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Grabby Aliens (2021)

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Re: Grabby Aliens (2021)

#81

Post by exe34 »

throwawayqqq11 wrote: post #53
Matt_Mahgerfteh wrote: post #35

Earlier quoted context omitted.

Yeah, it's like we're playing cosmic detective trying to figure out if there's anyone else out there in the universe. The fact that we haven't seen any clear signs of alien civilizations doing their thing is kind of mind-boggling. It's like, are they just really subtle about it, or are we just super early to the party?

When you mine asteroids in orbit on a large scale around your star, the released dust/debris would form an IR halo around the star that would be very easy to detect and reveal your presence but we dont see any of it. So, early humans it propably is.

Would you pollute your environment with missiles at orbital speed? I suppose given our stellar stewardship of the atmosphere, maybe they're like us.

Re: Grabby Aliens (2021)

#82

Post by exe34 »

cryptonector wrote: post #79
XorNot wrote: post #65

Earlier quoted context omitted.

Rather depends on other factors though: you can perfectly well run an interstellar empire with very long communication times and people going into suspended animation for transit. Control strategy simply has to adapt accordingly: i.e. a message probably comes with a fleet sufficient to ensure its obeyed. This was one of the ideas in the Doom novelizations: that the aliens had spent so long travelling that there was l…

> you can perfectly well run an interstellar empire with very long communication times and people going into suspended animation for transit. If travel times are orders of magnitude longer than lifetimes, then you will tend to lose civilizational cohesion. > Control strategy simply has to adapt accordingly: i.e. a message probably comes with a fleet sufficient to ensure its obeyed. What even is the point? The message…

The fleet carries the message.

Of course, there's a fair chance that by the time the fleet gets there, the colony is long dead, or has advanced in weaponry in a different but overwhelming direction, so they just barely notice the little flash way out past their oort cloud.

Re: Grabby Aliens (2021)

#83

Post by brazzy »

eschaton wrote: post #50
eightysixfour wrote: post #43

> While the current date is 13.8 billion years after the Big Bang, the average star will last over five trillion years. That does not seem right. Isn't the lifespan of a star between 100m and 100b years or so?

I think it depends on what you mean by “last,” a star might “last” even longer than 5×10^12 years before the last component nucleons of its remnant evaporate. If you consider how long a star lasts to be how long it emits around the same amount of energy until becoming another class of object the time will be shorter. Sol will grow large and red in another 4×10^9 years or so, then after that phase it’ll leave a stella…

No, it doesn't depend on any such interpretation. The key word is "average". A majority of stars are red dwarves, and those do in fact last for trillions of years without significant change.

Re: Grabby Aliens (2021)

#84

Post by brazzy »

This kind of thing always has the same weakness: it's extrapolating from a sample size of one. It of course tries to account for that by adding large error margins based on what we know, but for some of them it's pure guesswork that could easily wrong.

Re: Grabby Aliens (2021)

#85

Post by brazzy »

GavinB wrote: post #10

This is a compelling theory, especially the implication that humans are early. I do wonder whether we should see the evidence of spheres of growing alien influence out in the stars, but instead we see a highly uniform universe in all directions. This would indicate a few possibilities: 1. Expanding alien civilizations are relatively low impact and don't collect all of the energy of stars in ways that are visible to o…

My money is on option 2 with the key factor being that complex, intelligent life takes a long time to develop. Our empirical data (of sample size one) indicates that it takes multiple billions of years to go from single celled life to even quite simple multi-celled life. If we got lucky with that, the average could easily be longer than the age of the universe.

Re: Grabby Aliens (2021)

#86

Post by XorNot »

lostemptations5 wrote: post #77
XorNot wrote: post #74

Earlier quoted context omitted.

I do keep hoping we get lucky in my lifetime and a massive, water bearing comet with slam into Mars and jumpstart the terraforming. Watching a planet which could retain water go from "nothing to oceans" would be amazing.

Evidence suggests Mars had oceans before and they just evaporated due to the thin atmosphere and non-existant magnetic field no? I'm not sure how that would get solved without some active technological solution by humans let's say.

Over a timespan of hundreds of thousands of years.

Which is short in geological terms, but an eternity in technological ones. We would have plenty of time to solve that problem.

Re: Grabby Aliens (2021)

#87

Post by distracted_boy »

fouc wrote: post #2

What I found most interesting about this model was the implication that humans are possibly one of the earliest sentient spacefaring species to have appeared so far. Which explains why we haven't seen any other signs of extraterrestrial intelligence yet.

We have seen signs, they were called UFOs but are called UAPs now, at least by the US government. People have tried coming forward over the years and talk about the subject, but was met with ridicule.

I suggest googling David Grusch to read about the whistleblower from inside US intelligence services. Also search for “Navy Rear Admiral Tim Gallaudet ufo” and you’ll find additional comments.

This is the greatest coverup in human history.

Re: Grabby Aliens (2021)

#88

Post by XorNot »

cryptonector wrote: post #79
XorNot wrote: post #65

Earlier quoted context omitted.

Rather depends on other factors though: you can perfectly well run an interstellar empire with very long communication times and people going into suspended animation for transit. Control strategy simply has to adapt accordingly: i.e. a message probably comes with a fleet sufficient to ensure its obeyed. This was one of the ideas in the Doom novelizations: that the aliens had spent so long travelling that there was l…

> you can perfectly well run an interstellar empire with very long communication times and people going into suspended animation for transit. If travel times are orders of magnitude longer than lifetimes, then you will tend to lose civilizational cohesion. > Control strategy simply has to adapt accordingly: i.e. a message probably comes with a fleet sufficient to ensure its obeyed. What even is the point? The message…

Ascribing limited-lifespan human motivations to potentially infinite lifespan non-human intelligence is the core mistake here though.

You look at running an empire with hundreds of years of message delay as pointless, they may view it as totally necessary. After all - if from your subjective opinion you blink and you're in another star system (hundreds of years later), then are you even worried about that time difference, or are you worried about whether they're still flying the right flags when you get there?

(you can imagine a similar arrangement of times working out for social relationships over such timespans - duration might not much matter if everyone sort of agrees they'll wake up for X amount of subjective time before meeting up again in person).

Re: Grabby Aliens (2021)

#89

Post by willis936 »

GavinB wrote: post #10

This is a compelling theory, especially the implication that humans are early. I do wonder whether we should see the evidence of spheres of growing alien influence out in the stars, but instead we see a highly uniform universe in all directions. This would indicate a few possibilities: 1. Expanding alien civilizations are relatively low impact and don't collect all of the energy of stars in ways that are visible to o…

The problem with option 3 is that even a small drop below light speed becomes a large multiplier when looking at galactic and intergalactic distances. Let's say you can manage 0.5 c (pushing far beyond any current physical understanding of what is possible), that means we would have up to a 40,000 year heads up on an approaching galactic civilization. Even if it was 0.9c we would have up to 8,000 years notice. Even with something crazy like direct antimatter - matter conversion the amount of energy to bring a ship to that kind of speed would be a gigantic beacon in the night sky. Barring science fiction we can be relatively confident none are on their way right now.

Re: Grabby Aliens (2021)

#90

Post by Udo »

Arch485 wrote: post #8

I might be missing something here, but why would alien (or any) civilizations continually expand at a constant rate? While I'm not an expert, it appears that by observing life on Earth (not just humans), groups of living things do not expand linearly, and eventually hit an upper limit (this happens at all scales, from colonies of bacteria to entire civilizations). Who's to say that other "loud" aliens haven't already…

> Who's to say that other "loud" aliens haven't already expanded and begun spacefaring, but simply are not expanding out to where we are?

By definition if they're loud and we can't see them, they're not within the volume of our visible universe.

> I might be missing something here, but why would alien (or any) civilizations continually expand at a constant rate?

This assumes they keep multiplying and colonizing outward. There is no real upper limit - except, eventually, the accelerating expansion rate of the universe that keeps them from reaching further. Because the colonized volume is so large, we don't really assume these colonized volumes form a coordinated empire. It would be more like a loose tangle of city states spread across a vast landscape. They might share common heritage, technology and some amount of culture, but be otherwise independent.

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