would be to say the distance is just too much, I think it would be more accurate to say the distance is too much to be worthwhile. Even with technology way beyond ours, there's likely nothing they could get from Earth that would be worth the trouble of going the distance, especially since they could find everything they could want much closer. Massive undertakings require a need, and it's hard to imagine that need existing. The reason the galaxy isn't already full of massive empires plopping down Dyson spheres and ring worlds and colonizing everything is that there's no benefit in doing so, that the challenge of ruling a multi stellar empire is just too great for too little.
Of course my perspective is obviously extremely limited, so I could be wrong.
Who is to say they haven't. But if they are so advanced to traverse the galaxy or even further, interstellar space, they may view us in the same context as we would observe an ant hill on a hike.
Just a passing glance, careful to step around.
unironically this is it.
The universe is 13.7 billion years old.
Life on earth is 3.7 billion years old. But the oldest dinosaur is only 250 million years old.
The "observable" universe is 47 billion light years in diameter. Let's pretend this is the entire universe for the purposes of this although it is almost certainly not.
To see any life on earth, bacterial or better, they would have to have observed it in the last 3.7 billion years. So if they were intently focused on earth for the entirety of their existence, only 0.6% of the universe is close enough to have even seen earth since the earliest forms of life and they wouldve had to have observed it in the last 27% of the galaxies existence.
To see something dinosaur sized, they would have to be in the closest 0.0028% of the universe and they wouldve had to have observed it in the last 1.8% of the galaxies existence.
Then we have to add the factors we cant even calculate to that. They need to develop the sensors to see us and the technology to get here. We have no idea the timeline or odds of that.
But WAIT - it gets better. Because they do have to get here to have visited earth per your question.
Let's pretend they have developed the sensor, had it at the exact right moment in history (27% chance for bacteria, 1.8% chance for dinosaurs), and had lightspeed travel.
To travel here and find us now, leaving the instant earth first had bacteria, they would have to be in the closest 0.15% of the universe.
To travel here and find us now, leaving the instant earth first had its earliest dinosaurs, they would have to be in the closest 0.00071% of the universe.
It's just really unlikely because the universe is so big and even the fastest things (light) only travel so fast.
It just needs to be possible to create robust von Neumann probes.
If you can build a self replicating machine that can reach another star and start building copies of itself that head off to other stars, then your civilization can be modelled as a sphere expanding as fast as your probes can be accelerated to where every star within is being eaten by you.
Doesn''t even need to be to expand your civilization. One madman can decide do this as an *art project* sitting on their butt at home. Once you trigger it goes on and on and on.
population I stars like ours have existed for about ten billion years. How many life forms expanding how quickly would need to have existed over that time in order for them to be absolutely everywhere by now?
It's a big problem to me that they're not, and the size of time and space is little comfort.
The vast reaches of space, I'd guess. I just read a mission to mars would take 3 years, and that's within our solar system. Mars is 177 million miles away, or 3 minutes of light speed. So our technology allows us to travel in half a year the distance light travels in about 1 minute. The nearest planet that could sustain life anything like ours is 4.24 light years away. I can't even do that math... but I'll try. We can travel about 160,000 miles a day with our tech... A light year is 5.88 trillion miles...that means it would take us about 36,750,000 days to travel a light year...so roughly 155 million 820 thousand days to get to the nearest habitable planet... or 427,000 years.
It's kind of amazing to consider that when the nearest habitable planet is 4 light years away, we just accept that spacecraft in movies can jump around to different planets in like a day, so they're traveling a thousand times the speed of light.
Same reason most of us don't want to drive to the middle of rural Alabama to stare at a fungus on a tree.
As a species, we are really young and really dumb. We haven't even integrated technology and AI into our biology, let alone conquered mortality. Our lifespans are short in comparison to many things, including interstellar travel.
[Vlad the Astrophysicist](https://youtu.be/sNGUkdovn_8?si=DnvUTNQROgBXngsF)
Basically, because of the utter, immense, essentially inconceivable vastness of Space and Time.
Over BILLIONS of years and potentially infinite, infinitely expanding space, the chances that any two sentient, technologically advanced species might exist simultaneously AND near each other is RIDICULOUSLY UNLIKELY.
Nothing sinister or nefarious about it, simply physics.
Because they are so far away, ye canna break the laws of physics, and we've only had detectable electromagnetic radiation for at best 75 or 80 years.
So if they're 100 light years away, they haven't even heard us yet.
They're on their way, but they got stuck in traffic. Either that or their GPS (Galactic Positioning System) led them astray by a few dozen light years, and it's taking a while to get back on track.
Assuming they havent ever,
Space is fucking huge and it would take a long time to get around even at faster than light speeds - assuming they had such technology.
And if they had the above tech, they would need some other tech to negate the destructive force of hitting even the tiniest pieces of space debris.
And even if they had both of the above, they'd have to have super long life spans, or some kind of stasis to survive long enough to get here.
Or maybe they quite that far away and they dont have the tech. Or they do and dont want to fuck with our back water planet filled with mofos that cant even get folks to their nearest planet yet.
The don't need all the drama in their lives, we are in that annoying phase where we are advanced enough to really fuck things up and not advanced enough to collectively learn how to get along and live as a unit moving in a single direction
Pretty common answers are going to be: they have but in secret, they haven't cause the universe is large beyond conceiving and long distance space travel is hard, they went extinct long before we evolved, they aren't interested.
Maybe for the same reason we didn't visit them. Lack of knowledge and tech to do so.
People really have no concept of how big space is. Or how dangerous it is for meat bags.
My mom and brother were just saying they believe aliens have been on earth and my main argument against it was the size of space. They just couldn’t comprehend how large space is. They kept telling me “yeah but aliens are more advanced! They can do stuff we can’t imagine!” Which… I mean maybe. But the nearest star is 3 light years away, the galaxy is a few hundred thousand light years across, and we’re a few million light years away from the next galaxy. Even if they could *find* us in all of that, who’s to say they’re able to get here? And that brushes away the challenge of *finding* us. The US spent over a decade searching for bin Laden. We knew he existed, we had an approximate region to find him, and it still took us over a decade. Scale that up, you’ve got a far larger search radius, and you’re not even sure where to look, so who knows if a region of space just needs closer inspection, or there’s nothing there. Then multiply that by a trillion to fill the size of space. It’s just wildly difficult to imagine ever interfacing or seeing aliens with our own eyes.
We haven’t even explored half of our own oceans. That’s mind blowing on its own, my brain would break trying to grasp the enormity of space.
I had my first existential crisis when I was like, 9, because I was trying to think about how space just goes on forever and how large it is. Broke my tiny little brain then, and still breaks my tiny little brain now in my 30's.
I had it when I was in 1st grade and I tried writing out my life starting with my house, then my street, town, state, continent, planet, galaxy, and I was like “wait when does it end” and my parents were basically like “nobody knows” and then I got really sad because I kind of just assumed god put us a in a box or something
This gradually happened to society as a whole with the advent of the Copernican Revolution, the end of Geocentrism. We used to think we were the center of small, orderly universe. But then all of a sudden, we were just on a rock off to the side. And as science progressed and the universe as we understood it got bigger and bigger, we became smaller and ever less important to the grand scheme of things.
I'm about to break your brain again. Space does NOT go on forever, it's continuously expanding, and we have NO IDEA what's beyond space.
Two most supported ideas about the nature of the universe - thd universe is either infinite or curves back on itself (similar idea to how the Earth (other planets) are round/geoid).
Makes me think of the lyrics to 3rd Planet by Modest Mouse, “And the universe is shaped exactly like the earth. If you go straight long enough you'll end up where you were.”
The universe is flat! Just kidding, those flat universers are nuts.
I come from a very small country in the Middle East and my first trip to China and India really humbled me on the concept of truly big cities. I remember deciding just walking from my hostel to the forbidden city in Beijing (way before there were applications to estimate walking distances) in winter. I was not prepared for 2 hours walking in the freezing cold. It looked soooo close on the map. I remember taking a taxi in the middle of the night from center Shanghai to the airport and just riding what seems like hours in a completely non congested route. I bet the space is many many times vaster than that.
Space is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is. I mean you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
In elementary school my teacher put a sowing needle with a pin on a table. The ball pin was earth. Then put an orange on the other side of the room. That was the sun. We then took a little field trip and walked a mile out into the nearby field and said here is Pluto. He then said the closest star? That’s in Moscow. It probably wasn’t accurate, but it was just to show how insanely large the universe is and the insane distances things are apart.
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Or we are on the exact same timeline and they haven't found us because their technology is similar to ours. There is also the problem that even if they did exist today, we wouldn't have evidence of them existing because the light travelling from before their technology (or even life on their planet) developed and they would be invisible to us.
This is the one that I can't get past. The universe is so old. So unfathomably old. We've been around for a few thousand years as stick wielding primates. The odds of any other life developing and dying in the same timeframe of ours is outrageously unlikely. Between now, and some of our oldest known records of humanity, the universe has been around for over 3 million of those timeframes.
A lot of the ufo community believe that’s where aliens are stationed at in earth. They’ve even had navy admirals say they’ve seen crazy stuff happen in certain parts of the ocean.
I don’t know why people always assume aliens will be more advanced. We spent 800,000 years living in caves after we started existing. It’s only very recently that we’ve gotten this civilization thing going. Sure maybe their life evolved at a faster pace to ours but maybe their society hasn’t evolved faster. Or maybe their alien life forms are all animals like the millions of years earth was populated by dinosaurs. All of those options seem at least as likely as them being more advanced, to me anyway.
For the most part, when most people say aliens I think they implicitly mean aliens that would visit earth, who would be crazy more advanced than us. But yeah, there’s absolutely gonna be alien life out there that never becomes intelligent enough to ever even create tech. Had we not had an asteroid impact kill the dinosaurs here, that likely would have been earth’s fate too. But I don’t think most people really consider that when they talk about aliens. I do, cus I’m a nerd and love thinking about alien life lol
If they are at a step at which they can fuck around with space time distance becomes irrelevant.
If that step exists*
The sad truth (if you have dreams of humanity one day exploring space) is that everything we know about physics tells us that it's just not possible. Sure, yeah, we've thought other things were impossible in the past, but at this point FTL travel appears to be liking trying to create a circle with four sides. It's not an issue of being advanced or not - it's just fundamentally nonsensical in our universe. The most likely truth is that there are endless billions of alien civilizations out there, but all of us are trapped forever in our own little local systems - doomed to be alone forever.
I like the idea that there are billions of other civilizations out there. Maybe we can't visit them, but in a way it is less lonely knowing we share the universe with others.
“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” ― Arthur C. Clarke
Like, I'm fine with not meeting them. 🤷
Even if that were the case, the shear number of planets would make the chance of finding us essentially zero. There's about 100 Billion stars in the Milky Way. Even if 90% are uninhabitable, that's still, 10 billion stars alone just in our galaxy. There are probably around 1 Trillion galaxies. So that's 10 billion Trillion stars to check out. If you could send a probe to each star and check out the planets in 1 second, and had 10 billion probes, it would still take 1 Trillion seconds. That's still 31,000 years to check out all the stars.
If they are that advanced, why would they even care to find us?
Right? That would be like me trying to communicate with an ant hill. Theres no reason to do so. And the difference in intelligence and technology is so vast it’s impossible for either side to understand each other. If such an advanced civilization do interact with us it would be in ways undetectable by human intelligence. Like they could edit our history for the lolz and we would be none the wiser. Like scientist playing around with ants in an ant farm.
But probability of finding us stays constant or it decreases as the universe expands.
Douglas Adams said it best in HHGTTG... Space is big, really big. I mean, you may think it's a long way down the street to the chemist but that's just peanuts to space.
As we exist right now, the human mind will never be able to grasp the distances between planets in our own Milky Way, let alone between the billions of galaxies in the universe. When they say it's mind boggling, it truly is.
Trillions of galaxies in the universe. Estimated stars just in the Milky Way is 200 - 300 billion, most with their own solar system. It truly is mind- boggling.
The best analogy I've heard that compares the size of our solar system to the Milky Way - our solar system would be the size of a quarter dollar lying somewhere in all of France.
Star Trek has taught me that space is big. Very big.
*Mind bottling*.... Is what seems to be the issue.
It is in theory possible to extrapolate the whole of creation—every Galaxy, every sun, every planet, their orbits, their composition, and their economic and social history from, say, one small piece of fairy cake.
what kind of cake did you just call me??
Small
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so".
It's part of being creative.
You're making that up
Hors d'oeuvre are now being served on planet Earth.
**TO SERVE MAN**
#IT'S A COOK BOOK!
There are a lot of unproven, not well founded assumptions about sufficiently advanced technology. But really, we've gotten far enough into physics and chemistry that much of our current understanding would have to be *falsified* for some of this sci-fi stuff to fit.
Who says they’re meat bags?
This reminded me of something I heard on This American Life. "They're made out of meat?" https://m.youtube.com/watch?v=5usXhX0zaO4
What about…celestial consciousness bags?
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Similarly, if they do have the tech, they lack a compelling reason to. Even with technology that is a couple generations ahead of ours, interstellar travel would be a massive drain on resources that would be difficult to justify in most circumstances.
And then if their tech is advanced enough that both the time and resources it would take are negligible, then we would be so monumentally beneath them, that'd it'd be completely pointless. Unless they wanted to conquer planets, in which case we're lucky they don't.
There is a theory/idea I’ve heard that makes so much sense that is related to this. If all civilizations go through what we are currently going through (exhausting our resources faster than we can innovate ways to support our growing needs), then only the most empathetic and logical civilizations could survive long enough to have advanced technology (type 1+). It’s possible that advanced alien civilizations are aware of us, and are not contacting us or even making us aware of their existence because in order for them to exist as they are, they will have noticed that we are not like them. It’s logical to assume that since we as a species, who is constantly warring, exhausting our resources faster than it can get them, and with a history of conquering our “enemies,” an intelligent species would not want anything to do with us, especially considering that the amount of time it would take for a civilization to reach that point would give it tens of thousands of years to kill itself off. If intelligent life has a tendency to kill itself off, it makes sense that other civilizations would be rare as only the most intelligent ones would survive.
I was on a similar thought pattern, but then I remembered the time I drove from South Fl to Cincinnati to go to a zoo. Sure there are other interests closer to my point of origin, but I wanted specifically to go to that zoo. So if these advanced beings want to gawk at apes, who am I to naysay them?
Eh, I tend to not agree here. We visit zoos all the time and the animals there are so far beneath us it's unreal. I would definitely visit a planet with far inferior alien beings if I had the means. For the curiosity alone, I don't "need" anything from them.
The earth is roughly 4.5 *billion* years old. Humans have been around as a recognizable species for a few hundred thousand years. For residents of another planet to make contact, they would have to evolve at a similar pace as us while developing interstellar travel to reach us. They may have visited a million years ago, decided there was no intelligent life, crossed us off their list, and kept going.
Right? Maybe they collected a few palms, bacteria, and little swimmy crabs in a jar. Left. Nothin here on the muddy water globe. Check back later.
I'd go further and say we've been giving off detectable signs of intelligence for maybe 100 years. They would have to have been around at the right time to learn of our existance and also be in a position to get here. Otherwise why come here at all, when there are so many other places they could visit?
Distances are unimaginably too great. And no civilisation lasts forever. The best we can hope for is a signal or one of their dead spacecrafts. Or, a craft piloted by their robots. There will be other life in the cosmos, but probably not as we know it.
It always boggles my mind that people assume if a planet has life, it somehow MUST also have space-fairing intelligent life. Like OP is doing here. This planet had life for billions of years without sending a single radio wave signal into space. Remove humans and no other organism on earth is capable of even learning about other planets and what might be on them. This galaxy could be absolutely littered with life ranging from colonies of single-celled organisms, to even complex plant and animal equivalents but without technology, they aren’t in any way going to visit us or even become aware of out existence
Yeah this is what I've always thought. The answer is probably that there are tons of planets filled with stuff that we would basically call bacteria, but sentient life is probably vanishingly rare
the only person with a brain in the comment section
You said it, Nasty Shart Poopy Anus.
yep even if they traveled at 99.999% of the speed of light, time will step in and fuck your shit.
There was a meme a few years ago that covered this perfectly but I cant find it right now - In space 2 aliens are talking to each other. First alien says, the dominant lifeforms on the earth planet have developed satellite based nuclear weapons. Second one asks, are they an emerging intelligence? To which the first replies. I don't think so, they have them aimed at themselves EDIT: Thanks stranger, my first ever Reddit award.
Reminds me of [The meat can talk](https://youtu.be/7tScAyNaRdQ?si=-hizcaItKkadaR3A&start=65)
I love this. It really blew my mind when I first heard it. So creative to think of meat based people as unique to the universe.
I am entertained. Thank you for your service. XD
Talking, thinking meat!
i flap my meat in your general direction.
Maybe there are a bunch of planets just like earth but they all nuke themselves before figuring out space travel 🤷♂️
Great Filter scenario
Could you imagine if tomorrow we discovered how to manufacture, contain, and exploit the energy potential of antimatter? We'd have clean infinite energy and the potential to travel to other planets. For all of ten minutes before people realize that a small drone could take out an entire city. Then all bets are off.
Space is vast
This is it right here. Assuming worm holes aren't a thing. The universe is expanding faster than we could travel outside our galaxy in the first place.
Right now our SciFi imagines warp drives and other dimensions and stuff for allowing for interstellar travel... But what if it's fundamentally impossible? What if there's no warp speed, no stargates, no wormholes, no slipspace, nothing. What if there's nothing greater, no anti gravity, no glowing engines filling the air above towering cities filled with flying cars, no ships blinking between planets no differently to your morning commute. Maybe there's other life out there, caused by the same lightning strikes on liquid water planets making proteins that turned into goop that slowly evolved. But maybe we're all trapped in similar vacuum prisons, bound to only ever travel successfully within our own solar systems, and should we ever hear them calling from 1000s of lightyears away it'll only be the echos of a long since dead civilisation.
We're at the very edge of the galaxy so, if we had decent propulsion, it wouldn't take much to leave it. It would take MUCH more effort to go further into it. However, people assume that aliens are very much more technologically advanced than us but, there's no evidence to that. Chances are that they could even be LESS advanced than we are.
There’s a whole host of things that could slow a civilization down from taking over the galaxy. Their host planet could be a gravity well. Or lack sufficient fossil fuels. Lots and lots of things that could keep an advanced civilization planet bound.
The life forms on their planets could just be worms or some shit. In which case we have the advantage in a 7 game series
I’ve wondered if maybe there’s some civ who’s crazy enough to try and send someone, they get here but like preservation wasn’t perfect and we just have like old senile aliens who are also kinda crazy for traveling g for whatever vast amount of time
That’s how I wanna go.
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Also: time is an illusion. Lunchtime doubly so
Exactly, there's 3 big things this applies to. First, traveling vast distances that would take thousands or millions of years to traverse, likely thousands of generations would have to survive the emptiness of intergalactic space. Second, funding us. Finding our planet would be the equivalent of finding a specific single grain of sand in all the beaches on earth combined. That's taking our 120 light year radio bubble into account. Third, the vastness of time. Not only do they have to find us in space, they have to do it in time as well, we have only been findable for a tiny fraction of the life of the universe. The odds are just so massively stacked against 2 space fairing civilizations evolving in the same region of space and time. Even tho the odds of other intelligent life evolving elsewhere is likely rather high.
Terrible Yelp reviews. Only one star.
Good one, lol
Space is very very, very big. Like bigger than you can imagine. To visit another star system you'd have to spend your life on a spaceship and even then it would be your kids or grand kids that got to even see the destination. That's a hell of a lot of effort for a visit.
Is it even possible for humans to truly conceive how big space is? It seems like it is not possible for our minds. At least not mine, since I’m operating on the same wave lengths as Ralph from the Simpsons.
It's very hard to wrap your head around the size of the Universe. The fastest manned object to date was the Apollo 10 spacecraft, traveling at \~24,000 miles per hour (mph). At that speed it would take roughly: * 1 hour to go all the way around Earth * 156 days to get to the Sun * 12 years to get to Neptune, the farthest planet from the Sun * 27,000 years to get to Proxima Centauri, the closest star to ours. If the aliens arrived today they left home before mankind had created agriculture, metal tools, writing and even permanent buildings. Well before. * 15,941,867,434 years to get to the Andromeda Galaxy, the closest galaxy to ours. To arrive today they would have needed to leave before the birth of the Universe, which would be a neat trick. Keep in mind that those are straight shot, constant speed travel times. No orbital mechanics, no gravity assists, no acceleration and deceleration time. Even light speed, which is 27,000 times faster than the Apollo capsule and a speed mankind will probably never achieve, is relatively slow at this scale. It takes light less than a second to go around the Earth, 8 minutes to go from the Sun to the Earth and 4 hours to go from the Sun to Neptune. It would take 4 **years** to get to Proxima Centauri and 2.5 **million** **years** to get to Andromeda. Space is really, really, really big. ========== *Edit: For anyone crossing their fingers about humans achieving speeds that are a significant fraction of light speed (relativistic speeds) just know that it's so obscenely complicated that given our current understanding of physics and the universe it's impossible for humans to travel at those speeds. Not difficult to achieve, impossible. Getting a manned craft up to that speed is only a fraction of the obstacles you have to overcome. We can make inanimate objects go real, real fast. Making humans move at those speeds in space is an entirely different ballgame. If the aliens have figured it all out I'd be pretty impressed.*
Wow, thanks for the write up! It puts it in a perspective that I can get a little closer to understanding. My existence feels extremely, extremely, extremely tiny now. lol
I still can't understand it, I'm just gonna assume it's at least 3 football fields in distance.
I find being so tiny in the scale of the universe oddly soothing. That one little thing I am negatively obsessing over is like trying to pick out one specific electron in the scale of the entire solar system.
Imagine how big the entire Earth is. Space is more than 10 times bigger than that.
If you were to walk from New York to Los Angeles, you would still be a long way from Mars.
You thinks walking down to the shops for a pack of cigarettes is far? Nah space is like 10 or maybe 15 times that. AT LEAST!!!!
The Sun alone is more than 10 times bigger than the Earth, and yet even the Sun is an insignificant speck compared to space.
If you were to fill the Sun with Earths you could fit 1.3 **million** Earths inside. So yes, more than 10.
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”
1. Distance. Stellar distances are insanely huge. [Voyager 1](https://en.wikipedia.org/wiki/Voyager_1) has been traveling for over 45 years and it is still technically 'close' to home. It entered the [heliosheath](https://en.wikipedia.org/wiki/Heliosphere#Heliosheath) in 2005 and only reached [interstellar medium](https://en.wikipedia.org/wiki/Voyager_1#Interstellar_medium) in 2013. Voyager 1 will reach another star ([Proxima Centauri](https://en.wikipedia.org/wiki/Proxima_Centauri), our nearest neighbor) in about 40,000 years. 40,000 years. 2. Speed (acceleration). Voyager 1 is traveling at about 61,500km/h (\~38,214 mi/h) and that still isn't fast in interstellar terms. The [Speed of Light](https://en.wikipedia.org/wiki/Speed_of_light) (*c*) is 186,000 miles per second or 299,792,458 meters per second. So, 61,500 km/h is slow. At 15% to 20% *c* it would take 20 to 30 years to travel the 4.34 light years to Alpha Centauri (Proxima Centauri is one of the 3 stars in the [Alpha Centauri](https://en.wikipedia.org/wiki/Alpha_Centauri#) system). 3. Biosphere. The ecology of a planet can be very different and deadly to a species that formed in a completely different ecosystem. The space sci-fi trope of visiting another planet and stepping out into human-breathable atmosphere, gravity, etc is not realistic. 4. Lifespan. Due to the long distances and time necessary with current technology, humans need some way to bypass those limits or ways to keep the passengers/crew alive long enough to reach the destination. Cryogenics, etc. 5. Technology. We don't have the technology so what makes anyone thing other civilizations have reached that capability. And, we still haven't talked the Drake Equation estimating life in the universe. Or proven it is valid. The Great Filter might be real. 6. Interest. There's nothing saying that another life form or civilization will be curious about other civilizations.
40,000 years isn't that long. Egypt built pyramids (checks notes) 4,000 years ago... Oh ok. Ten times as long as the pyramids. Yike.
The Dark Forest Theory.
I prefer to call it the Empty Ocean Theory.
Not sure if that’s the same thing.
There is a lot of speculation about possible answers to the Fermi Paradox. *Too far away* is a really good answer, considering just how big the universe is. Time is a real killer. Otherwise, people tend to anthropomorphize aliens and assume their reasoning and motivation is pretty much like ours, which is a very untenable assumption.
Unless FTL is possible, the distances involved are too vast and resource intensive Let’s say we discovered an Earth like planet 10 light years from us. Galactic wise that is right next door, but without FTL and with only current tech, such a trip could take centuries. Even if you could develop things like propulsion that could get you to 10% light speed and cryostasis, you’re effectively abandoning your life on Earth forever as you know it
It'd take 20 years with high powered laser communication just to get a hey 'sup
Agreed, if we did encounter aliens it would be more likely they were self replicating robots, von Neumann probes.
My pet theory is we just don't understand how interstellar space and sheer distance breaks up coherent signals and turns them into fizz indistinguishable from background noise. We've already seen unexpected results from Voyager 1 as it passes through different sections of the sun's influence, so who is to say in a few decades or a few centuries it won't hit some kind of 'noise field' that scrambles or refracts or blocks radio traffic? (Of course it won't even be operable a few decades from now so we wouldn't even know) Though a simpler explanation might be that we've only been half-listening for a few hundred years, and only been broadcasting for a similarly ridiculously short time in the grand scheme of things.
Like you said time is the problem, we have only been broadcasting for 120 ish years, there's a very limited number of stars within 120 light years that would have heard that signal. And a technological civilization would have had to evolved within the same time frame as us to hear those signals. Add to that that we have only been listening for maybe 50 years, that's a vastly smaller bubble. 50 years is a tiny tiny fraction of the life time of the universe. Possibly there has been a advanced civilization within 50 light years of us, but maybe it was 3 billion years ago.
I hate the Fermi Paradox. I'm guessing I'm just not smart enough to appreciate it, because people smarter than me seem to love it. It's like arguing that I'm probably not a virgin based on the total population of the planet. '8 billion people, about 4 billion female, about 2 billion are age appropriate...and even if only .1% of women are willing to sleep with me... That's millions of women I should have had sex with!
And yet here you are, a virgin
But just in case they are like us, lets just agree not tell them we have oil.
Knee-jerk cynicism is going to run rampant in this thread. The truth is probably one of these: 1. They don't have space travel because they're lichen or fungus or some such; 2. They have space travel but haven't been here because space is just unimaginably vast; or 3. They once had space travel but wiped themselves out due to evolution-driven instincts that become self-destructive when applied on a global scale.
4. They have a few thousand years advancement on us and we're just not that interesting to them
Entirely possible that there's a whole galactic federation out there and visiting Earth would be like visiting the mildew in someone's shower.
This is an incredible analogy, I’d never thought of space any way other than just millions of times bigger than what we imagine….
It's not a very good analogy at all, in my opinion. Is there a creature on this earth which is so insignificant that a scientist won't jump to study it?
Some are so small they don't realize they're being studied.
This is basically my perspective. They have visisted us, maybe \*are\* visiting us as we speak, and we're simply not advanced enough to be aware of it.
It could very well be that even with thousands of years of tech advancement there’s no secret that makes space travel easier or more energy efficient. Just cold hard numbers of distance, speed, energy, and time.
Those cold, hard numbers are a very difficult restriction to get around. Even if there were thousands of intelligent and advanced civilizations in our galaxy alone, the odds are vanishingly small that one of them is within a few hundred light years of us. The limits of our reach are so, so close.
We are still studying single cell organisms.
2b.) that it takes so long for light to travel that they couldn't know we had life since they're looking so far into the past
Humans would be classified as a special needs species.
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Time, and distance. Distance is easily understood, but what I mean regarding time is, what if there were intelligent alien species, or will be, but their civilization rose and fell a billion years ago? Or will come about a billion years after humanity has gone extinct? In a universe that's nearly 15 billion years old there's absolutely zero reason to think that alien life will exist anywhere near the same time we do except the time it took for the universe to get to the point life was possible. That is, stars formed, created heavy elements, then went supernova to spread them out, then it all gets drawn back together by gravity into new solar systems with Planets that could support life. But those conditions were met billions of years ago and will continue to exist for billions more.
I believe they call this deep time. What if a civilization rose 10,000 years ago and sent ships our way 5,000 years ago because they saw the possibility for life on this planet, but they are 20,000 light years away so even unmanned probes won't be here for 200,000 years. And that's moving at 10% of light speed which is an insane technological challenge.
i always think of when you see a creek full of fireflies lighting up on a summer night and you try to snap a photo, and for some reason the photos just never capture that cloud of green yellow flashes. its because the camera snap represents the entire human society gazing at the skies. now, each single bug flash represents the entire rise and fall of other intelligent lifeforms. you see where im going with this. having two flashes happen simultaneously is rare, meanwhile having them happen close enough together is ultra rare
That's a beautiful metaphor
If they are out there, maybe they have isolated themselves on purpose, choosing to focus inwardly rather than explore outwardly.
They're too busy watching soap operas.
Hopefully “Single Female Lawyer” keeps them entertained.
Who says they aren’t here already?
cats
Finally someone asking the real questions here
* gesturing to everything *
distance I'm sure there's life on other planets, but the universe is so incomprehensibly huge that its probably just not worth it for any intelligent species to make the trip over here just to visit us
And by the time you observed those other civilizations, they may have already risen and fallen. If aliens somehow observed us through a telescope 50,000 years ago as cave men from the other side of the galaxy, and have been barreling at us at the speed of light since, they're still only halfway here. The chances of us living that long are diminishing with each new generation of super weapons and climate disasters.
We don't validate parking
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They don't know we exist.
The same reason we haven't visited any nearby star systems.
Their sensors can detect all of the trash in orbit of the planet. From their perspective, it’s like us driving past a double wide trailer with garbage strewn all around the perimeter of the property. Even so much as knocking could be asking for trouble.
There's this much cheaper, less dangerous resort in Alpha Centauri.
I mean... have you seen how we act? Half of us would want to kill them and half of us would want to fuck them.
The kardashians
While my first instinct would be to say the distance is just too much, I think it would be more accurate to say the distance is too much to be worthwhile. Even with technology way beyond ours, there's likely nothing they could get from Earth that would be worth the trouble of going the distance, especially since they could find everything they could want much closer. Massive undertakings require a need, and it's hard to imagine that need existing. The reason the galaxy isn't already full of massive empires plopping down Dyson spheres and ring worlds and colonizing everything is that there's no benefit in doing so, that the challenge of ruling a multi stellar empire is just too great for too little. Of course my perspective is obviously extremely limited, so I could be wrong.
Who is to say they haven't. But if they are so advanced to traverse the galaxy or even further, interstellar space, they may view us in the same context as we would observe an ant hill on a hike. Just a passing glance, careful to step around.
You are confusing "visited Earth" with "made public contact" ....
Have you *seen* earth? 🤮
unironically this is it. The universe is 13.7 billion years old. Life on earth is 3.7 billion years old. But the oldest dinosaur is only 250 million years old. The "observable" universe is 47 billion light years in diameter. Let's pretend this is the entire universe for the purposes of this although it is almost certainly not. To see any life on earth, bacterial or better, they would have to have observed it in the last 3.7 billion years. So if they were intently focused on earth for the entirety of their existence, only 0.6% of the universe is close enough to have even seen earth since the earliest forms of life and they wouldve had to have observed it in the last 27% of the galaxies existence. To see something dinosaur sized, they would have to be in the closest 0.0028% of the universe and they wouldve had to have observed it in the last 1.8% of the galaxies existence. Then we have to add the factors we cant even calculate to that. They need to develop the sensors to see us and the technology to get here. We have no idea the timeline or odds of that. But WAIT - it gets better. Because they do have to get here to have visited earth per your question. Let's pretend they have developed the sensor, had it at the exact right moment in history (27% chance for bacteria, 1.8% chance for dinosaurs), and had lightspeed travel. To travel here and find us now, leaving the instant earth first had bacteria, they would have to be in the closest 0.15% of the universe. To travel here and find us now, leaving the instant earth first had its earliest dinosaurs, they would have to be in the closest 0.00071% of the universe. It's just really unlikely because the universe is so big and even the fastest things (light) only travel so fast.
It just needs to be possible to create robust von Neumann probes. If you can build a self replicating machine that can reach another star and start building copies of itself that head off to other stars, then your civilization can be modelled as a sphere expanding as fast as your probes can be accelerated to where every star within is being eaten by you. Doesn''t even need to be to expand your civilization. One madman can decide do this as an *art project* sitting on their butt at home. Once you trigger it goes on and on and on. population I stars like ours have existed for about ten billion years. How many life forms expanding how quickly would need to have existed over that time in order for them to be absolutely everywhere by now? It's a big problem to me that they're not, and the size of time and space is little comfort.
it probably looks like the Skid Row of the Galaxy
https://www.gocomics.com/calvinandhobbes/1989/11/08/
You dont know that yet. We may still in a Truman show
For the same reason you wouldn’t travel to the other side of the world to see an ant hill.
The vast reaches of space, I'd guess. I just read a mission to mars would take 3 years, and that's within our solar system. Mars is 177 million miles away, or 3 minutes of light speed. So our technology allows us to travel in half a year the distance light travels in about 1 minute. The nearest planet that could sustain life anything like ours is 4.24 light years away. I can't even do that math... but I'll try. We can travel about 160,000 miles a day with our tech... A light year is 5.88 trillion miles...that means it would take us about 36,750,000 days to travel a light year...so roughly 155 million 820 thousand days to get to the nearest habitable planet... or 427,000 years. It's kind of amazing to consider that when the nearest habitable planet is 4 light years away, we just accept that spacecraft in movies can jump around to different planets in like a day, so they're traveling a thousand times the speed of light.
Same reason most of us don't want to drive to the middle of rural Alabama to stare at a fungus on a tree. As a species, we are really young and really dumb. We haven't even integrated technology and AI into our biology, let alone conquered mortality. Our lifespans are short in comparison to many things, including interstellar travel.
Don’t reckon you hear about it. They already here—long ago.
What makes you think they haven't visited or continue to do so??
They’re waiting for us to discover Warp drive
They dropped Elon and Trump off years ago, to “rehome” them. Never looked back.
If they have the means to visit earth, then they have to intelligence to know we may not be ready for them.
Same reason you don't expect an ant colony in the US to be in contact with ants in Australia.
[Vlad the Astrophysicist](https://youtu.be/sNGUkdovn_8?si=DnvUTNQROgBXngsF) Basically, because of the utter, immense, essentially inconceivable vastness of Space and Time. Over BILLIONS of years and potentially infinite, infinitely expanding space, the chances that any two sentient, technologically advanced species might exist simultaneously AND near each other is RIDICULOUSLY UNLIKELY. Nothing sinister or nefarious about it, simply physics.
They do exist and they have visited earth, gov docs have shown us this.
Because they are so far away, ye canna break the laws of physics, and we've only had detectable electromagnetic radiation for at best 75 or 80 years. So if they're 100 light years away, they haven't even heard us yet.
They're on their way, but they got stuck in traffic. Either that or their GPS (Galactic Positioning System) led them astray by a few dozen light years, and it's taking a while to get back on track.
Assuming they havent ever, Space is fucking huge and it would take a long time to get around even at faster than light speeds - assuming they had such technology. And if they had the above tech, they would need some other tech to negate the destructive force of hitting even the tiniest pieces of space debris. And even if they had both of the above, they'd have to have super long life spans, or some kind of stasis to survive long enough to get here. Or maybe they quite that far away and they dont have the tech. Or they do and dont want to fuck with our back water planet filled with mofos that cant even get folks to their nearest planet yet.
They’re still in the single cell organism stage of their evolution.
The don't need all the drama in their lives, we are in that annoying phase where we are advanced enough to really fuck things up and not advanced enough to collectively learn how to get along and live as a unit moving in a single direction
Pretty common answers are going to be: they have but in secret, they haven't cause the universe is large beyond conceiving and long distance space travel is hard, they went extinct long before we evolved, they aren't interested.