Starflung

[gothwalk]

two_star asks good questions:

I guess I don't have a very clear idea of how easy spaceflight is in this Universe. There are several parameters:

How expensive is it to build an FTL ship?

The basic expense is getting stuff into Earth orbit. Moving the ship by conventional means to Martian orbit is not too tough, and the FTL drive is fitted there. Cost to orbit is currently around $10,000 per kilogram, I think. I'm going to assume that that drops to about half, even allowing for inflation over 44 years, so say $5000 per kg. That's still pretty expensive. I'll have to do some more calculations as to how much a colony ship needs to weigh, and we have to include the possibility of some materials and parts being manufactured on the moon or Mars, which have lower costs to orbit.

How expensive is it to travel a given distance?

I don't know. This is a poor answer, I realise, but I need to work out more of the physics involved, and I'm not sure how hard I want to make this sci-fi; I'm aiming more in a Space Opera direction. The basic question is whether FTL travel uses momentum or not - can you blast up to 40 times lightspeed, and then stay there until you brake, or do you have to keep supplying energy to overcome some form of friction?

How far can a ship can go without needing refueling and repairs?

Considering that Voyager got out of the Solar System still pinging, and there's little enough to run into in interstellar space, I'd say this is a pretty high number.

How much can a ship carry? (in terms of people, cargo, data.)

This can vary. A colony ship could be anything from the size of the ISS - not much of a colony, admittedly - upward. The "friction" question above may affect shape and size. Later utilitarian ships might potentially be any size.

How wealthy are colonies, (i.e., how many ships can they afford?)

I think that for some reason related to the drive, it's easier to build one two-million ton ship than two one-million ton ships. So the question is more like: How large a ship can they afford? Unless they want to send ships in more than one direction.

And what is the range of cultural priorities in terms of how starships are used, (colonization, luxury tourism, trade, exploration, warfare.)

At diaspora or after? At diaspora, colonisation only. Afterward, anything you can think of.

And aliens are a whole 'nother bundle of worms. What are they like? How do you resolve the Fermi paradox?

Aliens can be and are anything and everything. I dislike the Fermi paradox (it's boring, and it limits the horizons of a Space Opera setting), so I'm going to throw it out. Aliens have not come to visit us because we live inside the FTL limit in a backwater system in an out-of-the-way part of the galaxy.

As someone else (ezrael?) mentioned, most communication is by FTL pod; radio is too slow and too clumsy for interstellar communications. So that's why we haven't heard radio signals.

Comments

[juuro.livejournal.com]

I need to work out more of the physics involved

If you have FTL transport within one universe, you can choose any physics you like, arbitrate any cost you like.

But the implications of a starfaring civilisation are interesting to explore, even if it means having to suspend some of the currently approved physics.

[gothwalk.livejournal.com]

Oh yeah, definitely. I like my technobabble to be basically sound. But as with Fermi's paradox - which I can't kick far enough; nasty little anthropocentric piece-a-crap - I'm willing to throw things out if they don't suit.

[sciamachy.livejournal.com]

Hmm... I've been reading up on relativity and suchlike lately, and I can't see that FTL travel would be possible in the Star Trek type sense. On the other hand, you might have a kind of "fold the universe, and move instantly across the fold" type of FTL travel - relativity doesn't deny the possibility of that at least.

[gothwalk.livejournal.com]

Yeah... I'm just going to completely avoid the issues of how the FTL drive works.

Besides, relativity has a few flaws as a theory, istr - although I'm not well up enough on it to point them out.

[sciamachy.livejournal.com]

Oh, absolutely - the book I'm reading is "The Elegant Universe" by Brian Greene - it talks about relativity as a precursor (together with quantum physics) to talking about superstring and M-theory. I'm not sure, but I think that the speed of light limit still holds true though - the basis for that is that we have 4-dimensional velocity, which is a constant, the speed of light. If your velocity in the three spatial dimensions is 0, you're travelling at light speed in the 4th, time. This is why time slows down as you speed up spatially - the component of your velocity in the 4th dimension reduces in proportion to the increase in velocity in the spatial dimensions. So if you travel *at* light speed, time essentially stops dead from your point of view. Any more space velocity is impossible, since it's got to come from somewhere, and you've used up all the time velocity available to you.

The folded space theory allows you to travel at less than light speed, and pop up at a distant destination without having crossed the distance in between. It does have the disadvantage of requiring enormous amounts of energy though - think Event Horizon rather than Star Trek. Stargate SG1 comes close, but there'd be no intervening whoosh as you go through the wormhole - only the ends of the hole exist in space, and travel between gates would be instantaneous.

[ezrael.livejournal.com]

Keep in mind that all force is a product of geometry. So while your speed has to be constant within three dimensions, you can dilate which three dimensions that is and move vast distances within the three normally accessible physical dimensions we're accustomed to.

Also, if you choose, you can use the implicate order theory of David Bohm. Basically, the implicate order is a non-spacetime 'backstage' wherein all things are one and reality as we percieve it is introjected into being. So if you could enter the implicate order, you could essentially immediately travel to any place in space instantly without folding space at all or travelling at light speed, just by controlling where in space-time you're introjected back out. (Technically, this would allow for time travel as well, but you're free to simply ignore that as being beyond our understanding.) Implicate order theory makes an excellent 'hyperspace' but one controllable by real math...you can limit how far FTL travel works and how large or small the ships could be by simply saying that the mathematics of calculating entry and exit from the IO are so vast that only X distance can be calculated effectively.

[two-star.livejournal.com]

I note a small possible contradiction: it's cheaper to build large ships than multiple small ships, and communication is by FTL pods, which are essentially, (if I understand correctly,) lots of small ships. Why not just let all of the communication be carried by the ships? It makes communication more chancey, but for this Universe, communication being chancey seems reasonable anyway.

[ezrael.livejournal.com]

Definitely a good point. I'd suggest having the FTL pods (if you decide to keep them) be a holdover technology: basically, at some point someone created masses of these things, perhaps when the FTL problem was first solved, and they've been adapted since to serve as the backbone of a Pony Express type system.

Furthermore, if you were really interested in making for an interesting quirk of the setting to explore, maybe they're piloted. In fact, it might be interesting for the setting (especially if you're considering going in a more space operatic direction) to indicate that you can't go FTL without a living mind involved in the process...perhaps those 20 billion neural connections are the most effective system for doing the Implicate math, or perhaps FTL is psionic in some fashion...so there are actually crazy bastards who volunteer to be wired into a coffin-sized spacecraft and shot through space to deliver messages between colonies.

[ezrael.livejournal.com]

Some suggestions for how to deal with the Fermi paradox:

Some aliens are going to have wildly different technologies than humans do. One thing to consider in the technological development of Earth is how fortunate we are in terms of the material composition of the planet. Earth was generated in the wake of several supernova explosions, it's generally thought: we're an element rich planet in an element rich system for that reason, since supernovas tend to spray heavier elements (created by staggered stages of fusion...all the hydrogen in a star becomes helium, and then under gravitational pressure all the helium becomes oxygen, becomes silicon, becomes carbon, becomes iron, etc etc) when they explode. In other words, as rare as gold, silver and platinum are, they're a lot rarer outside of systems like Earth, which were fortunate enough to be created with a lot more of them than the universal average. Same goes for iron and other metals. So an alien species might well be forced to develop an entirely alien form of technology (and be a lot slower about it) just because it would have no access to any materials above carbon. (Of course, there are other worlds that were generated by supernova explosions, so those materials would exist, they'd just usually be rarer than on Earth.)

Biotech comes to mind, but there could well be all sorts of others that aren't occurring to me right now...a planet may have a natural crystal that forms via the interaction between its sulfuric oceans and its high-silicon crust, in effect creating superconductors via erosion and leading to a society that develops powerful magnetic resonance technologies before fire, as just one example. They might not have any interest in anything as crude as radio signals, but live in a shamanic hunter-gatherer culture (or even a hexarchical communal structure based on the transmission of spinal fluid, or weirder, since they are aliens after all): they don't talk to us because it never occurs to them to try and decode radio signals any more than the average person tried to decipher the hidden meaning in smells.

[two-star.livejournal.com]

I think that for some reason related to the drive, it's easier to build one two-million ton ship than two one-million ton ships.

The more I think about this the more I like it. There's real potential for coöperation and conflict here. Different colonies and groups within colonies would be forced by the economics to coöperate in building and running a ship. Even alien races could be drawn in. Suppose there are aliens that occupy different ecological niches¹, (like Europa type moons, or gas giants, or whatever.) It would make sense for humans to work with them, (either by renting space on their ships or by building ships as joint ventures.) Travel this way would be cheaper, but the aliens would have a say in where the ship goes, and their conflicts become problems the humans have to deal with when they're sharing a ship.

Really large ships might develop cultural identities of their own that subsume loyalties to species or to intra-species cultural groups. Of course, you wouldn't see too many of these in a galactic backwater such as ours, but when you do, it might make for an interesting story.

¹I'm assuming the ones that occupy the similar ecological niches to Earth would be less likely to want to coöperate.