omenti

at the frontier of computational photography

A few of you are interested in computer-enhanced imaging.  The most exotic work often takes place in fundamental science where specialized instruments and techniques have to be built because nothing exists. I'd argue that particle physics and gravity wave telescope are part of computational photography, but some people demand something that registers as an image in our brain.  

 

If that's the case I'd claim the Event Horizon Telescope is one of the most exotic computational cameras in existence. It's approximately big - the diameter of the "lens" is about the size of the Earth.  Last week the EHT collaboration announced results of imaging Sagittarius A - the supermassive blackhole at the center of our own galaxy.  A few years ago the results of a much larger black hole in M87 were announced. The observation run was about a week with equal time look at the M87 BH and Sgr A* It turns out the computational techniques needed to sort out Sgr A* are were much more demanding and a few more years were required. 

 

I've talked about the EHT with some of you and written a bit, but it demands using hands, a blackboard and visual props.  Rather than link a potentially confusing explanation, I'll link to Derek Muller's piece (Veritasium - he's a fantastic science explainer). He also offers a quick visual explanation of what you're looking at.  You can't do this with just words and it's dangerously easy to get into deep water and get the audience lost.

 

 

Last month a week long observation at shorter wavelengths and a few extra telescopes was made.  Hopefully we'll see results sooner as techniques have been established.

 

ted lasso?

a minipost

I was listening to a panel discussion of elite sports psychologists, sports scientists, and a sports anthropologist when a question was posed:

 

Could a Ted Lasso exist?

 

If you haven't seen the show, Lasso is an American college football coach who is suddenly hired to coach an English Premier League team.  He had success in his D-II school, but it was clear he was hired to fail.  It turns out he didn't.

 

There was some laughter among audience members, but the panel members took it seriously.  It could work.  You'd need someone who was an incredible learner with success leading a team  of some kind.  Someone great at listening, observing and thinking.  They've need a Beard - a character who happens to be a serious soccer expert (among other things), but would never cut it as a coach.   Creating a bond with the players, listening to them, and be willing to experiment is key.  You'd also need management willing to put up with the time required to create a success.

 

The anthropologist noted some of these qualities are missing in NFL, NBA, MBA, and NHL coaching.  Coaches tend to be extremely confident of themselves and there is pressure to win.  Team culture can suffer and creativity is low compared with some other types of teams.  He pointed out some women's teams - particularly soccer and indoor volleyball -  are extremely innovative with positive team cultures well beyond any men's pro team he's seen. 

 

There was general agreement among those in the panel.  Coaching has a way to go in the big pro leagues, but the types of coaches selected are an issue.  A great women's soccer or indoor volleyball coach (several were mentioned) could be a Ted Lasso if they had a Beard at their side and the time to create change.   As an example a women's volleyball coach was mentioned.  Something of a household name in sports, he's as passionate figuring out how to coach a team of pre-teens as he is his countries national team.  He's experimenting and learning and might make a discovery with some twelve year old kids that works with his olympians.

 

It's culture all the way down at the top.  Maybe some of these multimillion dollar coaches aren't worth it, but it's unlikely the culture that selects them will change. 

 

It's an interesting game to think about the question in teams outside of sports.  

 

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. 

 

three dog nights and a changing world

My father never had the thermostat above 60°F and 55° was a more common setting,. At night it would be dropped to 50°.  The house was well insulated and the furnace didn't come on that often if it was above freezing.  During colder weather we spent most of our time in an insulated room in the basement.  We had a lot of sweaters, thick socks, and scarves.

 

Great Falls, Montana lies just East of the Rocky Mountains.  It can be much colder than its latitude suggests as cold arctic air can plunge Southward unimpeded along the Eastern slope of the Rockies.  Global warming has changed the climate a bit, but thirty years ago -40° (F or C) would happen every few years and long spells with high temperatures staying below 0°F are not uncommon these days.   It also happens to be very windy. The residents are became very good at adapting to the climate. 

 

Our house was small so I slept in a small travel trailer most of the time during my high school years. The only real insulation in the Winter was snow..  There were a lot of blankets, a down sleeping bag, a beagle and two silky terriers.  The dogs would make their own beds down to about 40°.  Below that they'd join me in the sleeping bag.   The only down side from these three dog nights was when the beagle had gas.  The sleeping arrangement was always toasty.

 

Another bit of information comes from David MacKay.  Staring in the mid 1960s someone at Cambridge interested in residential heat transport in homes put recording thermometers in a number of homes in town as well as a few other locations around England. The standard Winter daytime temperature was remarkably consistent - about 55° through the 70s.  By 2000 it had crept to 62°. Lower readings than Americans expect, but the Brits may dress more practically.    It would be interesting looking at the insulation value of standard wardrobes over time.  I suspect the emergence of low cost clothing is partly to blame.

 

Over-reliance on Russian natural gas is presenting an enormous problem in some European counties. Short term solutions other than conservation are non-existent, but conservation holds a lot of promise.  Heat people rather than spaces.  A few days ago Jheri wrote noting she's working on warm Winter clothing lines for German and Nordic markets on speculation that natural gas will be rationed for a few years.   The savings projections I've seen involve thermostat settings of 16°C (61°F) .. I know from experience you can go much lower and be perfectly comfortable.  (That said I don't know how some of the high school girls survived with miniskirts back in the day.)

 

In the medium term there are a number of things that can be done, but I struggle coming up with anything at the home level approaching the impact of serious conservation.  The same goes for petroleum usage. Infrastructure changes to encourage cycling can have a non-trivial impact.  Fortunately a few locations (Denmark and the Netherlands)  have made, or are making (Paris), great headway. 

 

The medium and long term will be dominated by power generation and distribution, but progress can and should be made with "smart" heating and cooling along with smart fabrics.   There's much to say about those areas, but for later.

 

Who knows.. maybe tech can be more meaningful than social media and blockchains..  

 

Who knows.

 

 

 

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.

__________

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.

 

 

what's in a name?

Surrounded by dramatic peaks on a narrow road etched into the side of the mountains you drop into forested area that continues into a string of foothills.  It's clear and you wish you were on your bike this time around.  The trees thin out and suddenly it's upon you.  You're at the summit of the last foothill and the expanse of the prairie opens up ahead.  Off in the distance is a short mountain range, but mostly it's prairie and you need to catch your breath.

 

Oceans and mountains have their appeal, but so does the prairie.  I suspect Montana Jeri and Alberta Jheri know this too. More than a few people from the area are taken by the outdoors. You find a number of artists, photographers, as well as people who are taken to learn about their surroundings.  I feel hard for the sky and have yet to recover.

 

The area is positioned such that auroras aren't uncommon during solar maximums.  Alberta and Saskatchewan have groups of serious amateur aurora watchers.   About ten years ago they realized something was different.  Something more frequent than garden variety auroras with a different color (they'd say colour) and shape.  Early spectrographic measurements revealed it was a thermal emission rather than the distinct colors of excited atoms dropping to lower energy levels.  

 

Serious work using satellites and the rich ground-based observations of the Canadian amateurs began around 2016.  It was real and not an aurora.  It needed a name.    One based on a children's movie turned out to be perfect.

 

The backronym Strong Thermal Emission Velocity Enhancement nicely suggests STEVE.

 

 

Much more is known now and the name remains.  The past week has been some beautiful displays along the Canadian Rockies.  I say them as a teenager and then again in my 30s, but didn't realize they weren't auroras.   Cheers to those curious enough to ask the questions.

 

great news! maybe the best model of how physics works is broken!

Then again it could be another false alarm.  Sometime about the W boson being too heavy.  I'll try and give a bit of background.

 

The best model of the universe - everything but gravity - is called the Standard Model. It unifies electro-magnetism, the weak force and the strong force - three of the four fundamental forces of Nature.¹   There are 17 fundamental particles (a physicist would say fields, but I'll use particles here).  The matter we see every day is built of a class of particles known as fermions.  Six quarks and six leptons. Protons and neutrons are made of two kinds of quarks and the electron is one of the leptons.  The remaining five are in a category known as bosons and are responsible for three of the four fundamental forces.  Gluons are associated with the strong force and bind quarks.  The weak force is carried by W and Z bosons and is responsible for radioactive decay and the process that makes the Sun shine.   The electromagnetic force is carried by the photon. Electricity, magnetism and the reason you don't fall through the floor.   And the Higgs boson gives the other particles mass (crudely speaking).  

 

All of this came together in the mid 70s with experiments confirming the Standard Model to higher and higher levels of confidence.  There were a few  suspicious corners, but none were showstoppers.  Until now. (maybe)

 

So what's not to love?

 

It's incomplete.  The matter I've described  - the stuff we're all made of and all of the exotic particles we're found - all of that represents a bit less than five percent of the mass-energy of the Universe.   Next to nothing is known about the remaining 95 percent!  That's a bit of a problem.  And no one has been found cleanly addresses all four forces.  

 

What scientists love to do is discover something.  Something completely new and out of the blue or perhaps overturning an accepted theory.²  That's what may have happened.  The W boson - a particle responsible for the weak force - is a very heavy and short-lived particle.  It's been carefully studied and a very careful experimental work at CERN gave us its mass.  This week the results of another very careful measurement using a different approach at FermiLab were announced.  Fermilab finds the mass is about a tenth of a percent higher.  Both measurements are so careful that the chance that that they're really the same is less than one part in thirty million..

 

It may be the CERN results are wrong and/or the Fermilab results are wrong.  Hundreds of people will be spending a lot of time reanalyzing data and checking that all of the steps along the way.  But maybe, just maybe there's new physics!  

 

Soon CERN will be taking data again after a three year long upgrade.  New measurements will be made that could settle the matter.  One of the explanations could be a fifth force of nature that is so subtle that it is only showing up here.  

 

There is real excitement although it will be several years before anything conclusive is known.  I have to add that my gut tells me there's probably a subtle bias, but my heart is hoping Fermilab is right.

 

But why?  I think there's something to fundamental curiosity.  The track record for generating useful spinoff is remarkable.  A few estimates place medical spinoff from high energy and nuclear physics in excess of twenty dollars for every dollar spent.  Of course there are issues with how long it takes, but some of you may owe your lives to these developments. 

__________

¹ So far no one has been able to cleanly add gravitation, but for calculations you usually consider it separately.  Something informally called Core Theory is the Standard Model with Gravitation tacked on separately.  

² In physics theory takes on a special meaning.  It's a hypothesis that has been rigorously tested to the point where it's accepted as the best description by the community.  It's a very high bar.

 

beyond 88

Yesterday Om pointed out that it was piano day - the 88th day of the year honoring the 88 keys of most pianos.  I read his post a day late, but there's still hope for another celebration with the same name. An obvious choice might involve the Bösendorfer grand where options include 92 and 97 keys in addition to the normal 88.  Music has been written for these beautiful instruments, but why stop there? 

 

Press a key on the piano and a hammer strikes one or more strings which begin to vibrate producing a sound.  The frequency of the vibration depends on the length of the string with longer strings vibrating at lower frequencies.¹  The left most key causes the longest string to oscillate 27 times per second - 27 Hertz (Hz) - while the right most key produces a 4,186 Hz frequency.  In between the keys are divided into 7 octaves, each composed of 12 keys.  Each octave doubles the frequency so the C above middle C has a frequency twice as high. The notes are evenly divided so each key has a frequency 2^1/12 times - just under six percent higher than the preceding key. 

 

Now we're ready.

 

Let's say you wanted a piano with the range of human hearing - usually given as 20 to 20,000 Hz in young children.   Going from 4,186 to 20,000 Hz, after a bit of arithmetic, requires 27 extra keys on the right.  Five keys on the left will get you to 20 Hz..   One hundred and twenty keys and some long arms would be sufficient to entertain young children to the limit of their range.

 

But what about dogs?  Canine hearing goes up to about 40,000 Hz.   All  we need to do is add an octave, or 12 keys, to cover their range.   Other mammals can hear even higher pitches.  Bats top out around 160,000 Hz so we add two more octaves giving us a 156 key instrument.  We don't have to go much higher as the atmosphere strongly attenuates higher frequencies. A bat can produce a very loud noise, but even their sensitive ears are only good for a 20 meter range.²

 

We've left out elephants which go down to about 12 Hz - that works out to 9 keys on the left. We've grown the beastmaster piano to 165 keys.   I won't cover whales because pianos don't work underwater. 

 

The game can go on.  There are any number of natural sounds of lower frequency (infrasound), but we'll leave it at that..  

 

Well - almost.  There are very faint sounds in the universe - ripples that move compress and expand space-time itself.  They come across a wide range of frequencies, but exquisitely sensitive instrumentation is required for some of the loudest - like colliding black holes where the energy that goes into the resulting gravity wave can be the equivalent of several solar masses.   It turns out the frequency of the first one detected was a chirp that went from about 35 Hz up to about 250 Hz (close to middle C).  You can play the signal as audio.

So much information there, but it may not be pleasing so let's end with one of the most demanding pieces for the human voice - in this case a coloratura soprano.  The Queen of the Night in Mozart’s  Die Zauberflöte. 

I'll leave you to find some good piano music today.  Perhaps Om's list is a place to start. 

_________

¹ It also depends on the mass of the string, its diameter and tension.  Additionally a rich set of other frequencies are produced giving the louder central frequency richness and character.  There's a good deal of art in the design and construction of a fine piano and none of the sound the same. 

² It's a feature.  Longer range would confuse them with signals from other bats, plus they tend to work a few meters from their prey.

 

the cost of knowledge is a great deal of ignorance

a mini-post

First a caveat - I have almost no background in the social sciences.

This week a few people have written about information overload. It’s certainly been with us since the beginning of the 16th century in the Western world and one can make arguments that extend further back. The rate of new knowledge, as opposed to raw information, has increased in many fields, doubling or more every decade and causing many fields to fission into new subfields. It’s a major cause of the imposter syndrome I feel when I’m trying to hack through a paper in low temperature physics for example … sixty years ago there wasn’t a problem thinking about both.

We deal with the information increase by specializing and creating what are often rich traditions. I’ve been able to carry on rich conversations with people where I have no Mandarin and the other person had almost no English by jotting abstractions and drawings of our shared tradition on a blackboard (slate blackboards are another tradition in my field) .

But these traditions blind us to the greater knowledge around us. .. It reminds me of the early experiment where you train a dog to respond to a bell. When you measure the brainwave of the dog you get a clear signal when the bell is rung. Now put a piece of juicy meat before the dog and ring the bell. The bell signal is nowhere to be found - it’s been overridden by the sight and/or the smell of the meat.

It’s funny - we don’t make progress without tradition, but it can also blind us to the greater world.. My belief is it’s important to communicate across the boundaries of the many traditions. I think this is an area where the arts are very powerful. We’re resorting to mechanisms we don’t have a real grasp on.. machine learning comes to mind.. to deal with some of this. There are many views on the subject, but I’m guessing it isn’t as useful as many suggest.

Finally there's an issue in traditions where knowledge doesn’t increase rapidly. How to be kind, how to be a good person, love, peace. Areas where people a long time ago had figured things out within the context of their tradition and arguably we haven’t made progress..

anyway .. just random thoughts on a rainy Spring evening. There are so many issues here that are interesting to think about.

Enjoy the Spring and listen to some music and enjoy some art. And some of you are creatives so create rather than sit back!

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A note on ignorance .. that's a complex subject in it's own right, but the title seems to fit.