Speculation like this is fun, but I think it's little more than intellectual masturbation until we crack fusion energy. Until we understand the energy economy with such technology, and the most efficient way to leverage it, we're not going to understand the most significant factors that we should be considering. And even then, we'll only be starting to get the slightest clue of how Type II and III civilisations might work.
Type III Societies (Apparently) Do Not Exist
81–90 of 91 posts
Re: Type III Societies (Apparently) Do Not Exist
#82Earlier 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.
Stars use different fuel than reactors. To fuse simple hydrogen, four nuclei have to collide at once. This is so unlikely that it requires a very large mass of fuel to sustain a reaction: at least the size of the Earth, according to one article I saw.
It's entirely possible to burn deuterium in small reactors but there's only about 1/2500 as much deuterium as hydrogen.
(Perhaps some unthinkably advanced civilization could figure out how to get energy from hydrogen fusion in a small reactor, but you did specify "our current understanding of physics.")
Re: Type III Societies (Apparently) Do Not Exist
#83Earlier quoted context omitted.
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.
Stars use different fuel than reactors. To fuse simple hydrogen, four nuclei have to collide at once. This is so unlikely that it requires a very large mass of fuel to sustain a reaction: at least the size of the Earth, according to one article I saw. It's entirely possible to burn deuterium in small reactors but there's only about 1/2500 as much deuterium as hydrogen. (Perhaps some unthinkably advanced civilization…
That's not accurate, stars have several fuel cycles for pure hydrogen. At 1.3 solar masses you sun mostly get: https://en.wikipedia.org/wiki/CNO_cycle
As to size, on galactic scales all our current fusion designs are tiny. Scale it up to even just 20 miles on a side and proton proton fusion is doable. For a type III civilization capable of destroying starts that's also tiny. Remember your suggesting dysons spheres as the 'reasonable' option.
PS: The proton proton chain also produces deuterium as an intermediary. https://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_re...
Re: Type III Societies (Apparently) Do Not Exist
#84If 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…
> In summary, we're looking for ANCIENT Type III civilizations.
Yes. This is because of the low probability that intelligent life develops somewhere else at even close to the same time as it did on Earth.
Our best understanding is that life has existed on Earth for something like 4 billion years, and complex life has existed for about 500 million. However, complex life capable of building spacecraft (or even radios) has only existed for a few hundred thousand (that is being extremely generous, of course), and only developed that technology in the last ~100 years.
If intelligent life has or will evolve somewhere else in the universe, and progresses anything like it did here, then the odds seem overwhelmingly in favour of one of two scenarios:
- It evolved millions of years ago, and if it has not wiped itself out, is virtually god-like by our standards due to its head start on technological development.
- It has not yet evolved, or at best is the equivalent of primates or the proto-humans of several hundred thousand years ago.
Re: Type III Societies (Apparently) Do Not Exist
#85They call economics a "dismal science", but I find such attempts at 'astrophysics' (or whatever this and stuff like the Drake equation are called) even more dismal... Tons of unknown variables filled-in with vigorous hand waving, ad-hoc and unproven assumptions left and right, etc, and some high school math thrown in for good measure...
The "dismal science" thing has nothing to do with scientific standards. It was an expression coined and used by Thomas Carlyle in satirical essay in favor of slavery to refer to political economy because economist's support for emancipation. But I get what you mean.
As for the origin of the quotation yes -- but it has been used to talk about scientific standards in Economy ever since it was coined -- there are even a couple of books with that exact name on the topic.
Re: Type III Societies (Apparently) Do Not Exist
#86Harnessing 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.
Just to play devil's advocate -- density isn't everything either. Plants on Earth play an incredible optimization game. Water is necessary not just for chemical metabolism, but because throwing it away is an essential part of the internal material transport systems of a plant. Evaporation in the leaves creates a relatively lower osmotic pressure in the higher levels of the plant. Between capillary action and the slig…
>>just like evaporation as one end of a pump for plants on Earth is clearly no comparison to any motorized pump for volume
But what if we need/want volumes? The way we can't (or don't want to) use trees/plants for pumping water in time-efficient manner, we may not (want to) use the gravity brute force based stars as energy sources and we may invent more time-efficient fusion reactors.
Re: Type III Societies (Apparently) Do Not Exist
#87Harnessing 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.
Just to play devil's advocate -- density isn't everything either. Plants on Earth play an incredible optimization game. Water is necessary not just for chemical metabolism, but because throwing it away is an essential part of the internal material transport systems of a plant. Evaporation in the leaves creates a relatively lower osmotic pressure in the higher levels of the plant. Between capillary action and the slig…
A Type III civ is probably going to take the long view. The really long view. And in the long run, efficiency is everything.
Stars are just so wasteful; all that energy going into convection currents, and you have to build this big damned sphere to capture all the energy. Better to lift the damned thing and, at the very least, make a dwarf star out of the larger ones. Now you're talking trillions of years of burning (it's still a trash fire, but at least it's manageable).
Re: Type III Societies (Apparently) Do Not Exist
#88Earlier quoted context omitted.
I am a big fan of The Culture . Also, it sounds like you just posited that advanced civilizations would effectively exercise population control, otherwise avoid shortages and avoid the necessity of rapid spatial expansion though technological means.
My belief is that advanced civilizations would naturally end up with what is effectively population control, without any actual active work towards that goal. As birth control becomes easy and prevalent, unwanted pregnancies stop happening. And it seems reasonable to me that, given greatly extended life span / effective immortality, people will naturally choose to wait longer before having children (if they have any…
So this does pretty much amount to population control
From the POV of an outsider or a different species, would any entity care about the difference between "effectively/pretty much" and what you deem to be "actual" population control?
I doubt it.
So basically, you haven't been disagreeing with me, just splitting hairs on what the words "population control" means. I'm using a more generic criteria: Is the population controlled?
Re: Type III Societies (Apparently) Do Not Exist
#89I 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.
This isn't true for all species, it's (in a way) different depending on species. Your statement assumes that evolution is a constant, time-dependent process; it isn't.
For an example, I point to the horseshoe crab. We're separated by x million years of evolution from the horseshoe crab, because at some point there's a common ancestor. Its ancestor evolved to the horseshoe crab, millions of years ago, and then stopped. Meanwhile, our ancestor continued to evolve into us. The horseshoe crab is a prehistoric animal, a "living fossil". It hasn't evolved significantly in millions of years. This is quite different from mice.
Another example is the coelacanth fish; it was thought to be long-extinct as we have prehistoric fossils of it dating to the dinosaur days. Turns out it's still alive. Another less-extreme example is the shark: it's a little different than its prehistoric ancestors, but not much. I'm sure a biologist could point to a bunch of other species that haven't changed significantly since the days of the dinosaurs.
Mammals like mice have indeed been evolving just as long as we have, but many non-mammalian species have not.
Re: Type III Societies (Apparently) Do Not Exist
#90Earlier quoted context omitted.
Well, if you emitted it all in a beam away from the plane of your galaxy, that might make you very stealthy. That would impart thrust on the sphere... which if it wasn't perfectly balanced might cause it to wobble, and then start rotating... ... and now we have a sci-fi reason for quasars. :)
You could direct the waste in two beams perpendicular to the plane of the galaxy, in order to balance net thrust. I question how stealthy that would really make you, though. If someone was bothering to look for stealthy civilizations, they'd just have to scatter some observatories around their region of the galaxy, then watch. Eventually, your structure would occult a star from the POV of one of those observatories,…
Maybe they figured out how to create an artificial wormhole and direct their waste heat into that....