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The Fermi paradox revisited: Technosignatures and the contact era

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Re: The Fermi paradox revisited: Technosignatures and the contact era

#271

Post by antonvs »

cortic wrote: post #68
marcosdumay wrote: post #43

Earlier quoted context omitted.

> because otherwise the reason we're free to exist is because species like us always wipe themselves out before they spread That's a complete non-sequitur. There can be plenty of reasons for a species like us never appearing on the first place, and they are way more reasonable than postulating that life like us always destroy itself.

We are actually running out of places in our history to fit a great filter. Most of the events in our evolution seem probable, even inevitable. In fact the only place IMO that's really left is the emergence of the first self replicating RNA molecule. But even that seems too probable to be a great filter. And if its not behind us, it has to be in-front of us or we are under a great misapprehension about the nature of…

> We are actually running out of places in our history to fit a great filter.

Other than the obvious, which is the utter physical, technological, economic, political, biological, and statistical impracticality of interstellar colonization.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#272

Post by AnimalMuppet »

hackernudes wrote: post #112
damontal wrote: post #96

Earlier quoted context omitted.

or we are in a simulation

That doesn't really solve the problem because the simulation is (apparently) big enough to allow life to evolve. Why couldn't life evolve multiple times in a simulation? Isn't the argument about simulation more about pondering the question "what is the fundamental nature of reality?", not "why is there life?". If you say that some beings are interfering with our simulation (either designing life, or preventing other…

It's another word for God even without interfering. There's still the Creator(s).

Re: The Fermi paradox revisited: Technosignatures and the contact era

#273

Post by yreg »

cartercwchen wrote: post #24

I prefer the Dark Forest interpretation of the Fermi Paradox: https://en.wikipedia.org/wiki/Dark_forest_hypothesis

If there was an advanced civ that fears competition, waiting for a random radio signal and then venturing on a crusade would not be the smart strategy.

You could instead launch relativistic kill missiles (pieces of rock) at all the planets in the galaxy before other civs emerge.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#274

Post by nobody9999 »

AlbertCory wrote: post #176
credit_guy wrote: post #149

The Fermi paradox is good for a nice chat at a party. But it's not a paradox at all. Imagine there's an alien civilization in our galactic neighbor Proxima Centauri. How would we know they are there? To make it more plausible. Let's say we figure out a way to send a space probe to Proxima Centauri. How do we communicate with that probe? Easy, you say, just like we communicate with the Voyagers: they point a reasonabl…

Well said. The "Drake Equation" is complete and utter garbage. There is no such thing as a "probability" of any of those terms, in the way we normally understand probability, i.e. dice or card games. That said, there probably are intelligent civilizations somewhere in the universe, but we have that pesky problem of distance and the speed of light, as you said. People like to imagine that eventually civilizations find…

>Well said. The "Drake Equation" is complete and utter garbage. There is no such thing as a "probability" of any of those terms, in the way we normally understand probability, i.e. dice or card games.

I'd say that any result you try to pull from the Drake Equation is "complete and utter garbage."

The value in the Drake Equation isn't in any calculation we might do with it. Rather, it's a way to categorize both the variables necessary for the development of technological civilizations, and our ignorance as to both the value of such variables and variables we don't even know exist (which can be added as we learn more).

In fact, the Drake equation[0] was never intended to be useful as an equation:

   The equation was formulated in 1961 by Frank Drake, not for purposes of 
   quantifying the number of civilizations, but as a way to stimulate scientific 
   dialogue at the first scientific meeting on the search for extraterrestrial 
   intelligence (SETI)
[0] https://en.wikipedia.org/wiki/Drake_equation

Re: The Fermi paradox revisited: Technosignatures and the contact era

#275

Post by m4rtink »

YurgenJurgensen wrote: post #41
bnralt wrote: post #15

Earlier quoted context omitted.

I've been wondering what the advantage of von Neumann probes are. Once you have the ability to autonomously construct probes, it seems like it would be easier and faster to mass produce them in one solar system and send them directly to their destinations. For instance, with a von Neumann probe you have to have probes with additional mass for self-replication, have it accelerate halfway to point A, decelerate halfway…

If the probes don't have replication devices in them, what are they doing? The main point of the von-Neumann strategy is that if you don't build a self-replicating hegemonic swarm object, someone else will (whether that be an alien or merely someone else in your own society), and despite what science fiction movies would like to have you believe, you don't win in a war against the Replicators.

You do if yours are better. ;-)

Re: The Fermi paradox revisited: Technosignatures and the contact era

#276

Post by withinboredom »

yreg wrote: post #254
withinboredom wrote: post #244

Earlier quoted context omitted.

And what if we broadcast and whomever hears us wants us dead? Maybe it’s so quiet because to be loud results in death of the entire civilization.

If you are an advanced civ that fears new competition, you don't wait for hearing random radio transmissions. You build replicating factories to build relativistic kill missiles and preemptively destroy all the planets in the galaxy.

Hmm maybe. If anything, I don’t think it would be killing for competition. Killing a planet is “easy” if you can expend the energy. The risk of accidentally offending another civilization is much easier, offending them to the point of them wanting to wipe you out isn’t that much harder (see Earth History). Thus, it almost makes sense to just wipe out any civilization preemptively.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#277

Post by DesiLurker »

AnimalMuppet wrote: post #85
actionfromafar wrote: post #66

Earlier quoted context omitted.

I think it can be done cheaper than that, and with technology we have access to. Detonate a handful of large hydrogen bombs in deep space, set apart by minutes. Say hello to our fellow Aliens.

How far away do you think such a thing could be detected? Say someone set off a 100 megaton nuke in space within the Centauri star system. Could we detect it?

its inverse square falloff for radio energy dissipation so I'd say it goes away really really quickly. also you have the problem of overcoming Sun's 'blaring' background signal unless you took your signal generator and placed it outside of oort cloud or further.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#278

Post by nobody9999 »

postalrat wrote: post #184
credit_guy wrote: post #149

The Fermi paradox is good for a nice chat at a party. But it's not a paradox at all. Imagine there's an alien civilization in our galactic neighbor Proxima Centauri. How would we know they are there? To make it more plausible. Let's say we figure out a way to send a space probe to Proxima Centauri. How do we communicate with that probe? Easy, you say, just like we communicate with the Voyagers: they point a reasonabl…

The paradox is that the our solar system should have been visited. But so we haven't been able to detect anything. It's much closer than the centauri system.

>The paradox is that the our solar system should have been visited. But so we haven't been able to detect anything.

>It's much closer than the centauri system.

That assumes there have been other(s) technological civilizations in our galaxy. Which isn't necessarily the case. We may well (or not) be one of the first space faring (for some values of that term) civilizations in our (part of) the galaxy.

A recent discussion about this can be found here[0] (PBS Space Time episode from 9 November 2022).

[0] https://www.youtube.com/watch?v=uTrFAY3LUNw

Re: The Fermi paradox revisited: Technosignatures and the contact era

#279

Post by pmontra »

bottled_poe wrote: post #207
pmontra wrote: post #198

Earlier quoted context omitted.

Even with FTL you have to know where to go. Let's say you do 100 solar systems per year (going somewhere close to the star and some local jumps to look around.) There are 100 billion stars in the Milky Way. It takes a billion years to sequentially scan the galaxy. Optimizations in the search algorithm to cut that number down to 100 years are left as an exercise ;-)

Branching factor of two means around 30 hops to visit every star.

2^30 probes at the final hop. Maybe those FTL ships will turn out to be cheap to build like in Vance's Demon Princes novels.

Re: The Fermi paradox revisited: Technosignatures and the contact era

#280

Post by m4rtink »

YurgenJurgensen wrote: post #76
bnralt wrote: post #63

Earlier quoted context omitted.

If you want to restrict yourself to the earth's crust, that'd still be ~5,000,000,000,000 kilos of iron you could use per star, or 1,500,000 Saturn V's. And that's just using one planet. Sure, there are rarer metals. But I'm not seeing evidence that the solar system wouldn't have enough of them, and mass mining and manufacturing seems like an far easier way to handle them than individual probes (the probe would have…

The fact that you're talking about Saturn Vs and landing on planets and taking off again shows that you're considering the wrong paradigm entirely. If you're landing on planets you're already doing it wrong. Atmosphere and gravity wells are the enemy. Remember, even the non-self-replicating probe still needs to be self-repairing, since in your scenario it has to last for probably a million years' worth of radiation a…

Atmosphere can still be handy! You can use it for aerocapture or aerobraking or aerocapture, massively reducing delta-v for trips to that body.

Same with gravity - useful for gravitational slingshot maneuvers or high trust burns making use of the Oberth effect.

You might even land once on the planet, so that your von-neumans can shoot it into space in chunks for further processing.

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