what kind of space mission would cause the same buzz as apollo?

[BrianHG]

Nice perpetual motion machine they have there! Are they actually serious?

I would expect that any tidal effects in a 40,000km long ring would rip it all apart. It would also be inherently unstable - any slight deviation from perfect will cause thing to do downhill very quickly.

How do people get the money and time to propose such things?

It's not perpetual, it requires energy to keep the inner ring spinning.  This is not about cheap, it's about what's possible with today's materials and known physics.  Launch costs aside, it is still easier than a space elevator which needs a material longer than the distance to geostationary orbit with a cable with the tensile strength to make it that far.

Quick back-of-the-head calculations, ignoring that the whole thing would be dynamically unstable...

- Carbon fiber density is about 2 grams per cm^3

- A 1m x 1m box section, with paper-thin (0.1mm) walls is about 5cm^2 in cross sectional area, so would be about 0.8 kg per linear meter. Call it 1kg per meter, or 1 ton per km.

- The earth's equator is 40,075 km - 40,075,000 m.

- The weight of a paper-thin 1m x 1m box section to go around the world is 40,075,000 kg.

-  Falcon 9 can lift 22,000 kg to LEO, at a cost of $50M per launch. Assume that all of this payload can be used to build the ring.

- It will take ~1,800 launches, at a cost of $90 billion, to get the raw material for a 1m square paper-thin orbital ring into Low earth orbit.

Once it is built and you have 40,000 tons in orbit. You want to speed it up to support any wright that may be  'hung' from it.

Because centripetal acceleration is  f=v^2/r, you have to move something 1.4x as fast to speed to double the acceleration/force. Low earth orbit is ~8 km/s, so this 40,000 ton paper-thin structure would need to be accelerated to ~11 km/s.

After all this work, each meter of of ring would only be able to generate 1 kg of 'lifting' force. It it is at altitude similar to the ISS, the lifting force from 400km of ring would be needed to support the weight of a 400km box section that touches the ground. 

-

     Your figures aren't too outlandish, especially for a project which we could only begin to realistically think about 50 years from now, begin construction 100 years from now, given the growth of reusable rocket technology, the number of launches which are currently going up and up.  Especially if in the intern we get an intermediate launch assist technology, or, mine the material from the moon's surface and ship it to earth orbit.

[BrianHG]

Changing inclination is relatively expensive, especially when done at higher speeds. LEO is rather high speed in that regard. Higher orbits are much more efficient. Once you're up there, getting around is much easier.

Sure, but it doesn't make the Orbital Rings any more feasible.

Add another 5,277 tonnes of material to this 1m x 1m x 40,000,000 m hoop, pushing the ring out from 160km to 1,000km above the Earth (just about where the radiation belts starts - any higher and you will be in an intense radiation zone). This reduces orbital velocity a little from 7.8km/s to about 7.35km/s. Even though it is slower it still takes more energy to lift material into this orbit, and now the towers used to access the ring need to be 1,000 km tall...

I'm only interested in the ~100km altitude orbital ring.  At this altitude, once creating the stationary deck, it is much easier to gain access to Earth's surface and you get a near vacuum track to accelerate space launch vehicles.

[apis]

The romans had sewage systems, running freshwater, multi story apartment buildings, etc. Then it all collapsed (politically), the library of Alexandria was burned and the clergymen took over... It took almost 2000 years before any city was comparable. After that it didn't take so long until people figured out how to build steam engines and flying machines. Imagine if the romans would have kept going. What's holding humanity back is mostly politics and human stupidity, not physics.

[Nominal Animal]

I'd like to hear more about this -- I know single-crystal castings are used with superalloys for extremely demanding purposes, e.g. turbine parts.

That's essentially what those natural gas pumps are. If I recall correctly, even though they're milled from one chunk, the individual blades hang freely from the hub; the RPMs are so high the centripetal effect will keep them rigid in position. That way, small, inevitable shocks to blades, won't cause cracks to the blade-hub joint (as there is none). Funky designs.

"Reactive" or "self-healing" reactor vessel surface materials are another avenue: the idea is not to avoid individual defects, but handle them, and stop the defects from clustering and forming macroscopic faults.

The Fe-Ni-Co-etc. superalloys are homogeneous (solid solution) alloys, so this works nicely despite the large alloying percentages.

I'm not familiar with nickel alloys, as its outer electron interactions with other atoms are difficult to model with EAM (although I haven't evaluated the Demaske et al. one published a few years ago); with chromium, using two "bands" of electrons in EAM works surprisingly well. I did some work on modeling ferrochrome, especially modeling how the chromium is distributed (as a function of distance to surface) in molecular dynamics simulations, using multiband EAM potential model; for better understanding of certain types of corrosion resistance.  It is surprising how much individual atoms migrate even at room temperatures.

(That's also where I got my spark for a new generation of MD simulators. When the affected depth is on the order of a micrometer, and you need some surface area too, the atom count becomes large enough (hundreds of millions) so you start looking for both better ways of combining different types of simulations to fully explore the phase space, and how to get more computation out of existing hardware.)

In normal aluminium, small lattice defects often act as seeds for macroscopic defects. The hard oxide layer that naturally forms on the surfaces gives pretty good corrosion resistance, but in those turbines and RPMs (IIRC 20 kRPM for a one-meter diameter turbine? Can't remember details) any macro-scale defect means the turbine will simply rip itself apart. Heavier metals cannot be used at such high RPMs, because stress and forces would just rip them off.  I'm not sure about amorphous materials, but I think none have the tensile strength to weight ratio to beat aluminium (and not erode too fast in the corrosive atmosphere). The g-forces at the outer parts of the blades are downright ridiculous.

It'd be interesting to try and model alloys where the constant stress (at moderate temperature) was used as a tool to strengthen the material. The acceleration causes a significant gradient in the lattice tensions along each full blade.

Is it really worthwhile to make a single crystal with what little will dissolve in it?  Once made, though, I can see precipitation hardening being very effective.

As I understand it, purity is not an issue (that is, a tiny amount of impurities isn't a problem), but any kind of grain boundaries would just act as seeds for macroscopic defects to form, leading to catastrophic failure.  So, by monocrystalline, I don't mean 100% pure Al, but a 100% regular lattice structure. (Yeah, ninety-nine point something...)

Also a bit surprised that something more conventional isn't used, like Inconel, maybe with a plating like pure nickel, or a ceramic coating or something.

The acceleration at the blade tip is something ferocious. Aluminium is light, about 2.7 g/cm³; Inconel is what, 8+ g/cm³? Just to keep the blades intact, you need triple the tensile strength to account for the higher density.

The corrosion resistance might be better described as erosion resistance as well. With aluminium, the turbine blades and pipe walls can have a layer of "extra material"; basically extending the lifetime of the turbine by allowing some corrosion/resistance.  IIRC, their lifetimes are between half a year and five years, depending on several factors.

(I believe all specific figures and information is sort-of trade secrets; I only found out enough to understand what kind of simulations would be needed to be useful.)

[In Vacuo Veritas]

Silly man

yet it moves.

Yes, someone made a sketch once. Therefore, all sketches must become real.

And this is what passes for "intellect" amongst you lot?

So physics doesn't limit us either.

Wow. Just wow.

Brainless religious zealotry.

[In Vacuo Veritas]

Once you're out of the atmosphere you can use skyhooks to move up and down in the gravity well.

Oh of course, of course! It's all so simple. I suppose I can buy these on McMaster-Carr, right?

 

You know, if you ignore reality, this is all so easy!

Just use a skyhook! 

How much you wanna bet that in ten years, absolutely nothing will have changed, except the fervor and froth from you lot with ever more outlandish and impossible scenarios?

[apis]

Oh of course, of course! It's all so simple. I suppose I can buy these on McMaster-Carr, right?
 
How much you wanna bet that in ten years, absolutely nothing will have changed, except the fervor and froth from you lot with ever more outlandish and impossible scenarios?

Who said anything about ten years? You keep making up straw men, and not very good ones either.

You know, not too long ago you there wouldn't have been a McMaster-Car where you could buy anything. Things have to be invented and then designed and then built. Ten years ago you would have said the same thing about reusable rockets, can you buy those at McMaster-Car? It's obvious you don't understand how the world works or basic physics. There's a lot of ongoing research being done on tether systems.

So physics doesn't limit us either.

Reading comprehension isn't your strong suit either obviously. Physics isn't the bottleneck that is preventing us from undertaking big projects, like replacing fossil fuels. But I'm sure you think that's impossible as well. If it was up to you we would still be using stone tools and fire would be considered untameable.

If God intended us to fly he would have given us wings.

 

[coppercone2]

how much would a string of carbon nanotube that is usable for construction of the space halo thing weigh if it was elevated from a platform 50,000 feet in the air (maybe it would cut down on wind load and shit) to a usable space factory in a position orbiting the earth at the same speed as a aircraft (idk, 1000 km/h)?

how many  watts would you need to power enough 70% efficent ion thrusters to keep the factory from being pulled down? How much power would a electric winch need to reel it in ? what is the flow requirement to get a useful amount of material into space for manufacturing?

[BrianHG]

how much would a string of carbon nanotube that is usable for construction of the space halo thing weigh if it was elevated from a platform 50,000 feet in the air (maybe it would cut down on wind load and shit) to a usable space factory in a position orbiting the earth at the same speed as a aircraft (idk, 1000 km/h)?

how many  watts would you need to power enough 70% efficent ion thrusters to keep the factory from being pulled down? How much power would a electric winch need to reel it in ?

Standard steel/iron cable is sufficient for the ring.  Remember, the inner wire ring is spinning at standard orbital velocity as well as the outer platform when under construction, so, there is not gravity.  It would just be like a continuous space station around the earth with an inner wire core not connected but magnetically suspended like magnetic bearings.  Next, as you add magnetic power, like a linear motor or maglev train to accelerate the inner core, the outer platform which has the electro magnets doing the pushing begins to decelerate. This inner cable, like a suspension bridge cable, will begin to have an outward force as it accelerates above orbital velocity, however, the platform deck with the electromagnets doing the pushing becomes heavier as it slows down below orbital velocity loading the outward force of the accelerating inner cable.  (Nice and balanced)  Electrical power is initially required to change the speed, then a small amount is only required to maintain and regulate the speed as there is no friction other than magnetic eddie currents in this system.

Orbital rings is not a new idea and it has been well though out.  However, like the narrator said, this type of project will require a world wide investment in it's manufacturing and development with the vision of easy access to space and with world politics, this is currently out of humanities will, but not outside our technical capabilities with today's materials.  No new magic physics, no perpetual motion, carbon nanotubes cabling, or anti gravity needed.

[coppercone2]

no, I mean just a platform designed to reel in material to make a ring with later. how would that look like in regards to my questions. I would imagine you need very large amounts of material to make the ring.

you need to start with something and I feel that rockets are not a good way to bring that much shit into space. a counter weight seems hard but active propulsion may be viable with nuclear power.

unless you can reliably haul in a single strand of steel into space to build it with in the same way. I think the way to go would be to make a platform that can haul enough material in there to actually make a ring, then to stop using that and just use the ring if its feasible.

You can crash a nuclear powered jet into the ocean and a space platform can be built to disintegrate and a single strand of carbon fiber reaching to however many kilometers should not pose too much of a hazard as it falls down.
I think the power consumption of the factory would depend on fast its trying to pull in building materials.

 Maybe there is a reasonable number for accumulation of materials into space and steady state power consumption that makes electronics and everything manageable. 

[T3sl4co1l]

That's essentially what those natural gas pumps are. If I recall correctly, even though they're milled from one chunk, the individual blades hang freely from the hub; the RPMs are so high the centripetal effect will keep them rigid in position. That way, small, inevitable shocks to blades, won't cause cracks to the blade-hub joint (as there is none). Funky designs.

"Reactive" or "self-healing" reactor vessel surface materials are another avenue: the idea is not to avoid individual defects, but handle them, and stop the defects from clustering and forming macroscopic faults.

Yeah, that helps a lot too.  Bottling pure fluorine in a steel cylinder seems a bit... unlikely, but turns out it works, at least under the usual circumstances.

Guessing the difference with aluminum is, sulfur (and whatever other relevant unpleasantness, as far as transition metals are concerned) has a similar inert-ing effect to oxygen, so it behaves nicely.  Al2S3 is a fairly refractory ceramic as such, shouldn't diffuse around much.

Maybe wouldn't think titanium (or other valve metals) would be too bad, and its strength to weight ratio is much better than aluminum.  But, it's also known to be sensitive to stress raisers IIRC.  I forget if they use titanium, or superalloys (or what else) in jet compressors...

molecular dynamics simulations, using multiband EAM potential model; for better understanding of certain types of corrosion resistance.  It is surprising how much individual atoms migrate even at room temperatures.

Ah, so you were involved in surface chemistry research on this stuff?  Neato.  Hard stuff to figure out.  I suppose we're somewhat past the point where empirical testing is practical though...

It'd be interesting to try and model alloys where the constant stress (at moderate temperature) was used as a tool to strengthen the material. The acceleration causes a significant gradient in the lattice tensions along each full blade.

Gradient alloy maybe?  Something with crystal transformation under stress?  (Stabilized zirconia comes to mind, what is it, cubic with a strain transformation to tetragonal?  Shape memory alloy however would be the wrong way to go.. )

As I understand it, purity is not an issue (that is, a tiny amount of impurities isn't a problem), but any kind of grain boundaries would just act as seeds for macroscopic defects to form, leading to catastrophic failure.  So, by monocrystalline, I don't mean 100% pure Al, but a 100% regular lattice structure. (Yeah, ninety-nine point something...)

I mean, that makes even less sense, because pure aluminum is almost as soft as sodium.  Strength to weight isn't going to go anywhere...

So it would have to be precipitation hardened, no?  You'll get some amount of concentration gradient as the alloy freezes, except for very similar elements (probably Mg, Si, Zn and not many others?), which will make consistency difficult.  Unless it can be done in just such a way that it helps with the stress gradient, as mentioned.

The acceleration at the blade tip is something ferocious. Aluminium is light, about 2.7 g/cm³; Inconel is what, 8+ g/cm³? Just to keep the blades intact, you need triple the tensile strength to account for the higher density.

Well, there you go, it's easily 3 times stronger than any aluminum alloys I know of.   Unless there's something crazy going on with the single crystal structure.

(I believe all specific figures and information is sort-of trade secrets; I only found out enough to understand what kind of simulations would be needed to be useful.)

[BrianHG]

no, I mean just a platform designed to reel in material to make a ring with later. how would that look like in regards to my questions. I would imagine you need very large amounts of material to make the ring.

you need to start with something and I feel that rockets are not a good way to bring that much shit into space. a counter weight seems hard but active propulsion may be viable with nuclear power.

Agreed, if we are stuck with rockets, our best solution is getting mining and manufacturing on the moon, then shipping those manufacturing materials to earth orbit.
As on the moon, it's size, gravity, and lack of atmosphere allows for a linear motor type maglev train track to accelerate a cargo vehicle off the moon and into earth orbit for a fraction the expense of getting anything out to earth orbit.

[coppercone2]

no, I mean just a platform designed to reel in material to make a ring with later. how would that look like in regards to my questions. I would imagine you need very large amounts of material to make the ring.

you need to start with something and I feel that rockets are not a good way to bring that much shit into space. a counter weight seems hard but active propulsion may be viable with nuclear power.

Agreed, if we are stuck with rockets, our best solution is getting mining and manufacturing on the moon, then shipping those manufacturing materials to earth orbit.
As on the moon, it's size, gravity, and lack of atmosphere allows for a linear motor type maglev train track to accelerate a cargo vehicle off the moon and into earth orbit for a fraction the expense of getting anything out to earth orbit.

but like I said what about just making a space platform with a bunch of ion thrusters and a winch on it to reel it in from a airplane that follows the platform and accumulates it with some kind of capture system from cannons or midair resupply.

do the numbers look ridiclous? a ion thruster is like 70% efficient so it can counter act the pull. It could be powered by a nuclear reactor at first but I think you can make CNT solar panels and batteries? to eventually make it powered by solar electricity alone. then it would just keep reeling in stuff to build the orbital string.

is there a moon requirement for sure? it complicates stuff. You can attach whatever is needed to the string in small amounts so it can be scraped off or chemically removed or whatever to bring materials into space.

I imagined electromagnetic cannons shooting stuff near the flying plane so it can stay supplied cheaply. Like those air planes they put in blimps in WW1. You could even make it a pulley system to just continuously bring up whatever materials can be attached to the CNT in small amounts. I mean you can get a gallon of milk out of a bottle with just a shoe lace if you were desperate.

If its up and running it would be a continuous flow of whatever is needed that would not have high maintenance requirement other then the plane, but maybe that could fly for for a while before the hydraulics wear out or whatever problems planes develop. It could be built better then military disposable nuclear war stuff.

Like a conveyor belt tensioned by ion thursters and a nuclear powered airplane.
Or it could just be used to keep bringing carbon ropes into space without a return cable to recoat or whatever.

then when you get enough solar panels on it you can relocate it to a geostationary orbit point and get rid of the airplane and run it from a base.

[T3sl4co1l]

NEO asteroids are less dV than the Moon (AFAIK).  A source of volatiles in LEO (with its orbit suitably stabilized to not decay) would be a huge boon to anything coming and going from there.

Personally, I can't wait until they wrangle some metallic asteroids over to LEO, start cutting them up, and deorbiting the chunks -- small enough pieces that they're safe to land without a heat shield and without causing a crater.  Timed correctly to land in safe locations (desert, shallow sea?), of course.  It'll be a long time before PGM prices drop -- they'll be making their cool billions to pay back the investors first -- but I would love to see the day when I can pick up an iridium pipe from McMaster for just a couple grand.

Tim

[apis]

a ion thruster is like 70% efficient so it can counter act the pull. It could be powered by a nuclear reactor at first but I think you can make CNT solar panels and batteries? to eventually make it powered by solar electricity alone. then it would just keep reeling in stuff to build the orbital string.

Ion thrusters in operational use have an input power need of 1–7 kW, exhaust velocity 20–50 km/s, thrust 25–250 millinewtons and efficiency 65–80%[3][4] though experimental versions have achieved 100kW, 5N

5N can lift about 0.5 kg (at 100km altitude), your combined engine and energy source would have to have less mass than that to generate any excess thrust.

[apis]

NEO asteroids are less dV than the Moon (AFAIK).  A source of volatiles in LEO (with its orbit suitably stabilized to not decay) would be a huge boon to anything coming and going from there.

Personally, I can't wait until they wrangle some metallic asteroids over to LEO, start cutting them up, and deorbiting the chunks -- small enough pieces that they're safe to land without a heat shield and without causing a crater.  Timed correctly to land in safe locations (desert, shallow sea?), of course.  It'll be a long time before PGM prices drop -- they'll be making their cool billions to pay back the investors first -- but I would love to see the day when I can pick up an iridium pipe from McMaster for just a couple grand.

Tim

Are you saying a space station in LEO with a bit of spin gravity makes more sense for commercial space mining? But that isn't nearly as fun as a moon city.

I.e. it won't generate any buzz and it doesn't really have the same potential as a moon base for scientific purposes, etc.

[coppercone2]

if you put a nuclear reactor or tons of solar panels up there you can make a grid of thrusters. I am wondering what something reasonably useful to humanity would look like with that model to see if its ridiculous or not. Maybe you can attach some ion thruster fuel to scrape off the rope too.

what would it look like to get a orbital ring going within 20 years using that method? assuming you can muster the production.

if you have the mass of the ring you can get a feedrate requirement that would bring you the amount of material you need within 20 years.

if its a 10000 ton project, you can do it with 500 tons a year. Thats hauling 1.5 tons of rope in a day. that would basically double earths orbital mass emissions.

now you just need rope specs?

if you have 5N/100kW, what does the rest of the math look like? what would be the steady state power requirement to haul 1.5 tons of rope with thrust going for 1N/20kW?

How preposterous is it? how does this math work, since the gravity field is less, do you do distance along a field gradient integral then find a 1.5ton/24 hour power consumption with 70% efficency?

can you calculate some kind of apparent weight as a point, then figure out the distance, then get power?

i don't understand orbital mechanics at all. It would weigh 1.5 tons of earth, so something like 15000N?

am I getting this right, it would be 15000N over 100kM or 13million joules/day or 1500W average?

thats not very much.

[cdev]

Definitely this is true, especially in Western Mediterranean/Western Europe- However, if I was trying to make the same point I would use different dates..  I am probably making some mistakes below and definitely leaving out a number of important other civilizations too elsewhere that also deserve mention..
Someday we'll have a much better picture, especially now with the huge advances people are making in technologies like synthetic aperture radar, photogrammetry and 3D reconstruction which is yielding a lot of information about what covered the Earth in antiquity that is new!

The romans had sewage systems, running freshwater, multi story apartment buildings, etc. Then it all collapsed (politically), the library of Alexandria was burned and the clergymen took over... It took almost 2000 years before any city was comparable. After that it didn't take so long until people figured out how to build steam engines and flying machines. Imagine if the romans would have kept going. What's holding humanity back is mostly politics and human stupidity, not physics.

I agree with the general thought you're trying to express here but I don't think the Western Roman Empire had it in them to get off their asses because of the continued existence of slavery, which was why the Sack of Rome was successful. The lure of coercive labor is very powerful corrupting influence which undermines innovation. And now we are very much falling into a very similar trap, with so called "Mode Four" (which is based on the Middle Eastern 'kafala' system) a stealthy shift which we all need to be aware of is happening to have any hope to prevent it! In short, we need to stand up for the rights of workers to be treated equally and paid equally when they are in the same country especially, and prevent the race to the bottom in all things which is occurring, turning it into a race to the top again, somehow.

Also, the sciences, math, and human civilization existed before the Roman Empire in a great many places, contemporaneously with it and afterward. Also, in Western Mediterranean there was a similar long period of reversal between the fall of the Minoan Crete civilization after the explosion of the Theran volcano (Santorini) in approximately 1600 BC and the rise of the Greek city state around a thousand years later. So really in the West there were two millennium long reversions of civilization each totaling around a thousand years.

Cities in China at the time of Marco Polo rivaled anything else that had ever been seen in the world by a European. The population of China was also larger than that of the US today more than a thousand years ago.

Also, when Cortez arrived in the valley of Mexico he described the Aztec city there (underneath present day Mexico City which is still the largest city in the Western Hemisphere, I think)

Anyway the Aztec civilization he found there was described as incredibly rich and complex and was I think described in the historical record as the equal of any in Europe at the time.

Contrary to what many believe the sum total of New World, pre-columbian, non-Christian technology was quite substantial and left a very large mark on the world which largely has not been acknowledged. In addition to a wealth of domesticated plants which totally changed the way humans lived in the rest of the world, (making possible a substantial increase in human numbers in areas which previously had not supported them) they also had agricultural technology which revolutionized agriculture. the Aztecs for example, used woven mats covered with soil upon which they planted crops in great variety) that seem to have produced more yield per unit of space than anything we do now except for hydroponic gardening which is based on it. Plus it was sustainable, not requiring any inputs which were not renewable. Of course the whole system fell apart very rapidly after the arrival of the conquistadors and much of its legacy was destroyed before anybody thought to try to save it. The first Americans also gave the world potatoes, maize, and made agriculture aware of the need to rotate crops (nitrogen fixing)

I want to mention here the legacy of Native Americans view of the world and where they fit into it, as steweards of the Earth, obligated to not take any more from it than they needed and incredibly attuned to the world around them in a great many ways which we live ignorant of today) Also their version of democracy (superior to the Greek version in every respect) and throw out that if we are to leave Earth and travel to the stars, we should strive to transform our society to be much more part of Nature, and living in harmony with other living things and in stewardship of the planet rather than obsessed with 'dominating' Nature. This is an absolutely crucial change I suspect we will not survive long in space without making. A number of posters in this thread have expressed sentiments along the lines that if we don't treat our planet and the rest of all of us well, we wont be successful in space either, or don't deserve to control other planets - where we may meet embryonic societies of intelligent life at earlier stages than our own, just as this may have happened to us in the past.  (and soon 'we' will also include our intelligent machines, who-if we don't make the mistake of reverting back to the worst kinds of coercive societies, may I hope become our friends as well as our 'children'.)

At that point the 'need' in economic terms for humanity to be hierarchical and 'work' will have long passed however, work will most certainly continue and be transformational and I suspect far more productive than today, freed as it may be of a lot of very destructive baggage.

So, I think we should think long and hard what we want the long term goals of humanity to be, what is the path which will bring out the best in people. As its our choice. We especially need to prevent the urge to try to lock the planet or nations into anything as we are seeing.

Honesty is the road forward, dishonesty the road back. And we could learn a lot from the first Americans about democracy and living in harmony with the planet and the other creatures that we share it with too.

We probably would have learned much more had Spain not been in the midst of its centuries-long Inquisition, and the UK and the rest of Europe in the grip of a inbred incestuous group of rigid monarchies that had endless wars with one another over what amounted to family quarrels and ruthlessly eliminated any talent it could not control.

So I think your main point totally right, as far as so called Western Civilization goes, the periods of time when it has not been deliberately handicapped - when there have not been these huge barriers to progress indeed have been short.

[coppercone2]

can someone check that bootleg calculation of mine? it does not feel right for some reason. only 1500Watts?

the problem I think is that the orbital velocity is 7km/s. not sustainable for even the best boeing product

at geostationary orbit it would be 1500W still? since most of it is in space?

[In Vacuo Veritas]

Physics isn't the bottleneck that is preventing us from undertaking big projects, like replacing fossil fuels.

Right. That's why we're already on the Moon and flying supersonic across the Pacific daily.

Look, if you can't see limits and understand where they come from, you are arguing like an 8 year old who still believes in Santa Claus.

There are limits. They are real. They don't care about you or your bizarre beliefs. Whether they be biological, physical, chemical, or material. Limits.

And if I had said twelve or eight years you would have been just as upset.

The point is, you space cadets are all hot air. There will be absolutely none of your grandiose fantasies happening. Ever.

The End. I don't know why you cling to these bizarre space cultist notions. But it's a disease I see a lot with huge nerds. Nothing new. I first started noticing this rabid, blind, fact-free raving about space about ten years ago, and it hasn't stopped entertaining me since!

 

[In Vacuo Veritas]

https://en.wikipedia.org/wiki/The_Millennial_Project

Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space!

Yeah! It's politics holding us back from Space! Space! Space! Space! Space! Space!  Although Apollo was 100% political! Your precious free market would NEVER have sent a single bolt into Space! Space! Space! Space! Space! Space! without the government!

We need air? Space! Space! Space! Space! Space! Space! Space! Space! Space!
We need food? Space! Space! Space! Space! Space! Space! Space! Space! Space! Space!
We need gravity? Space! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space!
Will it hurt? Of course not! Space! Space! Space! Space! Space! Space! Space! Space! Space! Space!

Gotta get into Space! Space! Space! Space! Space! Space! Space!

We ain't traveling or exploring anything here! We want to go into Space! Space! Space! Space! Space! Space! Space! Space!

Because it's just like Star Trek! I assume I'll sit in a large comfortable ship with artificial gravity and impossible materials, sorry, densified neutronium (all very possible, just like a skyhook, a simple engineering problem that somehow hasn't been solved yet but don't worry: a bunch of nerds with computers will fix it)

Space! Space! Space! Space! Space! Space! Space! Space!

Who needs water? Who needs the ground? Space! Space! Space! Space! Space! Space!

Asteroids! Helium 3! Fusion reactors in my backyard ... on Mars!

Space! Space! Space! Space! Space!

Hurrah!



Space!

[Mr. Scram]

Who said anything about ten years? You keep making up straw men, and not very good ones either.

You know, not too long ago you there wouldn't have been a McMaster-Car where you could buy anything. Things have to be invented and then designed and then built. Ten years ago you would have said the same thing about reusable rockets, can you buy those at McMaster-Car? It's obvious you don't understand how the world works or basic physics. There's a lot of ongoing research being done on tether systems.
Reading comprehension isn't your strong suit either obviously. Physics isn't the bottleneck that is preventing us from undertaking big projects, like replacing fossil fuels. But I'm sure you think that's impossible as well. If it was up to you we would still be using stone tools and fire would be considered untameable.

Don't feed the troll. Some people are just on these forums to pick fights to entertain themselves. Luckily it's rather obvious.

[In Vacuo Veritas]

Who said anything about ten years? You keep making up straw men, and not very good ones either.

You know, not too long ago you there wouldn't have been a McMaster-Car where you could buy anything. Things have to be invented and then designed and then built. Ten years ago you would have said the same thing about reusable rockets, can you buy those at McMaster-Car? It's obvious you don't understand how the world works or basic physics. There's a lot of ongoing research being done on tether systems.
Reading comprehension isn't your strong suit either obviously. Physics isn't the bottleneck that is preventing us from undertaking big projects, like replacing fossil fuels. But I'm sure you think that's impossible as well. If it was up to you we would still be using stone tools and fire would be considered untameable.

Don't feed the troll. Some people are just on these forums to pick fights to entertain themselves.

No no, you've convinced me with the weight of your arguments. All very plausible. I don't know how come I never saw it before.

Clearly, the species, all 7.5 billion of us belong in space. It's a mistake to live on a planet.

SPAAAAAAAAAAAAAAAAAAAAAAAACE!!!!!!

Let's go! Pack your shit! Nah forget it, we'll just 3D print what we need on the way!

The way where!??

SPAAACE!!!

 

You guys are clowns.

[T3sl4co1l]

Are you saying a space station in LEO with a bit of spin gravity makes more sense for commercial space mining? But that isn't nearly as fun as a moon city.

I.e. it won't generate any buzz and it doesn't really have the same potential as a moon base for scientific purposes, etc.

It doesn't need to create buzz.  It will create money.

Money has a way of creating buzz all by itself.

Tim

[coppercone2]

Are you saying a space station in LEO with a bit of spin gravity makes more sense for commercial space mining? But that isn't nearly as fun as a moon city.

I.e. it won't generate any buzz and it doesn't really have the same potential as a moon base for scientific purposes, etc.

It doesn't need to create buzz.  It will create money.

Money has a way of creating buzz all by itself.

Tim

you still need to attract investors.