Kardashev's classes of civilizations are spread across type 0 to type III. Types IV and V have been added in recent years and ambiguity has been introduced into their definitions. In this thread I wish to stick with definitions constrained to hadronic matter and levels of organization within the observable universe. I.e., let's stay away from definitions involving string theories, brane theories, and hyper-dimensions.

http://home.comcast.net/~mbmcneill7/ includes a method of interstellar travel and the acquiring of the propellant and energy to do so which I believe is the first step in a sequence of gradual improvements that can propel humans to a type V staus within a million years. I won't object to defining a type VI civilization as one capable of black hole management.

Please provide comments---especially those in opposition.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Not to be too awkward but i dont understand how you can make a million year plan that will not be wildly out of date within 500 years. I would suggest that any interstellar craft we are capable of making in the next few thousand years will be made redundant by newer technology a few thousands later.

We need to at least get to a technological level where developing a "comfortable" interstellar probe is not a serious challenge. Either the system for propulsion has to be able to reach 80% of c, or the highest threshold speed where mass does not become a major problem which i think is around the mass doubling at 87%? Or if we cannot develop such propulsion system then we need to be able to build a very habitable craft which can carry generations of humans on long jouneys with a very high degree of safety and self-dependence.

You should think of the million year "deadline" as a target for a more modern system to beat. The system described can reach above 0.9 c and give us access to resources far beyond the limited supply available here in the solar system. I believe that a system powered by power beams formed near a star is the only feasible way to go interstellar, and through continuous improvements to the basic concept will lead us (via our progeny) to a type VI civilization. I will be overjoyed to learn about a better system defined at an equivalent level.

If you're thinking in terms of wormhole and space folding exploitation, navigation and obstacle avoidance will be an overwhelming problem. Fission, fusion, and matter/anti-matter processes will likely require more mass than they produce energy to propel and still dodge the obstacles that clutter the paths between stars.

Try to evaluate the system, setting aside how much better future systems designed by smarter critters than I, will be as to whether it will support our evolution into a type VI civilization.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

"If you're thinking in terms of wormhole and space folding exploitation, navigation and obstacle avoidance will be an overwhelming problem. Fission, fusion, and matter/anti-matter processes will likely require more mass than they produce energy to propel and still dodge the obstacles that clutter the paths between stars."

I'm not really sure of any of those technologies. However i was under the impression that both matter/antimatter annihilation propulsion and fusion propulsion would all generate far more energy than that which is necessary as fuel. Perhaps i am misinformed on that one.

They each will generate large amounts of radiation and heat which would have to be used to power ion engines. In the case of fusion, the fusion products could be used for propellant if we can capture and control them after fusion and feed them into the ion propulsion process. In the case of matter/anti-matter combination the propellant candidates are limited to neutrinos and photons for which we don't have the efficiency robbing focussing technology required for propellants. In each of these cases I expect the mass of shielding and "input fuel" to be insurmountable.

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Antimatter annihiliation would produce enough energy for interstellar flight, but it has several disadvantages. Firstly antimatter is extremely difficult and expensive to create; it would take millions of years at the current rate of production to make enough for a flight to Mars, let alone a flight to the stars.
Secondly much of the energy released in an antimatter reaction is released as gamma-rays or neutrinos- neither of which can be reflected by any known material, so they can't be used to produce thrust.

In short the antimatter option is very, very inefficient and costly, unless several highly speculative advances in technology are possible.

Fusion power is barely powerful enough to get to a distant star in a reasonable time- but if you want to slow down at the destination, you need to take vast amounts of fuel with you. So it is effectively impractical as well.

Gourdhead's idea of beamed power seems to be one of the few feasible schemes for interstellar travel, but it has some drawbacks too. The beam can only accelerate a ship; to decelerate at the destination you need on-board fuel, or another power beam/particle beam already at the destination to slow you down. Basically you need a beam station at every departure and arrival point. Secondly- a minor nitpick- the ship should be symmetrical, around the centre of thrust- otherwise the beam would tend to push the craft sideways, out of the beam, losing power.

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In the middle ages (I maybe wrong about this...) they had earnest discussions about how many angels could dance on the head of a pin. (You may substitute any other un-verifiable, un-testable topic you like)

I think efforts to plan technologies more than a decade or so ahead are doomed to be irrelevant. We need to get out of the cradle before we start wondering what running shoes we will be using.

Lets work out what steps we can take in the immediate future to get to the point where we can sustain colonies off-earth first. Then we will find that we have enormous resources available right here in our own solar system. By the time we need to start to worry about system resource depletion we will already have a whole range of new technologies to consider for the next step.

Gourdhead I would suggest that your efforts are better spent on finding a more immediate problem... the far future will likely look a lot different than you or I imagine it to be.

Thanks for the suggestion; however, I decline to take it. If you take a serious look at the concept, you'll realize that it is needed to terraform/colonize sites within the solar system and if we find useful resources at other sites and have developed a sufficiently robust infrastructure to acquire the resources we shall have folllowed a concept very similar to the one proposed. The steps to take in the immediate future are ones to implement the concept. We can't guess how soon the comet/asteroid destroyer/deflector feature of the concept will be required. Remember the set of systems required by this concept will take ~500 years to emplace. I would be very pleased to review an outline of systems of which you are aware that address the solution to near term problems associated with space exploration.

Good point. However, the ion engines will keep the power receiver centered on the beam, but at a loss of efficiency. The fix I have been thinking about is to add one to three additional thrust modules around the circumference of the power receiver to achieve thrust symmetry with respect to the beam.

Stopping the vehicle at the destination will be achieved by reversing the ion engine thrust.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Ah, I thought so. That means you have to take propellant with you, even though your ship doesn't require fuel That would work, but you should be aware that the amount of propellant required to decelerate from interstellar speeds is considerable. That would increase the mass of the ship in flight, and therefore the energy required to get it up to speed.

A more efficient scheme (once you can set up the infrastructure required) would be to have a beam station at each end of the route, one to accelerate the ship and one to decelerate it. The ship itself needs no on-board propellant at all; you fire small, massive particles (that is to say particles with mass) at the ship to acccelerate or decelerate it. This is a way of transferring momentum to a distant craft. One method (suggested by Isaac Kuo on this forum) is to accelerate innumerable tiny foil light-sails toward the craft; they would vapourise on contact with the ship and impart thrust to it.

Once you have beamstations on all the local stars you can send spacecraft from system to system relatively efficiently.

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Well i would not want to dampen any hopes because i too am impatient for humans to start getting serious about interstellar space. The problem is until we make some big advances we remain far too succeptible to catastrophes.

I think Gourhead's ideas are great for building ourselves into a civilisation technologically powerful enough to accomplish interstellar flight, but I do think the propulsion technology will be difficult to time becuase in some ways we dont even know what is possible, or whether there is some great new technology around the corner which would completely transform the challenge. Remember we are humans, and one can imagine the problems there will be in future getting funding for these types of programs, unless its sold to the public as clean energy..for instance.

This kind of program will be swamped by petty politics and dogma - unfortunately.

about decelerating - can't you do a lot of that just by going in to orbit around something big when you arrive (and switching off the thrust ofc)?
But what do I know?
Presumably you'd have to have another means of local manouevering anyway?

And maybe you sometimes wouldn't even aim at the star you were heading for. Maybe sometimes it would be better to "slingshot" round something else on the way, where you could lose, or gain, momentum.

And couldn't you steer a bit with angled deflectors? (as long as the beam moved with you ofc)

No. At interstellar speeds you would enter a hyperbolic orbit, which would simply carry you away from the star in a diferent direction. In fact the amount of deflection would probably be minimal, unless you manage to find an object with a very strong gravity field, like a black hole. In which case the change of course would be a very uncomfortable experience for you and your ship.
See above. The slingshot effect would be minimal at interstellar speeds (depending on your mass, of course). I've thought about this possibility in connection with binary stars- but the deceleration you would get would be mimimal in most cases.
Yes. Or you could use a mirror. Robert Forward designed a deceleration configuration for his Starwisp concept (see this image)
http://www.transorbital.net/Library/D001FA02.GIF
using a ring-shaped mirror reflector travelling in front of the sail: but this configuration would require very tight beams, and very lightweight payloads, to work.

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Thank you, see, I said I knew nothing

If one trajectory takes you away in a hyperbolic path and another crashes you in to the star, why isn't there one in between that puts you in orbit?
Is it just because you are going too fast?

My plan for decelerating is to reverse the oreintation of the ion engines. Having a power beam at the destination star system can't be implemented until we reach the stellar system. My hope is that we can steer a particle beam such that particles, mostly hydrogen, will be distributed along the path to be taken by the interstellar vehicle thus enabling it to gather propellant as it goes. Remember the main motive force for the vehicle is the set of ion engines, not the sail effect.

Aiming the beam which the vehicle follows will be a challenge. We have to aim where the star will be when we get there, so we want to be able to accurately predict how long the trip will take. As for maneuvering the vehicle at the destination, a lot of detail has to be worked out. A portion of the photovoltaic panels in the power receiver must be designed to be easily removed and set up (or a prefabricated set must be included as payload) to provide power locally. A fission based auxiliary power supply may be required.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

I have no problem with starwisps for fast flyby--but the long, slow automated generation starship is what you need to get real resources into the universe.

Actually, I disagree. The concept of a generation ship requires a very large vessel , capable of supporting a breeding population of humans for thousands of years; all their food needs to be grown or manufactured on-board, and all their waste materials recycled. That implied a payload of millions of tonnes to be accelerated to interstellar speed.

At the other end of the scale the Starwisp is too small. It could barely carry a TV camera, let alone a human.

What is required is something in-between, a ship capable of delivering a sizable payload of manufacturing equipment to a system, which can then start making the requirements for a colony on arrival. No living people need be carried at all; they can be instead carried as zygotes, or gametes, or just as digitised DNA; human embryos could be raised to term in artificial wombs and raised by robots at the destination.

This might seem far fetched- but by the time we are able to manufacture starships, most or all of these other technologies will likely be available too. If they are, I would expect that no generation ships would ever be built.

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Maybe. In both cases all the infrastructure required to continue a self sufficient society must be sent to another solar system, and in both cases at the end of the journey there needs to be an environment humans can live in. The generation ship might well contain a great deal of dual use hardware that would go towards expanding infrastructure at the destination. The automation in the second option might well ending up massing more than would the generation ship option. Also, if automation is that good, is there a point in sending people?

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Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

Not imediately at the end of the journey. The interstellar vehicle (or fleet of them) must contain enough "tools and equipment" to even build planets (at least minor planets) since our beam collimation skills may constrain the length of our path segments through the galaxy such that we have to use planetless stars as "stepping stones". Also, the safer planets on which to initiate colonization will be those without life, although finding an earthlike planet in a stage of evolution as was the Earth 50 million years ago might be manageable. Although visits between colonized star systems will be much more easily accomplished as beam generators are installed at each star, I don't expect much mutual visiting except to avoid emergencies as some system is in danger of bein deastroyed.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

The embryo stuff ... I'm not sure. I think it would be easier to build a generation ship than an AI competent enough to raise functional humans. Human parents find it very difficult; and how much of it do we do instinctually, or take for granted, that we wouldn't know to program in?

A generation ship just requires the ability to move lots of mass in space. It's still far away, but I think it requires a lot fewer technologies that we don't understand. A competent enough AI to raise human children is so far beyond anything possible now as to require lots of radically new knowledge; a generation ship would mostly be larger scale applications of technology we understand in principle.

Virtual Reality, Artificial Intelligence, and android skills may even be how terrestrial kids could be raised in a not inconceivable future. Hell, just send/build androids...

The first step is rocket fuel production somewhere closer to orbit.
The second step is fusion technology
The third step is fusion powered factories making anti-matter
The forth step is a probe
The fifth step is an automatic factory/station to receive the visitors
The sixth step is sending the colonisers.

So we need much better automation, as well as tons of cheap energy ...and possibly some new definitions as what constitutes a representation of human/solar society.

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plenty of woo, at the hotel hoagaland...

A generation ship is a self contained artificial world, if we can build them, do we really need a destination? The crew might decide that roaming the galaxy was a better option than colonising a planet, and just wander away. And who could blame them?

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I'M WRITING UP MY THESIS AND BECOMING A DAD SOON. I'LL BE BACK IN SUMMER TO AUTUMN 2010.

For me it's enough for the garden to be beautifull; why do so many want to see fairies at the bottom?

"Many of those people are not getting four when adding two and two; many of them aren't even getting five or twenty-two. They're getting potato."
Gillianren

True. But a planet with life would be irresistible to explore and study.

A generation ship could exist for a very long time on the energy required to decelerate at its destination. After a journey of thousands of years, some generation ships might decide not to slow down...
(here's a story I've written about this theme)

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Exactly. If you didn't start out in orbit of a body, simply falling towards it under the influence of gravity won't put you in orbit- the gravity field doesn't change your energy in relation to it, it just converts potential energy to kinetic energy and then back. You'll pass by it and eventually get to the same distance and speed that you started with. An orbit works the same way, but if your velocity is high enough the gravity well won't actually stop you and complete the ellipse- that is a hyperbolic path. Whether you hit the star or not in this case is not a factor of velocity but of direction- if your path goes through the star, you go splash, and if not, you continue on. To enter orbit, you would need to change your velocity, slowing in relation to the star. Aerobraking at such speeds (using a star or planet's "atmosphere" to slow down via classic friction) would be be, shall we say, problematic.

Mike