Human Technology: Year 2154

[auroraglacialis]

Originally Posted by Human No More

It's a system of homeostasis as when a balance is changed, a new equilibrium occurs somewhere barring extreme rapid changes - the question is what the limits of it are, and that's why Earth in Avatar is the way it is.

Earth is not like that really. Climate fluctuates quite rapidly due to a couple of feedback loops. Anthropogenic climate change pushes this even faster and to greater limits (if there are any). At the same time, civilized humans diminish the resilience and flexibility of ecosystems, meaning they are not able to return to former states and they may not be able to adapt themselves to new states.
It is possible that there is a state that is a tropical/desert Earth and that is stable, we may see that.

Originally Posted by Advent

Well, here's to hoping Humanity can get things done. And, if not, I've got a feeling nature's got a trick up her sleeve to clean things up. Us included.

This is what bothers me about hope. It is a bit like going to Las Vegas and hoping not to loose money. There is a bit of fatalism in hope as in "we can only hope". Climate change and ecosystem collapse as well as water scarcity may quite well be Earths way to correct the problems - "us included"...

Originally Posted by Banefull

That carbon dioxide/methane/other greenhouse gases in the atmosphere will stay up there for a while. The effect compounds over time and it will come to bite us in the somewhat distant future unfortunately .

... or not so distant. I will not be around at the end of the century, but those who will, may see a climate that is 5°C (not °F) warmer than today. That would mean vast landscapes that are uninhabitable...

Originally Posted by Human No More

there are no robots. The manufacturing is done through processes that exist in concept today such as stereolithography.

Yes, one can with that technology work with relatively little material, but the initial investment still has to be quite something. At least the parts to build the first of these machines and the machines that assemble the new machines from the parts and enough raw materials to produce them until one has at least enough mining equipment to do iron or aluminum mining and smeltering to get new raw materials. These big mining trucks and the houses and fences are not made from carbon fibres or plastics.

Why not? The point is that the vast majority of the sea is used for algae production - that is, with the right infrastructure, easy and cheap to do so, particularly if the land becomes unsuitable for agriculture.

It may be possible in theory, but the investment is large - after all you'd have to basically create some kind of barges or cages on a huge scale, probably larger scale than land based agriculture. One would need fertilizers and equivalents of pesticides and herbicides as well. I do not even want to think about what the oceans would look like in such a world - without land plants, the soil gets washed into the oceans, pollutants get into the sea and there most likely would be a problem with oxygen supply. Climate would collapse totally. No, an Earth without land plants certainly could survive with intact marine ecosystems, but with an oceanwide monoculture - in such a short timeframe... I do not think this would really work out.

Also, the switch to an ocean based agriculture replacement would take immense investments and planning. This cannot be done in a couple of years and it needs a lot of work and energy and resources. It certainly is even harder to do with a bad economy that is in recession, rising population and resources like land based food and energy getting scarcer.

Even a small reduction of food output in the past years by comparably minute amounts supported recessions and took part in inciting revolutions in Africa. A reduction by 10% would certainly cause widespread civil and military unrest and economic trouble which would make it very very hard to globally switch to new energy or food production systems.

14.26m/s^2, so yes. Of course, most of the ISV has no gravity anyway, just two centrifuges which house crew modules.

I'd assume that to travel that distance, they'd have to accel at 1g gravity for the whole travel time (halfway to accel, halfway to decel), so the centrifuges would only be needed in orbit. I calculated this online, and it seems like it is plausible indeed to travel the couple of light years at a constant acceleration of 1G in the timespan provided (6 years), if that calculator tool is programmed right . It still seems like quite a challenge to keep 1G up and running for all that time. -> How to Get to Alpha Centauri | Space.com

There is a shield that is intended to protect against any dust that can theoretically be encountered

Ok, How would these shields work? Are they SciFi inventions or somehow plausible? I can imagine anything like this would either take quite some material or quite some energy use. Something that can even bother a particle of dust that is travelling at 0.7c must be quite impressive.

Space is quite empty, but I am not sure how much we know yet of the chance of dust particles hitting. At least in the vicinity of the solar system, there seems to be quite a few of them...

[Human No More]

Originally Posted by auroraglacialis

Earth is not like that really. Climate fluctuates quite rapidly due to a couple of feedback loops. Anthropogenic climate change pushes this even faster and to greater limits (if there are any). At the same time, civilized humans diminish the resilience and flexibility of ecosystems, meaning they are not able to return to former states and they may not be able to adapt themselves to new states.

That's the definition of homeostasis - it fluctuates above and below a certain level. Of course, human activity changes the equilibrium level, but if it is within the capacity of the ecosystem then not so much changes.

... or not so distant. I will not be around at the end of the century, but those who will, may see a climate that is 5°C (not °F) warmer than today. That would mean vast landscapes that are uninhabitable...

Of course, some evidence for that is required...

Yes, one can with that technology work with relatively little material, but the initial investment still has to be quite something. At least the parts to build the first of these machines and the machines that assemble the new machines from the parts and enough raw materials to produce them until one has at least enough mining equipment to do iron or aluminum mining and smeltering to get new raw materials. These big mining trucks and the houses and fences are not made from carbon fibres or plastics.

There is only a small staff there. Maintenance is already high due to the environment, pointless making it higher is redundant, and just adds extra costs. The initial equipment brought there was minimal (presumably basic materials for resources, plus the stereolithography equipment) - it is also safe to assume that the initial number of people was smaller and a higher proportion of supplies were shipped there at first, and everything that can be manufactured locally is.

It may be possible in theory, but the investment is large - after all you'd have to basically create some kind of barges or cages on a huge scale, probably larger scale than land based agriculture. One would need fertilizers and equivalents of pesticides and herbicides as well. I do not even want to think about what the oceans would look like in such a world - without land plants, the soil gets washed into the oceans, pollutants get into the sea and there most likely would be a problem with oxygen supply. Climate would collapse totally. No, an Earth without land plants certainly could survive with intact marine ecosystems, but with an oceanwide monoculture - in such a short timeframe... I do not think this would really work out.

It isn't about impact, it was about plausibility. I know your particular single interest and how you like to talk about it with every single marginally related topic you can find, but this isn't about current day Earth. It is possible, especially with the degree of industrialisation seen. The point was not what the impact would be, since that was already known. Nobody ever said it took 'a couple of years' - presumably it was developed as land-based agriculture became insufficient and impossible over time.

I'd assume that to travel that distance, they'd have to accel at 1g gravity for the whole travel time (halfway to accel, halfway to decel), so the centrifuges would only be needed in orbit. I calculated this online, and it seems like it is plausible indeed to travel the couple of light years at a constant acceleration of 1G in the timespan provided (6 years), if that calculator tool is programmed right . It still seems like quite a challenge to keep 1G up and running for all that time. -> How to Get to Alpha Centauri | Space.com

Slightly over 1G actually. The crew modules fold flat along the hull for the acceleration/deceleration phase, then use rotation to generate a workable gravity environment during the phase in between (~5 years). The cargo and cryo areas still have no gravity at any point in the journey.

Ok, How would these shields work? Are they SciFi inventions or somehow plausible? I can imagine anything like this would either take quite some material or quite some energy use. Something that can even bother a particle of dust that is travelling at 0.7c must be quite impressive.

...I posted the information
Don't complain if you don't read it.
Again:
There is a shield that is intended to protect against any dust that can theoretically be encountered - a micrometeor can still destroy the ISV, but that is such a small chance as to be negligible - space is big, and empty.
The shield is in multiple layers, spaced one hundred meters apart. Impact of a debris grain (traveling at a relative speed of 0.7C) with the first layer of the shield causes vaporization into a plasma. The spray of plasma particles strikes the second layer, and the impacts cause spalling from the back of the second layer. These particles are stopped by the third layer. A fourth layer acts as a backup in the unlikely event that something gets past the third layer. Once cruise speed is reached, this shield is detached and moved by small thrusters thousands of miles in front of the ship to improve survivability if a larger particle of debris is encountered.

It's in effect a scaled up Whipple shield, while for the vast majority of its journey, the chance of encountering any object is extremely low anyway.

Space is quite empty, but I am not sure how much we know yet of the chance of dust particles hitting. At least in the vicinity of the solar system, there seems to be quite a few of them...

There is a lot of debris around Earth (albeit only in low orbit), but once you get out of the solar system, even hydrogen is extremely rare.

[txen]

A few points for your debate.

Tropical polar regions are a stable configuration. The fossil record seems to indicate that there were dinosaurs at 70 and perhaps more degrees of latitude. We call those areas the arctic or antarctic today and they feature things like permafrost. Now coming up with exact locations is difficult, but it does indicate a much different climate than today.

While the carbon dioxide forcing that humans are applying to the climate will have at least some effect, it's the secondary effects that will make for the big changes. From what I see that will be from two sources. The first is methane releases from both the certainty of melting permafrost and the more uncertain release of methane clathrate. It's a big deal because methane gets a global warming rating 70 times higher than CO2.

I'm thinking that there is a lot of underestimation of the dust density. We really don't know what the interstellar dust density is. However, inside the solar system it's pretty high. The dust detectors on the interstellar probes like Voyager are on the order of 100 cm^2 and get a lot of counts. The problem with dust may well be at the lower velocity ends of the mission in the comparative dirty solar system environments rather than interstellar space.

Another problem is interstellar gas. Luckily for us we are in a low density zone at the moment with only 0.1 atoms per cm^2 compared to the average of 0.5. About 90% of those are simply protons or ionized hydrogen. The problem with them is at 0.7 c each of those protons changes from a gas to a cosmic ray that hits the ISV as at 1Gev. That is a huge radiation problem. This is many orders of magnitude worse than the cosmic ray issue for a trip to Mars.

There are several mitigation stragegies. The fist is placing the hydrogen fuel, water, and any other mass in front of the people. Another is to generate an artificial magnet field and if enough mass is available even an artificial magnetosphere, although an effective magnetic field would have to be massive to bend those 1Gev protons away from the ship.

[auroraglacialis]

Originally Posted by txen

Tropical polar regions are a stable configuration. The fossil record seems to indicate that there were dinosaurs at 70 and perhaps more degrees of latitude.

During what times was this so and does it account for continental plate movement?
I know that there were times this was so, but at least in the last period it was like that, (IIRC that was about 50 Mya) the problem that arose was that the ocean currents stopped working as they do now, resulting in severe problems with marine life, eventually leading to a mass extinction. The worst mass extinction (before the dinos took hold) also was likely caused by global warming and lack of ocean circulation. What happens is the same as happens in stagnant lakes - you get a layer of anoxia near the bottom that can rise. You get H2S buildup that can be toxic. A tropical arctic would certainly not really be a good idea, I'm afraid. At least not unless and until there would be a biosphere evolving that somehow deals with that properly. This is not scientifically proven yet, but there is quite some evidence that such a world has and would be very harmful for many species, including humans and especially the food species they depend on.

While the carbon dioxide forcing that humans are applying to the climate will have at least some effect, it's the secondary effects that will make for the big changes.

Indeed - it is the positive feedback mechanisms that accelerate changes and multiply the impact.

I'm thinking that there is a lot of underestimation of the dust density. We really don't know what the interstellar dust density is.

That is what I also think. Maybe it is really low, but the only way we know anything about that is from Earth based observations and modelling approaches. There is some uncertainty though in respect to those, a lot of space is still unknown (e.g. the famous "dark matter and dark energy" problem). Anyways, I think there is not enough evidence to know if interstellar space is really just a void with no dust to speak of.

The issue of radiation is also very valid. It is already a problem inside the solar system.

Oh and an interestin part would also be - if the acceleration period is really only a fraction of the journey (0.5 years each), would that not mean that most of the acceleration happens inside the solar systems, meaning one would have to deal with all the dust in there?

Originally Posted by Human No More

That's the definition of homeostasis - it fluctuates above and below a certain level

Yes, that is true, but the average level is also not stable. It can shift or rather jump. That all tropical world or tropical arctic scenarios may even be stable in themselves, but the average level is at a different place, so how would people deal with that.
If climate change is pushed beyond a tipping point, the new homeaostasis level may be different than now.

Of course, human activity changes the equilibrium level, but if it is within the capacity of the ecosystem then not so much changes.

Yes, but I think as many climate scientists do, that we are on the way of reaching tipping points and breaching that capacity - or are already beyond the capacity. We definitely are beyond the carrying capacity right now, the amount of degradation rises and it is questionable at what point the system cannot relapse anymore. That is what I also meant with resilience - if a system is resilient, it can return to the average level again. But if they are stretched too much, it wont work. And we are currently not only putting a strain on the parameters like CO2 and Methane but also diminish resilience by eliminating species and ecosystems with other means.

Of course, some evidence for that is required...

Well, it is of course based on modelling, but up to now, the reality usually exceeded the projections - so in away yes - your claim that interstellar space poses no risk in terms of particles and radiation to a spaceship is as based on my claims that climate change will be severe on hypothesis, some evidence and mathemathical and theoretical projections. Only the future will tell.

It isn't about impact, it was about plausibility. I know your particular single interest and how you like to talk about it with every single marginally related topic you can find, but this isn't about current day Earth. It is possible, especially with the degree of industrialisation seen. ...Nobody ever said it took 'a couple of years'

Ok, so lets skip that part mostly to not drag this into my presumed "single interest". But my point is that to develop industrialization more, to reach&maintain a population of 13 billion, to create spaceships, you need a working economy, you need food security, you need energy and you need working ecologies on this planet. Even in a mechanistic view that only looks at how humans can succeed and that does not care in an emotional way for nonhumans there is something we in ecology call "ecosystem services". This ranges from simple things like providing clean water, food, oxygen to more complex ones like a stable climate, protection from toxins or radiation. Right now, we all depend completely on these ecosystem services. Only a few people in the world have the need and can provide the energy to use distilled or deionized water, grow food completely under artificial light or can evade toxins that are in the air by filtration. No one yet can live without healthy ecosystems. Maybe it is really possible to live without them in a sort of "biosphere 2" or even in a purely technological spaceship-type environment. But my argument is that this is not feasible for 13 billion people to do it that way and that it would take quite a few drastic and fast changes and new technologies to somehow keep humanity going without a working ecology on this planet. But as I said, we can skip this discussion in this context, if the intention of the thread is to examine what technologies would be possible and feasible in the "best case scenario".

I have to admit, I am a bit surprised that there seem to be quite a few technologies that already go into the direction as seen in Avatar. I was unaware that space travel to Alpha Centauri would actually be possible in less than 6 years if one can somehow maintain a 1G acceleration.

...I posted the information
There is a shield that is intended to protect against any dust that can theoretically be encountered ...
The shield is in multiple layers...
It's in effect a scaled up Whipple shield...

Ok, thank you for the last link, because my question was not if the shield has layers or that there is a shield that does its job, but I was asking about the technology itself. The Whipple Shield seems to be a shield made of some material like Kevlar that physically absorbs the impact of particles. If this really works on scale and at 0.7c and against single particles I do not know. I am an ecologist, geobiologist and not a space engineer

[Human No More]

You don't need food security to reach 13billion - after all, there is still no such thing with 7 billion. It's likely to have been developed through necessity since it can be presumed that any form of population control was either never practiced or failed in order to result in 13 billion people - as it increased, then both more space and resources would be dedicated to supporting them (especially with profit as a motivation), combined with new developments - for example, the use of the seas for algae would likely have originated in a small scale project that proved successful and was expanded.

As for the shield, that's why they are so much further spaced - existing ones use spacing of a few centimetres as the very maximum, since anything larger is impractical, as well as very overengineered for current requirements. The massive amount of energy involved with anything doing 0.7c is enough to create a plasma from the object.

[auroraglacialis]

Well you need "food security" in terms of not having people starve. Otherwise, the population would decrease by itself... But a unhalted growth to a population of 13 bil would need immense investments and rapid implementation of large scale changes. We are presently approaching the limit of what can be produced on land already - with cheap oil and with industrial farming. There is the reason for China doing land-grabbing in Africa. The step to actually turn the oceans into another monocrop is nothing that can be done now in a few decades - it would take a much longer time while population growth is more or less exponential. So in reality I think (and hope) that such a thing will never be implemented on a large scale because of the investment and insecurities of that. Just think of what a new oil spill or a new Fukushima would do to these algae farms. And all the other contaminants like mercury. To get food in such an abundance from the oceans that people can live on that while destroying the oceans would mean that one literally poops into the own food supply, that is not going to work, unless the ocean water is first cleaned and treated, which is not really working in free floating algae farms in the oceans. The technological development of this kind of food production would be immense and the material investments also. For land based agriculture, you need a tractor and harvester - for these algae farms, you potentially need large constructs of steel or fibres - where is all that material coming from? And we're not talking about a few square miles here but areas that would have to be unimaginably vast. And all that would have to be made in a hurry because land based agriculture is going to be in decline within a decade or two (as agricultural lands are overused, deserts spread and climate change hits)

[Human No More]

So where's the problem with possibility?
Just because you advocate regression does not mean it is suddenly likely or that trends that have existed for hundreds of years will suddenly stop or reverse just because you want them to. There is no such thing as food security with 7 billion people - there is no reasoning to say that is it required for a higher population. Most likely, there ARE shortages for many people. So, I will repeat myself again, although I'm sure you will just ignore the point again - the entire ocean can not be turned into an algae farm in a decade - did I ever say that? No, I did not. But then again, you don't like it when I offer a plausible explanation, and you completely ignored the actual reasoning that it was most likely a gradual process starting off with a small scale project and expanded with investment, likely over decades, as it proved viable and other methods proved insufficient. Population growth may be exponential, but it WILL slow when conditions are not optimal - food shortages are one of these, while that same condition will drive increases in supply. The entire point of algae is that they are optimal for survival and can be made even more so - they are one of the few species that are CAPABLE of surviving in the environment there, and therefore useful for that purpose. Neither was it said that the absolute entirety is completely utilised, just that they cover the majority of the sea. Considering the amount of land use now and the population, that points to a FAR LOWER density, with more area used per person.
I try very hard with you, I keep repeating the same answer when you ignore it, I pointed out in this thread that you are making wishful assumptions based on your own goals which directly contradict canon, but you always repeat the same tired argument.
You treat every single thread you can find as your own political playground to complain, much like several others occasionally attempt to do. You continually complain, you feel you have a right to go unchallenged when doing so, and you complain about people refuting your points even when they are demonstrably flawed, yet attempt to do so with others' yourself. I've had enough. Yet again, you start going on about Fukushima in a COMPLETELY UNRELATED thread, simply because you want to start another argument.

[auroraglacialis]

Fine - if you speak only about "canon", then yes, of course it is possible because it was in the script. But I had the impression that the thread was about the realism behind that and I merely pointed out that I think given the current situation and the upcoming triple whammy of environmental destruction, peaking oil production and climate change are going to be extremely hard to cope with and certainly will make it hard to do large scale projects like massive ocean algae farming. Certainly it is possible - it is also possible that there will be working fusion power and space travel by the end of the century - but I think it is not likely - at the very least it would require juggling all the precious balls perfectly that represent the parameters that could "do us in".

So realistically - feeding 13 billion people almost exclusively with food derived from algae farms - is that possible? I think in the present situation, it probably would be, in the future described in Avatar, I think it would be a lot more complicated, because the oceans are already showing signs of becoming much less hospitable places. Maybe algae can still be grown in any case and somehow purified of the toxins even if the rest of the oceans and lands are dead. Its plausible - if the collapse of ecosystem is going down slow enough to allow people to adapt to it and not tear themselves apart in wars too much - but my opinion is that it is not likely. So in terms of plausability - of course most of the things in Avatar are plausible, they did a great job in not inventing too much things that are just too fantastic. Except maybe the nearly telepathic "link" in Avatars that works unharmed even in the floating mountains where even the sturdy helicopter instruments are failing - that sounds a bit like stretching it.

[Advent]

Originally Posted by auroraglacialis

This is what bothers me about hope. It is a bit like going to Las Vegas and hoping not to loose money. There is a bit of fatalism in hope as in "we can only hope".

Yes well, it's not like we, the common skeptics, can do an awful lot about it at this point in time. To move, Humanity must be pushed.

[Human No More]

The link is likely quantum-based, similar to the FTL communications. The fact that everything in Avatar is realistic and completely possible is one of the things I like over other scifi

[mikkowilson]

Seems like half the technology foreseen by Cameron was already out and available before the movie was!

Especially if you look at what has come to be since 1998.

I think like all good SciFi, it'll serve to inspire the future. Much we won't attain, but other things will far surpass the fiction much faster than predicted.

For example; other than the clear glass screen (which is cool, by the way). Tablets available to the consumer are already capable of much more than was shown of the tablets in Avatar. Yes, even in auto-stereoscopic 3D.

- Mikko ... uses the "Tricorder" app on his phone regularly, for real life tasks.

[Human No More]

Very true, but the design was careful enough that even in the future, it will not look old. Most scifi will look old in the future because they didn't put enough care in, while well done interfaces etc. will have a 'plausible, but diverging path' look and feel even long after they were designed (e.g. Star Trek from TNG onwards).

Also, I have that app. It's interesting with all the things it could do, and just fun to play around with as well

[Clarke]

Originally Posted by Ashen Key

I'm mostly happy with the level of the tech - but actually, I still find it really hard to believe that Jake couldn't get his spine fixed. They can create the Avatars, successfully clone animals, and yet they can't fix cheaply fix the spine of a special forces soldier, with all his hundreds of thousands of dollars worth of training they poured into him?

Hrm.

Massive wealth inequality isn't implausible, but yeah, I can't really see how paying Jake X decades of vet benefits can be cheaper than fixing his spine once, even with American-esque pricing shenanigans. Maybe Selfridge's short-sightedness has infected the accountants.

Originally Posted by Human No More

The link is likely quantum-based, similar to the FTL communications. The fact that everything in Avatar is realistic and completely possible is one of the things I like over other scifi

You can't have relativistic time dilation (as appears to be case on the Venture Star, IIR the math C) and FTL communications without things becoming really weird: the FTL radio works as a time machine if you set it up correctly.

Originally Posted by lumpinger96

There is one thing that bothers me. The Valkyrie Shuttle is stated to be powered by THERMONUCLEAR FUSION.
So they managed to create a Star in a jar and have a 3 Gas giants full of Helium-3 in their own HOME SYSTEM and still have energy problems? --DISBELIEVE--

That also bothers me a little too. Having the combination of the massive energy sources needed for expensive-but-doable interstellar flight and not being able to provide a high quality of life for everyone is somewhat disingenous, and only makes much sense if the general free market is no longer functioning for some reason.

[Moco Loco]

That's something I never actually thought too much about, probably because there could be a huge wealth disparity of some kind.

Wow, what an old thread.

[lumpinger96]

Originally Posted by auroraglacialis

Fine - if you speak only about "canon", then yes, of course it is possible because it was in the script. But I had the impression that the thread was about the realism behind that and I merely pointed out that I think given the current situation and the upcoming triple whammy of environmental destruction, peaking oil production and climate change are going to be extremely hard to cope with and certainly will make it hard to do large scale projects like massive ocean algae farming. Certainly it is possible - it is also possible that there will be working fusion power and space travel by the end of the century - but I think it is not likely - at the very least it would require juggling all the precious balls perfectly that represent the parameters that could "do us in".

So realistically - feeding 13 billion people almost exclusively with food derived from algae farms - is that possible? I think in the present situation, it probably would be, in the future described in Avatar, I think it would be a lot more complicated, because the oceans are already showing signs of becoming much less hospitable places. Maybe algae can still be grown in any case and somehow purified of the toxins even if the rest of the oceans and lands are dead. Its plausible - if the collapse of ecosystem is going down slow enough to allow people to adapt to it and not tear themselves apart in wars too much - but my opinion is that it is not likely. So in terms of plausability - of course most of the things in Avatar are plausible, they did a great job in not inventing too much things that are just too fantastic. Except maybe the nearly telepathic "link" in Avatars that works unharmed even in the floating mountains where even the sturdy helicopter instruments are failing - that sounds a bit like stretching it.

What about hydroponic or aeroponik gardens?? According to the most recent projections there will be 9 Billion people on Earth in 2050, 70% of them in cities perfect for Vertical farming and urban agriculture