I like the idea of your average star-hopping, rag-tag smuggler in a sci-fi setting actually being really good at calculus, because you would have to be in order to make a living in space.
@ksevio But that's the thing. If the computer fails, you either have to know how to fix it or do the calculations yourself. Both of which are equally funny to think about.
That is not likely, as the math required for maximizing dV efficiency will be phenomenally complex, thus requiring computers. People forget that Apollo's computers weren't the main computers; they were there just for 'that final mile,' so to speak. The real computers of Apollo were massive mainframes at NASA that sent data to Apollo. While we've got computers now that can do what those mainframes did _on_ the spacecraft, we're getting to the point where we'll need pretty chunky computers to maximize dV efficiency. At least until we get CG-NTRs (Closed-Gas Nuclear Thermal Rockets, aka 'nuclear lightbulbs') using water up and running.
I'm pretty sure it's Chewie who handles the math-y stuff. (Though you're right, I imagine han prefers to be able to keep the falcon's tech maintained himself, so he's probably pretty knowledgeable about the machinery)
@@hoojiwana However as another person has said, he still has to maintain the machinery. And, correct me if I am wrong, but there have been several points in time when he wasn't accompanied by an astromech. Though I am not the most knowledgeable on star wars so if you are talking about an actual computer in the falcon then I retract my statement.
One more thing about FTL-capable civilizations is that, when you warp/hop to another point in space, you are seeing starlight, their redshift, and positions, at vastly different points in time. Say, our map of Proxima Centauri's position today, in Earth's inertial frame, is its position 4.2 years ago. And that's the second closest star to us.
very old stars and exogalactic objects like other galaxies and super-stars etc. are already in use for stellar observations and figuring out where things are. anything outside the galaxy should make for a useful reference point in a pinch, if you don't have local starmaps and whatever you use during FTL for navigation (if thats a thing for your FTL system)
Big oof. Not only do you have to calculate position by how many reference points, you have to factor in light delay with each one being it's own variable. Which means you also have to track "when" you are, and "when" you left as well, and of course the faster you go the more varied that can be, as well as passing closer or farther to gravity wells. And as @Edge-wx7hv points out, you might use other galaxies and super-stars for farther reference points, but if you make a blind jump, or get sent somewhere way far off from where you expect to be, or beyond your frames of reference, you might well have no way to tell "where" or "when" you are. Though that last situation is probably a pretty far out outlier. And if we're in a situation where we wind up in a different corner of the universe, we've either got that solved, or we've got way bigger problems.
I love that you are making a few videos on a bit more of the practical matters of spaceflight. In my studies as a civilian mariner we where taught that gps simply works by caculating our distance to any gps satelite. If you have the exact distance to a minimum of three satelites, you know exactly where you are. The distance is calculated by measuring the time it took the signal to reach the vessel ( usually down to a fraction of a mili-second), As Distance= Speed* time traveled, and we know speed and time, this isn't that hard for a computer.
It's a bit trickier than that. First of all, the measurement precision of the time-delay before reaching the vessel is _much_ higher than merely fractions of _milliseconds_ - remember, a "light-nanosecond" is about 1 feet/30 cms. Modern GNSS systems (like GPS) can achieve precision on the order of a few _centimeters_. In other words, you need nanosecond to sub-nanosecond precision to achieve achieve modern accuracy. Secondly, the math involved is far more complicated than merely calculating distances; this has to do with orbital mechanics and even the time-dilation factors from special relativity, as I understand it. (But I'm hardly an expert though, so take this with a grain of salt.)
You can go a level above and use quasars for extra-galactic (maybe out to order 0.1-1B LY) navigation in a similar manner to pulsars as the ~200 brightest have well defined absolute brightness and distance. These quasars are also incidentally, the reference points the GPS satellites use to estabilish their own location as they are far more fixed in space from our perspective than the sun is relative to stuff like pulsars or bright local stars.
Do you know what would be interesting? A combination between using Quasars and Pulsars within a galaxy. Since Quasars are functionally stationary in the night sky, you can use them like a North Star of sorts, with the Pulsars giving a secondary set of coordinates.
@@VelociraptorsOfSkyrim It turns out that pulsars are basically useless in terms of interstellar navigation because the beams they put out are narrow. Even as close as Alpha Centauri you could potentially be out of the beam path of many of the pulsars in an earth-centric database. The location plaques on the space probes mentioned in the video will be completely useless if some other civilization finds them, because they won't be able to see the pulsars used as beacons. Later probes used globular clusters as signposts because they can be seen from any angle.
In one of the later Foundation books, the main character insists on making the hyperspace jump calculations himself (which can take hours or even days) because he doesn't trust the ship's newfangled "com-pyoo-ter" to do it properly.
Now I'm reminded of the "Jumpships" in Battletech, and how they can calculate their FTL jumps with a Human or computer. Said Jumps are limited to 30ly at a time, it takes a week to recharge between jumps, but can be accurate to a few Kilometers. The lore blurb in the "Strategic Operations" Rulebook also mentions how very bad navigators can sometimes "misjump" and find themselves several light-years away from their intended location. Said Jumpships usually find themselves with an open Navigator position shortly thereafter 😂
In Star Wars lore, astronavigation information was regularly updated via the holonet. It seems the Empire could have effectively controlled who could travel where by cutting off updates.
The Empire didn't control the Astronavigation update system. The neutrality of the guilds responsible for it has been paramount to their business since before The Republic was a thing.
@@CantankerousDaveit's only a flat disc in artistic representations in soyrce books because pages in books are flat, in-universe it's as 3D as it should be.
I worked on a sci-fi world where the main form of FTL navigation was based on measuring pulsars. The navigational computer held a large darabase of pulsars and large stars with information to calculate changes based on age. Naturally FTL would mean the signals from the same pulsar were not the same 1000 and 8000 lightyears from it. Navigational accurace was based on how accurate your pulsar database was. However a small angular difference and any gravitational interference would change your trajectory. To nerf FTL but allow for it as a story element travel required a lot of shorter jumps. Constant readings confirmed the accuracy of the navigational system and the computer automatically adjusted jump direction based on it. This was the way to allow FTL travel even for damaged ships. And traveling to other galaxies required getting the appropriate pulsar and system maps.
Did it account for doppler shift/light delay? Your point of observation changing would change how "old" the light from your points of reference would be, so you'd be seeing where it "was" not where it "is" now.
It turns out that pulsars are basically useless in terms of interstellar navigation because the beams they put out are narrow. Even as close as Alpha Centauri you could potentially be out of the beam path of many of the pulsars in an earth-centric database. The location plaques on the space probes mentioned in the video will be completely useless if some other civilization finds them, because they won't be able to see the pulsars used as beacons. Later probes used globular clusters as signposts because they can be seen from any angle. Quasars would work within a fairly big radius, though.
The missile knows where it is at all times. It knows this because it knows where it isn't, by subtracting where it is, from where it isn't, or where it isn't, from where it is, whichever is greater, it obtains a difference, or deviation. The guidance sub-system uses deviations to generate corrective commands to drive the missile from a position where it is, to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position where it was, is now the position that it isn't. In the event of the position that it is in is not the position that it wasn't, the system has required a variation. The variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too, may be corrected by the GEA. However, the missile must also know where it was. The missile guidance computance scenario works as follows: Because a variation has modified some of the information the missile has obtained, it is not sure just where it is, however it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be, from where it wasn't, or vice versa. By differentiating this from the algebraic sum of where it shouldn't be, and where it was. It is able to obtain a deviation, and a variation, which is called "error"
I'm currently reading the Frontlines series by Marko Kloos. "Orders of Battle" has the main character's ship sucked into an Alcubierre bubble, where FTL is capable. In human vessels, the farther the system from the entry node, the longer the transit. When drafted along by the alien vessel, they go farther than ever before, and with the shortest transit time they'd seen. For example, the 150 light year transit requires a full 24 hours in Alcubierre. But the alien bubble takes them 900 light years, over a mere 33 minutes. When they determine their position, they use what is referred to as Galactic Positioning, which uses known pulsars as points of reference. The fine points are not addressed, but they determine themselves to be 900LY from Earth space.
A realistic star tracking system on a galactic scale would need significant computational power, I think, in order to calculate the movement of individual stars from the positions listed in the ephemeris. Another factor is navigating while travelling at relativistic velocities; you have to deal with non-simultaneous, non-causally-linked events being ordered arbitrarily. You also would have to deal with the fact that new stars are born and old stars die; stars which are in the catalogue might not be around any more, and stars which meet all the criteria for being in the catalogue might not be in them, because they were born after the last update of the catalogue.
For solar system nav, I can see us setting up solar system GPS satellites/beacons in lagrange points of each of the planets, just doing the same type of GPS calculations we do now with satellites around our planet, just on a much bigger scale, and it can be just as accurate, and will move with the planets as they move. For interstellar nav, the only real feasible method has got to be Pulsar nav. Those things are very regular and "reliable", and can get you reliably to another star system, or space based installation close enough to use transmitted beacons from the remote system or installation you are approaching, kind of like a layered series of systems. Serious fast nav computing with multiple redundant backup nav computers checking and cross-checking each other would be essential for doing all of this. This is really interesting for a video topic - Thanks for this!
fun fact i had a lecture from the person who discovered pulsars today. i wish i saw this video first so i could of asked about if she thought of or heard of the navigation use. her name is Dame Jocelyn Bell Burnell if anyone is wondering.
I think a great foundation for this subject is Dava Sobel's "Longitude", an essay about how difficult it was to calculate your position at sea during the age of sail.
Hey, I just thought of the reference-star navigation idea myself, mostly because in Starfield Cora Coe keeps saying, "on Earth people used the stars to navigate, but that doesn't work in space" even though in Space there's... pretty much nothing else to use to navigate.
GPS is indeed a very clever and accurate form of military navigation that Reagan released to the public after the Korean Air 007 was shot down by the USSR in the early 80's after it strayed into Soviet air space. I was a young child at the time, but flew on that same Boeing 747 KAL-007 on the same route a year prior.
It was really more of a PR move by Reagan to "release it" - this was before the system was operational, and it was _already known_ that the public would be given access to the CA component of the GPS signal (Coarse/Acquisition); this meant only having precision down to, on average, 100 meters. It was really moreso Clinton who released it such that it took the form - ie., accuracy - that we've become familiar with, by removing the scrambling of the until then military-only component of the signal. And even then this was because of not only high civilian demand, but also that various augmentation schemes with fixed terrestrial transmitters was in use already (thus making the scrambling obsolete), plus that the US military was actively developing ways of jamming the signal to prevent it being used offensively by others.
A cool tracking system that was used in the book series "looking slass" by John Ringo wich used cameras located across the entire ship and mouse image movement tracking software to build a location map and track the ships movement across space
IIRC, Harry Turtledove's short story "The Road Not Taken" offers a unique scenario, where alien species with bronze-age-to-medieval technology also have FTL and gravity manipulation. Humanity is exceptional in having completely overlooked the very simple physical effect by which aliens traverse the stars. It's tangential to the story, but the fact that these otherwise primitive aliens navigate across light years by dead reckoning and memory of major stars-no math or computers involved, I don't even recall if they had drawn charts-was a fascinating detail in that unique story universe.
If I recall correctly, given how far away, the stars are from here, pretty much any solar system within about 13 ly of earth is going to have essentially the same constellations. Some individual stars may be a little brighter or a little bit dimmer, but their sky is basically the same same as our sky. And again, if I recall correctly, you can ghetto out about as far as 35 ly and still recognize the same constellations we see from here. They will be somewhat deformed compared to what they look like in the night sky, butmstill fairly recognizable
@@hoojiwana oh, I know. To be honest, I’m not sure why I posted that, other than I thought it was interesting. Given how low tech a sextant is, and how old, it’s just sort of fascinating to think that it’d work just as well at, say, Tau Ceti as it would here, and you could even use the same starcharts.
See "First Lensman" by E.E. "Doc" Smith, in which Virgil Samms uses his knowledge of star patterns to roughly locate the position of a drug syndicate's drop station for future detailed reconnaissance. The payoff comes when they detect a signal coming from that direction and have a fair idea of what its significance is.
With the astonomican and my trusty gellar field, we have no need to fear the dangers of space. Of course, I do not fear at all, having partitioned my unnecessary emotions apart from my cognitive functions. Praise the Omnisiah. 🙏
Ooh, this certainly does give me inspiration! In my setting, the protagonists start in a single solar system that doesn't have interstellar travel-well, until the events of the story come along. It would make sense if they mostly used a solar system map & GPS to navigate, and so when the protagonists are stranded in another star system, they would have to learn how to navigate without either method. 🤔
I remember the Star Trek TOS Technical Manual had a page that summed up how they handled course tracking, with the computer integrating a SINS platform, several elements of what would be needed for dead reckoning(engine output, records, helm response, etc), as well as external systems including the various scanners, a telescope, and a "civil spaceways beam rider" which I'm guessing would be a type of space-GPS system from before we had a term for that.
I think it was Wing Commander when I first heard of pulsar navigation. Nice tie to submarines and inertial navigation, a technology that is still critical and evolving.
You forgot the real problem: knowing where "you" are and knowing your vector is just one part of the equation of star navigation. The next step is knowing where your target will be. You see a picture of the past (which is only problematic for longer distances) and the target, where you want to be, moves in a 4D space. Additionally, you need to know the way, including sling shot maneuvers, gravitational forces, and fuel economy.
With pulsar navigation, you would also need a spin-down model to figure out if the your relative instantaneous speed. Pulsars slowly change their pulsation speed as their spin slows down. How fast you are going will also change the the apparent pulse rate. Triangulation between pulsars isn't good enough to narrow down your position if you don't know how the light cone from those pulsars are warped because of your relativistic speed. To compensate for that distortion, a good model of the pulsars' ring-down would be needed and compared to known pulsation from a known distance, time and relative speed. The larger the percentage the speed of light you are traveling, the more important this discrepancy becomes, getting very bad at FTL speeds.
One issue with using pulsars for navigation, is they rely on the orientation of the pulsars beam crossing relatively close to you. If you moved significantly far (say the other side of the galaxy), the odds the pulsars sweep planes still cross your point in the same way is unlikely, unless they were extra galactic pulsars. (which may be fairly common.. can't remember how well we can see extra galactic pulsars, my brain is mixing them with quasars a bit)
I just wanted to say that your videos have really helped me out with my full-time work modeling spacecraft and my own channel during 2023. Thank you for your videos.
presumably very much yes. you can however do observations, and if you're not worried about making noise, you could use radio-lighthouses to create navigation signals set up so you can tell where you are by which part of the signal was sent when
With respect to system or planetary surveys in science fiction, I cannot recall if a story used ship-centric "GPS". The survey ship would be the reference point, then deploy micro-satellites to generate a temporary base map of a planet or system. As the survey obtains more information, the temporary base map would be discarded for the completed survey map.
1:10 reminds me of a line from the book "The Martian": (Spoilers, I guess?) When making his way from the Hab to the ARES-IV launch site Mark Watney also uses a sextant for navigation. In his log he makes a joke something like, "It's quite funny, I'm standing here on the surface of mars, wearing a high-tech spacesuit. But I'm navigating using 16th-century tools." NOTE: In the book, when preparing for the journey, Watney messes up and destroys pathfinder (which he has been using as his make-shift radio transmitter), therefore NASA can't tell him his location.
GPS is even cooler because the satellites don't just have to account for the light speed delay But also the relativistic effects of time dilation because they move so fast around the earth. If they kept normal earth time the calculated position would drift by miles
"Pilgrims were the first space explorers and sailors. For five centuries they defied the odds. They embraced space, and for that, they were rewarded with a flawless sense of direction. They could feel magnetic fields created by quasars and black holes, negotiate singularities, navigate not just the stars, but space-time itself. "
If you are using a sextant and clock to travel between stars, also consider that relativity has time and space dilating as an object approaches the speed of light, which could throw off your calculations for where your destination will be by the time you get there
For sextant navigation you could create an atlas book of different star maps! Every page could be a different star maps from the perspective of another star, and they could all be calculated by a single astronomer anywhere in the galaxy prior to a starship's voyage. They could even calculate the star maps for unexplored stars too! As long as they can see it in their telescope, they can map it.
On the softer sci-fi side of things: what if you're in a dust cloud or void or some kind of anomaly, could anything get through? Would you be restricted to particular signals? Could you use variations in CMBR, which is supposed to look mostly the same everywhere? Gravity wave stick charts?
Navigation through the stars would be quite difficult. Light takes time to travel, so the stars aren’t even actually where they appear to be. The view we get of them is from where they were in the past. Meaning you have to predict where they’re headed, and used that prediction in relation to their distance to get a rough idea of where the star is now. While we can predict the movement of these objects, much like the predictions on hurricane movement, that becomes less certain over larger distances. Interference from other objects could make that course deviate in ways you couldn’t predict. For example, let’s say there’s a blue shifted star, and through all the observations you’ve seen, it appears to be moving toward you. You set a course, but when you get there, oops. There was a black hole no one detected, and the star was orbiting that. While it was headed for you at one time, thanks to that orbit, it has now deviated away from your original intercept point. It’s apparent motion may not look very big, but it is now somewhere completely different. Plus, all the stars around you have not changed their positions as well. You are now lost.
The fun thing about my world is that, when traveling at FTL speeds by any speed, you inherently have to fly blind. This is to resolve certain paradoxes which can be caused by sending communications at superluminal speeds, for the sake of my peace of mind and for making my story world more interesting. Anyway so this is specifically a challenge when using an Alcubierre-style warp drive like humans do in this world, because the ship is not tethered to a hyperlane or pre-bored wormhole. So to even keep their ships pointed in the right direction, humans have built some of the most advanced supercomputers in the history of the galaxy just for basic civilian use. These computers are called Laplace's Demon Modules (LDMs). The LDM does extremely precise calculations based on the ship's initial velocity, initial heading, expected trajectory, acceleration, and any slight bumps it may feel along the journey. The LDM is also hooked up to the most up-to-date possible forecasts of interstellar dust, asteroids, and rogue planets, whose gravity wells could slightly alter the path of the ship during a jump. The Warp Drive itself is in the form of a ring rotating at several thousand RPM, and to send information to the components in the ring, rather than using wire up from the center, a Timing Bar is used which sends signals through light to remove as much latency as possible, keeping the Drive moving at as precise of a heading as possible. Finally, when the destination system is reached, the ship drops to subluminal speeds at least one full minute before expected arrival time so the LDM can reposition itself. On long journeys, warp drive-equipped ships make several stops along the way, because if the ship is flying blind for too long it will eventually veer off-course. I guess it's just a lesson that taking in realistic concepts into even really soft sci-fi (my world ain't exactly the Expanse) can open up really cool worldbuilding ideas.
Will admit I fojdn this especially interesting since I am trying to work out my own sci-fi setting, snd navigation being a big aspect since thr ship found herself in another galaxy without good charts. Now of we can get a video on radiation shielding
Space navigation is a awkward concept, but the technology they use is no different that what we actually use. The "Inertial Navigation System" operates by use motion and rotation gyroscopes and sensors thus it can determines position, orientation, and speed of the vehicle without using the stars, Sun, Moon, planets or some outside visual reference. This was used by Apollo program to create a computer controlled navigation system. Another method is use of X-ray/Gamma pulsars which permeate across the galaxy, the hyper bright burst of quasars. These objects remain fairly static and their pulse frequency is an ideal method to compare various distances.
Internal errors are not the reason you can't rely only on inertial sensors. The problem with inertial sensors is that they can be fooled by gravity. By that I mean they will fail to detect gravity when installed on a spacecraft that is being pulled by the same gravitational field. In order to have accurate dead reckoning it is necessary to account for any perturbations. The inertial sensors can only detect thrust and non-gravitational perturbations, like solar pressure.
Well, it's more like internal errors aren't the _only_ problem with inertial sensors. Gravitational effects are just another. The cumulative error problem is still very real, and is why real-world systems uses various methods of correcting inertial navigation systems. I don't think gravitational effects apply that much here on Earth (since there is little gravitational variation), but inertial navigation is still not seen as very reliable without having error corrections applied constantly.
@@mnxs agreed. Inertial sensors really work well for a short period time but errors stack over time. There are ways to account for drift, but the best practice is to take new sightings to reset the error.
@@circuitboardsushi Indeed. I was personally thinking of aircraft. They also use inertial navigation systems as a baseline and backup, but they do get out of sync in the course of hours of flight, and so they're corrected with GPS.
The end result of this series of sci-fi mechanics and science had better be an announcement that Space Dock has constructed its own space battleship and will soon be casting off from a secret construction station in the lunar shadow to conquer the solar system then the galaxy in the name of all the nerds and sci-fi enthusiasts of Earth!
4:47: 3 billion stars. That's not sci-fy anymore. The Gaia probe has already measured almost as many objects. For almost one billions stars it got the position, speed, heading, color, magnitude. We can visualize our neighborhood pretty accurate and could also calculate our position. Well... if we could travel this far. But even a billion stars isn't much. It's just 1% of the galaxy. There are some neat visualizations out there showing the stars based on that real data. And we didn't even use Borg tech.
I would expect a populated space with established travel routes would also use some form of beacon, much like the beacons used in early transcontinental air travel. for a planet, there would be a geostationary beacon "ahead" and "behind" it in orbit, for a star system, one beacon would be enough for interstellar FTL travel, because it wouldn't move enough in the travel time to require plotting an intercept.
It’s pretty crazy how all the tools we need to survive in space are there. We just have to figure out what they are and how to use and understand them. I like to believe that if we weren’t supposed to be out in space we wouldn’t be able to even leave earth in the first place. I think of Earth as tutorial island at the beginning of a game. We have to learn as much as we can down here so that way we can apply all of that out there. It’s forgiving here on earth to some degree (please don’t burn me at the stake for saying that, these are just my observations) But out there it’ll require a lot of team work. There wouldn’t be room for prejudices or petty grievances. The bigger picture would have to be the mission. A future for all generations to come. Just like the sacrifices people made before our time. The hope for a better life for those that come after.
The spacecraft knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the spacecraft from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't. In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the spacecraft is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the spacecraft must also know where it was. The spacecraft guidance computer scenario works as follows. Because a variation has modified some of the information the spacecraft has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error.
Hi Spacedock. Could you do a video on a possibility of a real world Homeworld type ship. So is it possible create a mothership that is entirely self sufficient and could be park next to an asteroid belt and mine and build fleets of new ships. The mothership wouldn't have access to a planet so it would need to be built to house anything it would need. mining facilities. refineries/ manufacturing, you would also need to support the crew so you would need on board farms and food processing.
My own StarWars headcanon: Astromech droids are startrackers, using the stars to determine their EXACT location. Instead of a simple catalog, they use a map of the ENTIRE galaxy!... or as much of the galaxy as has been reliably mapped, anyway.
Speaking of navigating. I’m kinda wonder how many ship’s helmsman in sci fi able to pull off an extreme maneuver with just a touch screen? I mean, think about those USS Enterprise E conn and the Expanse iPad like thingy that the pilot uses, it looks rather hard to use that to control a massive aircraft given how cumbersome they would be.
In a story I'm working on the way the characters find out where they are in the galaxy is by which ring they are in, out of nine and going out from the core, and then by use of six pulsars that can be seen.
What if, instead of using nearby stars that are visible with current technology, interstellar travel made use of powerful telescopes that could resolve individual stars in distant galaxies, making their positions relatively the same for all nearby star systems.
In the sci-fi I'm writing, a lot of terms are absolutely arbitrary. Like the "north" of a solar system is determined by the poles of the primary, and the plane of the ecliptic when (most) planets are orbiting counter-clockwise, and headings are based on an angle between the bow and the primary, with the primary always being 0.
I liked how in Lost Fleet series they used good old "port/starboard" for directions - but instead of our arbitrary "left/right" it meant that "starboard" was literally "towards the star". So at any location of any star system you could easily issue directions to your fleet no matter how each ship was oriented in the 3d space
what about the newest real life gravity wave detectors that bsacly use lasers via gravty wave vidrations to bascly when disurbed by the menuite difreaces of the lasers pathways caused by gravty waves intracting with the laser beams can be bascly used to detect and navgate in deep space. also they can also detect thsoe gosh darn alein gravity wave ftl drives realy easly too by the way if you got enotgh of them to trangalte where they are bascly.
a) Gravity wave detectors are HUGE. And ridiculously sensitive bits of kit. (They can pick up your footsteps from KM away, sensitive.) b) GRavity waves are not regular, repeated events as a rule.
In the Expeditionary Force series Book 1 "Columbus Day", Human Soldiers were taken to train on Alien Weapons on another planet and they brought astronomers with them to figure out where they were in the galaxy by looking for stars they knew their characteristics.
Can you do a video on galactic mapping with sci fi cultures that have FTL. The first issue I see is that because the ships move much faster than light in these settings, which means maps need to account position and distance to determine where a Star should be via FTL, rather than the light that would be showing the stars past position.
This is a topic i have always wondered.... But Interstellar travel. WHere the travel time is so long, that the destination stars movement have to be counted accurately, or you miss your target... Not just point at it, To sirius, just point at it and you head for the location where it was 8.7 years ago. You have to count its present speed and heading.
Another example of building a star map, albeit less realistic, is seen in E.E. "Doc" Smith's Skylark of Valeron, in which the heroes have been displaced so far from home they literally don't know where they are in the universe. Their saving grace is the incredibly detailed star map that was produced by the genocidal race they'd recently just finished exterminating. In order to get home, they have to build a ship/observatory with graduated circles a thousand kilometres in diameter with which to map the entire universe to the required precision. It takes a while before the map they've built matches up to the map they've got.
I design underwater systems and its like this apart from there's no visibility, no RF signals and you get pushed around more 😂 Space would be massively easier!
Are there any spectra from pulsars that could be used to fingerprint each one? Such that if you were traveling faster than like, you could work out which one is which and therefore use that to determine your location? It seems to be that other otherwise for fashion light travel the only alternative is for artificial intelligenceto know the locations of the various pulsars and extrapolate the possible combinations based on their positions and movement although with Fast and light travel, they’re movement relative to each other would make a larger difference depending on how time was dilated.
Accurate time is very important to GPS calculations. Due to gravitational effects clocks in orbit actually run 45 millionths of a second faster than they do on Earth's surface. So, Earth bound clocks have to add that into their calculation. This can be a problem where the gravitational field varies. Say where the mass density of the Earth is higher or in places where space-time seems to be disturbed (cough: Skinwalker Ranch). Anything that disturbs gravity thus altering the flow of time can throw off GPS. It's not very useful around a blackhole.
I like the idea of your average star-hopping, rag-tag smuggler in a sci-fi setting actually being really good at calculus, because you would have to be in order to make a living in space.
Or they have a computer
@ksevio But that's the thing. If the computer fails, you either have to know how to fix it or do the calculations yourself. Both of which are equally funny to think about.
Texas instrument
@@tunguska2370 yes I got a Ti 83. as long as it gets fresh batteries. it takes almost anything.
That is not likely, as the math required for maximizing dV efficiency will be phenomenally complex, thus requiring computers.
People forget that Apollo's computers weren't the main computers; they were there just for 'that final mile,' so to speak. The real computers of Apollo were massive mainframes at NASA that sent data to Apollo.
While we've got computers now that can do what those mainframes did _on_ the spacecraft, we're getting to the point where we'll need pretty chunky computers to maximize dV efficiency. At least until we get CG-NTRs (Closed-Gas Nuclear Thermal Rockets, aka 'nuclear lightbulbs') using water up and running.
Han Solo being a disguised super-nerd is quite the funny thought.
I'm pretty sure it's Chewie who handles the math-y stuff. (Though you're right, I imagine han prefers to be able to keep the falcon's tech maintained himself, so he's probably pretty knowledgeable about the machinery)
It's not nerdy when it's a practical skill used to get a useful job done;).
Han Solo is using a droid brain trapped in his ship to navigate for him.
- hoojiwana from Spacedock
@@hoojiwana However as another person has said, he still has to maintain the machinery. And, correct me if I am wrong, but there have been several points in time when he wasn't accompanied by an astromech. Though I am not the most knowledgeable on star wars so if you are talking about an actual computer in the falcon then I retract my statement.
@@hoojiwana and not forget that there is the whole Astromech Droid Class for that task and L3-37 was one
"Wheel, telescope, astrolabe, compass: a ship's a ship"
- Doctor Who, 'Curse of the Black Spot'
Astronauts on Apollo used an advanced Astrolabe to navigate
"... a tall ship, and a star to sail her by".
"John Masefield"
@@3Rayfire Are you sure about that?
@@CathrineMacNiel I am well versed in the classics doctor.
@@3Rayfire Then how come you didn't know Row row row your boat? >:(
@@CathrineMacNiel 🙄
One more thing about FTL-capable civilizations is that, when you warp/hop to another point in space, you are seeing starlight, their redshift, and positions, at vastly different points in time. Say, our map of Proxima Centauri's position today, in Earth's inertial frame, is its position 4.2 years ago. And that's the second closest star to us.
very old stars and exogalactic objects like other galaxies and super-stars etc. are already in use for stellar observations and figuring out where things are. anything outside the galaxy should make for a useful reference point in a pinch, if you don't have local starmaps and whatever you use during FTL for navigation (if thats a thing for your FTL system)
Big oof. Not only do you have to calculate position by how many reference points, you have to factor in light delay with each one being it's own variable.
Which means you also have to track "when" you are, and "when" you left as well, and of course the faster you go the more varied that can be, as well as passing closer or farther to gravity wells.
And as @Edge-wx7hv points out, you might use other galaxies and super-stars for farther reference points, but if you make a blind jump, or get sent somewhere way far off from where you expect to be, or beyond your frames of reference, you might well have no way to tell "where" or "when" you are.
Though that last situation is probably a pretty far out outlier. And if we're in a situation where we wind up in a different corner of the universe, we've either got that solved, or we've got way bigger problems.
This is a concept that I love about Sci-fi. @@tearstoneactual9773
And then you have to account for stellar drift or end up popping out of FTL in the middle of nowhere.
I love that you are making a few videos on a bit more of the practical matters of spaceflight. In my studies as a civilian mariner we where taught that gps simply works by caculating our distance to any gps satelite. If you have the exact distance to a minimum of three satelites, you know exactly where you are. The distance is calculated by measuring the time it took the signal to reach the vessel ( usually down to a fraction of a mili-second), As Distance= Speed* time traveled, and we know speed and time, this isn't that hard for a computer.
It's a bit trickier than that. First of all, the measurement precision of the time-delay before reaching the vessel is _much_ higher than merely fractions of _milliseconds_ - remember, a "light-nanosecond" is about 1 feet/30 cms. Modern GNSS systems (like GPS) can achieve precision on the order of a few _centimeters_. In other words, you need nanosecond to sub-nanosecond precision to achieve achieve modern accuracy.
Secondly, the math involved is far more complicated than merely calculating distances; this has to do with orbital mechanics and even the time-dilation factors from special relativity, as I understand it. (But I'm hardly an expert though, so take this with a grain of salt.)
@@mnxs yeah something like that. Im no expert either, I just use the stuff, I don't build them.
You can go a level above and use quasars for extra-galactic (maybe out to order 0.1-1B LY) navigation in a similar manner to pulsars as the ~200 brightest have well defined absolute brightness and distance. These quasars are also incidentally, the reference points the GPS satellites use to estabilish their own location as they are far more fixed in space from our perspective than the sun is relative to stuff like pulsars or bright local stars.
Do you know what would be interesting? A combination between using Quasars and Pulsars within a galaxy.
Since Quasars are functionally stationary in the night sky, you can use them like a North Star of sorts, with the Pulsars giving a secondary set of coordinates.
@@VelociraptorsOfSkyrim It turns out that pulsars are basically useless in terms of interstellar navigation because the beams they put out are narrow. Even as close as Alpha Centauri you could potentially be out of the beam path of many of the pulsars in an earth-centric database. The location plaques on the space probes mentioned in the video will be completely useless if some other civilization finds them, because they won't be able to see the pulsars used as beacons. Later probes used globular clusters as signposts because they can be seen from any angle.
@@willythemailboy2 That is an unfortunate pickle.
Quasars and Globular Clusters, then?
Well you could use [insert information to contribute here] and [insert follow up information here] that way you get around that problem 😊
In one of the later Foundation books, the main character insists on making the hyperspace jump calculations himself (which can take hours or even days) because he doesn't trust the ship's newfangled "com-pyoo-ter" to do it properly.
Now I'm reminded of the "Jumpships" in Battletech, and how they can calculate their FTL jumps with a Human or computer. Said Jumps are limited to 30ly at a time, it takes a week to recharge between jumps, but can be accurate to a few Kilometers. The lore blurb in the "Strategic Operations" Rulebook also mentions how very bad navigators can sometimes "misjump" and find themselves several light-years away from their intended location. Said Jumpships usually find themselves with an open Navigator position shortly thereafter 😂
In Star Wars lore, astronavigation information was regularly updated via the holonet. It seems the Empire could have effectively controlled who could travel where by cutting off updates.
The Star Wars galaxy being a flat disc simplifies things there.
The Empire didn't control the Astronavigation update system.
The neutrality of the guilds responsible for it has been paramount to their business since before The Republic was a thing.
@@CantankerousDaveit's only a flat disc in artistic representations in soyrce books because pages in books are flat, in-universe it's as 3D as it should be.
That may explain why about half the Star Wars galaxy is marked here be dragons. The Empire doesn't want people to know what's out there. Or Abeloth?
I worked on a sci-fi world where the main form of FTL navigation was based on measuring pulsars. The navigational computer held a large darabase of pulsars and large stars with information to calculate changes based on age. Naturally FTL would mean the signals from the same pulsar were not the same 1000 and 8000 lightyears from it.
Navigational accurace was based on how accurate your pulsar database was.
However a small angular difference and any gravitational interference would change your trajectory. To nerf FTL but allow for it as a story element travel required a lot of shorter jumps. Constant readings confirmed the accuracy of the navigational system and the computer automatically adjusted jump direction based on it. This was the way to allow FTL travel even for damaged ships.
And traveling to other galaxies required getting the appropriate pulsar and system maps.
Did it account for doppler shift/light delay? Your point of observation changing would change how "old" the light from your points of reference would be, so you'd be seeing where it "was" not where it "is" now.
It turns out that pulsars are basically useless in terms of interstellar navigation because the beams they put out are narrow. Even as close as Alpha Centauri you could potentially be out of the beam path of many of the pulsars in an earth-centric database. The location plaques on the space probes mentioned in the video will be completely useless if some other civilization finds them, because they won't be able to see the pulsars used as beacons. Later probes used globular clusters as signposts because they can be seen from any angle.
Quasars would work within a fairly big radius, though.
The missile knows where it is at all times. It knows this because it knows where it isn't, by subtracting where it is, from where it isn't, or where it isn't, from where it is, whichever is greater, it obtains a difference, or deviation. The guidance sub-system uses deviations to generate corrective commands to drive the missile from a position where it is, to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position where it was, is now the position that it isn't. In the event of the position that it is in is not the position that it wasn't, the system has required a variation. The variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too, may be corrected by the GEA. However, the missile must also know where it was. The missile guidance computance scenario works as follows: Because a variation has modified some of the information the missile has obtained, it is not sure just where it is, however it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be, from where it wasn't, or vice versa. By differentiating this from the algebraic sum of where it shouldn't be, and where it was. It is able to obtain a deviation, and a variation, which is called "error"
I need to ask, how difficult was it to type this all up? Good job at any rate!
@@LilFeralGangrel I just found a copypasta of it and fixed the errors that's all
I've seen this exact comment before .
This never gets old, but what is the origin of the text? Does anyone know?
You are so creative and smart, I have never seen this before!
I'm currently reading the Frontlines series by Marko Kloos. "Orders of Battle" has the main character's ship sucked into an Alcubierre bubble, where FTL is capable. In human vessels, the farther the system from the entry node, the longer the transit. When drafted along by the alien vessel, they go farther than ever before, and with the shortest transit time they'd seen.
For example, the 150 light year transit requires a full 24 hours in Alcubierre. But the alien bubble takes them 900 light years, over a mere 33 minutes.
When they determine their position, they use what is referred to as Galactic Positioning, which uses known pulsars as points of reference. The fine points are not addressed, but they determine themselves to be 900LY from Earth space.
That’s a great series. Read all 8 books in like a 3 month span
Never read the book I'll look it up. Does the alien bobble in theory work the same as warp bobble? The way you deceive it seems like it.
A realistic star tracking system on a galactic scale would need significant computational power, I think, in order to calculate the movement of individual stars from the positions listed in the ephemeris.
Another factor is navigating while travelling at relativistic velocities; you have to deal with non-simultaneous, non-causally-linked events being ordered arbitrarily. You also would have to deal with the fact that new stars are born and old stars die; stars which are in the catalogue might not be around any more, and stars which meet all the criteria for being in the catalogue might not be in them, because they were born after the last update of the catalogue.
For solar system nav, I can see us setting up solar system GPS satellites/beacons in lagrange points of each of the planets, just doing the same type of GPS calculations we do now with satellites around our planet, just on a much bigger scale, and it can be just as accurate, and will move with the planets as they move.
For interstellar nav, the only real feasible method has got to be Pulsar nav. Those things are very regular and "reliable", and can get you reliably to another star system, or space based installation close enough to use transmitted beacons from the remote system or installation you are approaching, kind of like a layered series of systems.
Serious fast nav computing with multiple redundant backup nav computers checking and cross-checking each other would be essential for doing all of this.
This is really interesting for a video topic - Thanks for this!
fun fact i had a lecture from the person who discovered pulsars today. i wish i saw this video first so i could of asked about if she thought of or heard of the navigation use. her name is Dame Jocelyn Bell Burnell if anyone is wondering.
About time she got a title for her work.
The phrase "Borg know-how" conjures the image of a gruff yet reliable cyborb tradesperson in overalls.
I think a great foundation for this subject is Dava Sobel's "Longitude", an essay about how difficult it was to calculate your position at sea during the age of sail.
Hey, I just thought of the reference-star navigation idea myself, mostly because in Starfield Cora Coe keeps saying, "on Earth people used the stars to navigate, but that doesn't work in space" even though in Space there's... pretty much nothing else to use to navigate.
Oh dear, its very possible to navigate using the stars, what else would you use!
- hoojiwana from Spacedock
Yet another Starfield fail. Bethesda has fallen so far.
GPS is indeed a very clever and accurate form of military navigation that Reagan released to the public after the Korean Air 007 was shot down by the USSR in the early 80's after it strayed into Soviet air space. I was a young child at the time, but flew on that same Boeing 747 KAL-007 on the same route a year prior.
It was really more of a PR move by Reagan to "release it" - this was before the system was operational, and it was _already known_ that the public would be given access to the CA component of the GPS signal (Coarse/Acquisition); this meant only having precision down to, on average, 100 meters.
It was really moreso Clinton who released it such that it took the form - ie., accuracy - that we've become familiar with, by removing the scrambling of the until then military-only component of the signal. And even then this was because of not only high civilian demand, but also that various augmentation schemes with fixed terrestrial transmitters was in use already (thus making the scrambling obsolete), plus that the US military was actively developing ways of jamming the signal to prevent it being used offensively by others.
A cool tracking system that was used in the book series "looking slass" by John Ringo wich used cameras located across the entire ship and mouse image movement tracking software to build a location map and track the ships movement across space
IIRC, Harry Turtledove's short story "The Road Not Taken" offers a unique scenario, where alien species with bronze-age-to-medieval technology also have FTL and gravity manipulation. Humanity is exceptional in having completely overlooked the very simple physical effect by which aliens traverse the stars. It's tangential to the story, but the fact that these otherwise primitive aliens navigate across light years by dead reckoning and memory of major stars-no math or computers involved, I don't even recall if they had drawn charts-was a fascinating detail in that unique story universe.
If I recall correctly, given how far away, the stars are from here, pretty much any solar system within about 13 ly of earth is going to have essentially the same constellations. Some individual stars may be a little brighter or a little bit dimmer, but their sky is basically the same same as our sky. And again, if I recall correctly, you can ghetto out about as far as 35 ly and still recognize the same constellations we see from here. They will be somewhat deformed compared to what they look like in the night sky, butmstill fairly recognizable
Yep, but think how many franchises have you going all over the galaxy, and not just pottling about the local neighbourhood!
- hoojiwana from Spacedock
@@hoojiwana oh, I know. To be honest, I’m not sure why I posted that, other than I thought it was interesting. Given how low tech a sextant is, and how old, it’s just sort of fascinating to think that it’d work just as well at, say, Tau Ceti as it would here, and you could even use the same starcharts.
See "First Lensman" by E.E. "Doc" Smith, in which Virgil Samms uses his knowledge of star patterns to roughly locate the position of a drug syndicate's drop station for future detailed reconnaissance. The payoff comes when they detect a signal coming from that direction and have a fair idea of what its significance is.
All I need is the light of the astronomican. Bless the emperor 🙏
Gloria in Excelsis Terra.
With the astonomican and my trusty gellar field, we have no need to fear the dangers of space. Of course, I do not fear at all, having partitioned my unnecessary emotions apart from my cognitive functions. Praise the Omnisiah. 🙏
"Bröther, I crave lamp!"
-several hive fleets
Ooh, this certainly does give me inspiration! In my setting, the protagonists start in a single solar system that doesn't have interstellar travel-well, until the events of the story come along.
It would make sense if they mostly used a solar system map & GPS to navigate, and so when the protagonists are stranded in another star system, they would have to learn how to navigate without either method. 🤔
I remember the Star Trek TOS Technical Manual had a page that summed up how they handled course tracking, with the computer integrating a SINS platform, several elements of what would be needed for dead reckoning(engine output, records, helm response, etc), as well as external systems including the various scanners, a telescope, and a "civil spaceways beam rider" which I'm guessing would be a type of space-GPS system from before we had a term for that.
The falcon has a spirit of rebellion that calculates all the nav math
I think it was Wing Commander when I first heard of pulsar navigation. Nice tie to submarines and inertial navigation, a technology that is still critical and evolving.
You forgot the real problem: knowing where "you" are and knowing your vector is just one part of the equation of star navigation. The next step is knowing where your target will be. You see a picture of the past (which is only problematic for longer distances) and the target, where you want to be, moves in a 4D space. Additionally, you need to know the way, including sling shot maneuvers, gravitational forces, and fuel economy.
Kind of like the idea some type of deep space stations that release gps like signals to help a ship navigating the void between star systems
One of my favorite examples of celestial navigation is from Avengers 2012:
"Is the Sun coming up?"
"Yes."
"Then put it on the left."
With pulsar navigation, you would also need a spin-down model to figure out if the your relative instantaneous speed.
Pulsars slowly change their pulsation speed as their spin slows down. How fast you are going will also change the the apparent pulse rate. Triangulation between pulsars isn't good enough to narrow down your position if you don't know how the light cone from those pulsars are warped because of your relativistic speed. To compensate for that distortion, a good model of the pulsars' ring-down would be needed and compared to known pulsation from a known distance, time and relative speed.
The larger the percentage the speed of light you are traveling, the more important this discrepancy becomes, getting very bad at FTL speeds.
One issue with using pulsars for navigation, is they rely on the orientation of the pulsars beam crossing relatively close to you. If you moved significantly far (say the other side of the galaxy), the odds the pulsars sweep planes still cross your point in the same way is unlikely, unless they were extra galactic pulsars. (which may be fairly common.. can't remember how well we can see extra galactic pulsars, my brain is mixing them with quasars a bit)
I just wanted to say that your videos have really helped me out with my full-time work modeling spacecraft and my own channel during 2023. Thank you for your videos.
Wow that's is one really great episode let's have more
Still using that space engineers music sound track? Nice 😎
Wouldn´t navigation in FTL be kind of strange. As youl catch up old signals from places behind you.
presumably very much yes. you can however do observations, and if you're not worried about making noise, you could use radio-lighthouses to create navigation signals set up so you can tell where you are by which part of the signal was sent when
You'd presumably need to just travel in straight lines, for a set period of time.
Space navigation sounds like a pretty cool occupation
Thank you for mentioning 4D! As a physicist, I love your videos, thank you!
One of your better videos - practical and grounded appropriately in some good real science.
With respect to system or planetary surveys in science fiction, I cannot recall if a story used ship-centric "GPS". The survey ship would be the reference point, then deploy micro-satellites to generate a temporary base map of a planet or system. As the survey obtains more information, the temporary base map would be discarded for the completed survey map.
Interesting that this comes up on the same day I've been watching about real world problems in GPS spoofing in Commercial flight
1:10 reminds me of a line from the book "The Martian": (Spoilers, I guess?)
When making his way from the Hab to the ARES-IV launch site Mark Watney also uses a sextant for navigation. In his log he makes a joke something like, "It's quite funny, I'm standing here on the surface of mars, wearing a high-tech spacesuit. But I'm navigating using 16th-century tools."
NOTE: In the book, when preparing for the journey, Watney messes up and destroys pathfinder (which he has been using as his make-shift radio transmitter), therefore NASA can't tell him his location.
GPS is even cooler because the satellites don't just have to account for the light speed delay But also the relativistic effects of time dilation because they move so fast around the earth. If they kept normal earth time the calculated position would drift by miles
I love how many footage of shows you use , great ones to see in the future
Thank you for pointing out that everything is in motion.
"Pilgrims were the first space explorers and sailors. For five centuries they defied the odds. They embraced space, and for that, they were rewarded with a flawless sense of direction. They could feel magnetic fields created by quasars and black holes, negotiate singularities, navigate not just the stars, but space-time itself. "
If you are using a sextant and clock to travel between stars, also consider that relativity has time and space dilating as an object approaches the speed of light, which could throw off your calculations for where your destination will be by the time you get there
This topic suprisingly made me a lot more interested.
There is an often overlooked aspect of traveling at relativistic speed. The ginormous future cone.
For sextant navigation you could create an atlas book of different star maps! Every page could be a different star maps from the perspective of another star, and they could all be calculated by a single astronomer anywhere in the galaxy prior to a starship's voyage. They could even calculate the star maps for unexplored stars too! As long as they can see it in their telescope, they can map it.
On the softer sci-fi side of things: what if you're in a dust cloud or void or some kind of anomaly, could anything get through? Would you be restricted to particular signals? Could you use variations in CMBR, which is supposed to look mostly the same everywhere? Gravity wave stick charts?
Navigation through the stars would be quite difficult. Light takes time to travel, so the stars aren’t even actually where they appear to be. The view we get of them is from where they were in the past. Meaning you have to predict where they’re headed, and used that prediction in relation to their distance to get a rough idea of where the star is now. While we can predict the movement of these objects, much like the predictions on hurricane movement, that becomes less certain over larger distances. Interference from other objects could make that course deviate in ways you couldn’t predict.
For example, let’s say there’s a blue shifted star, and through all the observations you’ve seen, it appears to be moving toward you. You set a course, but when you get there, oops. There was a black hole no one detected, and the star was orbiting that. While it was headed for you at one time, thanks to that orbit, it has now deviated away from your original intercept point. It’s apparent motion may not look very big, but it is now somewhere completely different. Plus, all the stars around you have not changed their positions as well. You are now lost.
The fun thing about my world is that, when traveling at FTL speeds by any speed, you inherently have to fly blind. This is to resolve certain paradoxes which can be caused by sending communications at superluminal speeds, for the sake of my peace of mind and for making my story world more interesting. Anyway so this is specifically a challenge when using an Alcubierre-style warp drive like humans do in this world, because the ship is not tethered to a hyperlane or pre-bored wormhole. So to even keep their ships pointed in the right direction, humans have built some of the most advanced supercomputers in the history of the galaxy just for basic civilian use. These computers are called Laplace's Demon Modules (LDMs). The LDM does extremely precise calculations based on the ship's initial velocity, initial heading, expected trajectory, acceleration, and any slight bumps it may feel along the journey. The LDM is also hooked up to the most up-to-date possible forecasts of interstellar dust, asteroids, and rogue planets, whose gravity wells could slightly alter the path of the ship during a jump. The Warp Drive itself is in the form of a ring rotating at several thousand RPM, and to send information to the components in the ring, rather than using wire up from the center, a Timing Bar is used which sends signals through light to remove as much latency as possible, keeping the Drive moving at as precise of a heading as possible. Finally, when the destination system is reached, the ship drops to subluminal speeds at least one full minute before expected arrival time so the LDM can reposition itself. On long journeys, warp drive-equipped ships make several stops along the way, because if the ship is flying blind for too long it will eventually veer off-course. I guess it's just a lesson that taking in realistic concepts into even really soft sci-fi (my world ain't exactly the Expanse) can open up really cool worldbuilding ideas.
5:02 That episode of Sliders was one my favorites.
Will admit I fojdn this especially interesting since I am trying to work out my own sci-fi setting, snd navigation being a big aspect since thr ship found herself in another galaxy without good charts.
Now of we can get a video on radiation shielding
Space navigation is a awkward concept, but the technology they use is no different that what we actually use. The "Inertial Navigation System" operates by use motion and rotation gyroscopes and sensors thus it can determines position, orientation, and speed of the vehicle without using the stars, Sun, Moon, planets or some outside visual reference. This was used by Apollo program to create a computer controlled navigation system.
Another method is use of X-ray/Gamma pulsars which permeate across the galaxy, the hyper bright burst of quasars. These objects remain fairly static and their pulse frequency is an ideal method to compare various distances.
Internal errors are not the reason you can't rely only on inertial sensors. The problem with inertial sensors is that they can be fooled by gravity. By that I mean they will fail to detect gravity when installed on a spacecraft that is being pulled by the same gravitational field. In order to have accurate dead reckoning it is necessary to account for any perturbations. The inertial sensors can only detect thrust and non-gravitational perturbations, like solar pressure.
Well, it's more like internal errors aren't the _only_ problem with inertial sensors. Gravitational effects are just another. The cumulative error problem is still very real, and is why real-world systems uses various methods of correcting inertial navigation systems.
I don't think gravitational effects apply that much here on Earth (since there is little gravitational variation), but inertial navigation is still not seen as very reliable without having error corrections applied constantly.
@@mnxs agreed. Inertial sensors really work well for a short period time but errors stack over time. There are ways to account for drift, but the best practice is to take new sightings to reset the error.
@@circuitboardsushi Indeed. I was personally thinking of aircraft. They also use inertial navigation systems as a baseline and backup, but they do get out of sync in the course of hours of flight, and so they're corrected with GPS.
Loving the Space Engineers background music
Even in the Military we say Lost = Dead.
That statement is never truer than out in space.
I just blind jump/warp and rely on plot armor to not smack into planets at warp 7. It's worked so far.
Much inspirational indeed. Thank you !
Excellent discussion.
I love the idea of galactronaughts using aol CD's to make the adtrogation navigation
The end result of this series of sci-fi mechanics and science had better be an announcement that Space Dock has constructed its own space battleship and will soon be casting off from a secret construction station in the lunar shadow to conquer the solar system then the galaxy in the name of all the nerds and sci-fi enthusiasts of Earth!
My ways of space travel are called "fuck it we ball" and "I fucking guessed"
My solution was using "navigators" telepaths who can detect and map out the surroundings when they're in a sense deprivation type of tank.
Do they like "spicy" food?
@@TotallyNotAFox Yes. But they have to be melange free, tho. ;)
Do they by chance need a "lighthouse" powered by an immense amount of human sacrifice?
That would help avoid the Chaos realm and all the problems it causes.
Always find it hilarious GPS essentially started with some tech guy trying to test if general relativity works.
4:47: 3 billion stars. That's not sci-fy anymore. The Gaia probe has already measured almost as many objects. For almost one billions stars it got the position, speed, heading, color, magnitude. We can visualize our neighborhood pretty accurate and could also calculate our position. Well... if we could travel this far. But even a billion stars isn't much. It's just 1% of the galaxy. There are some neat visualizations out there showing the stars based on that real data. And we didn't even use Borg tech.
What about orbital dynamics ?! You get the shot from Alex in Rocinante planning some crazy orbital manovers
I would expect a populated space with established travel routes would also use some form of beacon, much like the beacons used in early transcontinental air travel. for a planet, there would be a geostationary beacon "ahead" and "behind" it in orbit, for a star system, one beacon would be enough for interstellar FTL travel, because it wouldn't move enough in the travel time to require plotting an intercept.
It’s pretty crazy how all the tools we need to survive in space are there. We just have to figure out what they are and how to use and understand them. I like to believe that if we weren’t supposed to be out in space we wouldn’t be able to even leave earth in the first place. I think of Earth as tutorial island at the beginning of a game. We have to learn as much as we can down here so that way we can apply all of that out there. It’s forgiving here on earth to some degree (please don’t burn me at the stake for saying that, these are just my observations) But out there it’ll require a lot of team work. There wouldn’t be room for prejudices or petty grievances. The bigger picture would have to be the mission. A future for all generations to come. Just like the sacrifices people made before our time. The hope for a better life for those that come after.
Even submarine launched ICBMs use star navigation (amongst other systems, of course)
The spacecraft knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the spacecraft from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.
In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the spacecraft is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the spacecraft must also know where it was.
The spacecraft guidance computer scenario works as follows. Because a variation has modified some of the information the spacecraft has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error.
In our latest SF novel, we use pulsars for fixing positions.
It'll be interesting when GPS goes from Global Positioning System to Galactic Positioning System...
Some of those methods work for low velocities relative to the light speed, get closer to light speed and they don't work so well.
Hi Spacedock. Could you do a video on a possibility of a real world Homeworld type ship. So is it possible create a mothership that is entirely self sufficient and could be park next to an asteroid belt and mine and build fleets of new ships. The mothership wouldn't have access to a planet so it would need to be built to house anything it would need. mining facilities. refineries/ manufacturing, you would also need to support the crew so you would need on board farms and food processing.
My own StarWars headcanon: Astromech droids are startrackers, using the stars to determine their EXACT location. Instead of a simple catalog, they use a map of the ENTIRE galaxy!... or as much of the galaxy as has been reliably mapped, anyway.
Thanks for the content.
Speaking of navigating. I’m kinda wonder how many ship’s helmsman in sci fi able to pull off an extreme maneuver with just a touch screen? I mean, think about those USS Enterprise E conn and the Expanse iPad like thingy that the pilot uses, it looks rather hard to use that to control a massive aircraft given how cumbersome they would be.
I like the Ariadne network used in Gundam Iron blooded orphans, i guess those would be similar to subspace beacons used in Star Trek
yippie space engineers music again 🥰🥰 my scifi origin
In a story I'm working on the way the characters find out where they are in the galaxy is by which ring they are in, out of nine and going out from the core, and then by use of six pulsars that can be seen.
What if, instead of using nearby stars that are visible with current technology, interstellar travel made use of powerful telescopes that could resolve individual stars in distant galaxies, making their positions relatively the same for all nearby star systems.
In the sci-fi I'm writing, a lot of terms are absolutely arbitrary. Like the "north" of a solar system is determined by the poles of the primary, and the plane of the ecliptic when (most) planets are orbiting counter-clockwise, and headings are based on an angle between the bow and the primary, with the primary always being 0.
I liked how in Lost Fleet series they used good old "port/starboard" for directions - but instead of our arbitrary "left/right" it meant that "starboard" was literally "towards the star". So at any location of any star system you could easily issue directions to your fleet no matter how each ship was oriented in the 3d space
@@nickcher7071 That was a clever bit of worldbuilding and a good way to go around clarifying language. I definitely took some inspiration from that.
what about the newest real life gravity wave detectors that bsacly use lasers via gravty wave vidrations to bascly when disurbed by the menuite difreaces of the lasers pathways caused by gravty waves intracting with the laser beams can be bascly used to detect and navgate in deep space. also they can also detect thsoe gosh darn alein gravity wave ftl drives realy easly too by the way if you got enotgh of them to trangalte where they are bascly.
a) Gravity wave detectors are HUGE. And ridiculously sensitive bits of kit. (They can pick up your footsteps from KM away, sensitive.) b) GRavity waves are not regular, repeated events as a rule.
Even in the age of sail, dead reckoning was considered a huge risk
Dammit, I'm not the only one who read "realistic space travel" as _"relativistic_ space travel", right?
In the Expeditionary Force series Book 1 "Columbus Day", Human Soldiers were taken to train on Alien Weapons on another planet and they brought astronomers with them to figure out where they were in the galaxy by looking for stars they knew their characteristics.
Can you do a video on galactic mapping with sci fi cultures that have FTL. The first issue I see is that because the ships move much faster than light in these settings, which means maps need to account position and distance to determine where a Star should be via FTL, rather than the light that would be showing the stars past position.
If I (a tourist) saw that map and didn't read to carefully, I would just assume they were experiment with some new map design.
This is a topic i have always wondered.... But Interstellar travel. WHere the travel time is so long, that the destination stars movement have to be counted accurately, or you miss your target... Not just point at it, To sirius, just point at it and you head for the location where it was 8.7 years ago. You have to count its present speed and heading.
Another example of building a star map, albeit less realistic, is seen in E.E. "Doc" Smith's Skylark of Valeron, in which the heroes have been displaced so far from home they literally don't know where they are in the universe. Their saving grace is the incredibly detailed star map that was produced by the genocidal race they'd recently just finished exterminating. In order to get home, they have to build a ship/observatory with graduated circles a thousand kilometres in diameter with which to map the entire universe to the required precision.
It takes a while before the map they've built matches up to the map they've got.
I design underwater systems and its like this apart from there's no visibility, no RF signals and you get pushed around more 😂 Space would be massively easier!
For the IMUs, of course gimbal lock is a problem.
Are there any spectra from pulsars that could be used to fingerprint each one? Such that if you were traveling faster than like, you could work out which one is which and therefore use that to determine your location?
It seems to be that other otherwise for fashion light travel the only alternative is for artificial intelligenceto know the locations of the various pulsars and extrapolate the possible combinations based on their positions and movement although with Fast and light travel, they’re movement relative to each other would make a larger difference depending on how time was dilated.
Inspired, yes.
Modern high tech dead reckoning is an underestimated level of accuracy...
Accurate time is very important to GPS calculations. Due to gravitational effects clocks in orbit actually run 45 millionths of a second faster than they do on Earth's surface. So, Earth bound clocks have to add that into their calculation. This can be a problem where the gravitational field varies. Say where the mass density of the Earth is higher or in places where space-time seems to be disturbed (cough: Skinwalker Ranch). Anything that disturbs gravity thus altering the flow of time can throw off GPS. It's not very useful around a blackhole.
What about looking into gravity?
Relative twards mass of specified gravitational strength?