K^2

Sort of? I mean, we obviously can't know for sure until we figure out the problem. It can always be a case of, "Scientists discovered one more particle. The Standard Model now matches all experimental evidence perfectly." But if I was placing bets, I would definitely put money on things being way more complicated again. That said, the level of fines at which you have to split hairs has definitely gone up a notch. A new theory wouldn't just have to explain the discrepancies. It would have to explain why we're getting such good results in many other experiments. Why is the anomalous magnetic moment of electron so darn close? It's not as simple as the case with Newtonian forces being just, "We never measured them precisely enough." We do have measurements that are precise enough in conditions where the match between experiment and theory is extraordinary. And then we have exceptions, which are few, but oh so annoying. Another thing to highlight is that GR doesn't just invalidate all of classical mechanics. Conservation of energy and momentum are still there. You have to be careful with them in warped space-time, but the concepts are most definitely there. The difference is that we used to think that Newton's Laws are fundamental and conservation laws are a consequence. And now we know the conservation laws to be far more fundamental, being consequences of symmetries of space-time and fields within it. And because of the conservation laws and action, Newton's Laws fall out naturally as a good estimate to average dynamics. It's entirely possible that next major upset in physics will bring with it another paradigm shift, and maybe we'll find that symmetries are just approximate as consequence of something else, or whatever. But the fact that local symmetries are connected to local conservation laws is here to stay, and that means that we can't have something that's just completely new physics, it really has to be something that builds on top of what we have now. Not that this has ever been any different in practice. Just that now we have way more reason to expect this to persist. Finally, there are some principles in physics that never change just because they aren't really physics. Allegedly, Einstein claimed that the one part of physics he'd be most surprised about ever changing would be thermodynamics. And I can't disagree. The basic principles were invented when people thought heat was a fluid. And entropy was just a funny consequence of the equations - a quantity that happened to be convenient to define to do math with. In that sense. But the underlying math is solid. We have substituted new concepts for what all the individual parts mean as our understanding grew, first with classical statistical mechanics, and then with quantum mechanics and condensed matter physics. But the math's just math. That isn't going anywhere. And so thermodynamics still works. We just know that heat is measure of internal energy of a system and entropy is a measure of disorder in that system in a way. All new physics, new understanding, but same thermodynamics. I expect same of Quantum Mechanics. People always say that it's the one that looks the wonkiest, but that's just at the level of interpretation. Most of quantum theory is actually just math. Interpretations might change, we might get new underlying physics, completely new understanding of what a wave function is. But the math is still going to be the same. So we'll still have Quantum Field Theory of whatever's going to be the next big thing. And this is the sort of thing in which I think we're in different place than early 20th century physicists. Everyone back then knew that change was coming. Experiment after experiment crashed against accepted notions. But what nobody had any idea of is how much of physics was about to change and what was to remain the same. We now have a bit of hindsight to work with, and I'm feeling much more comfortable about certain areas of fundamental physics enduring even if we have to throw Standard Model and much of General Relativity into the garbage bin. Fair warning, this is me just being in maximum pedantic mode, but I wouldn't phrase it like that. Special Relativity is a special case of General Relativity, so it certainly has a few things to do with precession of Mercury. But yes, SR is not sufficient to explain precession. General Relativity and Schwarzschild solution of Einstein Field Equations for vacuum are necessary to adequately describe motion of Mercury. And yeah, that came about a bit later. Specifically, Schwarzschild's work was only published in 1916.

Open betas, generally, don't really give you any data you won't get with just launching the game, and the hit on your servers, if relevant, is going to be about as bad. So it really doesn't help. Sure, it might sound like it's better to have game-breaking bugs in beta, but the impact is the same - you're airing out your dirty laundry. Except, with open beta, you're doing it in front of people who haven't bought the game yet. So as long as you are planning to fix the bugs anyways, it makes more sense to just release the game. If it's ready to go - release it early. Or more realistically, do take the time you would have been running beta to actually fix the bugs you already know about and get the best release you possibly can. The only time open betas are even done anymore are as a hook for pre-orders, and anyone who cares about games shouldn't be pre-ordering. Yes, it can be tempting, but if all you care about is beta, just wait for the game. It's better for everyone. (Note, we're talking about major releases here. If you see an Early Access from an indy dev or a Kickstarter you actually believe in, by all means, help the devs make that game by giving them your money early. Large publishers don't need to be fed like that. It's their job to invest into future earnings.) Closed betas are a different matter. It's still not always beneficial to run one, but it often enough is. What usually differs from game to game is how exclusive the testing group is. I've seen cases where it's just devs' friends and families that get invited, and you get enough coverage this way; and I've seen cases with open sign-ups in published ads, because devs wanted to throw a lot of bodies at the servers for a couple of days. Either way, the critical part is developer deciding how many people they actually need. If you need to stress-test your servers, it's a good way to do so in a controlled manner. You are also getting people who, presumably, jumped through some hoops or have some other attachment to the game, and are therefore more likely to actually submit crash reports, which can be great for finding these hard-to-reproduce bugs. Finally, with limited exposure, even if your beta turns out to be a buggy mess, your impact on sales is likely to be minimal. Even if somebody starts leaking info and it gets picked up by gaming news, it's still far more likely that people will brush it off as par for a closed beta. In summary, open beta - definitely no. Closed beta - probably yes, but kind of depends on the needs of the dev team as things get closer to release.

Stock KSP has aerodynamic shells, so it's not like we've never had stock procedural parts. But yeah, there are definitely more opportunities there. Wings and tanks are high on the list for me. And with tanks, I don't even want much. Just give us ability to resize them vertically in the increments of the smallest tank up to the largest, for example. Having, like, 8 different parts for these is not helpful for UI clutter. And even then, if I want to create a tank that's 3/4 of maximum size, I have to stack two tanks on top of each other. That's a needless addition to part count and simulated joints, which starts to matter when these are part of your asparagus cluster. Procedural wings would definitely be a more advanced feature, but it's another case of having to either deal with very limited selection or building out of a lot of pieces. Keeping part count low is in everyone's interest, so I think it'd be worth the time spent designing a good UI interface for building the wings.

@sevenperforce I'm pretty sure you're looking at bounds on neutrino oscillation frequency based on bounds on neutrino mass. If we knew the exact oscillation frequencies, we'd know masses of all the neutrinos, which would be big news. As for the topic at hand, Higgs boson was basically the final nail into the coffin of any hopes that standard model is "nice and simple." Having just the U(1)xSU(2)xSU(3) symmetries with a boson field for each would be a sort of thing that I can look at and think this might be all there is, with just some oddities like the neutrino handedness and broken electroweak symmetry to be explained. With Higgs being confirmed to be the cause of the electroweak symmetry breaking, it's clear that there is no simple pattern to this representation, and if tomorrow they announce that they've found another field that interacts with SU(2)xSU(3) part, or a new SU(4) symmetry, or even one that doesn't fit the unitary group pattern, I'm not going to be surprised. The fact that we're finding out about it indirectly via anomalous magnetic moment measurements is just par for the course. Wake me up when there's a good candidate correction to standard model that fits new observations or if anybody comes up with something better.

I love space. Absolutely nothing happened, but there is enough tension and buildup for a novel in this thread alone.

My argument is that countries that aren't signatories to OST don't recognize space as being beyond their territorial limits, nor the fact that they cannot lay territorial claims on anything in space. Such nations can easily claim the debris as the extension of their territory. Declare it a consulate or a vessel in international waters if it helps. It's paper thin, sure, but if there is no reason for any other nation to specifically challenge it, then maybe it's good enough.

I'm going to liberally interpret this as you having some reliable information about impending collapse of all civilization in the next seven years and commence panicking over it.

Very unlikely. Our productivity, speaking of game dev in general, wasn't hit all that bad. Burnout's worse, but I don't think that was factored into schedules. So all we're getting is that there won't be additional delays due to teams burning out a lot faster than they used to. Initial hit of having to figure out how to work from home has impacted some studios pretty badly, but even that's not across the board. Most of us kept working pretty much the same way we used to before. Just a lot of meetings that, "we couldn't possibly have over Zoom," we are now having over Zoom. A lot of the delays that got blamed on COVID were going to happen anyways, and even in cases where it was a contributing factor, it rarely was the sole contributing factor.

Iron and Nickel are pretty close in abundance in Sol system as elements, but I have no idea about asteroids. They might not have the same relative distribution throughout the system, which can easily lead to one being flung at Earth more commonly than another. I have no idea if one is actually more common than another, however - just speculating on possibilities.

I would really like to see an update on procedural vegetation, forests of Kerbin, and maybe a sneak peak at some alien flora. Also, it's pretty clear Intercept is shy about showing their physics progress, but it'd be nice to see at least some demonstration that it's happening. Surely, they can have a rocket or plane with smaller part count in action by now.

As much as NorCal has changed with tech, I live a stone's throw away from surfer country, and I can hear that last line.

I really appreciate that you clearly did research on this. This almost reads like a legal opinion. So this one might be sticky, but my (admittedly limited) understanding is that space is only outside your nation's borders if you are a signatory to Outer Space Treaty. Quick lookup shows that there are nations that are signatories to NPT, but not OST. These nations can claim that launching a manhole cover vertically up doesn't cause it to leave their borders, while at the same time have the right to request a nuclear detonation on their territory subject to NPT. Notable candidates would include Turkmenistan, Uzbekistan, Tajikistan, and Kyrgyzstan. I'm guessing because they haven't bothered to sign OST following collapse of USSR. Of course, any nation that could provide a nuclear device under NPT is also a signatory to OST. So I don't know if they would apply their definition of nation's borders and it would then be considered a violation of NPT from their perspective? Or is it only the laws and treaties of the nation where the test would be conducted that apply? Thoughts? Mining companies tend to use slow explosives, though. These are usually tertiary explosives that are a bit easier to work with in large quantities. So yeah, finding anyone but military that can conduct such an explosion might be problematic.

New? That was a done deal with the first "Again!" I only wish other people would understand when I quote it instead of giving me odd looks. v_v

Not all the same, but there aren't that many elements that are abundant in asteroids. And the ones that tend to make it deeper into atmosphere before exploding tend to be metallic, AFAIK, which limits it even further to primarily iron, cobalt, and nickel, all of which impart color to the explosion. Iron tends towards orange red, cobalt is yellowish white, and nickel is greenish.

If that 300T yield thing is correct, you can do this with HE. Just set up detonator at the bottom, so the shock accelerates through secondary as it goes up the shaft. The shaft is tall enough that by the time the shock arrives at the top, there shouldn't be any substantial difference between conventional and nuclear explosion at that yield. That's still a lot of explosives, and I don't know if a demo company would be allowed to handle that much, but it still ought to be easier to get than a nuke, right? Right? Please, please be right.

They forgot to check staging, didn't they?

Because it's clearly working.

Yeah, if you build your game well, a lot of the APIs you expose for your gameplay team can be the same APIs you expose for modding. E.g., you need functionality to enumerate ships and get their SoI and orbital elements to display them on the map. Expose the same exact functionality to the modding API, and somebody can write a quick little plugin to show these ships on a separate map, just like in the image above. And scripting would be nice, but I hope it's a sort of thing we get as an option. As discussed elsewhere, a visual programming language would be a great way to get custom parts onto Steam Workshop without having to do a lot of extra work to make it safe. Plus, it might be more accessible to some people to start making mods. But at the same time, I hope it's not a replacement for plugin system. There is a lot you can do with plugins that would be difficult or impossible with a script. A plugin can talk to additional hardware, grab from or post things to internet, etc. That's what makes plugins less secure, but also so much more powerful. That said, it's still a unity game. Even if all we get is a simple VPL scripting and no other mod support, you can hack in plugin support with a custom loader. It's just going to be more work for the community to figure it all out and maintain it for version changes.

Not even a little. But it's the worst case scenario, as there is more mass around the edges, and if the aerodynamic force is applied at the center, it's more likely to break the plate. So all I am saying is that worst case scenario was enough to fracture the plate even if it was completely intact after the blast. Best case scenario is even load and the plate will easily depart the planet for good if it had at least 38km/s to start with. ( 11km/s * sqrt(10900kg / 900kg) ) There is still a question of whether the plate really was intact(ish) on that one frame, or if it was just a fine spray of shrapnel that hasn't had time to disperse yet. If the speed was, indeed, on the high end of the possible range and condition of plate was anything better than fine spray, I'm pretty sure at least some shrapnel was launched into interplanetary space. But I have no special confidence in either of these two conditions based on everything I was able to find. So *shrug*.

I also felt like I saw it somewhere, but yeah, maybe it was just an artistic rendering of what it would have looked like... So the problem is that I can't imagine the picture would be clean enough for you to tell any features. I don't think you'd be able to tell an intact plate, from pile of shrapnel or effectively metallic spray that hasn't dispersed yet. So while yes, the fact that it looked plate-like rather than an expanding bubble suggests that the shock was mostly flat, which I'd expect from anything arriving via a long shaft, it's not enough for me to conclude that it was actually intact. And again, size of shrapnel and velocity matter. If it was, indeed, on the high end of the estimate, in the 40-50km/s range, then unless the shrapnel was effectively a spray, these pieces would have punched through the atmosphere and only experience ill effects from that once in space departing Earth at escape velocity. In which case, I'd say launch counts, because nobody said it has to be an intact man-made object. But if the velocity was a lot lower or particle sizes really small, then the atmosphere would have created enough drag to slow these bits down enough to keep them here and, most likely, burn up.

Nothing X-Rays or evaporation of collimator do will have any impact on time scales involved. The only way a steel plate goes from rest to several (many?) km/s is due to arrival of the shock wave. It's the only thing that can give you these kinds of accelerations. And the way that works has nothing to do with shapes or material properties. The only thing that matters is density. A shock wave propagating in low density air hits high density steel. The shockwave is then reflected, and portion of the energy becomes kinetic energy of the plate as close to instant as mechanical interaction can get. Now, what happens next does matter on how the shockwave hit the plate. If it's a nice planar wave hitting a nice flat surface, the plate will depart completely intact. If the wave is uneven, there's enough energy there to turn that plate into a fine spray. I don't know nearly enough about geometry of the shaft, nature of explosion, and any number of additional parameters to even guess which one it'd be closer to. Btw, there seems to be a lot of misinformation flying about. I haven't found the original footage nor actual quote about velocity based on the footage. The 6x escape velocity was a rough estimate based on the shockwave propagation and was delivered before the footage was examined, and it's definitely an upper bound, not true velocity. The footage would place lower bound, and the actual velocity would be somewhere in between. I found a lot of citations claiming the cover was seen in one frame, but no other information that actually derives directly from that. Everyone seems to be conflating it with the 6x escape velocity upper bound.

You know, I was already thinking about it in terms of droplets, and increasing density due to water droplets themselves being dense, so I didn't even think about molecular mass, but turns out, that even with that taken into account, the low molecular mass of water is enough to offset it, making the net density inside the cloud lower than that of surrounding air. I guess, these droplets are a lot smaller than I have thought. Thank you for pointing this out. I'm going to go and add a bunch of strike-throughs in my post. XD

Not touching whether it actually departed intact at 66km/s. Going to take that as a fiat just to see what would happen. First, I would estimate how much speed is lost by the cover as it goes up. Absolutely worst case scenario at ludicrous speeds is if the object sweeps up all of the atmosphere. That's about 10T per square meter. In the mean time, the 4" steel plate is about 800kg per square meter. So the slowest the cover would be departing is at 18km/s. There is not enough matter between it and space to slow it down more. Notably, this applies to any fragments large enough that we can ignore viscous friction. At speeds as noted, just based on Reynolds numbers, it'd have to be in sub-mm sizes for that to be the case. Given that, the cover has to survive only a fraction of a second. So we can throw away immense heat, friction at boundary, or any turbulence as possible sources of destruction. The only thing that can possibly do damage in this situation is the decelerating force being uneven, causing inertia to tear up the plate. Again, the maximum force can't possibly change. It's just impulse of air being swept by the cover. In the most extreme case, we can say that the force drops to zero at the edge. So lets take this now to be a disk 120cm in diameter that's sweeping 1.2kg/m3 of air at the center and experiences no drag at the circumference. So lets convert it into static weight. The pressure at the center works out to a peak pressure P = 5.2GPa. Of course, we don't care about the absolute, but rather the gradient. About the worst case scenario here is if the pressure drops linearly to the edges. That will generate the most stress. Anything realistic will drop off sharper near the edge resulting in less stress. Take a ring of metal dr thick some distance r from center. It experiences aerodynamic force element: dF = 2π P (1 - r/R) r dr So total force up to some distance r: F(r) = π P (r2 - 2r3/(3R)) Notably, F(R) = (1/3) πR2 P = ma = πR2 d ρ a for the disk of thickness d and density ρ. So we have net deceleration: a = P / (3 d ρ) Stress is then computed based on difference between aerodynamic and inertial forces. ΔF(r) = F(r) - πr2 d ρ a = (2/3) π P (r2 - r3/R) S(r) = ΔF(r) / (2πr d) = (1/3) P (r - r2/R) / d And finally, Smax = S(R/2), so we can do the final analysis. Smax = (1/6) P R/d And since R/d for this disk is about 5.9, this actually works out very close to the same 5.2GPa of the peak aerodynamic force in the center of the disk. (It was always going to be a constant multiple of that based on geometry, but it being very close to 1 is just coincidental.) This exceeds ultimate strength of steel by a factor ranging between "a few" and more than order of magnitude, depending on type of steel. Add to that the fact that most of this is actually going to be sheer, not tensile stress, and the fact that the cover is going to be heated up by the shockwave passing through it, and I don't think it has much chance under the worst case scenario. So my money would be on the disk not remaining intact. At the same time, this is not something that tears the disk apart atom by atom. It's more like taking a compact disk and spinning it up to speeds where centrifugal force rips it apart, causing it to separate into multiple shards. Individual shards will have a far better chance of surviving the stress, as that R/d value is going to drop dramatically and air will be able to flow around the edges far easier. At the same time, there is still just so much matter between the shrapnel and space. That final speed of 18km/s isn't going to change unless shrapnel becomes small enough for viscous forces to take over, which would require very small fragments, on the order of no more than a few cm accross. So if the disk wasn't pulverized by the shock, wasn't heated to a temperature where it's effectively a liquid, and did in fact gain 66km/s (which are all HUGE ifs,) I would bet on some amount of metal shrapnel a few cm in diameter to make it through the atmosphere heading out above the escape velocity. But almost certainly not an intact disk in any case.

Well, ok, if we're having a real talk, clouds actually affect aircraft quite a bit. Not so much because of what the clouds are made of, of course, but because of what makes the clouds. First of all, there is humidity. It's at 100% by definition, and because tiny droplets do contribute to the dynamics at the scale of aircraft, the effective humidity can actually go a lot higher. That has impact on performance. Humid air is denser, which is good for your wings, propeller, and compressor in the jet engine. You get more thrust and more lift when flying in humid air, all else being the same. (Just the opposite! Humid air is less dense, and even with droplets of condensation, net density inside the cloud is lower. So less lift, less propulsion overall. Bad times. Thanks to @Jacke for correction.) On the other hand Moreover, humid air contains less oxygen by weight, so the engines that rely on external air for aspiration are going to perform worse. It's not a huge change, and for gameplay purposes can probably be ignored, but it actually makes an impact on fuel estimates and navigation by dead reckoning. If you are flying through clouds, you should be taking it into account. But it also gets a lot worse in freezing temperatures. If your airplane is coming down from high altitude through a cloud that's near or at freezing point, you're getting iced. The worst part about it is that you might not have had any problems on the way up, while the plane was warm and your engine was running full power, nor at altitudes, where the air was dry. So if you didn't think to turn on heat for your pitot tubes and carb, you can be in a lot of trouble. Landing with a dead engine, no air speed indicator, and at risk of losing some of your control surfaces to ice formation, is on a short list of worst things that can happen to your aircraft while flying. Second factor is more drastic and actually impacts rockets. There are a bunch of ways clouds can form, but usually it involves cold air meeting humid air. And if you have interface between two fluids with different properties, odds are good that you are getting turbulence along the interface. This one, I'm sure, many people who have been on an airplanes have experienced. When the plane is just taking off or coming in for landing and has to pass through clouds, and especially if they are big fluffy kind, you can almost bet it's going to feel like driving on cobblestones. It's no picnic for a pilot, either, as this means constantly having to correct the controls if you want to keep the plane on course, while also having no visibility and having to do all of that solely by instruments. And this is the kind of stuff that will matter not only to airplanes, but to a rocket heading out to space as well. In fact, to a rocket, turbulence can be far more destructive. From gameplay perspective, I think KSP is the wrong type of game to make you worried about all of that. But it'd be nice to have turbulence be a factor when flying through certain kinds of clouds. Nothing too drastic, just having it mess with controls a bit would be fine.

I know they've added some plants to Kerbin lately in KSP, and in KSP2 we've seen entire forests and can only guess what the biodiversity on other worlds will be like, but my brain is still stuck in the olden days, when the only living thing in KSP was Kerbals. I just wanted you to have context.