K^2

So what would be a good name for it? I'm not asking for a better name, because that'd be just about anything, but a good one. A "Navy" rather than a "Force" would probably be a good start, but "US Space Navy" still sounds kind of dorky. Again, overwhelmingly better, but that bar is practically buried. "Astral Navy" would be on brand, but it makes me picture energy crystals and meditation. Not the right fit. "Orbital Navy" has a good ring to it, but it's very Coast Guard in concept. Part of it is that we might be getting hosed with an English language here. I bet Germany will have a fantastic name for that branch of the armed forces. It might still just literally say "space force," but it will sound cool. Then again, Russia had every opportunity to make something good, given the flexibility of the language and rich history of space-themed fiction, and then completely blew it. So maybe I'm giving Germany too much credit too. But I'm still curious if anyone has better ideas, whether their own or encountered in the wild.

@TROPtastic Yeah, the problem isn't with a structure that can move through space-time at whatever velocity. I honestly never looked into that too deeply. The problem is with taking matter here and making it go over there. That requires either forming a warp bubble around an object, transporting it, and dissipating the warp bubble, or trying to hop onto a structure that's passing by. I was discussing strictly the former method. We can do more comprehensive analysis when we start with ship being the only source of gravity prior to warp and after the warp and place very strict requirements on the whole procedure that way. The outcome of that analysis is that either the space-time around the warp bubble is flawlessly flat, requiring negative energy densities, or the accelerating bubble produces gravitational waves that require energies comparable to a photon drive. For FTL case, that energy requirement goes to infinity, so the cancellation has to be flawless, but for sub-light "close enough" could reduce energy requirements to sensible levels. Now, if you have a structure that's already moving, we reduce the problem to hopping on. The issue, however, is that if it's an FTL soliton, then how do you even without already having a warp drive? That doesn't mean it's not an interesting concept. If these solutions are physical, there could be any number of FTL solitons bouncing around our universe. If we can learn to interact with them in any way, we can at least try encoding information, and having an FTL broadcast capability would already be huge. If you give me a few bits of classical data over an FTL channel, I can walk you through turning it into a proper interstellar high bandwidth network with this easy trick quantum physicists don't want you to know about a modified quantum teleportation algorithm using entangled photons as carrier. Still doesn't help you move ships, unfortunately, unless you go full stargate on this concept. Which, maybe you do, but that's an entirely separate can of worms.

Have you read the paper? Do you understand the physics of the warp drive? This is the specific mistake in the text. You can't make the space in that region arbitrarily flat if you have a non-zero mass ship within the bubble without screening the curvature with non-positive-definite stress energy in the warp bubble. QED. Keep in mind, this isn't a peer-reviewed paper, and if I can find problems in it that quickly, it wouldn't have survived a peer review process. The underlying symmetries in Newtonian and General Relativity physics has not changed, and that underlying symmetry is what kills the concept. And on a less fundamental note, your argument is essentially that the very principles on which we build the idea of warp drives could be flawed. Which, ok, maybe. But then you jump to conclusion that it might make that technology more plausible? I think not. If GR is incorrect, then we're just making up a fantasy drive that has no chance of ever doing anything. Sure, there might be other means of propulsion somewhere in physics unknown, but it might as well be unicorn farts at this point. The sum of all of humanity's knowledge tells us in a dozen different ways that warp requires exotic energy. Is that possible? We don't know. The requirement that we balance out the energy perfectly to create a flat region of space-time beyond the bubble is rather precise, however. It has to be effectively flawless. Clasically, that's problematic. So the idea of practical warp drive lives or dies on quantum gravity. And this is, unfortunately, where our models hit a big fat divide by zero, almost literally, and we need a better approach to the theory before we could even properly model the quantum behavior of a warp field to see if it's going to be possible to make it into a stable configuration that "wants" to stay in tachyonic regime. The other bit of good news is that while a flawless warp bubble is necessary to go FTL, for subluminal warp, you are allowed a margin of error. If the space-time beyond the bubble is merely nearly flat, then you are generating wake of gravity waves compensating for the non-zero accelerating mass. That means acceleration will sap energy, but potentially orders of magnitude less than it would have taken to accelerate without warp. That's not bad. Of course, you still need that negative energy in the bubble, because without it, the gravity waves you generate have to carry all of the compensating momentum, and that means you'd be better off, energy-wise, to just have a photon drive. Finally, a subluminal warp doesn't have to have a static warp bubble. We don't know if a static configuration with negative energy density is possible at all, but dynamically unstable systems with regions of negative energy density are well known. There are even published works showing that oscillating warp field can reduce the amount of negative energy required. The net mass of the ship and bubble still has to be close to zero, which means the ship will have to emit an enormous amount of energy on departure and absorb it on arrival, which is way more energy than we know how to deal with, not to mention all of the engineering problems of maintaining bubble stability given that it will want to collapse to the ground state instantly absorbing the ship as such into a net vacuum with a small puff of radiation... We're basically at the stage where we're trying to figure out how to ride a steam rocket to the Moon with all of this. But you know, at least we're making progress. One thing we know with absolute certainty - if we manage to come up with practical warp drive as prescribed by general relativity, it will involve some form of exotic energy. Anything else is the violation of the very principles going into designing the thing.

Mhm. I think the only reason to re-cert should be if you want to replace the ship, whether because you want to upgrade the tech used, replace it with better-built one, or just because you feel like it. Having to re-fly the routes that work fine and you are happy with would get really old really fast. It has bad game design written all over it.

We know quite a bit about what's not planned for the game, like more sci-fi tech, military tech, etc., and if the devs were to provide early access to certain modders, the later would have all the knowledge they need. That said, I don't think it's necessary either. I would honestly like to see modding tools and perhaps even Workshop integration in the kind of state that we can see small mods and KSP1 mod conversions showing up on day one simply due to the ease of use, but I don't think early access for modders is necessary. I'm also not too worried about whether or not Intercept provides the kind of support they were promising early on. Don't get me wrong, it'd be helpful and would make modding cleaner, more stable, and less likely to break with version updates, but it's not critical. Back in early days of KSP, the community was small and Unity wasn't as well established, so a helping hand was needed to get modding going. Now we have a mature modding community that's eager to jump into KSP2, and generic tools for modding Unity games have gotten way better. We have asset exporters, code decompilers and disobfuscators, decent launchers with hooks for mod loaders... A Unity game can be modded even if the devs don't want you to, let alone when they are simply indifferent. So one way or another, there will be KSP2 mods. But how long it takes for quality mods to start showing up and how easy they will be to install and maintain will depend on Intercept's support.

They do. Net mass of the ship under warp has to be zero. I know a lot of theoretical work is missing out on that requirement, but they're also working with bare bubbles with no source of curvature within it. At a minimum, you need amount of negative energy to cancel the ship's mass. It's a somewhat interesting topic with a lot of math, but the caveat is you want a drive that acts locally. Sure, universe can expand at FTL rates, but because that expansion is inherently non-local. If you can lay out rail from here to destination and warp space all along in any way you want, you can avoid this restriction. But if you can draw an imaginary bubble around your ship and the warp field and say, "The warp effects only space within this bobble," then you can pull in some theorems from tensor calculus and the fact that stress energy is a conserved flow under GR and show that non-zero mass warp would cause problems. Alcubierre Drive works precisely because a bare bubble has a zero mass. If you place a source of gravity within Alcubierre Drive, you actually have to adjust the metric and end up with mass of the bubble being exactly negative of the mass of the source. It's a wonderful example because the math for AD is comparatively simple and these results can be worked out explicitly. But we also know that it's a fundamental limitation. Any fully contained device capable of going FTL has to have a net mass of zero. (Edit: Or if it moves from one location to another without something absorbing recoil, I should add, even if you don't go FTL. You can actually show that it's the same requirement for both these things AND time travel by using the fact that there are no absolute frames of reference in GR.)

This is fully equivalent to a perpetual motion. It's relatively easy to show that a closed system cannot generate thrust in principle. Unfortunately, being absolute crackpottery doesn't stop someone from submitting a paper and having it show up on a NASA website. Bottom line, this does not work, cannot work, and there is no need to even consider the details any more than if someone was suggesting pulling themselves along with a magnet. This is just as stupid and for all the same reasons. No matter how much somebody thinks they've found a way around the most fundamental conservation laws, they haven't. There are only two ways to move through space. You either gain momentum or you warp the space. Former requires an exhaust and later requires negative energy in sufficient quantity to screen the contained mass. In either case, momentum is conserved.

That graphic is a bit outdated. We know that fusion drives are going to be a part of future-tech, so we know at least one type. We also know that fission fuels are a thing, so NTRs are pretty much in, but whether you count them as part of future-tech or not is kind of up to you, as we did have one of these in KSP. I think the only fuel type still with a big question mark on it is antimatter. There are some shots in images and trailers released that kind of look like they could be beamed core AM drives, but it's hard to say for sure. As for magnetic sails, I agree with Wubslin. In the Solar system, the light pressure exceeds solar wind pressure by a decent factor. There are definitely some advantages to a mag sail, but if Kerbol is modeled after Sol, they'd still lose out to solar sails in most situations. If we're going to have either of these, I'd put money on solar sails, but I have strong doubts even about these. You need huge structures for these to be practical, and in a game like KSP, it's hard to make it work both in terms of gameplay and actual game tech. Mag sails would have to be even larger to be practical and wouldn't feel any different in terms of gameplay. I don't see any reason to go for them.

You'd be surprised. In my experience, you either don't have a writer at all in preproduction or borrow one from another team and contract out the bulk of the work. Even once the game is in full production, the lead writer is very frequently a contractor. And the two types of games I've spent most of my industry career working on, funnily enough, are the MMO RPGs and very story-rich, narrative-driven games. Obviously, at two very different studios. Both of them have had full time writers employed, but they were primarily responsible for writing additional character dialog, side-quests, fleshing out details in main story, etc. Not to make their work sound less significant, mind you. It takes a lot of talent and dedication to write good dialogues for pre-established characters or to add new side-characters who balance out the story. However, the core would be written by a well-known writer hired to do a unique story for specific game or major update, and while that can happen pretty early in the game's creation, because that writer is usually quietly contracted through agencies, we won't hear about it at least until the game is announced. I mean, don't get me wrong. I still think that a large scale RPG is unlikely, but the fact that they aren't hiring writers for it is not an indication one way or another. Yeah, that's what it reads like. If it weren't for mention of interest for space exploration in the list of preferred qualifications, I'd bet on something like a Kerbal Kart Racing or something. (I still think it'd be a good enough idea.) But with that line in mind, maybe a colony-building game? Nothing too grandiose, I don't think, but something like Fallout Shelter, Oxygen Not Included, or maybe even a more family-friendly take on Rimworld with a Kerbal theme and some unique twists could really sing. Basically, more about resource management than grand strategy, and with relatively simple graphics, relying more on game mechanics to keep it interesting.

Except for the bit that we don't know (and based on current understanding, probably can't know) if that rubber band is actually infinite, has end points, or loops around on itself. Although, to be fair, unless something changes about our understanding, it can't possibly matter which one it is, either. Also, the way you said that bugs move apart from each other initially makes it sound like bugs are moving along the band. It's a semantic ambiguity that's more to do with the language than anything, but maybe if you start by saying the band is stretching and that's why bugs are moving apart? It is a bit of a cart-before-the-horse from historical perspective of understanding it, but does provide some clarity. Idk if it matters that much to the explanation, though, as consequent sentences make it clear that it's the band that stretching and not the bugs crawling on it.

I mean, how precisely do you need it? At subsonic speeds and in low supersonic regimes, to a good approximation, drag is FD = (1/2) CD ρ A v2, where ρ is density of the relevant fluid (air), A is cross-section area, v is velocity relative to the fluid (air), and CD is the drag coefficient. That last one is the hardest to estimate. For a rough order-of-magnitude estimate, CD tends to be close to 1 for subsonic flows. Wikipedia article on Drag Equation has a bit more detail. If you need it more precisely than that, yeah, you'll need to either do a scale test in a wind tunnel, keeping Reynolds Number consistent, or do a numerical estimate of the drag by simulating the flow, which gets comically complex. Lacking a wind tunnel, there are a few tricks you can play. If we are talking about a model rocket, you can drop it and see how fast it falls. It's possible to estimate drag from timing the time of the fall very precisely. Of course, you'll want to have either a way to catch the rocket safely or be prepared to crash a few replicas. For a real rocket, you can use the fact that Reynolds Number scales with density and test a toy-sized replica in water. That would let you measure drag forces at much lower speeds. If you get the size and speed correctly to have the same Reynolds Number, measure the drag force with a spring scale or similar, and compute CD for the model, it should be very similar to that of a real rocket.

The whole point is that you don't really need anything to handle VR. Unity already handles VR. A 2D UI needs to interpret your intention when you're moving a part with a mouse, which is why snapping issues exist - misinterpretation of intent. VR UI doesn't need to interpret anything. So you simply inject the input one step further upstream and you're done. The challenge is entirely in building up the menus and ability to select parts you want and get information you need about the rocket you're building. The actual building process in VR is the easy part. It's something a Unity-savy intern can set up in a day. Back when I tinkered with it, it took me a couple of hours to go from, "Hey, I have a working Unity project," to "Hey, I have a Unity project that works with VR." Granted, I had a lot of prior experience, with all relevant systems, but it doesn't look like Intercept is hiring people who learned C# yesterday. Again, I want to stress that there's a lot more to making an existing game into a VR game, but the points you're focusing on are the ones that are simply a non-issue. Grabbing, moving, and attaching objects is by far the easiest thing to do in VR, and especially, if you have an engine/platform that's built around it, such as Unity.

You know the only correct way to title this game will be Eve Online, right? What? Take Two has lawyers. They can figure it out.

You're not wrong, but you generally don't stagger full teams on your flagship IP. If they, indeed, want to start working on KSP3 ASAP, they'd still want key developers from KSP2, like creative director, to roll over to KSP3 team. That does mean that you want pre-production on KSP3 to finish right around the time KSP2 ships - no earlier. And I just don't think they'd have a long pre-production planned. Six months form now is still December of this year. And I don't think anybody expects KSP2 to ship before summer 2022. This feels entirely too early for pre-production on KSP3. (Granted, some large games can be in pre-production a lot longer, but nobody usually plans for a pre-production hell, and smaller studios try to keep pre-production period short and lean.) I also doubt that pre-production of KSP3 would get approved before we see at least pre-order numbers on KSP2. It's more realistic that KSP3 concept isn't even going to be worked on until after the KSP2 ships, meaning pre-production in late '22, early '23 - that's if they go for it at all. So way, way too early for something like that. On the other hand, odds are, some people will start rolling off KSP2 late in Alpha through early Beta. There will be a lot of stuff to finish and fix, but you often don't need all hands on deck for it. It's entirely too late to do concept art, for example. And even among engineers, there are these who are better at laying down new systems than fixing stuff. So you usually want somewhere to roll people over, because firing and re-hiring later is a huge waste. Now, KSP2 is going to be rolling out of alpha early '22 baring any disasters, so if they started pre-production on another project, say, around now, they'd potentially get green-lit around January and be ready to start taking on additional developers, like ones rolling off KSP2. So yes, I think you have a very strong point, and I think it would be smart of them to utilize KSP IP in some way here, which it sounds like what they're doing, I just don't think it's anything like KSP3. And I know you didn't explicitly say it, and maybe you weren't even thinking it would be a direct sequel, but I did kind of want to break down in a bit more detail why I think it sounds more like a spin-off.

They have the leads positions in engineering, art, and design open up at the same time. That's basically your trifecta for a pre-production. It's like if a fighter, a cleric, and a wizard walk into an inn, you know they aren't there just for drinks. The odds of intercept still needing to add or replace all three at once are, appropriately, astronomically low. This is definitely for something new, and the flavor text on the req matches that pretty well.

Can't argue - it's a stretch, for sure. But just because we're not coming up with something on the spot doesn't mean they didn't find an interesting opportunity over months of development. That's just normal recruitment embellishment. Everything about it looks like a dedicated project.

I think, there are a lot of issues at the terminal end. You can inexpensively retrofit just about any infrastructure running on natural gas to hydrogen, from kitchen stoves to power plants. Ethanol? Not so much. Obviously, you need completely different way of generating fuel-air mixture. You can't just squirt ethanol out of a pipe and light it. You need to create fine spray, mix it with air... That's considerably more hardware than burning gas. But there are less obvious problems too. Ethanol will contain up to about 10% water. It will literally pull it out of air, so avoiding it is exceptionally difficult. That's enough water content to start causing problems. And if your pipes were not built to withstand corrosion and now they suddenly have to, well, that's a problem. I don't think it's going to do any appreciable damage to the pipeline itself, but various control valves and thinner pipes at the terminal end are another matter entirely. So I don't think ethanol is a viable alternative even before we get into questions of pipeline physics. But yeah, moving something that dense will require adjustments. There might be portions of pipelines that simply aren't designed to withstand the weight of the pipe filled with ethanol. Nearly a ton to a cubic meter is no joke and adds up really fast. I don't think we have seen anything in exoplanet observation that contradicts the notion. That said, some detection methods rely on the assumption that planets mostly move in the same plane, which means you can't rely on this information too strongly. But I think most of the data comes from observations of young stars with detectable protoplanetary disk and computer modeling. The Wikipedia article on protoplanetary disk actually has quite a few pictures of the ones we've been able to image directly. And we're mostly seeing things consistent with computer models.

Nah. A Designer/Artists/Engineer leads + senior Eng is something you do for a new game, not a port. The recs for all four are way above what you'd expect for the title, so this is intended for a team that's going to grow. It can still be DLC, but spin-off sounds more likely. And yeah, that desc does make mobile unlikely. This is either stand-alone console/PC Unity title or a fairly serious DLC.

These things, they take time. So it's not out of the question. But it kind of sounds like a skeleton team for a pre-production work on something that hasn't even been fully approved, let alone announced. The fact that there's a Lead Designer and Lead Artist that go along with the two eng jobs sound about right for this as well. Whatever it is, it's definitely space-related, almost certainly still KSP IP, and is going to run on Unity. That still leaves a lot of room. Exciting. Good find.

These are partial derivatives. I'm not entirely sure what L is meant to stand for, but first one is how volume changes with pressure at constant temperature, second how it changes with temperature at constant pressure. These are related to compressibility and thermal expansion. I suspect that L might be "limiting" as in "limiting flow," which would make sense for a rocket exhaust, but I'm kind of guessing on it. Mass per mol. Critical velocity of the fluid. Abbreviation for "sonic velocity".

Not really. You can get 1T to 1km/s for about 140kWh, which is less than $100 of electricity from outlet. (Potentially, way less, depending on where you live.) It'd be more expensive to produce that power in space, of course, but it's still not a lot of energy. Recoil still has to go somewhere. If your launch system is in orbit, you can't exactly tether it. If ships are constantly coming and going, then maybe the net impact averages out pretty well, but if you're just using it to send things to outer Sol, you'll quickly run into a problem.

They're different states. It might sound like pointless demagoguery, but it actually matters when you start counting possible states a system can occupy. Say you have two coins. Each one can be heads or tails. You have 4 possible states. HH, HT, TH, or TT. But if you can't tell between the two coins - if they are truly indistinguishable on most fundamental level, then TH and HT are the same state, and there are only 3 possible states for the system. Elementary particles behave this way. You don't count exchanges as distinct states - they are all counted as a single state. And this actually has consequences on things like entropy of the system.

I wouldn't bother repositioning ISS. With this lift capacity, we can build a station whose habitable section is actually designed for 1G. Not to mention that you need the hub, the counterweight... This ought to be a new construction. And probably in much higher orbit to reduce tidal effects. Yeah. Black-body radiation page has a bit more info. Ooof. So I can probably dig into a bit more if you want, but the very short version is that all particles are identical. It is fundamentally impossible to tell between a particle moving and a particle being destroyed and new one created in the new location. In fact, the later is how we describe propagation of particles in QM. So this gets very philosophical very fast. I can claim that "they are all the same photon," as particles are indistinguishable. But I can just as easily claim that a photon only exists for an instance in time and no other photon is the same photon, because no photon at any other instance of time shares that same state (which includes time). Scatter, absorb, or both. It's not just about density, though. Water has almost the same density, but will cast only a very faint shadow, while there are plenty of gases opaque enough to absorb light. Interaction between light and matter can get fairly involved. Yeah, that's how radiative heat works. Of course, there can also be convection - if you hold your hand over a hot object, hot air rising from it might be heating your hand directly. Unless you're in a vacuum, it's almost always some combination of radiative heating and heat transfer from environment. this is just about the time it takes for energy to propagate out of the star's core. There are a whole bunch of state changes along the way, and this eventually leads to emission of light in photosphere via black-body radiation as described in an earlier link. It sounds like your understanding of the process is essentially correct and the article is just poorly written. Edit: Ninja'd by @AHHans I could have written a much shorter post.

I know we've been stuck for almost half a century without a superheavy, and that kind of warped our perception of what we can reasonably construct in space, but with SN20 scheduled to take flight this year, giving us ability to put 100+ T to LEO in one go, which is a quarter of the entire ISS mass, should we start talking about at least a tethered centrifuge station? It seems like a silly waste of time to even experiment with trying to acclimate astronauts on Earth when 500m of cable solves the problem pretty much completely in orbit.

Sort of, but linac is a lot cleaner. Rotation gives you an illusion that you can accelerate gently over time. But reality is that you are still moving in exact opposite direction from one side of the loop to the other. Which means you have to have accelerated in between. A circular rail just trades linear acceleration for centripetal, and you still have to deal with extreme G forces. With a linear accelerator, what you see is what you get. If you can build a rail 1km long, then you have 1km to get to whatever target speed you have in mind. Unfortunately, 1km is really, really not a lot for speeds we want to build up. In terms of practicality, not to rehash all the conversations again, unless you can get your cargo up to something like 10km/s at a significant angle up, a sea level rail-assisted launch just isn't helpful. If you want to get any sort of benefit from rail launch, the exit point has to be in rather thin atmosphere. As supporting something like this with a static structure is pretty much impossible, we kind of end up all the way back at launch loop concept. Which, you know, is a thing, but not exactly on currently achievable scale.