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Diamond Nanothreads Could Support Space Elevator (space.com)
Taco Cowboy writes with news that Penn State researchers have discovered a way to produce ultra-thin diamond nanothreads that could be ideal for a space elevator. According to the report at Space.com, The team, led by chemistry professor John Badding, applied alternating cycles of pressure to isolated, liquid-state benzene molecules and were amazed to find that rings of carbon atoms assembled into neat and orderly chains. While they were expecting the benzene molecules to react in a disorganized way, they instead created a neat thread 20,000 times smaller than a strand of human hair but perhaps the strongest material ever made. ... Just recently, a team from the Queensland University of Technology in Australia modeled the diamond nanothreads using large-scale molecular dynamics simulations and concluded that the material is far more versatile than previously thought and has great promise for aerospace properties.
Will it last forever?
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
In The Fountains of Paradise, Arthur. C. Clarke wrote about the use of a diamond filament for building the space elevator. The main character, Dr. Morgan, carried around with him a retractable rope made of this filament. He uses it at one point to climb down a cliff face, and it's so thin it can be barely seen...
Kudos, Arthur...
And The Foundations of Paradise, Arthur. C. Clarke.
How exactly does a space elevator "save" energy for lifting loads to orbit?
The same way using a ladder saves energy over using a jetpack.
systemd is Roko's Basilisk.
The person you heard that from was wrong.
In a rocket,:
- Rockets are quite inefficient, about 16% energy efficient to reach orbit.
- You have to lift your propellant, only to throw it all away
- The rocket not only has to do work against gravitational potential, it also has to provide lateral kinetic energy to reach orbit. The kinetic energy component is huge.
For a space elevator:
- The lifting motors are highly efficient, you just have to keep the power beaming losses reasonable.
- You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.
It sounds wonderful, but I have two questions before I book a ride...
How many cubic kilometres of material are needed to build the space elevator?
Will it turn into a pile of dust if it's hit by lightning?
USB, USB, USB!
They are not even close to sufficient in weight bearing capacity for an earth space elevator. Nothing we have is within 3 orders of magnitude of being sufficient. Not even in the smallest testable quantities. Now, we can build a space elevator on the moon. But not from earth.
Clarke's science > Robinson's science.
For a large factor of >.
Super strong, super thin threads? Wasn't there a scene in Neuromancer where one of those, extended from a diamond spool worn as a thumb, constituted a deadly weapon?
At some point in time also a spider silk was the strongest material - stronger than steel. But I have yet to see a crane that uses spider silk to lift containers.
Wake me up when we can create a 1km long and 1cm thick rope from these diamond nanothreads.
Your post is simply incorrect.
1) Rockets are not "quite inefficient". Their Carnot efficiency is usually 80%, net propulsive efficiency around 70% - way better than a gasoline engine (~35%) or diesel engine (40-45%). What they suffer from is totally different: the rocket equation. This mandates exponentially increasing fuel needs to reach a given delta-V, with the exponent proportional to the ISP. But fuel costs have nothing to do with how expensive today's rockets are, we're nowhere near that limit. The Space Shuttle consumed about $2m of propellant to deliver 25 tonnes to LEO, or $80/kg. Using electricity at 100% efficiency and $0,80/kWh it would cost about $0,80/kg to reach orbit. Today's launch costs are about $5k-10k/kg for large launches (the Shuttle was said to be about $18k). So you can see that the fuel costs are just the tiniest fraction, and that it's the engineering challenges of cost-effective production and reuse that are the issue.
2) The "keeping power beaming losses reasonable" is the problem the parent was describing. There is no known way to efficiently transfer power to a small object over tens of thousands of kilometers. Direct transmission isn't even close with conventional conductors, a superconducting line would be many orders of magnitude too heavy, and the cable itself would not be a superconductor, and even if it were its cross section would be way too low. Batteries don't cut it in terms of energy density. And the requirements that climbers be very light precludes nuclear except for the most unrealistically-massive of space elevators. To make RF power beaming remotely efficient over such distances requires a receiving antenna taking up dozens of square kilometers. Laser power beaming means receiving end (solar cell) losses (which even if the solar cells are tuned to a particular frequency you're unlikely to do better than maybe 30-40%) and laser losses (high power lasers are generally in the ballpark of 0,1% efficient; diode lasers can reach up to 25% or so but have far too poor beam quality and are way too weak to be practical). And of course you need a frequency that minimizes atmospheric losses at that.
Perhaps some day power transmission over those distances might become practical, but today it isn't.
This is just the very start of the problems with space elevators, of course. I know space elevators make great books, but they're not practical in the real world. Look into actively suspended structures for your "direct climb to space" needs. They're buildable with today's materials and can get greater than 50% efficiency in energy transfer.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.
Any cargo climbing to the upper floor would need to gain a proper orbital velocity. It might get it from the ground or from the upper floor or from its own engine. It means that you would need to provide some fraction of the lateral kinetic energy by accelerating laterally either the cargo or the upper floor.
That's the reason that the first thing you'd do with a working space elevator, is to build another space elevator right next to it.
You don't need to lug several times your payload's weight into orbit as fuel.
The downward trip can actually generate electricity.
Also, the fuel can be whatever you want. A lot of these fuels are a lot cheaper than disposable tanks of rocket fuel.
Space elevator can actually produce its own electricity (and a lot of surplus) from Earth's magnetic field, so the energy requirements are essentially null.
The problem is that any "crawler"/"lift" would be limited to maybe 300km/h speeds optimistically, and as result take a month to reach GEO. And due to tensile strength limitations, only one payload at a time could travel. So while yes, that would be extremely cheap in terms of $/ton to orbit, the throughput, tons/month to orbit would be extremely limited.
What is our current throughput? If you only count the cargo and not the rockets, I doubt all launches combined even average a single ton per month and at considerably higher cost per pound. I don't see this as a limiting factor as it's a lot better than we currently have. If it becomes a limiting factor then that means that it is constantly full and bringing in plenty of money so we need to just build a second or third one.
The bigger problem I see is the threat of damage and/or sabotage. Ideally you would have a system that could self-repair if it broke or at least safely descend and have a way to quickly be repaired and redeployed. If you had lightweight 1km segments that if disconnected could retract and safely float down that might be ideal. Even if you needed to use a rocket/shuttle to launch all the segments back to orbit and then lower them again with the space hook, this would be considerably cheaper than having to rebuild it from scratch if something happened to it. Not to mention the danger of a huge cable circling the globe.
It will still be 50 years before it is built as everyone still laughs at it.
You don't need energy in the elevator. Simply have two elevators and a pulley wheel at the top. Lifting something then is just a matter of capturing some space junk or asteroid of suitable mass and lowering it in the other elevator.
No, I mean $18k. From your link:
The $60k is when you include the cost of the whole program (including the design/development phase) which no figure in my post included. If you want to compare, you need to compare equivalent situations: the incremental cost per launch. And the incremental cost per launch of the Shuttle was an estimated $18k/kg.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
The dude who created Molecule Chain was named Sinclair!
You would use solar as your primary means of propulsion, and probably a secondary system for use inside the atmosphere. Current solar cells would be good enough to get you up to say 100km/h with reasonable load. At that speed it would take a couple of weeks to reach the top of the elevator, or less if you just wanted to get into LEO. Speed isn't that important when hauling cargo though. The array would be fairly large, like ISS large, but outside the atmosphere that isn't a problem.
Inside the atmosphere you could beam power from the ground. It would still need advances on microwave beaming technology, but not unreasonable ones.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Come back when you've made 2 metres....
Stuart http://stuarthalliday.com/
Excellent.
Stuart http://stuarthalliday.com/
There have been 69 successful launches this year:
https://en.m.wikipedia.org/wik...
Which doesn't mean anything without a payload capacity. Many of those launches appear to be cubesats and other small payload launches. That being said, I did find that the ISS resupplies are about 2 ton so if the space elevator really did only have an equivalent fixed 2 ton capacity and a fixed 30 day roundtrip then it would be the equivalent of only 12 ISS resupply trips. Hopefully we could over time increase the number(frequency) of cars, the capacity of the cars, and the speed of the cars.
Calculate the mass of your cable. It doesn't work.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
And The Foundations of Paradise, Arthur. C. Clarke.
I think you meant Fountains of Paradise. Another sci-fi great, famous for his three laws of robotics, did write something called the Foundation trilogy. A space fountain appears to be different from a space elevator, but I'm no expert on the distinctions between these and other combustion-free space launch concepts like the skyhook or orbital ring.
Solar cells may produce - on a clear day - 200W/m^2, if they're sun-tracking and unshadowed. A climber climbing over the course of two weeks (more on that in just a second, you need to climb far faster) has to climb 35,5 meters per second. A small 1 tonne climber with 2 tonnes of cargo requires 1 megawatt of power, meaning 5000 square meters. Think you can fit 5000 square meters of sun-tracking solar cells on a climber that only weighs one tonne?
Speed is important because it defines throughput, and your cables - even if you have some mythical unobtanium 100-120 Gpa diamond filament tether - are still very massive objects with very tiny objects climbing them, meaning you need high throughput to make them economically justifiable.
I don't think most people discussing space elevators realize how tiny the margins on these things have to be even with a cable made of unobtanium. Inside the atmosphere is irrelevant. It's the tiniest fraction of your 43000 kilometer trip, you have no margin to make a special case for in-atmosphere propulsion. It's only relevant for the additional problems it causes your cable, such as wind, lightning, ice, oxidation, etc.
Space elevators really aren't a good design. They're just totally impractical even when made of unobtanium. But science fiction has locked a generation onto this concept when there are far better concepts available.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
No space elevator designs that are even vaguely plausible include a moving cable. To understand why, consider the mass of such a cable: the energy required to accelerate it and then decelerate it for the cars to start and stop would be phenomenal. You could potentially have a loop that would continuously move in a circle, but you'd still have problems starting it. Just dropping things from the top wouldn't be enough, because you'd need to get them a fair way down before they'd stop orbiting and actually provide force in the correct direction. I don't even want to think about the lateral forces that such a structure would have to endure.
I am TheRaven on Soylent News
Annoyingly, in a post I typed previous to this one, I put Fountains... bloody fingers.
1MW for a 3000kg climber? That seems rather pessimistic. I was using 2.4MW to lift a 20,000kg climber. That's achievable with multiple pulsed lasers and AlGaAs photovoltaic cells covering a reasonable area. You could expect 60% efficiency at that level, hitting about 55W/cm2 or more. Remember that PV efficiency goes up as the light gets brighter, and I think that there are actually better types of PV now anyway.
You would start off with a ground based laser, and then move to in-orbit lasers as you get higher up.
Economically the construction cost will be huge, but once you have one you can build more relatively cheaply because it costs very little to get mass into orbit. You could also do a lot of other projects, like massive in-orbit solar arrays that beam power back to earth via microwave link, or building very large space stations etc. so you might be able to amortize the cost. You have to think of the new things you could do, not just assume competition with existing satellite launch systems.
Speed isn't a huge problem if your cable can support multiple climbers. The cable is the difficult part, power transfer is solvable with current technology.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
It's a lot more fundamental than that. Even with 120 GPa unobtanium they still can't support themselves over those sorts of distances - any cable has to have a large taper factor (the lower the breaking strength, the larger the taper factor is needed). Which makes moving cables impossible, because as soon as you rotate it, the taper is structured all wrong - it has to constantly be thickest at the top and thinnest at the bottom or it will break.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
You want to talk joules(energy), not watts. And the energy requirement is ~33MJ/kg
Let's see...a month at 300km/hr takes you 216000 km. Do you really think GEO is almost as far away as the moon? Or are you just arithmetically challenged?
Hint: at 300 km/hr, GEO is about five days away....
"I do not agree with what you say, but I will defend to the death your right to say it"
The summary links to a lousy article that says essentially nothing about the actual research. Here is an account that describes the material under study.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
You mean like how a bed of nails causes all the nails to penetrate extra deeply? How snowshoes cause the feet to sink extra deep in the snow?
Just...no.
Excellent point. Also: the technique of weaving fibers into a mesh that does not pull apart (essential for soft ballistic protection) is well developed.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Yes, space elevators could become the Foundation of a space utopia, if we can only get them off the ground.
Nah. No desire to revisit that Communist propaganda. Might as well have been published in The Worker.
Neat engineering concepts, but his sociological stuff in there was nauseating.
Wrong again. There's gravity everywhere, including GEO. There's no effective gravity in any orbit because the gravitational force is counteracted by your motion caused by inertia: you're in constant freefall when you're in a stable orbit, so it appears to be zero-g in your reference frame, even though it really isn't.
But there is gravity in GEO, and theoretically to the ends of the universe, all caused by Earth's mass: just look at the gravitational equation, there's no distance limits on it. Of course, the effect of gravity diminishes with distance and it competes with the gravity caused by other bodies so past a certain point it becomes negligible. But for a practical example, the Moon exerts significant gravitational force on the Earth, which is what causes our tides, and the Moon is much farther away than GEO.
You wouldn't know communism if you were planting potatoes in a collective.
I think that a space elevator is entirely impractical for a planet with an atmosphere (and air traffic); aside from the material science challenges, there is just too high a risk of one errant aircraft or piece of orbital junk taking the whole thing down.
The Lofstrom loop cited by the parent poster is interesting, but seems to suffer from some of the same material science and fragility issues. Its energy consumption when idle is also an enormous cost factor (the power required to overcome atmospheric drag would be staggering all by itself). From a practical standpoint, I cannot imagine any organization building either one of these on Earth; the costs and risk are too formidable.
For practical space launches, the best alternative would appear to be a hybrid air/space approach similar to Scaled Composites' SpaceShip One (also used by Orbital Sciences' Pegasus satellite launch system). Your first stage is essentially a cargo aircraft, which gets your space vehicle up past the first 10 KM of altitude and the first 600 KPH of velocity without the massive inefficiency of a first-stage rocket booster. The winged second stage is either a pure rocket vehicle or a hybrid air-breathing / rocket vehicle. This system uses atmospheric lift and rocket power where each is most effective; the big airfoils and air-breathing jet turbines stay in-atmosphere for immediate reuse (this is much more cost-effective in the long term than a reusable first-stage rocket booster, as it can be reused literally thousands of times between major overhauls).
IMO, this is what the future of space launch will look like.
"My strength is as the strength of ten men, for I am wired to the eyeballs on espresso."
I hope everyone notes though: energy cost $80/kg, launch cost (at least) $18,000/kg.
Talking about "energy costs" shows rank amateurism when talking about space flight. Virtually the entire cost is the flight hardware and ground support infrastructure. Energy costs aren't even rounding error on those.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
What do you mean "you were using"? Gravitational potential energy at Earth at sea level is 9,81 * ChangeInAltitude * mass. 35,5 m/s * 9,81 * 20000 = 7MJ/s = 7MW. If you "were using" 2,4MW then you were only climbing at 12,2m/s meaning your entire trip takes 41 days - over a month. Which means that your elevator has laughably worthless throughput. And 20k kg climber requires a massive elevator massing millions of tonnes *with* unobtanium. So you're proposing to launch millions of tonnes of unobtanium to GEO in order to send a fraction of 20tonnes up once every 41 days? Good luck with that.
That's exceedingly optimistic even for monochromatic light (which I see we're back to discussing). Have you ever priced the sort of Spectrolab cells you're proposing here? And anyway the highest monochromatic conversion rate ever recorded - lab scale - was 53%.
Only when you can keep the cells cooled to the same ambient temperature (and it's only a relatively small gain). How exactly do you propose to ditch megawatts of waste heat up there? Heat is a killer to solar cell efficiency. And several megawatts shining on a relatively small area is otherwise known as "vaporizing it".
No comments about the 0,1%-ish efficiency of the sorts of lasers that actually have the coherency and power to beam over such distances, I see. Even over the distances of your "in-orbit" lasers, of which apparently you want there to be hundreds of thousands if you want to ensure that there's one close to the tower at all altitudes at all points in time. Hundreds of thousands of multi-megawatt lasers each consuming a gigawatt or so of power. In order to launch a fraction of 20 tonnes to GEO once every 41 days. Great strategy.
There is nothing "cheap" about what you're proposing. Your capital costs are nonsensically high, and you have to pay interest on capital costs if you want to live in the real world, and interest accrues interest. You will never, ever reach an economically valid argument for it. And for what gain? If you're turning $0,08/kWh industrial-rate grid electricity into climbing power at 0,05% efficiency then you're paying $160/kg to get to orbit, several times the price to orbit of what's possible with a rocket if it can be made reusable with minimal turnaround costs between flights (as mentioned earlier, the Shuttle's propellant cost to orbit was only $80/kg, most of that in the SRBs, which aren't the cheapest of propellants). And of course it's not even close to a Lofstrom loop, which can be made without unobtanium and deliver payloads at an energy cost to orbit of about $1,60/kg, with present tech.
So you want to make your cable even bigger, heavier, and more expensive. How many times more expensive do you want to make it? 5 times? 10 times? 100 times? Why not just say that your cable is going to be the mass of the moon's worth of unobtanium while you're at it?
And again, we're only talking about the most basic of problems with space elevators here, let alone actually getting into the countless engineering problems, some of which have no known solutions, and none of which you really have a mass safety margin to properly address. The resonance issues are some of my favorite ones: from the climbers, from the atmosphere, from the sun and from the moon. You have a giant cable which has basically zero ability to damp itself, and no mass leeway to install any sort of damping system of the sort
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
And you plan to propose a rotating cable that somehow maintains its original taper as it rotates how, exactly? As soon as you start rotating it, the thick part will begin moving downward and the thin part upwards. At the bottom of its rotation it's precisely the inverse of what you need.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
Wow, it's almost as if my original post didn't read:
The "rank amateurism" here is in your reading comprehension.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
There's 'a lot of very serious engineering concerns' when building bridges and skyscrapers, too. What's your point?
Nobody is looking for a 'magic material', any more than *steel* was a 'magic material' when it came to building bridges across the Mississippi. We already know the properties needed, and even have some viable candidates where we need to figure out how to mass produce long fibers.
Sure, but now you're proposing a ladder that masses a billion times or more than the house, needs materials that theoretically may not even exist, requires co-operation at a planetary level that has never happened before, has been talked about for half a century and you don't even have even a single shred of a ladder yet.
Compared to that, jet packs exist, they are manufacturable, don't require magical materials, and they have been around for half a century rather than talked about.
So painting a house with a jet pack makes orders of magnitude more sense than your disingenuous comparison to a ladder.
because the potential energy of an object coming down can be used to raise the potential energy of an object going up...
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
This is the longest "Oh yeah? Yo momma stinks!" post I have ever read.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
But what if the elevator carried some extra mass and shot it out sideways as it went up, to take advantage of the slingshot effect?
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Would diamond/carbon nanofibers be sufficient for a mars or lunar space elevator?
People claim all sorts of things. While there are lots of problems with a space elevator on a world as large as Earth, energy efficiency isn't one of them.
Personally, I doubt that a space elevator will ever be practical on Earth, but it should be on Mars, and it definitely would be on the Moon. For Earth I'd favor something like the pinwheel. You can think of the pinwheel as a rotating space elevator that doesn't reach as far down as the ground. (You'd probably want to not reach further down than the upper stratosphere to minimize frictional losses.) You fly up to meet the descending arm at the bottom, and unload cargo onto it. Descending cargo can be handled the same way, or you could use a combination of parachutes and lifting bodies. You need to balance freight going up and coming down or you get orbital decay...either it lifts too high or comes down too far, but this can be handled by a station keeping ion rocket, possibly of Vasimir design. Reaching a height is a lot cheaper than going into orbit. This does require a large orbital mass.
I think we've pushed this "anyone can grow up to be president" thing too far.
Go lie on an elevated bed of nails.
Then let someone fire a gun at at the nail heads beneath you.
When the material is so thin, instead of it spreading the force out to support your meatflesh, your meatflesh ends up supporting the material (by being sliced and diced). You need to carefully weave these materials in layers or apply some other layer to actually distribute the force before it gets to you. Both options make them heavier, thicker, and less flexible. Making the material thinner and stronger is WORSE for armor.
The difference being that a tether snapping and raining superstrong microscopic diamond fibers 100's of km long in a path across the equator is several orders of magnitude more destructive than a bridge collapsing.
Yes, that's why we don't have steel, because it "isn't in the periodic table"; that's why we've discovered all manner of interesting properties in materials that aren't "in the periodic table" but are derived from combinations of the elements, various crystalline and other molecular arrangements of those structures, both those found in nature and those that have arrived courtesy of, you know, science.
The science takeaway -- as opposed to your "man can never fly" mode of reasoning -- is that this is a materials issue, and not one that carries any impossibilities, either.
Here are some quotes for you to contemplate:
"As far as sinking a ship with a bomb is concerned, you just can't do it."
-- Rear Admiral Clark Woodward, 1939
"The energy produced by the breaking down of the atom is a very poor kind of thing. Anyone who expects a source of power from the transformations of these atoms is talking moonshine."
-- Ernest Rutherford, 1930
"There is not the slightest indication that nuclear energy will be obtainable."
-- Albert Einstein, 1932
"Our inventions are wont to be pretty toys which distract our attention from serious things. We are in great haste to construct a magnetic telegraph from Maine to Texas; but Maine and Texas, it may be, have nothing important to communicate."
-- Henry David Thoreau
"I must confess that my imagination, in spite even of spurring, refuses to see any sort of submarine doing anything but suffocating its crew and foundering at sea."
-- H. G. Wells, 1901
"What can be more palpably absurd than the prospect held out of locomotives travelling twice the speed of stagecoaches?"
-- Quarterly Review, 1825
"Rail travel at high speed is not possible because passengers, unable to breathe, would die of asphyxia." ...you are a proud member of a very famous group of fools. :)
-- Dr. Dionysus Lardner, 1793-1859
I was asked how they would save energy, and that's all my answer covered.
systemd is Roko's Basilisk.
I guess that if you would want the tether to become straight again, you would need to press the STOP button. The thing is, some elevators seem to miss that button for whatever reason.
Yes, you are right, the elevator would swing at most.
The fact that A, B and C which were previously considered to be impossible eventually were made possible does not mean that D which is currently considered impossible will eventually be made possible.
The obvious example is FTL travel/time travel.
Also, the "it's just an engineering problem" misses the point that you can't separate engineering from economics and politics. We know that we could all be flying in supersonic passenger planes now, because we built Concorde. But there are no supersonic passenger planes in service. It was never just about engineering a supersonic passenger plane.
To have a right to do a thing is not at all the same as to be right in doing it
You don't need energy in the elevator. Simply have two elevators and a pulley wheel at the top. Lifting something then is just a matter of capturing some space junk or asteroid of suitable mass and lowering it in the other elevator.
Holy crap you have just invented a perpetual motion machine! That'll show the doubters.
To have a right to do a thing is not at all the same as to be right in doing it
Wells had more than a failure of imagination, he had a failure of knowledge. In 1776, a submarine was used in the American Revolutionary War. https://en.wikipedia.org/wiki/Turtle_(submersible)
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59% .... http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=122385&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D122385
That's the result of a quick search. I have no idea what the practical and theoretical limits are.
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Space elevator and Low Earth Orbit are not a particularly good match. Most of the energy needed to get into low earth orbit is to gain orbital velocity, the elevator is contributing mostly altitude.
Space elevator to LEO would work something like this: Vehicle is lifted on the elevator to about 100 miles, detaches from the cable and then uses rocket motors to boost speed by about 15,000 mph -- all without damaging the cable as the vehicle maneuvers rapidly.
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As the thread gets finer, so does the mesh. Pressure remains constant when thread diameter and mesh spacing change in sync.
The problem is that thin chain mail will not distribute impact well, and thickness achieved with multiple layers helps that.
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I've done real work on solving the FTL problem - about 50/50 solvable. - Solvability ultimately depends on the ability to capture or create then contain negative mass matter. The biggest brake on the whole thing is that general relativity the dominant theory in the field for the last 100 years is complete nonsense above the speed of light. - You can have two of the three - general relativity, black holes, conservation of momentum..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
You add a layer underneath tuned to complement the top layer. For instance in this case designed to help spread the inertia of the bullets kinetic energy across the material. There's a new gel material that apparently does exactly that - shock solidifies it and it momentarily becomes almost as hard as steel..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
I guess a see saw must be one as well then, I'd better patent that.
If you think someone isn't free to have a different definition of "freedom" you may be a tyrant.
While I've definitely liked some of KSR's work, Red Mars was tedious enough to put me off the rest of that Cycle. I'll not cross him (or is it a she - I can't remember, and can't be bothered to look it up) off my reading list. But the Mars cycle isn't going to get me at the bookshop again.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
... yet conceptualized? Or how it could be built - given that materials become viable and available?
Self-importance and self-indulgence is the root of ALL evil.
Let's see. First quote: that's from well after US tests bombing and sinking several obsolete warships, including ex-German battleship Ostfriesland, and at least a decade and a half after most admirals considered carriers of importance only second to battleships (and many not with the qualification), You picked an idiot saying something stupid, that most admirals of the time would disagree with.
Einstein's comment may have been dead on in 1932, for all I know. That changed fairly rapidly.
So, what you're saying is that you can cherry-pick really stupid quotations from history. (You missed Admiral Leahy, in roughly the same position as the chairman of the JCS today) insisting in 1945 that a nuclear bomb was impossible, and pointing out he was an explosives expert.)
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
I don't see how general relativity could possibly give nonsensical answers to questions involving objects traveling over the speed of light, since (a) it isn't intended to work with FTL, and (b) nobody knows what FTL would be like if it were possible, so it's difficult to say that predictions would be nonsense.
You seem to assume that we can have matter of negative mass. The fact that we could do neat things with it doesn't mean it can possibly exist.
What does general relativity say about black holes and the conservation of momentum? Black holes have momentum, and it seems to me that some theoretician would have mentioned this in a peer-reviewed journal if it were true.
BTW, if you have special relativity and FTL, you've got time travel.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
Seriously. This will be the first published use of the material.
Hi. The real problem with both general and special relativity is that they both rely on the idea of time as dimension, which is generally incompatible with most FTL models. In my version time does not behave as a dimension at FTL speeds, instead time is point like giving a 3 Dimensional space time - so time travel is impossible. (In the FTL model 4D space time still exists at quantum scales, but becomes non-coherent at the quantum limit.)
There is certainly no hard proof for this version of the FTL but equally there is absolutely zero hard proof for the standard 4D space time version.. There are several pieces of indirect evidence for my FTL model, plus the FTL model unifies (a very slightly modified) general relativity with quantum mechanics and with classical physics, plus the FTL model is also at least an order of magnitude simpler than the standard relativistic model. The big negative for the FTL model is that its maths is non-continuous, and ‘ugly’, and has to map a number of infinite quantities. (I made the first step into the FTL while working on the maths of Strong AI on infinite non-finite sets and self-complete systems..)
I have recently found a real experiment that just might be able to test the two models against each other. - The FTL model predicts that black holes should have a central massive singularity, while general relativity predicts that a black holes mass should be distributed.. This difference is theoretically detectable in the behaviour of objects in close orbit around black holes.
As for negative mass matter, obviously again there is no proof on whether it exists or not. However if my model is correct then negative mass matter is a pretty good candidate for dark matter. The basic predicted behaviour of negative mass matter is that it is tachyonic (FTL coherent) and so it shouldn't interact with ordinary matter - except through gravity. In this model tachyons can also travel slower than light because their internal geometry remains FTL coherent at all STL speeds..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..