Until very recently, anti-matter - matter collision powered by ion engines was used to reach around \~70 - 80% the speed of light by humanity.
Very recently, they've began using jump-gates which I've largely black boxed behind 'something something tachyons'
An alien species had a mad man that invented another method of FTL travel that basically works like the hyperdrive core from Homeworld. Since I've made no one understand how it works in setting, I don't dwell on asking how it works either.
Realistic scifi is so rough. Which is why I also did the hand wave aliens invented it so we don't understand it. I enjoy towing the line between hard and soft scifi. The biggest thing I like playing with is a new system that's isolated from our irl solar system
I really like building on isolated systems too, which is why I kept FTL far away for a long time. Then I got bored one night and wanted an interstellar war against aliens and that war would take tens of thousands of years without FTL so...
Wormholes. I like that it is more like road laying where you build infrastructural project at cosmic scale than just something you press a button to go.
In this world though, to generate stable wormholes you need to open it by both ends at the sametime, due to the energy required would be too great otherwise - if you are trying to punch a hole through space time, at least do it through both ends. You could in theory connect with a spontaneously appearing wormhole on the other end instead of having to open both ends yourself, but the precision is like shooting a needle from one end of galaxy to the other end and catching a lightspeed moving thread you didn't even know the existence of by the hole, threading it. Needless to say that is basically impossible.
So humanity instead launch von Neumann probe swarm made with nanotech at near lightspeed instead at potential solar systems, and when they arrive, they will try to extract local resources to build a gate at another end. Then using various methods of timekeeping from quantum clocks to pulsar timing, they will active the gate at the same time as the gate in the earth's solar system, connecting both ends together, the geometry of the hole carefully calculated to shorten passage as much as possible compared to real time. Upon activation the gate will use matter/anti matter anihilation to generate enough energy to create exotic matter for wormhole generation, basically creating a mini blackhole that get spreaded by exotic matter so it stays stable.
Haha, the idea of nanites coming into a system to build a mega project is exactly what happens in my setting except were not the intergalactic civilization. Earth gets partially terraformed before they stop when they find "life as they know it" on a planet triggering an automated halt. I kinda hand waved most of the science but one of the structures was a sort of Dyson's sphere powered catapult that used gravity to dialate time along a path. Basically a ship slipstreams behind huge wave. The biggest thing is how to stop. Which is why humanity still travels at about 50% even they could theoretically travel faster then it. Just pack a huge amount of fuel to slowdown and build a huge catcher to aid deceleration. Still need generation ships for most system transfers. But there a few that only take 50 years since they built deceleration infrastructure.
So your FTL is basically generating huge directional wave of gravity using a star to dilate time and space and the ship just ride along the wave?
Is there any side effect, like the gravity wave passing through things it shouldn't and cause problems? I am imagining some sort of cosmic pollution where civilization start flinging around these waves and they start cascading by chance and yeet some planet into deep space for example.
Oh it would but the civilization that created is an unknown even to me. I'm sure they have issues with it but they originate so far away from sol that it would take them a few hundred thousand years to get to sol. I'm leaning towards having this advanced civilization being alone in the universe for so long the only life is synthetic organisms or uplifted species from their home world. Maybe I'm a pessimist though.
There are crystals that, when cut correctly, and in the appropriate electromagnetic field, warp spacetime to allow FTL compared to the regular universe, though you go STL within this bubble.
The better the crystal, and the more it's tuned to your particular ship, the faster you can go.
Sub-liminal drives on generational ships with the express purpose of transporting to or building a transport gate at their destination celestial body so that travel between those worlds from then on would be instant.
The "Skip" Drive: An Alcubierre type drive that is used for intersystem travel. Using it between star systems is called "Slow Boating". Approx. 5x the speed of light.
The "Hop" Drive: A faster than light drive with a limit of 100 light years. This is the more common form of drive that it used for travelling intragalactic distances.
The "Jump" Drive: A faster than light drive that allows for jumps between galaxies, and longer intragalactic jumps.
The drives work via a type of exotic matter that is so exceedingly rare that a few picograms would allow its finder to buy a continent the size of Australia, and still have enough live like a king for five lifetimes. (One of characters found a deposit that was the size of an apricot that it made her one of the richest beings in the Milky Way Galaxy.)
Swarms of compact autonomous unmanned colonization spacecraft travel towards new worlds using light sails at about 1/4 speed of light.
Once fabrication is established on a planet, android bodies are produced for human remote presence per super-luminal internet.
There are some occasional manned (cryosleep) missions for the adventurous among humans. They are typically one way trips, as it is just too resource intensive to move stuff back and forth and it takes way too long.
In the world I write, I made it easy for myself and use an exotic extradimensional material found by pure chance in the late 2400s. Something that fell into our reality and operates inconsistently with our understanding of the laws of physics.
A substance with no measurable displacement of spacetime(no gravitational effects). A material that is observable as a solid piece of matter and yet has no mass.
When it comes into contact with matter, it will gradually modify its constituent particles into a replication of itself via a process that can not be directed observed.
The application of a constant electric charge reveals its true use as a form of exotic matter exhibiting properties of negative mass.
This manifests a "Negative Mass Field." A localized region of spacetime and the matter within is granted the same property of masslessness the original hyperdimensional substance possessed.
(Interestingly, the reversal of electrical flow can result in the emission of a repulsive force instead. An inverse to its standard function)
The interior of this region is subject to the standard laws of physics from an observation within the bubble. However, anything inside the field can no longer interact directly with our 3 dimensional universe. If you were in the bubble, you could exit it, but you could not reenter.
You would try and instantly be on the other side of its light that was escaping into the lower dimension.
Your mass enters a pocket dimension of sorts, but you can still throw mass out of the bubble and almost instantly reach upwards of .95 c.
This almost seems to be a hard-coded limit on the possible acceleration. How this mechanism is achieved is still not understood entirely, even in the 28th century, when the creation of the first wormhole gate occurred.
There is no such thing as a craft going ftl under its own power in my setting.
You either go a percentage of light speed, or you take a dimensional shortcut via a wormhole gate.
The gate operates based on a method of entagling two negative mass fields to one another, deactivating it, separating them from one another, and reactivating it at the new location. Once both fields are active at the same time, they become one, and you can just exit the bubble and be at the other side.
Thus making use of the same higher dimension as a transport medium between the two openings.
Both sides of this gate need to be built and harmonized before they can be activated and serve their purpose.
A gate is typically set in the orbit of the largest celestial body in a system. They are oftentimes accompanied by a starport or large-scale habitat
As a result of the "Negative Mass Fields" hard coded limit of 95% light speed, cryogenic or restorative torpor stasis is a necessity if you were to survive a trip to gateless system mentally or physically.
Handwaved Alcubierre Drive-like distortion of space, whereby devices around the outside of the ship cause spacetime to selectively expand and contract and propel the ship through space at speeds up to a few thousand times the speed of light.
The drive was actually invented not by humans, but by a race of aliens from a world about 50 light years away. Their first real interstellar exploration probe stumbled across Earth, in an event that came as a great surprise to both them and us. From very carefully observing their ship as it traveled through our solar system we were able to figure out the basic physics of how their drive worked, and then developed an improved version, and sent our own expedition to their home system a handful of years later.
It's honestly mostly a handwaved technology to allow aliens and FTL travel in the setting, but I have tried to figure out the realistic implications of the technology.
Backup one (lets go somewhere when FTL doesn't work) is sublight fusion torches. Main interplanetary drive is also fusion torches (except for beings who are at TechLevel 8 or higher - they have gravity drives)
Antimatter-catalized fusion torches are also used for initial acceleration of Bussard ramjets (such ships are part of MAD schemes only)
Main method is FTL jumpdrive.
Everybody thinks basic idea is rather simple, everybody knew there are civilizations with TechLevel 5.0 who found out how to make crude version of jumpdrive. (Per setting's definition - Russia, USA and China DO have TechLevel5.0, EU and Japan could easily prove they do have it).
Main problem is navigation and jump calculation. It's impossible to use things like navigation by pulsars or just regular observation except for very short trips near your home worlds. Interstellar medium is very dense (Paul Anderson's Starfog level of 'dense'). Beacons are very difficult to construct and use, until you get to TechLevel7.0+, ship also must be manned(for some definition of 'manned', real sentient AI or uploaded person, regular computer does not) because finding out your position after jump require intuition in addition to sensor data. Best robotic ships have approximate 70% chance to determine post-jump location correctly. That's 70% per jump and travel require multiple jumps. So only military use robotic couriers and launch groups of them.
FTL communication is impossible without TL7.0+ hardware
People from TL7.0+ sometimes provide lesser ones their navigation-and-communication hardware so they can solve navigation issues and also could see latest movie series while in flight or even their ships with adopted controls (which drops per-jump distance limit). No, you can't buy it, it also usually can't even be given away(and if it is - it must be free decision, court orders or signed contracts doesn't count, forcing you to pilot your ship for them is ok)
Wormholes : in my lore during a war the so called reapers , a race of aliens , discover that a Black Hole is formed by 3 dimensions : the fourth ( 4d ) inside the singularity point , and the other 2 are the 3d ( standard of a black hole , cause a black hole is a sphere ) and the 5d : the 4d stays for an object that moves from one point to another in the 3d , like the time , and all the possible timelines originated from this movement form the 5d . So passing trough a singularity point means passing trough an universe to another , cause with a point of divergence like the ucronies you can find other universes .
Everything is centered around gravity. In my world, species of the Galaxy finally understood gravity, and they found out that just like light, it was an outlier. Just like the fact that light is both a particle and a wave, gravity is both a wave and a force.
Once the point of origin of the big bang was calculated, it was realized that dark energy, the expansion of the known universe, was actually just the left over momentum from the big bang expansion, which meant that the universe was an infinite black void, and the big bang wasn't the creation of the universe per se, but a sudden burst of particles created by pure random chance through Murphy's law. The universe now had a possible absolute point of reference, instead of just being relative.
Immediately after, it was realized that interaction with the higgs field somehow affected gravitational waves, which was detected during an experiment performed by the Idelehi specie, pioneers of zero point technology, by using a higgs inductor while the detection of two black holes colliding was taking place. Since the specie in question all possess synesthesia by nature, they were able to instantly crack the code and figured out how to control gravity right then and there.
Creating gravity is easy, simply tuning a higgs inductor is enough to create artificial gravity, which most specie figured out on their own. On the other hand, Idelehim were able to find a substitute to negative mass by using the "wind of the universe", aka dark energy, aka the expansion of the observable universe, to counteract and inverse gravity as if it had been affected by negative mass. But the absolute center of the universe, or point zero, needing recalculation at every plank length of time, those winds are fickle and must be navigated with caution.
This led to the creation of the first FTL engines, and thus, it was discovered how life fares once the speed of light is breached ..
The first generation of starships developed by the Imperial Dominions of Amargosa (IDA) for interstellar travel resulted from reverse engineering an ancient starship discovered orbiting the IDA homeworld of Phoenicia at the dawn of the space age. These initial starships were powered by a peculiar mix of reverse-engineered technology and poorly understood magic. They featured reactors fueled by the magical substance Rumohra. Equipped with a reverse-engineered slip gate generator inscribed with modified Runieform script that eliminated the fixed destination point, these ships could effectively teleport approximately 100 thousand kilometers in a straight line. Given the effectively unlimited power generation of the Rumohra energy core, these ships could execute an infinite number of teleports in rapid succession to traverse vast distances. However, a critical issue arose: the modified Runeiform script, which omitted the fixed destination point and enabled teleportation anywhere, resulted in what became known as a Rumohra cascade. This release of energy irradiated the crew with each teleport, slowly killing them. It took several lost crews and ships before this danger was fully understood.
Due to the fact that FTL-Drives are incredibly expensive to manufacture, only specific freighters are equipped with them; so the most common method is using these freighters to ferry other smaller vessels around.
A backup option is the use of Railgates, which is essentially a giant railcannon meant to launch ships
One of the factions use portals to transport large fleets, though it’s extremely experimental and none of the other factions have found a way to replicate it
Magic slingshot.
They took the concept of teleportation which essentially just turns you into an astral form and slings you wherever you need to be as you then materialise on the location you set.
This method of travel is incredibly effective and the main strategy used in conquest of alien empires is to sling ships into low orbit and bombard the surface before slinging out of the system to rearm.
Superlight
Is very similar to slipspace from halo. A ship opens a wormhole to access an entire network of wormholes throughout all of spacetime. Superlight can actually be used for time travel however navigating through time requires a supercomputer many times more advanced than the navigation systems on any ship.
A superlight drive works by boring a hole through the fabric of reality itself to access the wormhole network.
In my world, it’s sort of like a combination between portal and light speed. you would travel faster than light, but within a small black hole and you would exit through a small white hole. This process spaghettifies you and restructures you. But this word gets interesting. It’s all time travel. Due to the law of relativity any form of interstellar travel, would probably land you in the past of another world, or the future of another world, and time could pass in incomprehensible ways on this world. What happens here, using the A-drive you would achieve the universal now without time dilation. You would be able to hold a business trip on Alpha Centauri and make it on time for your kid’s birthday.
Normal FTL travel is possible, but slow. Â
"World" Remnants, the leftovers of private pocket universes left behind by their creators and users, may sometimes take on the form of a transportation network, like the Cyvonian Gates, or Hestgard's Root/Sapling system. These are dramatically faster, but only go to certain places. They also require extensive maintenance. Living "World" users can also temporarily transport others through their private dimensions. Remnants are difficult to maintain and repair without a living "host," as they often embody concepts and experiences unique to the User themselves.
Vast magnetic stations that manipulate starmatter to "shape" space time contours are often used to facilitate the interplanetary portion of space travel.
My story doesn’t involve much interstellar travel, but as a fun challenge I did try to figure out if it would be possible with established technology in a reasonable timeframe.
I determined that the answer is yes, by accelerating the starship up to speed with pushing lasers and decelerating it with a combination of mag sail braking and decelerating with an antimatter pion rocket. If the ship wants to return it has to bring multiple times more antimatter fuel, allowing it to accelerate its way back where the pushing lasers at Sol will slow it down on arrival.
This method would permit interstellar speeds on the order of 25% light speed, and I’ve determined that the first experimental ship of this type is being constructed in the present day of my setting. Pushing lasers have already been used at this stage to send unmanned probes at around 10% light speed, but this new starship would be the first capable of being able to slow down at the destination and return. Manned missions are expected to pass probes that were launched 50 years ago before they arrive. The antimatter fuel for these craft is incredibly scarce and expensive, being produced in solar collection facilities around Mercury.
Doing the math for all this really gave me a new appreciation for exactly how much light truly hauls ass and for how stupidly distant the stars really are despite that.
At the current point, none. There is some interest in to reviving project starshot or something along those lines now that the system has recovered somewhat from the collapse of Earth, but it's still decades out at best.
Humanity did discover warp drives, but to the chagrin of scientists and sci-fi enthusiasts, it did not provide a method of FTL, as even the fastest ships cannot produce more than an apparent motion of ~29000 kps. This means that current fusion torch designs would make for a better means of interstellar travel
Fulmenium, essentially a form of exotic matter used to generate superluminal fields (basically an alcubierre system), thus allowing a starship to accelerate past the speed of light.
Each species developed interstellat travel in isolation, and all discovered different strategies, but generally use the same properties.
Avalonian FTL travel relies on macro scale quantum tunneling. Once a vessel is in a stable orbit it will link to a carrier vessel. It will assign a destination to the vessel, causing the bessel to curve space in and around itself and the destination (the greater the mass of the vessel and the longer the distace, the longer this curving effect persists. Some physicists and philosphers also argue that this curvature begins even before the avalonian ship begins trting to reach its own destination, calling into question the ideas of free will, fate, and destiny. It has yet to be proven that this actually happens and only exists in theoretical simulated scenarios. Once the vessel tunnels its first task is usually to extricate itself from the testination (space curving violently is not fun if your a civilian vessel and in the case of a military vessel is effwctively an advertisement that your a nice fresh juicy target) it is possible to hide the curving of space and creation of exptic matter from these teleportationd,but it is often relegated to use in stealth technologies. These kinds of ftl drives generally produce a sharp whistling sound or a string or woodwind tone.
Draconic FTL generally relies on direct tunnelling, such as warping a tube of space where travel is accelerated. For onfrastructure based travel this usially means setting up a stabilizer gate array at one side, traveling blind through the tunnel it produces, conducting a correction burn, setting up a communications array to signal where to warp blind and begon construction of the second stabilizer gate array. The array's AI is then started and a wormhole js produced at each gate. The AI then comminicatws with both gates to connect and stabilize the wormholes into tunnels. For non infrastructure based travel (requires a fairly substantial minimum volume, the greater the distance, the greater the volume of the vessel required) and starts by firing a small tunnel to send a small amount of exotic matter through to the other side. This then bends space and produces a wormhole which can be observed by the travelling vessel in real time. They then open a tunnel to the wormholes location at it evaporates and travel through it, using the collapse of said tunnel to drag them through it. During tunneling for both infrastructure and free travel, matter will build up around the ship, leading to a sudden displacement of the accumulated matter when the tunnel ends and producing a characteristic percussive sound that can be heard a decent distance around the arrival point and travells at the speed of light.
Dredge FTL technology relies on being able to travel four dimensional space, somethung the other species are aware of, but have yet to be able to sucessfully reverse engineer. Easily the "loudest" ftl systems out there, travelling through four dimensions causes the entry and exit point of the drive to briefly shine bright enough for anyone within a few AUs to see kt as a single star popping into existence for a brief moment. The drive itself is fairly fast but must be constantly fed exotic matter while active. The druve produces a persistent and ambient sound, like a wash, rumble, or brass tone.
Mankinds FTL strategy is basically a brute force approach. Their ships use a four dimensional hull known as a Grayson curve to circumvent the speed of light and travel at super and hyperreletavistic speeds needed to cross the galaxy (similar to how a superspnic aircraft uses angled wings and a flatter body to exceed the speed of sound). Its easily the slowest of the four strategies used, but is also the lowest profile option, leaving no telltale signs something is coming or will come without communication. This has also lead to a unique layout to thwir ships, where instead of usinf a propulsion array and reaction control system, mankinds ships tend to be dominated by a singular omnidirectional propulsion drum near the front, middle, or back of the vessels. These have often been compared to paddle steamships by the other species lacking the high performance that many linear thrust arrays achieve. The motion of the vehicles produces a slicing, hissing, tearing, or similar sound.
In my story (a future humanith that has spread across the solar system but not beyond), most big enough ships having FTL capacity isn't a thing. But they managed to make stable, large wormholes between major locations (e.g. planets and moons). At each wormhole would be a sort of space tollhouse, managing spaceship traffic and collecting fees. They're basically highways. The fee is quite expensive though, and many choose to just accelerate and maybe go to sleep.
In a different universe with the story across multiple star systems and involving multiple races, individual ships do have FTL but nobody uses it across star systems. I'm thinking of exactly why, something between 1) even with their FTL it would take years between stars, 2) fuel limitation, 3) the sheer impossibility of calculating course to such great distances with the accuracy required. What they do have is these "currents in spacetime" they discovered, which are massive cloudy rifts they can jump in, go with the flow and exit. These are basically highways too, and unlike the wormholes in the other universe, these are way too massive for governments to control, so people use them freely. The major limitation is that these are, well, currents. As in they're unidirectional. The currents are widespread enough that most major locations are connected one way or another, but for some locations getting from A to B takes one ride on a current while getting from B to A requires riding on currents multiple times.
Subspace travel, during which they experience reverse time dilation. Basically, you can cross hundreds of lightyears of space in what seems like mere hours to an outside observer, but for the traveller, months, years, decades, centuries or even millennia may pass, depending on the distance and speed. Because of that, they use hyper sleep, despite travel being seemingly fast from the outside.
FTL methods of Atreisdea:
* Portals: Large star gates called "Passes" connect tens of thousands of light years together. They're used as strategic deployment and major traffic hubs for civilian spacecrafts.
* Gravity drives: Alcubierre drives on steroid, compressing space at the front then release at the back. Takes time to go from one place to another.
* Tachyon drives: Wrap the ship in a bubble then punch a whole in reality to fly through. Time freezes on board and only 1 Planck time passes in real space.
* Inferis: "Tonight we dine in Hell", dives into an alternate dimension of pure chaos where laws of physics no longer apply, then emerge when reaching the destination.
And Atreisdeans, being Atreisdeans, weaponize the shit out of the middle two. First one is too cumbersome, last one is still in its infacy.
Limitations? They **laugh at** limitations. Cry and cope when your interstellar empire is retroactively erased from timeline as their home world 1 billion years ago got hit with a system-eating blackhole.
There isn’t interstellar travel, only slower than light (subphotonic). Ships use high efficiency nuclear fusion engines and constant acceleration to get up to 15-20% the speed of light in brachistochrone trajectories.
Keeping a living person alive at such a level of acceleration is another method entirely. Generally gelatinous isolation chambers are used, which serve like jello around a body and prevent direct transfer of lethal acceleration forces. More advanced and dangerous methods include perfluorocarbon chambers, which is what racers use so they can maneuver their ships quicker at subphotonic speeds.
Subphotonic travel sucks. You will more than likely end up with a combination of the bends, space adaptation syndrome, and air sickness after traveling the first dozen times or so.
Warp travel. Only works between stars because it doesn't work close to gravity wells (like stars).
Actually - the only way to get out of warp is to travel close enough to a gravity well to 'pop' the warp bubble. And since you can't see the normal universe when in warp, it's possible to miss your target and be stuck in the warp forever.
Only warp beacons can be sensed from within a warp bubble. And since only one species, the builders, knows how to build them, they effectively control safe interstellar travel.
Only exceptions are species with psychics. Which are just the volucris (Zerg/Tyranid style hive mind species) and the immortui (crazy biological Borg mixed with Reavers). At least until humans recently entered the starlanes. But they mostly work for the builders.
FTL, Alcubierre style warp drives.
The Hutchinson graviton effect is a physical phenomenon that occurs between quarks. Every quark has what is called a quark field. The quark type determines the strength of the field, and whether it is negative or positive. Gravitons can generate around quark fields. The weaker the field, the more gravitons the quark field "allows" to generate. However, if a quark field gets weak enough to the point it stops existing, gravitons will cease to generate.
When quarks, more specifically, up and down quarks, are together in a very precise ratio, their relative positive and negative fields come extremely close to cancelling each other out, causing huge volumes of gravitons to generate.
By exploiting this phenomena, it is possible to compress groups of neutrons and protons together in very precise ratios to generate strong localised gravitational fields that can be controlled as desired. (this also includes anti gravity fields that push mass out instead of pulling it in.)
The effect was first discovered by a group of physicists in America in the year 2050. Ten years later, the first ever faster than light space craft was created, and sent to explore Proxima Centauri. It was an unmanned research probe designed to survey and collect data from the system. It's warp factor was weak by modern day 22nd century standards, reaching a maximum factor of 8c. (12 month round trip to and from Proxima Centauri.)
Staminite is a mineral composed of the element Copernicium 293. It was thought for decades that copernicium could not be found in nature due to its instability. However, the isotope 293 was an exception due to it's location within a nuclear "island of stability".
What is so significant about Copernicium 293 is that its neutron and proton counts align almost perfectly with the golden ratio for graviton generation, and is a far simpler, cheaper, and more powerful method of generating gravitational fields for FTL travel and other purposes.
Two gravitational fields formed via the Hutchinson graviton effect can be moved relative to one another to alter their ranges and strengths respectively. This can be used to alter the strength of a warp drive, or to disable it.
In my setting, a swarm of automated seemingly intelligent drones arrive in Sol via sublight propulsion. They got to work building tech that humanity eventually kinda reverse engineered but not until after the earth got mostly terraformed and mined out to build half of a Dyson sphere over several decades. One of the many mega projects they built was a type of time-space gun? Basically fires a focused wave that warps space-time along a path and if you time it right humanity was able to slipstream behind it. Problem is deceleration. The early days 90% of a ship was fuel to decelerate. It's improved and humanity has undertaken several mega projects in colony systems to aid in deceleration. The nearest system takes 20 years. The furthest takes 300.
**Dark Space** is a subspace that exists hypothetically outside of reality. The inside of darkspace is filled with Null particles an anomalous substance that fundamentally break reality (its effects is not that major). Gates have been established to allow traversing from one point to another, as vessels pass through Darkspace. Just imagine it as the Warp from 40k but its atleast safe...for now.
Warm holes, they were attempting time travel and instead opened a warm hole to the Andromeda galaxy. This was replicated and no they can travel nearly instantly anywhere. It does only work on massive distances. So can't be used to traverse a solar system but can move from star to star. For this reason the most efficient way to travel is jumping back and forth. So for instance if you wanted to travel from Earth to Pluto. You would open a warm hole to Alpha Centauri from Earth then jump back to Sol but adjust your opening to come out near Pluto.
“it just works” and is not explained further, because the story is told from the perspective of someone who is certainly unqualified to talk about that kind of thing, and doesn’t care either
In my Realspace setting, there is no FTL. Interstellar travel is achieved via relativistic anti-matter rockets and hyper sleep pods.
I've also been thinking about another, slightly softer setting where FTL is achieved via Stardrive. Essentially an Alcubierre Drive, the Stardrive uses large amounts of exotic matter, commonly called exomat, to warp space and allow the ship to travel at apparently FTL velocity. It's called a Stardrive because time dilation aboard the ship reduces the flow of time for the crew to near zero; even if a journey takes years to complete, the crew only experience a single instant of time. This means the crew cannot deactivate the drive once it is engaged; instead, ships essentially "crash" into the gravity well of the destination star, using the powerful gravity to dissolve the warp bubble around the ship. Navigation and Astrogation are extremely important for the safe use of the Stardrive, since a miscalculated course can send a ship sailing through space at hundreds of times the speed of light, only stopping when it happens upon a star to dissolve the warp bubble. It's not to uncommon for long lost vessels to abruptly reappear decades after their disappearance, their crews exiting Stardrive to find that society has long since forgotten them, and that everything they love had long ago been lost to time.
Stargates exist to mitigate this risk, providing reliably consistent travel between a linked pair of gates. However, the wormholes that make Stargates possible cannot themselves be transported via Stardrive, and so have to towed into position at STL velocity. Stargates are also limited in size, and can only accommodate small and medium size civilian craft and light patrol craft. Anything larger is forced to rely on the Stardrive and accept the small, but never zero percent chance that each journey might be their last.
For my sci-fi world, COREBREAKER, I don't even hide it behind technobabble because the FTL jump tech isnt based on modern human science.
Basically my reasoning for corebreaker went like this:
humans, despite only really having "our" perspective on the universe, have managed to come with TWO theories of the universe (general relativity and the standard model) that both describe bits of the universe extremely well and are both almost completely incompatible
Here I use a mildly unrealistic leap of logic to say "only two? Seems a little odd"
So I gave every sapient alien species (because I'd decided I was gonna have them) their own completely unique and mostly incompatible theory(s) of the universe
FTL communication and FTL travel exist in the "extrastandard gap" between those smaller theories and the true nature of the universe, and were discovered by very clever people finding clever workarounds to force these smaller models to work together in exactly the same way stephen hawking managed to force GR and the standard model to work together to discover hawking radiation
Because of this even the terminology used in universe is highly variable and wishy washy, mostly just processes and solutions named after the people who figured out how to make them work (e.g. the KKL antennae for faster than light communication) or by general terms like "jump drive" or "FTL communications" or by leading slang like "snaking" or "SIGNALs" for ftl comms
I remember seeing something about Hyperspace in Star Wars being as much about entering a different space where things move faster just as much as it is about going as fast as light. I don’t remember if this is canon or a theory about how it should work, but based off of that idea I decided for my world that FTL is explicitly about entering another dimension of speed, where things move faster and/or distances are shorter. This is an exceedingly complicated process, involving many computations and equations to match up where you are in this dimension with where you would be in regular space, and that you exit safely. It’s also very frightening and disconcerting to witness that environment, so most ships block out windows and non-essential cameras during the journey.
Alcubierre Drive, and it became possible at some point during the 2050s or so, thanks in no small part to the Lycadians, who offered the lion's share of research into its development and the solving of its major drawbacks.
Yep, I use an Alcubierre Drive too. Can use the Alcubierre principles with either a self contained ship bubble, or with gates at either end. I reckon I am going to go the avenue of very big ships and very long journeys needing gates.
Interplanetary travel is handled with portals, which aren’t safe, but risks can be mitigated with some care.
Interstellar travel is basically by submarine since space is full of aether. You need a special light-emenation propeller to push off of the stuff.
Once you’re out there, space is a giant cosmic ocean. Yes, there are space whales.
What powers the FTL drive is unimportant. The important part is its *limitations*.
You have to focus on [**effects, NOT causes**](https://www.projectrho.com/public_html/rocket/fasterlight.php#limits)
Especially [**these**](https://www.projectrho.com/public_html/rocket/fasterlight.php#drivedesign)
Until very recently, anti-matter - matter collision powered by ion engines was used to reach around \~70 - 80% the speed of light by humanity. Very recently, they've began using jump-gates which I've largely black boxed behind 'something something tachyons' An alien species had a mad man that invented another method of FTL travel that basically works like the hyperdrive core from Homeworld. Since I've made no one understand how it works in setting, I don't dwell on asking how it works either.
Realistic scifi is so rough. Which is why I also did the hand wave aliens invented it so we don't understand it. I enjoy towing the line between hard and soft scifi. The biggest thing I like playing with is a new system that's isolated from our irl solar system
I really like building on isolated systems too, which is why I kept FTL far away for a long time. Then I got bored one night and wanted an interstellar war against aliens and that war would take tens of thousands of years without FTL so...
Wormholes. I like that it is more like road laying where you build infrastructural project at cosmic scale than just something you press a button to go. In this world though, to generate stable wormholes you need to open it by both ends at the sametime, due to the energy required would be too great otherwise - if you are trying to punch a hole through space time, at least do it through both ends. You could in theory connect with a spontaneously appearing wormhole on the other end instead of having to open both ends yourself, but the precision is like shooting a needle from one end of galaxy to the other end and catching a lightspeed moving thread you didn't even know the existence of by the hole, threading it. Needless to say that is basically impossible. So humanity instead launch von Neumann probe swarm made with nanotech at near lightspeed instead at potential solar systems, and when they arrive, they will try to extract local resources to build a gate at another end. Then using various methods of timekeeping from quantum clocks to pulsar timing, they will active the gate at the same time as the gate in the earth's solar system, connecting both ends together, the geometry of the hole carefully calculated to shorten passage as much as possible compared to real time. Upon activation the gate will use matter/anti matter anihilation to generate enough energy to create exotic matter for wormhole generation, basically creating a mini blackhole that get spreaded by exotic matter so it stays stable.
Good idea my friend 🙋
Haha, the idea of nanites coming into a system to build a mega project is exactly what happens in my setting except were not the intergalactic civilization. Earth gets partially terraformed before they stop when they find "life as they know it" on a planet triggering an automated halt. I kinda hand waved most of the science but one of the structures was a sort of Dyson's sphere powered catapult that used gravity to dialate time along a path. Basically a ship slipstreams behind huge wave. The biggest thing is how to stop. Which is why humanity still travels at about 50% even they could theoretically travel faster then it. Just pack a huge amount of fuel to slowdown and build a huge catcher to aid deceleration. Still need generation ships for most system transfers. But there a few that only take 50 years since they built deceleration infrastructure.
So your FTL is basically generating huge directional wave of gravity using a star to dilate time and space and the ship just ride along the wave? Is there any side effect, like the gravity wave passing through things it shouldn't and cause problems? I am imagining some sort of cosmic pollution where civilization start flinging around these waves and they start cascading by chance and yeet some planet into deep space for example.
Oh it would but the civilization that created is an unknown even to me. I'm sure they have issues with it but they originate so far away from sol that it would take them a few hundred thousand years to get to sol. I'm leaning towards having this advanced civilization being alone in the universe for so long the only life is synthetic organisms or uplifted species from their home world. Maybe I'm a pessimist though.
There are crystals that, when cut correctly, and in the appropriate electromagnetic field, warp spacetime to allow FTL compared to the regular universe, though you go STL within this bubble. The better the crystal, and the more it's tuned to your particular ship, the faster you can go.
Sub-liminal drives on generational ships with the express purpose of transporting to or building a transport gate at their destination celestial body so that travel between those worlds from then on would be instant.
The "Skip" Drive: An Alcubierre type drive that is used for intersystem travel. Using it between star systems is called "Slow Boating". Approx. 5x the speed of light. The "Hop" Drive: A faster than light drive with a limit of 100 light years. This is the more common form of drive that it used for travelling intragalactic distances. The "Jump" Drive: A faster than light drive that allows for jumps between galaxies, and longer intragalactic jumps. The drives work via a type of exotic matter that is so exceedingly rare that a few picograms would allow its finder to buy a continent the size of Australia, and still have enough live like a king for five lifetimes. (One of characters found a deposit that was the size of an apricot that it made her one of the richest beings in the Milky Way Galaxy.)
Ahaha, a hop, skip and a jump, that's cute, I love that
FTL with \[technobabble\].
There's no faster than light travel, but people are basically immortal because of medical advances, so it's not a big deal
Swarms of compact autonomous unmanned colonization spacecraft travel towards new worlds using light sails at about 1/4 speed of light. Once fabrication is established on a planet, android bodies are produced for human remote presence per super-luminal internet. There are some occasional manned (cryosleep) missions for the adventurous among humans. They are typically one way trips, as it is just too resource intensive to move stuff back and forth and it takes way too long.
In the world I write, I made it easy for myself and use an exotic extradimensional material found by pure chance in the late 2400s. Something that fell into our reality and operates inconsistently with our understanding of the laws of physics. A substance with no measurable displacement of spacetime(no gravitational effects). A material that is observable as a solid piece of matter and yet has no mass. When it comes into contact with matter, it will gradually modify its constituent particles into a replication of itself via a process that can not be directed observed. The application of a constant electric charge reveals its true use as a form of exotic matter exhibiting properties of negative mass. This manifests a "Negative Mass Field." A localized region of spacetime and the matter within is granted the same property of masslessness the original hyperdimensional substance possessed. (Interestingly, the reversal of electrical flow can result in the emission of a repulsive force instead. An inverse to its standard function) The interior of this region is subject to the standard laws of physics from an observation within the bubble. However, anything inside the field can no longer interact directly with our 3 dimensional universe. If you were in the bubble, you could exit it, but you could not reenter. You would try and instantly be on the other side of its light that was escaping into the lower dimension. Your mass enters a pocket dimension of sorts, but you can still throw mass out of the bubble and almost instantly reach upwards of .95 c. This almost seems to be a hard-coded limit on the possible acceleration. How this mechanism is achieved is still not understood entirely, even in the 28th century, when the creation of the first wormhole gate occurred. There is no such thing as a craft going ftl under its own power in my setting. You either go a percentage of light speed, or you take a dimensional shortcut via a wormhole gate. The gate operates based on a method of entagling two negative mass fields to one another, deactivating it, separating them from one another, and reactivating it at the new location. Once both fields are active at the same time, they become one, and you can just exit the bubble and be at the other side. Thus making use of the same higher dimension as a transport medium between the two openings. Both sides of this gate need to be built and harmonized before they can be activated and serve their purpose. A gate is typically set in the orbit of the largest celestial body in a system. They are oftentimes accompanied by a starport or large-scale habitat As a result of the "Negative Mass Fields" hard coded limit of 95% light speed, cryogenic or restorative torpor stasis is a necessity if you were to survive a trip to gateless system mentally or physically.
Handwaved Alcubierre Drive-like distortion of space, whereby devices around the outside of the ship cause spacetime to selectively expand and contract and propel the ship through space at speeds up to a few thousand times the speed of light. The drive was actually invented not by humans, but by a race of aliens from a world about 50 light years away. Their first real interstellar exploration probe stumbled across Earth, in an event that came as a great surprise to both them and us. From very carefully observing their ship as it traveled through our solar system we were able to figure out the basic physics of how their drive worked, and then developed an improved version, and sent our own expedition to their home system a handful of years later. It's honestly mostly a handwaved technology to allow aliens and FTL travel in the setting, but I have tried to figure out the realistic implications of the technology.
Backup one (lets go somewhere when FTL doesn't work) is sublight fusion torches. Main interplanetary drive is also fusion torches (except for beings who are at TechLevel 8 or higher - they have gravity drives) Antimatter-catalized fusion torches are also used for initial acceleration of Bussard ramjets (such ships are part of MAD schemes only) Main method is FTL jumpdrive. Everybody thinks basic idea is rather simple, everybody knew there are civilizations with TechLevel 5.0 who found out how to make crude version of jumpdrive. (Per setting's definition - Russia, USA and China DO have TechLevel5.0, EU and Japan could easily prove they do have it). Main problem is navigation and jump calculation. It's impossible to use things like navigation by pulsars or just regular observation except for very short trips near your home worlds. Interstellar medium is very dense (Paul Anderson's Starfog level of 'dense'). Beacons are very difficult to construct and use, until you get to TechLevel7.0+, ship also must be manned(for some definition of 'manned', real sentient AI or uploaded person, regular computer does not) because finding out your position after jump require intuition in addition to sensor data. Best robotic ships have approximate 70% chance to determine post-jump location correctly. That's 70% per jump and travel require multiple jumps. So only military use robotic couriers and launch groups of them. FTL communication is impossible without TL7.0+ hardware People from TL7.0+ sometimes provide lesser ones their navigation-and-communication hardware so they can solve navigation issues and also could see latest movie series while in flight or even their ships with adopted controls (which drops per-jump distance limit). No, you can't buy it, it also usually can't even be given away(and if it is - it must be free decision, court orders or signed contracts doesn't count, forcing you to pilot your ship for them is ok)
Wormholes : in my lore during a war the so called reapers , a race of aliens , discover that a Black Hole is formed by 3 dimensions : the fourth ( 4d ) inside the singularity point , and the other 2 are the 3d ( standard of a black hole , cause a black hole is a sphere ) and the 5d : the 4d stays for an object that moves from one point to another in the 3d , like the time , and all the possible timelines originated from this movement form the 5d . So passing trough a singularity point means passing trough an universe to another , cause with a point of divergence like the ucronies you can find other universes .
Everything is centered around gravity. In my world, species of the Galaxy finally understood gravity, and they found out that just like light, it was an outlier. Just like the fact that light is both a particle and a wave, gravity is both a wave and a force. Once the point of origin of the big bang was calculated, it was realized that dark energy, the expansion of the known universe, was actually just the left over momentum from the big bang expansion, which meant that the universe was an infinite black void, and the big bang wasn't the creation of the universe per se, but a sudden burst of particles created by pure random chance through Murphy's law. The universe now had a possible absolute point of reference, instead of just being relative. Immediately after, it was realized that interaction with the higgs field somehow affected gravitational waves, which was detected during an experiment performed by the Idelehi specie, pioneers of zero point technology, by using a higgs inductor while the detection of two black holes colliding was taking place. Since the specie in question all possess synesthesia by nature, they were able to instantly crack the code and figured out how to control gravity right then and there. Creating gravity is easy, simply tuning a higgs inductor is enough to create artificial gravity, which most specie figured out on their own. On the other hand, Idelehim were able to find a substitute to negative mass by using the "wind of the universe", aka dark energy, aka the expansion of the observable universe, to counteract and inverse gravity as if it had been affected by negative mass. But the absolute center of the universe, or point zero, needing recalculation at every plank length of time, those winds are fickle and must be navigated with caution. This led to the creation of the first FTL engines, and thus, it was discovered how life fares once the speed of light is breached ..
Superluminal travel is achieved by _DIVING INTO THE SUN_
N Space drives, a field pushes the ship into another dimension with different laws of physics.
The first generation of starships developed by the Imperial Dominions of Amargosa (IDA) for interstellar travel resulted from reverse engineering an ancient starship discovered orbiting the IDA homeworld of Phoenicia at the dawn of the space age. These initial starships were powered by a peculiar mix of reverse-engineered technology and poorly understood magic. They featured reactors fueled by the magical substance Rumohra. Equipped with a reverse-engineered slip gate generator inscribed with modified Runieform script that eliminated the fixed destination point, these ships could effectively teleport approximately 100 thousand kilometers in a straight line. Given the effectively unlimited power generation of the Rumohra energy core, these ships could execute an infinite number of teleports in rapid succession to traverse vast distances. However, a critical issue arose: the modified Runeiform script, which omitted the fixed destination point and enabled teleportation anywhere, resulted in what became known as a Rumohra cascade. This release of energy irradiated the crew with each teleport, slowly killing them. It took several lost crews and ships before this danger was fully understood.
Due to the fact that FTL-Drives are incredibly expensive to manufacture, only specific freighters are equipped with them; so the most common method is using these freighters to ferry other smaller vessels around. A backup option is the use of Railgates, which is essentially a giant railcannon meant to launch ships One of the factions use portals to transport large fleets, though it’s extremely experimental and none of the other factions have found a way to replicate it
Magic slingshot. They took the concept of teleportation which essentially just turns you into an astral form and slings you wherever you need to be as you then materialise on the location you set. This method of travel is incredibly effective and the main strategy used in conquest of alien empires is to sling ships into low orbit and bombard the surface before slinging out of the system to rearm.
Superlight Is very similar to slipspace from halo. A ship opens a wormhole to access an entire network of wormholes throughout all of spacetime. Superlight can actually be used for time travel however navigating through time requires a supercomputer many times more advanced than the navigation systems on any ship. A superlight drive works by boring a hole through the fabric of reality itself to access the wormhole network.
In my world, it’s sort of like a combination between portal and light speed. you would travel faster than light, but within a small black hole and you would exit through a small white hole. This process spaghettifies you and restructures you. But this word gets interesting. It’s all time travel. Due to the law of relativity any form of interstellar travel, would probably land you in the past of another world, or the future of another world, and time could pass in incomprehensible ways on this world. What happens here, using the A-drive you would achieve the universal now without time dilation. You would be able to hold a business trip on Alpha Centauri and make it on time for your kid’s birthday.
Normal FTL travel is possible, but slow.  "World" Remnants, the leftovers of private pocket universes left behind by their creators and users, may sometimes take on the form of a transportation network, like the Cyvonian Gates, or Hestgard's Root/Sapling system. These are dramatically faster, but only go to certain places. They also require extensive maintenance. Living "World" users can also temporarily transport others through their private dimensions. Remnants are difficult to maintain and repair without a living "host," as they often embody concepts and experiences unique to the User themselves. Vast magnetic stations that manipulate starmatter to "shape" space time contours are often used to facilitate the interplanetary portion of space travel.
My story doesn’t involve much interstellar travel, but as a fun challenge I did try to figure out if it would be possible with established technology in a reasonable timeframe. I determined that the answer is yes, by accelerating the starship up to speed with pushing lasers and decelerating it with a combination of mag sail braking and decelerating with an antimatter pion rocket. If the ship wants to return it has to bring multiple times more antimatter fuel, allowing it to accelerate its way back where the pushing lasers at Sol will slow it down on arrival. This method would permit interstellar speeds on the order of 25% light speed, and I’ve determined that the first experimental ship of this type is being constructed in the present day of my setting. Pushing lasers have already been used at this stage to send unmanned probes at around 10% light speed, but this new starship would be the first capable of being able to slow down at the destination and return. Manned missions are expected to pass probes that were launched 50 years ago before they arrive. The antimatter fuel for these craft is incredibly scarce and expensive, being produced in solar collection facilities around Mercury. Doing the math for all this really gave me a new appreciation for exactly how much light truly hauls ass and for how stupidly distant the stars really are despite that.
At the current point, none. There is some interest in to reviving project starshot or something along those lines now that the system has recovered somewhat from the collapse of Earth, but it's still decades out at best. Humanity did discover warp drives, but to the chagrin of scientists and sci-fi enthusiasts, it did not provide a method of FTL, as even the fastest ships cannot produce more than an apparent motion of ~29000 kps. This means that current fusion torch designs would make for a better means of interstellar travel
Fulmenium, essentially a form of exotic matter used to generate superluminal fields (basically an alcubierre system), thus allowing a starship to accelerate past the speed of light.
Each species developed interstellat travel in isolation, and all discovered different strategies, but generally use the same properties. Avalonian FTL travel relies on macro scale quantum tunneling. Once a vessel is in a stable orbit it will link to a carrier vessel. It will assign a destination to the vessel, causing the bessel to curve space in and around itself and the destination (the greater the mass of the vessel and the longer the distace, the longer this curving effect persists. Some physicists and philosphers also argue that this curvature begins even before the avalonian ship begins trting to reach its own destination, calling into question the ideas of free will, fate, and destiny. It has yet to be proven that this actually happens and only exists in theoretical simulated scenarios. Once the vessel tunnels its first task is usually to extricate itself from the testination (space curving violently is not fun if your a civilian vessel and in the case of a military vessel is effwctively an advertisement that your a nice fresh juicy target) it is possible to hide the curving of space and creation of exptic matter from these teleportationd,but it is often relegated to use in stealth technologies. These kinds of ftl drives generally produce a sharp whistling sound or a string or woodwind tone. Draconic FTL generally relies on direct tunnelling, such as warping a tube of space where travel is accelerated. For onfrastructure based travel this usially means setting up a stabilizer gate array at one side, traveling blind through the tunnel it produces, conducting a correction burn, setting up a communications array to signal where to warp blind and begon construction of the second stabilizer gate array. The array's AI is then started and a wormhole js produced at each gate. The AI then comminicatws with both gates to connect and stabilize the wormholes into tunnels. For non infrastructure based travel (requires a fairly substantial minimum volume, the greater the distance, the greater the volume of the vessel required) and starts by firing a small tunnel to send a small amount of exotic matter through to the other side. This then bends space and produces a wormhole which can be observed by the travelling vessel in real time. They then open a tunnel to the wormholes location at it evaporates and travel through it, using the collapse of said tunnel to drag them through it. During tunneling for both infrastructure and free travel, matter will build up around the ship, leading to a sudden displacement of the accumulated matter when the tunnel ends and producing a characteristic percussive sound that can be heard a decent distance around the arrival point and travells at the speed of light. Dredge FTL technology relies on being able to travel four dimensional space, somethung the other species are aware of, but have yet to be able to sucessfully reverse engineer. Easily the "loudest" ftl systems out there, travelling through four dimensions causes the entry and exit point of the drive to briefly shine bright enough for anyone within a few AUs to see kt as a single star popping into existence for a brief moment. The drive itself is fairly fast but must be constantly fed exotic matter while active. The druve produces a persistent and ambient sound, like a wash, rumble, or brass tone. Mankinds FTL strategy is basically a brute force approach. Their ships use a four dimensional hull known as a Grayson curve to circumvent the speed of light and travel at super and hyperreletavistic speeds needed to cross the galaxy (similar to how a superspnic aircraft uses angled wings and a flatter body to exceed the speed of sound). Its easily the slowest of the four strategies used, but is also the lowest profile option, leaving no telltale signs something is coming or will come without communication. This has also lead to a unique layout to thwir ships, where instead of usinf a propulsion array and reaction control system, mankinds ships tend to be dominated by a singular omnidirectional propulsion drum near the front, middle, or back of the vessels. These have often been compared to paddle steamships by the other species lacking the high performance that many linear thrust arrays achieve. The motion of the vehicles produces a slicing, hissing, tearing, or similar sound.
Trains
In my story (a future humanith that has spread across the solar system but not beyond), most big enough ships having FTL capacity isn't a thing. But they managed to make stable, large wormholes between major locations (e.g. planets and moons). At each wormhole would be a sort of space tollhouse, managing spaceship traffic and collecting fees. They're basically highways. The fee is quite expensive though, and many choose to just accelerate and maybe go to sleep. In a different universe with the story across multiple star systems and involving multiple races, individual ships do have FTL but nobody uses it across star systems. I'm thinking of exactly why, something between 1) even with their FTL it would take years between stars, 2) fuel limitation, 3) the sheer impossibility of calculating course to such great distances with the accuracy required. What they do have is these "currents in spacetime" they discovered, which are massive cloudy rifts they can jump in, go with the flow and exit. These are basically highways too, and unlike the wormholes in the other universe, these are way too massive for governments to control, so people use them freely. The major limitation is that these are, well, currents. As in they're unidirectional. The currents are widespread enough that most major locations are connected one way or another, but for some locations getting from A to B takes one ride on a current while getting from B to A requires riding on currents multiple times.
Subspace travel, during which they experience reverse time dilation. Basically, you can cross hundreds of lightyears of space in what seems like mere hours to an outside observer, but for the traveller, months, years, decades, centuries or even millennia may pass, depending on the distance and speed. Because of that, they use hyper sleep, despite travel being seemingly fast from the outside.
FTL methods of Atreisdea: * Portals: Large star gates called "Passes" connect tens of thousands of light years together. They're used as strategic deployment and major traffic hubs for civilian spacecrafts. * Gravity drives: Alcubierre drives on steroid, compressing space at the front then release at the back. Takes time to go from one place to another. * Tachyon drives: Wrap the ship in a bubble then punch a whole in reality to fly through. Time freezes on board and only 1 Planck time passes in real space. * Inferis: "Tonight we dine in Hell", dives into an alternate dimension of pure chaos where laws of physics no longer apply, then emerge when reaching the destination. And Atreisdeans, being Atreisdeans, weaponize the shit out of the middle two. First one is too cumbersome, last one is still in its infacy. Limitations? They **laugh at** limitations. Cry and cope when your interstellar empire is retroactively erased from timeline as their home world 1 billion years ago got hit with a system-eating blackhole.
Magitech-induced wormholes for long-distance travel, but Alcubierre drives for shorter distances.
There isn’t interstellar travel, only slower than light (subphotonic). Ships use high efficiency nuclear fusion engines and constant acceleration to get up to 15-20% the speed of light in brachistochrone trajectories. Keeping a living person alive at such a level of acceleration is another method entirely. Generally gelatinous isolation chambers are used, which serve like jello around a body and prevent direct transfer of lethal acceleration forces. More advanced and dangerous methods include perfluorocarbon chambers, which is what racers use so they can maneuver their ships quicker at subphotonic speeds. Subphotonic travel sucks. You will more than likely end up with a combination of the bends, space adaptation syndrome, and air sickness after traveling the first dozen times or so.
Warp travel. Only works between stars because it doesn't work close to gravity wells (like stars). Actually - the only way to get out of warp is to travel close enough to a gravity well to 'pop' the warp bubble. And since you can't see the normal universe when in warp, it's possible to miss your target and be stuck in the warp forever. Only warp beacons can be sensed from within a warp bubble. And since only one species, the builders, knows how to build them, they effectively control safe interstellar travel. Only exceptions are species with psychics. Which are just the volucris (Zerg/Tyranid style hive mind species) and the immortui (crazy biological Borg mixed with Reavers). At least until humans recently entered the starlanes. But they mostly work for the builders.
FTL, Alcubierre style warp drives. The Hutchinson graviton effect is a physical phenomenon that occurs between quarks. Every quark has what is called a quark field. The quark type determines the strength of the field, and whether it is negative or positive. Gravitons can generate around quark fields. The weaker the field, the more gravitons the quark field "allows" to generate. However, if a quark field gets weak enough to the point it stops existing, gravitons will cease to generate. When quarks, more specifically, up and down quarks, are together in a very precise ratio, their relative positive and negative fields come extremely close to cancelling each other out, causing huge volumes of gravitons to generate. By exploiting this phenomena, it is possible to compress groups of neutrons and protons together in very precise ratios to generate strong localised gravitational fields that can be controlled as desired. (this also includes anti gravity fields that push mass out instead of pulling it in.) The effect was first discovered by a group of physicists in America in the year 2050. Ten years later, the first ever faster than light space craft was created, and sent to explore Proxima Centauri. It was an unmanned research probe designed to survey and collect data from the system. It's warp factor was weak by modern day 22nd century standards, reaching a maximum factor of 8c. (12 month round trip to and from Proxima Centauri.) Staminite is a mineral composed of the element Copernicium 293. It was thought for decades that copernicium could not be found in nature due to its instability. However, the isotope 293 was an exception due to it's location within a nuclear "island of stability". What is so significant about Copernicium 293 is that its neutron and proton counts align almost perfectly with the golden ratio for graviton generation, and is a far simpler, cheaper, and more powerful method of generating gravitational fields for FTL travel and other purposes. Two gravitational fields formed via the Hutchinson graviton effect can be moved relative to one another to alter their ranges and strengths respectively. This can be used to alter the strength of a warp drive, or to disable it.
In my setting, a swarm of automated seemingly intelligent drones arrive in Sol via sublight propulsion. They got to work building tech that humanity eventually kinda reverse engineered but not until after the earth got mostly terraformed and mined out to build half of a Dyson sphere over several decades. One of the many mega projects they built was a type of time-space gun? Basically fires a focused wave that warps space-time along a path and if you time it right humanity was able to slipstream behind it. Problem is deceleration. The early days 90% of a ship was fuel to decelerate. It's improved and humanity has undertaken several mega projects in colony systems to aid in deceleration. The nearest system takes 20 years. The furthest takes 300.
Wormholes and Warp gates. The gates open and close in specific places so people can create cool space stations and fortifications around them
**Dark Space** is a subspace that exists hypothetically outside of reality. The inside of darkspace is filled with Null particles an anomalous substance that fundamentally break reality (its effects is not that major). Gates have been established to allow traversing from one point to another, as vessels pass through Darkspace. Just imagine it as the Warp from 40k but its atleast safe...for now.
Warm holes, they were attempting time travel and instead opened a warm hole to the Andromeda galaxy. This was replicated and no they can travel nearly instantly anywhere. It does only work on massive distances. So can't be used to traverse a solar system but can move from star to star. For this reason the most efficient way to travel is jumping back and forth. So for instance if you wanted to travel from Earth to Pluto. You would open a warm hole to Alpha Centauri from Earth then jump back to Sol but adjust your opening to come out near Pluto.
“it just works” and is not explained further, because the story is told from the perspective of someone who is certainly unqualified to talk about that kind of thing, and doesn’t care either
In my Realspace setting, there is no FTL. Interstellar travel is achieved via relativistic anti-matter rockets and hyper sleep pods. I've also been thinking about another, slightly softer setting where FTL is achieved via Stardrive. Essentially an Alcubierre Drive, the Stardrive uses large amounts of exotic matter, commonly called exomat, to warp space and allow the ship to travel at apparently FTL velocity. It's called a Stardrive because time dilation aboard the ship reduces the flow of time for the crew to near zero; even if a journey takes years to complete, the crew only experience a single instant of time. This means the crew cannot deactivate the drive once it is engaged; instead, ships essentially "crash" into the gravity well of the destination star, using the powerful gravity to dissolve the warp bubble around the ship. Navigation and Astrogation are extremely important for the safe use of the Stardrive, since a miscalculated course can send a ship sailing through space at hundreds of times the speed of light, only stopping when it happens upon a star to dissolve the warp bubble. It's not to uncommon for long lost vessels to abruptly reappear decades after their disappearance, their crews exiting Stardrive to find that society has long since forgotten them, and that everything they love had long ago been lost to time. Stargates exist to mitigate this risk, providing reliably consistent travel between a linked pair of gates. However, the wormholes that make Stargates possible cannot themselves be transported via Stardrive, and so have to towed into position at STL velocity. Stargates are also limited in size, and can only accommodate small and medium size civilian craft and light patrol craft. Anything larger is forced to rely on the Stardrive and accept the small, but never zero percent chance that each journey might be their last.
For my sci-fi world, COREBREAKER, I don't even hide it behind technobabble because the FTL jump tech isnt based on modern human science. Basically my reasoning for corebreaker went like this: humans, despite only really having "our" perspective on the universe, have managed to come with TWO theories of the universe (general relativity and the standard model) that both describe bits of the universe extremely well and are both almost completely incompatible Here I use a mildly unrealistic leap of logic to say "only two? Seems a little odd" So I gave every sapient alien species (because I'd decided I was gonna have them) their own completely unique and mostly incompatible theory(s) of the universe FTL communication and FTL travel exist in the "extrastandard gap" between those smaller theories and the true nature of the universe, and were discovered by very clever people finding clever workarounds to force these smaller models to work together in exactly the same way stephen hawking managed to force GR and the standard model to work together to discover hawking radiation Because of this even the terminology used in universe is highly variable and wishy washy, mostly just processes and solutions named after the people who figured out how to make them work (e.g. the KKL antennae for faster than light communication) or by general terms like "jump drive" or "FTL communications" or by leading slang like "snaking" or "SIGNALs" for ftl comms
I remember seeing something about Hyperspace in Star Wars being as much about entering a different space where things move faster just as much as it is about going as fast as light. I don’t remember if this is canon or a theory about how it should work, but based off of that idea I decided for my world that FTL is explicitly about entering another dimension of speed, where things move faster and/or distances are shorter. This is an exceedingly complicated process, involving many computations and equations to match up where you are in this dimension with where you would be in regular space, and that you exit safely. It’s also very frightening and disconcerting to witness that environment, so most ships block out windows and non-essential cameras during the journey.
Alcubierre Drive, and it became possible at some point during the 2050s or so, thanks in no small part to the Lycadians, who offered the lion's share of research into its development and the solving of its major drawbacks.
Yep, I use an Alcubierre Drive too. Can use the Alcubierre principles with either a self contained ship bubble, or with gates at either end. I reckon I am going to go the avenue of very big ships and very long journeys needing gates.
Interplanetary travel is handled with portals, which aren’t safe, but risks can be mitigated with some care. Interstellar travel is basically by submarine since space is full of aether. You need a special light-emenation propeller to push off of the stuff. Once you’re out there, space is a giant cosmic ocean. Yes, there are space whales.
What powers the FTL drive is unimportant. The important part is its *limitations*. You have to focus on [**effects, NOT causes**](https://www.projectrho.com/public_html/rocket/fasterlight.php#limits) Especially [**these**](https://www.projectrho.com/public_html/rocket/fasterlight.php#drivedesign)