Radiators

>not firing FTL projectiles from the other side of solar system at any enemy
>not firing bigger FTL projectiles straight into the target system's sun from several light hours away

FTL = Time Travel

Time and distance are a lot more connected than you might think.

Would throwing waste energy into your artificial black hole work?

That's because most of the losses happen inside the star itself. An artificial fusion reactor doesn't have the same problems.

Depends on how the FTL works. If you're accelerating past c, then yeah, time travel. If you're bending space with warp drive(to avoid violating special relativity) or using wormholes or some shit like that, then probably not. There might be some minor violations in the apparent causality of things, but nothing that would allow you to actually travel back in time.

Explain your reasoning, please.

Remember: If your setting doesn't have Dyson Spheres as your main habitat before FTL, it is an unrealistic setting and bad setting with no sense of scale or time.

See Carnot limit.

In my setting FTL is literally magic, so it's super simple compared to building Dyson spheres.

η=(T1-T2)/T1

>T1 = 170,000,000
>T2 = 400
>η = 0.999997

Always remember, thought, that a real Dyson Sphere would be a swarm of satellites and orbiting habitats rather than a solid shell. Also you can employ starlifting, sucking excess hidrogen from the star, for much more efficient energy production and longevity.

But user, if the Pathfinder doesn't found colonies down a bunch of inhospitable gravity wells, our people inside a perfectly serviceable space station with artificial gravity and ecosystems will never survive!

transhumanism renders a lot of this obsolete

>implying their are actually people in the space ships
>implying the space ships aren't the people

What are your radiators going to radiate with? You need a medium to transfer heat, unless they are more like sinks and simply build it up until they can be transferred to something else or dumped and replaced.

Real astronaut suits and space stations control interior temperature with heat-exchangers, put brutally simply, they are constantly keeping one side cool and one side warm, not absorbing and dumping heat somewhere else, or into space somehow.

>implying transhuman virtual people even bothered going into space after they found a nearly 100% efficient source of energy and created a perfect virtual reality where time nor material distance mean much.

>You need a medium to transfer heat

No you don't.

>Conduction
>Convection
>Radiation

Having a medium is the most efficient way. But in the deep space, you can only get rid of wasted heat by radiation.

>You need a medium to transfer heat
Did you grow up in a cave? Have you never felt the warmth of sun on your face?

I watch Isaac as well fellow user.

I would assume that if your FTL works by accessing some sort of subspace you can configure some sort of system to dump the heat into said subspace avoiding the need for large external radiators.

>When I was on the ISV Venture Star I wanted to eat manicotti
>I compromised. I ate grilled soylent off the radiator
>I wanted to fuck a woman
>I compromised. I jerked off into the matter-antimatter engine

>tfw no spaceship gf

Just going by statistics and probability there would always be an outsider willing to do such a thing unless physically restrained by everyone else.

>thinking you can reliably track let alone hit targets over such distances

i found that by far the weirdest concept in eclipse phase was the idea that i could potentially play a spaceship as my character
honestly, there was nothing else quite as jarring to me as that.

>reversing entropy
Yeah, no.
What do they teach you at schools?

You can reverse local entropy while increasing total entropy in the universe, user.

Why is that jarring, user? It's a perfectly natural step in AI, to give them ships to drive. Then why is it so different to make digitized humans the pilot?

if you have ftl sensors and enough processing power...

fucking laughed really loud user.

>FTL
>violate causality
>infinite energy and matter
>violates thermodynamics

Yep.

>ever bothering to build a sphere
A swarm sure, but you just need enough power generation power some kugelblitz and use those for power generation, feeding matter into them as needed. Then just build some space habitats near your kugelblitz, don't bother trying to build a sphere around your star, doing so would be pointless and a pain in the ass.

Only the first one is true and it doesn't have to be a problem.

Violating causality automatically enables free energy user.

1. you have 2 energy
2. you spend 1 energy unit to go back in time to step 1.
3. you have 3 energy. you spend 1 energy to go back, now you have 4 energy...
4. copy-paste as long as you need because it takes 0 time to do the loop.

Hiw FTL violates causality though? You just arrive a bit earlier than the light of your rocket engines, but that's not time travel.

Yes, you know how? By producing more energy. That you need to vent somewhere after that.
You can't heat your bullets to temperature higher than the background temperature. Unless you mean you want to dump them through the reactor and then fire them once they get hot. Well, I guess this could work.
But if you want to vent this way, say, 20 kWh (energy produced in a central heating of an average house in an hour) you need about 10 kg of almost molten iron. Now, for an engine of an oil tanker it's 300 000 tonnes of molten iron. About 5 000 tonnes an hour (100 000 hp, 50% efficiency).
I don't know where you intend to store it.

Correction, 5000 tonnes a minute, 300 000 an hour

Radiators add options magic heatsinks don't.

Imagine you meet another ship in orbit:
>keep radiators extended as sign of peace
>keep radiators extended for maximizing rate of laser fire at risk of getting shot off
>retract radiators behind armor shutters to maximize short-term survivability at cost of more heat long-term
>giant energy-weapon-cooling radiators vs lower-heat shorter-range kinetics
>emergency life support radiators

They're like sails in a piratical setting.

It is. You're thinking in Newtonian mechanics, which is not how the universe works. In relativity, the speed of light in a vacuum isn't just the speed of light, it's the speed of information.

Going faster - no matter how the actual mechanics work - is outrunning information. It's like a computer process being pulled out of the registry and re-inserted at a different spot on the timeline.

Think of each lightcone as its own universe. By leaving it, you're cloning yourself into a new universe at a new point on the timeline.

>Unless you mean you want to dump them through the reactor and then fire them once they get ho
This is what the user was talking about to begin with.
>I don't know where you intend to store it.
Space age nanomaterials.

So how traveling at light speed makes my computer calculate faster? I don't understand it.

If we're doing hardish scifi would huge ships need fucking massive radiators like on the ISS or what?

I want to have heat as part of my dieselpunk world for the spaceships, maybe the ships have radiators on the hull but can extend large ones to get rid of heat quickly etc, but for very large ships, carriers and w/e the radiator panels would need to be giant.

What cooling systems could you have? Liquid nitrogen?

So what are these things on the ISS labeled Radiators smart guy.

My ideal posthuman existance is as a spaceship drifting srome start to star soaking up data on the universe.

We're talking about alcubierre/wormhole "cheat" FTL, right? Just so we aren't dealing with the additional problems of trying to conventionally accelerate past c.

Surely if such a method of travel is possible, then c isn't the speed of information?
I'm really failing to see how you could practically violate causality with something like Traveller's J-Drive

Imagine a curve on a graph, with space on one axis and time on the other. That's a universe. You can be at any point on the curve - it's like a bandwidth cap, that trades off between the two values. Go really far in space and you'll go a little slower in time, and vice versa. That's time dilation.

If you stay on the curve (representing the properties of a relativistic universe) yet somehow circle around off the positive/positive quadrant to get a bigger value for space than c permits, then you have to have a negative value for time to add the two up to meet the bandwidth cap.

this gives a nice limit for ship size. heat generation is proportional to mass, which is proportional to volume, but surface is only increases with square, not cube. after a point there is no way to transfer heat fast enough and building the radiators would get to ridiculous proportions. like it.

to answer your question: yes. you need to radiate away all the waste heat, meaning all the heat that you didn't turn into movement (for you or your projectile, be it hunks of iron or photons) in a primitive setting where matter generation and other bullshit doesn't play.

Yeah but time just passes faster or slower to you, it's not time travel where you can go back before you started your travel? You go just in one direction not loop around.

The smart way to do it is with a magnetic droplet radiator: spray molten iron directly into space, then use a powerful magnet to pull it back once the droplets cool down enough to solidify. It's lighter, harder to damage, and makes your ship look like kind of some giant robot phoenix when it's running.

Conventionally accelerating past c is physically impossible. It takes exponentially more energy until you hit that limit, which would require infinite energy.

Visser radiation and directed acyclic graphs are a good-enough handwave for wormholes. They don't make the problem go away though - they create an artificial universal reference frame ("empire time") for the wormhole network.

A go-faster drive that takes a few weeks can violate causality like this:
1. take off from planet A in 2017 local time
2. arrive at planet B in A2017, B2013
3. fly back to planet A at B2013/A2009

The big discovery of relativity was that the speed of C is the same for everyone.

If you go faster, that means someone in a different place goes slower.

I can see where you're coming from, but surely you'd reach B2017 + 1 week-ish?
Now I'm not trying to imply a universal frame of reference, but a bigger(faster?) one.
If matter/energy/information from our universe can enter subspace/hyperspace/𝛕-space and return, then practically speaking wouldn't the speed of information in our universe be whatever the speed-of-light equivalent is in the FTL-universe?

Still doesn't work for warp drives though

My dick has near-relativistic speed and mass.

I hear wearing two condoms helps with premature ejaculation.

>railguns work with magnets
>heat disables magnets

Fucks sake I want space battleships.

Is it literally impossible to cool these huge ships some other way? Could we discover some sort of coolant that works really well?
That sounds interesting.

But you still can't go back to your past, right?

That's not how railguns work, they work with magnetism, not magnets.You can actually form the rails and projectile from plasma and they will work just fine.

Linear motors actually do work with molten metal. It's sometimes used in industrial processes.

I did fuck up there, what I tried to say had more to do with the molten metal that was mentioned.

Not electromagnets, friendo.

Yeah, but the magnitude thereof depends on how much heat the ship produces

>Not electromagnets, friendo.
I was talking about the fact that you can't use magnetism to fire molten metal at your enemies but worded it badly.

>ftl

>not using free energy to power your space drill ships through the cosmic glacier

Tust du even VRIL?

Doesnt Dark Energy violates thermodynamics? There are .any things that we dont know.

>if you have ftl sensors and enough processing power...

lol are you just pulling random words out of your ass? How would those sensors work? What king of input put those sensors read? What kind of information would your target give off that's ftl? There's very loose sci-FI and then there's nonsense. What you said is Lucas tier nonsense.

>What king of input put those sensors read?
Motherf... I meant "What kind of input would those sensors read?"

Of course you can. That's the simplest exploit, see . You can loop yourself/your ship until every cubic meter of the universe is filled with copies. Then you can power your ships by using their own clones as fuel, feed yourself with cannibalism by killing yourself from one second ago, have clone orgies, you name it.

you can bind energy in chemical processes. there are endoterm processes that take up energy, simplest would be melting ice or boiling water. that buffers heat somewhat, but sooner or later you have to release it. so battles have time limits, after a while your ship will simply cook if you don't extend the radiators, be it rigid structure or sprayed metal.

we talk about hitting targets from lighthours away. we are obviously past hard science fiction.

There's a difference between spitballing about ftl travel and talking about some kind of ftl sensor. Like what does that even mean? A light sensor sensors light. What does a ftl sensor sensor? It's just random tech words put together.

You need to achieve imaginary mass.

Inside a Black Hole, time and space switch positions. You will always end up in the singularity, but you can move throught any time in exchange of getting closer to the singularity.

Tachyon collapse.

Are you serious? Please explain to me how you convert tachyon collapse into a targeting solution for a fast-moving target that's a couple light hours away.

A tachyon with an electric charge would lose energy as Cherenkov radiation.

That didn't answer my question in any way. How do you use the properties of tachyons to determine a proper targeting solution for a target moving at ftl speed that's several light hours away?

>that feel when this qt3.14 Nazi sorceress is chilling in the Aldebaran system with the clone of Hitler while we argue about relativity
I guess we should all just get high as fuck, contact psychic aliens through meditation, and draw up space ship designs through automatic writing.

Who cares if nobody understands how it works?

Okay give me a concrete example so I can wrap my mind around this: you have a FTL capable space ship. How you use it to win the next week's lottery?

ok, lets come up with shit, with more or less plausibility.

the mentioned tachyons might be a solution for example. if we have all kinds of tachyons, with differing speeds over c, they represent different information from the future (as they travel backwards in time). their interaction with the future ship gives you an accurate position of them in the future.

you have higher dimensions above the spacetime, which are too small to travel through but can be used to sensor. in these, distance can be arbitrarily small or large between two points in spacetime.

above this it really gets into bullshittery.

I like radiators in my Sci-Fi, but you don't need them.

If you told one the ship minds of The Culture that their ship shouldn't work because of radiators, I'm sure they'd have their drone projection smile sweetly and say something trite about "fields"

1. wait one week, find out the winning numbers.
2. travel back in time, leave a note about the numbers
3. ????
4: PROFIT

since your travels, if you do it carefully won't affect the randomness which guides the numbers that come up, now you know which numbers will be drawn.

now I'm a really big fan of Banks's scifi (although Against a Dark Background is my favourite, it's just so mindfucking, the thousands of years of history, ruins, nuclear shit and what it generates, Earth might turn out very similar), it's really handwavy. It's hard from one aspect, namely that it is consistent with it's own handwaving, but the Culture is provably not living in a relativistic universe.

Quantum entaglement seems to do this. See the quantum eraser. The problem is that the information is encrypted, due the random nature of the particle-wave, until you send the message.

Banks does seem to be a big proponent of the "Sci-Fi as a lens on our own society" school. He clearly gets a hard-on over mega-structures, but I get the feeling he'd have thought excessive details get in the way of his stories. Something like the Hydrogen Sonata for instance, do you really need to know how field displacement works to take in a meandering discussion as to the nature of democracy and society. I love it.

Now radiators; they belong in the other big school of sci-fi... I don't know what I'd call it, maybe the Arthur C Clarke school of "here's some crazy shit, what would it do to us as a species"?

In my head I always compare him to Frank Herbert. Both of them concerned themselves more with the social effects of tech than the actual tech. Although Herbert wrote more esoteric stuff, which simply means his established tech level didn't justify the jumbo that happens, unlike Banks whose tech level is so high it is literally magic, which justifies almost anything. As long as you are consistent with it. If not, you get space fantasy, which is not my genre.

Love to compare it with other high tech settings, like the Xeelee for example. Baxter is a scientist, that shows, he knows his shit somewhat, but he is really bad at imagining how a society would work with that history and technology. Also he makes ridiculous faults that an elementary student would figure out it's bullshit, but his big picture physics seems to check out.

>the answer is always 'draw the rest of the fucking owl'-tier
this is why you ftl time travel fags are considered memers and idiots

Maybe I'll just have the ships release heat after battle but have the heat transfer be faster so giant radiators are not needed constantly.

With an Alcubierre drive, chart a course in spacetime that results in negative time displacement (which, with FTL, is every direction in space) - fly into orbit, fly in circles, zigzags, and lines, until you have traversed enough distance that the negative time matches up to how far back you want to go.

With a teleporter, you simply teleport directly into the past. This is a bit tautologous, but all coordinates in spacetime are spacetime coordinates because spacetime is one entity, not two. Plug the desired spacetime address into your Battlestar Galactica drive and teleport to the year before the Cylons revolt.

it was already explained to you if you travel over c (in reference to Earth), you effectively travel back in time and arrive back on a previous Earth.

Guh. I remember that faggot who kept refuting his own version of RT whenever someone else tried to explain to him how the real RT works.

Not read any Baxter aside from the ones he wrote with Pratchett; worth a look? I personally wasn't blown away by the "The Long Earth" stuff.

Bating controversy; I love the first Dune book, its super imaginative, truly epic... however its second place behind "Ringworld" for me in terms of horribly outdated and highly questionable personnel politics.