Pros and Cons of Various Methods of Interstellar Travel

It’s a staple of science fiction, and something many people have fantasized about at one time or another: the idea of sending out spaceships with colonists and transplanting the seed of humanity among the stars. Between discovering new worlds, becoming an interstellar species, and maybe even finding extra-terrestrial civilizations, the dream of spreading beyond the Solar System is one that can’t become reality soon enough!

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Watched Ghost in the Shell the other day, the new movie with S.J.

Good movie, its about the life of a young woman whose brain was put into a robots body.

The next step would be putting a brain into a chip with A VR environment to live in.

Imagine if you could put your mind, memories, your “self” into a chip, you live, sleep, work, play, and dream in a VR environment.

Imagine doing that to 7 billion people with their minds all on chips for long voyage into space on a space ship.

That’s how you move a whole population to another planet when our star goes Red Giant Phase.

> That’s how you move a whole population to another planet when our star goes Red Giant Phase.

If you only transport fertilised ova or embryonic stem cells then Earth’s entire ecosystem will fit in a mass of 1 kg.

That’s how you move your whole ecosystem.

mollwollfumble said:

> That’s how you move a whole population to another planet when our star goes Red Giant Phase.

If you only transport fertilised ova or embryonic stem cells then Earth’s entire ecosystem will fit in a mass of 1 kg.

That’s how you move your whole ecosystem.

That’s one way of getting rid of the kids.

It’s going to take me a while to get through the references from that news article, repeated below.

In the meantime, ignore FTL. FTL is not physically impossible, but it is technically impossible.

Also forget multigenerational ships. Not physically or technically impossible. Financially impossible.

> five principle means for mounting crewed missions to other star systems in his study. These include super-luminal (aka/ FTL) travel, hibernation or stasis regimes, negligible senescence (aka. anti-aging) engineering, world ships capable of supporting multiple generations of travellers (aka. generation ships), and cyrogenic freezing technologies.

He missed the possibility of high sublight speed. At high sublight speeds, the Lorentz contraction reduces the distances to the stars enormously. For example, The Lorentz contraction reduces the 27 km length of the LHC to just 3.6 metres, as seen by a circling proton. Applying the same ratio of 7,500 to the distances between stars we have a flight to Proxima Centauri taking only 0.2 days shipboard time.

a recent study

“How Long Would it Take to Travel to the Nearest Star?“:https://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/

hibernation and stasis

anti-aging cream

> Last, there is cryogenics

“Cryogenics” is correct, but far too many people use the word “cryogenics” wrongly when they actually mean “cryonics”.

Why do you think multigenerational ships are financially impossible? Because no nation or coalition of nations wouldn’t fund one?

AwesomeO said:

Why do you think multigenerational ships are financially impossible? Because no nation or coalition of nations wouldn’t fund one?

Molwoll is limited to his fields of knowledge.

Simple arithmetic. We all are, which is why our combined awareness is leading somewhere.

Oops, would fund one.

AwesomeO said:

Oops, would fund one.

Lotsa people would.

AwesomeO said:

Why do you think multigenerational ships are financially impossible? Because all most nations or coalition of nations wouldn’t fund one?

better?

AwesomeO said:

Why do you think multigenerational ships are financially impossible? Because no nation or coalition of nations wouldn’t fund one?

More than that.

Fine. Let’s calculate a cost. Start with a minimum of $1,000 per kg into orbit, that’s a low figure but in the right ballpark. That’s a fixed figure, no amount of technology improvement is going to improve on that. By way of comparison, the International Space Station cost $150 billion and weighs 450 tons, so cost to orbit there was $300,000 per kg.

A working ecosystem to support the humans … Biosphere 2 had a 2,500-square-meter agricultural system and a human habitat with living spaces, laboratories and workshops. Plus an extra 10,200 square metres of non-agricultural land for oxygen generation. In total 180,000 cubic metres. That’s for a crew of 8, where 83% of the total diet came from agriculture. Even that turned out not to be large enough, there were severe food and oxygen shortages in just two years. Looking further into information, it lasted just 16 months before oxygen levels had dropped so far that extra oxygen was added, so that was essentially the end of the experiment so far as spaceflight was concerned.

Let’s look at the paper Overview and Design. Biospherics and Biosphere 2, mission one.

The original concept for Biosphere 2 was much more ambitious in terms of small size. Originally they aimed for 200 cubic metres of breathable atmosphere, soon enlarged to 480 cubic metres. Originally they aimed for 100% diet from agriculture, quickly reduced to 81% of the diet for eight humans on 2,000 square metres on an average outside sunlight of 40 moles of photons per square metre per day. Then it was expanded to what I’ve written above. Diets were calorically restricted.

For a multi-generational craft, relying solely on stored food such as on a nuclear submarine is not an option. Nuclear submarines run out of food in 90 days.

How much would a minimal active biosphere for a multigenerational craft weigh? One hell of a lot. It would require a huge amount of power to accelerate to any useful speed, even if the power was supplied by nuclear fusion.

I’ll think more on this.

mollwollfumble said:

.

Fine. Let’s calculate a cost. Start with a minimum of $1,000 per kg into orbit, that’s a low figure but in the right ballpark. That’s a fixed figure, no amount of technology improvement is going to improve on that. By way of comparison, the International Space Station cost $150 billion and weighs 450 tons, so cost to orbit there was $300,000 per kg.
.

What about space elevators?

Cheers, moll, one of the “affordable” options I was thinking of the new speculative trend of harnessing an asteroid for its resources, especially water and using that as a space craft. Agreed constructing a ship that contains everything would be prohibitive but a suitable asteroid could be mined as you go, not so much lifted into orbit.

Though I do now in my mind, have a sort of sci fi vision of a few generations later a sort of patched up space scavengers scenario. It may be that a generational ship is not possible because unless you have a big enough population base the knowledge resources to overcome and adapt are not there.

Or another vision, a sort of steam punk space scavengers, reasonably low tech so everything can be fabricated and remade.

Witty Rejoinder said:

mollwollfumble said:

.

Fine. Let’s calculate a cost. Start with a minimum of $1,000 per kg into orbit, that’s a low figure but in the right ballpark. That’s a fixed figure, no amount of technology improvement is going to improve on that. By way of comparison, the International Space Station cost $150 billion and weighs 450 tons, so cost to orbit there was $300,000 per kg.
.

What about space elevators?

Not on Earth. Or to put it another way, if you did make a space elevator on Earth then it would still cost more than $1,000 per kg to lift mass into orbit.

On Mars, space elevators make more sense because the rotation speed is the same as Earth’s but the gravity is less.

AwesomeO said:

Cheers, moll, one of the “affordable” options I was thinking of the new speculative trend of harnessing an asteroid for its resources, especially water and using that as a space craft. Agreed constructing a ship that contains everything would be prohibitive but a suitable asteroid could be mined as you go, not so much lifted into orbit.

Wasn’t thinking that. But for an ecosystem carrying of order 1,000 people rather than of order 20 people that makes sense. It’s even more expensive, but on a cost per person scale it would be better.

mollwollfumble said:

He missed the possibility of high sublight speed. At high sublight speeds, the Lorentz contraction reduces the distances to the stars enormously. For example, The Lorentz contraction reduces the 27 km length of the LHC to just 3.6 metres, as seen by a circling proton. Applying the same ratio of 7,500 to the distances between stars we have a flight to Proxima Centauri taking only 0.2 days shipboard time.

Did you like my idea of a 0.2 day long sub-light-speed journey to Proxima Centauri?

Can you explain to me why it wouldn’t work? LOL.

Hint. We couldn’t get faster than 0.1 times the speed of light with any currently conceivable combination of energy sources, no matter how small the vehicle mass. So the journey would have to take 42 years or more, which is much more doable.

Did they mention launch by railgun from the Moon?

mollwollfumble said:

AwesomeO said:

Why do you think multigenerational ships are financially impossible? Because no nation or coalition of nations wouldn’t fund one?

More than that.

Fine. Let’s calculate a cost. Start with a minimum of $1,000 per kg into orbit, that’s a low figure but in the right ballpark. That’s a fixed figure, no amount of technology improvement is going to improve on that. By way of comparison, the International Space Station cost $150 billion and weighs 450 tons, so cost to orbit there was $300,000 per kg.

A working ecosystem to support the humans … Biosphere 2 had a 2,500-square-meter agricultural system and a human habitat with living spaces, laboratories and workshops. Plus an extra 10,200 square metres of non-agricultural land for oxygen generation. In total 180,000 cubic metres. That’s for a crew of 8, where 83% of the total diet came from agriculture. Even that turned out not to be large enough, there were severe food and oxygen shortages in just two years. Looking further into information, it lasted just 16 months before oxygen levels had dropped so far that extra oxygen was added, so that was essentially the end of the experiment so far as spaceflight was concerned.

Let’s look at the paper Overview and Design. Biospherics and Biosphere 2, mission one.

The original concept for Biosphere 2 was much more ambitious in terms of small size. Originally they aimed for 200 cubic metres of breathable atmosphere, soon enlarged to 480 cubic metres. Originally they aimed for 100% diet from agriculture, quickly reduced to 81% of the diet for eight humans on 2,000 square metres on an average outside sunlight of 40 moles of photons per square metre per day. Then it was expanded to what I’ve written above. Diets were calorically restricted.

For a multi-generational craft, relying solely on stored food such as on a nuclear submarine is not an option. Nuclear submarines run out of food in 90 days.

How much would a minimal active biosphere for a multigenerational craft weigh? One hell of a lot. It would require a huge amount of power to accelerate to any useful speed, even if the power was supplied by nuclear fusion.

I’ll think more on this.

Perhaps a multigenerational spaceship is possible if it’s a last ditch effort to ensure the survival of humanity and cost isn’t important and the entire resources of the planet are put into play

Tau.Neutrino said:

Watched Ghost in the Shell the other day, the new movie with S.J.

Good movie, its about the life of a young woman whose brain was put into a robots body.

The next step would be putting a brain into a chip with A VR environment to live in.

Imagine if you could put your mind, memories, your “self” into a chip, you live, sleep, work, play, and dream in a VR environment.

Imagine doing that to 7 billion people with their minds all on chips for long voyage into space on a space ship.

That’s how you move a whole population to another planet when our star goes Red Giant Phase.

no

you swap your dying star with another suitable star in the galaxy in a split second

your star is put into retirement in the position of the star you swapped with

wookiemeister said:

Tau.Neutrino said:

Watched Ghost in the Shell the other day, the new movie with S.J.

Good movie, its about the life of a young woman whose brain was put into a robots body.

The next step would be putting a brain into a chip with A VR environment to live in.

Imagine if you could put your mind, memories, your “self” into a chip, you live, sleep, work, play, and dream in a VR environment.

Imagine doing that to 7 billion people with their minds all on chips for long voyage into space on a space ship.

That’s how you move a whole population to another planet when our star goes Red Giant Phase.

no

you swap your dying star with another suitable star in the galaxy in a split second

your star is put into retirement in the position of the star you swapped with

that’s how it’s normally done anyway.

wookiemeister said:

Tau.Neutrino said:

Watched Ghost in the Shell the other day, the new movie with S.J.

Good movie, its about the life of a young woman whose brain was put into a robots body.

The next step would be putting a brain into a chip with A VR environment to live in.

Imagine if you could put your mind, memories, your “self” into a chip, you live, sleep, work, play, and dream in a VR environment.

Imagine doing that to 7 billion people with their minds all on chips for long voyage into space on a space ship.

That’s how you move a whole population to another planet when our star goes Red Giant Phase.

no

you swap your dying star with another suitable star in the galaxy in a split second

your star is put into retirement in the position of the star you swapped with

Teleportation of stars is so next level.

Tau.Neutrino said:

wookiemeister said:

Tau.Neutrino said:

Watched Ghost in the Shell the other day, the new movie with S.J.

Good movie, its about the life of a young woman whose brain was put into a robots body.

The next step would be putting a brain into a chip with A VR environment to live in.

Imagine if you could put your mind, memories, your “self” into a chip, you live, sleep, work, play, and dream in a VR environment.

Imagine doing that to 7 billion people with their minds all on chips for long voyage into space on a space ship.

That’s how you move a whole population to another planet when our star goes Red Giant Phase.

no

you swap your dying star with another suitable star in the galaxy in a split second

your star is put into retirement in the position of the star you swapped with

Teleportation of stars is so next level.

blackholes in the wrong place are dealt with by a “time bomb”

a device that distorts time so it speeds time up is materialised into the heart of the sinugularity and the time rip or disparity between time zones causes a massive explosion

at the astral department some blokes write up a list of blackholes and star swaps that they think appropriate , run it through the computer and print the order for detonation or swap on an A4 sheet

the sheet is then presented to a resident dog (preferably a mongrel of some amusing variety) who then decides the order to be “valid”. if the dog sniffs at the sheet in a suspsiciously, tries to tear it up, bite the hand of the presenter or simply runs away the order is then declared “suspect” and the order is delayed for approval and sent back for recalculation.

wookiemeister said:

at the astral department some blokes write up a list of blackholes and star swaps that they think appropriate , run it through the computer and print the order for detonation or swap on an A4 sheet

the sheet is then presented to a resident dog (preferably a mongrel of some amusing variety) who then decides the order to be “valid”. if the dog sniffs at the sheet in a suspsiciously, tries to tear it up, bite the hand of the presenter or simply runs away the order is then declared “suspect” and the order is delayed for approval and sent back for recalculation.

I wonder if a way could be found to mine black holes for energy which then could be used for spaceships.

Imagine if you contain black hole energy.

Tau.Neutrino said:

wookiemeister said:

at the astral department some blokes write up a list of blackholes and star swaps that they think appropriate , run it through the computer and print the order for detonation or swap on an A4 sheet

the sheet is then presented to a resident dog (preferably a mongrel of some amusing variety) who then decides the order to be “valid”. if the dog sniffs at the sheet in a suspsiciously, tries to tear it up, bite the hand of the presenter or simply runs away the order is then declared “suspect” and the order is delayed for approval and sent back for recalculation.

I wonder if a way could be found to mine black holes for energy which then could be used for spaceships.

Imagine if you contain black hole energy.

I did include black hole energy in my calculation of possible intersteller drives, not that I think it’s possible. The energy of up to 40% of the matter falling into a black hole can be utilised for propulsion, in theory. There are various drawbacks including the impossibility of making a large enough black hole in the first place, containing it safely, accelerating that big a mass, spinning it up, directing the propulsion energy in the correct direction, and safely disposing of it at the end of the journey.

Now a reminder to myself that I haven’t read the articles on the following links yet.

a recent study

How Long Would it Take to Travel to the Nearest Star?

hibernation and stasis

anti-aging cream