Spaceships and Science fiction

GTOM

Yes, we became pretty OFF.

Ok, I understand what you say.
I read atomic rockets, pretty much ruining even the books of Heinlein. :((

I guess this Ender is a fine character, but i would still like the read or write about different kind of battles and characters... now i dont see much options to do that without every kind if purely fictional hyperspace based device.
Or leave out entirely the war scenario.

Ryan_m_b

I would recommend the Dread Empire Fall trilogy. It's not very well known and it's a bit soft-SF but it has some of the best and most realistic descriptions of space tactics I know of e.g.

• What kind of evasive manoeuvres ships should do to avoid getting hit whilst staying close enough to offer each other covering fire but not too close so as to take each other out if they are hit (as they use antimatter for propulsion ships go out with a bang when critically struck)
• How to fight over light hours of space
• How to use gravity wells and planets to your advantage
• Techniques for managing the crew under high-g

On top of that there it covers how to lead a resistance in a very centralised (all comms monitored, everyone on a biometric database) and totalitarian regime.

EDIT: Now that I think of it DEF does have a somewhat convincing use for a fighter-type craft. Basically when they are fighting over long distances (light minutes-hours) they send out small one man ships called pinnaces along with a swarm of missiles. The job of the pinnace pilot is to give last minute tactical orders to the missiles depending on the situation at the time.

PrepperMike

read Ian Douglas.

GTOM

In other threads, we had a consensus, that fighters and corvettes are "brown water navy", operating on orbit, and big shafts of moons and asteroids.

Otherwise, I 've also thought about beam empowered fighters and small missile control ships.

I see that trilogy ruled out AIs.

PrepperMike

Ian uses AIs for high speed stuff that human reaction times can't handle, but other stuff he feels is best done by humans. His biggest argument against AI is do you want control of high powered weapons with an AI or a human?

Ryan_m_b

That's a meaningless question unless you provide a detailed description of the characteristics and capabilities of the proposed AI.

SHISHKABOB

a good way to force action sequences or whatever is to make up magical- er I mean fictional chemicals or elements that have some oddly specific behaviors. For example, in the anime series Legend of the Galactic Heroes, there was some funky gas stuff that exploded very violently if lasers or guns were shot through it. Sort of like the laser vs. shields thing in the Dune universe. This forced armies to duke it out in fancy armor, crossbows and giant battleaxes. The rest of the show was about giant space battles where the ships lined up like 18th century European line infantry and space politics.

But they got to add in some really cool face to face melee combat scenes because of some magical gas that they made up.

Ryan_m_b

That's the cool thing about speculative fiction. You propose some sort of technobabble and explore the societal and practical ramifications. For instance, if this gas explodes violently then can it not also be harvested as a powerful fuel? Simply store it in gas canisters and spray little bits at a time into a laser lit engine. Or store it at very high concentration and then light a laser inside the canister as a bomb.

GTOM

Yes I watched Legend of Galactic Heroes, i dont know if they used the Zephyr (I think) for propulsion purposes as well.
(Otherwise I disliked that series, Yang always knew what the enemy is planning, they launch a small attack, Send there our whole navy! Yeah why not, next time, they launch a very big attack, and of course it is only a decoy...)

Basically, in deep space, where arent civilans and neutral parties, AIs cant do much wrong...
In case of orbital patrol, human decision is needed, and i doubt that remote control is always enough, there can be spys for example, that can hack the system to create an international scandal or something like that.
Also you have more options to rescue pilots.



I had the idea, that aliens can deploy self-replicating nanobots to Earth, to infect computers, turn our own robots and infrastructure against us...
They want everything to be ready, by the time they arrive.

However, if their plan A fails, they can launch a relativistic torpedo against Earth...
Is it possible to counter, without hyperspace senses or thing like that?
(It is so magical, one could even bring the Force to the image)

Although... if humans can learn the whereabouts of the alien homeworld, they can also threat them with R-torpedos.

Ryan_m_b

Without magic technobabble like a forcefield not really. The most you could do is fill your system with highly sophisticated gravity sensors to sense the RKV as it comes. You might not have much time at all because if it is travelling at 0.9c (which btw is roughly the velocity an object needs to reach for its kinetic energy to reach half its rest mass) and you detect it at one light day out this means it is only two light hours away. If you do have time you could try to divert its path with powerful lasers or try to through mass in the way to deflect it but I doubt you could really do any of that.

Charles Stross dealt with this issue in his novel Iron Sunrise. In it various factions have STL-deterrents hidden in their Oort cloud operating under a dead-man switch. If they don't receive a signal every X hours they launch towards a target planet (trying to find a tiny ship, possibly stealthed from across a system would be next to impossible). This largely stopped factions invading each other for fear of severe retaliation years later.

GTOM

If a RKV hits a one kilogram mass before the planet, what would happen to it?
The energy of the collision could turn it into a dissolving plasma cloud or dont?

Ryan_m_b

At around 0.87c the kinetic energy of an object exceeds half it's rest mass. So a one kilogram RKV travelling at 0.87c relative to the planet will have the kinetic energy of e=0.5*c² = 4.5 petajoules = ~10 megatonnes of TNT (~600 Hiroshima bombs). At that speed it would get through the atmosphere in less than a millisecond and cause massive devastation to the area it hit (akin to a nuclear explosion plus an earthquake). Some quick googling tells me that the meteorite that killed the dinosaurs released ~0.5 Yottajoules of energy which would be the equivalent of a 5 kilotonne RKV travelling at 0.87 which works out to be roughly the mass of 50m x 10m x 10m of ice.

This is something that a lot of SF authors forget in their haste to write about relativistic ships the size of super-carriers and cities. The very ships you have littered in your setting as though they were sprinkles on a cake could all be converted to weapons thousands of times more powerful than the meteorite that caused the K-T mass extinction! (this is also known as Jon's law or the Kzinti lesson)

GTOM

I can see, but if you try to put a brick in the way of the RKV well before it hits the planet?
Would that mean, that only the brick disintegrates in the collision, or the RKV also?

Ryan_m_b

Whatever you put in front of an object travelling that fast would just be disintegrated, like a wet tissue paper thrown in front of an artillery shell. It may slow the RKV down a negligible amount but what you really hope or is to divert its course ever so slightly so that it misses its target. More likely though is that it may cause the RKV to break up but even if it did it wouldn't change the amount of energy that is about to hit: whether it hits the planet in 1 piece or 1 million pieces the same horrendous amount of energy is about to be released.

SHISHKABOB

my problem with relativistic weapons is how the heck do you aim them properly

Ryan_m_b

What do you mean? Why would it be a problem to just aim, accelerate it up to a high fraction of C and watch the fire works? If long distance is a problem add some form of sensor and some thrusters to tweak the course. Even a small fraction of a degree course change could have big consequences after light hours-years

SHISHKABOB

this may be a misunderstanding on my part, but wouldn't it take a looot of energy to change the course of something moving extremely fast?