What do you think the Great Filter is?

The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox.

https://en.wikipedia.org/wiki/Great_Filter

The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, "If life is so easy, someone from somewhere must have come calling by now."

https://en.wikipedia.org/wiki/Fermi_paradox

Personally I think it's photosynthesis. Life itself developed and spread but photosynthesis started an inevitable chain of ever-greater and more-efficient life. I think a random chain of mutations that turns carbon-based proto-life into something that can harvest light energy is wildly unlikely, even after the wildly unlikely event of life beginning in the first place.

I have no data to back that up, just a guess.

Nutteman ,
@Nutteman@lemmy.world avatar

I personally find the kardashev scale a pretty terrible way to measure the success of a civilization. Maybe the most successful life forms don't become technologically obsessed materialists determined to colonize everything habitable and drain the resources of everything else, yknow?

Melvin_Ferd ,

I mean then how did they become a life form

Nutteman ,
@Nutteman@lemmy.world avatar

I wasn't clear enough I don't think when I wrote that. I meant that as in the most successful intelligent life forms don't separate themselves from their ecosystems nor disrupt it in the way we do.

veganpizza69 ,
@veganpizza69@lemmy.world avatar

For us it's conservatism and its synonyms.

Anyolduser ,

Read like any history book.

Or just about any book, really.

veganpizza69 ,
@veganpizza69@lemmy.world avatar

I think that it's you who should read more.

Here:

Characteristic processes of human evolution caused the Anthropocene and may obstruct its global solutions | Philosophical Transactions of the Royal Society B: Biological Sciences

We propose that the global environmental crises of the Anthropocene are the outcome of a ratcheting process in long-term human evolution which has favoured groups of increased size and greater environmental exploitation. To explore this hypothesis, we review the changes in the human ecological niche. Evidence indicates the growth of the human niche has been facilitated by group-level cultural traits for environmental control. Following this logic, sustaining the biosphere under intense human use will probably require global cultural traits, including legal and technical systems. We investigate the conditions for the evolution of global cultural traits. We estimate that our species does not exhibit adequate population structure to evolve these traits. Our analysis suggests that characteristic patterns of human group-level cultural evolution created the Anthropocene and will work against global collective solutions to the environmental challenges it poses. We illustrate the implications of this theory with alternative evolutionary paths for humanity. We conclude that our species must alter longstanding patterns of cultural evolution to avoid environmental disaster and escalating between-group competition. We propose an applied research and policy programme with the goal of avoiding these outcomes.

https://lemmy.world/pictrs/image/4c98d163-d037-41e0-9092-479db76236df.jpeg

Figure 2. Dimensions of environmental management create an attractor landscape for long-term human evolution. Environmental sustainability challenges (curved frontiers) require a minimum level of cooperation in a society of a certain minimum spatial size. Alternative potential paths move humanity toward different long-term evolutionary outcomes. In path B, competition between societies over common environmental resources creates cultural selection between groups for increasingly direct competition and conflict. Path A, growing cooperation between societies facilitates the emergence of global cultural traits to preserve shared environmental benefits.

Anyolduser ,

A Great Filter is way, way bigger than that. Something that prevents a civilization from being able to expand into space. This includes things like "you can't make fire on this planet and therefore are never able to learn to work metal" and "supernovas sterilize regions of space before species can leave them".

Even the worst ecological disaster - one that kills billions - will not prevent humanity from eventually recovering, rebuilding, and expanding.

Under no circumstances (even Cold War mutually assured destruction) can human politics be a Great Filter. Thinking that it can be is small-minded and petty.

veganpizza69 ,
@veganpizza69@lemmy.world avatar

I see, so you don't understand what's happening on the planet.

Don't worry, you're not alone, you represent the majority.

theneverfox ,
@theneverfox@pawb.social avatar

I don't think life is rare, nor photosynthesis, but complex life might be. A planet needs to be really thriving with life for it to be worth it to go down the path to something like animals

But I think the bigger filter is much stranger.

Humans are a hive-like species. We're not just social - we're insanely interdependent, we don't function on our own and yet we've ended up in this place where we (often) try to individually succeed, even at the cost to our community

We're greedy enough to want the stars, yet interdependent enough we could only swarm over them in endless numbers

There's many problems with the fermi "paradox", but personally I think one of the largest is assuming all species would spread like a cancer blotting out the stars

A more individualistic and long lived species might instead be careful explorers, taking what they need and leaving little sign of their passage. A more communal species might be careful and control themselves to not destroy pointlessly. They might also feel no desire to contact other species

We're just the right mix to want everything a star could give, and to want to find others at great energy cost

Cryophilia OP ,

God help the universe if we ever discover FTL travel and escape the prison of lightspeed.

MintyFresh ,

I have a new religion!

Prometheus didn't gift us fire and cognition. Lies. We are Prometheus's curse on the universe. Nothing more than a plague on the gods creation, concocted for some slight we can never understand. The sum of us, brought into being, then tossed into the void and forgotten. To spread like an oil stain across creation.

Cryophilia OP ,

"And behold, I Myself am bringing floodwaters on the earth, to destroy from under heaven all flesh in which is the breath of life; everything that is on the earth shall die." - Genesis 6:7

"If you had not committed great sins, God would not have sent a punishment like me upon you." - Genghis Khan

Allero ,

I don't think there is a single universal Great filter, and living and then potentially sentient beings with various traits will face various obstacles.

First, life needs suitable materials for polymers and a lot of energy. Most places don't have both.

Next, basic blocks of life that would be self-replicating and adaptive should be randomly generated, which is extremely unlikely and literally took over a billion years on Earth, a planet with generally great conditions for such process.

Then, those blocks should be able to get together to form complex structures - ideally, many separate ones, so that one event wouldn't destroy the entire effort. Earth had it easy, with billions of super simple life forms.

Next, assuming life survived up to this point in a potentially unfriendly and ever-changing environment, bombarded by UV light and exposed to myriad of sources of damage, it should not destroy itself or environment too badly to never recover. Earth had periods when life generated too much carbon dioxide or too much oxygen (yes, that too was a thing), and those were critical points at which our story could very much end.

Then, life has to evolutionize and get into complex forms, either by forming multicellular organisms or by making a cell a powerhouse of everything.

Then, life has to get sentient, and some kind of response system should be available and get highly complex.

Then, most of the sentient creatures just won't be tribal, and civilization requires society and a common effort.

Then, many more won't be expansionist, and will die out in some small region.

Many also won't be competitive, which would slow down evolution.

For those species who are competitive, they shouldn't destroy each other while they're at it, and this is currently one of the risks of our own.

And after all that, they should develop space travel and either get as developed and decisive and resource-rich as to send a generational ship to some random planet named Earth populated by genocidal monkeys, or to somehow hyperdrive here. They can very much decide it's not worth it, and they may be so far away we couldn't see signs of their civilization.

LordGimp ,

Pushing Ice by Alastair Reynolds is one of my favorite scifi books and it deals with this question in an interesting way. It proposes that Time is the great filter. Life exists in this galaxy, but intelligent life is so fleeting when considering galactic distances that the probability of one sentient lifeform finding another during their "peaks" is vanishingly small. Extinction, societal collapse, evolution to a higher form, whatever you want to imagine, it all gets in the way of the fantasy of meeting a thinking being from another planet.

Maggoty ,

I think we're the first. Or rather in the first wave of intelligent life. It could take a thousand years just for a message to reach us. On the theory that life has evolved to this point as fast as possible over the life of our Galaxy, there's no filter. There just hasn't been enough time for contact to occur.

LordGimp ,

Time itself is the filter. I don't think we are the first, but I don't think we will every find any other intelligent life. The universe is too big and our lives are far too short to make any sort of attempt to travel or communicate across those distances ourselves. I'm also not entirely confident our idea of what a society is will last in any meaningful way over the timespans required. Our longest lasting dynasties rarely make it more than a couple hundred years. Space is just too big for us to work with using our current understanding of physics.

pelletbucket ,
@pelletbucket@lemm.ee avatar

evidence of human existence has only gotten what, 150 lightyears out into space?

Cryophilia OP ,

Eh. The amount of oxygen in out atmosphere is pretty much impossible by non-living processes alone iirc. Anyone who can do astro-spectroscopy can probably tell there's life here, from thousands of light years away.

pelletbucket ,
@pelletbucket@lemm.ee avatar

and if life is as abundant as we think, how are they going to tell the difference between intelligent and non-intelligent life

Cryophilia OP ,

Life is so rare, finding ANY life is worth investigation

pelletbucket ,
@pelletbucket@lemm.ee avatar

that has nothing to do with why I asked that question lol. if you have to investigate every single one that shows signs of life, that would mean investigating a lot of worlds before you find any with intelligence.

HurlingDurling ,
@HurlingDurling@lemmy.world avatar

By the color of their hats /jk

Anyolduser , (edited )

Boy, Lemmy sucks donkey dick. For every one legitimate answer there are two or three edgelord answers like "capitalism" and "the internet".

Here's an answer that hasn't come up yet: cooperation among mono cellular organisms. I don't mean the development of polyp analogues or colonies of single celled organisms; I mean getting down to mitochondria. Brace for wild oversimplification.

Before mitochondria, life had a hard time creating enough energy to do much more than barely stay alive. The current line of thinking is that one organism ate another and didn't digest it. The two organisms worked symbiotically, one handled energy production and the other handled getting food and staying alive.

Just about every living thing utilizes mitochondria and if the current idea that mitochondria were actually symbiotic organisms is true, that means that what was likely a chance "sparing" of prey is the underpinning of all complex life.

The odds of that happening are ridiculously low. There could be simple life in tons of places even within our own star system, but if the mitochondria-like symbiotic capture never happens for those extraterrestrial organisms, then complex life is probably unlikely to develop.

Cryophilia OP ,

Edgelord teenagers are a plague on lemmy

Anyolduser ,

A - fucking - men

scottywh ,

Still not as bad as reddit though

Gregonar ,

Maybe cooperation is hard wired just like competition. It might be less likely but hardly impossible.

Anyolduser ,

I'd hardly describe it that way. It took untold trillions of predator/prey interactions over the hundreds of millions of years that single celled life existed for it to happen. That's more or less brute forcing the problem and it took geologic timescales to happen.

If you ask me to point at a hurdle stopping civilizations from developing that looks awfully reasonable.

Gregonar ,

Ultimately we don't know much about that era of time, but I suspect it was less like fumbling around for millions of years looking for a light switch, and more like the gradual warming of the planet with warmer and cooler seasons/years.

Iirc at least one of the other things related to development of eukaryotes was that atmospheric oxygen had to first be generated by early cyanobacteria.

So maybe that proverbial light switch was being flipped millions of times through random encounters but only became more viable after the voltage (atmospheric oxygen levels) became high enough. Maybe that's the reason it took hundreds of millions of years, because transforming by bacteria just takes that long.

We just don't know unfortunately. However, we DO know about species getting wiped out by asteroids or human cultures getting wiped out by disease or conflict with superior cultures. Any of these filters seems more of a hurdle to me than the development of eukaryotes.

pelletbucket ,
@pelletbucket@lemm.ee avatar

your paragraphs complaining about it are a lot more annoying than the people who might not be being totally serious on the internet for a minute.

Anyolduser ,

If by "paragraphs" you mean two sentences, sure.

If you'd bothered to read past those two sentences you'd see that I was making an offhand comment before answering the question.

pelletbucket ,
@pelletbucket@lemm.ee avatar

nah if you open up just insulting all the people around you, I don't owe you reading the rest of your post.

Anyolduser ,

Case in point for Lemmy being a shit hole.

ChewTiger ,

Good answer.
This seemed relevant enough to share, it's certainly interesting.
https://newatlas.com/biology/life-merger-evolution-symbiosis-organelle/

pelletbucket ,
@pelletbucket@lemm.ee avatar

seriously though, I think life on other planets probably just usually evolves underground, so even if they develop some sort of intelligence they're not looking up at the sky so they have no motivation to explore beyond their atmosphere no matter how advanced they get.

there was a planet in The hitchhiker's Guide to the Galaxy universe that had thick cloud cover so that people never even conceived of an existence beyond their planet. when a spaceship crashed there, it never even occurred to them that it might have come from the sky

pelletbucket ,
@pelletbucket@lemm.ee avatar

sentience. I think it usually immediately leads to suicide

Cocodapuf , (edited )

I don't think there is a great filter. I think there's an easy solution to the fermi paradox that doesn't require great filters, we're just the first intelligence in this galaxy.

Here's my reasoning: intelligent species that manage to develop space travel probably do tend to expand out into their galaxy. When they achieve this level of technology they can settle most of all of their galaxy in a matter of 10,000 years or so. That time period is very brief on an evolutionary scale. It's estimated that life began on earth 3.7 billion years ago. That means it took about 3.7 billion years for earth to produce intelligent life, and then from that point it would take a mere 10,000 years to reach modern day, and 10,000 more years to settle the whole galaxy. That expansion happens so quickly compared to how long it took the planet to develop intelligent life, that the chance of two civilizations rising at the same time becomes very small.

It all boils down to this: there are no intelligent aliens out there in our galaxy, because we are the first intelligent species in our galaxy. We know we're the first because if we were second, then aliens would already have settled this star system.

Probably there are lots of alien civilizations out there in the universe, but they're in different galaxies.

MonkderDritte ,

Or we just don't know, because every possible indicator is gone after a few hundred million years or our star system was still a proto disk when they were around.

smb ,

and the ones finding apes on a planet just short ahead or into the beginning of those 10000 years might think "well lets teach them how to stack stones and let them call us gods for just showing some of our million years old and cheap replicated tech gadgets pewpew, how amusing! but now lets go on, this planet has water but way too much oxygen and also there is axial precession that would change weather over only few hundrets of thousands of years if not less, not the planet of choice for eternals like us, duh!"

Cryophilia OP ,

But why are we the first. That's the question. Given the age of the universe, statistically it should have already happened by now. Unless something was stopping it.

Cocodapuf , (edited )

That's definitely the right question! And honestly we don't know, but it's evident that we are first.

Given the age of the universe, statistically it should have already happened by now.

I'm not sure that's true... I'm pretty sure that our sun is old for a main sequence yellow star in our galaxy. When you compare how long it takes for a star to get to the point ours is now, compared to the age of our galaxy, I believe it suggests that sol is part of a first wave of stars of its type. So if life really requires a star like this one to start up, then intelligent life starting just now could be right on time.

Now why is our start perfect for life? Again, we don't know, but evidently it is. Sadly we only have this one data point, this is the only star where we know there's life. So assuming that something about our type of star is perfect is about as sensible as assuming that life could start around any star. Is it that other kinds of stars produce too much radiation in the Goldilocks zone? Or is it that other kinds of stars are too variable in the amount of heat they produce? Or that other kinds of stars don't tend to have rocky planets? We don't know, but something about main sequence yellow stars could be special, and we have one of the first of those stars in this galaxy.

So declaring "we're the first" requires some assumptions, but they aren't crazy assumptions, and a lack of evidence of other older civilizations makes those assumptions stronger.

And to your point, the universe is much older than this our star, so I suspect intelligent life has developed many times before us, at least in older galaxies. But sadly I don't expect us to ever meet life from another galaxy. While I think stars within a galaxy are close enough for travel between them, galaxies are very, very far apart. I don't think life has much chance of traveling to other galaxies, at least not without some method of ftl travel (which I am also not optimistic about).

Tlaloc_Temporal ,

It might have something to do with the available elements.

We live in a population I star system, full of crap spewed out from long dead stars. Perhaps it is exactly this crap (like copper, iron, nickle, manganese, and possibly the bulk of carbon and nitrogen) that allow life to develop with enough agility to survive mass extiction events with any kind of complexity.

Or perhaps it's exactly those mass extiction events that have allowed enough breathing room for new paradigms to take hold. Maybe our 5-7 mass extictions that didn't end life entirely are exactly what is needed to prevent stagnation. We just happen to be on the edge of dead and too slow.

Subverb ,

It could simply be that the rise of life is wildly more rare than we think.

Cocodapuf ,

Yeah, it totally could be.

Xanis ,

Statistically I shouldn't fail a 99% roll 7 times during a single mission in XCOM and yet here we are.

Cryophilia OP ,

"weird coincidence" is one potential solution to the Fermi paradox.

creditCrazy ,
@creditCrazy@lemmy.world avatar

In my sci Fi that I've been working on has this theory being true but I also play with asking what is the point of colonization. In my story humans have colonized mars to study the fossils and what life used to be like on Mars. However the people there after a few generations separate from earth. Earth doesn't do anything about it because not only can mars use telescopes to see our ipbm years before it arrives and have that time to shoot our ipbm before it arrives but invasion will destroy the fossils we care about. And that's all assuming history won't just repeat itself. Eventually the mars colony expands until it breaks into different nations all fighting echother to become the first martin superpower. So everything that earth cares about gets destroyed by war anyway and earth is pointless to mars without life and water. Eventually the sun becomes so old that everyone feels the need to move their populations to another solar system. And only then de humans discover alien life. Only to discover that it's currently 900 billion years beyond 2024 and aliens are just now figuring out radio waves and rockets and are more concerned about developing eugenics than discovering humans.

sparkle ,
@sparkle@lemm.ee avatar

The Milky Way is 100,000 light years across. It's physically impossible to settle that in 10,000 years

Soggy ,

That assumes that interstellar travel is possible. Physically, economically, socially, there's a lot of boxes to check for near-light extrasolar expansion (let alone FTL, which probably is impossible)

I think the easy solution to the Fermi Paradox is that we're stuck in our fish bowl and so is everyone else.

Cocodapuf ,

That's true, it does assume interstellar travel is physically possible, but at this point there are forms of interstellar travel that we know are possible.

Solar sails for instance, we know those work, we've tried it. Now if you wanted to travel to another star system with a solar sail, it's just a matter of scaling that proven technology way up. We're not ready to do that today, and we won't be ready in the next 20 years, but to think that we wouldn't be ready in 500 years, I find that idea far fetched.

But a much better technology would be fusion propulsion. With fusion drives you could get your cruising speed up to a meaningful fraction of the speed of light (perhaps 5-10%). At that rate you can make it to the closest stars in less than 100 years. And that technology is not at all far fetched. We truly are approaching working fusion power plants, it's extremely likely that we can eventually develop fusion propulsion, or at the very least, fusion powered electrical propulsion (ion drive).

As for if it will ever be economically possible, I'm not at all worried about that. The fact is, there are a lot of resources and opportunities right here in our solar system, just waiting for people to utilize them. So people definitely will start mining and manufacturing in space eventually. And as we start to operate more in space, we will naturally continue to iterate and improve our methods of getting around. In short, over time it's going to get cheaper and cheaper to make space ships and we're going to get better and better at doing it. The economic factors are likely to fall into place eventually.

And finally, will interstellar travel ever be possible socially? Hey, your guess is as good as mine. I don't think we have any way to answer that...

oo1 ,

I think most lifeforms will have more pressing matters than wasting large amounts of time an energy blasting signals in to space for no reason, or listening to the sky.

Maybe those civilizations that waste more energy chasing aliens die off sooner due to wasting resources on sci-fi bullshit and ignoring their real problems at home.

Cryophilia OP ,

I disagree. I think there is no more important thing we have ever done or will ever do as a civilization, than try to make contact with alien life.

Steve ,

Sadly it may be the speed of light.

All these intelligent species are simply trapped in their own solar systems for all eternity by an unbreakable natural law.

Cryophilia OP ,

That is very sad.

Aggravationstation ,

But surely generational ships would get us over that?

robolemmy ,
@robolemmy@lemmy.world avatar

AFAIK there is no known energy source that would keep a generation ship powered for the duration of an interstellar flight.

The person to whom you responded is half right. The speed of light is half of the barrier to interstellar travel. Entropy is the other half.

SkaveRat ,

just reverse entropy

Cryophilia OP ,

INSUFFICIENT DATA FOR A MEANINGFUL ANSWER

rovingnothing29 ,
@rovingnothing29@lemmy.world avatar

import fuckit && !!

groet ,

Would you need a power source? If you aim your ship correctly, then put everything alive into cryo, the ship could go completely dark, vent all heat and become a frozen rock. Then after [very long time] the ship enters the vicinity of a different star and can be reactivated and unfrozen using solar energy.
You dont need energy to maintain cryo if the whole ship is at 1° kelvin.

(Of course that relies on cryo sleep being possible)

Cocodapuf ,

Or synthetic life. (Robots)

groet ,

Only if they can be turned off (same as the cryo sleep). The whole ship either has to have enough energy to last potentially 100000 years (no theoretical power source exists like that) or enter a state of 0 energy consumption. Solar/radiation collectors dont work if you are to far from a star. Synthetic life still needs energy

Cocodapuf ,

The whole ship either has to have enough energy to last potentially 100000 years.

Well, that depends on how far you're going. If you pick a nice close target, let's say 3 light years away, you can potentially get there pretty quickly. With fusion propulsion systems you could make the trip is something like 70 years, coasting most of the way. I'd need to check the math to get exact numbers, but I recall fusion allowing for pretty reasonable trip times.

But if you can survive for hundreds or thousands of years, then solar sails become an option. Then it becomes a materials science problem of how thin can you make a sail that will still hold together. The greater the sail to payload ratio, the faster you go.

ahornsirup ,

Also, you'd need to know for certain that the planet you're sending your generation ship to is habitable for your species. While this may be technologically trivial for a society that can build a functional generation ship, the timescales for such projects (literally hundreds or even thousands of years from the launch of the probe to the yes/no signal) makes it extremely difficult to actually organise.

Cryophilia OP ,

Lol we get to the planet and find it was obliterated by a gamma ray burst 50 years ago

Hugin ,

Or just send a lot of ships and hope one or two find something good.

Cryophilia OP ,

Plus isn't the rate of expansion of the universe increasing? So at some point, even going at light speed, your destination will recede faster than you can travel.

Cocodapuf ,

Not really. Galaxies are pretty stable, stars orbit around the central black hole in the galaxy. You can absolutely travel between stars in the same galaxy, even if it takes a thousand years.

Steve ,

No. At best maybe a few reach the nearest inhabitable solar system.

amorpheus ,

Until we figure out how that is possible outside of theory, it is just that. We have no plans that address actually keeping a spaceship working on such a timescale, and keeping the crew alive on top of it.

Considering we haven't seen any generational alien ships visit, it seems like nobody else has figured it out yet, either.

Perfide , (edited )

Not really, no. Generational ships might make colonizing the nearest star systems possible, but even colonizing our own galaxy would require some kind of suspended animation. The milky way is between 100,000-200,000 light years in diameter so even at the speed of light, you're looking at a travel time that is ~33-66% of the time that humanity has even existed(homo sapiens are currently estimated to have become a distinct species 200,000-300,000 years ago)... just to go to ONE star system out of the hundreds of BILLIONS that exist in our galaxy. You're gonna need generational ships so self-sustaining and capable that the generation that actually arrives at the destination will have long forgotten the point of the trip and might not want to leave the comfort of the ship.

Still, colonizing our own galaxy is at least theoretically possible, given enough time. The real filter is just how unimaginably large the universe is. The vast, VAST majority of the observable universe is FOREVER out of our reach, as it is expanding away from us faster than the speed of light. Then there's the unobservable universe, which could literally be infinitely bigger than the observable universe for all we actually know.

Cryophilia OP ,

That's why faster than light travel is the holy grail. Without it, we're just kind of stuck.

Imagine if wormholes had zero constraints on the physical location of the other side of the wormhole though. We could open a portal to OUTSIDE the observable universe. What a mindfuck. We might even find a false vacuum decay racing towards us at the speed light, or regions of space that are contracting instead of expanding, or initiate a new big bang by opening a wormhole to an area of space where that hasn't happened...we could travel to a point where we can watch the milky way get formed, since the light of its formation is just reaching that region of space. If it turns out the heat death of the universe is just a local phenomenon, we could continue expanding forever beyond it. World without end.

AA5B ,

Generational ships wouldn’t have to reach the edge of the galaxy, just the next planetary system. There’s no reason civilization needs to remain centered on Earth, either. Think of it as a wave traveling outward, where it eventually reaches the edge, by many smaller hops. It will also eventually reach earth, where they might wonder at signs of a prehistoric civilization. Actually, think of it like the Middle East, where empires rise and fall, crusades and jihads burst through, religions rise out of nowhere, people speak many different languages. A galactic civilization could be dynamic and ever changing, distance can make us strangers to each other, the fate of any planet matter only to its inhabitants and neighbors

Perfide ,

Sure, that's an option. It doesn't really change my overall point though that anything beyond galactic colonization is unrealistic on any time scale. Our next nearest neighbor, the Andromeda Galaxy, is over 2.5 MILLION light years away, over 10 times farther than my "crossing the milky way" example, with nothing in-between to make a pit stop if needed, you have to cross the true void of space to get there.

And that's just to get the next nearest galaxy. Current estimates suggest the observable universe contains 2 TRILLION galaxies.

AA5B ,

True, you’re not getting to the next galaxy. However within the galaxy, your generation ships only need to work for a century or two per voyage. That’s at least conceivable

treefrog ,

Information can travel at light speed. So, I think there's more to it personally

Steve ,

Light speed is very slow

Perfide ,

There doesn't need to be more to it than that. The observable universe is over 93 billion light years in diameter. That means even at the speed of light, it would take over 6.5x longer than the universe has even existed for anything to cross that distance... except the universe is expanding faster than the speed of light, so actually you need to go significantly faster than light to make it across. FTL is, sadly, still firmly in the realm of science fiction, so to the best of our current knowledge most of the universe is permanently inaccessible.

HANN ,

Even if you had a super intelligent species that can make Dyson spheres and travel at the speed of light the observable universe is beyond vast. I don't know much about cosmology or our ability to detect light but given humans have only been looking into the sky for a couple centuries, not being able to see a thimble in the ocean seems like a non issue. I think if you scale the observable universe down to the size of earth the speed of light becomes 0.05 mph.

Foni ,
@Foni@lemm.ee avatar

Energy needed to leave your planetary system vs energy available on your planet of origin.

We have not yet overcome it and I am not sure that we will achieve it.

Cryophilia OP ,

Well, we've already sent a couple of probes out of the solar system, but they're not really going fast enough to have any meaningful interstellar impact.

Foni ,
@Foni@lemm.ee avatar

Yes, but I mean leaving the planetary system not only with isolated elements, but with parts of our civilization.

  • All
  • Subscribed
  • Moderated
  • Favorites
  • •
  • [email protected]
  • kbinchat
  • All magazines
    •