-Velocity-

There is an increasing trend within science education to do away with using Bernoulli's principle in explaining how wings work. The Bernoulli's principle explanation is over-complicated and usually explained incorrectly. It is also not intuitive. Most people are coming to realize that it's much more simple to teach that wings produce lift by pushing air down. So it is the angle of attack that creates the lift. A non-symmetrical wing, if angled so that its geometric average direction is parallel to the air flow (instead of the bottom surface) will also produce zero or almost no lift (maybe even negative lift). Basically, wings push air down, and so they get pushed up. Very, very simple, and it's a correct explanation of the forces at work. Whoever is responsible for mixing Bernoulli's principle into the explanation should be shot, as they left at least two generations of people not understanding how wings actually work. That included me, until I played enough flight sims (where the relationship between angle of attack and lift was made clear to me), and looked up enough resources, to realize that the Bernoulli explanation was bull!@#$. To demonstrate how wings work, just stick your hand outside your window while driving your car fast. First, angle your hand so that it is directly into the wind. You'll feel no lift. Next, angle your hand upward, so that your hand pushes down some of the air streaming past. You'll feel your hand (rather strongly) being pushed up. Really, that's it. Lift is that simple. It's a travesty that they over-complicated it to the point that they did. Oh and by the way, the reason that wings are curved and not flat isn't because of Bernoulli either. It's so that there are less vortices generated- less drag.

1) The amount of engines you can stack underneath the rocket increases by the dimension of the rocket squared; 2) The amount of thrust needed is proportional to volume and thus increases by the dimension CUBED. Therefore, your rockets become fatter and fatter the heavier they are, so that you can pack enough engines on the limited surface area of their back ends. Now in KSP, fat isn't always a problem, because of the unrealistic way that drag is calculated. However, fat becomes a major problem when you want asparagus staging. This is because to get fat enough, you have to use multiple fuel tanks placed radially on each other. For a 4000+ ton rocket, it's a huge number of tanks you need to use. On each stalk, you need all the fuel tanks to drain out BEFORE the next stalk starts using fuel. And with the HORRIBLE way that fuel flow works in KSP- there's no way to tell KSP to treat two fuel tanks as one (no, running fuel lines between them does not do it)- that's VERY difficult to achieve when you start stacking together a lot of tanks. What you get instead is that the next stalk will start draining fuel before the previous one is finished Oh it's not impossible at all. One solution I can think of is to use a LOT of stalks. You might have like 10 stages or something. But for big asparagus rockets, I've always tried to use six-sided symmetry and have just four "stages" (7 stalks - 5 stalks - 3 stalks - 1 stalk). It simplifies things. So anyway, for my 5500 ton lifter (4700 ton rocket + 800 tons LKO) I just ended up using liquid boosters and vertical staging. Not as good as asparagus, but simple enough that it doesn't take an eternity to perfect. I think each launch with that thing is like 2.5 million kerbal dollars though, lol. What is onion staging?

A really good rocket, non-airbreathing (stock) can get in excess of 1/6 payload fraction. I think that 1/5 is doable, but it can be hard to hit. On my 5500 metric ton launcher (includes 800 ton payload), my payload fraction is substantially reduced- about 0.15- less than 1/6. In this case, the problem is that when you get to really, really big rockets, it's VERY hard to get the fuel to flow to flow correctly- if you're trying to use asparagus staging, that is. The largest rocket I could get asparagus staging to work correctly for was my 2200 launcher (includes 400 ton payload)- that's a payload fraction of about 1/5.5. As I'm now playing the 0.24 career, I started playing around with air-breathing SSTOs for refueling an orbital fuel depot- the idea is to save myself having to launch single-use fuel tankers. I actually ended up having more luck in the VAB than the SPH. I basically make a rocket (with huge fins, parachutes and landing legs) that launches as an air-breather, climbs to around 11km, slowly makes a turn to level off at around 17 km, and slowly climbs and accelerates till at about 24 km and going around 1300-1400 m/s, it kicks into regular rocket mode to take it the rest of the way to low orbit. I believe my payload fraction of excess fuel I can get into orbit ends up being around 1/4, if I remember correctly. It might be able to do better with more tweaks. Unfortunately, the number of SABRE engines you have to use starts to become excessive if the rocket gets much more than like 200 tons in mass.

Regardless, compared to piece-by-piece molecular assembly of a DNA molecule, finding a cell to receive your assembled DNA is easy.

So what? You're fixating on a problem I am pretty sure we have ALREADY solved. You can take a frozen embryo- it probably doesn't even have to be from the exact same species as the one you intend to grow- thaw it out, remove the original DNA, and insert the DNA of the species you want to grow. Don't we already do this today? Regardless, compared to piece-by-piece molecular assembly of a DNA molecule, finding a cell to receive your assembled DNA is easy.

Generation ships are silly and inefficient and will probably never be built. It's simply vastly more efficient to store organisms in data banks of some sort, and just grow them when you reach your destination. We have vast strides to make in biological technologies that will probably be completed well before we're ever ready to launch some gigantic spaceship on a 1000 year journey. When we have made those advancements, we'll be able to grow humans in vats or whatever the equivalent is. You need at least 20,000 people for a colony? So what, that's just: Human genome: ~3.2 billion base pairs Four different base pairs -> each base pair represented by two bits Eight bits in a byte-> each byte can hold four base pairs; Storage capacity required for complete human genome = 3.2 billion / 4 = 800 MB Storage capacity required for your entire colony's genome = 800 MB * 20,000 = 16 TB. So you can store your entire colony's genome in a small, manageable amount of memory. (Obviously, you'd want to back that up with probably (at least!) triple redundancy for your 1000+ year voyage.) The biggest challenge right now is assembling an arbitrary DNA molecule. We can't do that- not yet. But with the way biotech is advancing, and the huge amount of room it has to advance further, it seems fairly reasonable to suppose that a solution will be found eventually. It certainly seems more likely than some gigantic, battlestar galactica colony ship that costs 100 million billion billion dollars. Even if colony ships somehow become practical, if a vastly cheaper alternative is available that has the same effect, no one will build them anyway.

If it's a Mars-sized world, it's not likely to have enough volcanic activity to have a magnetic field unless the system is young. Mars is mostly-dead geologically, at least compared to its initial conditions. It's small and it cooled off long ago. Maybe there are still occasional burps of volcanic activity (which was a real surprise, in fact, when that was discovered), but there is not much. It hasn't been able to sustain a geomagnetic dynamo for billions of years. 0.1 ATM is more than enough atmosphere to support significant weather. Present day Mars has dust storms, cirrus clouds at all latitudes, thicker clouds (stratus?, I donno, but you can look up animated gifs of them) seasonally present around the poles, and even water ice and dry ice precipitation around the poles (the Phoenix lander detected BOTH occurring simultaneously, in fact). Mars is only 0.006 ATM. Look up a phase diagram of water to figure out under what temperature ranges fresh liquid water would be stable. It won't be that large. I only suggested aliens because it provides an interesting back story. A good writer will provide an interesting, detailed, and mysterious universe to keep a reader engaged. Sure, that can be done without resorting to aliens, but don't limit the scope of your vision too much. Anyway, the ideas about a cool Venus was also at a time before we really understood how atmospheres worked. We also didn't realize how ridiculously thick the Venusian atmosphere was. I doubt there is any way to have a dense atmosphere with reflective clouds where global warming would not run amok. You're better off thinning out the atmosphere some. Also, volcanoes spew massive amounts of greenhouse gases into the atmosphere. After they are done spewing out sunlight-blocking ash, the planet heats up. If you had massive volcanic eruptions happening enough to keep ash suspended in the air, I suspect that the atmosphere would be choked with greenhouse gases, probably enough to overwhelm any cooling by the transient presence of ash. You're better off just making the planet have a thinner atmosphere with less greenhouse gasses. Either that, or imagine a Venus analog moved far out enough where the surface temperatures start to become bearable. Basically, you might want to move your planet #3 OUTSIDE the orbit of planet #5. Present-day Mars is in the habitable zone, after all; if early Earth were placed where Mars is, it would be quite habitable (though the atmosphere would not be suitable for us). Mars is simply too small to hold a large enough atmosphere for significant global warming. Some recent research cast doubt on the habitability of exomoons, I can't remember the reason though. However, I'm sure you could find some contradicting research in favor of habitable exomoons somewhere too. Exomoon habitability is a tough problem to solve. Consider that in determining habitiablity for exomoons you have to take into consideration tidal heating, the magnetic field of the host planet, sunlight reflecting off the host planet, the radiation belts of the host planet, etc. IN ADDITION to all the other factors that you have to consider with any planetary body. We'll likely be even further off the mark with predicting their habitibility than we are with predicting "regular" worlds. It's best to stay away from exomoons, IMO.

Planet 5- probably a CO2 atmosphere. If the atmosphere is thin and underwent a lot of erosion, then CO2 is more likely to remain than nitrogen, since it is heavier. How massive is your planet 3? I'm not sure that I can think of any plausible way to get a thick atmosphere that does not cause significant warming. Venus is a highly reflective planet- if I remember correctly, its albedo is around 60%- but even with all that reflection, intense global warming far outstrips reflection. How about this- your planet #3 is only kept habitable by a mysterious fleet of ancient, self-maintaining robotic solar shades that hover at the Lagrangian point between the planet and the host star, blocking a large percentage of the star's light. These robotic solar shades were set up by some long-gone, ancient alien civilization. (This is also a plausible way to maintain the habitability of Earth into the distant future, and is far more practical than the only competing idea I know of- expanding Earth's orbit with millions of asteroid flybys.)

Hawking is hardly the first person to point this possibility out. Physicists have long known that it's possible that our current vacuum state could be metastable (a long-lived "false vacuum"). The scary thing is that the Higgs mass appears to be in the proper range, or close to it, to indicate we are living in a false vacuum. The good news is that predicting doomsday may be a little premature, as the laws of physics beyond the Standard Model that we are still ignorant of will likely play a big role in determining the ultimate stability of the universe.

Of course we go with that attitude because NO CHANGE is exactly what most or at least many people want. We don't want to have to learn how to do everything all over again. Improvements to functionality, new features, better efficiency- that's what we want with new versions of software, not a completely redesigned UI that keeps me scratching my head, just figuring out how to do the most basic of tasks. As an example, I PASSIONATELY hate all the changes they keep making to Microsoft office. It's not that the new interface is bad, it's just that the change is bad. We learn a certain system, become proficient at it, and then BAM Microsoft changes everything and it's back to square one. I am JUST NOW getting used to everything in Office 2007- and I've maybe made 1000 PPT slides and 300 to 500 pages of text in it- who knows, maybe more, as it use it every day just about. I've been using it since it came out, and I am FINALLY just NOW getting used to it. I am no idiot either- oh I could figure out how to do stuff from day 1 (well, after people showed me where the File menu went to...). It's just that I want- no, need- to become so proficient at operating a piece of software that it's second nature and I don't have to think about it at all. I don't want to have to break my concentration on what I'm thinking about to figure out how to turn off snap to grid or remove the space MS office keeps inserting after every damn paragraph. Information has to flow seamlessly from my head to the word processor or slide with no hick-ups or annoying distractions.

Well, as long as we're talking sci-fi, why not just scan in their brains/minds/whatever and transmit the information to the ship. The ship can grow or build new bodies for the transferred minds and upload their consciousness to the new bodies when they are finished. Unfortunately, that still leaves the original instance of the person's consciousness stuck on the planet, but assuming that the information is copied perfectly, then there is no functional difference between the original and the copied minds. That of course assumes that all information that makes up our consciousness and memories can be copied. The only thing that can't be copied in the universe is quantum information. However, quantum information can still be transferred to a remote location via quantum teleportation. So if the mind makes use of quantum effects to create consciousness (and current research suggests it does not) then minds could only be transferred (via quantum teleportation), not copied.

There's not enough evidence of a large impact just 10000 years ago. There is no crater, no asteroidal dust layer. We have ice cores going back like 200,000 years, and any such impact would leave an obvious, unmistakable layer in them. Heck, we probably would have known about this impact before we discovered the Chixculub impact that killed off the non-avian dinos. All the other purported impact layers supposedly associated with a YD impact have been shown to be not from an asteroidal or cometary origin, or at the very least, have been shown to be unlikely to have been caused by an impact. You honestly think that a 50 km+ wide asteroid could have hit Earth only 12000 years ago? That's laughable. Such an asteroid would pack at least hundreds of times more energy than the one that killed off the dinosaurs and likely leave an impact crater five hundred miles across, if not bigger. There would probably still be volcanic activity in the crater today, and almost all life on Earth would be destroyed by such an impact. Certainly humans could not have survived such a thing. It would probably be the biggest, or one of the biggest, impacts Earth had sustained since at least the Late Heavy Bombardment like 4 billion years ago. It would certainly be the largest known impact with Earth, other than the one that caused the formation of the Moon. Anyway, you need to re-examine your position because it lacks scientific or logical basis.

This is "just" transmitting a message from one brain to another using a means of physical communication- in this case, electronically. The only thing truly novel is that the message was sent and received directly from the brain, rather than through voice, text messaging or some other communications system. It's just one small step on the way to our (likely) transhuman future.

Wrong, you are using Newtonian equations (0.5*m*v^2) on something that REQUIRES relativistic equations. For the relativistic equations, see this- http://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies In reality, the impact of the ISM into the front of a ship moving at relativistic speeds is a BIG problem. For protons and H2, it represents a source of radiation, but the REAL danger is interstellar dust. There is quite a bit of dust out there- The dark areas are all dust clouds (gas is there too), though varying concentrations of dust exists throughout the galactic disk, everywhere you go. A tiny dust grain can cause a huge amount of damage. In science fiction- the science fiction written by authors who know what they are talking about and want to maintain realism- interstellar spacecraft that travel a large fraction of the speed of light usually utilize a large shield to absorb impacts from dust. DOH, how blind and dense can I get? I just noticed that you did switch to the relativistic equations later. I just assumed based off your earlier sentences that you used Newtonian all the way through- I would have never even started with Newtonian myself, so I just assumed you must not have known about the relativistic equations. Oh well, the problem with dust remains.

No asteroids hit Earth at 3 km/s. Velocities range for 10 km/s to 20 km/s usually. The calculator may not actually be able to accurate predict some of the effects if they scale non-linearly and the calculator uses certain assumptions to simplify calculation. Put the velocity at 15 km/s and you'll see something diffferent and much more realistic. Oh and I just noticed your density was way too low. Water is 1000 kg/m^3. A realistic asteroid density is perhaps 2000-8000 kg/m^3 (8000 kg/m^3 being like solid iron), depending on what it's made of and how much empty space it has inside it (if it's a rubble pile, that might be a lot).

The nuclear thermal rockets (NTR) featured in the game are probably too "weak". IRL, we can probably expect Isps of like 1200 s or even considerably more, not just 800 s. 800 s was the Isp of the first ever nuclear thermal rocket. There have been many studied designs that would reach Isps MUCH higher than our first generation of NTR (which were in fact built and tested, but just never flew). So the NTR in KSP is actually probably a little weak compared to what we would make in real life if NASA ever got more than just the last dregs of the federal budget. What is actually sorta cheating (in terms of realism) now is the ion engines, which have ridiculously over-powered thrust to weight ratios compared to their real life counterparts. I'm OK for making ion engines more powerful so that maneuvers don't take so long, but when you make them so ridiculously overpowered that they can be used as lander engines, as they can now, you've got a serious issue (at least, if realistic gameplay is your goal). Not to mention, ion engines work in atmospheres, which is completely unrealistic. Squad needs to make us some electric propellers so that we have some form of realistic electric aircraft propulsion, and then make ion engines only work in a vacuum... and lower their thrust to pre-0.23 levels...

Just a two little suggestions that would improve gameplay a bit IMO- how about a safety for the staging button (default- spacebar)? It would be sorta like a master-arm switch and could be toggled like the SAS/RCS. Beside the SAS/RCS display on the navball, when your rocketed is armed, a red "ARMED" text would appear. There are many times where folks accidentally press space bar (it's right beside other buttons you use all the time), and accidentally stage their vessels. IMO, the staging button should get a safety switch. I suppose users could use a key combination to get the same effect though. Another thing- how about physically representing the staging button inside the cockpit of a spacecraft with the archetypal "big red button"? It could have a transparent safety cover too that gets lifted on and off when the safety is enabled/disabled. When you press spacebar, the button gets depressed. It would add to immersion, and a single "big red button" fits the cartoonish Kerbal ethos, IMO. Perhaps if the safety switch was not implemented, that would be even more fitting of the Kerbal ethos, and the devs could make fun of this fact by having an empty hole in the cockpit labelled "Staging Safety Switch". But it's not usually a good idea to make fun of user's frustrations. However, maybe the staging button should be green, and an abort launch button should be added that is red. That would also work Anyway, on a sort of related note, I would like to see more information added to cockpits (such as the ability to see how much delta-V you have left on a maneuver) so that it becomes more and more practical to control your spacecraft from the cockpit. It adds to the immersion of the game to fly your craft from inside of it.

It's hard to tell where we will go. I recently read an article about how "humans" might be able to escape the death of the Sun and other incredibly distant cosmic catastrophes. I had a good laugh. "Humans"- 6 BILLION YEARS from now? LOL If we still have anscestors alive in that unimaginably distant future, they will NOT be humans. We WILL go extinct. We SHOULD go extinct. Homo habilis, homo erectus, homo antecessor, etc. they are ALL extinct. If homo sapiens never goes extinct, if we never evolve into something else, we're doing something wrong- trying to cling to a past that should be long dead. The future is evolutionary change. And this could come much sooner than natural evolution would normally allow. I think that almost all science fiction stories and futuristic predictions, many of the ones I see on this thread, will prove to be very naive. In particular, any prediction that assumes that the future "us" will be essentially the same as the present-day "us" seems likely to prove incorrect. By 2114, we may no longer be a "human" civilization- we could just be "Earth" civilization (or if space travel and colonization accelerates, simply "Sol" civilization). That is because many of "us" may no longer be "human" or even have human origins. This may not happen as early as 2114, but it certainly COULD. We're progressing on two technologies that could be incredibly transformative- genetics and machine intelligence. Genetics could allow us to take a direct, intelligent hand in our own biological evolution. To date, we've been subject to the nearly-blind hand of Darwin. All we have to go on is natural selection. It's a very slow process, and now that we've essentially taken ourselves out of nature, it may not even be selecting features anymore that make us more fit to survive! An example is intelligence. Studies have shown that stupid people tend to have more kids than intelligent people, so we've probably been evolving slowly towards stupidity over the last few hundred years or so that this correlation has been true. (There is no need to have a lot of kids in the present age; we've already overpopulated this planet in terms of long-term sustainability by at least of factor of two or three in my opinion.) Anyway, when we can take a directed, intelligent hand in our own biological evolution, it's really hard to say how things could change. Intelligent design (by US) can work changes on a timescale vastly shorter than slow natural selection and evolution. Genetics could also lead to the creation of non-human intelligent beings- think of David Brin's Uplift series of novels. The main idea is that it could become possible to genetically modify non-human species into intelligent, technology users that would share the planet with us, make the universe a little less lonely, and add greatly to diversity. That probably can't happen by 2114 though. If we understand genetics well enough, then we could even design our own organisms from scratch. There is much talk about nanotech among futurists- many are basically impossibly-small NEMS systems (I read Neal Stephenson's The Diamond Age and noticed that many of his nanotech ideas were literally physically impossible. I'm an electrical engineer getting a Ph.D. in MEMS fabrication so I have a good ability to judge). I believe in nanotech, but I think that nature already found one of the best, if not the very best, nanotech solution for us- life, DNA, genetics. Every living cell is a wonder of nanotechnology. Why in the hell would we re-invent the wheel, when we can just modify, copy, and engineer living cells? Anyway, the other technology that is potentially radically transformative is machine intelligence. Our fastest supercomputers are only now beginning to approach the estimated processing power of the human brain- if those estimates of the brain's processing power are true (I saw a recent study that claimed we might have under-estimated our brain's processing power by a factor of 10 to 100). It's no wonder at all that we haven't created machine intelligences- our computers are not fast enough. Once we DO have computers that are fast enough, MI becomes a software problem. It's a tough software problem, but with a fast enough computer, we don't need to worry about hardware anymore- we just need to find the right program to run. Assuming we conquer this step, then it really becomes tough to predict the future. MI could become much smarter than even genetically modified humans, and in turn create the next generation of even smarter machines, and so on. This is known as a "technological singularity"- where technology progresses so fast due to machine self-improvement that our ability to predict the future really becomes near to impossible. I think the assumption that machines will somehow be hostile to humans is simply based on our own xenophobia and racism. Since we're programming at least the first generations of machines, we have a big hand in what kind of values they adopt. There will be diversity in thought among the superintelligences, too. If some superintelligent machine does somehow become hostile, then it will be crushed by the vast majority of superintelligences that are benevolent/benign. Biological life also cannot survive in the locations that machine life can, so why would there even be a conflict in the first place? If the machines hated biological beings enough, then they could just go live in the Kuiper belt or some very distant and removed location. Anyway, in the end, I see a future coming where all these sci-fi stories about the human race existing alone in the future- which is the majority of sci-fi stories- will be shown to be naive. We'll not be the human race, we'll not be human civilization. We'll simply be "civilization", or "Earth civilization", or perhaps, "Sol" civilization. And that's a good thing, IMO. If the human race never creates any "children" at all, that will be very sad.

Still no secondary Kuiper belt target for it?

Shame on you, there could be KIDS reading this thread!

http://en.wikipedia.org/wiki/Kilroy_was_here

A lot of the time, you can break the maneuvers up into multiple parts (let's say, I want to go from a 100 km X 100 km orbit to a 2000 km X 100 km orbit- I can do this in a series of steps, burning each time at the optimal point). However, this again runs into the main reason I use enough LV-Ns to get me up to at least 0.5 m/s^2 of acceleration- TIME. Most of us DO NOT have an ETERNITY to sit there waiting for some maneuver to complete. Also, sitting there, watching the remaining delta-V on a maneuver SLOWLY tick its way down, 0.1 m/s at a time, is NOT FUN. It's like watching paint dry or trying to amuse yourself by starting at the second hand of a clock on the wall.

If you have infinite time, your advice makes sense. Otherwise, it does not. I wanted my Eve ship to make it to Eve before I died from old age or went senile, so I used 10 LV-Ns. If I had only used 2 LV-Ns, it would have meant my acceleration was only 0.1 m/s^2 (0.01g!!!). It would have taken hours just to do the transfer burn from Kerbin space to Eve space considering my computer is just barely chugging along at like 1/4X time when running this ship, and that's even considering if I had used time compression... I simply do not have this amount of free time.

Install Mechjeb or some equivalent mod that gives you TWR (thrust to weight ratio) and delta V in the VAB and also during flight. When in the lower atmosphere, you generally want your TWR to be about 2. A starting TWR a bit less than 2 is probably actually better, considering that the more TWR you have, the more engine mass you're having to move. Also consider that a rocket with a starting TWR of like, 1.7 will probably have a TWR of like 2.3 before first stage burnout. So you want to have your first stage to have something more like an average TWR of 2. So don't fixate on getting a TWR of exactly 2. It's OK (probably preferable) to have a starting TWR less than 2!!!! And you certainly DON'T want a TWR well in excess of 2- if you have that, you're wasting a lot of fuel lifting an overly-large engine. If you REALLY want a first stage starting TWR of 2, you can always strap on some small boosters.

Put some empty fuel tanks- aka "pontoons"- on the bottom. They seem to float well enough on Kerbin, at least, last I tested. I used the longest 1.25 meter fuel tank for my pontoon test several months back. Two of those tanks were enough to support the weight of a small VTOL aircraft. It's easier to test now, since we can actually start fuel tanks on empty now You have the limit the speed at which you splash down. If you splash down lightly enough, nothing should break off.