omenti

where nobody is average

The first military airplanes designed after WWII began to arrive in the late 1940s.  A number of these early jets were more complicated to fly and the number of incidents and accidents alarmed the military.  Incidents where something went wrong, but the pilot and aircraft came back safely, and accidents were more serious.  As the jets were mechanically more reliable than their piston powered WWII era cousins, it only seemed natural to blame pilot error.

 

A  few remarkable pilots would find themselves in a bad spot, but always manage to get themselves out of trouble - often saving the aircraft.  Chuck Yeager was the legendary master  and was sent to airbases to show pilots how to fly correctly.  But the fact was this was happening to very skilled pilots.  With pilot error and aircraft malfunction seen as less likely root causes, eventually cockpit design was questioned.

 

Military airplane cockpit measurements were based on an average of a few measurements of about a hundred airmen in the mid 1920s. Improved nutrition and larger pilots was suspected as changing the average, so a massive study was undertaken that took 140 measurements of nearly 4,100 pilots.  In theory this would lead to a better average cockpit.

 

Gilbert Daniels joined the medical division at Wright Patterson out of college and was one of the people tasked with making these measurements and coming up with averages.  It turned out he was biased.  In college he did some research trying to find an average hand size and found it impossible.  Sifting through the data he looked at ten measurements deemed most important for the cockpit and calculated an average range for each that included 30 percent of the measurements - a nice wide average.  The surprise was than none of the pilots fell within all ten of the wide averages.  Gilbert found if you picked any three of the ten, less than four percent of the pilots would be average.  No one was average.

 

It shouldn't have been a surprise. Women's clothing designers had known it for awhile - something attributed to women being "different."  Eventually the military believed Gilbert's work and mandated highly adjustable cockpits.  All new aircraft had to be adjustable for males in the 5 to 95 percentiles for each of about ten critical dimensions.  Airplane manufactures balked - "it can't be done",  but finally came around because .. well .. contracts.

 

The fifties saw more adjustability come to automotive interiors, but at a much slower and more incomplete pace than military aviation.  About ten years ago I found myself driving a friend's Japanese sports car on the Pacific Coast Highway.  A lovely car considered one of the best handling in the world, but I didn't fit - there was no way to adjust the seat or steering wheel enough.  I'm not particularly tall, but have short legs and a long torso.  I also have very long feet (in theory the right dimensions for a swimmer, but not my thing).  A few months later I was helping a friend move in a rented truck.  The same problem.  There weren't enough adjustments to prevent my feet from getting caught near the pedals.  And then there's automobile safety.  The instrumented dummies used in crash tests cover less than a quarter of adults bringing into question the tests themselves.  

 

And it's not just physical differences.  'What color is the dress?' became a popular question as people legitimately came to different conclusions.  Tonal language native speakers are much more likely than other populations to have "perfect pitch."  Some people are purely visual thinkers, but most are a mixture of audio and visual.  There are people with very poor stereo vision - I know one who is an animator.   Increasingly "on the spectrum" is a meaningless construct.  Our brains have so many differences - so many dimensions - that it's likely none of us are truly "normal."  This has become an issue in fMRI studies recently. For example studies showing differences between men and women are often in the noise and meaningless. The field will eventually get more rigor.  You really need to know what dimension you're measuring.

 

Finally there's neuroplasticity.  We know that kids undergo huge changes in neural connectivity as they grow and some areas of the brain aren't stable until the mid 20s.  (I have a neurological condition that is believed to have resulted from an incomplete severing of neural connections when I was a baby.  It isn't a big thing, but is different enough to be worthy of study).  One seen as stopping around 30, neuroplasticity is seen throughout life, albeit at different rates.  There are examples of dramatic repurposing of regions of the brain.  Helen Santoro's missing left temporal lobe is one of the more dramatic examples.

 

Differences are a feature.

 

 

 

clearing the air

a mini-post

A year ago I managed to help out getting a small grant from the state to build a number of Corsi-Rosenthal boxes with the help of two teachers (science and art) and about twenty high school kids.  It took a Saturday morning to build about eighty of the air cleaners.  All but two are still working and, even though the filters are visually ugly and dirty, they're working just as well.   I won't list all of the learnings - get in touch if you want to know more - but a big benefit besides cutting the viral load is dramatically cutting PM 2.5.  Kids and teachers report fewer allergy and allergy problems and toxic particulate from a nearby highway has been cut.  I suspect these would be great for fires and dusty areas (thinking Arizona and Salt Lake City).   In the past year more clever variants have appeared so check out YouTube if you're curious.  Oh - and filter prices drop if you buy 100 at a time:-)  The only downside was I never want to see duct tape again,

 

The motivation for the post was a fun discussion Andy Slavitt had with Richard Corsi and Jim Rosenthal on his In the Bubble Podcast.   Such a fantastic project for kids and adults!  (there are a number of commercials - Andy donates all profits to charities).

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couplings and friction

a quick minipost

 

Beginning physics students learn about simple coupled systems.  Things like pendulums with a weak spring between them and the like.  Next you look at somewhat more complex systems like a group of pendulums.  Put them on a solid surface and start them in different oscillations and they do their pendulum thing unaffected by their neighbors.  Now add a little communication by putting them on a floor that can transmit a bit of vibration, something interesting happens.

 

The coupling of systems is common in nature covering a very wide range of complexity inducing our brain.  Many of these systems are mathematically fascinating.  Turn up the amount of coupling and they behave as you might expect - at least to a point.  Then, as the comments of the system impose themselves on each other,  there's a dramatic change.  Sometimes these are good from our point of view and sometimes they're disasters.  The point of inflection is often marked by a perturbation - lightning strikes, hurricanes, pandemics, big lies.   The couplings are too strong to allow for anything but a change to a new state.

 

One feature of our society is an increased coupling of systems.  Social media and other targeted messaging, GPS, the Internet of Things, globalization, just in time everything, religion, democracy....  More systems are being connected and the amount of communication is increasing at a terrific rate. These couplings are often introduced to decrease cost and the "friction" parts of the system have with each other.   Many are  too complex to understand well, but the basic math of over coupled systems is clear - these systems can be very unstable. 

 

Building alternate pathways and redundancy into these systems is an answer, but that costs money and clever design.  Another alternative is reducing the coupling of certain important subsystems.  It's something I find myself paying more careful attention to.  Highly coupled or low-friction systems are usually brittle at some point.  I dislike the term "black swan" as real black swans (the bird) are not uncommon in nature.  But we continue to build serious and increasingly effective black swam bait...

 

 

 

31 is the new 35

Andrew Revkin and I had a brief exchange about the power of labels.  Both of us object to the phrase "climate emergency."  Even though it is an emergency that could escalate into an existential threat, people don't respond to labeling longer term threats as emergencies.  I've been suggesting we've entered an adaptation epoch.  Andrew, a much better communicator, is still searching.

 

The past two or three years have taught us short term temperature excursions can be dramatic.  Last year the Pacific Northwest recorded previously unheard of temperatures -  the highest in the area in at least 7,000 years and probably much longer.  This Spring it was South Asia.  Last week record heat came to England and parts of Europe.  These events are probably going to be more common and time goes on and greenhouse gas levels continue increasing. 

 

Wet bulb readings of 35°C (95°F at 100% humidity)  have long been considered unsurvivable.  A person in good physical shape would probably die in a few hours. Such events are extremely rare. Until the past decade they've only been recorded a few times and then only for an hour or so.  They're increasing in frequency and length - mostly in the Indian subcontinent.  Finding cooler spaces for people is a matter of life and death.  

 

It's become clear the 35° number was something of a guess.  Recent careful work shows it's more like 31° for young people in good physical shape.   Older and compromised people have lower limits.  The Tokyo Olympics had periods with wet-bulb temperatures in the upper twenties. Athletic performance during these periods was certainly compromised (I saw it happen to a friend). 

 

What can be done?  Cities suffer from heat island effects.  All of the asphalt and concrete increases the local daytime temperature and holds them at higher levels at night. (hot nights may be harder on the body than hot days).  Air conditioning helps, but it costs money and a power grid that not everyone has access to.  Reducing the amount of asphalt and concrete while planting trees can make a big difference.  It's a great justification for reducing the number of cars and roadways in cities (green spaces are a key motivating reason for the dramatic change currently underway in Paris).  Unfortunately green spaces are usually linked to wealth.  In many places racism and redlining have produced some of the worst heat islands.

 

There are other tricks that are easily implemented.  White paint  on roofs can make a difference. Paint that holds up to temperature and monsoons for the better part of a decade isn't cheap, but is becoming more popular.  In Western countries more reflective shingles are appearing. Some of these look fairly normal, but are highly reflective in the infrared and can make a difference in cooling bills. 

 

And you can send some of the excess heat directly to space.  

 

If you're in a very dry area go outside on a clear night and look up.  Feel the cooling on your face.  Now hold a piece of cardboard between your face and the stars.  You'll notice a warmer feeling.  Remove the cardboard and your face gets cooler. 

 

Your body glows - you've undoubtedly seen infrared photos and videos of people.  We radiate photons at a variety of wavelengths, but it peaks around 9.5 microns - about twenty times longer than visible light.  The  atmosphere is transparent to visible light and also from 8 to 13 microns.  Photons from our bodies can radiate to space.   Deep space is really cold (a bit over 2° above absolute zero) so your face is radiating some of it's heat directly to space - enough that you can feel the cooling.

 

Clever material engineering has produced materials that are good at absorbing the heat around them and then radiating it into space. It's enough to reduce cooling requirements - at least in places with very dry atmospheres.  There's still work lowering costs and making the surfaces last longer, but it's something else to try.

 

Back to the idea of an adaptation epoch. Many things will need to be tried and efforts will stretch for generations.  There's enormous opportunity.  It's both sad and dangerous there's so much 19^th century political inertia, but I'm optimistic more clever people, organizations and governments will finally emerge.  As a species we don't have a choice if we want to survive.

 

personal social media usage experimentation

minipost

 

A few years ago I found myself spending far too much time on Twitter .. generally an hour to an hour and a half a day.  Time I didn't have.   For a month I went cold turkey, but was frustrated as there were a few people I only interacted with on Twitter and, following about 50 people in one of my fields was a good way to learn about new discoveries and papers.  I decided to limit my time, aiming for a half hour a day in two or three sessions. One would be devoted to hunting for new papers and the rest of the time would be the water cooler.   It's been mostly successful - I'll admit to hours of serious doom scrolling around the January 2021 coup attempt, but generally I'm under my thirty minute a day limit.  (I also have one day a week when I try to cut Internet access completely).

 

With that background I was fascinated to come across a report on some real-world experimentation by a group of about sixty college undergrads - a group known for heavy social media use.   Matt Salganik taught Sociology 204: Social Networks at Princeton last Fall.  He posted a report on Princeton's Center for Information Technology Policy's Freedom to Tinker blog:  

 

Improving Your Relationship with Social Media May Call for a Targeted Approach

 

From the introduction:

 

What students did:

Our class had about 60 students, from a variety of years and majors, and like most Princeton students, many of them were heavy users of several social media platforms. Each of them designed their own treatment and selected an outcome of interest. For example, some students were interested in improving their sleep and others were interested in wasting less time. In addition to these student-specific outcomes, we also had all students track two common outcomes that have been studied by other researchers: subjective well-being and time use changes.

This process of self-experimentation is a bit different from what social scientists normally do. Typically, researchers standardize the treatment, randomly assign treatments to participants, and collect data so that we can compare across participants and treatment groups. In our class, however, each participant was a researcher and designed a unique treatment for themself. Even though this is not standard for research, self-experimentation can be a good way to learn. The treatments students developed fell into three main groups:

Targeted limitation (about 45%). Students in this group restricted – but did not eliminate – their social media use. For example, students in this group did things like stopping TikTok use after 8pm and avoiding the Instagram feed (but still using Instagram for messaging).

Targeted increase (about 15%). In class, we learned about some research that suggests people who use social media actively—rather than passively scrolling—see an improvement in their well-being. So some students committed to increasing their active engagement with social media. For example, students in this group did things like posting 3 times per day on Instagram or direct-messaging at least 3 friends.

Elimination (about 40%). Students in this group eliminated their social media use altogether on one or more apps. Students who designed these treatments did things like delete Instagram or TikTok from their phone, and some actively replaced their social media use with another activity they valued such as reading the news or spending time with friends.

 

It's worth reading and non-technical.  It also offers some advice and techniques in the assignments section if you want to try learning about  your own usage.  It seems clear that there's a broad spectrum of positive and negative use patterns. 

 

repairability

My Dad was a Ford man.  More specifically the Ford Falcon.  It was a simple compact car with a 170 cubic inch displacement straight six coupled to a three speed manual transmission.  It scored on the high end of the Mobil fuel economy test - about 19 miles per gallon when the average sedan was in the 12 to 14 range.   But what he really liked about it was how repairable it was.  Not only was it simple to work on, but most of his friends had cars with the same engine and transmission.  If something needed fixing we could usually do it ourselves using tools borrowed from one of his friends.  For more serious repairs there were specialized tools from Strobel's A to Z Rental, garages or (shudder) the Ford dealer.

 

The simplicity of cars of the day was balanced by crude manufacturing tolerances.  Pistons fit so poorly in the cylinders that the first 500 or 1000 miles were done with great care using an abrasive oil to polish the parts into shape.  It made a big difference in gas mileage and extending the life of the engine past 50,000 miles.  

 

The dual gas shocks of the 70s opened the market for better cars that used higher precision design and manufacturing processes.  That and the beginnings of cars that crumpled to absorb energy in crashes made simple repair much more difficult.  The amateur mechanic had largely vanished by the 80s.

 

Clothing and shoes were expensive back then.  Quality construction and repairability were important considerations while shopping.  Tailors and dress makers were common.  The same was true for appliances.  Vacuum cleaners, toasters and anything electronic could be repaired at home or the local repair shop. 

 

There are exceptions today .. Jheri makes her own clothing or buys high quality pieces with the intention of buying very little as she hopes each piece will last at least a decade.  She's abandoned fashion and has created a style very much her own.  I suspect some of you - Om for example - have a similar philosophy.    But while it can be done in clothing, it's next to impossible when electronics are involved.

 

By the time I was fourteen I had three or four black and white TVs.  None of them worked - watching TV wasn't interesting.  The tubes, capacitors, transformers, switches and so on..  now those were useful!  I designed and built a few radios and a stereo amplifier.   It was straightforward and the experience taught me a lot about electronics.  Now I look in a computer, TV or radio and see only massive integration.  It's still possible to build things, but design is much more difficult. Learning about circuit elements is probably better done with computer simulations.   

 

The right to repair movement has grown in recent years.  I welcome  it for some products, but given the tight integration of hardware and software  I worry it may not be as generally attractive as proponents claim.  

 

Smartphones are a case in point. Apple is infamous for discouraging third party repair.  You can order a kit from Ifixit to replace a screen, battery and some other parts.  It can work well if you have a bit of experience and Ifitit is upfront with the degree of difficultly. You lack the tools and technique to take apart, replace and reassemble the device to design specifications.  

 

My personal results are mixed.  I easily replaced the battery (twice!) on my first day, first generation iPod.  The battery and screen on my out of warranty iPhone 5 was a different matter.   After five hours of frustration I was left with an operating phone, but the case was fitting tightly and whatever waterproofness was gone.   The misaligned case also interfered with the physical buttons on the side.  I did get another year and a half from the phone though.   It could be worse.  I know someone who replaced the battery on an Android phone with an inexpensive battery from Amazon.  The phone got very hot during charging and caught on fire when he took it apart to pull the battery out.  It filled his place with acrid smoke, but fortunately only destroyed the phone and wastebasket

 

Apple is afraid of regulation so they offer repair kits for some of their devices.   The Verge documented a battery replacement.  You get a huge repair kit with a large hold on your credit card until Apple gets the kit back.  The process probably works well if you're skilled at working with small electronic devices, but this isn't for everyone. Given the cost of shipping I suspect Apple's losing money, but they're also trying to make a point of what it takes to do a high quality repair.  Of course a third party repair shop could buy the tools and perform quality repairs and I suspect that will happen.  Lower quality shops abound, but your phone or laptop may be a bit wonky afterwards.

 

We need to understand what's repairable, what's sort of repairable, and what's not.  Easy to repair smartphones have been offered but they're generally expensive and lacking in features.  I suspect smartphones, laptops and smartwatches are probably moving to a subscription model anyway.  Clothing and some appliances could made for longer lifetimes and repairability.  Then again convincing consumers and companies to move away from a consumption model is a huge, but very important, challenge. 

 

I've mentioned clothing, but should follow-up with other product areas where design for long life, repairability and upgrading is important. It's generally expensive, but in the long run can have advantages.  You may live in an example.

 

 

who are you going to call?

Drop two pieces of bread into the toaster and push the lever down.  You go about your business getting the rest of breakfast ready and then, after a few minutes, two pieces of toast pop up.  Have you ever thought about what's going on?

 

We usually think about the toaster receiving the bread and giving it back to us after a few minutes - electric heating somehow.  Someone from a few thousand years ago might wonder where the bread came from and what kind of magic transformed it into something similar but different after a few minutes.  He might wonder if the lever was some kind of prayer or incantation.  We can examine the process at a variety of levels and can find considerable depth.  We know the cord is plugged into a socket which has a path though a series of transformers and wires that usually lead to a generator that is turned by spinning a turbine with falling water or steam superheated by nuclear fission or the burning of fossil fuels.  When the switch goes on the load on the generators increases by a bit more than we're using.  The steps required advances small and large over the decades in science and technology.   For example getting the of generation and transmission of electricity to work efficiently depends on an understanding of Maxwell's equations and a fair amount of math.  

 

We don't think about these things because we trust them. There's a solid bedrock of reliable knowledge in much of our technology even though we're not one hundred percent sure of the science.  Our trust in science is nearly universal even though some of us chose to deny certain aspects.  Global warming deniers and flat earthers have no problem using the Internet - computer mediated communication built on silicon based semiconductor technology, fiber optics and much more.   Their mistrust is often based on something in their personal value system that to first order may seem orthogonal to the scientific arguments.

 

Not many people have a good handle on how science is done and how it progresses.  Many of us had to memorize the steps in "the scientific process" in elementary school, but it turns out it's messy and there's no formal process.  In college you may have come across Karl Popper's notion of falsifiability and Thomas Kuhn’s paradigm shifts. Both of these models have been shown to be wrong.  The view among many scientists and philosophers of science is science is more or less makeshift, but produces reliable knowledge and tends towards self-correction and reliable knowledge over time.

 

A few years ago a few lectures by Naomi Oreskes at Princeton gave me the basis of something I'm more comfortable with even though it's not complete. She argues reliable knowledge is based on five factors:  method, evidence,  consensus, values and humility.  I won't go into these as each is a deep subject, suffice it to say that the last three are deeply social - something many "hard" scientists tend to have a difficult time admitting.  Science is deeply collaborative and these social aspects often determine what is worked on as well as how it, and the people who did it, are perceived. 

 

Although most people trust much of science, personal and group values can get in the way of trusting certain aspects as well as certain scientists.  We've witnessed this up close with the pandemic, global warming and evolution.  I worry that many scientists have made a mistake by hiding their values (that's changing with some of us) as well as separating science and technology.  The separation of science and technology was value based and began to become dominant after WWII. Somehow science was to be the pure pursuit of nature even though it's linked to technology at the hip.  Often technologists are well versed in the science underlying their work and some venture into applied science.  Scientists, particularly experimentalists, are by necessity amateur technologists.  I've done some technology and have a bit of a feel for it, but I'm certainly not skilled - I do much better on the science side.  I'm in as much awe of great technologists as I am of great scientists. 

 

A final point.  Who should you trust to do science?  If the light in your house keep going out when you plug the toaster in, it probably makes sense to call a licensed electrician.  When a pipe in your house bursts spewing out gallons per minute, you call a licensed plumber and not an electrician or dentist. A trip to the dentist and not the Ghostbusters is in order when you hit a cherry pit in a piece of pie and a tooth falls out.  And when you're thinking of the long term - say your children's lives - listening to experts on global warming makes sense while listening to Mobil-Exxon or the Farmer's Almanac doesn't.  In each of these areas there are mostly good players and a few bad ones. You find the good ones from the consensus of their community. 

 

a thread of ev history

There's a nice vantage point in  Point Loma in San Diego with a monument to Juan Rodriguez Cabrillo.  In 1542 he made the first contact with the indigenous people of the area.  Not much happened, but sailing Northwards a few days later he noted smoke hanging over what is now Los Angeles.  Enough that he called one of the bays  Baya de los Fumos - Bay of the Smokes.

 

It's not clear what caused the smoke.  The Los Angeles region hosts three types of temperature inversions, each capable of trapping air masses close to the ground allowing smoke to build.  The region may have had one of the highest population density in North America in the 16th century, so it's possible the smoke was from thousands of fires - the region certainly held smoke in later centuries.  It's also possible there were large fires in the hillsides fanned by Santa Anna winds.

 

Before WWII Los Angeles, apart from areas around chemical plants, had fairly clear air most of the time.   That all changed after the war and by the fifties a thick brownish much often dropped visibility to a few blocks.  The brown smog was different from either smoke produced by wood fueled fires or the smogs coal burning was know for.

 

While the LA area was a natural environment for temperature inversions, it also hosted centers of intellectual curiosity.  A few years after the war Los Angeles decided to tackle the problem and created the first air pollution district in the country.  Arie Jan Haagen-Smit of Caltech managed to figure out what it was by 1950.  Sorting out how it was produced took a few more years.   He was able to show eighty percent came from  the automobile.

 

Caltech became a breading ground for ideas to deal with automotive smog.  By the mid 1960s Haagen-Smit and others were thinking about modern incarnations of electric cars. Wally Rippel was a student fascinated by the idea of electrifying transportation. His aha moment came when he showed electrifying the automotive fleet would only require a twenty percent increase in electricity generation.  (the number today is considerably less than ten percent). Wanting to move things along Rippel did what any Caltech student would do.  He challenged MIT to a race.

 

The Caltech team added over a ton of lead acid batteries to an old VW van for the Pasadena → Cambridge trip, while MIT converted a Corvair for their trip to Pasadena. MIT finished about a day and a half faster, but they broke down several times requiring towing more than once. The van, on the other hand, just motored through without incident and were declared winners.  

 

The 70s saw further development at several engineering schools. Recognizing batteries were heavy,  Caltech worked on early hybrid cars that would drive short distances on power from smaller battery packs before starting up a gasoline engine.  Along the way they develope regenerative braking to boost efficiency.  The first energy crises hammered home the idea that efficiency was important.  A Scientific American article appeared in 1973 telling the story of efficiency and declaring a person on a bicycle one of the most efficient forms of transportation in nature .. Steve Jobs later riffed on that calling personal computers bicycles for the mind.  An electric bike would be about twice as efficient as a human powered bike.  That led to work on motors and controllers. Unfortunately the American book disappeared and plans for a safe cycling infrastructure died.  Electric bikes would have to wait a few decades.

 

 

 

In the 80s Rippel was working with Paul MacCready's AeroVironment, something of a Caltech spinoff, on a specialized, almost anything goes, solar powered car for the five day World Solar Challenge race in Australia.  GM footed the bill for Sunraycer team and the car buried the competition.  GM engineering worked with them and the collaboration continued.  Learnings from the solar races went into new motor and controller designs as well as a recognition that aerodynamics were very important gave people the feeling something practical could be done.  Enthusiasm within GM's engineering community talked the company into building the EV1 - the first production modern electric car .  GM corporate didn't know what to do with it.. much has been written on how and why the project was killed after three years of production and extremely enthusiastic customers. Other than its batteries, the EV1 was more sophisticated than current electric cars.

 

Rippel and a few others from the EV1 experience founded AC Propulsion, building a demonstrator called the tzero.  More a proof of concept, it was sportscar designed to impress wealthy tech types defeating a stream of Ferraris and Porsches along the way. Martin Eberhard tried to convince them to take it to production, but the jump in scale was too much for them.  Instead he co-founded a company called Tesla well before Musk entered the scene.

 

Electric car history has many threads.  I'm familiar with this as I heard bits and pieces in school and through people I know.   The deeper story requires many more angles, but it's sticking how much can take place with just a few people.

 

I'm a believer in efficiency and infrastructure.  Moving towards safe active transport (walking, cycling and e-bikes) offers a much greater improvement over conventional electric cars.  (long story, willing to argue) 

 

A bit of early history. International Rectifier funded a solar car project in 1960.  Silicon solar cells were still very new and exotic.  IR provided solar cells to the space program, but wanted to grow a commercial market.  Doing the math they realized powering a home would be incredibly expensive, but a short range vehicle for city use might be practical earlier.  To make a statement they sent a solar panel to Charles Escoffery who converted a 1912 Baker Electric.  The world's first useable solar car.

Finally the clean air work starting at Caltech lead to catalytic convertors, reformulated gasoline and any number of environment regulation that have saved many lives.  That work was an innovation. 

 

the utility of a color-coded battery

There have been predictions of a hydrogen economy for decades.  At first glance it seems like the ideal fuel.  Its specific energy - how much energy you get from a kilogram - is three times higher than gasoline.  And the byproducts of combustion with oxygen are heat and water.   So why hasn't it happened?  It turns out you should think of hydrogen as more of a battery than a fuel.

 

Hydrogen is the most common element in the Universe and common on the surface of the Earth.  Unfortunately the kind we need, molecular hydrogen H₂ , is very rare.  The only practical way to get it is to use a lot of energy to break down more complex molecules.  Methane is the most common, but other hydrocarbons like coal are used.  The process uses more energy than burning hydrogen releases and usually produces a lot of carbon dioxide and other waste products.  

 

There are many industrial uses of hydrogen, but the fossil fuel industry has been interested in expanding to new markets like transportation and heating.  They have the knowhow - all they need to do is scale their operations.  In fact they've been lobbying governments since the 80s and billions of government money have been spent investigating a fossil fuel driven hydrogen economy.   A good fraction of the funding went into the development of practical automotive fuel cells  - more on that later.

 

In grade school you probably used a battery and two wires to make a simple electrolysis machine that broke water into hydrogen and oxygen gas.  These days the best electrolyzers are something over 70% efficient.  Sounds great but there's another problem.  The energy per unit volume (energy density) of hydrogen gas at atmospheric pressure is about 2,800 times lower than gasoline.  A gas tank for a car would be bus sized.  The trick is to compress or liquify it.   Compressed hydrogen has about one seventh the amount of energy as the same volume of gasoline.  Liquid hydrogen is closer to a third.  Larger, heavier and more expensive than gas tanks, but more practical than attaching a blimp to your car.

 

A hydrogen fuel cell uses hydrogen and oxygen to produce electricity and water. The efficiency of a fuel cell running an electric motor is higher than that of an internal combustion engine so the hydrogen tank is small enough to fit in a car.   Before you can fuel the car the hydrogen needs to be compressed or liquified, both of which take a lot of energy.   About a third of the energy produced as electricity where electrolysis takes place makes it to the tank.  From there you about half of that getting it though the fuel cells and motor to the wheels.   But with the right power source it can be carbon-free.  Unfortunately most of the hydrogen cars to date use a dirtier hydrogen.  And that brings up a marketing term:  the color of hydrogen.

 

Green hydrogen is produced by electrolysis using electricity from a zero carbon source.  Brown hydrogen is produced from methane and black hydrogen from coal (much of the industrial hydrogen in Germany and China is black) Both forms have serious production carbon emissions that, when used in a hydrogen car, emit more than a conventional car.  Blue hydrogen is an attempt to deal with brown and black carbon emission problem.  It't still produced from methane or coal, but the carbon is captured and stored.  I consider that something of a pipe dream, but Japan is interested in blue hydrogen produced in Australia.¹  

 

Hydrogen is frequently mentioned as the future for low carbon airplanes.  Liquid hydrogen would be necessary and huge tanks would be needed.  There are several designs on the drawing board that couild happen in  fifteen years using turbofans designed to burn hydrogen.  They'd still produce some pollution (NO_x) from the heat of combustion and the extra water vapor would leave thicker contrails.²

 

Recent geopolitical issues have raised the issue of using hydrogen to heat homes and businesses rather than natural gas.. after all .. there's a large and very expensive infrastructure in place already.  Countries like England are experimenting with hydrogen/natural gas mixtures. You can get away with as much as 20% hydrogen and use the same furnace burners and conventional pipe infrastructure. In the UK new furnaces will have to have a dual fuel mode - natural gas or hydrogen.   An infrastructure problem is it takes about three times as much energy to move equivalent amount of hydrogen as methane. Also current pipelines may be too brittle over time.  Hydrogen leaks much more easily than methane (which is already a problem) and hydrogen leakage is an indirect greenhouse gas.  There are a lot of potentially expensive questions to answer, so I wouldn't pencil this in as a slam dunk.  On top of it you need to produce about three times as much energy to heat a house with hydrogen as you would with just electricity.  Use a heat pump and electric heating looks even better.

 

Hydrogen could be used store power for the grid, but that gets into comparing many forms of energy storage, so not now.

 

My gut tells me hydrogen could see niche applications..  Long distance trucking if battery development plateaus  soon (I wouldn't bet on that, but I wouldn't want to be a truck manufacturer) and aviation in the long term (15 years at the earliest).  

 

But a final comment - if you have enough it will gravitationally collapse and fusion ignites - you have a star.  We happen to have one.  The trick is just one of collection.  So in that sense life on Earth and almost everything we do is part of an hydrogen economy, but the convertor is about 150 million kilometers away.

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¹ Japan is big on hydrogen and had originally envisioned scaling up nuclear power, but that pathdied with a tidal wave.)  At this point I think blue hydrogen has underpants gnome issues.

² Contrails appear to be serious global warming issues.   It's possible that leaving them at night doesn't make sense and flights may have to occur at lower altitudes - say 20,000 feet rather than over 30,000.  That would mean slower speeds which means propellers may be practical so liquid hydrogen powering fuel cells to run electric motors may make sense.

 

 

building blocks

Watching Apple's Mac Studio announcement yesterday took my mind to something Carl Sagan said in the Cosmos series.

The Mac Studio's underlying technology goes far beyond the many tens of thousands of person-hours Apple has invested.  The semiconductor industry that stands on the shoulders of Bell Laboratories back to the fundamental work of James Clerk Maxwell and before.  Apple and others are able to come up with advances that strike us as dramatic as they make an impact on our lives.  The impact of some innovations like the electric light, the telephone, the automobile, powered flight, radio, the atomic bomb and the Internet have changed how we see ourselves.   But take a look and they're all built on long chains of invention and innovation that are often forgotten.

 

This comes to mind with the horrors going on in Ukraine.  Russia has always had brilliant minds.  They've made stunning advances in physics and math, but they haven't been as successful as the West in building on that.  A good deal of their technology is derivative.  In the past 25 years this may be by design. Most of the export value comes from extraction - oil and other natural resources. These industries seem to fall under the direct control of Putin's friends.  More technical industries are still under oligarchs, but these aren't super high profit.  As long as the core players can control them, the real focus of the economy is what can be run by shear force and power rather than technology and sound business practices.  (note - this is speculation as I'm certainly not a Russian expert..  so take it with a grain of salt).  

 

High tech industry is required for the military and some consumer use.  Although that is supposed to be home-brew there is a lot of importing and rebranding. I've seen that in electronics used in physics experiments and am told is standard operating procedure.

 

So imagine you can't important and rebrand the CNC tools necessary to make jet engines.  Can you make the tools yourself. What if you can't even make precision bearings?  What if China doesn't allow electronics into the country (they probably will, but now they can be the Mafia dons)?  Sanctions can make a medium and longterm impact.  

 

You don't need to make your Apple pies from scratch - we have our universe - but few companies or countries have the capability to build objects of the modern world without technologies that exist outside.  All of these long threads few of us think about until they aren't available.  Think about all of those high value products waiting for fifty cent ICs that were designed twenty years ago...

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PS - I'd love a Mac Studio, but it's way beyond my budget.