Mazon Del

I actually almost worked for those guys a bit. Liftport is a pretty cool group.

Alright, compiled what seems to be a quick list of the questions people had for me. Henryasia: (PS Mazon Del, if you're reading this, I still think 1U will make a gravity gradient in the experiment big enough to mess with our data, what's your take on that?) Yeah I've been wondering about it, but it seems mostly that as long as we have a spread of the moss across the enclosed area in question, that we should be fine. We are trying to see how extreme the gravitometric response is, so as long as its growing (even if in funky directions) then we can see what we need to. We can always do some analysis based on the mosses position to determine what their gradient was like. Henryasia: On the other hand, Mason Del could definitely get some samples like, right now, film them in the dark under IR light at 30 FPS (or whatever an IR camera can do) for some days, then we'll speed up the video at different rates and see which one is acceptable for growth analysis. What do you say? I highly doubt we need anything beyond an image per hour. I can check with Luis and see what he thinks, but I'd guess that the response is going to end up being that one image every 4-6 hours is more than enough. However, a point to consider here. If we are carrying up multiple moss capsules (they are only going to be a couple centimeters or so to a side), then 1 image every 6 hours could end up meaning 30+ images per 6 hours. Because we'd ideally want to be imaging each set of moss. And this doesn't take into account the possibility that we may desire a different camera angle. Henryasia: PS: Dammit! SpinSat is taken! MossSat, anyone? I vote we name it KossSat. K because Kerbal, oss because moss, Sat because satellite. I further vote then that our mascot should be a Kerbal wearing a traditional Cossack outfit. K^2: So long as we are getting clean readings from all of the sensors, we should still be able to estimate biomass growth pretty reliably. Caring about the biomass growth is only part of the data we want. We are caring about the gravitometric response of the moss (its tendancy to grow away from gravity [up], towards gravity [down], and perpendicular to gravity [sideways]) based on how they have been bred. We can only determine this based off of image data. The reason we care about the gravitometric response (to those just joining us) is that it gives is a good idea about how the plant cells react under the different gravities. If the plant reacts poorly to the 0.1Gs, but grows well in 0.3Gs, then this tells us that the optimum G load for the plants to be under when cultivated in space and when you don't want to go through the expense of a full 1G rotation system is somewhere above 0.1Gs. It will also provide us with information about the behavior of plants in such conditions, useful if you intend to grow plants in a rotating drum like this. Extra: So some thoughts I've been having about the internal camera system. Assuming we are going with several moss capsules, the camera IS going to have to move if we want close up shots (or if we want microscope shots depending on camera). So, given that, the idea that I have is that in the center of the growth chamber exactly on/aligned with the axis of rotation is a pole. This pole can rotate either 180 or 360 (depending on if we have one or two cameras). Extending out from this would be a bar that has the camera on its tip. We can control the rotation of the bar and its position along the axis of the pole. The way I would implement this is for the pole to be a tube, and the tube has a 2 slits going down through it on opposite sides of the pole. Inside (but not touching the tube) is a threaded rod. One motor controls the rotation of the slit-rod the other controls the threaded rod. The arm for the camera/microscope has a nut at the center which has been threaded onto the rod. You control height by having the tube hold still and rotating the threaded rod (its like screwing/unscrewing something) if the tube holds still, this means that the threaded rod is rotating but the arm cannot, so the arm will raise or lower. Conversely, if you hold the rod still and you rotate the tube you get a rotation. This rotation WILL influence your height, but I've already explained how to adjust that. It is a compact design that isn't very complicated. Whatever happens to the camera will happen to the fake camera-like weight on the other end, or also to that camera (if we have two).

What it likely does for you is lets your missiles be less accurate, but still have a chance at hitting the target. They just get in range, point in the right direction, hope for the best. A bit like the Honor Harrington laser warheads.

EzinX: The main reason why the Q-Thruster (still, assuming it works, really really want it to work...) ends up being better then VASIMR despite their similar thrust/weight ratios and such, is simply that the ship using a Q-Thruster no longer has fuel concerns. Which means that the act of forcing them to dodge means nothing except that it will take them slightly longer to reach their target. I'm assuming the ship in question of course has something like a nuclear reactor. Effectively fuel-less for 10+ years of operation. As a result, most of the text in my giant wall of it previously is meaningless. The tactics laid out there depend on the idea of forcing your enemy to waste enough fuel such that they are either unable or unwilling to complete their mission (completing it could mean the crew ends up in a solar orbit far away from help with not enough fuel to reach anywhere that they could even surrender at). The second aspect of the tactics still ends up being decently valid, as it is easier to heat up the ship with what amounts to a flashlight beam from a maser than it is to hit it with a railgun round, eventually the crew will succumb if not the hardware. As far as what I was saying about coolant. I wasn't actually stating to dump coolant itself, I was stating to dump FUEL, utilizing it as a coolant. If your fuel source is anything cryogenic or volatile at elevated (but not extreme) temperatures, then as the ship heats up you are going to be boiling some off and will have to vent the excess to prevent the pressure in the fuel tank from reaching dangerous levels. Since you have to do this anyway, I was saying you might as well use it in some way that lets the escaping fuel take more heat with it. The liquid droplet cooling system I have always somewhat enjoyed as a concept, but it has some issues, especially for a warship. Passed a certain phase in the combat, the warship is likely going to be relatively constantly changing vector and orientation. Unless you contain the droplets in some sort of physical tube (which I imagine would drastically reduce the effectiveness of the system, even if IR transparent) any time you turn or shift 'position' you'd be losing the droplets. Of course the way to ensure you don't lose any is by turning the flow off, sucking up the rest, then continuing. Depending on how long this process takes, it could result in a net gain of thermal energy rather than a net loss. Remember, the other guy is presumably looking for any situation where you are 'standing still' to focus all of his lasers on you for maximum heating. Additionally, I would assume that you could only really utilize the droplet booms on the opposite side of your ship from the enemy. Either their beams will heat up the droplets instead of letting them cool (in which case collecting them gives you heat) or they simply reduce the effectiveness of the droplets (in which case, nevermind, go ahead and do them). Earlier in your post you mention that the acceleration provided by the Q-Thruster in your math is about 0.33% of 1 G of accel. That is perfectly fine for dodging the slow stuff (railguns, missiles, etc) over combat distances of thousands of kilometers or larger (the larger the better of course). Terminal changes though (quick turns/translations to dodge incoming missiles and close railguns and eventual laser fire) it might behoove your ship to have something that can do quick bursts even at the expense of having an expendable fuel. But the Q-Thruster still provides you with the game changing fuel-less main engine. Remember, the idea of making the enemy waste his fuel is only really helpful if it means he won't end up getting anywhere he wants to go without it. If all you do is reduce his maneuverability, this was still helpful but his mission is still possible.

I enjoy this topic for a lot of reasons, so I figured I'd toss in my side of things. In a space fight, you want one of two things. The enemy destroyed, or the enemy incapable of performing their mission. These two are not necessarily the same thing, but are equally as effective. Supposition 1: The craft in question has a limited amount of fuel. Supposition 2: The craft has enough fuel to make it from a starting orbit around its home, to the target planet/moon/etc, enter an orbit around said target, return home, orbit home, some extra amount for maneuvering/fighting. Supposition 3: Standard drive technologies in use (basically chemical, NERVA, ION, whatever. But no Q-Thruster type systems. [Enjoy that Kerikbalm ]) Supposition 4: Head radiating ("cooling") technology works roughly as well as it does now. Supposition 5: The craft will be manned. Supposition 6: Both sides know the fight is coming or are already at war. IE: No surprise attacks. Supposition 7: Both sides have multiple ships. Supposition 8: Excluding when part of a fleet or in orbit near an inhabited location, a ship without engines will be unlikely to receive aid. Given these 8 suppositions and a basic understanding of physics one can extrapolate out a great many things about the ships. Extrapolation 1: Bigger ships will require more fuel to accelerate/maneuver to the same degree as smaller ships. Extrapolation 2: The greater the physical requirements of the weapons, the greater the ship will mass. Extrapolation 3: Ships will generally require engines capable of endurance burns (planet to planet travel), but also burst burns ('dodging'). Extrapolation 4: The direction that projects the maximum firepower of a ship will also present a minimum of risk to the engines. Extrapolation 5: The direction that projects the maximum firepower will endeavor to minimize the visible footprint of the ship. Extrapolation 6: To some extent the ship will provide protection to the engines from the side. Extrapolation 7: The fuel storage requires at least as much protection as the engines, preferably more. Extrapolation 8: The thermal radiators will require some level of protection. As a result of these extrapolations I believe it is fair to state that a likely warship design ends up being something resembling a cone (there are pros and cons for making this a longer or shorter cone) with a bit of a "bowl" area in the rear. The engine(s) will be largely embedded within the bowl area in the back, and the fuel storage will be in the center of the ship, just forward the engines. The main thermal radiators will likely be focused in the rear of the ship in either the main 'bowl' or in their own similar enclosures. Expendable/stowable radiators will be on the cone itself, minimizing footprint to enemy, but not impeding ship systems. The usual assortment of thrusters for orientation/dodging will exist on the hull, likely with several backups. If the ship is expected to be going on a heavy war footing, then there would additionally be hardpoints to mount 'disposable' systems. IE: Increased fuel, heavy missiles, possibly things like SRBs, all things that can/will be tossed once used up for mass reasons. There will be 1 forward facing engine, for specific instances requiring large reverse thrust. Reason 1: Any weapons on the outer surface of the cone can face forward, providing a maximum firepower orientation. Reason 2: With the cone pointed towards the target, a minimal footprint of the ship is presented (less area for the enemy to target). Reason 3: With the cone pointed towards the target, the maximum effective mass of the ship is between the enemy and the fuel/engine section. Reason 4: This shape presents an angled surface to the front and to perpendicular directions. Sloped armor provides additional defense from any hit not perpendicular to the slope. Reason 5: In the event that the tactic of rolling the ship is necessary (preventing a laser from holding its spot?), you are still presenting a sloped surface to physical munitions. Reason 6: In all but the most up-the-skirt style shots, the engine bell(s) are not exposed, indeed the shape of this location may provide a slight extra thrust boost as it could act as a larger bell. Reason 7: The thermal radiators will be protected and in cases where no risk of damage from the side exists, they could extend backwards to increase efficiency (less radiating onto the ship itself). Reason 8: More radiators is pretty much always going to be better than less (only mass/stealth [hah] constraints are really going to restrict these). Now onto weapon systems. The most likely load out for these ships is going to have a relatively heavy complement of lasers/masers, a few railguns (2 minimum for full coverage), a bay for a limited assortment of small missiles. Assuming the war footing mentioned, the ship would likely launch with several heavy missiles (3-5) attached the external hardpoints as well as some extra fuel tanks and a couple SRBs. In a scenario of a fight between say Mars and Earth, the ship assigned to defend Mars would likely utilize the SRBs alongside the main drive to get it the initial high thrust kick out of Mars orbit and on its way to intercept an attacking Earth ship. Once something approximating an intercept (at least insofar as the ships will be entering each others weapons ranges [note: YES railguns have a "range", this is determined by the dV they can impart on the shots. Not enough and they cannot reach their target's orbit.]) was assured the Mars ship's opening move is the launch of the external missiles. All fuel utilized by the ship will be from the drop-tanks. Detaching can happen to increase maneuverability, decrease footprint, or because they are empty. At this point I need to pause to explain the tactics of the Mars ship. Going back to the beginning, a destroyed ship cannot complete its mission. This is desirable. A ship can be made incapable of completing its mission without being destroyed. This is also desirable. If you can incapacitate the crew, the combat ability of the ship is vastly decreased, namely in that repairs cannot be made. If you can destroy the ships engines, then you have removed their primary method of changing vector. This LIKELY means that the crew is going to die. Without another ship capable of intercepting it physically to transport repair materials or to offload the crew, the ship will never change vector and will either hit something, or likely enter some abysmal solar orbit far from help. Additionally, if the ship cannot execute large vector changes, it becomes that much easier to target for eventual destruction. The same eventuality occurs if the fuel supply is lost or expended. The plan of the Martian ship is to force the Earth ship to maneuver itself into uselessness. Those missiles of yours will likely spread out a nice distance to both minimize the chances of being hit by the crossfire, but also to allow a greater chance that one of them will be in position to strike at the Earth ship. They will occasionally need to exert course changes in order to meet up with the Earth ship. The Earth ship has a choice, if it wants to, it can spend fuel dodging around in the hopes of forcing the missiles to waste too much of their fuel to allow for an intercept. Or, he can not care and just hope for the best. Note: The Earth ship has the advantage against the missiles. It knows the missiles want to hit it, so it knows where the missiles will try to put themselves. But the missiles don't know where the ship will try to put itself. Given this, the Earth ship can be imagined to have nigh-instant knowledge of what the missiles are doing and roughly when. If it shifts up, the missiles will need to shift up. Due to the light lag the missile has no way to tell if a 1 second up burn is going to stop at one second or not until that time has passed. If the Earth ship fires the main engines up for one second, then slams on the reverse engine (told you it would have a use) for 10 seconds, and the ships are at a range of 10 light seconds, it has executed a relatively massive vector change before the missiles even saw it happened. The missiles will begin reacting to the first burn before needing to react to the second. Meanwhile they don't know where the ship might be going to next. Now I can continue on the logic, counter logic, etc, of missile vs ship combat. But in the end the result is that the ship is going to be spending fuel, probably whole lots of it. Now those of you who favor missiles are probably asking what the point of the rest of the weapons are when you have those missiles. Remember, while your missiles are on their way, you don't really have much to do. Adding more missiles won't really change what is happening. More missiles only means that you can repeat this process after the first have hit or missed. But more missiles with useful amounts of dV means you get much heavier, and thus less capable of dodging the enemy and HIS missiles. Now, while the enemies ship is bandying around in its fuel based chess match with the missiles, it is time for the lasers to make an appearance. Your lasers are not designed to burn through the enemy ship, no, that is certainly silly at these ranges. Your lasers are simply designed to dump as much heat as possible into the enemy ship. Remember all those radiators? You need them because YOU will be generating quite a lot of heat firing these beams, but also because you are going to likely be hit BY the enemy beams as well. You both are going to be sitting there trying to cook each other. You have an advantage over your missiles. While you still have the same light lag as they do (worse, since they are approaching the enemy at a faster rate than you, they are closer at any given instance of time and thus have less lag to deal with), you have the advantage that the Earth ship cannot tell where you are positioning your shots. Oh, like with the missiles, he can assume that your beams are going to be bracketing his ship (say 40% across the forward arc, 30% across the rear arc, 10% incase he translates 'up' and 10% for 'down', and 10% straight at him. While you may or may not have 10 lasers to fire, this rough distribution is probably the best to start with if they are being particularly dodgy, but of course adjust as necessary), so it really doesn't matter much which way he picks, he'll run into your flash-light beams of heat and pick up some for himself. Now, this isn't totally a very efficient exchange rate of heat generated vs heat deposited. At this point in the combat, that is perfectly fine. The more heat he picks up from your lasers (especially from running the engine as well) the better. As he heats up, he is going to need some method of dumping the heat that is faster than just radiators (especially because any radiators you are managing to hit with your beams, are losing their efficiency). Assuming that the fuel of both ships in question ends up being not a monopropellant, then you are both going to do the same thing. You are going to flush your ships in fuel to boil off the heat. Let's assume you are both working with good old chemical rockets. Flush your radiators, engines, and weapons with some of that liquid/gaseous hydrogen and boil it off into space. Chances are the heat in your ship has been building up pressure in your fuel tanks, since you have to vent it anyway, might as well have it take as much heat as possible. Starting with those external tanks you might still have of course. The hydrogen isn't dangerous until it comes into contact with the oxygen. Which you will of course use "last" considering that if you'd lost life support, you'd rather have a bunch of extra oxygen than a bunch of hydrogen lying around. But once the fuel levels start getting unbalanced enough, switch over until they are equal again, then go back to hydrogen. Now what is this doing? Its making your enemy dump fuel! During this whole exercise, do not bother firing the railguns. They will generate heat you do not have the thermal budget for, for zero gain. The enemy ship is ALREADY dodging missiles (and technically your lasers), your railgun rounds are just going to miss and they get no utility out of causing him to waste extra fuel. This is because at the distances you are still fighting on, the Earth ship is not going to be anywhere near where you targeted the railgun rounds by the time they reach him. Bracketing him is worthless at these ranges since the necessary bracket size would have you quickly deplete your ammo stores. What you are going to want your railguns for at this point in time, is missile defense. You have the magic knowledge of where the missiles are going to be and what they are doing before the light of this event reaches you. Remember, they have to hit you, so they MUST react to you. You know what they have to do to hit you, so you can predict what they are doing. Sure they might not follow this prediction, but its a safe bet they will. In the end though, lets assume that all the missiles have missed or otherwise been destroyed. While you are still at these absurd ranges, the fight will stick mostly with the lasers. You will occasionally potshot at/around the Earth ship, but this is mostly just to verify his fears that he needs to occasionally burst just a tiny bit from his thrusters/engines to change position to dodge. More fuel waste. Meanwhile the whole time, you two are lazing each other, dumping fuel for heat purposes, and maybe executing a major dodge to get a couple seconds reprieve (if your engine's heat efficiency is that good). Eventually though, assuming one crew hasn't managed to broil the other alive yet or surrendered, the ships will enter into railgun range. Where the cost of bracketing the enemy ship isn't very high. Now is when any last trump cards you have for heat come into play. The closer range means both that the railguns matter a lot (if you hole their engine or fuel source, they are out), but that lasers will hit more accurately, but now everybody needs to use their engines to dodge. At this point its a grudgematch to the death, play all the games you want with rotating ships, beam/railgun sprays. The victor will be determined most likely by who entered with the larger capacity to suck more heat. If not, it was then determined mostly by luck of the draw. At this point you might ask why bother having those small missiles that I had mentioned earlier? Simply because there are some situations your warship might find itself in that lend itself towards missiles rather than railguns or lasers. These situations are generally speaking only when the ships are at obscenely close ranges for space ships, such as in the same orbit as each other. They likely wouldn't have the dV necessary to perform an intercept on an interplanetary intercept. Lets say you need a nuke for some reason, these missiles at least let you have that without the expense of a full on system missile. Now of course the whole darn thing changes if Q-Thrusters ARE real...no fuel requirements, absurd accelerations (and thus closing speeds), fuel-less missiles, etc.

Greetings everybody! Sorry about not responding to stuff. For the last 10 days or so I was on vacation, so I didn't access the forums much. I'll be reading through the last..10? pages of stuff and compiling a list of what I need to answer later today.

Here is what I have been doing with my hard dives. This will likely change soon though. I have been buying two high speed (7200+ RPM?) 2 TB drives from DIFFERENT manufacturers, and setting them up as mirrors of each other (one goes down, the other still has a copy of the data, the different manufacturers increases the chance that if one fails, the other isn't minutes behind it). But I only use this setup as the data storage. For the OS, I have a solid state drive (best I could afford 4-5 years ago was an 80GB) that the OS is installed on. It takes a little tweaking to get it to default to installing programs onto the data side, but it works nicely. The result is a 10 second boot time, high speed OS functionality, and excellent data storage. However, I've been eyeing some 1TB SSDs for around $200-400 on newegg for a possible upgrade. I might end up just getting 1-2 of those.

Hah! That would make a pretty decent plot for a scifi book. I suppose they harvest crops by making crop circles since this ends up being less 'conspicuous' as far as someone mysteriously stealing crops is concerned. A guy complaining his crops were stolen in the formation of a crop circle ends up looking like a crackpot rather than a guy with a legit claim of theft.

Fair enough, though it still seems like you could make that happen AND have nice aerodynamics through the use of blow-out panels. As in, its a surrounded skirt, but when its time for the engine to light off, explosive bolts detach the panels.

I've never been able to understand the Russian fascination with those weird strut skirts on their rockets. It seems like that just degrades the aerodynamic characteristics of the rocket.

You fool! That is how you build a kraken beacon!

In my classes they did, but it was basically used interchangeably with "degrees of freedom". Most people in those classes tended to use degrees of freedom because it sounds less ridiculous.

Well yes...thus my statement to that effect at the beginning.

Strictly speaking, if we had one that was positioned correctly and everything went perfectly. Just the one. More likely, the more the merrier! From what I am told it is actually a point of pride amongst hobby radio operators to participate in such a thing and so there are ways of recruiting help in their various forums.

Amusingly enough, within mechanical engineering in linkage design, you routinely deal with adding and subtracting infinities, which is a completely different situation that won't help OP here. Example: You have a fixed bar. It can not move or rotate. Everything about it is known. Zero infinities. You now have a second bar that is attached to the first bar with a hinge. The first bar cannot move, but the second bar can rotate at the point where the corners meet. Because the second bar can rotate to any angle between its limits (0-360, 0-45, 0-90, 0-45.12341235, doesn't matter) you have a system with 1 infinity in it. You now add a third bar to the system. One of its ends is hinged to the end of bar two. The other end is left free. The same conditions to bar 2 apply to bar 3. Bar 2 can rotate wherever it wants and is not mechanically forced by 3 to be at any given angle. 1 infinity. But bar 3 is also not being restricted by bar 2, it can be at any angle on its hinge. 1 infinity. 1 infinity + 1 infinity = 2 infinities. You now take the free end of your third bar and you give its free end a hinge that connects to the free end of the first bar. Bar 2 cannot rotate because one end is stuck to an immovable object, the other end is can only move in a way that would stretch of crush bar 3, which it cannot do. 0 infinities. Bar 3 also exists with these conditions and thus cannot rotate. 0 infinities. 0 + 0 = 0 infinities. There is a lot of math and formulas that go into trading infinites to make your system more predictable with less motors and actually being able to get the motion you want.

I'll concede on the point of Boeing buying rather than building the engines, though that does technically just transfer my argument over to the companies that build the engines. As far as 3D printed metal, I have to disagree with your statements primarily because of several reasons. First off, just about all those issues are things that can be taken into account for what you are making either with current tech or near future tech, there is a LOT of money going in towards solving all of this. Second, if the resulting metal really was crap, then you wouldn't have NASA switching most of their rocket nozzle production over to 3D printed nozzles or SpaceX constructing the vast majority of their SuperDraco engines in single-print 3D printing processes. I'll concede that as a result of the geometry of possible printed parts there may be some issues with surface treatments (internal cavities, etc), but that the idea that all metal printed parts have this issue is just wrong. You can always do post printing processes on them to provide them with appropriate finishes. Sand them down, buff them, etc. The idea that the resolution of a printer will always be worse than the device that made it is quite false. Yes, a lathe will produce a more round object than something printed off a stepper style printer, and even quite likely one produced by newer servo style control. But not all printing technologies are created equal, just as not all manufacturing methods are. Different applications will provide different results. A lathe is likely to be more precise than a drill press, but lasers are getting more and more precise with their applications of energy. In plenty of instances lasers are the go-to if you have the cash. Laser sintering/curing printing WILL overtake bulk production methods in precision and I would need to do some research, but I would bet you they already have in some applications. Here is why. With something like a lathe, regardless of how precise your positioning and control systems are, the process IS still a purely mechanical process. This introduces certain unpredictable forces and vibrations that WILL limit precision of the device. Those same grains in the metal that you bring up, slicing into a new one is altogether not too different from a forces perspective on the scale of a full lathe. But when you get down to small enough scales it is causing movement within the cutting edge. Ever so slight movement. Can we dampen this out? If we have a way to predict it, maybe. But the issue comes from the fact that unless your cutting surface is super small, then you are going to be unable to fully dampen out the forces coming from two different grains entering the cutting surface at the same time. Mechanical cutting techniques by the very nature of how they actually work are completely unpredictable on a small enough scale, which seems a little counterintuitive, but has some good reasons. [Apologies, this part may seem a little patronizing, but the background is important.] The question of if something can cut something else comes down to a few questions. How hard is each material? How much force is being applied from object A to object B? And what area is that force spread across? Depending on how deep you want to get, there are more variables, but these are the heart of the matter. How much force is very important simply because without enough of it, neither material is going to deform the other. What area is the force spread across is important because the actually important variable is force per square unit of size. IE: Pounds per square inch (PSI), or for the metrically inclined, grams per square millimeter. Fun fact, a 100 lbs woman in stiletto heels exerts more pressure on the ground at the point of contact than a 20+ ton Abrams tank does. This is because her weight (and thus the force of her standing there) is focused onto a tiny point, whereas tank treads spread the load around. Now that we know the force per square unit size, we look into the hardness of the objects. Whichever object is experiencing a PSI greater than its hardness allows it to resist, it will deform. Both objects may deform at the same time. So, if you made a blade that is as sharp as possible (one molecule wide blade), you have maximized the pressure you can exert with a given force because the size is as small as it can get. But remember, equal and opposites apply. The force acting on your cutting blade is the same that is being applied to the object to cut. Chances are good that you are not using some magical material with infinite hardness. As a result, you will experience a deformation of both the cutter (object A) and the object to cut (object . The blade will continue to deform (flatten) until it has reached an exposed surface area such that the PSI between objects A and B is no longer sufficient to deform object A. Below a certain scale the realities of molecules and how materials hold together and/or separate come into play against you. The surface of the cutter will not be flat perfectly, because this would mean that material pressing past the edges of the flat plane would again be exposed to near zero surface area and thus near infinite forces. Note, this 'rounding' is still on a super-fine scale so the blade is still quite sharp on the macro scale of your finger! So the result is that the cutter WILL assume a mostly rounded shape with an extremely small area of near perfect flatness. To tie this back into rockets (this being the KSP forums and all) we know that a flat object undergoing reentry will accumulate a layer of gas in front of it that simply cannot get out of the way in time for the next bit of matter. This is exactly the same as for cutting surfaces that have become rounded! As your blade cuts something fascinating occurs. I sadly was unable to find the videos that MIT made decades ago showing what I am about to describe, but I will do my best to paint a picture for you. As you build up this layer of material as your cutting blade 'undergoes re-entry through the other material' (sorry, couldn't resist that analogy) a curious thing happens with the buildup of material. The further away you get from the cutting tip, the thinner this buildup gets. Meaning that after a certain distance, the buildup has again formed itself into an atomically perfect blade! Right now you might be thinking that this is me proving Idobox's point since the cutting tool is cutting with atomically perfect blades. Except remember when I brought up those very same grains that Idobox used against me? They are very important here! Those same grains result in uneven forces being applied to this atomically perfect bow wave that the cutting blade has. This results in the bow wave collapsing almost in its entirety. So where does it go? Either into the surface of the part you are cutting (and thus ruining its perfect cut), into the ribbon or chips of metal coming off to the side, or more likely, both at the same time! It is entirely unpredictable! This establishes that in general, for a given hardness of your cutting tool, and a given hardness of your material to be cut, there is a minimum resolution beyond which you CANNOT reliably cut. This is the limit imposed on cutting tools. Unless we come up with some near infinitely hard material or nigh-2D energy blade, this is where the ability of mechanical machining processes to get more precise comes to an end. Period. Now, this minimum cutting precision that I have mentioned is STILL on an absurdly fine scale. You will likely be unable to tell with your fingers that this is anything but smooth. But we have devices that can very easily detect just how unpredictably jagged even the smoothest of machined surfaces actually is. Fun fact. Don't try using these machines on your fingers. They are sharp. Very sharp. Now, how is it that 3D printing can overcome this limitation on physical processes? This is because 3D printing is not actually limited to the physical realm for all of its processes! Why is that? For technologies used in extrusion printers, they are entirely mechanical in nature. For printers utilizing laser sintering or curing, all of the hard work of precision is achieved almost entirely by electronic processes! For a great deal of laser technologies, they are steered via a galvo. A galvo is basically a mirror on an electric motor. Because of the aforementioned physical process limitations, the galvo can really only steer a beam of energy as precisely as the motor can turn. But this is not the only way to steer a beam. There exist technologies that allow for purely electronic steering of beams. Generally speaking, phased array systems are an example of such. There are no moving physical parts involved. Suddenly your precision becomes purely a matter of how perfect your crystals are (we are getting better and better at making them, and due to the very nature of how crystals work, it is possible to make a perfect crystal and KEEP it atomically pure) and how precisely you can control your electronics (IE, how fast your clocks are and how much noise you can dampen out of your power systems). So, what this means is that we can steer a beam with nigh-atomic precision in controlled circumstances (which a production area designed for this method would be). The new mechanical limit of the system is on your ability to lay down a thin layer of material, and to do so evenly. This is an area that any company researching non-extrusion printing technologies is investing most of their R&D budget into. Laying a single atom/molecule layer down perfectly evenly isn't easy to do, but it is at least possible to do within the tolerances of a couple atoms/molecules, unlike mechanical cutting on the level of atoms which simply cannot be done reliably. TLDR: Mechanical processes have a limit that is basically impossible to overcome short of a nigh-infinitely hard material to use as a cutter. Printing processes can be almost entirely electronic in nature (except for the material being printed) and thus can achieve a precision far more precise than mechanical can. (Edit: I always find it funny when I type up something like this in the 'Quick Post' window.)

Luis tells me he envisions the system working entirely in the IR realm, but as far as I am concerned, if the only way we can package it together involves visible light, I doubt it will do too much to the moss to have light for a couple fractions of a second.

The nozzle width is fixed at what it is. But that doesn't mean it is not precise. If they can position the edge to a micron (0.1 mm, or high resolution for current printers), then as long as you don't require a feature that is less than the width of a single nozzle path, you are fine. Now in the video of the prototype, they were caring more about proving that the overall concept design rather than on improvements that make the final one better. I hate to be the stereotypical example of what you hate...but we WILL be able to do that. We can already do that. I can 3D print an entire clock right now if I wanted to as one piece requiring no assembly from me. If I went really fancy it could even have the chain in place, then I either print off a heavy weight, or I just shove a tiny block of metal into the weight bucket. Bam! Clock. If I want, I could design it so that all I have to do is slot in a DC motor with a battery pack and everything else is finished. Frankly right now if Boeing wanted to, they could likely print off the engines to a 747 or whatever as single print jobs, then slap on the assorted electronics and whatnot. They don't WANT to do that mostly because they don't get anything out of it. Right now to switch their tooling over would be exceedingly costly because of how heavily invested they are in their current mode of production. Additionally, at this time they do not particularly gain anything out of doing so. But eventually once a printer exists that lets them produce the engine with all the electronics and whatnot on board the calculus will change. If suddenly it takes a month to build one engine, but they work on 4 in the space they normally would work on 8 AND they don't have to pay hardly anyone for the process. Even if their usual build time is two weeks, they will have a hard time justifying NOT doing this. After all, for an initial massive expenditure, they will be able to match their production rate and then over the course of several years enjoy the fact that they went from many hundreds of workers down to like 20-50 people. Now of course, the big question is, is there anything that bulk manufacturing can still do to keep the balance tipped in its favor. The answer is certainly. But you will see some markets end up dominated by 3D printed production. Particularly in the realm of specialty device markets. Companies HATE to do 1 time engineering if they don't have to because it costs so much for so little gain. But with full on printing factories it suddenly becomes cheap to produce the prototypes or one-off runs of a device. Plus if suddenly the device manages to form a market around itself unexpectedly, they can just keep running off prints of it without having to devote the funds towards tooling up an assembly line. Look at all the Kickstarters that spend months and months sitting in limbo because they are working with the manufacturers on setting up production lines. Admittedly some of this can be solved by better planning on their part. But suddenly now they don't need to bother. Right now we are sort of in a 'phase 1' of 3D printing, where we are getting better at any given material by itself (right now we can basically print metal by itself, or plastic, but not together). 'phase 2' is where we are working on printing multiple materials at the same time (metal on plastic, so basically doing circuit boards). 'phase 3' is either where we primarily work on increased speed and/or precision (printing the processors into the boards as the boards are printed).

Exactly! The intended result of the machine I was discussing was that you'd have a line of rails running parellel with the road you are building on. Once the printer has finished with one house it moves to the next. The only thing you need humans for is to keep it supplied with material, to make sure it isn't having any issues (it's a machine, machines have issues from time to time, same as people), and to do the detailing work after its done.

The printer itself? Frankly not a whole lot. Most of its existence is just the metal truss structure, very cheap. Sure you have the gantry motors, industry grade with precision position systems, expensive but not obsurdly so. The horizontal traverse, again industrial grade with precision positioning systems. The Z-height can be done through many ways, none terribly expensive. The extruder will be a little different if only because its a somewhat non-standard system. But in general there isn't anything super expensive in there either. I build 3D printers as a hobby and have been looking into the possibility of building one of these mega printers for a while. They are costly for a single person, but for a business they really are nothing special. Think of a mobile truck mounted crane, that is roughly how expensive one of these costs. Insulation? Not at all. Your walls are a foot thick cement box filled with sand. Perfect insulation, super cheap, AND it helps protect your home from things like tornadoes and the like. For the flooring, sure you need to add some tilework, woodwork, etc. This is a trivial aspect of home construction, literally a part that the owner can do themselves if they want. Excepting for very fancy or specialized work, this has VERY little bearing on the final cost of a home in terms of the construction cost. Roofing? I somewhat presume you are speaking of the outdoor roof as any indoor ceiling is basically covered by the same description of flooring. This part gets into quite an interesting debate honestly. Considering that your standard slant-roof is somewhat unnecessary given these construction methods, the effort is minimized. Still want a slant roof? More costly because more material, but at the end of the day you can save money because the roofing will not need to be replaced as often. Effectively ever really. Plumbing and electrical in some ways is easier, in most other respects is unchanged. The walls would be designed for ease of adding in the pipes and wires. About the only real drawback to this system is that it ends up being inflexible. IE: You cannot easily add a new power box to a wall unless you designed all the walls to have the requisite pipe/wire channels. Which there is no additional cost to do. The vast majority of the cost in building a home is NOT materials, it is the fact that you need to pay dozens of laborers for 6 months to construct it. There is a company that every year constructs a house in under like 3 hours as a promo-gimic. The cost comes out roughly the same because they hire 20 times as many workers, but they only hire them for half a day. Their models state that it really only ends up being the same because they don't do it all the time. If they did, then the workers would adjust their costs upwards. Kerbiloid: My comment about the morlocks is not people growing 'cave adapted' as Dwarf Fortress would call it. I was referencing the movie "Time Machine". SPOILERS: He jumps to like 2050 and they have this grand plan of using non-radioactive nukes to blow a large chamber beneath the surface of the moon, which will then become the space they build a colony in. Jump forward a year or two....oops...shattered the moon. Now everybody has to live in underground shelters, etc.

That was the point of discussing my old laptop. With the exception of non-performance impacting parts like the screen or keyboard, the laptop is basically factory fresh in terms of hardware and software. Bought a brand new HDD for it to load the OS and driver packs, etc on. Generally speaking yes, if the user has not set up some sort of recurring scan (I set mine to do a full top to bottom scan of every file once a week) then malware will certainly do that. I assume that to one degree or another the user in question will at least occasionally pull a check of some sort as this effort is minimal (literally just a few button presses). Considering the fresh hardware and pristine OS, what else might you say would be the cause of 'out of the box' slowness in the modern day, given the systems past capabilities, if not software bloat?

The airlock probably would be arranged for a minimum of stair climbing in a suit. Those pits would certainly be nice to use. Of course, lets all take a moment to remember that we shouldn't use non-radioactive nuclear weapons to create spaces under the moons surface to build a habitat on. Unless you want Morlocks. Because that's how you get Morlocks.

Actually this is far incorrect. There have been experiments done in 3D printing houses using a combination of concrete for walls/floors and metal supports for overhangs. The projections from the half scale prototypes state that you could have a two story house meant for a family of four printed out in roughly 20 hours and a full neighborhood inside of a week if you have a good alignment between your gantry rails and the road in question. The best thing about the system is that generally speaking houses of wildly different designs, but of the same volume, take almost about the same time to print. No specialized materials are needed for any given home printed by the system. The concrete used is one of the super fast curing (sp?) types which contrary to popular opinion really isn't all that much more expensive then standard foundation concrete. You go to the same plant, you just request a different mix. They WILL have the necessary ingredients because it is mostly a question of ratios rather than adding or subtracting something special. The professor developing the system has been going about it slowly (he has a day job as a professor after all) over the last 5 or so years. The main impediment he sees to the adoption of the system is simply the fact that we don't build enough homes in the US to really justify needing this system. Honestly though, I think he is mainly just working on the version that can build skyscrapers.

This is sort of what I mean though. Yes, I acknowledge that THAT is the most efficient way to go about the whole thing. However people rarely actually go through with this in my experience. Again, power users who stick to their guns will do so. But the average person will just ride the computer down in flames because the act of spending money "now" (after the computer was bought) to make it better requires a new activity. Chances are by the time the computer reaches truly unusable levels and they decide to kick in for an upgrade, they aren't going to be imagining just a new graphics card, or a little more RAM. They'll be thinking about a new machine entirely. After all the attitude of "Look how bad it is now! Clearly one or two new components are not going to fix it!" is real. More then that, it ends up being to most people a 'devil you know' problem. They don't know for sure that changing out the RAM is going to actually solve their problems. And it is very easy to imagine buying new RAM, putting it in, and the computer being basically no different. In which case they would feel they have wasted money. Actually going out and buying parts piecemeal (which is what they WILL do. They will default to buying one part at a time, because if they are bulk buying...why not just buy a whole new one?) ends with negative confirmation bias. Unless the part in question has a rather major effect on the machine in question and basically solves ALL their problems, they will feel that their earlier theory that they were wasting their money was the right gut feeling to go with. Buying a better processor and making everything run faster doesn't make them feel like they have won if everything still runs slow or crashes because of insufficient RAM. Meanwhile they can know with absolute certainty that if they buy a whole new computer from scratch, when it shows up they WILL be satisfied with the speeds and responsiveness. They will feel positive confirmation bias, because after all, look how much faster it is running! Plus you get a sort of inverse sunken effort fallicy going on with it too. After all, the three main aspects of the computer they are going to be upgrading are the processor, RAM, and graphics card. (I leave hard drives out, because space issues are a different beast.) And when you get right down to it, what more IS there in a computer that you honestly care about? The power supply, the case, the motherboard, the hard drives, and whatever internal peripherals you like (CD tray, etc). Most of those you can reuse...plus those are honestly the cheap components anyway. So even if they intend to just buy the main three, they will look at the others and go "hmm...with an extra $500 I can just buy all those, then everything is brand new AND I have a second computer...That is only a 25% increase in price anyway...Yeah! Let's do that! OOOH! Since I'm getting a new computer, I'm going to need a new monitor!" etc. I see it time and time again. After all, they have decided to sink 2000 on new hardware...and another 500 on new extras....why not toss in another 500 for a new this...and 300 on a new that.... What I am arguing here is NOT that your method Camacha is the wrong method of computer buying. I fully endorse it as the best method! What I AM doing is arguing that, because of pyschological reasons, unless the average user in question has a reason why they MUST abide by it (I literally only have 500 to spend, I cannot afford a full 3K gaming beast even if I decided not to eat for a month) they will get more out of the wastefully extravegant computer in the long run. This is because if they have the ability to buy a whole new computer when their current rig starts slowing down, they WILL do so. And since they will do this, then the optimum cost strategy is instead to buy a computer that will last them as long as possible before they have to replace it. I don't have any hard numbers to provide, but comparing my experience to that of a friend of mine that economically HAS to upgrade piecemeal, my costs over time end up only being slightly more than his. However, this is dependent on his aging components NOT failing in a way that takes out other components. Unfortunately this happened to him about a month ago, his best guess is that a cap of some sort on the motherboard popped, caused a short that dumped supply power from the PSU into the processor and graphics card. Those are both DOA, the motherboard cap clearly trashed. But the RAM is useful and the PSU tests good at his lab. That said, I am staring at him as he goes through exactly the same logic I have described above. Again Camacha, you are right from the perspective of a computer person. I am arguing from the perspective of the psychology of the situation rather than the technical side.

The problem with this idea though, is that it doesn't actually help YOU the guy who did this damage. If the station was properly designed, compartmentalized, armored in current battleship methodologies (all or nothing style), etc, the only real way to actually make it combat ineffective and thus no longer a threat to you WOULD be to basically shatter it. The reason why is this. Right now if North Korea were to launch a single missile at a US carrier, and lets say it managed to hit but not sink the carrier. Let's even say nobody died or was even wounded despite the damage to the ship. The damage while visibly impressive in this particular example is also not enough to keep flight operations from occuring. While standard carrier doctrine WOULD be to head home for repairs, lets say the hit just happened to be the engines so this carrier is going nowhere. A battle station can't go somewhere for repairs, it is always going to be 'next to the target' because it is basically fixed in its orbital path, so this is roughly comparable. It is a safe bet that the resulting war would most certainly involve combat operations from this damaged carrier. So if you think just dealing a bunch of costly, but ultimately superficial, damage to this orbital battlestation is going to keep it from being used against you now that you have opened up war-grade hostilities? Now one thing to point out that actually changes things a bit here. Peaceful naval doctrine is basically always dictated by the immediet threat. If we had a battleship roaming around the ocean and a North Korean ship attacked it, the battleship captain is fully within his orders to destroy the threat to his command. IE: Sinking the NK ship. But what is NOT within his orders is to then immedietly set sail for NK's shoreline and begin bombardment of military locations until ordered to do so by a higher authority. Can he open fire on sight of a new NK ship an hour later? It wouldn't be held against him, but he WOULD be held accountable for at least warning it off via radio. After all, things could have been a mistake, the captain could have acted alone against the US, etc. The point being, the immediet threat has passed and he is expected to prevent an escalation with the understanding though that he will do what he must to protect his ship. I can almost guarentee that the spirit of what I have described would apply to our orbital battle platforms. NK tries launching a satellite killer of some sort at it, the commander of the platform is well within his rights to take action against the incoming threat as well as the launch facilities in question which involves a direct bombardment against an enemy nation in no uncertain terms. Captains in this situation will be granted quite a bit of latitude in how they respond. Once they have committed to the bombardment if the Captain stops there, he risks his command the next time the station flies overhead if NK had other launch facilities. If he decides that the correct response is to expand his bombardment to involve every possible threat to his command in NK, the admiralty will almost certainly back him up. After all, NK wouldn't have gone against such a high profile target without expecting the feces to hit the fan if things went south. Don't think they wouldn't be given this authority. Remember, in the Cold War, boomer captains were basically expected to light off against the Soviet Union if their judgement decided it was time. Yes they were SUPPOSED to try and contact home first, but in the absesce of that information...best judgement.