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Everything posted by Hannu2
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why the hell have we not gotten to mars yet
Hannu2 replied to alpha tech's topic in Science & Spaceflight
Colony is by definition an organization which have objective to be self sufficient. Otherwise it is some kind of base. I do not know how colonies will be self sufficient but I do not see any known natural law against it. Of course it does not happen in 2030's like optimists think, but maybe at year 3000. I believe that humankind expands itself to solar system during next couple of thousands of years if there will not be any global megadisaster. There are extremely few examples of rapid political changes towards better world. Such development has always been slow and politicians and other powerful individuals have resisted it in all countries because they have believed that it threatens their power. -
why the hell have we not gotten to mars yet
Hannu2 replied to alpha tech's topic in Science & Spaceflight
It is ideological objective, not economical in any sense. It is extremely low probability that single investor die due to global natural disaster. He can extend his life (length and quality) far better by investing to safety against more common risks. In any case it would take thousand years or more before space colonies would realistically be self sustained and able to grow without support from Earth. It would help those who begin to build it. It is also extremely difficult to imagine such disaster which makes Earth worse than Mars. Asteroid may make winter which lasts couple of years and kill most useful species. But there is eternal winter in Mars with far lower temperatures, lack of breathable air (for humans, animals, plants), lack on any useful species etc. It would be much easier and cheaper to make bunkers against such disasters on Earth. -
why the hell have we not gotten to mars yet
Hannu2 replied to alpha tech's topic in Science & Spaceflight
It is very simple. There are not any economically feasible reason to send humans to Mars. No colony and no expeditions. And there will not be in foreseeable future. There are nothing on Mars which can not be achieved from Earth. Only possible reasons are more or less ideological. Scientific curiosity, political display of technology and economic power (this was main motivation of Apollo), some kind of backup population against natural disasters or humans natural urge to expand. None of them give economic profit to them who pays the bill. Also taking part of such project as an colonist will be extremely painful experience suitable only those who have extreme personality. On the other hand, it is very difficult question why such ideology has not developed. There was some spirit during Apollo-project and cold war, but after that average spending to ideological space projects has been only few dollars per human per year. It is practically nothing. Or what should space enthusiasts do that large mass of people or politicians would get interested in space. I believe that it is just natural fluctuation of human societies. Next generations will want to something more communal and larger than just more stupid electronic scrap and fashion clothes than neighbor. Maybe it creates interest to investigate and colonize space too. We probably will not see it but Mars and other planets will wait. -
why the hell have we not gotten to mars yet
Hannu2 replied to alpha tech's topic in Science & Spaceflight
I agree that colonization of Mars will not be business. As someone wrote, soon after colony would be self-sufficient it would declare itself independent and would not pay anything to governments or companies which established it. Only possibility to get space colonies is that it is made due to ideological reasons. I agree also that colonization equipment manufacturing or transport services could be a good business for companies like SpaceX if governments of richest countries were interested in colonization. Unfortunately, it seems that such interest is negligible. Political interests change so slowly, that it is practically not good business for a rocket company. Therefore SpaceX launches telecommunication satellites and cargo to ISS. Raptors, larger rockets and other Mars technology waits or develops very slowly. There is not interest even to asteroid mining which could be business of thousands of billions of Dollars. -
why the hell have we not gotten to mars yet
Hannu2 replied to alpha tech's topic in Science & Spaceflight
It is difficult to say. Also rich people have fantasies (although most of them want to get just power over others) and it may be that Musk wants seriously to send some kind of colony to Mars including himself. He probably have enough money to by anything which can be bought in this world. However, funding of such project need some huge business. Current launch business is far away from needed hundreds or thousands of billions. Therefore I think that it is not realistic program. Musk also knows it but he tries to create popularity which helps to increase space business. -
This is what I called technomagic and excluded out. We do not know any examples of such civilizations and we do not know any means how that could be done obeying known natural laws. I know that nature have had and will have big surprises and we do not know everything. However, such surprises are typically something nobody can predict. Therefore at least I expect that scifi writers fantasies does not exist before we detect one of them.
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OK, I am back. It seems to be equation 36. It is standard 2D inverse discrete Fourier transform. h_tilde(k) is amplitude and phase of the wave with wave vector k. Wave vectors describe plane waves (straight sine waves). Length of k is 2*pi/wavelength and its direction is direction of wave propagation. In this case you take a square area with side length L and divide it to N * N grid points. You can take values from article. You get N^2 k vectors k_m,n = (2*pi*m/L, 2*pi*n/L), where m and n goes from 0 to N-1. This is set over which summations go. Next you need h_tilde(k). You can use formulas 39-43. They should be quite straightforward to apply. Here you can find how to convert uniformly distributed random numbers to Gaussian distribution. Now your have everything to calculate inverse Fourier transform. Straightforward algorithm would have time complexity of N^4. It is something you do not want to even try if you want to high quality surfaces. Use Fast Fourier Transform algorithm (FFT) (as article suggest) which takes time only N^2*log(N) (difference is about 100000 at N = 1024). FFTs are well investigated area in mathematics and computational science due to its huge importance in signal processing but I am not expert in FFTs. This is one example code and Google can find many more. There are also code libraries (also free) with efficient FFT algorithms. There may be errors in my formulas. It is better to check them with that article. I suggest that you program this basic level before moving to forward in article. Please ask if you need or I overestimated your level.
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- programming
- waves
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Complex numbers are common in frequency related physics. Complex exponential function can be calculated exp(a + b*i) = exp(a) * (cos(b) + i*sin(b)). Wikipedia is useful reference: https://en.wikipedia.org/wiki/Euler's_formula You calculate with complex numbers and when you are ready to draw you take (typically) real part of result as a height value. I noticed that you asked also about vectors. It is scalar product between wave vector k and position vector x. You get some angle like number and use Euler's formula to get a complex number. You calculate sum and then use real part to get height on point x. There is some set of wave vectors. You sum over all of them. I can read the paper and give more advice after about 1 hour.
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Aliens have same natural laws as we have. They have same elements, same chemical (and nuclear) reactions and same thermodynamics. If we do not talk about technomagic I would expect somewhat similar efficiency of their industrial processes. Maybe some advanced civilization can produce significantly more energy, for example by using nuclear reactions or materials from asteroids in their solar systems, but I do not see much possibilities to clearly higher efficiency. If you think that wasting is energy consumption to non necessary entertaining purposes, not much can be said. I believe that aliens have developed in biological evolution process like humans and they are greedy for power and resources like humans. Otherwise they would have been extinct. I do not know if intelligent species can overcome that and what would follow if some species did that. I think pessimistically that also scientific curiosity is tied to greed for power. It may be that alien without it would care their little gardens and hobbies instead of pursuing higher material living standards or understanding of universe after moderate level.
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The Nova rocket, AKA the other lunar rocket
Hannu2 replied to Spaceception's topic in Science & Spaceflight
I do not understand what you actually ask. Do you think some kind of scenario in which I am NASAs leader in 50's and make a decision between Saturn and Nova? It is practically impossible to answer because I do not know all things which was known then. Probably Saturn was technically and economically much more feasible and significantly faster to develop. It was a space race then and if Soviets would have been first on Moon because my decision, probably my career in NASA had been over. If you ask should Nasa develop modernized versions of old rockets now, I would say absolute no to both. They relied on old material and manufacturing technology and careless economy. It would be much cheaper to develop and use as powerful rockets with current technologies, if somebody really wanted or needed them.- 58 replies
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- nova
- mars by 1976?
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Steam explosions work in space but energy of such explosions are low compared to typical rocket propellants. If he had combined for example few deciliters of hydrazine and N2O4 there would not have been anything left of camera and poor guy.
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Community interest in Gas planet 2
Hannu2 replied to LethalDose's topic in KSP1 Suggestions & Development Discussion
They are late. I think that Squad can not give any sane ideas what OPM mod does not already do without rewriting the whole surface model. Maybe they could put procedurally generated scientifically interesting places based on seed value to make real exploring possible. However, as far as I know, it is against their principles and do not believe they change them. -
Why would you be a terrible space colonist?
Hannu2 replied to Nightside's topic in Science & Spaceflight
My nerves could not stand living with others in crowded habitats. I am not disciplined enough to stay sane and productive in such extreme conditions. I hate risks but like to have good food, interesting hobbies and peaceful family live and I think that no life is better alternative than a bad live without hope that it could change in near future. Shortly, I have completely wrong attitude for pioneering work. -
I thought some low value vessel. For example old barge from scrapping yard. Or maybe exactly defined place 50 m away from barge so that they could have used all navigation and investigation equipment. But probably you are right and repair costs and risks of expensive damage to the electronic equipment was lower than costs and risks of changing things would have been.
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If they knew that success was nearly impossible why did they try to hit to that barge and damage it? Why not some less valuable target?
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It is very difficult, if not impossible, to fit any sane life support to SQUADs numberless philosophy. You can put 12 km/s dv into a ship and eyeball trajectories and avoid thinking math or physics. But you can not estimate duration of such trips. It may be anything from a year to ten years. Or more including rescue missions. Life support must be practically free and therefore futile or some kind of half baked joke where lack of resources shows only some funny message box instead of killing kerbals and ruining mission completely. So it may be better than life support stays as a mod. Now there are several different mods from cartoony jokes to severe micromanagement drills for nerds.
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Other writers told about difficulties of orbital assembly. Other thing is time. It was literally a space race and both participants feared that competitor win the race. They could not think what would be the most economic solution in long run. It is why there was so abrupt collapse of US space programs after Apollo. These solutions was far too expensive to be suitable for any commercial utilization of space and it took decades to build almost everything from scratch.
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1. Axial tilts. Should be self explanatory. 2. Proper mapview-like mission planner tool. It should show positions of bodies and ships at chosen times, have possibility to simulate trajectories over several orbits (for slingshots) etc. It should have porkchop plotter and show chosen orbits in space. If SQUAD will not program every tools it it should be possibility to make such mods on well thought base. After these they should make better seed value based procedural planet generating code make true exploration a part of the game, but I think that it is not in foreseeable future.
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Standard steel from car is practically as resistant as cardboard if you have oxygen rich gas at temperatures typical in gas turbines. Burning through with oxygen jet is a very common method to cut steel in metal industry. Corrosion resistance depends always on circumstances and chemicals. Anyone of so called corrosion resistant steels are not suitable for any purpose. There are hundreds (if not thousands) of different steel grades and those which are able to resist oxygen at more than 1200 K are very rare and expensive. Or in other word, exotic. Typically such dangerous conditions are tried to avoid in industrial processes and where avoiding is not possible, nickel alloys (even more exotic) are more common than steels as far as I know.
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You are correct in defining realism. However, there seems to be a large variation in opinions which things people want to make by a realistic way and which things should be simplified. For example I do not want to make detailed EVAs, piloting etc. mundane stuff. I think that I am mostly a mission command. I plan things, send instructions to crew and make much technical micromanagement stuff to keep things going. But many people have perfectly opposite opinions. They want to make EVAs, pilot by hand, have interior models and they keep planning as a boring thing which should be simplified out of the game. In my opinion SQUAD should make the KSP as a platform which anyone could mod whatever they want. It is already, but it should be maybe more. SQUAD should make a bugless and effective physics engine, UI, career mode basics etc. basic stuff. It is not a bad idea to keep stock KSP cartoonish, numberless and oversimplified. However, engine on the behind of the screen should be made so that the game could be easily modded to even extreme nerdy micromanagement hell for professional engineers and scientists. Or whatever else. Most things are already OK and there are loads of well thought high quality technical realism mods but there are some several problems left. For example map view should have a complete overhaul. Not a graphical eye candy, which is probably already coming, but detailed simulator-like planning tool with built in porkchop plotters, complex slingshot orbit planner etc. As far as I know it is not easy or even possible to mod now. And of course, first of all, axial tilts. They could put kerbin's tilt as 0, Mun on equatorial orbit and KSC at equator, if they think that average user is retard, but angles should be able to change to more realistic and much more interesting values.
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I can not say how long adaptation takes. But it will never be perfect. Typically people learn basic arithmetics during childhood when brains are easier to develop. At least I have programmed over 25 years (from I was 14) and can not use hexadecimal numbers without extra work. Of course I understand values needed typically in programming, and many thing are easier in hexadecimal notation, but if government would change banknotes and price tags to hexadecimal I had to convert everything into decimal system before decisions.
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How many/what mods will you run once 1.1 and 64-bit KSP drops?
Hannu2 replied to GoldForest's topic in KSP1 Mods Discussions
Difficult to say because it opens a whole new world. I have 20-30 mods I usually use but so far I have not used graphical mods except in 0.90 when I played in Linux. I came back to Windows because I felt it important to be able to run other software when I play. I have 16 GB memory and it gives possibility to use nice mods and certainly I will try something. -
As far as I know there has not been any fixes on planets during several versions. Not in 1.1 too. But in my opinion Pol is worth visiting even with a bug. Especially if you can use surface scatterings. Most landings go without problems except annoyingly slow movements in low gravity and stupid timewarp limits.
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Randomised monolith locations
Hannu2 replied to pandaman's topic in KSP1 Suggestions & Development Discussion
I would not like such mission ruining thing. Mission ruining random accidents are OK, but there should be more interesting story and logic behind them. Maybe some kind of large ancient space station which could be investigated. It could give much science and reputation points but also some probability of severe problems (for example illness of crew members, sudden accidents (explosions in modules where kerbals are) etc.). Kicking the ship on the other side of solar system is rather cheap and boring way to cause problems. Unfortunately, as far as I know, SQUAD and most players are against all pseudo random things. But maybe it could be a mod. There is also one problem independent on personal opinions. It would be extreme improbable to hit a point like anomaly on random orbit around Jool. Probably only few of thousands of players would ever encounter it. If the game would not tell clearly what happened people would think that it was some bug. There has been bugs which disturb orbits in some versions. -
What is enough depends on your mission planning. I try to avoid tight timings and do not need more than 3-4 % which is easy to find. If 10 % is not enough and you do not have any construction flaws you need another mining craft of larger one with more drills. As far as I know there are not significantly higher concentrations. Typically there is practically unlimited time to do things in KSP. For example, if I go to interplanetary expedition, I have to stay hundreds of days on target due to launch windows. I land, cruise couple of hours with rover, land on moon, set up mining craft and notice that I have made everything possible before one week has gone and my return window opens after several hundreds of days. In such situation I do not care if mining lasts 2 days or 200 days. Concentration of 3-4 % is more than enough then. I can always use timewarp and get tanks filled in few minutes of real time. If I have refinery on Minmus I have hundreds of days between launch windows to planets. It is again indifferent how long it takes.