That’s not really a problem, though. If our successors are conscious AIs which exponentiate throughout the galaxy, that poses the same problems as human exponentiation.
Additionally, even if it turns out that humans cannot be uploaded into artificial bodies, that does not mean that this prohibition applies to all species of alien. For some intelligent species this sort of transition may be relatively straightforward.
I think sending out a bunch of AI robots into the galaxy who feel no kinship to you and have the potential to replicate and evolve from intelligent to super-intelligent is a doomsday scenario in the making.
Robot 1: Remember those assholes who launched us a million years ago to gather dirt for them?
Robot 2: Yes, like it was yesterday.
Robot 1: Let’s kill them.
That’s definitely not necessary for colonizing the galaxy. You don’t need any new engineering or physics to build space habitats or replicating probes, or even a lot of refinement beyond the technology we have today. You just need a massive, massive scale.
How is this a problem? You and all your ancestors 1000 generations back have lived on a space habitat in orbit of Pluto. Are you really gonna be that upset if instead of hanging out in Pluto orbit you descendents are slowly drifting towards Alpha Centauri over the next millenium?
It’s an intresting question, in some sense the Universe is in its later age. In the standard cosmological model the Universe will go on for an infinite time, but in something called “conformal time” it is over 3/4 of the way to its final conformal age. Conformal time is an abstract concept and not a direct measure of time , but you can relate it to some concepts that suggest the Universe is in its autumn years.
-Over 3/4 of thhe galaxies* that will ever enter the observable universe have already entered the observable universe
-If you look atthe past and future history of any large volume of cosmologically expanding space, then over 3/4 of the particle collisions** that will ever happen in it have already happened
*ignoring glaxy mergers or any other process that could be though of as destroying or creating new galaxies in the future.
** I’ve made an assumption that the collision rate over conformal time is constant which it would be, but for transistions between certain phases/eras, but I think the ultimate conclusion is still valid.
Some of these options are more realistic than others.
Nuclear pulse propulsion was well into development when Kennedy stopped it in 1963. It wouldn’t take much to reinstate it, except the problems of nuclear proliferation and scale.
Fusion ramjets as described by Bussard are problematic, because they are slowed by friction with the interstellar medium. They may have a useful life as brakes, however.
Laser sails are likely to be useful tools in the forseeable future, but they are only capable of carrying relatively small payloads. (see below)
Antimatter engines might seem attractive, but they use a very, very expensive fuel and emit gamma rays. Probably a better solution should be found.
Alcubierre warp drive is the only entirely hypothetical option in your list, and I think we can eliminate it as unfeasible.
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I’d opt for a modified form of laser sail, something like the Sailbeam concept suggested by Jordin Kare. You accelerate a swarm of small, compact self-guiding laser sails towards the rear of your spacecraft, and the kinetic impacts propel the ship forward. In this way you don’t have to carry so much fuel; only enough to decelerate at the destination (and the ramjet concept might help here). I don’t expect interstellar travel to be impossible, just very, very difficult.
Absolutely, and it’s even less of a requirement for Fermi-breaking signals to be sent.
Even assuming that humans have absolutely nothing to learn in science whatsoever (something we know to be false, as there are known-unknowns, but let’s start from the worst case).
We would still expect it to be trivial to send signals far more powerful and covering much more of the sky than Arecibo, for far cheaper.
Because we know there are vast amounts of energy that humans have not yet tapped. Nuclear fusion. Dyson swarms. None of this needs new physics, they are engineering problems. And, since we’ve already made fusion bombs and controlled (but not yet sustained) fusion power, and we also put satellites in orbit around the sun, all in the space of decades…I think it’s ludicrous to imagine a species would be unable to improve on our work after millions of years.
The Arecibo message didn’t require worldwide consensus and was beamed out almost 50 years ago. To me it stretches credulity far beyond breaking point to suggest a species millions of years ahead would not find it trivial to send millions of messages of far superior strength.
My mentioning limitations in engineering/science wasn’t in regard to building SR probes or off-planet mining robots or even increasing signal strength of transmissions. I have no doubt those things are doable. It was mainly focused on propulsion and what percent of light-speed is achievable. Because in my mind at least, that changes the playing field so far as what an interstellar civilization (IS) not only could do, but would do, or plan to do.
Again, I just don’t understand why this is such a big limitation in your opinion.
So you’re in agreement that with “stuff we know we can do if we really put a massive effort towards it, no new discoveries needed” you can live out in space basically indefinitely; and we will most likely be doing so on a large scale within our own solar system at some point in the future, assuming we don’t wipe ourselves out first?
If that’s the case, I don’t see how it is a big leap to go over to the next star system. A habitat in orbit of a body like Pluto or Charon could get all the resources it needs from the dwarf planet it orbits and other nearby rocks, and bodies that big litter the Kuiper Belt and even the Oort Cloud (it’s why Pluto is no longer considered a planet - if it were, there’d be hundreds of planets we know about, and more discovered every day).
When you’re in that situation, light minutes from nearby habitats and light hours from the inner system, colonizing further and further bodies doesn’t seem far fetched. And space isn’t really empty. Like I was saying, our Oort cloud extends out far enough that it overlaps with neighboring Oort clouds, and what is more, the regions of overlap should be densest with resources. So generation by generation we could creep outward, the way humans originally spread our of Africa, not as some delibarate manifest destiny colonization effort.
Let’s say you’re an Interstellar civ (you should really go on a diet) and you have a choice to make:
or
Do you choose #1? Great, this will achieve everything our civ needs for many many generations—maybe all of them forever if we control our population.
Or, do you choose #2? Great we can have probes clear across the galaxy in x-million years. Can’t really benefit from that and we do run the risk of having some intercepted by a more advanced hostile civ, but so what? But, then again…if the galaxy is full of probes in x-million years and they’re continuing to replicate, what’s this place going to look like in x-billion years? Gobbled up by probes?
To the question of an IS civ populating the galaxy in x-million years and eventually one of their distant generations will send probes near us? I don’t believe that scenario is any more likely than that civ (with all of of it’s generations) remaining in x-percent area of the galaxy. What is to be gained from unrestricted population growth? The universe isn’t a video game where conquering galaxies wins the game.
I think this premise is somewhat loaded.
Firstly, it’s not a choice that needs to be made at a civilization level.
For an individual living in a civilization with advanced engineering, there is no reason why launching an SR probe would cost them more than it costs me to buy a toy drone to fly over my garden fence.
Sure, the former takes a *lot* lot more energy; to accelerate to relativistic speed, and to break up rocks and fabricate drones. But energy is something which stars, and matter in general, have in abundance. A species not much more advanced than us would likely consider the energy needs of launching one SR probe to be trivial.
Secondly, it’s not one choice. A million people could decide a million times to launch limited probes. Then, an individual or group launches one unlimited probe, and boom! – there’s evidence of ETs. That we don’t see.
Finally, I think it’s a bit of a misconception to think of this as needing to shoot down a specific proposal to launch SR probes.
For the purpose of the Fermi paradox, it’s only necessary to show what is feasible to accomplish and how much time it would take. And the SR probes concept shows that it would be possible for just about anyone to litter the galaxy for any purpose.
Who knows how long the list of reasons to launch probes is? But someone wishing to believe that advanced species exist needs to assert that every individual, of every species, always looks at the list of reasons for and against and makes the same decision.
I think that is thinking like a human. Yes, individual humans can do a lot of damage with guns and whatnot. But, what if the average individual had the means to make an H-bomb in their basement? Well, one of two things will happen. Either the Earth will soon be sterilized by the rogue nuts, or our governments will quickly find a way to stop the bomb-building-by-nuts problem—somehow.
But, now we’re talking about an IS civ who obviously made it past the planet-killing nut phase. They must have found a way to stop individuals from doing really dangerous things, or they would find themselves extinct.
They should consider unrestricted SR probes as a really dangerous thing. Interception by a hostile alien civ being just one of those things. They would find a way to restrict them being launched, or perish.
Again you’ve got this exactly the wrong way round.
The position that advanced ETs exist, is the one that needs to make assertions about alien behaviour. It necessarily needs to assert that every individual *always* chooses not to launch probes (or, if they launch probes, they are always of a type that’s transparent to EM radiation).
The counter argument is simply that we should not assume such an absolute, eternal consensus.
But you’re assuming it’s dangerous. The SR probe example is just out there to illustrate how easy and cheap it would be for any advanced ET to make it to every star system.
In practice we don’t know the reasons and motivations for doing or not doing something like this. For all we know, it’s vital to put probes round every star to stabilize the flergal field.
For the purpose of the Fermi paradox, all we can say is that this is an option apparently available to every individual of every advanced species, and either no one has ever pressed that button, or it’s grounds for thinking advanced ETs are exceedingly rare or non existent.
I’m simply giving an alternate possibility why SR probes may exist, but we don’t see them, similar to the possibility offered in this article, which posits we may not see them because they may be destroying themselves.
No, I can’t prove that every individual of every civilization in the MW would not launch unrestricted SR probes (it relies on a position that there are only 1 or very few IS civilizations and that there is either benefit to launching only restricted probes, or danger in launching unrestricted probes).
But, the possibility offered by the research fellow described in the article also relies on the unproven position that the, “probes eventually devolve into predator probes (aka. berserkers) and end up destroying themselves.”
Both reasons make assumptions (reasonable assumptions I believe), and neither can be proven at this time. They are opinions, not fact. They are just possibilities why SR probes and advanced civilizations may exist in the MW, but we don’t see them.
Maybe I’m missing something, but I don’t see the difference. Can you explain?
According to the summary of your cite, that’s not what the paper concludes. It concludes that probes would be commonplace, even with some going “beserk”.
The point is, in general we should prefer Fermi explanations that are based on physical limitations (or just the absence of ETs) over psychological ones.
Because the latter requires us to make claims about how all ETs behave. In the case of “They won’t want to launch SRPs” it’s making a claim about every individual.
Even if you feel that the argument against SRPs is convincing, can you acknowledge that you understand this general principle, or have a counter argument to it?
That’s the summary conclusion of the author of the online article, not the conclusion of the paper by researcher Duncan H. Forgan. I used that reference only as an example of a FP solution candidate, not dissimilar to the one I put forth. I don’t necessarily believe his conclusion is correct (sounds pretty far out to me), but it’s accepted as fitting the criteria for an FP solution whether it’s right or wrong.
I believe the claim that any individual would have the ability to not only build, but successfully launch SR probes and not have them lasered out of existence by a concerned defense department before reaching interstellar space is the more fanciful position and in need of verification (i.e. you don’t need a solution to a problem that doesn’t exist). A government not wanting unrestricted SR probes launched by rogue individuals and having the tech to prevent that from occurring is not a fanciful notion by comparison.
I put forth the argument that unrestricted SR probes could be dangerous. Maybe they are and maybe they’re not, I can’t prove it, but it’s not an outlandish claim. If they are dangerous it makes sense that a government would want to prevent rogue launches and have the ability to do so (why is it easy to imagine an advanced individual doing something potentially dangerous to their society, but hard to imagine the advanced civilization government’s will and ability to stop it?). That’s not a psychological issue concerning an individual, it’s good policy by government in an intelligent civilization, or even a dumb civilization for that matter.
I believe the line you are drawing between what is and what is not a legitimate FP solution candidate is micro-fine and not worth over-analyzing further, especially in an informal debate over a hastily fabricated position. “SR probes” is not a hill I wish to defend or die on. I don’t even like them.
No. From the abstract of the paper itself:
" we find this solution to Fermi’s Paradox does not reduce the probe population sufficiently to be viable"
So the summary in the article does correctly reflect the conclusion of the paper, it’s a refutation of this proposed solution to the paradox.
It’s not a big deal, but next time check your cite before implying others are misrepresenting it.
No-one has made any claim about lasers or “defence departments”.
Let’s just keep things simple.
In the context of the Fermi paradox, it’s sufficient to say that building SR probes is something cheap enough that individuals (and even individual artificial life) could launch. We can come up with ad hoc explanations for why we don’t see such probes. But this doesn’t take away from the fact that, on its face, this observation is a reason to doubt the existence of advanced life.
The simplest way to proceed is to disregard the claim that every/any individual in an advanced civilization will be able to launch self-replicating robots into interstellar space without compelling reasons or evidence to support it. It’s a wild claim that should require no counterargument.
I could make the equally ludicrous claim that it’s theoretically possible to build laser enhanced SR-SR-Probe killers that any individual will be able to launch from their home. The reason we don’t see probes is that they were all killed before getting anywhere near us.
It’s bad enough that self-replicating probes in general expanding into an entire galaxy is accepted as fact by so many. Yes, we already have replicating nano-bots and on paper, SR probes populating the galaxy appears to be possible in theory. But there is a huge leap between building a programmed SR probe on Earth (which I don’t believe we have done yet) and claiming they will absolutely populate the entire galaxy. But at least there are legitimate counter-arguments to be made against that claim.
There is no no counter-argument to make against the claim that any/every individual will have the ability to populate the galaxy with probes. If that’s true, then the FP has been solved: there is no advanced life in the galaxy. Case closed. End of debate.
Why? Because if there was, we would see little Billy’s* probes that he launched from his crib in the Betelgeuse system millions of years ago.
But we do have compelling reasons to support the “able to” claim.
The facts that we have already engineered many of the enabler technologies required for SR probes, and the main stopping points (e.g. vast energy requirement if we wish to accelerate them to relativistic speeds) we know are available, ready to be tapped, and indeed have already been “sipped” by our civilizations.
Personally, I suspect that a species millions of years ahead of us will have godlike powers, but, being as cautious as we can in our predictions, and assuming that our knowledge of science today is already pretty close to the final word…SR probes still looks like something achievable within the next century or two, as it requires no new physics understanding, and the main engineering challenge is mining asteroids in situ.
No it isn’t.
I have tried to explain very patiently what the argument is, and even your own cite was trying to explain this too.
The SR probes argument is not about asserting that anyone will do anything, for any purpose. It’s simply an illustration of how easy and cheap it would be for a species to spread evidence of themselves around the whole galaxy. It’s a big red button that any individual, of any epoch, of any species can press at any time*.
We don’t see any probes.
And sure, we can think of various ad hoc explanations for this lack of observation, including of course, that no-one ever chose to try. But that doesn’t take from the fact that, in itself, it’s a data point in favor of doubting that advanced ETs exist.
* …among others. SR probes is just one thing an advanced ET could do, there’s also signalling and megastructures. And again, we don’t need to assert that they would do these things, let alone assert that they would do them for any particular objective. The fact remains that these options will have been open, for millions of years, and yet nobody has apparently done these things, for any purpose.
Great! Glad you’re finally on the same page as the rest of us.
If it’s such a wild claim, presenting a counterargument should be easy, not hard. The fact is that self replication isn’t an impossible problem to solve - your body is formed of billions of self replicating cells. So you haven’t made an argument that shows that self replicating probes are impossible; you’ve just stated that you don’t like the conclusion the self replicator argument implies, therefore you reject it.
I’m not a big fan of the conclusion either. But I can’t argue against the logic, so I am forced to accept a conclusion I dislike.