Almost works

I’m looking for examples of chemical reactions, industrial processes, gadgets, that almost work. The laws of physics suggest that the thing is possible, but we haven’t found a way to do it, or maybe we can, but it’s uneconomical or painfully inefficient.  Or sometimes just a contrast between actual performance and the theoretical maximum.

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139 Responses to Almost works

  1. AppSocRes says:

    To date: nuclear fusion.

  2. Highlander says:

    Lawrence Livermore Lab has its laser based National Ignition fusion facility running at about the 1/3rd break even point if that counts as “almost.”

  3. Nick Rowe says:

    Cars powered by energy stored in rubber bands, coiled springs, compressed air, etc.?

  4. A good place to look is where VCs have thrown a lot of money but got nothing. VCs attempt bet on exactly this, technology that most think won’t work, but if it does gets 100x returns. So 80% of their bets fail, and in theory many failure should fall into that category.

    Current best example? bitcoin

    • gcochran9 says:

      re bitcoin: I’m sticking to the stroon standard.

    • Coagulopath says:

      Yes, business investments (kinda) follow a power law distribution. It’s common to make more money on your best performer than the rest your portfolio combined.

      I don’t know how bitcoin helps with anything.

      • ecgwine says:

        Cryptocurrency works just fine, technologically. Its application is a replacement for gold in a proposed return from fiat currency to a “gold standard”. The problem is that basing the world economy on a literal gold standard would make gold prohibitively expensive, and gold could never be used as a material again. There is no obvious material replacement for gold in this role, it would have to be a material more abundant than gold, with reasonably high cost in production or mining, and with no technological use. The solution of replacing the scarcity gold with cryptographically regulated scarcity is brilliant, and may in the long run still prove an extremely valuable innovation. Bitcoin is just the first proof of concept, I am sure that the market will become more relaxed with regard to the concept over the next couple of decades. It’s not supposed to be a get-rich-quick scheme, a few people getting rich quick is just a side-effect of paradigm shift, it’s not what drives the paradigm shifts.

        • Coagulopath says:

          It might work, but does it work better?

          Mastercard/Visa/Paypal let me send and receive money in a timely fashion, with a predictable transaction fee. If I make a mistake? No problem, I can reverse the transaction. I can’t do these things with Bitcoin. The amount of BTC banished to the Shadow Realm by a fat-fingered digit must be staggering.

          The advantage bitcoin seems to offer is “decentralisation”…except in practice, bitcoin has re-centralised around just five big mining pools, mostly located in China (where there’s cheap/free energy). At the buying side, supply is chokepointed by a couple of exchanges. Getting on these exchanges is hilarious. You’ve got to take a photograph of yourself, your passport, your driver’s license, the full lyrics to “Johnny Was A Racecar Driver”, your dog’s dick, etc, etc. They might as well be a regulatory body.

          The problem is that basing the world economy on a literal gold standard would make gold prohibitively expensive, and gold could never be used as a material again.

          I see a different problem: gold is deflationary.

          Why is “hide a pile of cash under the bed!” bad financial advice? Inflation. Over time your pile of cash will have less and less purchasing power. It’s better to spend it on goods that don’t depreciate, or invest it.

          But imagine if the opposite was true: the pile of cash under your bed gained value over time. You’d never spend it. You’d just leave it there, gathering dust, forever.

          That’s the issue with the gold standard. If there’s a limited amount of currency and an ever-growing economy, the currency will appreciate in value, and people will hoard it instead of spending it. This is an undesirable trait in a currency. You want money circulating, not sitting in a pile under the bed.

          We’re seeing this occur in cryptocurrencies, which are thinly traded and mostly used as an investment opportunity. Approximately nobody actually buys stuff with cryptocurrencies. The last time I did was in 2014, and I have a pretty big portfolio.

          The world is full of “crypto millionaires” who don’t have a pot to piss in. As soon as they sell their cryptos and actually make some money, they lose. Better to leave it under the bed.

  5. Highlander says:

    A quantum computer that can solve a problem faster than a classical computing device.

  6. Highlander says:

    Optical computers of various sorts.

  7. Highlander says:

    Tidal and/or ocean current powered electrical generation.

  8. Polymath says:

    I agree with all the previous examples. Let me suggest manned interplanetary spaceflight.

    Interstellar travel isn’t an “almost works”, it’s at the other end of the curve, “pipe dream”.

      • Highlander says:

        Orion out to the asteroid belt for exploration then another Dyson-esque technique of utilizing sunlight sail space freighters augmented with braking and/or boost light from solar powered lasers on the moon.

      • Leonard says:

        There’s a lot more to it than propulsion. You did specify “uneconomical” as a criterion. The problems with manned spaceflight are that it takes lots of mass to keep puny humans alive, and that there’s relatively little value in having men in space compared to robots. Arguably, also that we care about men’s lives. We could do a lot more if we didn’t need our astronauts to survive.

        Good luck to St. Musk, though. I think a Martian colony would be super cool.

      • James Fulford says:

        In Spider Robinson’s STARDANCE Trilogy, the viewpoint character says “That was what I had been afraid of. I’ve read that there are people who seriously propose propelling themselves into deep space by goosing themselves with hydrogen bombs—but you’ll never get me up in one of them things..”

  9. Highlander says:

    Hydrogen fuel “pumps” at every conventional filling station and truck stop preferably with the hydrogen derived from electrolysis of water powered by nuclear reactors.

  10. harpersnotes says:

    Electric bucket launchers for shooting non-human payloads into orbit. It’s an old idea that was batted around some in the 1980’s era, probably originally heard of by many through Heinlein’s Moon is a Harsh Mistress where they were used by the rebellion to pelt Earth from the Moon. (Coincidentally I was just recently throwing away a bunch of my old Claustrophobia zines which had several interesting-at-the-time articles on electric buckets.) Current demos of US Navy railgun ships are only up to a certain capacity, but their development has been driven by different considerations. (Search: US Navy railgun ships.) Apparently there were some demonstrations of the ships around July of last year. There’s a video from that time, but it only gets up to Mach 6, titled: Navy Railgun Successfully Fires Multi-Shot Salvos. (5406 mph, but to shoot up to orbit you need around 25,200, or 7 miles per second.) (As you are a physicist this might either pique your interest or bore you because you already know it’s limits all too well.)

    • harpersnotes says:

      (Self-assembling robots might work here. There are some interesting videos of those developments out there. Or giant spider webs as railgun targets with robots crawling along the strands catching the inert payloads as they arrive. Perhaps using electric decelerator tubes. Etc.)

    • ohwilleke says:

      Railguns are definitely on the almost list.

  11. Rashomon says:

    Fuel cells and a hydrogen economy. Metallic lithium batteries. Any high-energy battery that isn’t lithium-ion based. Theranos blood testing. Transverse flux motors. Autonomous driving. Useful general purpose robots (When was “Door into Summer” written?).
    Some of these will eventually work, even something slightly like what Theranos was promising. All have absorbed or are still absorbing large investments.

  12. Rashomon says:

    Metallic lithium batteries are perhaps the best example. They came before lithium-ion batteries, and their issue has always been dendrite growth eventually causing the cell to short. All kinds of coatings and designs have been tried to prevent it. Many auto companies are betting the problems will be solved in the next 5 to 7 years, as metallic lithium cells readily push energy density to 500 Wh/kg and should reduce energy-specific cell cost. But it only takes one dendrite . . .

  13. David Chamberlin says:

    Wars against drugs
    Absolute failure
    Great idea but now that we have passed the point of no return (we are over 51% dumbshits) democracy is more of a demolition derby between clown cars
    Prostitute game preserve
    Men love hunting, men love prostitutes, why not combine the two. Naked women with huge breast implants so they can’t get away from the fat old men chasing them.
    Legal automatic weapons
    Gee, what could ever go wrong with that idea
    Ornamental wildlife
    We love our ornamental flowers, bushes and trees, why not a backyard teeming with all kinds of critters we love at the zoo save the man eating carnivores. I don’t give a shit about a damn rose bush my backyard needs monkeys.

    • Highlander says:

      Automatic weapons are already legal in many states although the legal supply is finite plus they are prohibitively expensive to shoot very much.

    • Steve in Greensboro says:

      I was going to say democracy, too. Humans keep trying it and it keeps turning into shit. I’ve got another one.

      “Closing the educational achievement gap between racial and ethnic groups.”

      Mr and Mrs. Gates spent $1b to help close the gaps. It would have been more productive of societal good if they had given that money to me and I had spent it on hookers and booze.

      • ChrisA says:

        As far as I can see democratic countries are the nicest ones around. Why do you say that it has failed?

        • David Chamberlin says:

          Better to say Democracy almost works, which it does. Beating the crap out of the alternatives doesn’t mean it works well, Democracy almost works.

        • Recusant says:

          Because the culture and civilisation necessary for nice were there before they became democracies and are an absolute necessity for any idea of a democracy to have a chance.

        • SlushFundPuppie says:

          “As far as I can see democratic countries are the nicest ones around.”

          Liberian general election, 2017

          The President is elected using the two-round system,[6] whilst the 73 members of the House of Representatives are elected by first-past-the-post voting in single-member constituencies.

          Coalition for Democratic Change 596,037 38.4
          Unity Party 446,716 28.8
          Liberty Party 149,495 9.6
          Movement for Democracy and Reconstruction 127,666 8.2
          Alternative National Congress 112,067 7.2

          Elections in Haiti

          Elections in South Africa

          Soviet Union legislative election, 1937
          Communist Party of the Soviet Union 89,844,271 99.3

          • Thiago Ribeiro says:

            Yeah, the Soviet Union with an one-party regime and one candidate-elections is my favorite example of a democratic country… Oh, wait. It is not because I am not retarded.

    • Cloudswrest says:

      “Prostitute game preserve
      Men love hunting, men love prostitutes, why not combine the two. Naked women with huge breast implants so they can’t get away from the fat old men chasing them.”

      I guess you don’t recall “Hunting for Bambi.”

      The feminists were trolled hard!

      • David Chamberlin says:

        My paintball park would be called Crackland, four abandoned city blocks full of ghetto fun. You get a paint ball gun and a red or blue handkerchief to wrap around your head, the crips versus the bloods. Drug dealers and crack whores get free admission to Crackland so between taking pot shots at the other side one can experience the finer delights of inner city living. The problem with Prostitute Game Preserve is the women would have to have tits the size of beachballs or the fat old farts would never catch them. That problem could be solved if the old geezers shelled out big money for a weak paint ball gun that just hurt a little bit.

  14. Neocolonial says:

    Producing Steel without a blast furnace – the chemical reactions required occur at ~600C, while the industrial process we have functions at 1500. Can do it in the lab, but no alternate methodology has scaled.

  15. Je says:

    Many ideas:

    Lithium batteries are nearly ready to replace ICE engine tech and also daily grid storage. Trillion dollar market. Increasing density using Si annode or sulphur could provide a 2.5× boost in density or cost. It works but they expand too much and break the battery when cycled. Could be fixed with material science but only partially done by Tesla/panasonic.

    GaN (gallium nitride) still doesn’t quite make econ sense at higher voltages but is more practical at low voltages. It could replace bulky transformers and Si FETs. These also need to be integrated with some digital electronics to to drive them. $150B market.

    We need to increase the power/energy density of inductors to match capacitors and transistors. There are new ferrite materials, winding techniques, and using piezoelectric materials that might work. Probably worth $100B.

    Surface waves at semiconductor boundaries could potentially open up terraherz wave or many complex rf/optical/microelectronics markets with applications in sensors, comms, etc… $50B market

    • R. says:

      By.. nearly ready you mean they’d have to get 5x increased capacity and 1/5th the cost.

      • Je says:

        I’m hot sure we’re on same page. They are nearly ready now. Currently li ion batteries cost about 1.5x too much to replace ICE powertrain for a ~200 mile range vehicle. The total cost of ownership favors EVs at about $150/kwhr at the pack level at current oil prices. We’re at about $225/kwhr at pack level. Dropping about 20% a year.
        The density is fine right now for ICE. Look at Tesla cars… they are great except for price tag. This is why most car companies are now designing EVs in all product categories … not just “compliance” cars.

        Puddle jumper planes require 3x battery density to pencil out.

  16. Je says:

    Many ideas:

    Lithium batteries are nearly ready to replace ICE engine tech and also daily grid storage. Trillion dollar market. Increasing density using Si annode or sulphur could provide a 2.5× boost in density or cost. It works but they expand too much and break the battery when cycled. Could be fixed with material science but only partially done by Tesla/panasonic.

    GaN (gallium nitride) still doesn’t quite make econ sense at higher voltages but is more practical at low voltages. It could replace bulky transformers and Si FETs. These also need to be integrated with some digital electronics to to drive them. $150B market.

    We need to increase the power/energy density of inductors to match capacitors and transistors. There are new ferrite materials, winding techniques, and using piezoelectric materials that might work. Probably worth $100B.

    Surface waves at semiconductor boundaries could potentially open up terraherz wave or many complex rf/optical/microelectronics markets with applications in sensors, comms, etc… $50B market

  17. Anonymous says:

    flipping a bit without generating heat — oops! that doesn’t even work in theory! much less practice.

    • Esso says:

      As proponents of “reversible computing” have noted, you have to invoke the second law of thermodynamics to prove that. So there.

      This reminds me of another study approaching the impossible, impractical or oxymoronic, namely “reversible combustion engines”. The argument is that while practical internal combustion engines are quite well modeled as heat engines, they actually aren’t heat engines in the ideal sense. An ICE can have staged combustion and fuel reforming among other things. And who is to say it can’t be something like a fuel cell if it wants to, using chemical energy in a more reversible manner instead of just heating a working medium.

      Some of the proposed ideas might satisfy the criteria in OP, such as chemical looping combustion and noble gas engines.

  18. Highlander says:

    Recycling toxic waste including spent nuclear fuel back into the mantle by dumping it into subduction zones.

    • Graf von Jung says:

      Dumping nuclear waste (which is unspent fuel, really) is unnecessary Building new generation reactors that can use it as a far better solution. And theoretically can be done (but hasn’t been),

      • Highlander says:

        Nobody is going to be converting Fukushima dirt or those leaky tanks of God knows what at Hanford into anything. That stuff needs to be solidified/contained and dumped in the Marianas Trench.

  19. Martin L. says:


    • Highlander says:

      My Logitech solar powered bluetooth keyboard has worked continuously since 2011. It has an on/off switch but I’ve never bothered to use it. My Citizen dive watch has been running continuously even longer although I do have to set the date 5 times a year.

      • Martin L. says:

        I mean big-scale things like all of a full-sized house’s power needs, vehicles, etc. that solar proponents are constantly crowing are right around the corner and have been for twenty years.

    • Coagulopath says:

      My friend powers his house with solar panels, and even makes a bit of money selling electricity back to the grid. Though I don’t know what his power usage details are.

      • Spanky says:

        My Uncle in the UK does this, and he gets generous subsidies.
        However, the energy he dumps into the grid during peak sunlight, is less than the electricity he consumes in the evening. But it doesn’t matter, because the subsidies hand him a tidy little profit.

  20. sflicht says:

    Commercially viable perovskite solar cells. AFAIK these have been on the “cusp” of viability for 5-10 years now, but unless I’m out of date it seems like there’s still some missing ingredient to get these to be genuinely useful.

  21. DK says:

    Couple easy examples: Improving efficiency of CO2 fixation by mutagenesis of Rubisco. Transplanting bacterial nitrogen fixation machinery into plants. Both would be huge if succeeded. There are no obvious reasons why it cannot be done. Decades and enormous amount of effort and money went into both problems. Nothing much to report back so far.

    • ChrisA says:

      Yes this is the best one – there are numerous examples of where biology have developed room temperature reactions that we can only do at high pressure and temperature at scale, or very slowly in the lab. Another one to add to this list – direct conversion of methane to a liquid product at room temperature and pressures. There is a huge amount of associated methane gas flared in the oil industry as there is no economic way of converting the gas except at very large scales.

  22. l873198nwytg says:

    Muon-catalyzed D-T fusion nearly gets you to breakeven. It would, but for that pesky alpha-sticking problem. If only…

    Long carbon nanotubes, which have a few too many defects to be anything like as strong as predicted.

  23. ccscientist says:

    Mining the ocean floor. All sorts of educational methods (sound good but never improve student learning). Dietary cures for disease (too many to mention).

  24. catte says:

    The Wall.

  25. 2053 says:

    Smartass answer: Carnot engine.
    Slightly more serious answer: perfect vacuum.

  26. William O. B'Livion says:

    Polywell fusion?

  27. Jane Walerud says:

    Water filtration. At scale. It can’t cost too much energy. We need a reliable fresh water supply; rains are too unreliable. Supposedly graphene could work. But not yet.

    • ChrisA says:

      What do you mean by water filtration? It is a pretty trivial technical challenge to filter water and remove particulates, and it is very low energy. Do you mean desalination of water to produce fresh water? Actually desalination is done at very large scale (see Israel) and the costs are pretty low. Energy use is still about 3 times theoretical when I last looked at it but its not bad. The cost of supplying such water for any personal use (drinking, washing, cooking) is trivial – a few dollars a year. Where it gets expenses is if you try to have agriculture done in the traditional way using desalinated water. But you should not do that – there are large areas of the world that have plenty of water that doesn’t need to be desalinated where you can substantially increase agricultural production, or if you want to increase agricultural production in arid areas then there are low water use technologies such as drip irrigation (again used extensively in Israel) which can substantially reduce water use. Fact is, despite the reaching by environmental doomsters, there is no real issue with long term water supply.

      • In a sense, Israel is like small lab. Some people want all deserts to be converted.

        • Jaim Klein says:

          I think he meant water desalination. Current cost of production is 0.6 US dollar per cu m
          No one should go thirsty today. But only few societies are capable of operating a production and distribution network.

  28. GAGCAT says:

    Nanopore Sequencing
    Automatic Parallelization – or I’ll settle for effective abstractions that most programmers can use / reason about.

    • DK says:

      Nanopore sequencing is already perfectly functional:

      • GAGCAT says:

        Compared to early promises those products seem to meet the criteria of “uneconomical or painfully inefficient. Or sometimes just a contrast between actual performance and the theoretical maximum.”

        • DK says:

          Simply not true. There are many applications where nanopore thingies are preferable to the synthesis/fluorescence detection. Examples include much longer reads (critical for highly repetitive sequences), portability and essentially zero capex. Overall price per run is not that hugely different either. Illumina is much faster though.

          • GAGCAT says:

            I’ve been following nabopores since 2011 and to me the hype seems high compared to delivery.

            My sequencing facility was given a mini-Ion and haven’t figured out a use for it yet.

            We have a Pacbio Sequel for long reads and 5 Illumina machines (best is Novoseq) for short cheap reads.

            From memory there was some kind of catch with the Oxford Nanopore and you couldn’t publish benchmarks etc without their permission, which left a bad taste in my mouth.

            • DK says:

              “We have a Pacbio Sequel”
              Sorry to hear that. Pacbio will go the 454 and SOLiD way. A wonderful technology that is just not competitive enough with Illumina on large scale and with nanopores on a small scale. True enough, I wouldn’t want to sequence genomes with MinION but all kinds of microbiome detection or diagnostic applications are possible without sending samples to big centers that can afford Illumina.

  29. Doug says:

    Cryptocurrency. It’s truly brilliant, both as a technology and an incentive scheme.

    But, it just quite isn’t good enough to capture any significant amount of economic activity. As a medium of exchange, the transaction times are too long, the scalability’s too low, the fees are too high, particularly for small transactions. As a medium of storage the volatility with fiat currency is too much.

  30. FactNite says:

    True, IQ-boosting cognitive enhancement of the permanent variety, via either brain-zapping or some new supplement like NZT from Limitless. Even if it’s non-permanent, having a higher IQ for a few weeks or even for a few hours would be well worth the effort. This is already possible via embryo selection, and that will improve as more and more high-IQ genetic variants are discovered, but here I mean more like some way to enhance the intelligence of the already-living.

  31. dearieme says:

    There are devices that work at miserably low thermodynamic efficiencies but are perfectly practical, economic ways of doing jobs. Distillation columns are an example.

  32. John says:

    Space elevators.

  33. catte says:

    Breeding octupuses for intelligence

    • Liamtheobscure says:

      I, for one, welcome our cephalopod overlords.

    • David Chamberlin says:

      What is a genius octopus gonna do? We have a lab, we make an octopus intelligence test, we go through 10 generations of breeding the only the upper 1 percent of octopuses with each other. They are doing progressively better and better on the test. Finally we have bred the worlds smartest octopus. We look at each other through the aquarium glass. We try to communicate with him. He squirts ink at us and goes and hides under a rock.

    • ohwilleke says:

      The main issue with octopi intelligence is that their r style reproduction plan means that the vast majority die after a couple of years so they don’t have time to learn much with their already high IQ. Breed an octopus to have K style reproduction and you might very well end up with octopi overlords.

      • engleberg says:

        The main issue with octupi intelligence is that so many critters have evolved to eat them so they need an r style reproduction plan. Put them somewhere safe from sperm whales and watch them grow!

  34. Non-lethal weapons like tasers and pepper spray. They ALMOST work, stopping lots of people tased or sprayed, but some people are immune or fight through them. Then you may have to shoot them with a real gun, or if you don’t have one of those, die.

    Also, they’re only ALMOST non-lethal—some people insist on dying from them.

    • albatross says:

      This is a nice example of an almost technology–if the nonlethal weapons were a little better (same stopping power as a 9mm in street conditions, same lethality as a Taser), probably 99% of cops and armed security guards would be carrying stunners, and most of that 1000 or so people a year who get shot dead by the cops (mostly but not entirely criminals) would survive to go to trial.

      • Alex says:

        That sounds like we are increasing a problem we already have in abundance – the survivability of the criminal element which already has high birthrates. As opposed to the medieval period, when you get genetic pacification through high execution rates and low survivability for their families. People are already surviving drive by shootings more because of advanced medicine.

  35. another fred says:

    Artificial photosynthesis. Current methods are inefficient and consume expensive catalysts.

  36. George says:

    Large scale ocean water desalination is still energy intensive.

    Reclaiming minerals, and other recyclable materials from waste/wastewater as opposed to land filling or dilution -> ocean.

  37. albatross says:

    In cryptography, I can think of a couple ones:

    First, you can do key exchange (like with public key encryption or Diffie-Hellman) using only hash functions or block ciphers–Ralph Merkle figured this out in the 70s. The scheme works like this:

    a. I can make a kind of puzzle that encrypts a 128-bit AES key in a way that takes 2^{40} work to break. Making such a puzzle is easy, opening it to get the key out takes 2^{40} work.

    b. I make 2^{40} different puzzles, each with a different AES key, each requiring 2^{40} work to open.

    c. I send them all to you.

    d. You choose one at random and open it, requiring 2^{40} work.

    e. You send me a message with the 128-bit AES key you find inside that puzzle.

    f. I get an encrypted message. I have 2^{40} 128-bit AES keys I put in my puzzles, so I try them one by one till I find the one that decrypts your message.

    We’ve each done about 2^{40} work. An eavesdropper doesn’t know which puzzle to open, so he has to try about half of them until he finds the one you randomly picked. That’s 2^{39} * 2^{40} = 2^{79} work.

    In general, this scheme gives you an almost viable key exchange mechanism. For about 2^n work (and a lot of memory/communications overhead), you can get about 2^{2n} security. Which is never quite good enough to give you good security. And there’s apparently no way to do any better.

    Second, there’s a way to get digital signatures out of just hash functions. And it’s just on the other side of this “almost…” line–you can get hash-based digital signatures to work, and they’re practical enough, but they’re either huge and stateful or enormous and stateless. They just barely work. (The actual schemes people propose are super-complicated, because you have to pile on all the optimizations you can cleverly think up to get them to just barely be practical.)

  38. Eugine Nier says:

    Room temperature superconductors.

  39. Cryptographic election systems where a voter can prove they voted; and check their vote hasn’t been faked while not revealing choice they voted for.

    • Eugine Nier says:

      The biggest problem with cryptographic election systems is that voters can’t do public key cryptography in their heads.

      • albatross says:

        There are some pretty nice crypto/end-to-end voting systems, but they tend to be a little complicated to use. Punchscan and Pret-a-Voter are pretty nice, and Scantegrity is clever and plays well with existing election infrastructure. If you want to understand these schemes, start out by Googling for ThreeBallot–it uses no crypto but still gets the end-to-end property.

  40. Andrew S. Mooney says:

    Boron Fiber.
    Boron Fiber is basically the same as Carbon Fiber, it can be woven into cloth and used for laminates, infused with resins like Epoxy, machined without producing anything toxic or unpleasant, and can even be found in huge deposits in the western United States. It is even lighter than carbon fiber as an material and just as strong.

    It got used for one large application, once, the tailplanes upon the Grumman F-14 Tomcat fighter. It turns up occasionally in tennis rackets and basically nothing else.

    The problem with it is it’s production process. It requires a technique known as vapour deposition, onto a tungsten wire filament, like in a light bulb. This is bad enough, because the tungsten filament is heavy so it ruins the average density of the fiber, so it’s strength per unit of weight is lowered by having the filament running down it’s core. Then there is the energy cost, in that Boron has to be vapourised to deposit it. High temperatures = Not cheap. (Tungsten wire is needed as it is just about the only material that doesn’t melt at that temperature.)

    The reality though is that Carbon Fiber is better, not due to it’s own properties, but due to not needing this production process. It can be made cheaply (relatively) from crude oil, and carbon sources, which can be found everywhere, are greater in quantity. The initial process, pyrolysis of say oil or even bamboo to create graphite fibres is cheaper than the vapour deposition process, no filament is needed and the final steps like curing in an autoclave to compact laminates are identical.

    So there’s no point to using Boron, anywhere, for anything. The tiny amount of extra strength just isn’t worth the expense or the effort. When the Tomcat was being deisnged in the late sixties, Cabon Fiber and Boron were both still in their infancy as aerospace materials, and time carbon won due it being cheaper to specify for a small increase in overall weight.

    • Andrew S. Mooney says:

      Addendum (Sorry for earlier typing errors.)
      It wasn’t vapour deposition at first it was this: The original process used a chamber filled with boron trichloride and hydrogen, or Boron Hydride (B2H6) and elemental Chlorine.

      Pure evil as chemical combinations. The wire was then heated to 1000 degrees Celsius spooled through the liquids and Boron precipitated onto it’s surface. It was then wound up for onwards processing.

      Cost: $700 per Kilogram, in 1960’s money.

    • XRay says:

      I was once a technician/operater making boron filament wire, in 1968. Always wondered what it was being used for, so thanks. We would get small, about three inches, spools of tungsten wire, some running to 130,000 ft. and even greater on occasion. 440 volts @ 35 amps. So yes energy intensive.

  41. peterschaeffer says:

    Since the topic is things that “almost work”. How, about dinitro-acetylene. It should be the most powerful non-nuclear explosive possible (by some definitions) and it has no hydrogen (the combustion cloud should be invisible). Apparently, it hasn’t been successfully made so far. It appears that the DOD is trying. Note that octanitrocubane has been produced and is quite explosive.

  42. archandsuperior says:

    I’m late to this party, but I’m surprised that nobody has mentioned laser isotope enrichment. My understanding is that laser isotope enrichment of fissiles is clearly possible and very close to working. I don’t think there are any major snags except irregular funding. Funding is irregular because the technology is scary; about an order or two of magnitude more efficient than conventional enrichment.

    Magnetic refrigeration is another technology that only sort of works. Certain materials change specific heat capacity based on magnetic fields, but the effect is tiny for all known materials and a refrigerator built on this principle would be out-performed by thermocouple-based devices.

    I’m curious how close to a workable product Toyota was when they were investigating ceramic engine blocks in the 1970s. They put a lot of money into the project, and in theory the efficiency gains would be enormous. But nobody, to my knowledge, has actually marketed one.

    At least three companies have tried to make diesel-cycle wankel engines, and have gotten as far as prototypes. I’m not sure what went wrong, although the tip sealing would obviously be a bitch.

    • gcochran9 says:

      Laser Isotope separation does work: some guys in Australia finally got it working. They got permits for a separation facility in North Carolina. But uranium demand hasn’t picked up.

    • Esso says:

      Re ceramic engines: Partially stabilized zirconia and polycrystalline alumina have accelerated degradation modes in certain temperature/humidity/sliding regimens. In piston engines there’s always such a “sweet spot” somewhere. Maybe that’s one reason ceramics and ceramic coatings were abandoned?

      Some publicized problems are that heat transfer into the intake charge is much higher (conventional engines have a stagnant insulating layer of cool air on their cylinder surfaces) which results in charge dilution and related losses, and that lubrication of hot surfaces is very difficult. Also, higher temperatures mean more nitrogen oxides, which has become a pollutant of interest since.

      Still, there is no absolute reason why these problems could not be mitigated or circumvented and ceramic engines proven viable. In addition to somewhat higher thermal efficiency their exhaust is much more hot and thus more useful.

  43. jody says:

    almost a week late, but just saw this question and thought it was interesting. spent an hour thinking of a few. too much for one post. i’ll make a couple.

    chemistry stuff:
    fischer tropsch process. technically it works, but it’s not economical under current conditions. however, if the oil does run low before 2100, and alternatives are not really filling in the gap, then you can believe they’ll be converting coal into liquid hydrocarbons using a better version of this
    aluminum smelters was covered. currently they build some of the new ones near combined cycle natural gas plants, which helps with how power thirsty they are
    allam cycle power plant. will this work?
    mining sea water for uranium. this…kinda works

    vehicle stuff:
    cylinder deactivation. probably 40 years of work on this and it still doesn’t work. believe manufacturers will give up on this, in the advent of electric motors. nissan does now make variable compression pistons, though.
    fully electronic valve actuation/no camshaft engine. this sort of works. in koenigsegg’s lab. they call it freevalve
    replacing displacement with turbo chargers. currently underway due to CAFE. this…might work. have engineers worked out the issue that boost blows up engines and parts eventually?
    higher mileage tires. this works. to the tune of a 1 MPG improvement. at the expense of like, 50% of grip. so basically, there is no point to putting this rubber compound on your vehicles.
    CVTs. these work, but consumers reject them
    autonomous ground vehicles. almost there. not quite. they’ll get there, though. may depend on LIDAR development rather than better software

  44. benespen says:

    Bioremediation of groundwater contaminants. This comes in a couple of different varieties depending on what the contaminant is. Nitrates in groundwater cause blue babies for those who get their water from wells rather than a central distribution system, which can remove them before hand. Nitrates are just fertilizer, so you need plants to tap into the water table and extract them. This often works best with desert plants with long taproots, but the water table may not be at the right level, and the plants may not grow well in all climates/against all competitors.

    Organic solvents can sometimes be used as a carbon source by desperate starving bacteria. This is handy, as you just have to wait and the problem goes away. Unfortunately rate limited by the toxicity of the solvents to the bacteria and the need for the bacteria to be out of other options. If you have time, this could be better than the typical pump and treat we do now, but no one tries to do this on purpose. It was accidentally discovered during monitoring of contaminated well fields. Right now just a footnote in extremeophile microbiology.

  45. Anthony says:

    Supersonic transport. It’s physically possible, but it’s a money pit – not enough demand to make a profit.

  46. ProfTomBot says:

    Space elevator. It’s physically possible and could be engineered but too ridiculous and complicated to be actually attempted or made successful.

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