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Grabby Aliens (2021)

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Re: Grabby Aliens (2021)

#61

Post by c22 »

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…

I like option 4. Perhaps some of the things we think are black holes are just grabby aliens.

Re: Grabby Aliens (2021)

#62

Post by Veserv »

sevensevennine wrote: post #39
Veserv wrote: post #37

Earlier quoted context omitted.

The hypothesis goes: I want humans to be casually interstellar and expand across the galaxy. I want this to occur in less than N years, N If humans are casually interstellar and expansionist, then we would colonize the galaxy in M years, M Humans are not special, therefore if another alien species existed in the past at current human tech levels, then they would do the same as humans would and colonize the galaxy wit…

I don't follow the last point in your argument. Isn't 4 equivalent to, 'no civilization will invent casual interstellar travel/spread to the stars'? And isn't that hypothesis extremely likely, given what we now know about the costs of _interplanetary_ travel and its relative ease compared to interstellar travel? That's another assumption, that it's _possible_ to colonize a galaxy from a planetary base. We don't even…

You have missed the point. The goal is humanity becoming Star Trek and enclosing every star in a Dyson Sphere; the goal is determining whether 4 is true or false. The question is what is stopping it. The entire point of these thought exercises is setting up proof by contradictions/falsifiable experiments to narrow that down.

Maybe (4 is false) is inevitable now that humanity has reached its current point. Maybe literally every human-like species will become Star Trek and enclose every star in a Dyson Sphere; that would be awesome since it means our goal is now a foregone conclusion. But how would we know? Well, we can do a thought experiment assuming it and extrapolate toward characteristics that we might be able to detect to falsify our hypothesis.

Well if literally every human-like species will enclose every star in the future, then we should not be able to see any stars at some point after one comes into existence. We can still see stars, therefore either it has not happened yet (1), there are no other human-like species (2), or the supposition is false (3). If the supposition is false, then there are risks ahead of us. If the supposition is true, then the risks are behind us, but then (1) or (2) must be true. For (1) to be true, we must either be early or it takes a long time. For (2) to be true, we must either be early or rare. If we can rule out (1) and (2), then we must conclude (3) which means we can be confident that there must be a risk ahead of us preventing us from reaching our goal that we as a species need to be wary of even if we do not know what it is specifically. We just know it has to exist otherwise we would see no stars.

If (1) or (2) is true, then (3) no longer needs to be true. It might still be the case that the goal is impossible, but at least we have a chance. The point of this analysis is trying to theorize where we need to look that gives humanity the most information about if and how to become Star Trek. It is not about coming up with the "correct" answer; we do not have enough information for that. We are trying to create theories that take facts that we can find (or can in theory find) as inputs and generate predictions that can be tested and falsified.

Re: Grabby Aliens (2021)

#63

Post by cryptonector »

Animats wrote: post #60

Actual article: [1] "We estimate that loud alien civilizations now control 40%–50% of universe volume, each will later control ∼ 10^5 to 3 × 10^7 galaxies, and we could meet them in ∼200 Myr–2 Gyr." Those numbers seem inconsistent. "Ours is a model of grabby aliens, who by definition (a) expand the volumes they control at a common speed, (b) clearly change the look of their volumes (relative to uncontrolled volumes),…

The speed of light is a tremendous limitation. W/o FTL there's no such thing as "loud alien civilizations" that can "control 40%-50% of [the] universe['s] volume".

Re: Grabby Aliens (2021)

#64

Post by ccheney »

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.

Your point on missing IR halos is valid, but don't overlook anomalies like Tabby's Star (KIC 8462852) [0]. Its odd dimming led to theories about alien megastructures like Dyson Spheres, though dust or comets are possible explanations. Still, Tabby's Star highlights the difficulty in excluding advanced alien activities with our current tech. [1]

[0] https://en.wikipedia.org/wiki/Tabby%27s_Star

[1] https://youtu.be/mZve2Oy3cFg?t=82

Re: Grabby Aliens (2021)

#65

Post by XorNot »

cryptonector wrote: post #63
Animats wrote: post #60

Actual article: [1] "We estimate that loud alien civilizations now control 40%–50% of universe volume, each will later control ∼ 10^5 to 3 × 10^7 galaxies, and we could meet them in ∼200 Myr–2 Gyr." Those numbers seem inconsistent. "Ours is a model of grabby aliens, who by definition (a) expand the volumes they control at a common speed, (b) clearly change the look of their volumes (relative to uncontrolled volumes),…

The speed of light is a tremendous limitation. W/o FTL there's no such thing as "loud alien civilizations" that can "control 40%-50% of [the] universe['s] volume".

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 little chance of victory because of you attacked a place you took along everything needed for overwhelming victory.

Re: Grabby Aliens (2021)

#66

Post by cwillu »

cryptonector wrote: post #63
Animats wrote: post #60

Actual article: [1] "We estimate that loud alien civilizations now control 40%–50% of universe volume, each will later control ∼ 10^5 to 3 × 10^7 galaxies, and we could meet them in ∼200 Myr–2 Gyr." Those numbers seem inconsistent. "Ours is a model of grabby aliens, who by definition (a) expand the volumes they control at a common speed, (b) clearly change the look of their volumes (relative to uncontrolled volumes),…

The speed of light is a tremendous limitation. W/o FTL there's no such thing as "loud alien civilizations" that can "control 40%-50% of [the] universe['s] volume".

As stated in the paper: “The second of our three model parameters is the (assumed universal) speed at which grabby civilizations expand. Our model predicts that on average at grabby origin dates, a third to a half of the universe is within grabby-controlled volumes. So if the grabby expansion speed were low, many such volumes should appear quite large and noticeable in our sky. However, as noted by (Olson ’15; Olsen ’17) and discussed in Section 13, if their expansion speed were within ∼25% of lightspeed, a selection effect implies that we are less likely to see than to not see such volumes. Thus if we could have seen them, they would likely be here now instead of us. As we do not now see such volumes, we conclude that grabby aliens, if they exist, expand very fast.”

Re: Grabby Aliens (2021)

#67

Post by cwillu »

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…

Alas, there's a fifth possibility:

5. Controlled transportation between the stars, sufficient for colonization, is sufficiently impractical that there are no grabby aliens within our light-cone.

Re: Grabby Aliens (2021)

#68

Post by kiba »

ionwake wrote: post #36
kiba wrote: post #26

Earlier quoted context omitted.

We wouldn't know if we're in a simulation unless the diety/programmer wanted us to know that.

Not really I disagree. With software that encourages emergent behaviour we are unaware of the abilities the entities take on. So in theory I think we could.

They can just simply pause, delete, reverse, or make us outright ignore anything. They are literal god and hold ultimate power over us, unless they are willing to deliberately let things happen.

The better question is if it even matter.

Re: Grabby Aliens (2021)

#69

Post by kiba »

saghm wrote: post #55
kiba wrote: post #26

Earlier quoted context omitted.

We wouldn't know if we're in a simulation unless the diety/programmer wanted us to know that.

How would you know? Based on what we know of simulations in this reality, which has rules designed by whoever created it? If you're programming a simulated universe and don't want its inhabitants to know, it seems like a pretty obvious mechanism to try to enforce that would be to make the rules so that it seemed like "leaking" information into a simulation was impossible, even if the rules of their "outer" reality ma…

There's no test that can make us convince ourselves that it's a simulation or not. The real question is if it even matters. We are just as real if we're not a simulation, or are a simulation.

Re: Grabby Aliens (2021)

#70

Post by zarzavat »

actionfromafar wrote: post #6
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.

Barely spacefaring. We are like fish on the shore who can survive in the mud long enough for the tide to come back to rescue us, if that.

That’s just because our neighbourhood is so boring in comparison to Earth.

Imagine that by some chance Mars was another Earth with a breathable atmosphere. NASA would have been given a trillion dollar budget and we would have been there in the 80s. Instead it’s a dead red rock so NASA gets a small budget and the US spends its money on blowing people up instead.

We have the technology to be a spacefaring civilisation but we won’t care until Earth becomes a worse place to be than the rest of the solar system, which is probably never given how bad the other bodies in the solar system are. Most likely we develop Von Neumann probes before we ever get bored of Earth.

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