Author Topic: Worldships  (Read 6994 times)

Offline lamontagne

  • Full Member
  • ****
  • Posts: 898
  • Liked: 1130
  • Likes Given: 206
Re: Worldships
« Reply #40 on: 02/17/2017 03:39 AM »
http://www.cbc.ca/news/technology/toronto-student-s-space-colony-design-wins-nasa-contest-1.821777
I was reminded of this by your mention of layered rings. As has been mentioned, this might be a useful interim step...

To the left side of the news article is a link to a detailed pdf (11mb) of the student's project...

Gramps

You can see all of the design for this contest here:
https://settlement.arc.nasa.gov/Contest/

As well as many excellent ressources (Actually, pretty much all available ressources!!) from this page:
http://space.alglobus.net/

The contest has been running for 20 years, and produced some great models.  I think its run by Al Globus.

These are all a little bit small for Worldships though, and usually dependent on solar power.

Offline Vultur

  • Full Member
  • ****
  • Posts: 1079
  • Liked: 147
  • Likes Given: 11
Re: Worldships
« Reply #41 on: 02/17/2017 06:37 AM »
I don't think the closed cycle problem for worldships would be terribly bad - usually they are discussed in the context of a few centuries, maybe a couple of thousand years at most.

Biosphere 2 is not a good example of the difficulties because it was designed terribly. Some of this may be hindsight, but there were some decisions that should have been obviously stupid at the time (desert next to rainforest next to ocean in 3 acres... right  ::) ... ) And in general they thought too much in terms of 'copying Earth's ecosystem' rather than in terms of processes. IMO even with what they knew at the time the oxygen issues could have been avoided if it was seriously analyzed in terms of cycles/processes. But the thinking behind Biosphere 2 was often not terribly scientific.

We could do far better.

Also, while Earth is big, some ecosystems on Earth are pretty isolated. Not completely, sure, but things like black smoker vent communities are largely disconnected from the global photosynthesis-driven ecology, at least on "short" (<100k years) time scales.

So there's no reason to think that small ecological systems inherently collapse. (Energy input from the Sun - EDIT: or chemicals from within the Earth - means it's not a closed system, so entropy needn't increase.) A worldship wouldn't have sunlight, but a fusion reactor would serve the same purpose.
« Last Edit: 02/17/2017 06:38 AM by Vultur »

Online KelvinZero

  • Senior Member
  • *****
  • Posts: 3311
  • Liked: 407
  • Likes Given: 94
Re: Worldships
« Reply #42 on: 02/18/2017 06:38 AM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.

If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.

That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

It doesn't solve issues of gravity for health, but there are many different ways to solve that and also to just avoid the problem by adapting your inhabitants. This is a world. You could have all these solutions and experiments going on at once. Spinning habitats above and below the ice. Different variations of humans living side by side, or some on the surface and some living many kilometers down under crushing pressures.

Moving even a dwarf planet obviously would require massive engineering, but you can start small with little colonies and just grow. You are not going to worry about moving the thing until it is entirely converted and does not itself contain new territory in its own right. It is basically a deathstar with huge fusion powerplants at that point.

Offline MikeAtkinson

  • Full Member
  • ****
  • Posts: 1614
  • Bracknell, England
  • Liked: 381
  • Likes Given: 50
Re: Worldships
« Reply #43 on: 02/18/2017 10:12 AM »
Maybe the way to use World Ships is to look for an object already going in the required direction and then building a colony on that.
There are many stars and objects which have been pushed into strange high speed paths, probably by collisions of galaxies.
As these will need to maintain life for  possibly thousands of years , looking for a star with planets that has been pushed on to a path maybe the way to go.
Another interesting possibility is to move from rogue planet to rogue planet.  The appear to be a number of these, with an average distance that might be as small as a light year apart.
If  the worldship can last, then colonies are perhaps not the best offspring for them.  Perhaps worlships build other worlships.

Even better is the Oort cloud, perhaps a billion objects bigger than 20 km in diameter, although mainly made of ices, objects that size would contain millions of tonnes of metals. It is quite possible for a worldship to replicate at these larger Oort cloud objects (there are 3 orders of magnitude more smaller objects in the Oort cloud that could be used for refueling and replenishment.

The larger objects would average about 0.002 light-years (about 130 AU) apart
So a world ship travelling at under 0.002% of the speed of light (no exotic propulsion necessary) could hop from object to object, visiting a new one every 100 years or so, replicating into a swarm over thousands of years.

Offline chalz

  • Full Member
  • *
  • Posts: 167
  • Austrangia
  • Liked: 77
  • Likes Given: 965
Re: Worldships
« Reply #44 on: 02/24/2017 06:20 AM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.

If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.

That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

It doesn't solve issues of gravity for health, but there are many different ways to solve that and also to just avoid the problem by adapting your inhabitants. This is a world. You could have all these solutions and experiments going on at once. Spinning habitats above and below the ice. Different variations of humans living side by side, or some on the surface and some living many kilometers down under crushing pressures.

Moving even a dwarf planet obviously would require massive engineering, but you can start small with little colonies and just grow. You are not going to worry about moving the thing until it is entirely converted and does not itself contain new territory in its own right. It is basically a deathstar with huge fusion powerplants at that point.
Love this idea. The ocean could be used as reaction mass to get the planet moving. Couple of kilometres off the top would be a vast volume and (having not done the maths) would give a small but useful velocity. Perhaps to slingshot off the 'birth' star for more speedl.

It interests me how the people would evolve on such a world. In some ways it seems to be the opposite of the 'make life interplanetary' mantra since you effectively isolate yourself. Unless you pointed yourself at a destination star, just wandering aimlessly seems an odd way to start a journey. Or perhaps that is over-analysing since the Earth is 'wandering aimlessly' but nobody worries about it.

Online gospacex

  • Senior Member
  • *****
  • Posts: 3017
  • Liked: 524
  • Likes Given: 598
Re: Worldships
« Reply #45 on: 02/24/2017 03:51 PM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.

If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.

That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

It doesn't solve issues of gravity for health, but there are many different ways to solve that and also to just avoid the problem by adapting your inhabitants. This is a world. You could have all these solutions and experiments going on at once. Spinning habitats above and below the ice. Different variations of humans living side by side, or some on the surface and some living many kilometers down under crushing pressures.

Moving even a dwarf planet obviously would require massive engineering, but you can start small with little colonies and just grow. You are not going to worry about moving the thing until it is entirely converted and does not itself contain new territory in its own right. It is basically a deathstar with huge fusion powerplants at that point.
Love this idea. The ocean could be used as reaction mass to get the planet moving. Couple of kilometres off the top would be a vast volume and (having not done the maths) would give a small but useful velocity.

Well, this does not seem to work. Even with a huge Isp of 0.1c, I'm getting very pessimistic numbers. For example, if 1% of the worldship launch mass is used up as reaction mass, I get below 300 km/s velocity.

Offline sanman

  • Senior Member
  • *****
  • Posts: 3517
  • Liked: 403
  • Likes Given: 1
Re: Worldships
« Reply #46 on: 02/25/2017 08:50 AM »
How about converting a comet or a Kuiper Belt object to do something vaguely similar?

When you're already farther out in the Kuiper Belt or the Oort Cloud, how much benefit does that give you on escape velocity?

Online KelvinZero

  • Senior Member
  • *****
  • Posts: 3311
  • Liked: 407
  • Likes Given: 94
Re: Worldships
« Reply #47 on: 02/25/2017 09:57 AM »
Well, this does not seem to work. Even with a huge Isp of 0.1c, I'm getting very pessimistic numbers. For example, if 1% of the worldship launch mass is used up as reaction mass, I get below 300 km/s velocity.
If you want to compete with those extreme machines that carry most of their mass in specialised nuclear fuel, then the endpoint of your processing of your worldship would have to pretty much be one of those extreme machines.

What you could get with a percent of your mass is probably a much tidier Oort cloud. I have heard estimates there might be 10,000 dwarf planets out there, but spread over a huge range. Maybe you want them all in a ring or closer to home or something.

You could also just diffuse through the galaxy. One of the problems of the Fermi paradox is that you don't need to postulate any significant speed at all. Just opportunistic hopping to passing worlds should have allowed colonisation of the entire galaxy by now, if any race had achieved open ended expansion.

Someone probably could produce a good estimate for the plausible ISP of a fusion engine that uses water both for it's fuel and propellant mass. It is not going to be as good as a vehicle carrying specialised fuel. And nothing beats exploiting the sun somehow: lasers around the sun, or mass itself projected from the sun at great velocity. If your goal is huge speed in something the size of a world, I think you probably want to exploit the sun somehow.

For my worldship, I was more just thinking along the lines of a world that has the resources to sustain life for million of years and is not bound to this solarsystem. Rather than setting out on a mission to another star, the question is more how far it would have to travel to encounter another similar sized rock to colonise.

Another question that interests me is what sort of nucleosynthesis is plausible starting with not much more than a ball of ice. If you are just endlessly detonating H-bombs in the core or somewhere would you end up producing other useful elements? Or would you use up the tiny fraction of deuterium in the ice and then not really be able to do anything with the rest?

Offline Paul451

  • Full Member
  • ****
  • Posts: 1179
  • Australia
  • Liked: 575
  • Likes Given: 496
Re: Worldships
« Reply #48 on: 02/28/2017 12:38 AM »
Eternal life! Human life time is increasing by X months every year now, and it is a long and accelerating trend.

Actually, in the US, in the last year with solid stats, 2015, the trend went backwards for the first time in decades. And the last several years have added just one net day to the average lifespan.

Long before that, the productive human lifespan hadn't extended in decades. Even in countries with longer lifespans, they've only lengthened the "last decade", as it were, rather than delaying it. We are only adding more senescence rather than more "life".



As has already been stated, replenishment of consumables of all types, is a necessity for the Worldship concept to work.
No, it is not a necessity. Earth does not need to replenish anything for 4.5 billion years already. All it needs is solar energy.

Actually it does, the most fertile parts of Earth are areas that deposit sediment eroded from recent uplift. The "new" material may come from inside the Earth (along with recycled crust), but that is an entire planet's worth of "storage" of new elements. Something that a much more mass-efficient Worldship would lack.

(Mass of the Earth = ~6e24kg. Even if 1/10th of 1% is considered of use, and spread out over 4.5 billion years, that's 1.3 billion tonnes of material per year available for consumption. "Sometimes quantity has a quality all of its own.")

((Of course, with 7 billion humans, that's around 190 kilograms per person per year. There's some natural recycling within the biological ECLSS, of course, but we may perhaps be exceeding our personal allotment a little.))

Offline Paul451

  • Full Member
  • ****
  • Posts: 1179
  • Australia
  • Liked: 575
  • Likes Given: 496
Re: Worldships
« Reply #49 on: 02/28/2017 12:45 AM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.
If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.
That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

In that scenario, I don't think you'd be trying to make World-ships, they'd just be Worlds. Settlements. Smaller "torch-ships" (assuming fusion) would move between them for trade, migration, etc, but I doubt they'd move the Worlds themselves (other than a minor tweak, perhaps, to match orbits with important trade or cultural partners.)

That's why I prefer asteroid colonisation as a "next step" rather than either Martian colonisation or O'Neill colonies. If there is anything that allows an asteroid settlement to pay for itself, then it will be a naturally expanding, self-reinforcing, self-"replicating" system. You only need a way in, that one first profitable settlement, and then by definition you already have sufficient technology to colonise the entire inner solar system. Each improvement in technology after that, faster ships, better power generation, tighter ECLSS, etc, not only improves the viability of existing settlements, but expands the limits that people can reach in the outer solar system. Over time, you get vast eco-systems of settlements, creating massive redundancy and resilience. But all paying for itself as it goes, like human expansion across Earth, with no grand Vision required to keep it going.

By the time you've reached the Kuiper Belt, the vast bulk of the economy will be independent of Earth. No further input from Earth is required for the process to continue expanding into the Oort Cloud (and, if technology permits that, beyond.)

(Colonising Mars, OTOH, emphasises technology needed to colonise Mars. Which is going to be unique to Mars. There's no natural expansion of capability, technology, and resources to settle anywhere else in the solar system; other then the systems of transport to/from Earth, which will tend to stay focused on Earth, rather than optimise for space-to-space transit. O'Neill colonies seem even worse.)

...
The ocean could be used as reaction mass to get the planet moving. [...]
In some ways it seems to be the opposite of the 'make life interplanetary' mantra since you effectively isolate yourself. Unless you pointed yourself at a destination star, just wandering aimlessly seems an odd way to start a journey.

Any multi-generational Worldship capable of reaching another star system has the technology necessary to not need to enter the star system, only brush against the occasional resources of an Oort Cloud. (This is the case whether it's a Worldship or the incremental outward settlement described above.) The bulk of human civilisation will exist outside heliopause, with no reason to approach any closer. Hence it doesn't matter which way you're going.

Online KelvinZero

  • Senior Member
  • *****
  • Posts: 3311
  • Liked: 407
  • Likes Given: 94
Re: Worldships
« Reply #50 on: 03/03/2017 11:27 AM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.
If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.
That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

In that scenario, I don't think you'd be trying to make World-ships, they'd just be Worlds. Settlements. Smaller "torch-ships" (assuming fusion) would move between them for trade, migration, etc, but I doubt they'd move the Worlds themselves (other than a minor tweak, perhaps, to match orbits with important trade or cultural partners.)
Yeah I think we will keep finding ways to avoid moving large masses: eg uploaded personalities, nanoscale replicating probes..

It is something I don't worry about much because so many possibilities arise after we have some self sufficient colonies. Get to that point and some future humanity will sort this all out. No need to worry about those sorts of details now.

I think in the far future there might be reasons to get large masses moving at large velocites but it would be a permanent thing. You would never stop at your destination. You might drop nano probes as you fly by but there is so much effort getting to that velocity, such wasted effort stopping, so much advantage from keeping that velocity.

Offline lamontagne

  • Full Member
  • ****
  • Posts: 898
  • Liked: 1130
  • Likes Given: 206
Re: Worldships
« Reply #51 on: 03/05/2017 06:54 PM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.
If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.
That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

In that scenario, I don't think you'd be trying to make World-ships, they'd just be Worlds. Settlements. Smaller "torch-ships" (assuming fusion) would move between them for trade, migration, etc, but I doubt they'd move the Worlds themselves (other than a minor tweak, perhaps, to match orbits with important trade or cultural partners.)
Yeah I think we will keep finding ways to avoid moving large masses: eg uploaded personalities, nanoscale replicating probes..

It is something I don't worry about much because so many possibilities arise after we have some self sufficient colonies. Get to that point and some future humanity will sort this all out. No need to worry about those sorts of details now.

I think in the far future there might be reasons to get large masses moving at large velocites but it would be a permanent thing. You would never stop at your destination. You might drop nano probes as you fly by but there is so much effort getting to that velocity, such wasted effort stopping, so much advantage from keeping that velocity.
It's pretty hard to resupply at high velocity.  The interstellar medium is ressource poor, to say the least.
An intriguing notion is the possibility of hopping from rogue planet to rogue planet.  This would allow a worldship to move much more slowly, but still find ressources to resupply itself and would be a rather natural extension of Oort cloud comet hopping.  I would expect a worldship to tend to reproduce each time it came into contact with a planet or solar system, just a outlet for growth and to keep the possibility of leaving the vehicle open.  It seems like a natural extension of how life already operates.
In a sense the worldship is an organism, carrying happy little symbiotes in the shape of humans :-)

Offline qraal

  • Full Member
  • *
  • Posts: 141
  • Liked: 53
  • Likes Given: 17
Re: Worldships
« Reply #52 on: 03/05/2017 07:35 PM »
Dandridge Cole called them 'Macrolife'. Seems fitting.

Offline llanitedave

  • Senior Member
  • *****
  • Posts: 2075
  • Nevada Desert
  • Liked: 1255
  • Likes Given: 1449
Re: Worldships
« Reply #53 on: 03/06/2017 01:44 AM »
Just wanted to insert my pet idea of converting dwarf planets to ocean worlds under protective eggshells of ice.
If you have mastered fusion power (even primitive fusion power such as building and detonating H-bombs) and you live under the ice and dump your waste heat there this would happen sort of naturally.
That makes an entire world your self-repairing gas tank. You could make a world-ship from that, easy.

In that scenario, I don't think you'd be trying to make World-ships, they'd just be Worlds. Settlements. Smaller "torch-ships" (assuming fusion) would move between them for trade, migration, etc, but I doubt they'd move the Worlds themselves (other than a minor tweak, perhaps, to match orbits with important trade or cultural partners.)
Yeah I think we will keep finding ways to avoid moving large masses: eg uploaded personalities, nanoscale replicating probes..

It is something I don't worry about much because so many possibilities arise after we have some self sufficient colonies. Get to that point and some future humanity will sort this all out. No need to worry about those sorts of details now.

I think in the far future there might be reasons to get large masses moving at large velocites but it would be a permanent thing. You would never stop at your destination. You might drop nano probes as you fly by but there is so much effort getting to that velocity, such wasted effort stopping, so much advantage from keeping that velocity.
It's pretty hard to resupply at high velocity.  The interstellar medium is ressource poor, to say the least.
An intriguing notion is the possibility of hopping from rogue planet to rogue planet.  This would allow a worldship to move much more slowly, but still find ressources to resupply itself and would be a rather natural extension of Oort cloud comet hopping.  I would expect a worldship to tend to reproduce each time it came into contact with a planet or solar system, just a outlet for growth and to keep the possibility of leaving the vehicle open.  It seems like a natural extension of how life already operates.
In a sense the worldship is an organism, carrying happy little symbiotes in the shape of humans :-)

By that point in evolution, I suspect the descendants of humans would have long since ceased retaining the shape of humans.
"I've just abducted an alien -- now what?"

Offline lamontagne

  • Full Member
  • ****
  • Posts: 898
  • Liked: 1130
  • Likes Given: 206
Re: Worldships
« Reply #54 on: 03/06/2017 01:38 PM »
Dandridge Cole called them 'Macrolife'. Seems fitting.
Very interesting reference.  I read Beyond Tomorrow about 25 years ago, in a public library in a small town way up north called Rouyn-Noranda, where I was the first person to take out the book in over a decade.  And was amazed by how much had been anticipated.

The only technical point I would like to raise about asteroids as starships is that I believe the ideas of mr. Cole had evolved by the time he wrote his last works, and that the final versions of the asteroid starships were built from metal asteroids expanded into shells using mirrors and steam pressure.  So the rocky outside look used in the illustrations would have been replaced by bright shiny stainless steel surfaces.  I don't recall seeing any visual expression of this though.

Tags: