Interplanetary travel, Arctic sea ice

[JMz]

With all due respect for the jerboas, more problematic might be the assumption that tiling the Sahara would be done in order to produce electricity for San Francisco, instead of for Cairo or Nairobi. (I do seem to recall some deserts that are a few thousand miles closer to SF, however.)

 

[sophiecentaur]

The business of providing photo electric energy is totally separate from reducing the absorption of sunlight on the Earth's surface.
The few unfortunate species that would be threatened by 'painting the desert' would have to be considered as 'collateral' in the interests of all the other species that would have that threat removed. The painting would not involve 100% coverage, in any case but a changing microclimate would clearly have its effect because the local surface temperature would drop significantly over a vast area.
Some intelligent choices of the areas to treat could trigger advantageous climate changes which could increase the tree coverage in other areas and re-establish a half decent overall climate in a short time than has been estimated. Not an easy job,, of course as I keep pointing out to those enthusiasts who talk glibly of terraforming Mars.

 

[mfb]

The few unfortunate species that would be threatened by 'painting the desert' would have to be considered as 'collateral' in the interests of all the other species that would have that threat removed.

With that argument you should work on eradicating humans. A single species gone would remove the threat of more global warming for all others.
I don't think that is a good approach.

 

[nikkkom]

With that argument you should work on eradicating humans. A single species gone would remove the threat of more global warming for all others.
I don't think that is a good approach.

Actually I know a few outlets which just might be... er... progressive enough to produce a few articles on toxic humaninity.

 

[Steelwolf]

I know that in some areas where PV panels have been erected, there ends up being More life growing in the area due to the morning shade allowing the dew to persist a little bit longer, allowing the succulents and the things that depend upon them to thrive. If done smartly, PV panels made with proper full absorption or at least what is not absorbed reflected back to space so as to reduce the heat as is initial requirement.

White a-frame type fencing could be used in the near polar zones, especially since during fall and spring it would shade the ice and snow to a greater extent and allow it to last longer before melting. Fencing would have to be staggeed on a short scale, which is easily doable, so as to allow wildlife free travel thru the areas, care must be taken not to cut off migration or obvious game routes/trails taken into consideration so as to not trap the animals in unsustainable grounds. This would be cheap and easy to maintain, also giving jobs to people in the area. Mainainance of PV and fencing (which can also be combined) would provide some decent pay jobs with the 'rough' working conditions some prefer.

 

[rbelli1]

near polar zones

Solar panels in near polar zones will produce little energy during the summer spring and fall due to the steep angle of the sun and no energy during the winter due to total darkness.

BoB

 

[sophiecentaur]

Solar panels in near polar zones will produce little energy during the summer spring and fall due to the steep angle of the sun and no energy during the winter due to total darkness.

BoB

Polar zones also tend to be whitish so it's only when they are melting that we could change their reflectivity. Also, there's not a lot of point in painting or siting PV somewhere that will have snow for many months.

 

[Steelwolf]

@ Sophiecentaur and BoB, the idea is mostly building the fence in the polar zone for the shade (to keep the snow from melting by providing shaded areas) alone as for too much of the year it is impractical for power generation, however, ever for the small bit of the year they are usable, PV's could, and would be used. But primarily I am looking at the A-frame style tall fencing as a snow-shield shading device on the ground, rather than in space, and working off the same principles of the lowered angle of the sun, with the fence, shades a much larger area of snow than the fence itself actually is. Shadows are great things. Using the area for PV during summer months is a doable thing for local communities only, would not work for large expanses.

But for shade emplementation, it does not need to be powered. That is mostly for comfort and survival of the workers and people living in the area, not as a general power idea, and certainly not a year round thing either, but the shade may well be needed in the next century, it might help improve sea-ice levels. Dunno, just ideas to explore.

 

[stefan r]

...would have to be considered as 'collateral' in the interests of all the other species that would have that threat removed...

Ecofascism! I tried telling people it would happen.

One of the simple fixes is to bring back buffalo in North America. Buffalo grass does fairly well for shielding the ground and deeper roots sequester carbon. A relatively small group of volunteers following the herds could clear barbed wire with bolt cutters and use sniper rifles to shoot any threats to the buffalo.

We also have autonomous self replicating robots that use biomass for fuel and collect vast sheets of ice in the winter. They also pressurize the water table with cold oxygenated water. The robots are called beaver.

 

[sophiecentaur]

Ecofascism!

That's one way to look at it.
But there's a dilemma here. Do you swerve left to miss the old lady on one side of the road or do you swerve right to miss the class of schoolchildren on the other side? Left to itself (and to continuing human development) the temperature will go up and there will be (and there are) extinctions. One way to counter climate change is to reduce the amount of sunlight absorbed. There is the 'space' solution, the 'paint' solution and the 'biological' solution.
You have introduced the idea of a biological solution and that would also affect many species in an unplanned (unpredictable) way. It would have its place and would need to be engineered sensitively, just the same as the other methods.

I do like the idea of snipers, picking off the would-be Buffalo Bills with their SUVs and hunting rifles. A new range war?

 

[JMz]

I still think we are too hung up on physical-science solutions. (Understandable: This is PF, after all.) But the problem seems more in the social-science realm. I suspect, for instance, that there would be social interference with the sniper "solution". Just a guess. ;-)

 

[sophiecentaur]

But the problem seems more in the social-science realm.

Of course, but avoiding the problem was also in the Social Science realm and we didn't manage to. I doubt that, even if we reduced our greenhouse footprint now, things would necessarily return to a safe level without some other strategy.
It's a Catch 22 situation, though. The whole economic thing relies on expansion and people will never change.

 

[JMz]

I doubt that, even if we reduced our greenhouse footprint now, things would necessarily return to a safe level without some other strategy.

Concur. The harm will be widespread unless a technological component is also part of the solution. (That's where we come in! ;-)

 

[stefan r]

Concur. The harm will be widespread unless a technological component is also part of the solution. (That's where we come in! ;-)

We could use inflatable dams in the rivers in North America starting around August. Would increase ice coverage and lower the temperature in the water table. Deflate the dams late winter.

Of course, but avoiding the problem was also in the Social Science realm and we didn't manage to...

Society and especially democracies tend to get stuck in binary thinking. The media tends to amplify that effect by insisting on presenting exactly two views on things in order to remain "impartial". If you start a debate on whether or not reality is really happening then one of the parties will end up championing non-reality.

The solution is to present the public with 2 parties where each one supports an alternative option. Choice 1 is to launch 6 billion solar sails. Choice 2 is to destroy the drainage system. It can be hard to predict which party will win a general election. Other issues get mixed in so some people will support destroying the drainage system because of party affiliation even though they really do secretly like big rockets. As an isolated idea it would be nearly impossible to convince the US public that destroying the drainage system is a good idea. Core support starts when people hear that the opposition thinks launching the sails is a better route than the ice dams. SpaceX and Boeing-Lockheed will probably donate campaign funding to sail-supporting congressional candidates. If you do not vote to backup the drainage system then you "wasted your vote".

If you really want to paint the desert you could stick that in as a rider. Might be easier to claim it was to create jobs in the south west. Get paint manufactures in the northeast to lobby their congressperson. Keep the argument focused on whether or not Washington should worry about factory workers in the northeast and painters in the south west having a job.

 

[rootone]

I propose those 500nm light-reflecting, self replicating carbon-based nanostructures.

You mean plants?

 

[sophiecentaur]

If you really want to paint the desert you could stick that in as a rider. Might be easier to claim it was to create jobs in the south west. Get paint manufactures in the northeast to lobby their congressperson. Keep the argument focused on whether or not Washington should worry about factory workers in the northeast and painters in the south west having a job.

I was really thinking in terms of method that would involve very little cost by minimising the number of workers involved. The problem is that the most suitable places for 'painting' would not be the most accessible nor the sort of places that humans operatives would work best. I was assuming large areas being part-covered by aerial application. These days it would be cheapest by drone. The difference in cost would probably outweigh the 'employment' argument - but I see where your'e coming from. I would have thought that 'making the desert bloom' would be a good selling point. The 'blooming' would be in the gaps between the painted bits, when the rain starts to fall due to the lower local temperatures.

 

[sophiecentaur]

even though they really do secretly like big rockets.

I have a big problem with that attitude that starts with the method and finds applications for it.
Since I bought my new Multi-Tool, I have found all sorts of little jobs to do with it. But the cost of the machine was very low.
I am not particularly in love with drones or paint brushes.

 

[nikkkom]

I'm hearing the "omg omg we are all going to die from global warming" thing almost as long as I remember myself.

The effects are seen, but they are rather small. 20 cm sea rise in the last 100 years, and such.

Interestingly, as some dire predictions' time came and they failed to materialize (Arctic did not completely melt by 2014, West Side Highway not underwater), another type of "global warming" became evident: if you are not sufficiently scared and dare to say that it's not such a big deal and we probably will be able to deal with it without drastic civilization-scale efforts, you might find yourself roasted. Actually, scratch "might". You WILL find yourself roasted. It's socially unacceptable in "scientist circles" to be insufficiently worried by GW.

 

[mfb]

The effects are seen, but they are rather small. 20 cm sea rise in the last 100 years, and such.

Significantly more tropical cyclones
More extreme precipitation
Much more extreme low temperatures
More extreme high temperatures
All as graphs
This is what we have today. Future warming will make all these things worse. Here are some estimates.

By the way: 20 cm sea level rise might sound small if you don't live close to the sea, but in Bangladesh for example 20 cm means the sea moves many kilometers inwards.

 

[nikkkom]

By the way: 20 cm sea level rise might sound small if you don't live close to the sea, but in Bangladesh for example 20 cm means the sea moves many kilometers inwards.

I did live near the sea. Therefore I know from my own experience that 20 cm is insignificant. Waves are usually higher than 20 cm even in calm weather, and tides are higher than 20 cm even in insular seas. On the ocean shores, they are usually in the range of meters.

 

[JMz]

I did live near the sea. Therefore I know from my own experience that 20 cm is insignificant. Waves are usually higher than 20 cm even in calm weather, and tides are higher than 20 cm even in insular seas. On the ocean shores, they are usually in the range of meters.

Go back to the Bangladesh point. And the fact that most of the warming from current human activities has yet to occur.

Will humanity go extinct from this (or from the wars that ensue over it)? No. But there are many dire effects short of that, and most of them are unpriced by people who prefer the benefits of the status quo. (The insurance companies are an exception, although even they aren't concerned about effects 30 or 100 years from now, when their existing policies will have renewed at appropriately higher premiums... or when they will have exited the insurance business.)

[Edit: Removed an initial, erroneous sentence from a different reply.]

 

[sophiecentaur]

I did live near the sea. Therefore I know from my own experience that 20 cm is insignificant. Waves are usually higher than 20 cm even in calm weather, and tides are higher than 20 cm even in insular seas. On the ocean shores, they are usually in the range of meters.

"I know from my own experience" would allow you to take up smoking, not to buckle your seat belt or refuse to have a child immunised. Statistics can have big effects on large numbers of people. It is not valid to express strong views / beliefs about such things until you understand about Statistical Significance. If you really need a personal experience to believe something then why are you making and reading posts on PF? For the past hundred years, at least, many of the "Scientific Facts" that have emerged have been based on results with high variation. CERN's results are always based on statistical evidence and a very fuzzy needle on their meter.
Events due to coincidence of Tide, barometric pressure and wind direction that used to be considered a 'Once in a Hundred Years' have become 'Once in Ten Years'. The Thames barrier is a good example.

 

[nikkkom]

"I know from my own experience" would allow you to take up smoking, not to buckle your seat belt or refuse to have a child immunised. Statistics can have big effects on large numbers of people. It is not valid to express strong views / beliefs about such things until you understand about Statistical Significance. If you really need a personal experience to believe something then why are you making and reading posts on PF? For the past hundred years, at least, many of the "Scientific Facts" that have emerged have been based on results with high variation.

In this case, I'm not referring to what happens to me, and not making statistical inferences. I'm referring to having experience with the sea, waves, tides in general. Statistics does not enter this picture. 20cm is insignificantly small sea rise, mitigation is trivial. Netherlands mitigated about 7 meter local "sea rise" due to subsidence. They have designs how to counteract 7 more meters of sea rise if necessary.

 

[sophiecentaur]

In this case, I'm not referring to what happens to me, and not making statistical inferences. I'm referring to having experience with the sea, waves, tides in general. Statistics does not enter this picture. 20cm is insignificantly small sea rise, mitigation is trivial. Netherlands mitigated about 7 meter local "sea rise" due to subsidence. They have designs how to counteract 7 more meters of sea rise if necessary.

Not all 20cm rises have the same significance.
The Netherlands are rich enough to cope with the results of a 'brief' overtopping of their sea defences. There are flood reservoirs (or some such term) which can cope with an overtopping of a few minutes or a couple of hours and they can be pumped out over the medium term. Poorer countries have no such facility. If your 'sea wall' happens to be a sand bank, a small wave can trigger a massive flood as it washes the top away. Some growing land is lost for ever. It's a different situation entirely. Bangladesh are constantly losing agricultural land and it will get worse if there's 20cm of maximum sea level. You can ignore that if you want to but it's really happening to some 'other people'. I imagine you would be prepared to lend some money (assuming you had a spare $100k) to a house building project in the Netherlands. Would you honestly be prepared to lend the same money to a farmer in Bangladesh? Why? (I have already assumed your answer.)

 

[nikkkom]

Poorer countries have no such facility.

<< Mentor Note -- Post edited to remove offensive content >>
I'm from a poor country, unlike you. Let's listen toy somebody from a poor country, shall we?

Poor countries will continue to have tons of problems as long as they are poor. The only solution to this is to help them to become more prosperous. For this, we we need to fix the _reason_ why they are poor: bad governance, lack of democracy, corruption, and cultural reasons which prevent those things from being changed.

You can ignore that if you want to but it's really happening to some 'other people'. I imagine you would be prepared to lend some money (assuming you had a spare $100k) to a house building project in the Netherlands. Would you honestly be prepared to lend the same money to a farmer in Bangladesh? Why? (I have already assumed your answer.)

Donating $$$ per se does not help. It did not much help for my country - this "help" almost entirely gets stolen by the local ruling... er... "elite"... with the help of NGOs, some of which increasingly looking like being designed to perpetuate the flow of said "help".

But since you already "assumed" that I'm willing to help Netherlands but not poor << Deleted by Mentor >>

 

[sophiecentaur]

<< Quoted text deleted by Mentors >>

I was talking in terms of Investment and not 'help'. With help you don't expect get your money back.
PS Where did this Nazi stuff come from? I was arguing statistics and how to interpret them. My only point was that personal experience is never reliable and I assumed that the question of putting one's money where one's mouth is tends to bring out one's rational streak. I cannot defend myself for being comfortably off but I do count my blessings.

 

[nikkkom]

Hmm. I'll try to dial back my at times confrontational and snarcastic style.

I am indeed from a poor country, and I have something to say about how well-meaning people go about helping such countries.

Just throwing money, or humanitarian supplies on them usually does very little good. Basically, shipping food to 10 million starving Somalians, in the best case, will save many of them from dying. But if you do that, and do nothing to change what's happening in Somalia, in 15 years you will have 20 million starving Somalians. Rinse, repeat.

There's a way to do better.

You need to (1) research the problems this country has, (2) force people who benefit from current situation to change this situation. (Naturally, the resistance will be immense).

There are people in all these poor countries who can give you necessary information. There are young, still idealistic and not-yet corrupted politicians. There are investigative journalists. And Western countries do have spying agencies who are professionals in analyzing data (among other things they do).

Money and/or humanitarian supplies have their uses as tools to persuade corrupt local politicians to do reforms they would rather not do. "Oh, mister Prime Minister? You are bankrupt, you need IMF loan or else you will default? Sure, we might help with that. But here's this 'Freedom of Information Law' we are talking about for the last year, and you are stonewalling it despite your party having 77% in your parliament. How about you guys vote for this law, and *after that is done* we give you the loan?".

_This_ use of $$$ would help. Used consistently, it can help _a lot_.

Sadly, I rarely see Western financial assistance used in this way. More often, it's like "we will finance a hospital construction". Do you plan to finance all our hospital construction in eternity?

 

[stefan r]

You mean plants?

There is the azolla event. It is not correct to claim humans are the only species to change the climate.

Hmm. I'll try to dial back my at times confrontational and snarcastic style.

This thread is sliding off topic. The original post was about using physics/engineering to tamper with the climate. Wearing tin foil hats to reflect more sunlight by increasing Earth's albedo is on topic. Simple ways of avoiding the problem, like birth control or cannibalism, are not high tech methods of forcing the climate to cool. Deciding that you personally do not care about global warming or you do not worry about runaway feedback should not matter. Designing something does not mean that you want it to be used. We can figure out who is responsible for what in a polisci or sociology forum.

I noticed that we are on 4 pages of replies and only one post addresses this:

...converting the potential energy of the asteroid's current stable solar orbit, into a free-ride to a distant planet using less on-board propellant than it would otherwise use going direct?
.

Bandersnatch covered it in post #2.

...You don't gain any energy from riding an asteroid and then detaching from it, while you do need to expand (a lot!) of energy to change its orbit...

Gravity assists, tethers, and mining of asteroids/comets for volatiles are ideas that utilize objects in space for momentum and can reduce launch mass.

A 1 km radius asteroid could produce millions of square km of foil. Solar shades do not need to be launched on rockets from Earth. You can also use sunlight to move the foil into place. At 1 au the force on a million km of foil is greater than the 3 main engines on the space shuttle (5 x 10⁶ N).

 

[sophiecentaur]

A 1 km radius asteroid could produce millions of square km of foil.

How do you suggest that could be achieved as conveniently and cheaply as manufacturing on Earth? OK in principle but it needs to be thought out in detail before it's worth considering. Capturing a suitable asteroid is not trivial.

 

[berkeman]

Thread closed for a bit for Moderation...

 

[berkeman]

I don't know if this will work, but thread re-opened after some clean-up. Let's please try to stay on-topic an civil. Thanks.

 

[stefan r]

How do you suggest that could be achieved as conveniently and cheaply as manufacturing on Earth? ...

Rolling and extruding should be easy to do in space. There is no atmosphere so you can keep the material hot and you do not need to worry about oxidation. Extremely long pieces are reasonable in free fall. On Earth a railroad track or a building column ships in truck length pieces which are welded later. If you have the steel in space you could directly extrude a track the length of a continent. Hot rolling long sheets should be easy. The width is limited by the size of roller you are willing/able to manufacture. The rolls will need coolant and radiators for the coolant. If you are content with long thin strips then rolling is easy. Sheets can be stacked and rolled again. That can be used for mixing.

There will be challenges replacing parts of processing that use gravity. The traditional iron refinery blast furnace would not work. Slag does not float. Quenching would be tricky.

Since the only stress on our sheet is from sunlight then rolled, slow cooled, pig iron is easily good enough. People will want something higher quality for habitats and storage tanks. Some of the other elements might be usable too. Magnesium and sodium are not fire safe so we do not use them much. The should work fine for a reflective film.

 

[sophiecentaur]

and you do not need to worry about oxidation.

Are you expecting to find pure metals out there? From what I have read, metals will be in the form of ores, which need to be extracted. The reducing chemicals would need to be imported in comparable mass to the metal you get out.
I think you need to rethink your proposal to take that into account. Processing pure metals is the least of your problems.

 

[stefan r]

Are you expecting to find pure metals out there? From what I have read, metals will be in the form of ores, which need to be extracted. The reducing chemicals would need to be imported in comparable mass to the metal you get out.
I think you need to rethink your proposal to take that into account. Processing pure metals is the least of your problems.

Most of what I have read about ISRU the oxygen is one of the goals. The oxygen gets used in rockets. There is a lot of metallic iron in asteroids. Carbon is also common in asteroids and that is used on Earth for iron redox. Ancient Egyptians worked meteoric iron into finished pieces without refining. Forging can remove some impurities. Modern pig iron is not a pure metal either.

 

[sophiecentaur]

Modern pig iron is not a pure metal either.

I smiled when I first read this but it's not totally daft to conceive a very crude structure, 3D printed of course, made of pig iron or any other half-refined metal ore. We wouldn't need to worry about it going rusty. It would just need to stick together.

The rolls will need coolant and radiators for the coolant. If you are content with long thin strips then rolling is easy. Sheets can be stacked and rolled again.

The structure would be 'open' and, as I mentioned above, the best construction may not be with sheets (an intermediate process needed) but fused pellets.
But this whole project strikes me as a tube piece of vandalism, much worse than painting selected areas of the surface. Space communications, astronomy and even transport could be affected.