K^2

Same problem as with entanglement. There appears to be FTL action, but once you consider actual communication, you see that you cannot actually send a message across. In a nutshell, if you have long distance, then the barrier serves as a very fine energy filter. Anything with energy above the barrier will travel at sub-light speeds. Things that are well bellow barrier energy will decay exponentially at a rate which makes the exit amplitude zero. And only part of your signal that's juuust right will make it through. And once you've filtered just one energy, you run into the Heisenberg uncertainty problem. Effectively, the part that made it across "faster than light" was the part that was that delocolized to begin with. And if you consider things that are already delocolized that much, you just get noise from absolutely everything. There have been a number of articles trying to formalize this and show that communication under barrier is not actually possible as a theorem. Unfortunately, math gets really hairy when you try to make it a formal, absolute statement. At very least, I've never seen anything remotely as dry and cut as the entanglement no-communication theorem.

So wait, we agree that it's technically a correct name. But then you complain that the problem is with Physicists trying to oversell things with cool names. And I agree that it is a problem sometimes with some names. But if it does what it says on the tin, is it our problem that some people have unreasonable expectations? Our naming scheme shouldn't depend on what a lay person thinks of it. It should be based on whether or not it describes what something does. And quantum teleportation describes what it does. The quantum state is not carried across via any quantum channel, but is taken directly from one location to another. There is no way to describe it other than as teleportation.

All mater is just quantum states of the vacuum, plus a few conserved quantities, like total angular momentum and energy, that you will need to supply on receiving end. So while we are quite limited in what we can do with it yet, this is true teleportation.

What's wrong with quantum teleportation? Teleportation does not imply instantaneous transportation. Even in sci-fi, it is frequently light speed limited. It only needs to be instantaneous from perspective of whatever's being teleported, and quantum teleportation is that.

Exactly. There are theorems in QM to state as much. But entanglement might be an important element of a different scheme that would allow FTL, similar to how we use entanglement for teleportation. It gets a little complicated with frames of reference, but ultimately, yes. FTL and time travel are equivalent.

Heh. Just got my computer hooked up at the new place a couple of days ago. I was posting from the phone before then. I'll see if I have time to set it up today or tomorrow.

Mazon Del, I didn't realize cellular information was useful. We have cellular biologists in spades at my old Uni. I'm a co-author with a professor who specifically specializes in cellular microscopy. I'll get some info on what we can use that's light and small. Naturally. But the fact that shaded growth is of interest is great insight. This presents additional opportunities. If O2 is going to prove limiting factor, we can probably split the chamber, and have a secondary growth exposed to light, just to provide the oxygen for primary experiment. But it all depends on how long it'd take moss to burn through the supply. We should do some 1G runs planetside to establish how long moss can survive completely sealed with no sunlight, and how much we can extend this by having a split chamber. Anyone feels like growing some moss? Excellent. And again, goes to above. We need someone to start experimenting with growing stuff. Tricky, but since we probably want to have pressure control, both to be able to vent excess and to compensate for leaks, we should try for this. This is something they can do at ISS, however, without any expensive equipment, so it's definitely a secondary experiment. I'll work on getting a good sensor list and look into microscopy.

That would simply be a phased array. Not laser. I believe, sonic equivalent of laser has been demonstrated in solids, using phonons. Everything else is complicated. To have a laser, you must have a system that can emit or absorb a photon, and have it placed in an inverted population state. This might work with gravity. A field of rotating masses might... gase? But I do not know how strong the effect will be. States involved are not metastable and much too macroscopic. Other fundamental bosons are even trickier. Gluons are color-charged, and so are confined. If gluon laser could work, it would have to be in quark-gluom plasma environment. Weak bosons would make good candidates. Anything that decays via weak mode only is already metastable for that very reason. Inverted population is a given, since ground state is vacuum. The trouble is getting enough of such matter together to observe effect. And the fact that once strong forces take over, you will have a major gamma release event.

That's a strange way of saying what I think you're saying. But yes, the situations in which you could actually make practical use of black hole gravity assist are bound to be rare. On the other hand, if we're talking about using black holes for boosts, we probably aren't talking about things on scale of a star system. There are plenty of black holes going around with the other stars in our galaxy, and these can still be used for significant boosts. One of the limiting factors of boosts from planets or even stars is that there is only so much angle change you can get without hitting the thing. With black holes, that limitation does not exist. Your trajectory can have any exit angle you like. Just watch out for tidal forces.

There are definitely more options for FTL comms than FTL flight. So statistically, a bet on FTL communications is slightly more likely to eventually pay out. Not any time soon, though. Keep in mind, most of the least-unlikely options are basically time machines with FTL comms being an obvious side effect. That does put it into perspective. For example, of Kerr interior solution was right, and fire wall hypothesis wrong, it should be possible to set up a quantum teleportation algorithm to pull information out of a black hole before it goes in. Yeah, it's gross violation of cosmic censor, among other things, but since it's a classical field theory conjecture, I don't see why it necessarily have to hold when we involve quantum fields. Other methods have similarly absurd requirements. All in all, warp might still be our best option. And creating microscopic quantum warp bubbles for sending information might be more feasible than building warp ships. The down side is that we lack a lot more of the theory on how-to. P.S. There are some purely stat-mech thoughts on doing local time reversals, some of which have been experimentally realized, but arrow of time is ridiculously persistent. There might be some quantum trick for pushing information through these against normal time flow, but even if it works, the time span would be measured in minutes, if not seconds. Not very useful for communications, but plenty useful for many other things.

I'll do some estimates. I think, we should have enough excess power on the day side to power a thermocouple heat pump, which would let us get rid of waste heat easily enough. (There are units designed for CPU cooling, which should be just about right in terms of power output and delta-T.) On the night side, cooling can be passive. All in all, I'm pretty sure we can maintain a +/- 5 degrees environment, which might not be ideal, but should be sufficient.

Whoever started that horrible public misconception that Higgs is the cause of mass deserves public lashing. It has nothing to do with mass of most things. Certainly, not even close to main contribution in matter. By far, most of the mass is generated dynamically and would be the same without Higgs.

Area is irrelevant. It is effectively a problem of field from infinite plane, as above. Which produces miniscule gravity at any sane density. However, it also calls for zero gravity half way down, and negative above! I would, therefore, conclude that the source of gravity in MC world is in the Void, if not the Void itself.

Hawking makes a lot of exaggerated claims that should come with a novella-worth of foot notes. Predicting what happens at these energies to vacuum is far beyond the methods we have. We cannot even estimate zero point energy properly. So this prediction, if anything, tells you how weak the model is. And without better context, it is hard to say that this was not his point to begin with.

Good points. I would vote for that.

Two main problems. First is the gas exchange. As people who have kept aquariums will tell you, simply having contact with air is not generally enough if you'll have aquarium densely populated. We'll either have to agitate the surface, or pump liquid through membranes to set up high exchange rate. Tricky. Second is stability. Once spinning at constant rate, it's not really an issue. But during spin-up or attitude adjustments, the currents will be hard to predict, and will throw off overall moment of inertia. That can result in an axis tumble, and that's all sorts of trouble. Wouldn't be an issue with high torque reaction wheels/rockets, but magnetotorquers will not give us enough torque to counter this. I would like to avoid something that unpredictable and that likely to cause total loss. Nicholander, Java Moss, since it is strictly aquatic. High humidity isn't an issue if needed, but anything that requires to be fully submerged is problematic.

The only trouble is that it seems to require liquid water for its medium. Which might make things a bit complicated. I would definitely like to learn more about other options we have. Which, again, requires a good biologist/botanist. I just don't know any, other than these specializing in single cell organisms.

It's not so much that Universe "doesn't care" about our math problems. It's more the case that our math problems usually indicate that things aren't as simple. For example, elementary particles are also point objects. They also have infinite density, and should result in all the same problems. But, fortunately, they don't obey laws of classical mechanics, but rather these of quantum field theory. Same goes for black holes. There are a number of "divide by zero" problems with both singularity itself and the event horizon. And everything we've learned so far points to these problems being resolved in proper quantum gravity model. Shame we don't have one in which we can actually compute anything useful at these scales. But maybe some day.

It'd be quite trivial, for any foreseeable mode of travel, to simply use signals from a chosen distant pulsar to keep track of "universal" time. Naturally, moving closer to the pulsar would advance time, and vice versa. But we can either correct for that knowing the distance, or simply deal with it like we do with time zones.

Precisely that. The ISS orbit would still give us about half a year to a year, depending on how much drag we get from solar panels, which should be more than enough. I have a feeling something else will go sideways well before the re-entry, anyhow.

Mars might be a bit much... But in any case, the rate of rotation will be adjusted with magnetotorquers.

Hopefully, we'll be able to measure temperature, humidity, pressure, and either O2 or CO2 concentration. With some basic assumptions based on what goes in, we can pretty much get full atmo composition from that and how much of what is being consumed. This, indirectly, lets us monitor biomass growth. So long as nothing goes fubar, that's useful data. I don't know how practical it would be, but apparently, there is some interest in it. Additionally, we can snap some pictures. Though, I suspect, these will be primarily to satisfy curiosity.

You cannot have a rigid body rotating on 3 axes. At any given moment, body rotates about only one axis. The axis of rotation. However, if that axis does not align with one of principal axes of the body, the rotation axis will tumble. You can sort of think of the resulting precession as rotation about two different axes. And even that is pushing it. 3 is right out. So as far as motion goes, the astronaut is going to move along the same trajectory as a point on the station that he's attached to. Presumably, his mass doesn't affect the inertia tensor much, so he'll be moving along the same exact trajectory that the point was moving on before he grabbed it. However, as outlined above, due to axis tumbling, that trajectory can be quite complicated.

Careful with that. We don't know how Squad feel about all of this, and fair use only goes so far. The fact that none of this is for profit makes a lot of legal hoops that much more manageable, but they can still claim damages. As a KSP community, we can get away with referring to this as a KSP-related project, so long as all of the disclaimers of non-affiliation are in place. But use of trademarks and IP, such as KSP logo and Kerbals, is a very shaky ground. And that's just based on US law. I don't want to even think of what sort of copyright gremlins Brazilian law might be hiding. Better stay safe for the moment, and keep any KSP stuff to the minimum.

I don't know if this is over-simplified or very outdated, but strong nuclear force is not simply due to meson exchange. For starters, the way that meson interacts with a nucleon is via strong force. While meson exchange plays a role in nuclear interactions, what we actually call a strong force is due to guon exchange.