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Comment Re:Yes and? (Score 1) 149

As long as the conventions are understood and consistent, then who cares if all strings have to be null terminated or if the strings returned as static, garbage collected or must be free'd?

That information has to be encoded somewhere. If your convention is that every char* parameter is a null-terminated C string that must be copied by the callee if it is expected to persist beyond the duration of the function call, then that's great (you'd better be really consistent about not using char* for arbitrary data though). Similarly, if every pointer that is returned needs freeing by the caller, then that's also fine, and you can machine-generate the wrappers on that assumption.

If you're going to create a metamodel with the primary goal of allowing wrappers from other languages, then you need to think about these things. EFL now has a metamodel intended for FFI, and it doesn't think about these things. Functions take char* arguments (and the metamodel describes their type solely as char*), which may be null-termianted C strings or blobs of data with the length encoded somewhere else. They may be held by the callee and freed later, or the caller may be responsible for freeing them. None of this information is encoded in anything machine readable.

Comment Re:Let's just not do it. (Score 1) 167

The main problem I see is that it seems like you're making a lot of assumptions based on geology here on Earth, such as which minerals are likely to be present at sites with particular geologies. Doesn't that depend a lot on the early planetary formation?

Chemistry works the same everywhere. What elements readily form compounds with other elements is the same everywhere. At what temperatures minerals begin to crystalize out of magma is the same everywhere. Etc. Economically valuable deposits of resources are locations in which chemistry tended to concentrate that mineral and leave it at an accessible location. The same parameters must apply to the moon just like on earth.

Also, correct me if I'm wrong, but I thought I had read that, just like you say with the Moon and heavy elements sinking to the core, the exact same thing happened to the Earth, and as a result, we have no heavy metals, including iron(!), accessible here on the crust left over from the formation of this planet.

90% of the mass of the Earth is oxygen, iron, silicon, and magnesium. And these chemicals tend to form compounds with each other. Consequently it's impossible for "all of the Earth's iron", for example, to have sunk to the core. More to the point, these oxides aren't as dense as the pure metals. For example, in the crust a lot of iron is found as limonite (that yellowish-orange color you often see in clays), which can be nearly as light as quartz. The largest single mineral component of the mantle (and thus the Earth) is olivine (commonly known as peridot when sold as gemstones), a magnesium iron silicon oxide.

Unlike the outer layers, earth's core is predominantly metallic iron, not oxides, and thus far denser. It's also highly enriched in many heavier elements which either don't readily oxidize or form heavy oxides. For example, platinium is found at about 5ppb concentrations in the crust, but is believed to be about 6ppm in the inner core, over a thousand times greater concentration. Uranium, thorium, gold, and countless other elements are vastly more common in the core than the crust. That doesn't mean that they're absent elsewhere. Even ignoring deposits from bombardment, you will often find small amounts of rarer elements in minerals with elements that they're chemically similar to.

You can see the nature of mixtures in what erupts to the surface as lava - an igneous flow will ultimately crystalize out into a wide range of tiny mineral grains - various feldspars, quartz, various iron oxides, etc. These crystals have different densities, and they're made from elements with different densities - but the forces keeping them in solution are greater than the forces working to fractionalize them. Differentiation inside magma takes a long time - for example, to get basalt rich in large olivine crystals, like picrite, the magma has to sit and slowly cool over many thousands of years, allowing the olivine time to crystalize out and the crystals time to settle to the bottom without the bulk of the magma hardening and trapping it - then the upper olivine-poor magma erupting, then the olivine-rich magma erupting (again, all without hardening to the point of becoming trapped in the magma chamber).

Or, to put it another way: salt is heavier than water, but the bottom of the oceans is only slowly increases with depth (and is highest near the surface where water evaporates, but that's a side point). It's a lower energy state for the salt to dilute than to all collect at the bottom.

nd that all our valuable ores (iron, gold, silver, even tin and lead) came from asteroid impacts over the eons, which is why they're concentrated in particular places.

That's not why elements are concentrated, as a general rule (although there are exceptions). Most concentrates are due to various geological processes involved in preferentially enriching or depleting minerals from a bulk. For example, you know the old miners' saying, "Gold wears an iron hat" (gossan) - do you know why that is? Iron and sulfur-rich rock tends to contain pyrite. Pyrite plus groundwater (and with the aid of bacteria) over time produces sulfuric acid. The acid leeches the rock around it. The minerals that dissolve in the acid concentrate where the water reaches the surface, often leaving iron stains/deposits, along with deposits of other dissolved minerals such as copper, which tend to precipitate out together. The minerals not eaten away by the acid (quartz and resistant minerals, including gold) tend to be concentrated underneath

(Totally unrelated side note: I actually have an iron bog on my land, and as a geology nut I find it fascinating, when most people would just find it disgusting muck ;) One of the IMHO most interesting characteristics is what looks like oil slicks on the surface. But if you actually touch them, you see that they're not a liquid, they're an iridescent film. It's a consequence of iron-metabolizing bacteria oxidizing Fe+2 to Fe+3 and releasing goethite as a byproduct. :) )

That's just one example of a process that concentrates minerals - there are countless. But in the world, wherever something is economically exploitable, there almost always was some sort of geologic process that highly concentrated it there.

And while it sounds like we understand a good deal about geological processes, I'm not so sure it's that complete: didn't we only figure out the southern part of Mexico was formed by a giant asteroid impact within the last few decades, and that that was the cause of all the caves and such along what's left of the rim of the crater?

The Chicxulub crater was discovered four decades ago, in the late 1970s. And in terms of our understanding of geology in general, that's a huge length of time. Remember, it wasn't until the 1960s that plate tectonics and the concept that large bodies still impact the Earth became the scientific mainstream. Modern geology is somewhat "young" compared to the other sciences. The foundations of astronomy became solidified people like Galileo and Copernicus, classical physics with Newton, etc, but even around 1800 variants of a "Noah's flood" theory were still mainstream in geology (the "Deluvian" or "Neptunist" theory), and the fact that fossils tended to align into layers was a newly discovered curiosity (commonly explained by the Neptunists as due to how they'd settle out in the ocean or flood).

Anyway, with asteroid impacts, the moon is full of them, as we can see easily with a small telescope, and unlike the Earth, there's been little tectonic activity and no atmospheric or water-based erosion. So wouldn't that mean that each impact site could potentially have a lot of valuable ores?

Impacts really don't work that way. Impacts over a certain size are basically converted into plasma on impact and explode. Even on earth, this does little to create economic deposits of minerals, as it's so spread out. On the moon, with low gravity and no atmosphere to get in the way, you're spreading the body of your impactor over vast distances.

There is one way in which impactors do sometimes produce valuable deposits, mind you. The aforementioned Sudbury deposit is a good example. The impact, as mentioned, blasted material all over the Earth - it was utterly obliterated. But the impact was powerful enough to create a melt pool all the way down to the upper mantle. The process in which it differentiated and cooled is complicated, but you can read about it here. But the key takeaway is, the deposits are overwhelmingly from the crust and mantle, not the impactor.

You also mentioned titanium being plentiful there. Wouldn't that be a good enough reason? Titanium isn't exactly cheap here.

No. First off, even titanium metal is cheap here - about $10/kg, which is nothing (platinum, by contrast, is $30000/kg, and there are countless things far more expensive than platinum). When your launches cost tens of thousands of dollars per kilogram (and even after future process refinements will still probably cost thousands), mining something worth $10-20/kg obviously is not going to pay off. But more importantly, most of the cost of titanium metal is refining titanium dioxide. Titanium dioxide, after milling, costs about $5/kg. It's so cheap that it's the predominant white pigment used on Earth (white paint, sunscreen, etc... pretty much anything that you want to be bright white uses titanium dioxide).

How much fuel are we wasting because we still build cars out of steel instead of titanium?

Honestly, the main reason cars are mainly built out of steel is process-based. We have long-established historic processes for mass-manufacturing vehicles out of steel. Composites are generally much stronger per unit mass, and the raw materials costs can be kept lower than steel (glass or basalt fiber rather than carbon, vinyl ester instead of epoxy). But it's much harder to mass produce out of composites than steel - it's hard to get automated processes to produce parts of consistent quality.

Titanium is $10/kg. Aluminum is $1,50/kg. Steel is about $0,35/kg. So while none of these are "expensive" materials per kilogram, obviously when you're mass-producing multi-tonne objects the difference matters. Automakers are more and more incorporating aluminum into vehicles to (borrowing from Lotus) "add lightness". But it's also important to know that these materials aren't just simple substitutes for each other. Aluminum is 1/3 the mass of steel, but also not nearly as strong, and with a much lower melting point. Titanium has a high melting point and is roughly as strong as steel. Aluminum is generally harder to weld than steel, and titanium much harder to work with in general than steel. Also there's the issue of experience - there's more people with experience working with steel than aluminum, and vastly more with experience with aluminum than with titanium. The rarity of people with experience working with the metal makes such employees more expensive to employ.

The (former) wide availability of titanium in the former Soviet Union was not due to the widespread sourcing of titanium ore, but rather the communist government prioritizing it as a war resource and pumping large amounts of money into its production.

Venus is completely inhospitable at the surface for both humans and machinery, so I have no idea how we'd exploit mineral resources there.

I already discussed this. Google "phase change balloon". Keeping things alive for hours at the surface is not a problem - the Soviets did this with the Venera landers. You simply have to have a thermal mass to act as a cooling reservoir. Once your thermal reservoir becomes too hot, you have to return to altitude to cool or replace it before making your next "dive". It can be thought of as rather akin to mining the seafloor. Due to the limited time per dive, this would be grossly impractical to try to control such equipment from Earth - you need people "locally" to get rid of the latency issue. Hence the reason why there's actually some logic to putting humans on Venus.

If the Soviets could run sampling equipment on the Venus surface on a shoestring budget with 1960s/70s technology, there's no reason that we couldn't have surface mining equipment today. But obviously, every case comes down to economics.

Comment Re:Let's just not do it. (Score 1) 167

First off, our knowledge of the moon is not "some rocks the Apollo astronauts brought back". The Moon is one of the most studied bodies in the solar system, perhaps the second most studied. We have a pretty good idea of what makes it tick. There have been 70 successful or partially successful (overwhelmingly completely successful) missions to the moon, plus some considered "spacecraft failure" that still returned data. 6 of the successful missions are operational right now. There have been 16 missions to land softly on the moon, one of which then re-launched and landed again. There were also two impactor missions to kick up plumes for study. There have been 8 sample return missions, another of which is scheduled for 2017. Modern advanced orbiters have conducted detailed spectral scans of the whole moon and mapped details down to 50 centimeters. We know the thing pretty damned well. It wasn't until the second half of the 20th century that we even knew the Earth that well.

The moon is fundamentally disadvantaged when it comes to valuable mineral resources. Most valuable, rare mineral resources are heavy, as these tend to sink deep into planets during formation, leaving them depleted from the surface. The moon was formed in a collision whose dynamics left most of its heavier materials on earth and left it with lighter materials from itself and Earth. That's not to say that all light minerals are worthless - far from it. Beryllium is worth over $1k per kilogram, and it's quite a light element. But things like that are the exception, not the rule. The moon was then doubly disadvantaged in that the collision left it with a global magma ocean (with no tectonics to recirculate deep crust back to the surface). This led to crystals of lower-melting point and denser minerals to almost universally sink to the bottom, leaving the top layers rather monotonous in composition (a universal plagioclase crust). While various geological activities subsequently modified it (primarily impacts and, long ago, the mare basaltic flows), it was disadvantaged from the beginning.

Then there's the fact that minerals don't just pop up randomly - they need geological phenomena to concentrate them to economic levels, and they're found associated with various geological features and/or tracer minerals. For example, the aforementioned beryllium is found in granitic pegmatites associated with tin and tungsten. The moon has no granite - thus no granitic pegmatites. There are a few other types of minerals beryllium concentrates in, but they don't exist on the moon either. This doesn't mean that there's no beryllium on the moon - there is, it's been studied. But there's nothing to concentrate it to interesting quantities.

The biggest modification to the original lunar rocks has been the formation of the mare. These are ancient mass flows of tholeiitic basalt - not much diversity, except in the concentration of titanium. Lunar titanium concentrations are much higher than on Earth. However, titanium oxides are very cheap, common minerals. Melt pools from impacts also have the potential to be mineral concentrators (on Earth, the Sudbury impactor created some highly valuable mineral deposits in Canada). But there are two problems. One, these tend to solidify deep underground, meaning your mining becomes far more difficult and hardware/labour intensive (on a body that costs many tens of thousands of dollars per kilogram to land hardware on - even with a 10fold price reduction, you're looking at big problems). And two, all its modifying is plagioclase and ti-rich theolitic basalt. And of course, tectonic modification can concentrate minerals. While there have been tectonics on the moon, they're very limited compared to those on Earth.

Now, this isn't to say that there's *nothing* interesting on the moon. The moon is rich in what's called "KREEP" - Potassium Rare-Earth Phosphorus. It can be found from space because it's also associated with higher concentrations of alpha emitters like uranium and thorium (although not anything one would consider "commercial" quantities). Don't get too excited over "rare earths", most are actually relatively common and not that valuable (although subject to big price swings - lanthanium for example took an excursion from about $8/kg to a peak of $180/kg in 2010, then back down again). However, rubidium is associated with KREEP. Rubidium sells for over $10k per kilogram, so if there were any spots where the Rb was further concentrated (in bulk it's only about 25ppm, far less than is found in potassium-mining concentrates on Earth for example), and if someone ever actually created a market for significant amounts of rubidium on Earth (there isn't one), that might be a possibility.

Compared to the moon, Venus looks to be a mineral treasure trove. For example, there's a common belief that even though we haven't landed on any yet, that there's widespread carbonatite volcanism at Venus. Carbonatite volcanism is associated with economically important deposits of phosphorus, niobium-tantalum, uranium, thorium, copper, iron, titanium, vanadium, barium, fluorine, zirconium, cobalt, hafnium, gold, silver, and other rare elements. It's a super-rare type of volcanism on Earth (with only one currently-active carbonatite volcano on the planet) but appears to probably be abundant on Venus. Venera 13 landed on bedrock composed of melanocratic alkaline gabbroids - while not to the extent of carbonatites, gabbro is also often associated with concentrations of many valuable minerals. There's still wide debate over the nature of the "high radar reflective" materials, but they appear to be something that has boiled out of the rocks and then "snowed" or otherwise deposited out at higher altitudes. This natural "refining" process could potentially deliver high concentrations of rare minerals to particular areas, or take away "waste" from minerals in other areas (just like acid leaching does on Earth, but even more pronounced). Speaking of acid leaching, Venus has no shortage of acidic compounds ;) There's also some evidence that Venus's atmosphere may have at various times in its history been cool enough to form a supercritical state; this would not only present a powerful force for erosion, but supercritical CO2 is an excellent solvent. Another interesting property of Venus is its full-crust overturn at several hundred million year intervals - again, very interesting potential as far as minerals go.

Comment Re: Umm (Score 1) 351

Voter turnout, for one. Fix may be too strong a word, I would go with address.

The problem is not the number of people that vote, it's the number of informed people that vote. And, by that, I don't mean educated people who have spent a long time studying the issues, I mean people who have a basic clue as to what their candidates views are (beyond 'wears a {red,blue} ribbon'). Forcing more people to turn up doesn't fix this, it can only be addressed by having an impartial media that's willing to cover the candidates public and private opinions without fear of reprisals.

Comment Re:Let's just not do it. (Score 1) 167

Windspeed is irrelevant turbulence is what matters; it does not seem to be significant at 52-56km altitude. While we know that lightning exists on Venus, it's only at about the rate that it exists on Earth, and seems to be biased toward particular locations and altitudes. Of course, we've studied the planet so little, who knows - it obviously takes prep work. A prep mission would basically be a long-term version of Vega, with solar panels for recharging rather than just running on battery power.

Comment Re:Let's just not do it. (Score 4, Insightful) 167

If we wanted to send humans anywhere that would pay the most benefit, I really think Venus (cloudtops) would be best. Venus is so under-studied that any mission (manned or otherwise) has the potential to yield huge scientific benefits, and the ability to real-time control probes exploring the surface (aka, where their time that they can spend near the surface is limited before they have to head up to re-chill their cooling reservoir and recharge their batteries, and you don't want the lag time of commands sent all the way from Earth) would be of significant benefit. And in terms of future mining potential, Venus probably has the most useful geology - the types of lava flows found by the Soviets, and the additional potential of carbonatites, combined with the "high radar reflective" precipitated minerals, all are very promising signs for enrichment of rare and economically valuable minerals. Phase-change balloons can descend to the surface and bring minerals up to the cloudtops, and are eminently achievable with current technology - hardly more complicated than the old Soviet Vega probes. Since you're floating, you can move anywhere on the planet in a relatively short period of time (due to superrotation, you really have no choice in the matter ;) ), so you're not limited to whatever resources happen to be close to your base. And the cloudtops are a very hospitable environment to humans - at 52-56km a person may even be able to step outside with nothing more than a mask on (oxygen provision and eye protection are a must, but the CO and SOx levels may be low enough to not be problematic to bare skin - the pressure and temperature are fine). The significant atmosphere overhead provides a good deal of radiation protection, even though there is no dynamo-driven magnetic field.

The moon is nearby and a conveniently low gravity well, but as far as minerals go, it's pretty boring - to the point that the best people have come up with is "helium 3 fuel" to power reactors which don't exist and which probably will never be an idea fusion fuel (if you can fuse it and can make an economic case for it, you can probably also fuse P-B which is much better and cheaper). And it will always suffer from "been there, done that" syndrome.

Comment Re:"..or what intermediate steps have to be taken. (Score 2) 167

Indeed :) Don't get me wrong, one can achieve great things through small steps but only if those steps are part of a long-term process planned out in advance with the ultimate goal in mind, and full committal from all interested parties (particularly those funding your endeavor) to follow it through to the end. Otherwise, you're just building castles in the sand to be washed away when the tide comes in.

Is the goal to go to Mars just to check off an entry on our species' bucket list, or is to move toward the the eventual colonization of the planet? Then we better have the whole colonization process down, down to what will lubricate the drive axles on the truck that hauls the fluorite ore from the mine on Arsinoes Chaos to the ball mill at Terra Meridiani, or how to make the replacement bolts for the elevation mounts for a sulfuric acid pipeline at the Becquerel chemical plant. That means in no way, shape, or form that nobody should do anything with Mars until you can launch a whole self-sustaining colony. But it's important to have planned out the whole programme in advance - knowing precisely what materials we're going to need, what parts, how quickly they'll be consumed, how much labor every component's operation and maintenance will take, what raw inputs you're going to need, where you can get them, etc, and ensuring that at no point are you consuming more of something than you can produce.

If you send things to Mars without doing this, you're just going to spend your billions of dollars launching dead-ends - made out of materials that it turns out that there's no practical way to make on the planet, or with processes under which particular steps work out to be impractical or impossible on Mars. Due to the tremendous expense to engineer and launch each piece of hardware to Mars, you want each piece to serve a critical role in your long-term goals. Sent a device to freeze carbon dioxide out of Mars's atmosphere to feed a greenhouse or bioreactor? That may sound great... up until the point that you discover that you also need nitrogen or argon collected from the atmosphere for other processes, and that your whole chiller system needs to be replaced with one that can handle lower temperatures. Sent a pipeline made out of polypropylene to carry some sort of fluid? Great, until you discover that you need to multi-use that pipeline and some of the chemicals you need to send aren't compatible with polypropylene, so you're just going to have to build a new one parallel to it. Etc.

NASA of course has no interest in actually planning things out all the way in advance. And never has.

Comment Re:Who are these people? (Score 5, Insightful) 381

socialist wealth redistribution

Often they just say 'wealth redistribution', which is the phrase that annoys me more than any other in political discussions. The people who say it are always implicitly in favour of wealth redistribution in one direction and often opposed to things that slow it, not just things that might reverse it. If I have $1m, and I invest it at a return 1% above the rate of inflation (not so hard when you have $1m), then I make $10K/year just from having money. If I have $10m and I make the same investments, then I'm making $100K/year, which is more than most people who work for a living, again just from starting with capital.

The average net worth of US senators in 2011 (I couldn't find newer figures) was $14m, for senators it was $7m (before anyone jumps in with partisan claims, the average for Republicans was higher in the Senate, but lower in the House). These people are earning more from their investments than most of their constituents. They're all - on both sides of the aisle - very much in favour of wealth redistribution, as long as that wealth keeps flowing to them.

Comment Interesting (Score 5, Interesting) 70

Kernel bypass plus zero copy are, of course, old-hat. Worked on such stuff at Lightfleet, back when it did this stuff called work. Infiniband and the RDMA Consortium had been working on it for longer yet.

What sort of performance increase can you achieve?

Well, Ethernet latencies tend to run into milliseconds for just the stack. Tens, if not hundreds, of milliseconds for anything real. Infiniband can achieve eight microsecond latencies. SPI can get down to two milliseconds.

So you can certainly achieve the sorts of latency improvements quoted. It's hard work, especially when operating purely in software, but it can actually be done. It's about bloody time, too. This stuff should have been standard in 2005, not 2015! Bloody slowpokes. Back in my day, we had to shovel our own packets! In the snow! Uphill! Both ways!

Comment Re:core point (Score 1) 186

Such a lifeform could easily engage in interstellar travel, even with the hundreds and thousands of years it takes.

Most sci-fi fans vastly underestimate the difficulty of even getting remotely close to the speed of light. The last, optimized, peer-reviewed design for a pure antimatter-driven ship that I saw - the highest performance you're going to get without beamed power, and beamed power suffers from range problems among others - was to reach about 0,4c. That's pure anitmatter, which vastly outperforms fusion and fission. Making antimatter inherently means turning mass to energy, wherein a very tiny fraction will condense out as antiprotons, which you can then trap. So you're taking E=mc^2, reversing it, and then taking only a tiny fraction of even that. Actually mass producing the vast amounts of antimatter needed for such starships would take a civilization advanced to Type 2 scale. It's nice to fantasize that the universe is full of Type 2 and Type 3 civilizations, but that's a huge thing to posit.

It's also easy to posit generation ships. But as the saying goes, shit happens. The longer you're in transit, the more likely that is to happen. Which means you have to make your ship vastly larger, to be increasingly redundant, parts in one part increasingly isolated from others, much larger crews than just the minimum skeleton crew needed to populate a planet, etc. Unless all you're sending are artificial wombs and eggs. But then you're back to my initial posit, that such information could be transmitted to an alien species directly at the speed of light.

Comment Re:Maybe (Score 4, Insightful) 414

Indeed. VW did very egregious cheating, deliberately detecting tests and then optimizing for them. It sounds like these others are not engaging a "test mode"; but have optimized themselves for conditions that are tested for (at the expense of power and fuel efficiency) while optimized themselves for power and fuel efficiency in conditions that aren't tested for. Not as egregious, but still clearly problematic. There's clearly gaping holes in the system.

It also puts to lie this massive increase in diesel cleanliness over the years. It's improved, no question, but not nearly as much as has been marketed, particularly in smaller, cheaper vehicles. The same old choice remains: you can get a ~15% increase in fuel efficiency by mass (~30% by volume), and thus ~15% reduction in CO2 emissions, by going with a diesel, but it'll come at the cost of a more expensive engine (has to be built stronger to handle the higher compression, all issues of additional pollution control systems aside) and will kick out more health-impacting pollutants. And it just comes down to chemistry: if you burn fuel in air at hotter temperatures and/or higher pressures, you favor the production of chemicals like NOx - high temperatures and pressures make nitrogen more reactive. And you're going to kick out more PM for similar reasons. The higher temperatures and pressures help with CO and unburned hydrocarbons (they favor more complete combustion), but the scale of the added NOx and PM problems are much greater.

Contrary to what they've been pretending, a major way that car manufacturers appear to have been reducing NOx emissions in diesels is simply by burning their fuel cooler / less efficiently in conditions that are being tested for, and hotter the rest of the time to keep their performance and efficiency numbers up.

You are in a maze of UUCP connections, all alike.