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Type III Societies (Apparently) Do Not Exist

arxiv.org

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Re: Type III Societies (Apparently) Do Not Exist

#71

Post by adrianN »

kabdib wrote: post #55

Harnessing stellar output might not be that interesting. Power density inside stars kind of sucks (about that of a reptile) and stars have bad failure modes. You're probably better off disassembling the suckers and storing their matter in a sensible way, rather than have it sit there, burning. Stars are kind of like trash fires; maybe we should be looking for less energy in a type III civ, not shielding.

If I had super cool tech, I'd use Hawking radiation from small black holes as my means of turning matter into usable energy. Much more compact than a star, and the energy density is also a lot better.

Re: Type III Societies (Apparently) Do Not Exist

#72

Post by gerbal »

pjdorrell wrote: post #58

He estimates f_l, the probability of life arising in a habitable planet, as 0.1. Abiogenesis has never been observed to occur independently of its presumed occurrence when life started on Earth. Given the current state of scientific knowledge on this topic, the only certain lower bound on this number is the probability of molecules in a suitable "organic soup" arranging themselves into a self-contained bacterium. And…

Even if abiogenesis is common, the transition from simple to complex cells is incredibly uncommon. As far as we can tell it only happened on earth once in 4 billion years.

f_l may be 0.1 but f_i is almost certainly multiple orders of magnitude smaller.

Re: Type III Societies (Apparently) Do Not Exist

#73

Post by sgt101 »

xemoka wrote: post #30
sgt101 wrote: post #23

I wonder what ants think of airports? Or what mice believe about tube trains as they scuttle under the platform. We are separated from mice (or at least somewhat similar animals) by approximately 40m years of evolution, I think that the separation to a Galaxy altering level entity would be much more profound, and frankly we wouldn't understand what it was if it came and tickled us.

We are in no way separated by 40m years of evolution. Our common ancestor 'is'. That mouse you see today has been evolving just as long as you have, but with different priorities.

Hello - I said "somewhat similar animals" by which I meant very early primates who were a bit like squirrels and mice. I should have made it a bit clearer!

I did get the date wrong - I should have said 65my.

Here is a link

http://www.smithsonianmag.com/science-nature/five-early-prim...

Re: Type III Societies (Apparently) Do Not Exist

#74

Post by drKarl »

If we expect to see the "brightness of the blackbox caused by the radiation of a Type III Kardashev Civilization", and we inspect galaxies that are maybe millions of light-years away from us, would we not be looking at how did those galaxies look millions of years ago?

That is, maybe there are Type III Kardashev Civilizations and their usage of the energy of their galaxy in fact radiates energy that would be visible to us... except that they've evolved to that point much later that the light we're receiving since it takes millions of years for that light to reach us.

In those millions of years they could very well have reached that technological level, but it will take some more millions of years for that to reach us... by that time mabye that Civilization doesn't exist anymore... Maybe our civilization doesn't exist anymore...

In this case we extract information from the radiation that comes from those galaxies, and the information is too slow to travel such vast distances, since it can't go faster than the speed of light.

In summary, we're looking for ANCIENT Type III civilizations.

Re: Type III Societies (Apparently) Do Not Exist

#75

Post by T-A »

stcredzero wrote: post #57
state_less wrote: post #46

Earlier quoted context omitted.

I think the Fermi paradox has a hidden assumption, that we are intelligent enough to detect aliens. We couldn't detect that the earth revolves around the sun till quite recent in our (genetic beings on earth) evolution. I say give it a few years, we'll figure out that aliens are too alien right now to us. Computationally speaking, our brains are quite limited, though we have recently gained the ability to share ideas…

https://xkcd.com/638/

https://xkcd.com/1377/

Re: Type III Societies (Apparently) Do Not Exist

#76

Post by basicplus2 »

well.. if we don't get off this planet within the next (approx) 4 Billion years.. our species will snuff it as the sun grows to a red giant.

so assuming all life across the universe starts from similar beginnings as us, then this tells us something about what an advanced civilisation needs to be capable of to survive.

Re: Type III Societies (Apparently) Do Not Exist

#77

Post by zamalek »

Semiapies wrote: post #42

This really tells us extremely little about advanced civilizations, beyond that we haven't seen them doing a few variations on a very specific activity—harnessing all the stellar radiation in their galaxy. There are huge number of assumptions based on that idea. A fundamental one is that a civilization in a relativistic universe would grow to densely inhabit a galaxy. Another is that they would need that much energy.…

> Another is that they would need that much energy.

Even if they needed that much energy, the best way to do that [that we know of] is to build a Dyson sphere. With every star shrouded by a Dyson sphere you no longer need to shroud the galaxy.

A more critical assumption is that a type III civilization even cares about masking its presence. If they were even worried about being attacked, the speed of light would mask their progress for a great deal of time and, because of the distances involved, even seeing them once the light reaches you would be a massive accomplishment - most likely you'd have to search for individual stars in another galaxy which are disappearing in unusual ways.

A type II civilization could possibly build a telescope with a large enough aperture but I assume that type II civilizations would be long past their ignorant warring ways.

Re: Type III Societies (Apparently) Do Not Exist

#78

Post by Retric »

zamalek wrote: post #77
Semiapies wrote: post #42

This really tells us extremely little about advanced civilizations, beyond that we haven't seen them doing a few variations on a very specific activity—harnessing all the stellar radiation in their galaxy. There are huge number of assumptions based on that idea. A fundamental one is that a civilization in a relativistic universe would grow to densely inhabit a galaxy. Another is that they would need that much energy.…

> Another is that they would need that much energy. Even if they needed that much energy, the best way to do that [that we know of] is to build a Dyson sphere. With every star shrouded by a Dyson sphere you no longer need to shroud the galaxy. A more critical assumption is that a type III civilization even cares about masking its presence. If they were even worried about being attacked, the speed of light would mask…

Dyson's spheres have low long term fuel efficiency. They are better off destroying the stars and burning their fuel in fusion reactors. At least with our current understanding of physics.

Also, a civilization could have dimantled Andromida Galaxy 2 million years ago and can't tell yet. For more distant objects the gap gets rather wide.

Re: Type III Societies (Apparently) Do Not Exist

#79

Post by zamalek »

Retric wrote: post #78
zamalek wrote: post #77

Earlier quoted context omitted.

> Another is that they would need that much energy. Even if they needed that much energy, the best way to do that [that we know of] is to build a Dyson sphere. With every star shrouded by a Dyson sphere you no longer need to shroud the galaxy. A more critical assumption is that a type III civilization even cares about masking its presence. If they were even worried about being attacked, the speed of light would mask…

Dyson's spheres have low long term fuel efficiency. They are better off destroying the stars and burning their fuel in fusion reactors. At least with our current understanding of physics. Also, a civilization could have dimantled Andromida Galaxy 2 million years ago and can't tell yet. For more distant objects the gap gets rather wide.

Overall I think the main agreement here is that humanity is far too ignorant to even posit how a type III would operate - never mind figure out how to detect them.

Re: Type III Societies (Apparently) Do Not Exist

#80

Post by todd8 »

Semiapies wrote: post #42

This really tells us extremely little about advanced civilizations, beyond that we haven't seen them doing a few variations on a very specific activity—harnessing all the stellar radiation in their galaxy. There are huge number of assumptions based on that idea. A fundamental one is that a civilization in a relativistic universe would grow to densely inhabit a galaxy. Another is that they would need that much energy.…

Oh, that might explain where all the antimatter went. :)
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