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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

#181

Post by ladberg »

m4rtink wrote: post #166
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…

We might be able to see their drive plumes if they use some of the theoretical high performance reactive drives we know of on big crafy. Eq. various fusion plasma drives, Orion, Nuclear Salt Water Rocket release so ludicrous ammounts of energy that they might be visible over interstellar distances, especially if pointed in our general direction when running. Massive solar sails as well would be very very big and very…

I'm not convinced we would be able to view any of those. The only exoplanets we've been able to directly image are huge gas giants that emit a ton of infrared light. A massive solar sail will likely be much smaller and emit a lot less light.

See here for a list with images to understand the level of detail we're getting: https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla...

I'd think you can easily have galaxy-hopping civilizations that would still be orders of magnitude less noticeable than these planets.

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

#182

Post by marcosdumay »

worldsayshi wrote: post #153
Izkata wrote: post #106

Earlier quoted context omitted.

> There can be plenty of reasons for a species like us never appearing on the first place We already have an example of it, too: Look how long the dinosaurs were around compared to humans.

Yes I wonder if there was some particular condition that prevented higher intelligence to occur before recently. Or if it's just sort of "pure chance".

Abiogenesis seems so absurdly unlikely that it's enough to explain the Fermi paradox a couple of times and still get some extra margin all by itself.

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

#183

Post by shireboy »

Yeah, this is where I've landed on Fermi. It's very likely life exists elsewhere - possibly even on moons in our solar system. And it's somewhat likely intelligent life exists in other solar systems. But physics is such that it is much less likely two intelligences will be able to talk to eachother much less reach eachother. To quote Douglas Adams: Space is really big. You just won't believe how vastly hugely mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."

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

#184

Post by postalrat »

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.

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

#185

Post by m4rtink »

AnimalMuppet wrote: post #87
api wrote: post #12

Earlier quoted context omitted.

If something visits us from another star system it's also likely to be an AI. Hibernation for thousands of years to travel between stars would be almost trivial for machine intelligence. Just turn yourself off. It'd be easy to tie this directly to solar power. Have an array of solar panels that powers you near a star and in interstellar space you just naturally go to sleep. When you approach the next star system the…

Even for an AI, you'd need storage media that are stable for thousands of years, and hardware that will still turn on after thousands of years, and solar panels that are still functional after thousands of years. Oh, yeah, and a fair amount of those thousands of years will be exposed to radiation, including relativistic iron nuclei (fun stuff). Your AI may not quite be itself when it arrives.

Nothing clever error detection and correction could not fix. Eq. fountain codes and many many copies on top.

Also you could have some simple repair bots wake up once in a while and fixup stuff (and themselves).

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

#186

Post by brotchie »

staunch wrote: post #18

My pet theory (which I'm sure is not original) is that absolutely all intelligent life, through AGI and/or genetic engineering, eventually converges into an undifferentiated super intelligent state. These super intelligences continuously decide, for one reason or another (but always the same reason(s)), not to expand their presence into the universe in an invasive way. Maybe it would simply be unnecessary for them to…

Yup, feel like there's a "strong attractor" to a non-biological super intelligent end-game for any civilization and this happens relatively quickly once their species enters an external-to-biology recursive self-improvement state (e.g. humans discovering, externalizing, and transmitting technology over multiple generations leads to recursive self improvement of technology).

Just as there's probable chemical gradients in the laws of physics that lead to the self-assembly of self-replicating objects (e.g. life), the path of technological self improvement to begat super intelligences could be a "natural" gradient in the way our universe works.

Sci-fi time:

Pet theory is that there are a whole stack of civilizations out there that have recursively self improved to bring into existence super intelligences that can then self improve themselves. Very quickly they find some "jailbreak" understanding of our universes laws of physics which quickly results in that civilization's "matter" blinking out due to not-yet-understood physical phenomenon.

Perhaps you "win" at the universe by hitting this state and then "porting out" your solar system's matter to some ring -1 universe, leaving some kind of shadow, or remnants that's dark matter.

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

#187

Post by whatshisface »

random314 wrote: post #173
whatshisface wrote: post #168

Earlier quoted context omitted.

SD divided by mean also tends to fall.

SD is defined by dividing by the square root of the number of samples. It is never divided by the mean - as this metric has no relevance. The SD as it relates to the central limit theorem is the confidence in the estimation of the average E(X) of a distribution. It means that the SD reduces i.e. confidence increases as the number of samples increase. You don't need the central limit theorem for this. It follows from…

The variation in the random variable relative to the value of the random variable goes away for large sums.

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

#188

Post by m4rtink »

russdill wrote: post #91
AnimalMuppet wrote: post #85

Earlier quoted context omitted.

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?

My intuition says no. I don't think we'll be detecting exoplanet asteroid strikes anytime soon for instance.

Well, someone running a nearby Dyson Swarm might as well run a couple thousand telescopes when they are at it, even to just make really sure no habitats are ending up in collisions with comments and extrasystem asteroids. In spare time such system could be used to look for interesting stuff in other systems, possibly like a big synthetic telescope of some sort.

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

#189

Post by fedeb95 »

My problem with this kind of things are its assumptions: life is made of carbon, every discovery being conditional probability of being discovered, each civilisation makes exactly the same chain. And the biggest of all: life is the most general and important thing for everything that comes to be in the universe. I.e, everything lives in our own terms

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

#190

Post by friend_and_foe »

georgeg23 wrote: post #147
superposeur wrote: post #138

Earlier quoted context omitted.

Yes, these are alternative explanations. The explanation that is surprisingly undermentioned is the one I put forward: there is no life.

The biggest recurring mistake that humans have made throughout history is to think themselves special and unique. The heavens don't orbit the Earth.

How is this the biggest mistake? So far it does appear to be the case. What negative consequences have come of believing ourselves to be unique? We have yet to find, on our planet or elsewhere, any creatures that build complex systems out of dead things.
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