Smokes some weed…Later…

After the sun becomes a red giant there will be a period of some stability until the suns planetary nebula stage. The term “planetary nebula” is a misnomer because they are unrelated to planets or exoplanets. Wikipedia.

A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

After the sun becomes a red giant, it will later pass through a planetary nebula stage, and after that the sun will settle down to a white dwarf, and after that becomes a black dwarf.

Question 1 How much energy from the nebula will the ionized gas put out?

Question 2 How long will this period be?

Question 3 To escape the nebula using an artificial planet built from using Metal asteroids like 16 psyche which or the outer planets would be best to hide the artificial planet behind, Saturn or Neptune, could this be sufficient to escape the nebula or will we need to build a shield for this purpose?

Tau.Neutrino said:

Smokes some weed…Later…

After the sun becomes a red giant there will be a period of some stability until the suns planetary nebula stage. The term “planetary nebula” is a misnomer because they are unrelated to planets or exoplanets. Wikipedia.

A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

After the sun becomes a red giant, it will later pass through a planetary nebula stage, and after that the sun will settle down to a white dwarf, and after that becomes a black dwarf.

Question 1 How much energy from the nebula will the ionized gas put out?

Question 2 How long will this period be?

Question 3 To escape the nebula using an artificial planet built from using Metal asteroids like 16 psyche which or the outer planets would be best to hide the artificial planet behind, Saturn or Neptune, could this be sufficient to escape the nebula or will we need to build a shield for this purpose?

More thoughts

We need to escape the suns red giant stage first then the suns planetary nebula stage.

The suns planetary nebula stage could involve multiple emissions.

Will using an outer gas planet to hide behind be sufficient?

Will an external shield be required over the artificial planet?

If an external shield is required could the artificial planet have a shield built onto it?

Will both types of protection be required?

Tau.Neutrino said:

Tau.Neutrino said:

Smokes some weed…Later…

After the sun becomes a red giant there will be a period of some stability until the suns planetary nebula stage. The term “planetary nebula” is a misnomer because they are unrelated to planets or exoplanets. Wikipedia.

A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

After the sun becomes a red giant, it will later pass through a planetary nebula stage, and after that the sun will settle down to a white dwarf, and after that becomes a black dwarf.

Question 1 How much energy from the nebula will the ionized gas put out?

Question 2 How long will this period be?

Question 3 To escape the nebula using an artificial planet built from using Metal asteroids like 16 psyche which or the outer planets would be best to hide the artificial planet behind, Saturn or Neptune, could this be sufficient to escape the nebula or will we need to build a shield for this purpose?

More thoughts

We need to escape the suns red giant stage first then the suns planetary nebula stage.

The suns planetary nebula stage could involve multiple emissions.

Will using an outer gas planet to hide behind be sufficient?

Will an external shield be required over the artificial planet?

If an external shield is required could the artificial planet have a shield built onto it?

Will both types of protection be required?

If we survive the next thousand years we’ll still have another 5 billion years to work out what to do when the Sun goes red giant. Plenty of time to colonise the galaxy if we lack the tech to survive in the solar system.

Question 2a How long will the suns planetary nebula period be?

Question 2b Will there be multiple emissions or just one?

Question 2c If it involves multiple emissions, will they be similar or vary, what will their peaks be?

Question 4 Where will be the best place in space to start building them?

Question 5 How big could an artificial planet be?

Question 6 How many artificial planets could be built/ will be needed?

Question 7 What sort of engine requirements be needed ion, nuclear, other?

Question 5 How fast can they be in space?

Question 6 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Tau.Neutrino said:

Question 4 Where will be the best place in space to start building them?

Question 5 How big could an artificial planet be?

Question 6 How many artificial planets could be built/ will be needed?

Question 7 What sort of engine requirements be needed ion, nuclear, other?

Question 5 How fast can they be in space?

Question 6 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Correction

Question 8 How fast can they be in space?

Question 9 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Tau.Neutrino said:

Tau.Neutrino said:

Question 4 Where will be the best place in space to start building them?

Question 5 How big could an artificial planet be?

Question 6 How many artificial planets could be built/ will be needed?

Question 7 What sort of engine requirements be needed ion, nuclear, other?

Question 5 How fast can they be in space?

Question 6 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Correction

Question 8 How fast can they be in space?

Question 9 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Question 10 When do we need to start building them?

Question 11 Because we will need to know how long it will take to build one?

Question 12 What sort of engines to design and fit to them, and how big will they need to be etc

Tau.Neutrino said:

After the sun becomes a red giant there will be a period of some stability until the suns planetary nebula stage. The term “planetary nebula” is a misnomer because they are unrelated to planets or exoplanets. Wikipedia.

A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

After the sun becomes a red giant, it will later pass through a planetary nebula stage, and after that the sun will settle down to a white dwarf, and after that becomes a black dwarf.

Question 1 How much energy from the nebula will the ionized gas put out?

Question 2 How long will this period be?

Question 3 To escape the nebula using an artificial planet built from using Metal asteroids like 16 psyche which or the outer planets would be best to hide the artificial planet behind, Saturn or Neptune, could this be sufficient to escape the nebula or will we need to build a shield for this purpose?

Question 4 Where will be the best place in space to start building them?

Question 5 How big could an artificial planet be?

Question 6 How many artificial planets could be built/ will be needed?

Question 7 What sort of engine requirements be needed ion, nuclear, other?

Question 8 How fast can they be in space?

Question 9 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Question 10 When do we need to start building them?

Question 11 Because we will need to know how long it will take to build one?

Question 12 What sort of engines to design and fit to them, and how big will they need to be etc

Whoa.

I normally pride myself on answering questions like these before I’m asked, but you’ve leapfrogged my thought processes here.

I had only got to the stage of asking myself which planet or moon of the solar system would be a suitably pleasant locale during the red giant stage. And I hadn’t even answered that one. We can rule out Mars for starters – too close in. That leaves large asteroids such as Ceres, the moons of Jupiter or the moons of Saturn. Which one(s) to be determined by calculation.

I hadn’t even thought of a mobile artificial planet – apart from making one from a comet to leave the solar system entirely.

And I hadn’t even thought of the planetary nebula phase or, even worse because it lasts longer, the asymptotic giant branch that follows the red giant stage.

Something perhaps relevant, I’ve calculated already that Earth’s entire biosphere can be squeezed (Noah’s ark style) into 1 gram of organic matter.

Time to break out the slide rules and log tables.

Let’s see if there are any of these questions that I can answer straight away.

> Question 2 How long will this period be?

10,000 years as a planetary nebula.
100,000 years as an asymptotic giant branch star
These times are really short compared to the billions of years we have to wait for it to to start happening.

> Question 3 To escape the nebula using an artificial planet built from using Metal asteroids like 16 psyche which or the outer planets would be best to hide the artificial planet behind, Saturn or Neptune, could this be sufficient to escape the nebula or will we need to build a shield for this purpose?

My immediate thought is to to escape the the radiation form the planetary nebula by building underground or underwater, rather than hiding behind Jupiter, Saturn or Neptune. If hiding behind Jupiter, Saturn or Neptune would have to be at the L2 Lagrangian point, wouldn’t it.

> Question 7 What sort of engine requirements be needed ion, nuclear, other?

Nuclear, definitely. An ion engine powered by nuclear power, a good idea.

Question 13 How to create a long term company that can operate over billions of years and carry out each stage?

Question 14 How many fusion reactors will be required?

Question 15 How many nuclear reactors will be required for the ion engines?

Question 16 How many nuclear engines will be required?

Question 17 How many maintenance robots will be required?

Question 18 How to create a long term internet for each artificial planet and to connect each one?

Question 19 How to store all the worlds information and keep adding to it?

Question 20 How to structure long term telemetry for the artificial planets?

I’ll try and think of some more :)

Tau.Neutrino said:

Question 13 How to create a long term company that can operate over billions of years and carry out each stage?

Question 14 How many fusion reactors will be required?

Question 15 How many nuclear reactors will be required for the ion engines?

Question 16 How many nuclear engines will be required?

Question 17 How many maintenance robots will be required?

Question 18 How to create a long term internet for each artificial planet and to connect each one?

Question 19 How to store all the worlds information and keep adding to it?

Question 20 How to structure long term telemetry for the artificial planets?

I’ll try and think of some more :)

Question 21 Create Long term mapping into the future.

Question 22 Create long term asteroid and comet collision warning systems.

https://iopscience.iop.org/article/10.1088/0004-637X/756/2/132/pdf

“When the Sun ascends the red giant branch (RGB), its luminosity will increase and all the planets will receive much greater irradiation than they do now. Jupiter, in particular, might end up a hot Jupiter. Massive planets around post-main-sequence stars could accrete a non-negligible amount of material from the enhanced stellar winds.”

The Sun will have two bursts of mass output (planetary nebula). The first at 11.94 GYr from now. The second at 12.095 GYr.

In the first the Sun’s radius reaches very close to 1 AU and the mass loss from the Sun is sufficient to push Jupiter’s orbit out from 5.1 AU to 7 AU.

After the first, the Sun’s radius shrinks right back to 0.06 AU for 145 million years.

In it’s death phase, the Sun’s radius expands to 0.72 AU and the mass loss from the Sun is sufficient to push Jupiter’s orbit out to about 9 AU.
To summarise, the Sun’s radius is:
11.5 GYr – 0.012 AU
11.6 GYr – 0.013 AU
11.7 GYr – 0.019 AU
11.8 GYr – 0.03 AU
11.9 GYr – 0.05 AU
11.92 GYr – 0.09 AU
11.94 GYr – 1 AU
11.95 GYr – 0.06 AU
12.09 GYr – 0.06 AU
12.095 GYr – 0.72 AU

(to be continued)

mollwollfumble said:

https://iopscience.iop.org/article/10.1088/0004-637X/756/2/132/pdf

“When the Sun ascends the red giant branch (RGB), its luminosity will increase and all the planets will receive much greater irradiation than they do now. Jupiter, in particular, might end up a hot Jupiter. Massive planets around post-main-sequence stars could accrete a non-negligible amount of material from the enhanced stellar winds.”

The Sun will have two bursts of mass output (planetary nebula). The first at 11.94 GYr from now. The second at 12.095 GYr.

In the first the Sun’s radius reaches very close to 1 AU and the mass loss from the Sun is sufficient to push Jupiter’s orbit out from 5.1 AU to 7 AU.

After the first, the Sun’s radius shrinks right back to 0.06 AU for 145 million years.

In it’s death phase, the Sun’s radius expands to 0.72 AU and the mass loss from the Sun is sufficient to push Jupiter’s orbit out to about 9 AU.
To summarise, the Sun’s radius is:
11.5 GYr – 0.012 AU
11.6 GYr – 0.013 AU
11.7 GYr – 0.019 AU
11.8 GYr – 0.03 AU
11.9 GYr – 0.05 AU
11.92 GYr – 0.09 AU
11.94 GYr – 1 AU
11.95 GYr – 0.06 AU
12.09 GYr – 0.06 AU
12.095 GYr – 0.72 AU

(to be continued)

Gonna need some good slip, slop, slap for that.

I will get around to the original questions – how dangerous is a planetary nebula?
and how easily can you build and move an artificial planet?

I swear.

Tau.Neutrino said:

Question 4 Where will be the best place in space to start building them?

Question 5 How big could an artificial planet be?

Question 6 How many artificial planets could be built/ will be needed?

Question 7 What sort of engine requirements be needed ion, nuclear, other?

Question 8 How fast can they be in space?

Question 9 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

Question 10 When do we need to start building them?

Question 11 Because we will need to know how long it will take to build one?

Question 12 What sort of engines to design and fit to them, and how big will they need to be etc

Question 13 How to create a long term company that can operate over billions of years and carry out each stage?

Question 14 How many fusion reactors will be required?

Question 15 How many nuclear reactors will be required for the ion engines?

Question 16 How many nuclear engines will be required?

Question 17 How many maintenance robots will be required?

Question 18 How to create a long term internet for each artificial planet and to connect each one?

Question 19 How to store all the worlds information and keep adding to it?

Question 20 How to structure long term telemetry for the artificial planets?

Question 21 Create Long term mapping into the future.

Question 22 Create long term asteroid and comet collision warning systems.

OK, let’s start with the power source for these artificial planets.

I’m going to limit the power source to all of the deuterium in the Earth’s oceans, used at 100% efficiency. This could be either an underestimate (much less than the power available from the more readily available hydrogen) or an overestimate (no guarantee that we can use all the worlds oceans of 100% efficiency) so let it stand.

I get 2*10^13 tonnes of deuterium as the power source.
Which gives E = 2*10^28 Joules of energy.

Now look at the Delta V. There’s no point in leaving from Mars because there’s not enough fuel on Mars. Fuel further out would be available, but there are problems with getting it back to where it can be used.

Delta V for Earth to Jupiter capture is 16 km/s
Delta V for Earth to Saturn capture is 17.1 km/s, not too different.
Delta V for out of the Solar System is 18.2 km/s.

Maximum total mass for all artificial planets combined (including mass of fuel) is then (give or take a factor of 2).
m = 2*E/V^2 =2*2*10^28 /(17*10^3)^2 = 2.3*10^21 kg = 2*10^18 tonnes
Is much greater than the 2*10^13 tonnes of fuel. Good.

If this was a single artificial planet made of solid rock, how big would it be?
It would be a sphere of diameter 1000 km. :-)

Big enough for you?
I doesn’t have to be solid of course, or made of rock. So it could be bigger. It could even be made of water.

So deuterium fusion will do it. Get us to Jupiter orbit, Saturn orbit or out of the Solar System.

> Question 4 Where will be the best place in space to start building them?

Near Earth orbit is easiest, but it could be built in up to three different places – Near Earth orbit for fuel, near Moon orbit for bulk, or near Mars orbit if the Moon has got too hot. With extra fittings from the asteroid belt.

> Question 5 How big could an artificial planet be?

Up to 1000 km diameter if solid rock. Or bigger if hollow.

That’s the size of Ceres. Or we could even use Ceres as is.

> Question 6 How many artificial planets could be built/ will be needed?

Only one needed, but it wouldn’t hurt to have a fleet of much smaller ones as a well. For such purposes as fuel transport.

> Question 7 What sort of engine requirements be needed ion, nuclear, other?

I wouldn’t go for anything other than nuclear fusion. But as for which nuclear fusion, there are options such as D + D, D + T, H to He, Li to He etc. Ion drives can be made powered by nuclear fusion. Ion drives have the advantage of being gentle on living things. For a spacecraft this massive a straightforward pulsed combustion rocket would cut down the driving time. Remember that a car engine is just a pulsed combustion engine.

> Question 8 How fast can they be in space?

Fast enough. The above design is for 18.2 km/s, there’s no real need to go faster.

> Question 9 If hiding behind a shield, moon or gas planet in not enough will moving the artificial planet into deep space beyond the solar system be enough?

If living underground during the worst troubles, certainly. If living on the surface then I’d need to go back to questions 1, 2 and 3.

> Question 10 When do we need to start building them?

I’d start before the reverse cycle air conditioner keeping the Earth cool becomes insufficient. ie. before the exodus to the Moon and Mars. I haven’t calculated when that will be yet.

> Question 11 Because we will need to know how long it will take to build one?

Yah. I’ve got a comment here that you won’t like.

It would help a lot if we start the building after almost all of the Earth’s atmosphere has been artificially removed. One way to do that would be to fly a kite, and use the energy of the Earth’s rotation to fling Earth’s atmosphere off into space where it can be captured for recycling. The Earth slows to match, but not be enough to be a problem.

Once the atmosphere is removed, there are at least three ways to send supplies up into space – rail gun, elevator, and nuclear powered rocket.

To transport 2*10^18 tonnes of solid matter into space. Hmm. 500*10^6 tonnes per year is easily achievable. But that makes 4 billion years. We’d need to speed that up.

> Question 12 What sort of engines to design and fit to them, and how big will they need to be etc

We could go with lots of small engines eg. a million engines each putting out 200 megatons a day of fusion power would do. In other words each engine would be 20 trillion watts. I haven’t figured out how to make an engine capable of putting out more than 20 trillion watts continuously over many years.

That covers most of the later questions.

Internet, communications, business plan, collision warning and avoidance are easy questions to solve.

Maintenance is not such as easy question to answer.

I still haven’t answered your Question 1.

Another question I haven’t answered is this. How dense an atmosphere could such an artificial planet maintain on its surface? As dense as Titan’s?

(Don’t forget to read my previous post on this topic, which answers most questions).

Looking further into the Sun’s evolution.

http://adsabs.harvard.edu/pdf/1993ApJ…418..457S

5200 solar luminosities – Yowch, yes, strong sunscreen is needed.
Venus escapes being engulfed – that’s interesting.
400,000 years on the thermally pulsing asymptotic giant branch.

The following is the Sun’s evolution, B is where we are and the solid line is where we’re going. After the first gentle rise through G, and settling back to red giant at J, things get rather messy for survival. Four periods of mass loss from the Sun.

The following shows the initial cooling to white dwarf (star symbol at left). Surviving the heating of the Sun is one thing. Surviving the subsequent cooling is quite another. The most interesting thing here for me is that the Sun’s luminosity in early white dwarf stage is still 100 times as large as it is right now, I was not expecting that. Does this article say how long it takes the Sun to get from a Planetary nebula to a full white dwarf? No, it doesn’t.

In general terms, I had been thinking that we could survive the planetary nebula stage by giving the whole Earth’s biosphere, compressed into a mass of 1 gram of organic matter, a frozen ride into the Oort cloud and back on a long period comet. To avoid the planetary nebula stage.

But we also need to protect all the food-stock for this life so it doesn’t starve when it gets back. And save as much of the water and air as possible. That needs CN’s artificial movable planet strategy. And the movable planet needs a lot of power to get continually closer to the Sun as the white dwarf cools.

There is enough additional description in this article to calculate a lower limit on how powerful the planetary nebula will be. But perhaps I can find a better article.

https://iopscience.iop.org/article/10.1086/133342/pdf

The Expected Morphology of the Solar System Planetary Nebula

Jupiter is likely to deposit a substantial fraction of its orbital angular momentum, in spinning-uptheSun,whenthelatterisontheupperAGB.ThisamountofangularmomentumislikelytocausesomesmalldegreeofaxisymmetricmasslossfromtheSun.Inthiscase,theSunwillformanellipticalplanetarynebula.

https://iopscience.iop.org/article/10.1086/516746/pdf

Can Planets Survive Stellar Evolution?
(not much use)

https://watermark.silverchair.com/mnras0386-0155.pdf

Distant future of the Sun and Earth revisited

the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode,for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. As a result of this, we find that planet Earth will not be able to escape engulfment, despite the positive effect of solar mass loss.

(I’m still not finding what I want) Aha, the next one looks better.

https://arxiv.org/pdf/0811.4052.pdf

The search for a strategy for mankind to survive the solar Red Giant catastrophe.

Short term: “we propose to construct some kind of parasol to shadow Earth.”
Long term: “we have to shift Earth into the Kuiper Belt (50 AU) by means of the swing-by technique whereby the overwhelming part of the gravitational energy needed will be transferred from the orbit of Jupiter and Saturn. During this journey of about 10 megayears.”

Yuk yuk yuk. Neutrino’s plan is much better. There is no way that enough mass can be made to swing by Earth to change its orbit significantly.

“Historically one of the first chains of reasoning was to build a giant space ship for a limited number of survivors, called interstellar colonists, to escape our Solar System. For example Dyson (Dyson, 1968) proposed an ‘Ablation Space Ship’ for a payload of 10 000 tons with a mission velocity of 10 000 km/s. He showed that hydrogen bomb detonations (about 300 000 bombs) could take over chemical propulsion as an energy source for long-range space travel. The bombs would explode behind a huge hollow copper hemisphere covered with some ablating substance protecting the underlying structure and a small layer of the ablating material would be vaporized by each burst-thus increasing the momentum transfer.”

“Korycansky (Korycansky, 2001) proposed the lift up Earth’s orbit (1 AU) to the orbital radius of Mars (~1.52 AU) or something beyond by using gravitational assists to transfer orbital energy from Jupiter (and perhaps Saturn) to Earth using repeatedly highly elliptical orbit (~300 AU ) asteroids from the Kuiper Belt by ‘swing-by’ manoeuvres. An object with a mass of 10^22 g (diameter 100-150 km) every 6,000 years (on average) is guided in such manner that it passes close to the leading limb of Earth, i.e. at the trailing side of its orbital path (distance ~10,000 km). It could do the above job within about 1 Gy if the resulting out-bound trajectory crosses afterwards the orbit of Jupiter to pick up energy that was lost to Earth.”

Not good enough. The energy required to manoeuvre 150,000 Kuyper belt objects into Earth-crossing orbit is enormous. The total mass to be moved here is 1.5*10^27 g. There simply isn’t enough available energy available to do it. By comparison, the Earth’s mass is 6*10^27 g. I did a calculation of this sort that I called “solar system pinball” many years ago. One other overwhelming problem is that such bodies, in order to pick up any significant orbital momentum from Jupiter, would have to have a perijove so close to Jupiter that it would actually crash into Jupiter.

There’s got to be a better article somewhere than any of these.

Perhaps there’s something in the book “Our Cosmic Future: Humanity’s Fate in the Universe” by Nikos Prantzos (translated out of French).
Contents: 1. Near futures; 2. Route to the stars; 3. Star makers; 4. Ultimate futures

Let’s turn Neutrino’s questions on their head and condense them all into:

What is the optimum strategy for maximising the ecosystem size around the Sun as a cooling white dwarf after the planetary nebula phase?

Here is one possible strategy.

Ground rules:
I’ve shown that no object (or sum of objects) much heavier than Ceres can be considered movable.
I’ve shown that Earth’s entire collection of species in suspended animation need weigh no more than 1 gram.

Strategy:
Hollow out Ceres for use in carrying an underground ecosystem. The hollowing out process doubles the diameter.
Plunder the Moon to make a ceramic spacecraft capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Ceres.
Strip off most of the Earth’s atmosphere and place on board this moonmade spacecraft.
Export the Earth’s biosphere to this moonmade spacecraft.
Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonmade spacecraft.
Transport to and install in Ceres underground.
Collect ice and hydrocarbons from the moons of Jupiter and Saturn, transport to Ceres using the moonmade spacecraft.
As things get really hot start collecting hydrogen form the solar wind.
During the worst part, consider a suspended animation trip, Noah’s ark style, to the Oort cloud and back.
After the planetary nebula, use fusion power to bring the Ceres ecosystem nearer the white dwarf as it cools.

mollwollfumble said:

Let’s turn Neutrino’s questions on their head and condense them all into:

What is the optimum strategy for maximising the ecosystem size around the Sun as a cooling white dwarf after the planetary nebula phase?

Here is one possible strategy.

Ground rules:
I’ve shown that no object (or sum of objects) much heavier than Ceres can be considered movable.
I’ve shown that Earth’s entire collection of species in suspended animation need weigh no more than 1 gram.

Strategy:
Hollow out Ceres for use in carrying an underground ecosystem. The hollowing out process doubles the diameter.
Plunder the Moon to make a ceramic spacecraft capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Ceres.
Strip off most of the Earth’s atmosphere and place on board this moonmade spacecraft.
Export the Earth’s biosphere to this moonmade spacecraft.
Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonmade spacecraft.
Transport to and install in Ceres underground.
Collect ice and hydrocarbons from the moons of Jupiter and Saturn, transport to Ceres using the moonmade spacecraft.
As things get really hot start collecting hydrogen form the solar wind.
During the worst part, consider a suspended animation trip, Noah’s ark style, to the Oort cloud and back.
After the planetary nebula, use fusion power to bring the Ceres ecosystem nearer the white dwarf as it cools.

I’m adding a timescale to the heating up of the Sun, and there are problems, long before we need to hollow out Ceres

The first problem is the problem of ‘Earth too hot, Mars too cold’

There is a slow rise in solar luminosity over the next 6.6 billion years. The problem is that Earth is too hot and Mars is too cold for a lot of that time. By the end of the slow heating, the surface temperature of Earth is about 90 degrees C, too hot. But Mars is still only -10 degrees censius on average.

A later problem is that Ceres is both too far and too near the Sun. It’s nicely pleasant on the surface for 60 million years, which is actually a really long time in the end times of the Sun, making it worth the effort. For most of the time it’s too cold. For 60 million years it’s way too hot on the surface of Ceres. For solar peak luminosity (Planetary nebula stage), Pluto and Triton are starting to look tempting. Or (as Neutrino suggests), hiding behind Jupiter. This deadliest of times only lasts 1 million years, which unfortunately is too short for Pluto or Triton to equilibrate and too short to move Ceres behind Jupiter.

mollwollfumble said:

mollwollfumble said:

Let’s turn Neutrino’s questions on their head and condense them all into:

What is the optimum strategy for maximising the ecosystem size around the Sun as a cooling white dwarf after the planetary nebula phase?

Here is one possible strategy.

Ground rules:
I’ve shown that no object (or sum of objects) much heavier than Ceres can be considered movable.
I’ve shown that Earth’s entire collection of species in suspended animation need weigh no more than 1 gram.

Strategy:
Hollow out Ceres for use in carrying an underground ecosystem. The hollowing out process doubles the diameter.
Plunder the Moon to make a ceramic spacecraft capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Ceres.
Strip off most of the Earth’s atmosphere and place on board this moonmade spacecraft.
Export the Earth’s biosphere to this moonmade spacecraft.
Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonmade spacecraft.
Transport to and install in Ceres underground.
Collect ice and hydrocarbons from the moons of Jupiter and Saturn, transport to Ceres using the moonmade spacecraft.
As things get really hot start collecting hydrogen form the solar wind.
During the worst part, consider a suspended animation trip, Noah’s ark style, to the Oort cloud and back.
After the planetary nebula, use fusion power to bring the Ceres ecosystem nearer the white dwarf as it cools.

I’m adding a timescale to the heating up of the Sun, and there are problems, long before we need to hollow out Ceres

The first problem is the problem of ‘Earth too hot, Mars too cold’

There is a slow rise in solar luminosity over the next 6.6 billion years. The problem is that Earth is too hot and Mars is too cold for a lot of that time. By the end of the slow heating, the surface temperature of Earth is about 90 degrees C, too hot. But Mars is still only -10 degrees censius on average.

A later problem is that Ceres is both too far and too near the Sun. It’s nicely pleasant on the surface for 60 million years, which is actually a really long time in the end times of the Sun, making it worth the effort. For most of the time it’s too cold. For 60 million years it’s way too hot on the surface of Ceres. For solar peak luminosity (Planetary nebula stage), Pluto and Triton are starting to look tempting. Or (as Neutrino suggests), hiding behind Jupiter. This deadliest of times only lasts 1 million years, which unfortunately is too short for Pluto or Triton to equilibrate and too short to move Ceres behind Jupiter.

The solution to the problem of ‘Earth too hot, Mars too cold’ is to either cool the Earth, heat Mars, live on the night side of the Moon, or live on a spaceship between Earth and Mars. Or all of the above.

Strategies for cooling the Earth include:

• Installing a parasol in space
• Changing the atmosphere
• Installing a reverse cycle air conditioner
• Stopping the Earth’s rotation and living on the night side

An alternative strategy to the use of Ceres as a spaceship is as follows:

• Plunder the Moon to make a ceramic moonship capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Jupiter
• Strip off most of the Earth’s atmosphere and place on board this moonship
• Export the Earth’s biosphere to this moonship
• Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonship
• Over the next 6.6 billion years, slowly increase the moonship’s orbit out half way to Mars
• Transport to the moons of Jupiter over the next 1 billion years
• Terraform the moons of Jupiter and collect nuclear fuel from them.
• Hollow out moons Amalthea and Himalia and move to Jupiter’s L2 lagrange point (using Jupiter to block the sunlight)
• Hide on Amalthea, Himalia, the moonship and in orbit around Triton and Pluto during the hottest phases of the Sun
• Seed ecosystems on Triton and Pluto
• After the planetary nebula, use fusion power to bring Amalthea, Himalia, and the moonship near the white dwarf as it cools.

mollwollfumble said:

mollwollfumble said:

mollwollfumble said:

Let’s turn Neutrino’s questions on their head and condense them all into:

What is the optimum strategy for maximising the ecosystem size around the Sun as a cooling white dwarf after the planetary nebula phase?

Here is one possible strategy.

Ground rules:
I’ve shown that no object (or sum of objects) much heavier than Ceres can be considered movable.
I’ve shown that Earth’s entire collection of species in suspended animation need weigh no more than 1 gram.

Strategy:
Hollow out Ceres for use in carrying an underground ecosystem. The hollowing out process doubles the diameter.
Plunder the Moon to make a ceramic spacecraft capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Ceres.
Strip off most of the Earth’s atmosphere and place on board this moonmade spacecraft.
Export the Earth’s biosphere to this moonmade spacecraft.
Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonmade spacecraft.
Transport to and install in Ceres underground.
Collect ice and hydrocarbons from the moons of Jupiter and Saturn, transport to Ceres using the moonmade spacecraft.
As things get really hot start collecting hydrogen form the solar wind.
During the worst part, consider a suspended animation trip, Noah’s ark style, to the Oort cloud and back.
After the planetary nebula, use fusion power to bring the Ceres ecosystem nearer the white dwarf as it cools.

I’m adding a timescale to the heating up of the Sun, and there are problems, long before we need to hollow out Ceres

The first problem is the problem of ‘Earth too hot, Mars too cold’

There is a slow rise in solar luminosity over the next 6.6 billion years. The problem is that Earth is too hot and Mars is too cold for a lot of that time. By the end of the slow heating, the surface temperature of Earth is about 90 degrees C, too hot. But Mars is still only -10 degrees censius on average.

A later problem is that Ceres is both too far and too near the Sun. It’s nicely pleasant on the surface for 60 million years, which is actually a really long time in the end times of the Sun, making it worth the effort. For most of the time it’s too cold. For 60 million years it’s way too hot on the surface of Ceres. For solar peak luminosity (Planetary nebula stage), Pluto and Triton are starting to look tempting. Or (as Neutrino suggests), hiding behind Jupiter. This deadliest of times only lasts 1 million years, which unfortunately is too short for Pluto or Triton to equilibrate and too short to move Ceres behind Jupiter.

The solution to the problem of ‘Earth too hot, Mars too cold’ is to either cool the Earth, heat Mars, live on the night side of the Moon, or live on a spaceship between Earth and Mars. Or all of the above.

Strategies for cooling the Earth include:

• Installing a parasol in space
• Changing the atmosphere
• Installing a reverse cycle air conditioner
• Stopping the Earth’s rotation and living on the night side

An alternative strategy to the use of Ceres as a spaceship is as follows:

• Plunder the Moon to make a ceramic moonship capable of carrying the Earth’s hydrosphere and atmosphere from Earth to Jupiter
• Strip off most of the Earth’s atmosphere and place on board this moonship
• Export the Earth’s biosphere to this moonship
• Strip off a significant fraction of the Earth’s hydrosphere and place on board this moonship
• Over the next 6.6 billion years, slowly increase the moonship’s orbit out half way to Mars
• Transport to the moons of Jupiter over the next 1 billion years
• Terraform the moons of Jupiter and collect nuclear fuel from them.
• Hollow out moons Amalthea and Himalia and move to Jupiter’s L2 lagrange point (using Jupiter to block the sunlight)
• Hide on Amalthea, Himalia, the moonship and in orbit around Triton and Pluto during the hottest phases of the Sun
• Seed ecosystems on Triton and Pluto
• After the planetary nebula, use fusion power to bring Amalthea, Himalia, and the moonship near the white dwarf as it cools.
  

Oops, no more than 1% of Earth’s hydrosphere can be lifted into space. It’d take too much energy to lift more.

Gosh. Are you sure sire?