K^2

Description of warp drive is very shaky, but it's on the right track. Unfortunately, we only have warp capabilities on paper so far. So no FTL ships used by our (or anyone else's) gov't. Stealth tech isn't as far along, either. There are metamaterials that can bend light as described, but nobody figured out how to build them into an armor yet. They have some properties that don't make them suitable for construction. On medical, we can't print something like a replacement arm yet, but we're really close on that. So that one's almost believable. The rest are nonsense.

Liquid is only going to provide self-balancing effect if certain conditions are met. If you model your system as a damped harmonic oscillator, there is going to be a phase angle between direction of centrifugal force and deflection. If the natural frequency is higher than your 2,400 RPM, the angle is small, and the effect is destabilizing. If natural frequency is low compared to the angular velocity at which system is spinning, the angle tends to 180°, and it becomes self-balancing. So it's entirely possible that your system is too stiff, preventing self-balancing. The other question is purely on the ability of glass to withstand this kind of abuse. At 5cm and 2,400 RPM, you'd pick up something like 300G. Are you sure the glass you are using is designed to handle this?

It clearly is rotating around center of mass. Please, leave physics to people who actually understand it.

Sounds good to me. If you make good quality video, I can write a small program that tracks the dot from the laser on the frames, and does statistics on this position.

Interesting. I guess, I shouldn't over-rely on Greek and Latin roots being distinct. Thank you for the correction.

In Russian, the word "Cosmos" (ÚþÑÂüþÑÂ) is primarily used to mean outer space. It can also mean actual cosmos, but that requires context. So while we all sail through the cosmos, and in English, the term "Cosmonaut" seems to be a bit redundant, in Russian, it makes perfect sense to call people who fly space ships "Cosmonauts". From perspective of word formation, though, "Astronaut" is a bit more consistent, since both roots are taken from Latin. "Cosmos", in contrast, is a Greek word.

If you understand something about conservation of momentum and impulse, it's the same thing. Also, impossible. Time average of the net force on supports equals to the total weight of the supported system. Again, it's a consequence of some trully fundamental principles related to local symmetries.

Except in immediate proximity of the singularity, it would have the same effect as any other object of the same mass.

Z-Man is, most likely, correct. Gyros being off can also offset the phases at which normal forces on wheels/rails and longitudinal forces peak. By the way, concept of "gyroscopic oars" can be worked out on paper completely using basic mechanics to show that it a) does behave in some odd ways, but does not produce any net force. If you want to avoid confirmation bias, you really ought to formulate your hypothesis better before jumping into experiment.

If it had any significant mass to begin with, evaporation ends in a pretty powerful explosion, as the rate at which it increases energy gets exponentially higher as it shrinks. There is absolutely no reason to suspect that evaporation halts, or even slows down, at a certain size.

That's not strictly true. Looking at thing like impedance and conductivity as complex values helps, of course, but you can do everything in electricity and electrodynamics using real values only. This might be what you were going for, but it seemed to require clarification.

Erm, sort of, but not exactly. Group of unit quaternions is homomorphic to SO(3). In layman's terms, every unit quaternion can have a rotation assigned to it. Taking a product of these quaternions is like applying rotations one after another. That's the connection to real world. But you don't have to go this far. Group of unit complex numbers is isomorphic to the SO(2) group. In other words, every rotation in 2D can be described with just a complex number. And we know that you can combine 3 2D rotations to form a 3D rotation via Euler's Angles. That's your connection between complex numbers and quaternions. (I'm oversimplifying that last bit a hell of a lot, but it illustrates the point, I hope.) Completely unrelated topics.

That would probably be static vs kinetic friction. Again, similar to violin string. This is a subtler effect, though, so I'm sure amount of motion you get out of that isn't as significant as from normal operation.

Wouldn't be the first time. It's a good way to build a simple mechanism fast. Only trouble is that all of my Legos stayed in storage at my parents' house. Fortunately, I was planning to drive to visit them tomorrow, anyways, so I'll be able to grab what I need, or just build it right there. I just hope I can get the right gear ratios. I need 2:1 to make this work right. Nah. His English is way, way better, and he doesn't seem anywhere near as crazy.

*sigh* Get on an office chair. Do a sharp move to the side. If you do it right, you can move across the floor. But the wheels roll the same in any direction, don't they? Well, yes, they do. But it's not just about direction. There are two types of friction, static and kinetic. Static friction is stronger than kinetic. Ever wondered how violin strings work? I suggest you look it up. Strength of the friction force also depends on the normal force. Try to slide a carpet across the floor. Now try it with a person standing on the carpet. See where I'm going with this? Your rig twists and wobbles. When the board tries to twist in recoil to motion of the weights, rail prevents it from doing so. Same deal with the wheels, though, it's sideways motion that has bigger impact there. Whenever that happens, normal force increases dramatically. So the amount of friction your rig has is time dependent. If you now have something rocking forward and back, as you do, if the forward motion of your weights matches the twist timing, the friction force prevents the whole board from recoiling. But as the weights are drawn back, the normal force is much smaller, allowing the board to accelerate. This is a very simple effect. I can build a demonstration rig that proves the concept out of Legos. If it gets you to stop claiming silly things, I'll go ahead and build it.

Take an estimate. It doesn't have to be precise. There is enough on the video to get it within an order of magnitude. Go for it. It will tell you how silly this idea is. And since you mentioned it, for bonus points, go ahead and calculate the centripetal force required to keep a typical hurricane spinning. You'll find that it's also a rather small number. If you want, you can also try and tackle radial pressure gradients and the way velocity changes. You can actually get a very good approximate model for a hurricane without knowing any hydrodynamics by assuming an inviscid flow.

Friction makes it move. And your experiments only serve to demonstrate that. I've told you how you can convince yourself that it is so. The fact that you haven't done that yet doesn't mean "we don't know." It means that you are confused and you need to get on with un-confusing yourself. That's just silly. If you were able to calculate, you'd realize how laughable that amount of force is.

Predictions of field theory partially verified with experiment aren't good enough for you?

Before making claims like that, it helps to learn a bit of actual science. In this case, about friction and normal forces. Your "frictionless" setup actually has a lot of friction. To test this, I recommend you stand on that board and have someone pull you with a force sensor. Yeah, the thing glides pretty well with no other force applied, but that's the whole point about normal forces. Your setup twists all over the place as it tries to move, which can apply a significant amount of normal force, comparable to that of a person standing on the board, easily. Yet, the amount of force it needs to propel itself is minimal. You add these together. If you actually want a nearly frictionless setup to test this with, use a long rope to suspend your apparatus. A device capable of generating thrust will be able to maintain a deflection angle. I don't care if it wobbles all over the place, that's fine. But its average position needs to be deflected. And your setup won't do that. It will just shake itself silly.

There would have to be a fundamental anisotropy to the space-time. Since that anisotropy would be detectable, there would be a preferred coordinate system. In other words, there would be such a thing as an absolute velocity. If that anisotropy would be periodic, momentum would be replaced by quasi-momentum, similar to that of free particles in a crystal lattice. If the anisotropy is amorphous, there would be no such thing as momentum conservation at all, and a closed system would be able to propel itself. Three would be no gravity. At least, not in a form we understand it to be. There could be any number of gravity-like forces related to structure of space-time itself, rather than accumulation of matter. Other fields could still work. But their strengths would change with location, making any complex life impossible for any practical purposes. In fact, organization of any kind is difficult to imagine.

No. There isn't. Gravity is caused by the local Poincare Symmetry of Space-Time. By Noether's Theorem, the conserved charge of that symmetry is stress energy tensor. Among other things, it gives you momentum conservation. Topological charge conservation is the most fundamental thing there is. It's the source of, well, everything. And that's the thing you want to disregard, or violate, or cheat. It just doesn't work that way. It's possible to move without thrust. There is teleportation, warp drives, and wormholes. And these are the realistic options in comparison. But getting thrust without reaction mass is simply not possible.

This actually makes me wonder if it's absolutely impossible under all circumstances. I seem to recall that a particularly fast asteroid can generate significantly more energy on entering atmosphere than it carries in kinetic energy due to atmosphere undergoing fusion. Ok, yes, at this point we aren't talking about a re-entering ship, because lets face it, this is not a survivable scenario. And yet, there is a definite surplus of energy, and not an insignificant one. So the question is, is it possible in principle, for an asteroid to hit atmosphere just right, generate massive explosion in atmosphere, and for some of the fragments to leave at higher velocity than they came in at. And again, I realize that in order to be anywhere close, the thing already has to move at much faster than escape velocity, so this isn't about skipping to escape. Just about gaining velocity via "aerobraking".

The rocket should be coasting at good speed at that time, allowing aerodynamic stabilization. If it's not, then you've messed something up in terms of engines you've selected for your rocket.

Heat flow in a gas is a very complicated question. First, it does emit/absorb the IR, but not equally well at all frequencies. You need to consider the absorption spectrum. Radiation spectrum will depend on that and the temperature. Besides radiation, heat also propagates through gases (or fluid) via advection (or convection) and heat flow. You can basically assume that boundary layer of gas (fluid) touching your solid object has the same temperature as object's surface. Through the solid, you only have to worry about heat flow, so you just need to know heat conductivity of the material. Then you can solve for temperature gradient and figure out how heat flows through the solid. In the gas, you'll have heat carried by both the movement of individual molecules, which is going to work like diffusion, meaning it follows the same laws as heat propagation in solids, but also carried by the gas flow. If you know the flow rate, this is pretty straight forward to figure. Unfortunately, in a lot of cases, the flow depends on how much heat is carried away. Hot air balloon is a good example. As you've pointed out, making skin of the balloon reflective minimizes IR losses. But heat will flow through the skin, heating up surrounding air. As the surrounding air heats up, it will rise, generating a convection current. That will carry away the heat and bring in fresh cold air. That means more heat will escape, and that means a stronger convection current. In order to figure out exactly how much heat you are going to be losing, you need to solve a complicated hydrodynamics problem along with the basic heat transfer problem for the balloon's skin. So if you are looking for a simple solution from perspective of theory, there is none. It might be possible to come up with an approximate analytical solution for a simple shape of the balloon, but for a general balloon, this would have to be simulated on the computer. There might be some empirical, very roughly approximate formulas out there. I am not familiar with anything like that, but it seems that for balloon sport, this might have been useful, and somebody would derive approximate formulas based on observation. Try searching the internet, or maybe find an air balloon forum if you need a formula specifically for that. If it's more general, like I said, it's going to be a very complicated computation.

It's very easy to make an orbit-matching maneuver, and I could walk you through equations. But for rendezvous, you need to match orbit and time. (In terms of orbital elements, your anomalies must match. In fact, all orbital parameters must match, but that's the tricky one.) I am not aware of any method of doing this that does not rely on iterative methods. Are you trying to understand this, or are you just looking for a quick tool? I can probably write a script that gives you a good (not necessarily the best) transfer for rendezvous, if that's all you need. You can also try to figure out what the code does to understand this better.