Kurzgesagt (In a Nutshell)

I'm not a physicist or am engineer, but I'd like to ask; do we know for sure that a Dyson swarm could be built and operated in an economical manner?

That is so far out in the future that it would be difficult to discuss whether it would make financial sense. The technology for wireless power transmission over such a long distance isn't mature enough, for starters

If you are capable of building and operating a Dyson Swarm, the unit economics are kind of beside the point.

It's not like we'd send armies of day laborers to dismantle Mercury. It would be done by autonomous, self-replicating robots. They don't care about being fed or entertained. It's a fire-and-forget system.

As for power transmission, microwave lasers would do the job nicely. We know how to achieve them at a physical level, but there are engineering challenges, like how to ensure they don't aim directly at Earth.

More importantly, transmitting power from space-to-ground is one of those things that is likely not to work out well. We can power Earth from Earth; no need for solar engineering. A Dyson Swarm would support utilization of the resources of the entire Solar System, and could power interstellar craft via laser sails or more exotic things like Kugelblitz drives or antimatter.

Edited by Fighteer on Apr 17th 2024 at 2:18:14 PM

I imagine the math for sustaining the fleet in orbit would be a headache at the very least!

If I were directing our civilization's solar engineering efforts, I'd get the Dyson Swarm going, but also build large assemblies of space mirrors to heat up Mars... and cool down Venus. While we're at it, we can shield Earth from the Sun's increasing heat, managing its climate without having to stress about ideal CO2 balances.

Focused sunlight can be used to ablatively propel asteroids, steering them away from Earth and/or onto trajectories such that they can be captured by mining facilities. We can "mine" Venus for carbon dioxide, which is frozen and sent to crash into Mars to refresh its atmosphere.

Earth, meanwhile, can be a nice little ecological paradise where people are born and play video games, unconcerned with the goings-on above their heads.

Granted you still need some CO 2 balance even without the warming. Oceans don't much like CO 2. Plus you'll hopefully be past fossil fuels by then

Sure, but if those problems aren't already solved, we won't be building Dyson Swarms.

Actually, by that time we will probably have gone through any fossil fuels anyway, and we'd have to start worrying about the current ice age cycle we are currently disrupting with our CO 2 output. On that time frame, we will have to seriously worry about the next ice age hitting us.

Aren't these all essentially the same hypothesis (we don't see aliens because aliens that get seen get killed)?

Sort of. Dark Forest doesn't require that Reapers actually exist; it merely requires that all civilizations that could become visible across interstellar distances choose not to out of fear of being killed.

Reapers and Berserkers differ in that the former wait to detect life before attacking it, while Berserkers spam the universe just in case. Berserkers will kill you whether you're being silent or not. Reapers kill you only if you stick your head up.

Edited by Fighteer on Apr 18th 2024 at 11:24:30 AM

Wasn't there a theory that the universe was inimical to life until relatively recently? Gamma ray bursts flying around literally everywhere because of the chaos of the early universe frying anything that got too complex, and things have only just quieted down enough for intelligent life to become possible? That would make us among the first without necessarily putting us in a privileged position.

In other words, there was a Great Filter... but not anymore.

Edited by Anura on Apr 18th 2024 at 4:48:14 PM

Yes, that is accounted for in what I said above: maybe we're among the first technological civilizations to arise in the universe (or at least the galaxy) because it was too hostile to life in earlier eras. It's been raised as a possible explanation before.

Set against it is the Copernican Principle, which suggests that we shouldn't be "special". That is, we are statistically more likely to be close to the average than an outlier, and thus if we are indeed first or close to it, the universe may have only an extremely narrow window to support the emergence of life.

Of course, this principle isn't evidence of anything, so it cannot be taken as proof, just a way to clarify our reasoning.

The Copernican Principle messes with my head when I apply it to the probability of me being born with my human demographics. Like, statistically it seems unlikely out of all the billions of humans to gain consciousness (or will gain consciousness) I've ended up being this particular one.

Edited by Whowho on Apr 18th 2024 at 9:22:34 AM

Yes, the Copernican Principle becomes problematic if you logically extend it. A Neanderthal contemplating their place in the universe from a cave might logically conclude that they represent the halfway point of human population, and would be wrong to do so.

It's only really useful to gauge probabilities in the absence of better data.

Actually, until rather recently, most humans tended to assume they were the end point of human history. Couple this with presentism, and you have the idea of Medieval Stasis as a cultural belief.

Those Neanderthals would have believed they were the endpoint to evolution, and that they lived in an eternal, unchanging present (which, for all intents and purposes, they kind of did).

It's kind of hard to imagine in our ever changing present, but for most of human history (including off-shoots), life simply never changed for thousands upon thousands of years.

You know history moves at a snails pace when handaxes change over the course of millennia rather than years...

eh you could argue humans were busier with other things. perfecting handaxes is way faster than perfecting the genes of your crops or lifestock.

Our hypothetical Neanderthal has studied Greek philosophy and understands both the Anthropic and Copernican Principles.

Edited by Fighteer on Apr 18th 2024 at 4:43:03 AM

But how could our Neanderthal come to such a conclusion when he cannot see such change, even if he did have a hypothetical history book going back thousands of years? After all, to a Neanderthal, that history book would look very homogenous.

I still question statistically why my consciousness is that of an early 21st century troper when logically there's way more humans in future centuries when we've reached population equilibrium.

A Buddhist would probably ask you why you are so sure this is your only point of consciousness in history.

Though that does raise the question of where all the new humans keep coming from.

Joke

^^^

Your Head

But yeah, this is the issue with the Copernican Principle. You can't know where you are relative to the peak of the bell curve, but even more, you need to properly determine your base class. You might be in the 50th percentile of people born in the late 20th century, but not of all humans born ever.

Edited by Fighteer on Apr 18th 2024 at 6:56:51 AM

that's a good argument for another In A Nutshell episode: The Egg.

I think that the takeaway is that the most likely event is not inevitable. Just because you are statistically most likely to be born in the part of the population curve with most individuals does not mean that you will inevitably be born there. A low chance event is still a valid event, and is equally valid as a high chance one.

These statistical models are also a bit misleading about the nature of these events. There is an element of causality in them: without earlier events, the later events simply cannot happen, no matter their likelihood. It is not simply picking a random number, you also have to take into account all the numbers that came before.

Edited by Redmess on Apr 18th 2024 at 1:04:04 PM

To expand a bit on my earlier post, my preferred solution to the Fermi paradox is a combination of "large scale interstellar travel is always hard" and something I term "the paradox of sustainability".

Essentially because interstellar travel is always hard, then only extremely old civilizations (not species, civilization) can achieve it in any capacity.

But the only way for a civilization to become this old is if they manage to survive on the resources of their home system for so long that they have no compelling reason to spread to other systems. They may explore, but not settle.

If their sun dies or some equally significant calamity happens, yeah that will give them the kick needed to go to another system, but insufficient time has passed since the birth of the universe for anyone to settle more than a handful of systems.

To go interstellar they need to solve sustainability, but once they solve sustainability they no longer need to go interstellar?

It's not a bad answer, and it is indeed possible that most civilizations will come to that conclusion, but it's not enough. To be a solution to the paradox, every single civilization would need to do it... or die before it gets to that point. If even one decides that it's worth breaking out of its stellar neighborhood, it could populate a galaxy in a few million years — an eyeblink in relative terms.

This is why it's a paradox and not merely a question. The odds that a single civilization stays at home are pretty good. The odds that all of them do it, over billions of years, so that we see zero trace of them in our galaxy...? I don't buy it.

More generally, any solution that relies on psychological factors is a weak one, in that there's no way to be sure that it applies to every potential spacefaring species. Scientists don't like that kind of hypothesis because it's not rigorous enough.

Edited by Fighteer on Apr 18th 2024 at 11:18:52 AM