AngelLestat

This happen a very high altitude, where the atmosphere density is so thin that only climatologists may find interesting. It seems that at lower altitudes the values remains the same.

The problem is not related to the amount of hydrogen that venus has vs the population needs, is more related to the cost of get it, I still think that collect sulphuric acid rain at 47km and then split the water from the sulphur would be way more cheap that get it from space, even taking into account future technology. You can also collect pure water from 30km altitude using condensation, but no sure which would be more cost efficient.. There is a third option to get the water from ground aquifers as in earth. But we dont have data on how deep or the amount of water we can find, we just know that there is ground water due volcanic activity. About asteroids, I would use them as fuel depot in orbit, so you don't need to rise the hydrogen and consume extra to leave venus low orbit. Like this idea in TED talks, which seems better than my initial idea of painting the asteroid. https://youtu.be/wLMHcUg36yc?t=3m39s PD: Also dont think that the amount of water is fixed, first that sphere of water is more than enough to support our population and much more, people will also recycle water, and even if you can not recycle all (due different uses) it does not disappear, it stay in the planet. Venus is also always losing hydrogen due solar pressure, but it also receive hydrogen from volcanoes and hydrogen and matter that fall from space.

We agree in this point Nope.. you are still in protection against piracy.. although as I said, you should have your own private security. But none threat to your city can take much time, because you will get help from any country, because piracy is considered a threat to everyone, so it is a factor that all the world agrees to fight. http://www.judicialmonitor.org/archive_spring2011/generalprinciples.html Expenses (not sure if it is the right translation), no rent.. and is not the same. Because there a lot of things that you are not paying for, that a country needs to. Nope. http://www.straightdope.com/columns/read/2250/in-international-waters-are-you-beyond-the-reach-of-the-law Extra source with less words: http://www.funtrivia.com/askft/Question52490.html Your country jurisdiction still counts. Costa concordia captain was sentenced to 18 years of jail, by its own country jurisdiction. And in any case you want to provide more confidence to your habitants, you can create a contract to ensure that any lawsuit or crime should be managed in certain court of the chosen country.

Countries had taxes.. this will be private, because nobody will recognize this as a country, there is also no benefit to try to pursuit that claim. You just need to paid expenses, or rent (if you are not the owner of your department or house). Inside the expenses comes the maintenance, security and other services. People living this place are still citizen from their respective countries, so any injustice should be treated in those. You can have private education and different things.. so tax are not required. By the way.. I mention in the cons that there are many drawbacks that counter most of the pros.

Floating sea cities, had some pros and cons. Pros: you dont need to pay taxes or land, you can be outside of country regulations if you are in international waters (which might bring some investments) Cons: extra cost to protect from corrosion, sea life, waves (once you stop the full wave in the edges 15m wall, it does not continue under you) and good anchors to resist hurricanes. It is all doable but it counter in some way your pros. Things that are no pros neither cons: You dont have easy access to land or close cities, at least you leave very close with a permanent bridge to connect your floating city, in that case you lose some benefits but you also lose some drawbacks. You get an average of cheap products if you allow free market, some products will cost more because you are not close of nothing or with easy access, but all the product that require seaships, those would be cheaper. Your city should be large enough to guaranty that you cover most of your people interest. But a vertical land city should be cheaper.. because the cost of land is not high if you build up. ----------------------------------------- A floating atmosphere city should be possible in earth, you need to have a minimum altitud of 6000m and with kite gradient propulsion to dodge mountain ranges. I know how can be build such bring city without hangar and dealing with wings.

Point taken, my idea was a fixed platform, but I forget about different launch inclinations. I will like to know what are the most common path. They are looking launch a rocket each week.. your seven days example is still far in the time. Nobody said nothing about relaunch from a platform.. in the platform you can have a crane to move the stage to a special boat which will carry that to a special port close to launch site. In this case you move a ship and not a whole platform or barge, because that small barge will not be enough to guaranty safe recovery of the stage and the barge. And if you increase the barge area and stability, not sure how much will be the cost of that + move and operation. A fixed concrete platform is cheap, maybe you can have even 3, you just need to adjust a little more your fuel reserve. It could save days if they have an special port to unload the stage close to launch site. Avoiding in the future all the refurbish and testing inside the hangars. If they increase launch rate, those operators will be equally busy.

the stage would not break in the middle, is a lot more robust than that. If you can place all the weight in the extremes (edges) of the trailer, then you just need wheels under those points, which decrease the friction and it is easier to move and turn. It has enough wheels to not break the street.

That is the time it takes today (first try), when spacex not even have scheduled and planned its logistics on that matter. By the way, that can be easily solved with my fixed solid sea platform proposal, which also reduce the cost of faring recovery and increase the chance of stage recovery in any weather.

the transmission is one way.. You can not send commands or instructions to the sails, and even if you can it will be pointless.

As i comment before, if you use lasers (instead of radio waves) to communication, then sails will act as a parabolic mirror in where you can place a photon receptor in the focus point. You can turn your receptor to just a very narrow range of frequencies to avoid noice.

I imagine you get that info from this blog: http://www.thegeektwins.com/2010/05/flawed-science-of-avatar-floating.html There is a lot of people wanting to look smart just criticizing everything they found. But the problem is that they took only 5 to 10 min to reach a verdict, sometimes with the first evidence (or flawed logic) they found. If there is a problem you want to solve, is easier to found variables or circumstance in where it does not work, harder is to find in which range of circumstances will work. In that blog, he does not make any math, he does not have anything to compare, he just make his verdict in a site which science is a weird topic. Here there is another dude that tries to make their own calculation reaching a value of 6 tesla. https://www.quora.com/Would-the-floating-mountains-of-Avatar-really-be-able-to-float-If-so-how But I believe he is also wrong.. I can not prove it with math because I don't know so much on superconductivity and magnetic fields. He takes into account just the field pressure in unit of area, like if only the mountain-block base area is the only thing that matters (I am not so sure about that) this mean that after that the field disappear? no.. because is conservative. That formula takes into account the left or right scenery? What if you have more superconductors above? Those does not generate quantum locking? why? Is the magnetic strength (tesla) what matters or the field intensity (amper/meter)? Here is explained the difference between those effect (meissner and Qlocking), which are also related to (type 1 and type2). https://en.wikipedia.org/wiki/Flux_pinning "On a simple 76 millimeter diameter, 1-micrometer thick disk, next to a magnetic field of 350 Oe (28000 amp/meter), there are approximately 100 billion flux tubes that hold 70,000 times the superconductor's weight. That same disk, if made two milimeters thick could support 1,000 kilograms, the weight of a small car. In a superconductor three inches in diameter, there exist an estimated 100 billion flux tubes when placed over a magnetic field." So if each piece of superconductor can support its own weight and more in a decent field strength, why the mountains can not float? Jupiter has a magnetic field that goes from 1Tesla=10000gauss to 10 gauss (orbit), earth magnetifc fields goes from 0.25 to 0.75 gauss. http://hypertextbook.com/facts/1999/AleksandraCzajka.shtml Someone may said, the mountains are far from surface, but comparing with how far the magnetic flux travels, that distance is like 1mm or less from a normal magnet. Well, I hope someone with real knowledge on superconductors solve this issue, the parameters to have into account are: -% of superconductor material in the mountain, gravity and magnetic flux. -If the planet is cold enough we don't need hypothetic materials. -A planet with superconductor materials would have a powerful magnetic field. -Magnetic flux can travel from a moon to the planet and back (tidal lock)

Like everybody said, on the matter of attitude control does not pay off, neither in higher orbits. They can work to increase or decrease your apo or periapsis, but if you need to rotate your craft (when you are already turning around earth, which increase your attitude accelerations needs with a constant sun angle changing), then it does not have any sense due its low acceleration and the increased complexity of the maneuver. But if we talk about a solar sail orbiting the sun then everything changes.. Here is possible and useful to use a solar sail like attitude control and propulsion. Because you have a lot of time to react between orbital periods, even if your orbit is super close to the sun, your acceleration to make any maneuver also increase a lot. Basic solar sails maneuvers: You can go in any of those directions, your thrust is always normal or at 45 degree, in this next image we can see how the solar sail angle should be pointed to lose orbital speed and reduce your periapsis. Solar sail control in planet orbits is possible (with some drawbacks), there is books about that.. but too complex if you just need attitude control for earth sats.

Yeah, It could be used as attitude control over the whole trip, but not sure the amount of energy you will need to waste in this matter, because you need to turn on and off the charges in the wires, so even if you use superconductors does not help much.

If there is something as unobtanium (super conductor at earth temperatures) or normal superconductor material in a planet that is cold enough to sustain that effect, then you only need a high magnetic flux... then yeah.. it can happen.. Chances increase if this planet is like the one in the movie, orbiting a gas giant (magnetic flux between the two, both tidal lock).

Ok, not sure if I follow you.. how can you accomplish the same thing in a spread area? Not sure what evidence points the 2 maps.. because we can not compare different country politics and conditions. ok, but terrain cost increase all the time (because population and the PBI of each country increase). We can also compare the cost of terrain in a city vs the outsides.. the cost increase a lot, why? because the benefits to live close to everything also increase a lot. What is "A single, fat?" A cow or a pig? or something else? Also meat is easier to transport due its big density. In my example I detail that is 30 to 50% from the productor profit, so if 1 ton of corn has a production cost of 100$, and the productor will sell that to the distribution center at 170$ and he has a 50$ profit for each ton, then it means he paid 20$ to transport that ton to the distribution center. That example means 40% of transport cost from the productor profit as I detail in my first example. Then you need to add the transport cost from the distribution center to the different stores. Of course if you need to do only 100 km the cost would not be 20$, we are talking about an average of 300km + taxes. Because some crops only occur in certain climates, these means far distances from your location. heh, nice. I imagine you live in the west, Arizona or California, above 1000mts ? What are El niño effects there? Yeah they have a lot of info on people interest and trends.. they can include all that in a massive neural net to learn and predict that.. but the algorithms are hard and the amount of data huge, so I guess this will be possible within 7 to 10 years.

What you mean by station keeping @Errol? Low orbit altitude with geosynchronous speed? Just attitude adjustments? Equator or Pole? Of course a solar sails can not float if the light comes from behind. This is a possible polar orbit for solar sail: The yellow cone is just to show that certain instrument can monitor that zone 24/7. To float over the pole without orbital speed and counter earth gravity, you need a solar sail density of 0.01g by m2, which may be achievable within 7 years, you also need direct sunlight (1366w/m2 all the time), so in practice you will have some orbital speed as the shown in the picture with lower density requirements. You get 6.7 Newtons by gigawatt. A solar sail for example can be very usefull as early warming against solar flares, because you place the solar sail in mercury distance (or closer) but with the same orbital period than earth. But still not sure to understand your question.

I will not put my money on it. They are lying in many aspects according to their numbers in the official page. The swept area is what matter most, like you can see, in a wind turbine the tips of the blades seems tiny, but they move so fast that they convert almost half of all the energy generated. Normal wind turbines reach 40% of efficiency in a decent range of winds, this vortex pole only can work in few wind conditions if it wants to take advantage of resonance. They claim that it would be so cheap that you can make 3 for the price of one, but even if that is true, they will still harvest less energy (due kinetic conversion and swept area). MIT critics are also accurate. I can not help you with vortex wind calculation, you need special fluid software for that because there is no way that you can make a decent estimation with a formula, but you can calculate how much wind area swept and what is the conversion kinetic efficiency, the kinetic to electricity efficiency, the range of winds that it works.. then you have a more approximate number. Just take as granted their kinetic wind conversion efficiency.. and start from there, you will notice that even with their numbers, does not have sense. About wind energy future, I bet on Kitegen, even if the kite area does not seems much, but the swept area is a lot, because they travel at 70m/s or more, and the wind speed at higher altitude is constant and stronger.. like you can see what matter most is wind speed in power generation, because increase with V3 http://kitegen.com/wp-content/uploads/2015/05/KGV-S.p.A.-Presentation-ENG-1.pdf http://www.kitegen.com/pdf/dossierkitegenen.pdf Google has their own wind airborne technology with Makani, but I like more the kitegen approach.

Population growth is not related to country development. Environment and pollution.. Any south american pollutes less than the average citizen from development countries, even adding the amount of clean sources they might have, if we are talking on clean technology %, I have to admit that Argentina is very delay, because we just go out from a bad government that last 12 years, lucky for us we made a good change this year. But Uruguay (our neighbor) is the country with higher % of wind energy in the world. Chile and Brasil are fine too. As I describe.. any country has terrains that convert for residential or other uses, there is no need to change current infrastructure, cities are always growing, so you can start from there, new villages or towns appear all the time in places where before there was only a cropfield, if you sell those lands and you give them structure and organization, you increase the profit. We have a lot of car factories here, that is what it matters, you will said that Iceland is not a high developed country because they don't have its own car brand? Brands belong to private investors, and those does not really care about country limits. We can not compare on production or PBI of each country, because for example USA has 7,6 times more population than Argentina, with 3 times higher salary (in average), Brasil has the same salary than Argentina, with lower population than USA. We can said we have a delay on salary range.. which may reduce some of the infrastructure, that is true. But from the context of this discussion we have access to the same technology than any first world country. No, I am not making that assumption, these are my words: "for each individual there is a higher chance to choice the best cost efficient option" It does not matter if some choice different.. what matters is the common trend. Heh are you sure that economist will argue that? because I learn this argument from 2 economist view and other sources, but well you seems to agree in this point.. but not sure if is due irrational behavior.. it is because is too complex, even if all decisions are rational, due offer, demand and trends.

@DBowman ask if the solar wind travels at 600km/s then that is your max speed? I guess it is.. Unless you have a high energetic solar flare with photons close to the speed of light, but it would not be enough time to increase your speed much. They seem easy to deploy and cheap.. but I guess the wires should be covered with a reflective layer, so you can use superconductivity to keep the charge without waste extra energy and keep the wires diameter thin to improve thrust/mass ratio. About your final speed @PB666 , not sure if I am wrong of technology or you are.

@PB666 Lets start from the base that solar wind produce 5000 times less pressure over 1m2 mag sail than photons (1360w/m2 normal irradiance at earth orbit) over 1m2 solar sail, a normal sail if is not designed to work like a magsail, the charge is not the same, would not do much.. the force and effect is negligible. The benefics with electric sails is area, they are also very good to kill relativistic speeds, not so much low speeds, a craft traveling at 0.95c, it may take few days to brake to 0.5c without propellant. That is why I consider a good idea to include some charge wires in a normal sail, so even if is not enough to brake, your time in the system increase. About your concave shape concern due pressure, you dont need to transmit inside the solar system, and shape will be easy to control if you add some contraction rings over the sail, that it will contact when a electrical current is applied. (Ok now I read your next paragraph and you had a similar idea). You mean a continue beam? I did not understand the part of "once at the center they search out other ships, which then can send signals out in parallel each ship sharing data with the next and each ship gathering its own bit of science". Choramatic light in the edges of the beam is not possible, because all beams diffract, in no time you have that chromatic light in the center of the beam and way beyond the edges.

Is hard to keep the speed of this topic. Yeah, those 5 to 8 will be like minimun, with also few areas at ground level to let enter the sunlight, but you will have also another continue surface at the 8 floor level where you can see higher structures rise from that. There are two ways to do this.. one will be with construction rules, anyone can make their buildings but fulfilling all integration rules that the city requires. The other way is like you mention, the state is always in charge of common infrastructure, in this case the common infrastructure would be a base structure design for all the city (just for vertical support and to deal with smart resource management). That way will be more uniform esthetic, it will require higher taxes and lower investment from the private sector. OMG O_o XD, what are you two saying? 30 to 60 years behinds?? 1940? south america? hahahaha.. This was an answer to my country example? If it was, that is clear lack of info about the rest of the world. We have the same things you have.. the only difference is average income.. we earn 3 times less in average, we save money in other things but we keep our technology thirst the same, that's it. In fact, development speaking we may be even more advance in farming technology and machinery, we are at the same level of spain in health research. Yeah you may have some people living as many years ago far of cities and in remote locations, but this also happens in USA or in the whole world, does not apply to the whole country or region. You are making a common mistake.. try to view economy as a whole aiming to understand it or predict it is pointless. You cant, nobody can! What science does to understand things? They divide the problem until they find the basic pieces and principles, then understanding that, they can make predictions (inside a certain frame of reference (who does not contain much variables). Economy is the same, no even a computer (today) can predict the consumer choice and the strategic decisions of each individual on the world.. So if we can understand this problem from the basic principles of economy in which for each individual there is a higher chance to choice the best cost efficient option and then generate extra profit with that (because it saves time or money), and with that extra profit it generates work and profit to others, then we can start to understand how economy works, we can even compare with reality, we have many examples of new breakthroughs or changes who bring profit to the whole world... then there is no reason to think it will be different this time, because new opportunities and works always arrive (if it happens at a decent human speed), a very different thing would be the development of an AI. Which it happens super fast, and from 1 year to the next people discover that an algorithm can replace and take better decisions than any other intellectual job, so we lost our purpose more than a job. Ok, example number 1 did not work.. I will try in a different way. This is similar to the case of predict how many coins will fall head or tail. If you drop 3, there is a considerable chance than 3 fall head, or the 3 tail.. But if you increase your coin number to 1000 for example, you will be able to predict with enough certainty that 45% to 55% of the coins will fall head. That amount of certainty is what allows you to calculate your storage needs without overstate, to not delivery a lot of power, etc.. For each good and services. I made those calculations a lot of times, believe me, because another extra cost comes from investment (credit) and payback time, You can reduce by 10 times the cost to accomplish the same thing in some cases, more if you add other services and products. Houses also need foundations, the amount needed for each case like buildings depends on the type of grounds, if you add the meters for each single house, you end up with a similar amount of meters for the whole building replacing all those homes, also each time buildings are lighter and industrialized, as the one planned in China, tall as burj khalifa (but much bigger) and it will be made in 1 month. But it has nothing to do with Argentina, because almost all foods are cultivated here, the only difference may be taxes, that are considerable high here, but in world average.. 30% to 50% of transport cost has to be normal, then we need to add distribution cost and seller store cost.

These sails will have a diameter of 1 to 4 meters, that can be used as a descent parabolic, the parabolic will always point forward, with a light receptor in the focus point, then you relay that transmission with a laser to the next sail, these sails are 99.999% reflective, they only need to get few photons with a complex error proof algorithm, and they dont need to achieve high bandwidth because their instruments will be simple without much resolution. They transmit only in one direction, so is not a connection link. You can not sent info or ask anything. The normal distance between sails will be neptune to earth distance, but they should be able to transmit 5 times that distance in case something happens. They want to keep this project between the 100 billion margin, if you need 1000 times that power, it will also increase a lot that budget to the point that the government and investors will just said "no". And we get nothing.. Maybe there is a way just increasing a bit more the laser power and sail area keeping the budget low reducing the amount of sails you sent and increasing the acceleration time with extra laser in the way and using mirrors to get multiple bounces of the photons when the sail is closer to the laser. In this way you place low powered lasers over all the way from here to mars orbit, but allowing to bounce the light in each laser around 100 times. Then you include a tiny wire in the sail that it will work as mag sail to be used as brake to at least reduce the speed from 20% c to 5% c, then you make a close dive with the 2 stars from the binary system to slow down the 5% leftover and stay in the system, going to any planet you want (because it also works as a solar sail). If the sail is bigger, it can transmit over higher distances and even receive commands.

That is the easy part.. the hard part is to self focusing the sail inside the beam, you could do that with special shape as I said like this but less drastic: http://www.centauri-dreams.org/?p=33450 It does not matter the material, but I found the original site of this project (when i was searching for an quarter wave example for you), here is explained: http://www.breakthroughinitiatives.org/index.php?controller=Forum&action=viewforum&id=5&page=1 Graphene is also in consideration, as you can see you can make a mirror with different techniques, holes quarter wave, or quarter wave dielectric way. Almost everything you need, each sail has a different science instrument, lets imagine than the first 100 ships had a camera, then you can use another instrument in the next 100 ships

ok, right, but the context was just: big uniform accelerations = no damage.. They need to bounce or it will evaporate due heat XD That is the easy part, you can choose the frequency of the laser, so if you make quarter wavelength holes in the sail, the light will bouce at 100% if they are perfect, or 99.9 if they are not (but that it would be enough to survive. I was reading in some sites, it seems the sail is 4 m of diameter.. or 4m2, not sure. One thing they dont mention, is that they need to make a special shape to make this sail self focus (auto riding the beam), if they get close to the edge of the beam, the shape and reflection force the sail to stay in the center of the beam. Maybe regulating the spinning speed can be accomplished. I guess they will use micro nuclear components

I know the spaghettification effect, but I did not give distance or black hole mass neither acceleration, because I just wanted to make a point that is not related to black holes. But well, if we are talking of prevent spaghettification, then we need big black holes, at certain distance outside from the even horizon (so we dont have problem with no proven theories) to produce huge accelerations without any harm to the subject (with a no active black hole, so radiation is not an issue neither) Happy? XD Lets see: F = 2P/c (photons bouncing force) F= 200000000000 / 300000000 666 Newtons This give me 1.13 grams.. (maybe you forget to multiply by 2, due bouncing) But not sure if this value is right.. it seems very low.. You are sure the power requirement is 100 gw for the laser?