Storing the energy from a star

[SpaceMouse]

On the Kardashev scale, its generally agreed that a type 2 civilization would be able to harness the total energy from its star. I don't think I've ever heard of how that might be accomplished though. We have no battery storage method that would be practical at that scale surely, so how might we go about it? Spin up a small moons core?

[HebaruSan]

I've always assumed that it meant your civilization was simply that big. O'Neill cylinders throughout the habitable zone, trillions or quadrillions of individuals or more.

Failing that, one way to "store" it is to slow down the rate of production:

 

[SpaceMouse]

20 minutes ago, HebaruSan said:

I've always assumed that it meant your civilization was simply that big. O'Neill cylinders throughout the habitable zone, trillions or quadrillions of individuals or more.

Failing that, one way to "store" it is to slow down the rate of production:

 

Yeah, I've watched Issac's video's and am familiar with starlifting. It's implied you would only be using what you need but, I don't think you can scale a star that much and, I still think you'd need energy storage on a truly massive scale.

Edited March 8, 2018 by SpaceMouse

[HebaruSan]

11 minutes ago, SpaceMouse said:

It's implied you would only be using what you need but, I don't think you can scale a star that much and, I still think you'd need energy storage on a truly massive scale.

But, storage for what purpose? If the sun is giving off more energy than you need to run your civilization right now, then you don't need any storage capacity, because you can satisfy all of your needs with fresh sunlight. Storage implies alternating periods of overproduction and overconsumption, as on a planetary surface with a day/night cycle.

[kerbiloid]

They can make a small black hole (happily they have a star-scale power for this).

To store the energy they can send light into the hole.

To extract energy they can send some things and split them right above the event horizon.
One half of the thing falls into the hole, another one (due to the conservations laws) gets additional energy. They catch it and get the energy.
If the latter thing is a photon, there is no problem to catch it.

Also they can receive energy by placing some devices near the event horizon where virtual particles-antiparticles  appear.

8 minutes ago, HebaruSan said:

But, storage for what purpose?

Greediness. Why miss a freebie?

Edited March 8, 2018 by kerbiloid

[YNM]

Energy storages are only needed because there's an imbalance between production and consumption. For civilizations that big, I question whether they're needed or not on large scales. For instance, they could simply makes such that the needs are switched over - think of a global electricity network, ie. solar power on Earth, all the demands are at the night side. Now you need to store them down as you have to "take turns" in getting the power. But a live transmission from a sunny America to a starry Australia could mean storage are no longer needed.

Alternatively, such civilization would live in near-constant overproduction; you'll just have to turn on and off your "energy converters".

Obviously, this doesn't get rid of small-scale storages.

Now, controling the energy producer (ie. the star)... Wouldn't that get you further up the scale or something ?

Edited March 8, 2018 by YNM

[Green Baron]

3 hours ago, SpaceMouse said:

 I don't think I've ever heard of how that might be accomplished though.

errr, there is one single more or less civilized planet in the known universe. How relevant is a scale built on hypothetic and arbitrary assumptions and fantasies from the space race age ? Maybe that's why people always think of late industrial age and type contraptions magically put into space to do something with sound and movement. The future belongs to realm of fantasies :-)

Nobody can answer that question, the energy production of a star is by many magnitudes too high to do anything useful with it, except let it radiate away or use a small portion with the good old method of energy conversion through solar panels or photosynthesis.

Edited March 8, 2018 by Green Baron

[p1t1o]

The star *is* storage, a type II civilisation has just learned how to tap the storage effectively.

The highest density storage possible is in the form of matter, and what is a great big collection of matter? A star.

Your star running on empty? You're a type II civ so...build a new one. (Or, I guess you could just travel to another one, if you want to be boring)

[Green Baron]

2 minutes ago, p1t1o said:

The star *is* storage,

That's the point. But it can't be depicted so colourful like huge machines hustling about, doing something useful :-)

[PB666]

The Isaac Arthur video depicts the use of fusion energy and a dyson swarm to create a magnetic field such that electrically charged particles end up at the poles, where somehow passing ships siphon off the gas and store it, according to the logic if you siphon off enough gas, young enough in a stars life, then it becomes a brown dwarf that lives forever, therefore prolonging the life of your civilization.

A couple of flaws in the theory
1. Current fusion power does not create such a power or have a level of efficiency that it might be used in space.
2. the creation of the magnetic field requires ships to be fairly close to the star, an operating environment hostile to any of our known materials.
3. although alpha particles are charged, the solar gases tend to be protonic in nature, the first electron of a proton is rather more easily removed and because they accelerate more quickly, this would cause an older start basically want to go the direction of a white dwarf. Over time the amount of helium, carbon, oxygen would build up in the core.

The author of the video, when interviewed elsewhere appears to have a great deal of skepticism whether type II and III civilizations as star farming would be notable signs of a sentients presence, even in relatively closeby galaxies. No such evidence of dyson swarms have been observed. In particular if you are converting the stars sunlight to energy as close range, your swarm is going to have a huge infrared signature, but not show much in the form of light.

[SpaceMouse]

2 hours ago, PB666 said:

The Isaac Arthur video depicts the use of fusion energy and a dyson swarm to create a magnetic field such that electrically charged particles end up at the poles, where somehow passing ships siphon off the gas and store it, according to the logic if you siphon off enough gas, young enough in a stars life, then it becomes a brown dwarf that lives forever, therefore prolonging the life of your civilization.

A couple of flaws in the theory
1. Current fusion power does not create such a power or have a level of efficiency that it might be used in space.
2. the creation of the magnetic field requires ships to be fairly close to the star, an operating environment hostile to any of our known materials.
3. although alpha particles are charged, the solar gases tend to be protonic in nature, the first electron of a proton is rather more easily removed and because they accelerate more quickly, this would cause an older start basically want to go the direction of a white dwarf. Over time the amount of helium, carbon, oxygen would build up in the core.

The author of the video, when interviewed elsewhere appears to have a great deal of skepticism whether type II and III civilizations as star farming would be notable signs of a sentients presence, even in relatively closeby galaxies. No such evidence of dyson swarms have been observed. In particular if you are converting the stars sunlight to energy as close range, your swarm is going to have a huge infrared signature, but not show much in the form of light.

I have a few issues with the Kardashev scale personally If you've got the tech to make fusion reactors it feels like just building small ones on your planet would be a more practical solution. I used it as its considered the standard. I still think it's fun to speculate about how you might store so much even if you don't really NEED to.

[p1t1o]

11 minutes ago, SpaceMouse said:

I have a few issues with the Kardashev scale personally If you've got the tech to make fusion reactors it feels like just building small ones on your planet would be a more practical solution. I used it as its considered the standard. I still think it's fun to speculate about how you might store so much even if you don't really NEED to.

You need to think bigger. A Kardashev type II civilisation has found a use for the total energy output of their star. It is unlikely they are still limited by the surface area of a planet, usng their dyson sphere to power their electric juicer. Think planetary engineering, ringworlds, taking Jupiter apart as an art project etc.

But the Kardashev scale has always been more of a thought experiment than a practical way of characterising civilisations.

[SpaceMouse]

29 minutes ago, p1t1o said:

You need to think bigger. A Kardashev type II civilisation has found a use for the total energy output of their star. It is unlikely they are still limited by the surface area of a planet, usng their dyson sphere to power their electric juicer. Think planetary engineering, ringworlds, taking Jupiter apart as an art project etc.

But the Kardashev scale has always been more of a thought experiment than a practical way of characterising civilisations.

It's not so much the power usage I have a problem with, I have no doubt a intelligent civilization would use colossal amounts of power. It's more the concept we keep trying to define everything that might happen in the universe in human terms. I have the same issue with our search for life. We're basically looking for things we know and we have no reason to believe another society would develop the same way we did. It's a gross oversimplification.

[p1t1o]

6 minutes ago, SpaceMouse said:

It's a gross oversimplification.

Oh yes, the Kardashev scale certainly is that.

But I disagree about the "human terms" part, if anything the scale is designed specifically to identify things that are nothing like humanity. It hinges on the idea that any civilisation, no matter how strange or alien, needs energy, and classifying them based on the order of magnitude of their use of it. It simplifies things in order not to anthropomorphise them. I think.

[PB666]

1 hour ago, SpaceMouse said:

I have a few issues with the Kardashev scale personally If you've got the tech to make fusion reactors it feels like just building small ones on your planet would be a more practical solution. I used it as its considered the standard. I still think it's fun to speculate about how you might store so much even if you don't really NEED to.

There are a couple of issues here, let me start with the most abstract.
Evolution is really fast (and if need be it can accelerate also), in 500 million years human descendants (500 million years ago, fish did not exist, something like tunicate that had a free swimming stage), if we survive, we be nothing like people today, so that our needs today may not represent our needs tomorrow. More to the point if we started having children in space, overtime humans would evolve to be compatible with life in space (zero gravity tolerance, more tolerant to radiation). Provided an ample supply of nutrients species can adapt to anything, e.g. chernobyl.

So the idea here is that in 300,000 million years the Earth and all similar yellow stars will expand and wipe out all the species living on those planets, so how do species survive . . . . .go interstellar, prevent your star from expanding . . .

The problem here is efficiency. Where you are at, a yellow star, we could think of a yellow star as a nursery, this is where life is more likely to start, the goldilocks zone has a sure point in which life can arise and produce sentiency, where as white blue stars produce to much UV (although species could adapt, the problem is that the light gasses in the atmosphere cannot, they evolve into space), Red stars produce more heat than useful radiation, to be close enough to the star to get photosynthesis basically burns off alot of water. Thus the goldilocks zone is actually a zone where life might exist, if even transiently, but a much much smaller zone where sentients evolve.
   The next issue is preserving your star, but why? there are so many long-lived red stars, why not just move to one of those. Red stars are mostly unstable, but as they age they stabilize and they then burn for 10s of billions of years with very predictable outputs. Moving into orbit around red stars is a solution. But what are the problems. Heat, there is alot more heat than photovoltaic radiation.

e = hf there is more energy to be gained in higher wavelengths and easier to obtain, current modern PVs can be stacked to absorb at three wavelengths, getting efficiency up to 42%, but this is star relative efficiency. If we moved those to a red star, efficiency would drop. The second problem is to make use you have to get so close to the star, you have a heat problem, and panel weights increases . . . . .HUman need to become grossly more efficient at managing heat before we could even make an interstellar ship (the fusion problem) or live around a red star.

So basically extracting hydrogen from a yellow star turns it into a red star, thus by that time you are so good with fusion, you don't care about solar. If you are good with fusion you are good at managing heat and extracting energy, so the heat is not a problem either. But just because you can extract heat does not mean every thing goes cold, it just means you get work out of it (somewhere along the line moving the heat from one system to another), the heat is still there. If we are doing it properly we take infrared radiation and release energy CMBR temperature and red shows up where we are working probably somewhere out in the system where it dark.
You could use the heat to convert say helium back into hydrogen and dueterium, or iron back into lighter elements (we don't know how to do that, particularly, but you could store energy in hydrogen). You could be using the energy you store to create photonic racetracks that use solar and heat conversion to propel craft between the stars (which increasing looks like what interstellar travel will be, slow generational ships carried on rivers of photons). Somewhere (sooner rather than later) however the energy of the star needs to be given up as heat and increase entropy or the system doesn't work.

So the bottom line is that humans descendant species (if we survive) will leave Earth and venture the stars . . . . . .and to do that we need to manage (exploit, manipulate, otherwise exploit physical systems and redirect the minutia of entropy) energy in our solar system better and a dyson swarm is one solution. Another solution is you exploit only enough to leave and find a more stable star(s). Dyson swarms and star farming is something that involves fusion. Three things 1. we have to get it to work 2. it cannot be dumping huge amounts of energy into the craft but power that can be easily transferred where needed 3. And do this without a prohibitive amount of mass. Otherwise all the energy produced will be sunk into pushing the mass around. 

 

18 minutes ago, p1t1o said:

Oh yes, the Kardashev scale certainly is that.

But I disagree about the "human terms" part, if anything the scale is designed specifically to identify things that are nothing like humanity. It hinges on the idea that any civilisation, no matter how strange or alien, needs energy, and classifying them based on the order of magnitude of their use of it. It simplifies things in order not to anthropomorphise them. I think.

Or to put otherwise, to become a Kardashev scale being, significant evolution to that effect has occurred, this may include non-organic sentients.

[kerbiloid]

If a civilisation can manipulate with star-scale masses and energies, it should better squeeze the star into a neutron star or a white gnome and build a much smaller Dyson sphere around it.

Edited March 10, 2018 by kerbiloid