Friday, June 28, 2013

The Science of Climate and Geo-engineering… and more

On June 18 I joined a blue ribbon panel (via Google Hangout) on the topic of Reinventing Climate Management: Staring Down the Possibility of Geoengineering, led by scenario thinker Jamais Cascio, author of the book Hacking the Earth: Understanding Geoengineering. He moderated a terrific group of scientists and other innovators (plus me… for comic relief I guess) wrestling with this issue, joined by visitors from the web with questions and ideas.

ReinventorsManaging the climate in the face of global warming is a wicked problem that requires getting almost every independent nation to coordinate. What would a system of global governance look like that's up to the true challenges ahead? And how do we start thinking about whether we need to take more desperate steps in the form of geoengineering?

I came away from the discussion convinced, yet again, that some things merit much closer examination and experimentation.  Out of all of the ideas that have been raised for either removing carbon from the atmosphere or reducing the sunlight that feeds the greenhouse, only one would attempt to emulate nature's own process for removing CO2, the way by far the largest amount has already been removed -- through chemical and biological sequestration in the open ocean. That proposal is Ocean Fertilization.

Yes, yes we have all read about silly, half-baked "experiments" in which poorly instrumented boats dumped tons of iron dust into ocean currents. These created plankton blooms, all right, but also questionable after-effects. They did not get very good press.  And they poisoned the well - so to speak - for more intelligent proposals that would more closely emulate what Nature, herself does.

vanishing-face-of-gaia1And if anyone gets tentative rights to "speak for Mother Nature" it would be James Lovelock, author of the Gaia hypothesis.  With Chris Rapley, director of the Science Museum in London, Lovelock proposed trying an option that would place vertical pipes some 200 meters long in the sea to pump nutrient-rich water from depth to the surface, thus enhancing the growth of algae in the upper ocean. The algae, which are key in transporting carbon dioxide to the deep sea and producing dimethyl sulphide involved in the formation of sunlight-reflecting clouds, should help to prevent further warming. According to his note in Nature: 

"Although fertilizing the ocean with iron as a way of stimulating algal growth is being considered, the use of pipes to use the ocean’s existing nutrients as fertilizer is certainly novel."

Well… novel? Except that ocean bi-layer nutrient mixing was shown to readers way back in my novel EARTH (1989).  Our friend, The Economist's Oliver Morton, wrote an extensive blog on the Lovelock/Rapely proposal -- which may get funding from the Gates Foundation for preliminary research.  And Morton fairly describes some of the critics, as well:

“The concept is flawed,” says Scott Doney, a marine chemist at WHOI. He says it neglects the fact that deeper waters with high nutrients also generally contain a lot of dissolved inorganic carbon, including dissolved CO2. Bringing these waters to the lower pressures of the surface would result in the CO2 bubbling out into the air."

Well, then shouldn't we look into it and find out?

ocean-pipes-1Might this concept be compatible with Nathan Myhrvold’s innovation… pumping warm surface water below the thermocline?  As reported by Oliver Morton, the system would be something a bit like a floating paddling pool with a long pipe dangling down from its centre. Because there will be waves outside the pool but not inside, water will splash in over its edge but not out, and so the water level inside the pool is higher than the level outside the pool, providing the downward force.  A company called Atmocean has in fact built prototype systems which aim to do it in almost exactly the opposite way to the Searete patents, by using wave power to pump cool water up, but the effect would be the same, spreading nutrients from below to where the sunlight is…

…exactly what happens in the world's greatest fisheries, off Chile, the Grand Banks and Antarctica. Why do extra nutrients spur fecundity and ocean health in those places, but not in "dying seas" that suffer from eutrification (death by excess fertilizing runoff from agriculture), like the Gulf of Mexico, the Mediterranean and especially the Black Sea?  Well… just look at them!  The difference should be obvious to the eye. The choked seas do not "drain well."

Let's make a parallel.  It is said that ninety percent of the oceans are "desert" realms where very little lives, because of lack of nutrients to feed a food chain… mostly the stuff that you find in "dirt." Now turn back onto the continents.  What do we sometimes do to make deserts bloom?  Onland we irrigated,  bringing water to soil.  At sea the proposal is to bring "soil" to the water in a sense. (The mouths of most river systems are also generally fecund.)

Ah, you answer, but hasn't irrigation been a mixed blessing, and often a downright curse? Yes! Our ancestors ruined the so-called "Fertile Crescent" by pouring river water over fields, allowing salts and toxic metals to accumulate until the land died.  But this did not happen everywhere.  Many regions -- e.g. the Ganges valley and the Yangtze -- have been heavily irrigated for thousands of years without suffering desertification. Again, the reason should be eye-obvious: Those river valleys had good drainage, allowing salts to be washed away by monsoons.

The Gulf Stream, the Antarctic Current, and the fisheries near Chile are not enclosed seas -- they flow.  So ocean fertilization experiments should start where strong currents can disperse the plankton blooms.  So let's try some of the more natural-like layer mixing or bottom stirring proposals. And let's see if we can make another Grand Banks somewhere.

== Another concept ==

PPS02A truly ambitious concept for ocean fertilization by layer mixing would go beyond those mentioned above.  It would use pipes more than 1000 meters long and power them by planting the bottom end right atop an oceanic hydrothermal (volcanic) vent!  

A thousand meters?  Atop a volcanic vent?  Well… I think we should try some simpler mixing methods, first.

== More factors ==

Again, Oliver Morton (in private correspondence) explained why  the first recourse in ocean fert has always been iron.: "Iron is interesting because its a *micro*nutrient. That gives it great stoichiometry -- you can see in the literature estimates of C:Fe ratios of around 100,000:1, IIRC. That gets you a lot of C for a tonne of Fe. As I understood it you were suggesting mobilising phosphorous reserves in ocean sediments or deepwater. For phosphate fertilizaton the ratio is 106:1 -- the ideal Redfield ratio of C to P in marine biomass. The practical ratio, given losses, would almost certainly be a lot less; for iron it is more than 10 times less. If that were true for macronutrient fertilization, you'd get only a few tonnes of C stored for every tonne of P mobilized. There have to be better ways of getting rid of a tonne of C than that. You might do better -- 10 tonnes C, maybe 30? But that still means a vast mass-moving operation to work at the desired gigatonne C level, because you would have to mobiliza a lot of tonnes of sediment or bottom water to deliver one tonne of P. This is a very different and more extensive infrastructure than needed for iron fertilization."   (See Morton's survey of geoengineering schemes in Nature: Climate Crunch: Great White Hope .)

hackingTheEarthWow.  Okay. Look, I never doubted than iron fertilization was efficient, compared to ocean bottom stirring, or bi-layer mixing.  What I maintain is that not enough attention has been paid to studying the most effective parts of the ocean - e.g. the Grand Banks and Chile and Antarctica -- to determine if they are also big net carbon sinks, as well as fantastic fisheries.  It does not seem to have occurred to anyone that there might be other places on Earth that have almost the right conditions and that might be tipped into similar fecundity with just a little help. 

Instead, the reflex is to assume that all meddling is always bad, all the time.  Indeed, the metaphor I used was irrigation and that was the very reflex. We all know what shortsighted irrigation did to the Fertile Crescent... and that metaphor makes us ignore the lessons of other watersheds that remained productive and healthy for 4000 years.  Again, this is the main difference between Chile, Labrador, Antarctica... and the eutrophic dead zones in the Gulf of Mexico and Mediterranean and Black Sea.

To my knowledge, this consideration was not handled well in most of the iron experiments.

Continue to Part 2 of Ocean Fertilization, discussing Push-Pull Ocean Pumps.

== More using natural forces: Solar Towers ==

Some great ideas have been around for a long time.  Way back in 1989 I talked about desert solar towers that use temperature differentials to suck greenhouse-heated air past turbines, generating electricity for free. A test unit was built in Spain 10 years ago.  


== Climate Miscellany ==


A fascinating survey of how past climate changes, especially in the 17th century, severely affected societies and people worldwide, in The Inevitable Climate Catastrophe by Geoffrey Parker on The Chronicle.


Somebody go read this and review it for us here?  The Age of Global Warming: A History by Rupert Darwall.

==  Plus Science Miscellany! ==

TheVisoneers
With three terrestrial-mass planets in the habitable zone of this small, red star (they would all be tidal locked facing their sun), "the likelihood of one of them actually being habitable is tremendous." Just 22 light years away.

Interstellar Visioneers and a limitless future: Read a review on Centauri Dreams of UCSB Professor W. Patrick McCray's new book called The Visioneers: How A Group of Elite Scientists Pursued Space Colonies, Nanotechnologies and a Limitless Future on the lives of  Gerard O'Neill and Eric Drexler, and how their innovative visions and research into space colonies and nanotechnologies transformed society -- and shaped our future.

Anthropologists see evidence that developing the ability to throw well was a major evolutionary driver.  Something that Bill Calvin hypothesized 20 + years ago in The Throwing Madonna: Essays on the Brain.  Indeed, throwing is one of our many prodigious skills that made us formidable and scary, even discounting "intelligence."



== call my agent… quick! ==

BrainScansPast Brain Activation Revealed in Scans: "What if experts could dig into the brain, like archaeologists, and uncover the history of past experiences? This ability might reveal what makes each of us a unique individual, and it could enable the objective diagnosis of a wide range of neuropsychological diseases. New research at the Weizmann Institute hints that such a scenario is within the realm of possibility: It shows that spontaneous waves of neuronal activity in the brain bear the imprints of earlier events for at least 24 hours after the experience has taken place."

36 comments:

Anonymous said...

A habital planet around a red star just has to be named Krypton.

Carl M. said...

Jerry Pournelle wrote about ocean fertilization as a result of stirring things up back in the 1970s in "A Step Farther Out." 'Twas a side effect of OTEC power plants. (Ocean Thermal Energy Conversion, I think was what the acronym stood for.) Basically running a refrigerator in reverse using the thermal gradient of the ocean.

If hurricanes do in fact increase as a result of climate change, perhaps some OTEC plants in the warm waters where hurricanes spawn would be a temporary fix.

Doris said...

Geoengineering isn't just science; it is also politics.

Increasing one city/state/country's rainfall will probably decrease the next geographical unit's rainfall.

Rainfall wars, anyone?

Anonymous said...

Looks like a typo. When you wrote, "On July 18 I joined a blue ribbon panel..." I was confused, thinking this was a meeting scheduled for later this month. Read that website landing I see it was June 18....

locumranch said...

I particularly appreciate Lovelock's solution to climate change, the mechanical inversion of the ocean's halocline layer, mostly because it coincides with NOAA's worst-case 140 year climate change scenario, the spontaneous inversion of the ocean's halocline layer, which makes me wonder if planet Earth can't solve it's own CO2-related problems without human participation.

Although US agricultural studies have show significant increases in land-based photosynthesis with increases in both environmental CO2 & temperature, Lovelock's approach gains additional support from Australian studies which demonstrate explosive algae growth with a halved doubling time in the presence of increasing atmospheric temperature & CO2 levels which would then lead to an exponential increase in biological CO2 sequestration coupled with a rapid decrease in atmospheric CO2 levels.

All and all an excellent post, scientifically didactic without being morally so, suggesting that climate change CAN be discussed without excessive amounts of 'strun und drang'.


Best.

'loco' ranch said...

Correction: 'Sturm and drang'.

Robert said...

Here's an odd question: would it be possible to simulate environments for the creation of ice in the Arctic Ocean by spraying ocean water into the air to fall back to the ground? In short, something akin to snowmaking machinery? My thought is that when you reduce the surface area of an object you increase the heat loss of it. Thus by spraying large quantities of water upward and probably over existing ice, it cools and then freezes upon contact with the sea ice (as it would be falling on an existing frozen object while having been cooled). You also end up thickening the ice in that region... which helps during the spring and summer as thicker ice takes longer to melt.

Rob H.

Tim H. said...

Talk the U. S. Navy into parking some of their older nuclear subs at the edge of the ice to run the experiment, rather than mothballing them, to eliminate a "Carbon thumb" on the scale. Should work, but bear in mind that an effort to maintain a stasis might screw something else up inadvertently.

David Brin said...

Tim's idea is cool cause Moscow would burn late lights (agh, carbon!) sweating, "why are those yankee subs REALLY there?"

Paul451 said...

Rob H,
Re: Spraying ice.
There's a similar idea for temperate waters. by misting water you cool the air, increase reflectivity, etc. Bill Gates is funding a proposal by Silver Lining. http://inhabitat.com/bill-gates-announces-funding-for-seawater-spraying-cloud-machines/

"it would it take 1,900 ships at a cost of over $7 billion to stop Earth's temperature from rising."

But re-icing the Arctic each year might be a way of leveraging a small number of sprayers for a larger effect. (Since you get much longer term reflectivity from ice, than from cloud.)

Alfred Differ said...

Where does the energy for the pumps that spray the water upward come from?

Misting the water WILL get it to freeze, but the latent heat lost by the water will show up in the atmosphere. Work those numbers along with the pumping energy and check your balances.

At lower latitudes, remember that some of the water will evaporate and water is a green house gas. It typically has a short life in suspended form, but if you keep doing it, you defeat that. Again, work out the forcing numbers for humidity changes. 8)

Anonymous said...

Why such small geo-engineering proposals?

How about Atlantropa? Now there's a real man's geo-engineering project:

http://bigthink.com/strange-maps/287-dam-you-mediterranean-the-atlantropa-project

Then dam the Congo river and divert the water northward into a newly created freshwater Chad Sea. Use this water to irrigate the Sahara, turning the worlds biggest desert into lush farmland and forest:

http://www.xefer.com/2005/03/lake

And that's just on planet Earth.

How about terraforming Mars by the deliberate creation of PFCs (super greenhouse gases):

http://science.nasa.gov/science-news/science-at-nasa/2001/ast09feb_1/

Or terraform Venus by automated machines floating in the upper atmosphere that extract all of that excess CO2 and use it to build carbon nanotube and diamond materials that could be spun into sun screens to further reduce the Venusian temperature:

http://spacefellowship.com/Forum/viewtopic.php?f=16&t=12559&start=0

Even better, send a few machines that not only create PFCs on Mars and carbon nanotubes on Venus, but have 3d printer capabilities and can make more copies of machines like themselves. Which in turn will make more machines, and more machines - increasing in number geometrically until the blanket the planet.

Robert said...

While creating ice mist in the Arctic would result in warmer temperatures in the Arctic, during the winter there is no sunlight above a certain region... which would result in a loss of temperature. It seems to me the end result would be the development of winds toward that region (warmer air rising and being replaced by cold air from the region of the Arctic that gets the least amount of sunlight).

When the ice is thick enough not to be a threat of just breaking up quickly during the summer (and the use of nuclear submarines for this is a grand idea) they can just submerge and move to another area when the ice starts getting thicker. You don't even get long-term winds developed for one area. So you have some environmental glitches but not as serious as just letting the entire thing melt would cause.

Best of all, the sea ice is a NATURAL method, rather than using something like billions of pingpong balls to coat the surface of the arctic or the like to keep the area white.

Robert said...

As for Terraforming Venus... there's two major problems with Venus: its rotation, and its orbital region. These both can be solved eventually by snagging a large massive body, moving it to Venus and setting it in a low orbit. The tidal influences would influence rotation over a long period. Alternatively, by sending an asteroid in a twin slingshot between Venus and Jupiter, it could shift angular momentum from Jupiter to the asteroid and finally to Venus and over millions and millions of years pull its orbit outward. Seeing we'd be doing the same for Earth using mass drivers on the Moon, it wouldn't impact Earth's orbit as much.

Alex Tolley said...

As Carl commented, drawing up cool water for OTEC power plants and using that water to fertilize the oceans was suggested at least as early as the 1970's, and I think even the 1960's. I know I used it as part of my dissertation for my Oceanography masters degree in 1976 where I suggested using the algae to feed fish.

Alex Tolley said...

The question I have about creating algal blooms is whether it really leads to significant carbon sequestration, especially compared to terrestrial approaches. I certainly see fertilization as good for fisheries. Done deal AFAICS.

But carbon sequestration? It seems easier to grow trees and dump them in the deep ocean, or create biochar which both sequesters carbon using simple equipment and improves soil for farming.

Did the discussion have some decent numbers to look at in terms of carbon removal that suggested ocean sequestration by algae was a superior strategy?

locumranch said...

Depending on your reference, algae are the Earth's most important organism, responsible for 70 to 90% of Earth's total O2 production via photosynthetic carbon sequestration.

http://www.ecology.com/2011/09/12/important-organism/

Furthermore, algae doubling (generation) time is very rapid, starting at 6 hours for simple blue-green algae (cyanobacteria), which allows for explosive population growth limited only by sunlight, CO2 availability & the availability of trace nutrients.

http://bionumbers.hms.harvard.edu/search.aspx?log=y&task=searchbytrmorg&trm=cyanobacteria

In effect, algae & other single-celled organisms are the inspiration for (the biological prototype of) human-mediated nanotechnology, whose proven biological effectiveness dwarfs the potential contribution of all existent human technologies (especially in the arena of geo-engineering), so much so that we could start terraforming Venus today, simply by seeding it's day/night transition zones with the appropriate cocktail of algae & cyanobacteria.

It is also the obvious solution to CO2-mediated Climate Change on Earth irregardless of human involvement.


Best.

Alex Tolley said...

This reference suggests that ocean phytoplankton have high productivity (which is why algal biofuels might make sense) but very low biomass. This is in contrast to terrestrial systems, where biomass is orders of magnitude higher, but production slower.

The primary productivity of alga is not the issue, it is how much of that production we can sequester and remove from the carbon cycle. It is useless (for carbon sequestration) if algal productivity is rapidly recycled via other organisms. We know we can grow trees, capture the carbon in wood, and then sequester the wood. With algae, we have to make sure that they can be removed from the surface ocean water and sequestered, possibly as ocean sediments.

Do we have any data on this that would suggest that this is the better to sequester carbon?

A more immediate concern for me is ocean acidification affecting the ability (energy cost) of organisms to secrete calcareous shells. If algal carbon uptake could, even locally, mitigate this effect, that would be very desirable. Certainly much better than trying to push the bicarbonate equilibrium point to reduce acidity by chemical means.

Robert said...

Actually, having the algae be eaten by other organisms is a beneficial mechanism that still removes the carbon from the environment in a manner of speaking. Even if the fish that are fed by the algae end up eaten by people... that's still a section of carbon that has been locked into the environment in a form other than gas for a while.

Rob H.

Alex Tolley said...

@Robert - unfortunately not. We respire almost all the food we eat back into CO2 and water. How much weight have you gained in the last year - none?

Wood is a good carbon store - almost entirely made of cellulose, hemi-cellulose and lignin. Importantly, it has just a trace of phosphorus so that means this vital element is not sequestered way with the carbon. I don't know what the equivalent would be for algae, but I would guess that sedimenting algae would remove phosphorus from teh surface waters which would need to be replaced with the upwelled deep ocean water. Ohosphorus really needs to be separated from the sedimenting algal biomass so that the carbon is sequestered, but not the phosphorus.

Gwenny said...

I have thought about this for years. I think, perhaps, we need to think in terms of redesigning our communities. With all the tech available we could build cities impervious to any of the possible changes. Vertical farms for food, water and power . . . vertical farms that could support dairy and meat and animals for clothes. Something like thermal depolymerization to handle waste. Recycling water. Housing, retail, business, schools and hospitals in large complexes. Good mass transit. I think we could do it.

And massive cities in a Pacific. Found an old brochure about something called The Millennial Project from the 20th century. . .a way to prepare large numbers of people for space colonies. It wanted to build huge floating islands in the oceans.

We know for sure the climate is changing. It has always been changing. Last inter glacial cycle it got 8C hotter . . . 65 million years ago it was 20C-40C hotter. The Earth and life can handle it. It's only humans with their desperate need to avoid change . . . to cling frantically to the single family house, two car garage soccer mom lifestyle that is freaking out.

We can change. We must. Will we?

Alfred Differ said...

Hmm... it is still fishy to me. Liquid water near freezing temp has more heat in it than the ice it becomes at nearly the same temperature. Tossing the water mist into the air enables it to dump its latent heat into the air. The water experiences a phase change and the air warms up. It doesn't matter what time of year it is for this. It's just thermodynamics.

What misting the water does to freeze it is change the albedo. Most heat absorption from incoming sunlight occurs right at the surface, so reflecting it back onto the sky is useful for changing the heat balance. Unfortunately, from what I've seen in the evidence, the ice in the Arctic is being melted from underneath by warmer water from the Atlantic reaching farther north than it used to reach. Increasing the albedo up north won't do much about that unless we try to ice up the North Atlantic. I'd be a tad wary of doing that because it could alter the thermo-haline cycle.

There is still the issue of where the energy comes from to create the mist out of arctic sea water. The engines that do the misting will dissipate much of that energy as heat and dump it right there into the environment along with the fresh ice. It seems to me the air will be a tad bit warmer again.

What an I missing? This seems like simple thermodynamics to me.

Alfred Differ said...

...as for terraforming other planets, lets get real here. There are lots of ideas for how to do it for both Mars and Venus and they might even work, but making that happen would be a bit like getting the Romans to build an interstate highway system like we have in the US all through their empire. No doubt the Romans could have conceived of such a notion, but the wealth required to accomplish that simply didn't exist. What they DID build was justified by the potential income associated with regions of the empire. All infrastructure works like that. Build as you need it, but not too much too early or you destroy the seed capital your empire would have used to grow. The US interstate highway system is the most expensive public works project we have EVER done in our history. The money involved is absolutely HUGE. However, we were making HUGE amounts of money and could finally justify building concrete and asphalt rivers connecting the economic powerhouses in our nation that were not already connected by water and sea.

We WILL terraform other planets, but doing it early would be as dumb as the Romans spending everything to build multi-lane concrete rivers. They didn't need them and we don't need a terraformed Venus or Mars yet. We will when we get out there in an economically significant manner. Until then, they are pretty and harsh New Worlds we will land on and then go home again.

...as for 'terraforming' Earth... we already have. The ice sheets would be advancing by now if we hadn't.

Paul451 said...

Alfred Differ,
"Where does the energy for the pumps that spray the water upward come from?"

Well, David suggested nuclear submarines. :) The good part is that they can submerge if they "paint" themselves into a corner.

"Misting the water WILL get it to freeze, but the latent heat lost by the water will show up in the atmosphere. Work those numbers along with the pumping energy and check your balances."

In temperate waters, it's about "cloud whitening", not just direct cooling. In the Arctic, it's about laying down additional ice. Provided the heat of condensation or freezing isn't high enough to immediately reverse your efforts, then the long term effects from reflecting sunlight will greatly outweigh it. Likewise, by keeping ice from melting, you reduce the open sea, which reduces heat absorption, which further lowers rate of the melting.

However, I suspect there are now too many too powerful people who've gotten excited by the idea of an ice-free summer Arctic sea.

Robert,
The time to use your sprayers is during the summer melt. If you can keep single-season ice from melting before the next winter freeze, it becomes multi-year ice, and is more likely to survive the next summer.

"These both can be solved eventually by snagging a large massive body, moving it to Venus and setting it in a low orbit. The tidal influences would influence rotation over a long period."

Loooong period. The moon, with 1/80th Earth's mass, will only slow Earth's rotation by three weeks over the next 5 billion years. Speeding Venus' rotation by hundreds of days with an asteroid-mass will take... awhile.

Locumranch,
Re: Terraforming Venus by
"seeding the day/night transition"

Because of the thickness of Venus' CO2 dominated atmosphere, there's no cooling on the night-side. So the surface at sunrise is the same temperature as the surface at noon. (Or at midnight. Or at the poles.)

You'd need to have atmospheric bacteria that can stay aloft at the butter-zone altitude (about 50km and up.) And they still need to deal with the acid and lack of water. But even then it won't sequester the carbon (it'll re-burn as it falls). There may even be such bacteria already, just as there's stuff floating in Earth's upper atmosphere.

Paul451 said...

Gwenny,
"65 million years ago it was 20C-40C hotter. The Earth and life can handle it."

The Earth could handle it. The sun in getting warmer, so we are closer to the inner edge of the sun's habitable zone than we were ten, fifty or five hundred million years ago. In response, life has gradually lowered the CO2 level in the atmosphere to almost nothing over the last few hundred million years. And suddenly we've started shoving it back in.

I don't think we'll do anything irrevocable, but never think we can't.

Alfred Differ again,
"The ice sheets would be advancing by now if we hadn't."

There's no evidence that ice sheets were advancing before we started pushing up CO2 levels enough to matter. (The last research I saw put it no earlier than 5000 years from now, ignoring current warming.)

Paul451 said...

"I don't think we'll do anything irrevocable, but never think we can't."

So... many... negatives...

Ian said...

I've been ill for the past couple of days and remain ill.

I'd don't have a lot of time, but just for Paul, here are more of my bizarre, insane rantings about things that will never, ever happen:

"NASA’s Marshall Space Flight Center in Huntsville, Alabama, has 3D printed nickel alloy rocket engine parts using a fabrication technique called selective laser melting, or SLM. The part will be used on the J-2x engine for the largest rocket ever built, known simply as the Space Launch System.

http://www.extremetech.com/extreme/140084-nasa-3d-prints-rocket-parts-with-steel-not-plastic

But, of course, that's done using a very expensive piece of technology that's way beyond the reach of the general public, suggesting that could ever change is as ludicrous as suggesting that computers could end up in every home.

LarryHart said...

Dr Brin,

Once again, I'm going off-topic to ask a question about "Infiity's Shore", which I still haven't completed my third reading of.

Throughout the novel, there are hints that the former tenants of Jijo, the Buyur, actually knew that sooners would end up on the planet and had planned ahead, actually taking into account much of what those sooners would actually perform duing their illegal inhabitation of Jijo.

My question, which is more about the author's state of mind than about actual plot points, is whether you envisioned the Buyur having access to something along the lines of Asimov's psychohistory in order to make such predictions.

Tony Fisk said...

@LarryHart: the short story 'Temptation' has a little more to say about the Buyur.

(Ooh! Number capcha's back: 1614 ngerhni - Buyur home star)

David Brin said...

Been travelling hard and heading out again so much b brief.

AdDiffer: there has never been a scintilla of support form actual scientific communities that an Ice Age impended.

Larryhart, the Buyer would know what traditionally happens during fallow periods. Predictable because it has happened many times before.

Duncan Cairncross said...

As a non American the idea of a civics test before voting has always seemed to make at least a bit of sense

This literacy test makes me change my mind!

http://www.slate.com/blogs/the_vault/2013/06/28/voting_rights_and_the_supreme_court_the_impossible_literacy_test_louisiana.html?wpisrc=flyouts

I think I could answer each question if given pen, paper and enough time - but one wrong answer and its a fail!

Tim H. said...

David, I had to look into this a little last night (The havoc a 19 month old grandchild can do with electronics!) my uverse uses a Motorola NVG510 and I put that into a search and found the default address to the modem page is 192.168.1.254, click "Home network" and I'm guessing you'll want "MAC filtering", since a MAC number will be unique to each device on the network, you will be prompted for an access number, the default # is printed on the side of the modem. Bon chance!

Jonathan S. said...

Does your wifi or gateway not have password-protection? (Mine uses WPA, with a very long password that I had it automatically generate to make it impossible to guess. Not only does it keep other devices out, sometimes I can't get my devices to work with it... :) )

Paul451 said...

Ian,
"but just for Paul, here are more of my bizarre, insane rantings about things that will never, ever happen:
"NASA's Marshall Space Flight Center in Huntsville, Alabama, has 3D printed nickel alloy rocket engine parts using a fabrication technique called selective laser melting, "


You still don't see how 3D printers work (and don't work). In the last thread, I specifically used these aerospace 3D printers as an example of the best that a multi-million dollar facility can produce - they are not new to me.

I said: "So with the best 3D printer money can buy, a million dollar state-of-the-art aerospace monster, you can print out the metal and plastic parts. No explosives, no detonators, no solid-rocket fuel."

A 3D printer cannot print any material that isn't being fed into it. It can't create explosives, detonators and percussion caps, rocket-fuel, etc etc. If your hypothetical terrorists have access to explosives, detonators, etc, then being able to print out a metal casing is not what should scare you about them, and restricting or even banning 3D printers will not restrict their ability to hurt you. And if they can't get access to explosives, detonators, etc, then they can't make an RPG (and they sure as hell can't make a MANPADS).

Paul451 said...

Duncan,
Re: "Literacy" test.

Holy crap. I've got an IQ in the top few percent, which at the very least means I'm pretty good at IQ tests, and yet I had to read several of these questions repeatedly to grasp the twisty meaning.

The worse thing is that many of the questions have multiple grammatically valid answers. For example, initially the questions specify "...in this line", later they drop it. So does "Write the last letter of the first word beginning with 'L'" refer to the "t" in "last, or the "a" in "Louisiana" at the top of the test?

"Cross out the number necessary, when making the number below one million" is a seriously ugly sentence. And does it mean "making the number, which is below, one million"? Or "making the number below-one-million", so crossing out all but one digit is valid (0, 1, 10, 100... are all "below one million")?

The answer to "Spell backwards, forwards" could be either "backwards" or "sdrawrof".

"Print the word vote upside down, but in the correct order". "Correct" in this case could mean inverting the whole word (normal order if viewed upside down), or it could mean inverting the individual letters without changing the letter-order (write v-o-t-e but with each letter flipped in place.)

The directions "northeast", "southwest" in Q23 don't specify whether actual compass points, or the assumed cardinal points if the paper is held north-up.

"Write right from the left to the right as you see it spelled here". So many interpretations: "Write directly from the left to the right as you see "it" spelled here." "Write directly from the left to the right as you see it spelled "here"." "Write "right from the left to the right" as you see it spelled here." "Write from the far left of the page to the far right, as you see "it" spelled here," or again "here". Etc etc.

Q's 28, 29, and 30 aren't even grammatically complete.

Brian Dodge said...

I think you'd want to spray Arctic seawater into the air during winter. The temperature normally in the winter is ~245 k . If the spray was at a rate to keep the temperature at 265 k, it would still freeze, making snow to increase albedo(when the sun rises) and radiating away heat at a much higher rate(about 80 W/m2)*. The brine expelled from the freezing water would carry CO2 into the deep ocean circulation.

*My oversimplified calculations indicate that during winter, a warmed area of 10 million km2 would radiate enough extra energy to account for ~ 3/4 W/m^2 extra global forcing. Transporting that extra energy to the pole would probably change the weather a wee bit.