Thanks for the explanation! That does seem to encapsulate my feelings.
One thing though. Sure, if you assume that humanity will last for billions of years and colonize the galaxy then SOMEONE has to be born at our time and, if they were, they would think it strange.
However, we don’t know how ‘big the bag is’…and…I can’t really explain the logic…but if you don’t know how big the bag is and you find yourself 6000 years only from the start of civilization…I can’t help but think that has SOME information on how big the bag is. It doesn’t make it certain but I would think it would increase the probability the bag is small?
If you were in Roman times, and only 4000 years from the start of civilization, would you have more or less information as to the possible future of humanity than now?
IMO, the Fermi paradox is alarming. However, and this is just pulling stuff out of my butt/no expert, but I get the feeling intelligent life is pretty rare and that the great filter is behind us (probably multicellular life if I had to bet). I think when/if we get out there we will just find the equivalent of pond scum if even that
What is kind of fun is that up until recently the proposed solutions to the Fermi Paradox have been a bit depressing. However, I heard a positive one recently…and that is the the Multiverse exists and is accessible. So, alien civilization just explore that (basically versions of their own home planet) rather than the hardness of interstellar travel
But I wasn’t born then. If the future was not certain then, yes, I think it would. However, we know this year exists for mankind so it makes it hard to use this Roman.
I’m not thinking we are doomed TOMORROW…but I think the probability we go, say, another 10,000 years is lower because of this. If that makes sense.
I think that I’d probably accept FTL and time travel before multiverse travel, but it still runs into the same problems they do, if we can travel between universes, then shouldn’t we be visited by Earthlings from another universe?
I don’t think so. If the multiverse is infinite, then even if a gazillion ‘Earths’ were exploring the multiverse I think the odds they would find us would be slim? Heck, even if an infinite number of ‘Earths’ were out there exploring I still think the odds are slim?
I also don’t think this is possible…but it is a rare ‘positive’ solution to Fermi.
I think this also runs into the standard “where are the replicating robots?” argument anyway.
That is to say: any species a little more advanced than us could seed the galaxy with replicating robots at relatively little cost. So, even if it’s the case that exploring the multiverse is orders of magnitude easier than interstellar travel, for this to be the primary solution to the Fermi paradox, we need to posit every individual, of every civilization, of every species never chooses to launch such a device.
With more than a handful of advanced ETs this already becomes quite implausible (though of course we can’t know).
I think it is worth noting that there would not be an “infinite” number of earths out there. The Poincare Recurrence time is 10^10^10^10^2.08. That’s how many years it will take for all possible combinations of our universe to occur before things start repeating themselves. It is a stupidly long time and big number but it is not infinite.
Also, remember that if there is a multiverse there are almost certainly far, far more without life in them than those with it.
So, unless you can pick which multiverse you want chances are much better you will find one devoid of any life than one that is a near duplicate of earth today. Kinda like the bag of beads mentioned above. Out of a million beads maybe five are red ones. You would be much more likely to get a different color.
That’s assuming those other universes follow our laws of physics. So you could reach in and instead of a red bead you get a live octopus. Or it IS a red bead, but instead of atoms it is made up of anti-atoms (could an anti-matter bead have color, ie reflect photons at a specific wavelength? What would happen if it touches one of our photons? Will an annihilation occur? Are there anti-photons?). Or instead of a bead it is the concept of the color red.
If you haven’t yet you should go see the movie Everything Everywhere All at Once. I think you’d like it. Pulling an octopus out of the bag just scratches the surface.
I recently read (or tried to read as I don’t understand the math) a scientific article called ‘Relative Likelihood for Life as a Function of Cosmic Time’ which makes the argument that the universe will be best able to support life in the year ten trillion. Seeing how we’re around year 14 billion, the universe is in its infancy.
perhaps thats why we have the fermi paradox. Supposedly the universe couldn’t support complex life until a few billion years ago due to high rates of gamma rays, and the universe is barely in the intro stages of it being able to support life (it won’t hit its peak for ten trillion years).
Also keep in mind the stellar era is just one era in the universe. On a long enough timeline, 100 trillion years becomes a rounding error.
Humans don’t even have theoretical means to pursue at this point. How would we get to the stars? Wormholes?
If we tried to send a colony vessel at realistically attainable speeds, where generations live and die on the journey itself, how many years are we talking? Hundreds or thousands? Assume we’re going straight to Proxima Centauri, 4.24 light years away. (Google says that’s the closest habitable planet.)
The big problem is unless we crack that faster than light problem, we can never have a single civilization that spans multiple stars. Not even theoretically, when even just communication has a 4-year lag between responses.
EDIT: Google says Voyager 1 would take 73,000 years to get there.
I was speaking specifically in the context of great filters of the Fermi paradox.
Bearing in mind how quickly humans have gone from knowing nothing of space to landing a probe on an asteroid, and humans on the moon, even the most pessimistic estimates would say we should be able to launch slow generation starships within thousands of years, which is an “eyeblink” in the context of the life of the galaxy.
Of course, humans might destroy themselves before we arrive at that technological level. But that wouldn’t change the fact that an incredibly warlike and aggressive species nevertheless came extremely close to seeding the galaxy. This implies that self destruction due to war is not a good candidate for a great filter.
But who would claim that? There are many civilizations of earth right now, why would we need to posit a single one spread across multiple star systems?
Lets say we have a person, a remarkable individual who never has a boring or univentful day in their life until they reached 80 years old. They lived to be 120 and from 80 to 120 they had an extremely univentful and boring life. Did this person actually die at 80 somehow? Obviously not, they still in fact lived to 120 and would be considered one the oldest people to have ever lived at the time of their death.
Same with the universe. Just because, according current understanding, the overwhelmingly vast majority of the projected time of the universe will be pretty univentful comparatively, doesn’t mean it we can somehow say it ended long before it actually does, like at a point when the last star is diminished or something.
If the universe ceses to exist after what someone arbitraly decides what they deem “interesting”, like when the last living thing or star, ceases to exist, where do the things that still continue to happen if not in a universe? Is it, like, a zombie universe? Is heat death then when even the zombie has been shot to the head and turned to dust? I guess there is a sort of strange logic to that.
The whole OP is a purely semantic argument. While points 1 and 2 may agree when the universe started, they simply have different definitions what exactly is a “dead” universe. The first one bases it’s claim on arbitrary and biased emotional reasons, the second on scientifically, philosophically sound and rational ones.
We can potentially say that the universe is almost or virtually dead before it actually is truly dead but that is as far as we should go I think. The true end of the universe is when a theoretical outside observer can not and will never detect any changes happening in it anymore. Any other definition would seem arbitrary and biased to me.
Of course, there are any number of predictions on when the true death of the universe actually occurs. But it still seems that it will take a pretty damn long time, so the current universe is barely even a zygote.
We could examine this fact a little more closely.
Currently red dwarfs outnumber every other kind of star by more than three to one. As they age, they will get brighter, because of the buildup of helium in their cores; eventually many red dwarfs will become as bright as the Sun, and remain that way for hundreds of billions of years. The galaxy will look very different in a trillion years time- all the stars we can see now will have faded into oblivion, either as white dwarfs or as neutron stars or black holes. But the red dwarfs will be brilliant, and they will heat their local planets with enough energy to sustain biospheres that could last for hundreds of billions of years.
Humans might not exist in this far distant future, even as memories - but there could be much longer-lived civilisations around the most common stars in the sky.
I don’t believe the human motivation to explore, gobble resources and colonize every habital inch of Earth is at all equivalent to an advanced civilization’s motivation to explore, gobble resources and colonize every inch of our galaxy.
Let’s say there are a handful of advanced civilizations (AC) in our galaxy that have mastered interstellar travel and also coincide with our timeline. As per the Fermi Paradox, why don’t we see evidence of their existence? I believe the answer is that they have no motivation to explore, gobble resources or colonize anywhere near us. What does our neck of the galactic woods offer that they want? Nothing.
Distance: If the handful of civilizations in our galaxy are dispersed rather equally, then even the closest AC would be ~20,000 ly away. Advanced or not, that’s a very large distance to expect benefits from exploration. Assuming FTL is the ultimate universal speed limit, gathering resources from our star system and bringing them back to theirs would take >40,000 years. It’s not equivalent to spending a couple months at sea in order to gather sugar or tobacco from distant lands on Earth.
Resources: Even if the closest AC doesn’t mind spending >40,000 years to enjoy the fruits of their labor, what resources does our solar system offer them that they can’t get much, much closer to their home? None, that I can think of. We have the same elementary particles in our solar system that they have in theirs, or in closer-to-home systems. Our sun isn’t anything special. They have stars closer to home to reap energy from if they need it.
Self-replicating probes: what intel is worth waiting >40,000 years to receive? Evidence of life on Earth? So what? How does that information help them in any productive way? Do we pose any danger to them? No. Is our bio-physiology particularly interesting or unexpected? Probably not. Scoping sites for future colonization? They have better places closer to home. Sure, perhaps an AC could send self-replicating probes throughout the galaxy, but why would they? Just to litter the galaxy with more junk?
Colonizing the galaxy: Human motivation to colonize and dominate the entire Earth (and possibly close-by planets and star systems in the future) is not equivalent to colonizing and dominating an entire galaxy, even if it’s theoretically possible. Given the vast distances involved, I see no way to have any type of control over the galaxy even for a super advanced civilization. And, why would they want to? Bragging rights? They can populate their little green men over great distances as much as they want without getting anywhere near us. There is no shortage of space, energy or resources in the Milky Way. There’s no need to travel tens of thousands of light-years to do whatever your advanced civilization wants to do.
I believe life is common in our galaxy and there may even be a handful of advanced civilizations present in our time frame. But, I don’t find the Fermi Paradox paradoxical. Nobody has any desire to visit us, that’s all. We’re like the wallflower in the ballroom and nobody wants to dance with us. Deal with it.
The photon is its own antiparticle, and "anti"matter would interact with light in exactly the same way as “normal” matter (the quote marks are because, in several cases, there’s no unambigous way to decide which of a pair of particles is the “normal” one and which is “anti”).
Let’s say that there is a prosperous civilization on Earth, in orbit, and in orbit of the various planets and moons of our solar system. This civilization exists at peace and prosperity for hundreds of thousands or millions of years.
You think at no point will some group say “screw this, we are a religious minority/cult/extremists and we want to go do our own thing, so we will take the habitat we all live on for years and years at a time already, and push it into deep space on a trajectory that will take us to another star system”?
If every 10,000 years a group around a solar system has this idea, then within a million years the whole galaxy is colonized.
Yeah, if you gave me a TARDIS and plopped me into the universe on a quest to find life, I’d probably start around the year 500 billion and look around red dwarf stars.
Do you think that, as humanity expands our technology, we will abandon our motivations to expand and explore?
If so, what do you think would cause that? If not, then why do you think that humanity is unique out of all the species in the universe?
Resources. Metals and other elements, hydrogen as fusion fuel. What makes you sure that they will exist indefinitely with just what they have available in their solar system?
Why is that? Aren’t there solar systems with materials 20,000 ly away?
I assume you mean light speed, not faster than light, here.
They aren’t sending a mission out to our star system. They would be sending out exploitation probes to all star systems.
No, it’s more equivalent to setting up a supply chain that will continue to deliver resources gathered from around the galaxy for the next several million, and from around the universe for some billions.
Right, but why would anyone assume they would skip over all the stars in between? They start by using the resources in their solar system, then the nearby ones, and in short order (compared to the age of the universe), they would be here. You acknowledge that they may exploit the stars near their home system, what makes you think they would stop with that?
That is making the assumption that the goal is to gain intel, which it is not, it is to gain resources.
Yes, we are competition. Resources seem abundant, but they are in fact finite. All it takes is one species to want to continue to grow and expand out of its solar system to do so, so even if they don’t, we will.
As a not entirely ethical, but very pragmatic approach, I would think that we should send out probes that will replicate and exploit the resources in the galaxy and the universe, and not hold back if it detects life, as it is better to remove that life rather than let it evolve into competition over those resources.
That’s just a matter of growth. More population, more need for resources.
Exactly, why do you think that there would be a single homogenous civilization that spans the galaxy when we don’t have a single homogenous civilization here on Earth?
Well, they can populate over some distance without getting near us. But what do you think will stop them at some arbitrary point?
There is not shortage, until there is. The fun thing about exponential growth is that, no matter how vast your resources are, they will eventually not be enough.
And you keep coming back to the assertion that they are personally travelling tens of thousands of light years from their home system, when it’s more just a gradual expansion, that, when viewed in terms of the age of the universe, is actually extremely rapid.
I think that life is common, and intelligence is extremely rare, maybe rare enough that there is only one example for billions and billions of light years around.
No paradox is a true paradox. A paradox arises when two sets of assumptions arrive at different conclusions, and is resolved when either the assumptions are updated, or the logic that is used to draw the conclusion is questioned and improved.
And that’s what the Fermi paradox addresses. The assumption that the universe is old and full of life, and the assumption that if that were the case, we would see them. One (or both) of those assumptions is faulty. But, rather than address either of those assumptions, those wishing to “disprove” the paradox often try to tackle the logic that an intelligent species wouldn’t expand to the limit of its capability. And no matter how many reasons I’ve seen given that a species may not choose to take this route, I’ve never seen a reason given that no species would.
In order to successfully address the logic behind the Fermi paradox, one would have to either demonstrate why humanity cannot expand into the galaxy and eventually the universe, or why we are the only one that could. The only argument that works in that regard is that the great filter is in front of us, it is inevitable and unpredictable, and we are shortly going to smack right into it.
The fact that such a filter is inherently unpredictable does make it unfalsifiable as an argument, so if that’s someone’s view, then I have no evidence against it. However, that view is a bit depressing, and doesn’t lead to interesting discussion.
Never thought that anyone ever really had such a motivation. But, our solar system does boast a bunch of resources and energy, and I’ve yet to see a reason why a species would not want resources and energy.
I see two ways in which humanity spreads its influence across the galaxy.
The first is that we colonize asteroids, and start getting good at creating self sustaining colonies on them. We keep colonizing rocks further and further out, until one day, someone points out that they are actually closer to another star than they are to Sol. Rinse and repeat.
The other is that we decide that we do not want to allow colonization, as that creates a potential for divergence in our civilization and a potential competitor and enemy in the future. So, rather than allow a gradual expansion of colonies, humanity stays in an ever growing shell world or matryoshka star, and sends out excavators to other solar systems to bring back raw materials to continue to grow.
In either case, our presence in the galaxy would become very evident quickly when compared to cosmological timescales.
