omenti

a solar puzzle, 16 inch guns, and home repair

It looked awfully painful, but the burns didn't seem to bother him that much.  Ray plopped his tray down and the table and listened to catch the drift of of the lunchtime conversation.  Brookhaven was a wonderful place at the time.  Some of the best scientists in the world worked there and many were great at spending time with grad students and postdocs.

 

Ray Davis was already something of a legend in the late 70s.  He came to BNL in the early 50s to work on big problems.  Eventually he came to work on one that was fundamental - what are the mechanisms that power stars.  

 

Most of the energy on Earth originated in the Sun.  Your lunch today was probably sunlight that left reached our planet in the past year.  The gasoline in your car is older solar energy that has been stored for tens of millions of years.  The core mechanism that produces this sunlight turns out to be fascinating.  In the eighth grade you probably learned it is through nuclear fusion and in high school physics you may have done a simple mass to energy calculation.  The real mechanism turns out to be a tad more complicated that hydrogen fusing to helium.  There are several steps, but it can be roughly expressed as 

 

Four protons (hydrogen nuclei) are burned to a single helium nucleus, two positrons (positive electrons), two electron neutrinos and some energy.  The four hydrogens are a bit heavier than the helium nucleus and the positrons.  The mass difference is transformed into its energy equivalent and carried off in the form of a high energy photon called a gamma ray.  That energy eventually makes its way out of the Sun and radiates into space mostly in the form of visible light.  A tiny bit of what leaves the sun - about a ten billionth - makes its way to the Earth.  

 

Ray had a neat way to verify part of this - he could measure the number of neutrinos that left the Sun.

 

Hold up your thumb to the Sun.  Every second tens of billions of solar neutrinos zip through it.  They fill the space around us.  How hard can it be to measure them?

 

This turns out to be extremely tricky business requiring enormous care in experimental design and analysis.  Neutrinos were thought to be massless at the time and they interacted weakly with the forms of matter we're familiar with.  A solar neutrino striking the earth has a one in a thousand billion chance of interacting with anything.  Hold up your thumb and you would wait a century or so for anything to happen.

 

Ray's group used a 100,000 gallon tank of perchloroethylene - simple cleaning fluid which is chlorine rich).  It was buried almost a mile underground in an abandoned mine in South Dakota to act as shielding from other particle reactions.  If an electron neutrino with enough energy strikes a Chlorine atom, Argon-37 and an electron are produced.¹  

 

Every day about ten billion billion neutrinos would pass through Ray's tank and about two would react.

 

Every few weeks the tank was flushed and the Argon-37 was trapped in a charcoal filter and returned to BNL.  Ray happened to have access to a gun barrel from a 16 inch WWII battleship.  It was cut into a convenient eight foot, eight ton section that happened to make a dandy shield for low level radiation detection.²

 

Ray was very patient and very careful

 

The experiment went on for years and years - Ray and his group were seeing only about a third of what was expected.  Either the experiment or theory were wrong.  In cases like this you try to figure out just what went wrong, but the experiment was solid and the theory was very predictive and had become accepted.  Everyone knew Ray was missing something.

 

It turns out theory was wrong - or more correctly incomplete.  Twenty years later it was discovered neutrinos had a tiny mass.  They weren't pure electron neutrinos, but rather an admixture of states.  They would start out as electron neutrinos and during the journey to the Earth some would oscillate to the other state that was undetectable by Ray's apparatus.  

 

Oh - Ray's burns.  They were from a home repair incident.  They happened all the time.  He would do ordinary tasks to relax and think about other things.  There were times when his mind, which was working away at something, would shift to the problem and the real world would bang into him.  This certainly wasn't the only time and I'm afraid it happens to me more than I'd care to admit.

 

Last week I was walking down a street just before dawn.  It was amazingly beautiful with a thin cloud bank forming a few feet about the ground.  It wasn't more than ten feet thick.  I felt my mind wandering and suddenly I knew how to work a problem that  I had abandoned a month before.  I find putting problems aside that require creative energy to be extremely effective - assuming you have the raw material of richly diverse experiences and connections floating about.  Recently Jean and I were talking and she mentioned she sees a few levels to this and has relied on scheduling this offline creativity.  Mine isn't that polished, but I require spaces where I'm not focused on current problems if I want to be creative.  Thankfully my parents allowed me a great deal of freedom. Had I been scheduled to the point where I didn't boredom and freedom it is possible I would have been locked out of fields I love.

 

Neuroscience notes that creative bouts tend to occur when our heavily organizing frontal lobes lose a bit of control and free association in other parts of the brain lights up.  Being able to partly shut down the frontal lobes may be the key to creative thought, but you wouldn't want it to take place all the time.  A fascinating hypothesis that is currently being investigated is known as transient hypofrontality.  Some people are very good at it.  When very creative people are interviewed they all seem to have tricks to put themselves into this state where they can be highly creative.  There are lots of techniques including meditation, home repair, taking long walks in nature, alcohol (more than a few writers) and other drugs, and so on.⁴  You find what works for you.  I share walks in nature with Beethoven and Einstein although I'm not in their league.  Sketching is also very effective for me along with getting lost in music.  Whatever works and I'm far from an expert.   Creativity is much much deeper and richer than this, but it is a fascinating idea and these practices are very common in some groups.

 

There is something else that is beautiful about transient hypofrontality. Neuroanatomists note the wires that connect up different regions of our brain are myelinating as we develop. It peaks in our frontal lobes in our early 40s, and then begins to unwind and demyelinate, starting at the front of the brain and working backwards.³ Our frontal lobes become poorly at conducting signals, so our ability to move the connection processes to other areas of our brain may increase after the age of 45 or so.  Perhaps we can become more richly creative with age  - also if you are creative, it may stick around longer than some other processes.  I caution this is only a hypothesis at this point, but it may explain a lot and some of the initial experiments are promising.

 

In 2002 Ray Davis shared a baptism with Swedish holy water with two other physicists.  A richly deserved reward.

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¹ Nuclear physics involves alchemy - one element can be transmuted to another.  It turns out the detailed process that goes on in the Sun has a branch that produced neutrinos from the decay of Boron-8.  Those are the only neutrinos in the Brookhaven experiment with enough energy to convert Chlorine to Argon)

² Argon-37 is radioactive and has a half life of a bit more than a month.

³ Think of myelin as the insulation that shields our neural wiring.  It allows signals to transmit quickly and efficiently.  

⁴ Seymour Cray dug tunnels and built a boat every year.  The boats were burned at the end of the Summer to give reason to build a new one.  Of course finishing a boat was not the point of the work.

 

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Recipe corner

 

A simple avocado salad based on a recipe by Mark Bittman

 

Avocado Salad with Ginger Dressing.

Ingredients

 

° 85g rice vinegar

° 50g white granulated sugar

° 2 tbl minced peeled fresh ginger

° 2 avocados pitted peeled and seeded

° 75g chopped roaseted peanuts

° cilantro sprigs

 

Technique

 

° Put vinegar, suar, pinch of salt, and 2 tbl water into a small pan over medium heat  Cook until the sugar dissolves

° add ginger and continue cooking until the dressing thickens - about 5 or 6 minuts.

° Remove from heat cool and cover.  Let it chill at refrigerator temperatures at least an hour.

° Place a few cilantro sprigs on salad plates and overlap avocado sliceon top.  Drizzle wit the ginger dressing and garnish with peanuts and a bit of a finishing salt if you like.

 

probing your "failures" a bit more deeply

It is wonderful watching a little kid play with a magnet for the first time.  They have become so used to pushing or pulling something directly to get it to move that this motion at a distance breaks the model they have of the world and brings delight.

 

When people started to ask questions about what was happening, the answers brought fundamental changes to society.

 

You've probably done the experiment in grade school where you can change the direction a compass indicates by placing a current carrying wire next to it.  The other part of the experiment is equally beautiful.  You move a magnet next to a wire and cause a current to flow in the wire.  What is going on?

 

Before going a bit into that, take a look at Richard Feynman's high level comments on electricity.  He has a beautiful and delightful way of expressing himself

 

 

He mentioned Maxwell's equations as one of the most impactful discoveries anyone has made.  About the time the American Civil War started, Scottsman James Clerk Maxwell published a four part work called On Physical Lines of Force.¹ A few additional works were published and the summary of the work did not arrive right away, but we are left with four beautiful equations that are part of the foundation of our society....   If you did any technical work in college you are intimately familiar with them, but even if you didn't you may have seen them on a T-shirt.²

 

For those who aren't familiar with what they're saying, here is a summary in English²

 

° a magnet always has north and south poles

° the strength of an electric field depends on how much charge is in the vicinity

° an electric field is created by a changing magnetic field

° a magnetic field is created by either a current or a changing electric field

 

These are terrifically powerful and much of modern technology rests on electricity and magnetism.  The calculations for real world problems can be non-trivial, but it is all there - all that is required is a bit of curiosity and tenacity.

 

Consider the last two equations.  If you remove any charge you get an electric field is created by a changing magnetic field and a magnetic field is created by a changing electric field.  You can solve these together with a bit of math and the result is astonishing - you get a mutually sustaining electromagnetic field.  The changing electric field gives rise to an electric field which, in turn creates an electric field.  The energy oscillates between these two forms, which turn out to be at right angles to each other, as the wave merrily propagates through space perpendicular to both the electric and magnetic fields.  What is special is the speed of this wave is constant and just happens to be the speed of light.

About 25 years after the papers were published Heinrich Hertz showed that a spark could create such a wave.  Hertz didn't realize it at the time, but others showed that what he created was really a form of electromagnetic radiation - a certain frequency band of which we sense as visible light.  A major revolution in physics was underway, but none of the original people thought it would have practical value - little things like electric generators, motors, radio, television, computing and so on...

 

With this fundamental change came a major problem.  How was this electromagnetic wave propagating?  Waves traditionally required some medium to propagate though.  A material called the luminiferous aether was proposed.  A bizarre substance that filled the universe and had the property of being hugely stiffer than any known substance and very ephemeral - any normal substance could easily pass through it unimpeded.³

 

The whole notion of the aether seems silly today, but a fundamental change in how we thought about physics was required.  Somehow this bizarre substance was not as bizarre as what followed.  It turns out one of the puzzles it seemed to solve was how could light always travel at a fixed velocity.  It allowed the light to travel at a fixed velocity in it rather than worrying about the relative velocities of bodies that were moving at different rates.

 

One of Feynman's better observations was

First you guess. Don't laugh, this is the most important step. Then you compute the consequences. Compare the consequences to experience. If it disagrees with experience, the guess is wrong. In that simple statement is the key to science. It doesn't matter how beautiful your guess is or how smart you are or what your name is. If it disagrees with experience, it's wrong. That's all there is to it.

 

Albert Michelson and Edward Morley did the experiment with something called an interferometer - a device that is very sensitive to movement as well as changes in the speed of light in different directions.   They showed that the speed of light was constant in any direction relative to the moving Earth.⁴  

 

This was such a startling result they spent years working on improvements to the experiment to find any error on their part.  The results got better and better and with it the case for the luminiferous aether vanished and it became clear that electromagnetic waves could propagate though a vacuum^.5  It also gave a certain Swiss patent clerk who was doing amazing physics on the side reason for coming up with something he coined Special Relativity.

 

The Michelson-Morley experiment is one of the fundamental experiments in all of physics.  Its results were so unexpected that it was assumed to have been a failure, but careful probing of it by them and others as well as careful thought about what it really meant changed our concept of the universe on the scale that Galileo or Copernicus did.

 

Our imagination is stretched to the utmost, not, as in fiction, to imagine things which are not really there, but just to comprehend those things which are there.

 

This is the time of the year when I think of a few things I've done - some of them are predictions.  In retrospect our memory tends to paint a pretty picture of how we predicted the future.  I have been very lucky and have been in on some discoveries as well as inventions.  We had what appears to be a good track record, but a more careful examination reveals more than a few failures.

 

In the past decade I try to spend some serious time thinking about failed - or what appear to be failed - predictions mean.  I've come to place a huge value on my "failures" -what is really going on and what additional information did I need to discover there was a flaw.  

 

This process of learning has given me tools and methods to work on unexpected areas.  This generates serendipity and it exposes ignorance in a way that I can learn from many people and results including the failures of myself and others.

 

Aa observation - this process is similar to weather and climate.  Weather is a short term projection and is extremely difficult to get right.  The particulars are incurably difficult to understand.  Climate is a longer term feature  It is often much easier to predict the climate a decade out than the weather in two weeks.  The same is true for projecting technologies.  Rough directions are much easier than exact particulars.

 

Over the years I've been learning huge amounts from my failures.  The amount seems to increase with time, which seems like the proper direction.  

 

My New Year's wish to you is may you be as lucky with failure!

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¹ It is interesting to note that Charles Darwin's On the Origin of Species was published in late 1859.  It is difficult to think of any other discoveries in the last few hundred years that have brought more profound change to civilization than these two...

² Not as precise as it should be, but close enough.  It also turns out there are several equivalent ways to write down Maxwell's equations, so the T-shirts may look a bit different.

³ Upper limits to its mass were calculated - the density was smaller than a hundred trillion times lower than that of air.

⁴ More precisely they sent a limit - the Earth's velocity relative to the aether had to be less than a sixth the Earth's measured orbital velocity.

⁵ luminiferous aether would make a great song title or band name

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before the recipe, an image to fire your imagination

Allegory of Winter

Ambrogio Lorenzetti  c.1338-1340

 

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Recipe Corner 

 

A lassi as delicious as it is inauthentic

 

A Rich Seasonal Mango "Lassi"

 

Ingredients 

 

° a drinking cup 70% filled with a high quality eggnog at just above freezing (I like Ronnybrook Farms eggnog)

° a canned mango pulp at just a bit above freezing (I like Rellure Kesar Mango Pulp)

 

Technique

 

° lightly stir the mango pulp into the eggnog. Finally add a blob and artistically swirl it.

° top with toasted pistachios or sliced almonds (optional)

 

 

it isn't peeling onions...

Looking up at the sky is one of those pleasures that leads to the sort of questions kids ask.  What are clouds and why do they float?  Why are rain clouds so dark?  Why are the edges of clouds so well defined? What makes a sunrise or sunset red?  When did people start noticing the sky is blue?  Why is the sky blue?

 

The wonderful online comic strip xkcd reminded me of this the other day.  Kids pepper their parents with questions and this one is likely to come up.  The simple answer is given in the strip, but that doesn't get at what scattering is and why Rayleigh scattering works with air molecules.  Why it does and why it scatters as wavelength^-1/4 is something that usually happens in the first or second year of a college level physics course, but the follow-on question can stump the adult who hasn't considered a few more things.  It turns out our distorted perception of the world is centrally involved which leads to another herd of questions.¹

 

If perception is involved one begins to question if there are any cultural components to color perception.  It turns out there are.  Now one begins to question the nature of what color is.  Is it fundamental or is there a mapping between wavelength and what we perceive as - say - blue, red or yellow?²

 

childlike questions frequently aren't!

 

Some people use the analogy that science is like pealing an onion - you describe something but find, upon closer inspection, that there is a deeper explanation and beneath that yet another.    I'm afraid it doesn't work for me.  A better analogy is throwing a stone into a pond.  There is a splash and then a circular wave that expands outwards.  The wave laps up against things that you didn't know existed.  The edge of it can be thought of as the boundary between what we know and what we can know if we work at what has been uncovered.  We are newly ignorant and that is a wonderful thing.  The beauty is that our ignorance is expanding much more rapidly than what we know.  It is like diamond filled beaches that no one has seen are being constantly discovered.  Mining the old beaches can lead to questions that will lead you to entirely new shores.  That is why people do science - it isn't the discovery of an answer, but rather the discovery of a question.

 

Michael Faraday, in addition to being a brilliant physicist, was the Carl Sagan and Neil deGrasse Tyson of his day.  He had the habit of delivering public science lectures on subjects like candles.  Alan Alda (yes - that Alan Alda) is passionate about the communication of science and is an associate professor and one of the founders of the Center for Communicating Science at SUNY Stony Brook.  He felt there is a huge problem communicating science to the public and wanted to do something about it invoking Faraday as an inspiration.

 

Alda proposed a competition to simply describe how a flame works - a question that drove him when he was young.  There were hundreds of serious entries and they were judged for clarity by an army of volunteer 11 year olds.  

This year the challenge will be to explain time.  This may turn out to be interesting,  Science is pretty good at explaining how a flame works at a fundamental level and, for a gifted explainer, the gist of it can be communicated to an 11 year old. Time is deeper - it is fundamental at the level where we really don't know what it is.  That doesn't stop people from trying to learn about it by observation and experiment.  Physics is beginning to take cautious baby steps - time once was only for philosophers, but now some science is being done. Somehow the process of discovery needs to be communicated.  Figuring out how to communicate this to an 11 year old seems like an impossible task.  I'm very curious to see if there are some clever ways to communicate something basic about science.   At least it gets away from the fallacy that science is about assembling "facts"...

 

These things are fine and good, but there is still much to be discovered just staring at the sky.

 

If you are in a spectacularly dark area - the sort of place you sometimes get in places where large telescopes tend to get built - the Milky Way becomes impossibly bright and rich on moonless nights.  As your eyes adjust to the dark, you begin to notice a faint glow far from the times when you have remaining hints of sunrise or sunset.  The glow is strongest at the horizon and so faint it is colorless.  If you have some tools available you discover it is mostly green, but there are some other even fainter colors - far too weak for your cones to let your brain in on the show. This is the airglow.

 

Recently I came across this wonderful image taken from the International Space Station. It happens to be the airglow from space.  If you look very closely you'll see a faint bluish band that hugs the Earth.³  That happens to be the dense part of the atmosphere - the piece up to about four miles up that sustains life.  Most of our weather takes place here and we call it home and tend to think of it as large and expansive.  

 

It isn't and we need to take care of it...

 

But that aside the atmosphere continues for some distance.  The brightest region - the outer green band- is about 100 km above the surface.  This is where a bit of physics begins to unravel what is going on.   If you break light from this area into its spectral components, you get a few pronounced lines that were mostly described by atomic (not nuclear!) physics more than 100 years ago.  The bright green line has a wavelength of 558nm and is given off when atomic oxygen is struck by ultraviolet light.  It also has a fainter red line from a region at a higher altitude.  The yellow light is from sodium atoms and there is red light from excited OH radicals at somewhat lower altitudes.  But without getting deeply into spectroscopy and worrying about each line there are a few other questions that come up.

 

Why is it so bright?  Of course you have to consider the camera, but it turns out the airglow is about 1000 times bright on the side of the Earth facing the Sun (duh), but it is washed out during the day (duh again).  From orbit we can see a slice of the atmosphere that is still illuminated by the Sun while we are on Earth's dark side.  Nothing like an ideal location!

 

Why are the colors confined to such narrow bands?  This gets really interesting.  It turns out that bright green band comes from the atomic Oxygen excited state - it takes a very long time (by the standards of atomic physics) for this to happen - about a second.  At lower altitudes there are so many other air molecules that most of the just excited Oxygens get whacked by some other molecule that collides with them.  This process changes their energy and they usually don't give off that particular light.  As you go up in altitude the air becomes less dense and there is a point where the average collisions are rare enough - over a second between them - that the process can occur.  There are similar arguments for the other layers, but it is all about putting different bits of information together from fields that, on the surface, seem different.

 

It is common in science to find a new bit of ignorance in the ordinary world.  With the wonderful work going on at CERN it is easy to forget that quite a bit of real ignorance lurks on tabletops with very simple apparatus and, in some fields, there are wonders in a local pond (8 minute mp3). 

 

The whole trick is to be curious like an 11 year old and learn to ask questions and be open to something you don't expect.  I've had surprising and sometimes excellent results being curious and linking to outlying fields while doing work in fields far from my training and I suspect the same is true for of many of you.

 

Science has a formal method for doing this, but the same principles apply in many other fields.  Drilling in and asking questions, being open to answers you don't expect and even finding there are richer new questions, and connecting the dots with other fields that are very different from your own.

 

Oh - and if you have never seen a very dark sky you owe it to yourself to do so!  You can find some fairly dark areas in the lower 48 states - mostly in the desert Southwest, but there are a few good areas in other regions.  I'm about 250 miles from a pretty good area in Pennsylvania and have been known to drive for watching a meteor shower (not tonight though) or just getting a fix and remembering what a dark sky is like.

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¹ It turns out the answer has a couple of pieces.  The intensity of shortwave length visible light from the Sun decreases rapidly as wavelength decreases, but more important is perceptual.  We have three cones that register what we call color.  The cone associated with blue (the S cone) is very insensitive to shorter wavelengths.  We simple don't perceive most of the violet that is in the sky.

It turns out many birds and insects are sensitive into the ultraviolet.  They would see a much more violet sky - even a somewhat ultraviolet sky - than we do. 

It is wonderful when kids ask great followup questions.  This one is deep, but obvious in retrospect - if you see an eight year old do that you may want to encourage them to keep asking.

² It turns out color is very artificial - you can convince yourself of this easily by overlapping a very pure "red" light with a very pure "green" light.  Where they add we register something we call "yellow."  Neither of the original lights had any yellow wavelength in them.  It turns out to be a construction of your mind.

The wonderful NPR show Radio lab had a great segment on color perception that will leave you with some wonderful shores to explore from.

highly recommended!

³ Also look closely and you'll see the constellation Orion.

 

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Recipe Corner

 

Echoing the theme we end with peeling apples rather than onions.

 

This one is simple and good - maple roasted apples that almost give the flavor of an apple pie without the crust.  Great as a dessert by themselves - perhaps with a little topping like crushed walnuts.  I've tried it with a bit of cinnamon and nutmeg mixed in, but prefer them straight.  You'll want to use a rich grade B maple syrup (the grade has nothing to do with quality - grade B is darker and richer than A ..  which has its own delights).  

 

Feel free to scale the recipe - there won't be any problems as long as your tray is large enough.  It is terrific served over slightly softened vanilla ice cream or (better yet) a vanilla gelato (try Talenti)

 

Mapled Apples

 

Ingredients

 

° 4 large baking apples peeled and cored

° 100g high quality grade B maple syrup

° 55g butter (a half stick)

° pinch of salt

° 1/2 tsp ground cinnamon (optional)

° 1/4 tsp ground nutmeg (optional)

 

Technique

 

° preheat the oven to 375° F

° cut the apples into about a dozen equally sized wedges each

° melt the butter in a microwave oven in a bowl big enough to hold the apple slices

° mix the maple syrup, salt and optional spices in with the butter and toss in the apples and make sure they get coated with the mixture on both sides

° spread the pieces out on a greased cooking sheet and bake until soft and just caramelizing at the edges - about 40 minutes in my oven.  Turn them over about 20 minutes into the bake.

 

on a beach with the stars and the moon as company

A few days ago I was standing on a rocky Cape Cod beach at five am enjoying the starry sky.   Slowly the dawn began to approach from the East and a nearly full moon was setting in the West.  The sky was clear and stars down to about 4th magnitude were readily visible.  A darker night would have produced a larger display, but it is amazing how many stars you can see and, at the same time be able to see the moon.  

 

Sunrise was getting closer with the Eastern sky lighting up with dazzling oranges, yellow and reds.  

A rich experience like this makes you think about the wonderful dynamic range of some of our senses and the reason why our sensory responses are logarithmic.  

 

Astronomy is saddled with a bizarre and archaic brightness measurement (you find really strange historical measurements throughout science) called magnitudes. A star might have a brightness of magnitude 1 with dimmer objects receiving larger numbers. Historical conventions give a few starting points which are now abandoned as the scale is tied to other measurements.  The scale can be used for very bright objects like the Sun and moon. These bright objects have negative magnitudes as do the brightest stars and planets - Sirius, the brightest apparent star (brightness perceived by on Earth), is about  -1.5.

 

So what is the dynamic range of the human eye?  How much brighter is the brightest object you can see compared to the dimmest?

 

On a dark night with dark adapted eyes a person under 30 should easily see a 6.0 with some people in exceptionally clear areas going down to 7.0.  Using binoculars or a small telescope allows you to see much dimmer stars, but let's stick with the naked eye.

 

One of the first rigorous definition of magnitude had a difference of 100 in brightness represented by a change of 5 units of magnitude.  A first magnitude star is 100 times brighter than a sixth magnitude star.  This implies a one unit change of magnitude has a brightness change of the 5th root of 100 - a bit over 2.5 (2.512). 

A well placed full moon with a clear sky is -12.7 while the Sun blazes at -26.7 under ideal conditions.  That means the difference is about 2.512^{(-12.7 - (-26.7))} or 2.512¹⁴   If you work it out on your calculator you get the Sun being about 400,000 times brighter than the full moon.

Most of us can see a 6^th magnitude star on a really dark night, but someone with young eyes and great vision in a very dark area can go as low as 7^th magnitude.  Now the exponent is 7 - (-26.7)), so it is 2.512^33.7  This is approximately big - about 3x10¹³ or 30 thousand billion times!

 

Sweet, eh?   Your eyes are fantastic instruments!

 

You can perform a similar exercise with your hearing.  We can hear very loud (and damaging!) sounds.  Our perception of loudness is not linear, but is closer to the power of the sound raised to the one third power.  If you increase the sound level by a factor of ten you will perceive it is 10^1/3, or roughly two times, louder.  The units are decibels (dB) and the quietest sounds a human can detect are roughly 0 dB.¹  At the other end of the scale is pain, which is about 140 dB.  These are separated by 14 orders of magnitude in power!  - 10¹⁴ is an incredible range but, oddly, is close to the range of brightness the eye can handle.

 

In addition to our sensitivity to a range of brightness and acoustic levels, we are sensitive to different wavelengths of light and sound.²   Normal human vision is sensitive to electromagnetic radiation with wavelengths between about four tenths and seven tenths of a micron - about a hundredth the diameter of the thinnest blonde human hair.³

 

This three tenths of a micron range of wavelength gives us a tiny window into the electromagnetic spectrum.  Our brain interprets the shortest wavelengths we see as red - light with a somewhat longer wavelength is called infra-red and even longer wavelengths become microwave and then radio waves.  At the other end of the scale we have ultraviolet light - the stuff that causes sunburns.  As the wavelength decreases we move to X-rays and finally to gamma rays.  

 

The range of wavelength is amazing.  AM radio, by no means the longest radio waves we deal with, are as long as skyscrapers are tall.  FM radio is close to the height of a human, wifi waves are about the width of your hand and X-rays get down to atomic dimensions with Gamma-rays coming in even smaller.

 

Our eyes and ears are exquisite instruments and you may have the impression we have a good sense of our environment, but in reality we only are aware of a tiny window of what Nature has to offer.

 

But it is even worse than that.  Our eyes and ears do not deliver a perfect rendition of the information that falls on them.  It turns out a lot of filtering takes place - it has to as the amount of information around is is vastly larger than the path from our senses to our brain can handle.  We have a very effective filtering and compression - think of it as image and sound compression along with compressions of the other senses.  Much of this has a complex bias and the reality we sense is a construction of our brain.  Concepts like color, sound and music are completely manufactured and interesting quirks can be probed with carefully thought out experiments and illusions.⁴  

 

I don't mean to detract from the impressive instrumentation kit we are born with - it is mind wobbling beautiful - but we can get a much better sense of the real universe around us by building instruments and recording information with well understood biases.  Every time we come up with a new generation and type of instrument we open new richnesses in our understanding the Universe - we build this sort of apparatus to fuel and guarantee the inflation of our collective ignorance.  The telescope and microscope gave us enough of a change in perspective that we were able to fundamentally alter our views of the Universe as well as life itself.  Our window to the Universe has many more dimensions than just light and sound.  Consider the fact that our sense of time is highly constraining.  Now we can witness events that take millions of years as well as those that take place in a billionth of a billionth of a second.  We are even taking steps to understand things about our world and the Universe that are too large to appreciate - we are building computational macroscopes.  We are beginning to build synoptic instruments and techniques.

 

You can enjoy the richness of a slightly expanded window with a pair of binoculars. The clearest regions of the planet can rarely show more than 2,000 stars to someone with great vision.  A pair of 50mm binoculars extends your range down to about magnitude 10 on a wonderfully dark night.  Now you can see a few hundred thousand stars and you will be doing better than Galielo Galilei did when he rocked our notion of what the Universe is.  It is far and away the cheapest way to expand your window on the universe I know of. Try some time lapse photography with your digital camera and watch a cloud or a flower bloom.  Buy a filter and try some infrared photography.  

 

I won't dive in here, but our perceptual filtering is incredibly important.  I have spent a fair amount of time studying out of band communication - the part of human communication that is not carried by simple representations of voice and even video.  One of the things that is emerging is we, actually women, sense slight changes in shades of red very well and the amount of blood just under the skin - something that can depend strongly on health, nutrition and mood - is an important signal.  The problem is the video cameras and monitors we use are incapable of conveying this level of detail.  Audio is also poorly recorded and reconstructed and some important face to face elements are lost.  Our minds compensate of all of this, but mistakes are frequently made.

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¹ It is too easy to get very technical here as our ears respond different as a function of the frequency of the sound.  For example the quietest sounds most of us hear are around 3,000 Hz.  The response drops on either side.  At 10 kHz it is about 20 dB less - about 100 times, and at 100 Hz it is roughly 40 dB down - about 10,000 times.  Our response drops naturally and even dramatically with age and abuse.  Don't turn up that iPod!!

An interesting factoid is the the ear drum physically vibrates in response to the regular changes of air density that we interpret as sound.  At the quietest levels the membrane is moving roughly the diameter of a single molecule.  This is a rather exquisite instrument to say the least.

² I use the term "sound" loosely.  Technically our mind creates sound from the interpretation of variations of acoustic waves - regions of different pressures that travel as waves in the air at the speed of sound.  It is a definition, but it is possible to say that sound doesn't exist without an ear and a brain to interpret it as sound.  If you buy this a tree that falls unwitnessed in the woods has no sound - just acoustic waves that radiate out....

³ A micron is a millionth of a meter.  Fine blonde hairs are about 40 or 50 microns in diameter with thicker black hairs going up to about 200 microns.  The finest elements in an integrated circuit are a bit under two tenths of a micron - or about half the wavelength we call violet - the shortest wavelength light we can see.  

⁴ It is amusing that some video and audio purists prefer "unaltered" and analog signals when the senses produce and the brain processes very limited and abstract representations of reality.

 

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Recipe corner

 

First a quick non-recipe that is so good now that amazing apricots are available.  Cut perfect apricots in half (remove the pit of course:-) and dust with a bit of fresh lemon juice, lemon zest, vanilla bean sugar (I make this with old vanilla bean pods and regular white sugar).  Put on a baking sheet in a 350° or 375° oven and roast until the apricot flesh gets a bit soft.  The result can be pretty amazing.

 

And now an idea that struck.  I was looking at some cherry tomatoes and wondered how cherries would go with tomatoes.  Perhaps tart cherries with an heirloom tomato...?  So I decided to see if I could make a gazpacho based on some of the tart pie cherries I have and a tomato.  It was clear it needed cucumber, some garlic, stale bread, oil and so on - so here is the first try.

 

It is really delicious!!  I won't change it much the next time around.

 

Fruit "Gazpacho"

 

Ingredients

 

° 1 cup of pitted tart cherries

° a small piece of not terribly fresh whole wheat bread

° clove of garlic

° 1/2 garlic clove finely chopped

° a bit of olive oil or butter

° a half tomato peeled and chopped (I blanche them first to make the peeling easy)

° a small cucumber peeled and chopped

° 1/2 tsp chopped jalapeño

° 1 tbl vinegar (I used red wine)

° sea salt and ground pepper

°  50 or 60g or a couple of ounces of sour cream. (optional - it is plenty good as is, but this can add a bit)

 

Technique

 

° Remove the crust from the bread, rub the clove of garlic into the pores and fry the bread in a bit of olive oil or butter until it begins to crisp.  Alternatively you might start with garlic bread, which is what I was trying to simulate

° Combine the cherries, tomato, cucumber, jalapeño, vinegar, garlic fried bread, and garlic and blend with an immersion blender or put in a regular blender. Season to taste with salt and pepper.  Refrigerate

° To serve divide the gazpacho into bowls and add a dollop of the sour cream into each bowl.  You could top it with nice looking herb leaves or whatever.  I used a few blueberries and chopped pecans.

 

 

our sun is comparable to a lizard and beyond o,b,a,f,g,k,m ...

In the early 19^th century, as people began to understand the combustion of coal, people were scratching their heads about how the Sun worked. Coal was one of the most energy rich fuels and it was assumed the Sun must be fueled by something like that - finding oxygen somewhere to allow combustion. The thorny little problem was that the Sun would run out of fuel in one or two thousand years - an age in the ballpark of what biblical creationism calculated, but a number that didn't square with several million minimum age that the emerging science of geology required.

 

The German astrophysicist Hermann von Helmholtz theorized the Sun might be contracting at a slow rate and, the increasing pressure inside would increase the temperature and provide the necessary energy for the Sun to shine.  The shrinkage turned out to be about 130 feet per year, too small to measure, but as the real source of solar power - nuclear fusion - had not been discovered, it had to do for several decades.

 

I'll let you in on a curious bit of science to impress others with at cocktail parties. It turns out its power production density - the power produced by a volume of the stellar core where fusion occurs - is much lower than most people imagine.  A quick back of the envelope calculation suggests 275 watts/m³.  To put this in context a human's metabolism requires about 1,400 watts/m³

 

the Sun's power production density is closer to the metabolism of a lizard than that of you or me - let alone fossil fuel power plants or nuclear reactors.

 

what gives?

 

It turns out the fusion reactions in the Sun proceed at a very slow rate - slow enough that the Sun can last about ten billion years. It makes up for this slow rate by being enormous - the core is about one hundred thousand Earth volumes.

 

Much of what I do these days involves applied physics or trying to puzzle out the intersection of the social and technical worlds - both delightful areas that respond well to a physics background.  But astronomy is an old love that is impossible to leave behind and I get involved in a bit of research out of passion rather than occupation. For something over a year I've been thinking about mechanisms for the formation of brown dwarfs and a regular reader suggested I should write a bit.

 

You probably remember the mnemonic for stellar classification - oh be a fine girl kiss me...¹ O,B,F, G, K and M are labels that describe the temperature of the stellar surface. The important thing to remember is O is really hot and M is fairly cool. Other parts of the classification system include the luminosity of the star and a bit about its evolution - technically our Sun is a G2V star.²

 

Once a protostar grows to about 75 times the mass of Jupiter there is enough matter to fuse helium into hydrogen - the slow but steady process our Sun currently uses. About forty years ago it was postulated that very small and cold "stars" could exist. These "brown dwarfs" would be more massive than planets, but less than conventional stars. If a protostar is about 13 times the mass of Jupiter there is enough heat and pressure to allow deuterium to fuse. This process proceeds much more quickly and the little brown dwarf quickly runs out of fuel to burn. All it can do is radiate its residual heat into space getting colder, and colder and colder... The larger ones just take more time. At about 65 times the mass of Jupiter a brown dwarf can participate in another type of fusion - this process involves lithium into helium and doesn't last very long and produces an object with somewhat different chacteristics than its smaller brothers.³

 

The surface temperatures of a brown dwarf is so low that infrared telescopes are required - an area of enormous progress in orbiting and earth bound telescopes in the past twenty years. Thousands have been discovered and new categories have emerged expanding the classification system .. now, ranging from the hottest to the coldest, it is O, B, F, G,K,M, L, T, and Y.

 

My interest is in the coldest of the cold - the Y class brown dwarfs. These have surface temperatures less than 440° F.⁴ The record low temperature is held by a body with the strikingly unpoetic name WISEP J1828 + 2650 - its surface temperature is just 80° F - as I write it is 78° F in Basking Ridge - almost exactly the same. So cold no visible light is produced - just a little infrared radiation - and less per kilogram than your body produces (you are brighter!).

 

At these low temperatures it is possible for liquid water to exist - a bit colder and you there would be ice, but 1828 + 2650 is close to the current limits of detection. What I've been working on are possible water cycles in the atmosphere. A slightly warmer brown dwarf might have rather complex weather patterns where there water vapor rises in the atmosphere and condenses into liquid water where it rains to lower levels and vaporizes again. Other substances in the atmosphere - lithium and ammonia for example - interact with the process and the rotation of the dwarf adds to the fun. It gets really interesting when paired with a real star and there is significant energy flowing striking its surface. You get storm patterns - cyclones, spots and bands - just like Jupiter and Saturn and some similarities to the Earth.

 

and on a quiet morning walk before dawn your mind wanders and you wonder what type of life might evolve in that atmosphere

 

Every question you ask begets at least dozen more and you begin to curate the communal ignorance on the subject and learn from others who are doing the same thing.⁵

 

A few weeks ago I was talking with Juliette about how wonderful it is to be a tiny part of this Universe .. a 70 kg bag of mostly oxygen, carbon, hydrogen, nitrogen, calcium and phosphorous that has evolved to the point where it is - that I am - alive and able to ask questions about the Universe.

 

In a few very special places our Universe is self-aware.

 

It is a beautiful thing to realize that all of me save the hydrogen was forced in the cores of stars that exploded.⁶ Atoms through my body - throughout your body - are from several stars. Stars that exploded allowing life and us to eventually form. Such a powerful and delightful thought.

 

Ray Bradbury died earlier in the week. I read a lot of his stories as a teenager and recommend them to any teenager. This video seems to be a fitting memorial - he was asked to give a speech at JPL the evening before a spacecraft was to go into orbit around the planet. Enjoy!

 

Carl Sagan can be seem similing here - the first time I saw this clip was in a talk of his about a year before he died. Both of them would have approved of this cartoon. Phil Plait is an astronomer I know a bit. He was asked to speak at a high school science fair, but tore up his talk when he watched the TV new just before going to the fair. The reporter was spouting pseudoscience given "equal time" .. a bizarre concept as Nature is - well - Nature, and our crazy ideas often are wrong. Only those that describe Nature are acceptable to a scientist. He took out a notepad an wrote a short talk later sending it around and posting it to his blog. Then a few days ago an artist posted an illustrated version - click to embiggen. You can order a copy at zenpencils if you like.

 

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¹ Sadly that's all that most people remember as memorization was stressed more than learning the science in most classes. There are also a number of more objectionable mnemonics.

² It is amazing what can be gleaned from a tiny bit of starlight. This is directly from astrophysics, which emerged as a science around 1840. It was started by amateur, rather than professional astronomers as conventional astronomy had become associated with commerce (navigation) and had not tried the thing that was obvious to the physicist amateurs - namely to look at the spectrum of the starlight to deduce something much deeper. This was driven by the emerging technology of photography and an explosion of telescope construction - largely in the United States.

³ This sweeps a lot under the carpet - these processes are multi-step and figuring them out was a wonderful accomplishment of nuclear physics. To make fusion work on Earth so you get more power out of a reactor than you put in, it is necessary to run at extremely high temperatures and pressures - much higher than in the Sun's core. This is an incredible challenge and has been 30 to 50 years off since people first starting trying in the late 1940s. My view is we have a working fusion reactor that is only about five light minutes away - complete with shielding and it runs without any work on our part. All we have to do is catch and convert the radiation to useful work - a comparatively trivial technology by comparison.

⁴ Astrophysicists use a the absolute Kelvin temperature scale - Y class corresponds to 500° K

⁵ In past posts I've talked quite a bit on the importance of expanding ignorance as a scientific driver. Information is a byproduct, but the expansion of information is much smaller and far less interesting. I've been thinking about how to describe this without the baggage of the modern usage of ignorance ... I'm not there yet, but in science we talk about a communal ignorance - what the community finds new and unanswered - rather than common willful ignorance - the ugly ignorance that is the product of dogmatic systems.

⁶ The hydrogen came from the original formation - the Big Bang. Only about 15 pounds of me is hydrogen - the remaining 135 is the stuff of stars.

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no recipe this time - out of time

 

The great lizard photo is from www.wildretina.com

 

 

 

probing ignorance a bit more deeply...

I'm not happy with the way science is usually taught in secondary school.  It is rendered boring - memorize a number of "facts" and either replay them on a test or use some recalled formulae to plug in a few numbers to find an answer.  It completely misses the fun of science and also something rather fundamental about how new knowledge is found and why, at least to a scientist, answers and fact aren't the real product - even though they may be useful and advance knowledge.  It also creates a view of science that has opened a divide between scientists and non-scientists - something that in a society that depends so much on science and technology is a serious disconnect and perhaps a danger.

 

As it happens a beautifully cultivated ignorance and questions is more fundamental to the forward motion of science. I suspect applying some of the techniques may be very important to other fields where "out of the box" creative thinking is required and I sometimes rely on it in my consulting practice. The recent post on ignorance brought some email reaction, so it makes sense to wade in a bit deeper..

 

The general notion of what a scientist does is to collect data (information is a better term) by observing and manipulating bits of the natural world by doing something called experiment.  There is a methodology - the scientific method - which is based on observation, hypothesis, manipulation, further observation , a new hypothesis and so on...  There is a sense of order, but that turns out to be far from the truth.  You experiment to learn something - ideally to discover something.

 

Discover, dis - cover, is the act of revealing.  What is revealed can be very beautiful and it often becomes a "fact" in text books and teaching, but what many consider the end product of science are known to be unreliable to the scientist.  Nothing is safe - nothing is above question.  Not even something like the absolute speed limit of the speed of light.¹  Scientists don't know things absolutely, but rather report how well it is known.  Newtonian mechanics turn out to be incorrect - but at the scale where humans live and observe everyday things it is more than accurate enough that we still routinely use it as a "good enough" descriptive model.  We know where it begins to fall apart and have made other discoveries to more accurately describe those areas - special and general relativity for example.  

 

In the 19th century it was believed the universe was permeated with with a luminiferous ether to allow a substance through which light could propagate.  It was the wrong path and, in 1907, Albert Michelson became the first American physicist to be splashed with the Swedish holy water for failing to observe the ether in his extremely clever measurements of the speed of light. 

 

Think about it for awhile - Michelson got the Nobel Prize for an experiment that didn't work.

 

Some would later describe the ether as the black cat physicists had been theorizing about, experimenting and trying to measure in a pitch black room for decade.  Literally hundreds of approaches and many many scientist years of effort.  Michelson somehow found the light switch and it became clear the ether didn't exist to a rather high degree of accuracy.  The confusion that resulted led to an entirely new line of questioning - several doors to new rooms, all pitch black with their own black cats, appeared with the light provided by Michelson.  A patent clerk who went by the name of Albert was pushed to a line of novel questions that gave us a fundamentally new understanding of the universe.  And even better he opened the way for many rich new questions - questions that were beyond our imagination until we saw a bit of the nature of his black cat.  

 

Sure we had learned something, but  it gave us a new appreciation for how much more ignorant of the universe we really were.  

 

We keep discovering and adding to this area we call knowledge and people often make practical use of these discoveries, but the meaningful product of science is not facts or knowledge, but rather the expansion of an informed and cultivated ignorance.²  

 

One of my mathematical heroes is Kurt Gödel.  Mathematicians had a sense that everything - at least everything in mathematics - was comprehensible and could be explained with math itself.  Gottfried Leibniz, one of the inventors of the calculus, tried to construct an alphabet of human thoughts that would allow you to take combinations of thoughts and form any idea just as letters can make words and words can make sentences.  A few hundred years later David Hilbert made an attempt to similarly code knowledge. 

 

The impressive achievement of Gödel was to show that all of this was impossible.  Gödel was a shy and quirky person - hardly anyone's candidate for a revolutionary - but he is incompleteness theorems rocked mathematics and physics.  I can't give a rich general level discussion of what he did, but at its core he showed an consistent system in math (like the whole numbers and the operations - like addition, multiplication and so on) can't be complete and consistent.³ This may seem to be a depressing notion - finding a fundamental limit in mathematics, but rather it opened an incredibly rich source of new questions to Gödel and others.  It is fair to say that unknowability and incompleteness led to questions, reasoning and discoveries that have impressively benefited computer science - and to think that computer science is fundamentally based on absolute and complete logic:-)

 

This ignorance - the recognition that we really don't know something as deeply as we thought we did - is a fundamental driver of science.    The problem of the unknoweable isn't a real obstacle, but is really just a serious of paths to deeper understanding.  Also, to a scientist, the explosion of information isn't terribly important either - at least not at a fundamental level.  The rich sources of discovery are more dependent on new questions that arise from cultivated ignorance.  Questions are the goal of science - it just happens to generate results (with attached confidence levels!) that have historically advanced civilization and cultivated ignorance is a necessary component of making the process move.  

 

It is ignorance rather than data that moves science along.

 

A very import and somewhat subtle point of doing science is that scientists use ignorance to work and the management of this ignorance is incredibly important.  Sometimes it is called the taste in picking and progressing with problems.  It is often chaotic with communication and collaboration often being extremely important.  At the leading edge it is often cross disciplinary.  I have a tendency to not be able to describe exactly what I do.  This is really common among scientists and the area they are currently working in is often shifting dynamically.  It is messy and may even seem inefficient, but it is a proven path to real discovery.

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¹ Which is why the recent neutrino experiment got so much attention.  People have been testing the limit for over a century and so far all of the results that suggest it can be violated, including the most recent, have turned out to be so flawed as to be invalid.  A good deal of pseudo-science is based on experimental "results" that are incorrect - they are often trivial, but sold to non-scientists as something absolute.

² The time gap between discovery and practical use can be very long.  Faraday thought his early work with electricity and magnetism would have no practical use. A practical use for general relativity seemed a crazy notion for fifty years, but it turns out to be a critical component of making the global positioning system work as accurately as it does.

³ Consistency is the characteristic that a system's rules will not  result in self contradictory statements.  Think of science fiction as a rich source of counter examples - when Captain Kirk defeats machine logic with simple logic puzzles.  Take a card and write "the other side of this card is true" on one side and "the statement on the other side of this card is false" and think about it for awhile:-)

At least two readers of this blog are mathematicians and my appologizes for the very rough high-level treatment of something that is very rich and deep.  If you are a student just study the work!  If you aren't technical I strongly recommend Rebecca Goldstein's book on the subject.

 

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Maple pecan pie - really good with vanilla ice cream or gelato!

 

Ingredients

° 1 unbaked pie shell

° 215 grams/2 cups pecans (coarsely chopped)

° 55 grams/¼ cup dark brown sugar

° 25 grams/¼ cup tapioca starch

° 4.5 grams/ ¾ teaspoon kosher salt

° 240 grams/1 cup grade B maple syrup. Grade A or "fancy" may not be strong enough

° 60 grams/¼ cup heavy cream

° 4 grams/1 teaspoon vanilla

° 2 large eggs

 

Technique

° Preheat the oven to 425°F

° Place the chopped pecans in the unbaked pie shell. Whisk together the sugar, tapioca starch and salt in a medium sized bowl. Whisk in the maple syrup, cream and vanilla. Whisk in the eggs. Pour over the pecans.

°  Bake for 20 minutes and then turn the heat down to 350°F without opening the oven. Bake for an additional 30 minutes. Let pie cool at room temperature for at least 30 minutes before serving.

 

 

a pre-review

Jon Gertner's new book on Bell Labs has just been published and a few people have written to ask what I think about it.  I haven't read it yet, but am very curious as I was part of that organization from the end of its golden years through its demise.  It was a unique and amazing place - a fundamentally different approach to "innovation" than what is common today.  It isn't clear to me which approaches are better or worse - the old Bell Labs approach doesn't square with how companies work these days.

 

The old AT&T was a regulated monopoly divestiture in 1984.  A few percent of its income was channeled into running the labs - known as the Bell Telephone Laboratories and, through a series of regulatory consent decrees - funding was incredibly stable and sufficient to insure very long term research and development projects.  After a decree in 1956, inventions were licensed under very liberal terms to the rest of the nation and the Labs had become something of a national laboratory.  

 

I won't go into the history of the place and will be interested to see how it is charted in Gertner's book, but the core DNA of the place needs to be explained.

 

Innovation had a very specific meaning.  It didn't mean invention or discovery, but rather was discovery taken through stages of development and finally implemented at a scale that would change society.  

 

The Labs was primarily advanced and applied development with a core basic research arm (area 10 - later renamed area 11 about the time I joined it).  Fundamental researchers were presented with an amazing array from curious problems.  The notion was not the standard approach of engineering where you attack a problem by tallying your resources and try to build an optimal result, but rather something a bit more zen.

 

In the research unit you defined and attacked problems by looking for the unknown and then trying to understand as much as your could about it.  You had to go deeply into uncharted territory not knowing if your efforts would pay off or if you had the right intellectual tools for the job.

 

This approach - solving a jigsaw puzzle not by identifying your pieces and putting them together, but rather looking for the missing pieces and trying to solve a puzzle by understanding what was missing - required a multidisciplinary approach.  It is close to the approach of physics and basic research had a high percentage of Ph.D. physicists.  Really good ones.  Their specialties were not as important a their taste in problem solving.  I was an experimental particle physicist.  Bell Labs never dabbled in particle physics, but that was "the right stuff" and they saw an immediate match.

 

We worked with computer scientists, mathematicians, statisticians, mechanical engineers, electrical engineers, opticians, chemists, acoustics experts, material scientists, psychologists, neurologists, biologists, musicians and artists to name a few backgrounds.  The central laboratory at Murray Hill, New Jersey was built around a five story corridor a quarter mile long with a sometimes maze-like structure of smaller buildings.  Going to lunch or visiting someone else's lab would force interaction with others. It was said a researcher going to lunch was like a magnet rolling by iron filings.  It was a brilliant architecture and aspects of it have been duplicated elsewhere.¹

 

Some of the projects had very long horizons - digital communications took about four decades and thousands of researchers years of effort.  This type of time frame is only seen universities and national laboratories these days and is rarely directly coupled efficiently with commercial development.

 

But the next step in innovation - and one where the majority of Bell Labs people worked - was development research and engineering.  This is enormously difficult to get right. Most of the projects were defined by either Bell Labs management based on needs of the Bell System or by the government for national defense.  Many were difficult projects that advanced the state of the art by an order of magnitude and this was something of a model for DARPA, which came about in the 1950s with a clearer focus on military needs.

 

As the applied research and development proceeded it was productized and turned over to Western Electric - the manufacturing arm.  People in the various units spent time with each other.  Small branch development labs were built into Western Electric factories and the development folks often worked directly on the lines to understand the problems.  

 

The approach wasn't as clean as I describe it and there were tensions that had to be dealt with, but it was an innovation engine that changed the world.  It even paid a lot of attention to education creating everything from science and engineering ciricula to identifying promising students - mentoring them and getting them through their Ph.D.s in the best universities at no expense.

 

A very different approach than what is used, and perhaps needed, today.  The model today has universities and national labs doing the basic work with companies mostly engaged in short term development - real corporate research is not common.  Even long term development is rare^.2  True corporate research is mostly dead as is an integrated multi-disciplinary approach.  

 

Companies identify the pieces of the puzzle they have and try to build something optimal rather than trying to understand the missing pieces deeply.

 

As the Labs started to crumble in the late 80s I switched my focus from physics to something more applied - broadband to the home.  The problems were how do you do it and why do you do it.  The later lead to work in digital music and both led me to the notion that I *really* needed to understand social research.  I immersed myself in a human computer interaction department and hopefully helped out a bit with a bit of experimental rigor, very different thinking and a lot of naïve questions that turned out not to be so naïve.  I learned a lot in the process, but the efforts of the group were never coupled to the company at that point.  We did a lot of neat stuff that is finally beginning to be realized now.

 

I still try to search for projects that are looking for a bit of deeper understanding when I consult.  There are a lot of diamonds on the beach these days - as there probably always are.  The approach is rare and I find it odd that I'm sometimes seen as much broader than I see myself.  It is really just a bit of curiosity and the luck of having an amazingly rich chance to work in an environment that makes places like Apple and Pixar look lame when it comes to "multi-disciplinary".  I think there is great value to bits and pieces of the approach as suspect we'll see more of it as the tech world matures and energy becomes a more pressing issue.

 

I don't know what picture the book will paint.  I was witness to an amazing dinosaur and hope some of the better features of the place can be replicated.

 

We had a crisp definition of innovation. The physics people had a crisp definition of data and information.  I find the physics defnition at odds with common usage and I'll post on that in the near future - I've hinted at it before.  Data isn't basic...

 

Om recently commented on creativity talking about John Maeda of RISD.  This caused me to think of some comments from the professor of a graduate physics course I took as an undergrad.  The professor was famous for his creativity having been sprinkled with Swedish holy water.  Somehow he wanted to get over a few points on being creative - he thought you could inspire it.  

 

from my notebook:

 

° be curious about anything and everything. expose yourself to different people and ideas

° don’t be frightened to try the unknown. Many solve puzzles by figuring out what they can do with the puzzle pieces they have. A better approach is to figure out the missing pieces and solve a puzzle you don’t know anything about by learning about them.

° remember it must be play

° the delight is not in finding the answer, but in coming to it yourself

° be totally honest

° deeply know everything about your problem

° real creativity simplifies – aim for simplicity as it is beautiful

° get into something so deeply you forget everything else. you need large pieces of uninterrupted time

 

much more on these later, but back to the old Bell Telephone Laboratories for a bit. When I first started I was delighted to learn that my first director was something of an aurora expert.  He was invovled in the Telstar communications project and was involved in the beginnings of creating the field of what is now called space weather. He would have loved this time lapse of the aurora taken from the ISS a few days ago...

 

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¹ Pixar uses centrally located washrooms and has a design that reminds me of Murray Hill on a much smaller scale.

² IBM, Intel and Microsoft do longer term work in the tech sector. Apple has a ten year horizon for some projects, but anything longer than three years is very rare in industry. One of the longer term interests was video telephony. Here is something on developments in color video telephony .... in 1930.

dealing with incomplete models - understanding nutritional energy balances

What happens when you are trying to modify your behavior with information that comes from measurements that can be difficult that feed into models that are fundamentally inaccurate even though the you may not suspect the models are flawed?  How do you understand this well enough to get a useful signal in a very noisy environment?

 

For many of us the period between Thanksgiving and the New Year involves way too much food. I’m trying to maintain my weight after a serious ten month diet and this means measuring and tracking what I eat as well as my exercise. 

 

It should be simple - after all, energy is always conserved.  Food is just a way to store energy.  If you eat as much as you require to stay alive, your weight should be stable.  Eat a bit less and/or do a bit more physical work and you should lose weight. Take in more than you need and your body tries to hold onto the extra energy by turning it into a energy stored in you - body fat.

 

But to do this simple calculation requires you have to know how much of the energy in food is accessible to your body, how much energy your body uses to run itself and how much energy it takes for you to do any kind of physical work.  All of these are difficult to know to a good degree of precision.  We have published guidelines, but few of us consider the error bars on the underlying measurements and calculations and some of the pieces are still being discovered by basic research.   

 

We tend to assume food nutrition labels are accurate, but it turns out they are based on a technique that is about one hundred years old.  That system, the Atwater System, has known flaws, but nothing has been found to be easy to use and more accurate.

 

Wilber Olin Atwater was a professor at Wesleyan University and a central figure in understanding modern nutrition.  By the mid 1800s people had worked out that proteins, fats and carbohydrates were major components in human nutrition and estimates were made of how much energy was available from each through metabolism.  

 

Atwater spurred the creation of an American nutrition research enterprise - one of the first examples of government funded big science outside of the military - and calculated how much metabolisable energy was available in proteins, fats and carbohydrates accounting for the efficiencies of digestion.  It became possible to measure the chemical energy in food  components and predict how much we could use.  You could simply measure the amount of protein, fat and carbohydrates in a food and determine how much energy the human body would extract.¹

 

The current standard used in the US and many other countries takes into account a few other nutrition sources and food labels are based on the following conversions:

 

	kJ/g	kcal/g
fats	37	9
proteins	17	4
carbohydrates	17	4
fiber	8	2
ethanol (alcohol)	29	7
organic acids	13	3
polyols	10	2.4

 

It turns out this is only a general approximation and to first order you can get away with just looking at the fats, proteins, carbohydrates and alcohol figures if you are creating your own recipes.

 

But your efficiency at absorbing food varies.  New work that looks at how the food was prepared suggests that food that is mechanically made into smaller bits is more efficiency absorbed and food that is cooked is absorbed even more metabolised.²  The largest effect is cooking.  Muscle proteins, sugars in starches and other energy laden molecules are physically opened up allowing digestive enzymes to attack their amino acid chains more effectively.  Food that is cooked gets more of its energy into your system than food that isn’t.  The science is still developing, but some researchers speculate cooked foods provide at least 10% more energy than raw foods and the number may be higher than 25% - I wouldn't be surprised given some of the preliminary results. 

 

The effect of cooking is not accounted for by nutrition labels.  So if you want to lose a bit of weight you might try increasing the raw food component of your diet.

 

The energy balance for your body has four general components: energy intake from eating, energy expended keeping your body running, energy spend doing physical work, and energy spent in thermogenesis (shivering for example).  Physical work comprises about  20% of the average person's energy budget, thermogenesis is usually under 10%.  Most of the energy we use goes into keeping our bodies functioning - our  Basal Metabolic Rate (BMR).³

 

Once you have an idea what your BMR is you can add up all of the physical activity during a day and have a fair idea what your intake should be - assuming you have a good idea of how much energy your body is getting from food.  This gets tough, so most people who worry about this talk in terms of basic activity levels that range from 1.2 for sedentary office workers to around 2.0 for people with physically active lives.⁴

 

My BMR approximation is 1,583 kcal a day by the basic calculation.  Colleen’s is 1,724, but her real figure is higher as she is very athletic.⁵

 

If you exercise regularly you can calculate the energy spent during exercise and add that to your BMR for a rough approximation - a lower limit as you move around doing other things during the day and there is some thermogenesis.  Unfortunately energy spent during exercise is only an approximation as our efficiencies vary person to person for various exercises.  That said you can probably get 80 to 90% accuracy using tools like this one.⁶

 

If you have made it this far the act of journaling your calories and exercise appear to be a futile effort as there is a huge amount of underlying complexity.  But you can get around that.

 

Keep track of your weight too.  If you plot the results you can get an idea of what your measurements for activity and eating mean assuming the types of food you eat and the activities you do don’t vary dramatically.  The numbers may not match what you would measure in a lab, but getting the bottom up numbers to match the top down results is extremely difficult even in that setting.

 

Absolute numbers are very difficult to measure in this case, but it is possible to come by a stable relative measure, and that is all most of us need for this purpose.

 

My goal was to lose about 5 pounds a month while dieting.  Using the rough figure that a pound of fat (what I wanted to lose) is about 3,500 Calories, I aimed at an average daily deficit of about 625 Calories through a combination of exercise and eating less food.  It worked and I was able to maintain a fairly constant rate until near the end when I wanted to gracefully transition to an exercise/eating routine that might be sustainable.⁷

 

Even though we have flawed models for how much energy we absorb from our food and how efficient our bodies are, the models are sufficient - with a bit of analysis - to effectively use as a tool for losing and maintaing weight.  It is easy to imagine local refinements - I’ve created a tool that helped me understand my own information flow and ultimately how that translates into weight - and it is likely that activity monitors like accelerometers can help, but in the end simple willpower rules.  I suspect many monitoring and computational aids will ultimately fail unless they can impact our basic urges.  To control something you need to combine motivation, the ability to make a change and some triggering event.  I’ve worked that out for myself.  Building a general tool seems difficult.

 

Perhaps what we really need to do is find the levels of eating and activity that evolution assumes.  Up until the Industrial Age people appear to have been self regulating in weight.  Now foods tend to be more plentiful, have greater energy densities and perhaps are even more palatable.  At the same time many of us are less active.  The balance is thrown and many of us gain weight easily.  Finding the right balance is tricky as evolution did not design us for a long and healthy life - basically we get to the point where we have been able to reproduce and then things begin to fall apart.  So the full nutrition offered by earlier diets may be very suspect even if the energy balance is good.  There is probably quite a bit to learn here.  Some of us (not me) are fortunate enough to have bodies that are great at self regulation.  Exactly how that happens is a very interesting question.

 

_________________

 

So now we shift gears and present a few deadly recipes:-)

 

No one seems to be complaining about the recipes and three people have asked for more, so here are two rich desserts - a banana cream pie and a lemon tart.  Both use the same shortbread crust.    

 

I think of baking and cooking as two very different arts and suspect few really outstanding cooks are also outstanding bakers.  Cooking demands knowing the state of the food and how flavors link up - there is a lot of improvisation that occurs as you cook so measurements are just a guide.  Baking, at least for me, demands careful measurements for ingredients and cooking, so I use weights rather than volumes.  I have a great $25 scale that measures accurately to the gram and recommend something like this to anyone who bakes.  I’ll leave the conversions to you if you bake using volumes.  

 

Both of these are very easy, delicious and something you should only eat sparingly.  They were part of Sukie’s birthday present a few days ago.

 

The shortbread pastry crust is really simple and no rolling is required.  Just put a few ingredients into a food processor, pulse a few times, and press into a tart pan.  I do recommend very fresh ingredients for baking.  Sugar or flour that has been opened and sitting around for a month or so pick up a funny taste.

 

Shortbread Pastry Crust

 

130 grams all purpose flour

35 grams powdered sugar

 a pinch of fine sea salt (too small for my scale - I’m guessing about 1/8tsp).  Note that iodized salt picks up a strange flavor when baking, so I use a fine grain un-iodized sea salt

 1 stick of cold unsalted butter - about 115 grams

 

 procedure

 

° heat oven to 425°F with the rack in a center position

° butter or lightly spray with a nonstick neutral vegetable oil cooking spray an 8” tart pan with a removable bottom. 9” would probably work too.

° cut the butter into chunks and put all of the ingredients in a food processor 

° pulse the food processor until the pastry starts to form into pea sized clumps - about 30 seconds for me.  don’t let it grow into larger pieces if you can.

° press the dough into the pan and pat as evenly as you can

° pierce the bottom of the crust with a fork to prevent it from puffing up too much during baking.

° Cover the pastry with plastic wrap and put it in the freezer for 15 minutes - this is a really neat trick that prevents the crust from shrinking when it bakes.

° Bake until the crust is golden brown - about 15 minutes for me.  Cool on a wire rack.  You can cover the crust and store it for a day in the refrigerator f you want. 

 

Lemon Tart

3 large eggs at room temperature

150 grams granulated white sugar

80 grams fresh lemon juice (about 3 lemons)

a half stick of butter - about 56 grams - at room temperature - cut into chunks

4 grams of lemon zest (be careful to only get the yellow part!)  I prefer a microplane for doing this

shortbread pastry

30 grams finely chopped almonds

blueberries and maple syrup - thawed frozen blueberries are fine

 

procedure

° In a double boiler over simmering water whisk the eggs, sugar and lemon juice together

° Cook, whisking or stirring with a spatula, constantly until the mixture becomes pale and thick - about 160°F.  This takes about 10 minutes

° Remove from the heat and strain to remove lumps.  

° Whisk the butter into the mixture until melted and add the lemon zest.

° Cover with a plastic sheet pressed to the surface of the lemon curd to prevent a skin from forming and let it cool to room temperature before filling the crust.

° Assemble covering the inside of the crust with finely chopped almond bits and then pour in the lemon curd.  Even out with the back of a spoon or a pastry knife.

° Separate the pie from the pan - just carefully push from the bottom

° Add maple syrup to the blueberries and spoon on to individual pies of the pie when you serve.  Sweeten as much or as little as you like.  

 

 

Banana Creme Pie

 

300 grams whole milk

half a  vanilla bean (you could use a good vanilla extract - maybe about a half tablespoon)

 3 large egg yolks at room temperature

 50 grams granulated white sugar

 20 grams all purpose flour

 20 grams corn starch

 3 large ripe bananas

 40 grams shredded coconut

 whipped cream (recipe at the bottom)

 

procedure

 

° Score the vanilla bean and add to milk in a saucepan and start heating at a medium heat

 ° While this is cooking mix the sugar and egg yolks together. then sift the cornstarch and flour into the egg/sugar mixture to make a thick paste.  Don’t let this sit around as it gets very lumpy if you do.  

 °Stir the warming milk.  Take it off the heat when it begins to foam and remove the vanilla bean.  Slowly add the hot milk to the paste whisking constantly.  

 ° Scrape out the seeds from the bean and add to the mixture.  If you use vanilla extract instead, now is the time to add it.

 °Pour the mixture back into the saucepan and heat over medium heat until it begins to boil and thicken.  

 ° Pour the mixture into a clean bowl and press plastic wrap to the top surface to prevent a skin from forming.  Let it cool to room temperature.

 ° Slice the bananas and fold two in with the cooked mixture along with the shredded coconut.  Pour into the pasty.

 ° Top with whipped cream and carefully release the pie from the pan side ring

 

 

Whipped Cream

 

120 grams heavy cream chilled

 15 grams powdered sugar

 1/2 tsp almond extract

 

procedure

 

° Chill a mixing bowl and beater from an electric mixer in the freezer for about 5 minutes.  You can also get good results with a whisk and copper mixing bowl, but that takes some elbow grease.

 ° Pour the cream, sugar and almond extract into the bowl and beat until peaks form.  

 

 

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¹ Atwater showed about 4 nutritional Calories (kcal) were available from carbohydrates, 4 from proteins and 9 from fat. 

² There has been a lot of speculation here, but now serious science is being done that supports the notion that cooking makes more energy available.  A paper by Rachel Carmody and Richard Wrangham in the Journal of Human Evolution is a good example.  Another study found that cooking gelatinizes starch meaning amylopectin and amylose are released and exposed to enzymes making more energy available.  Cooked starches have more available Calories than those that are raw.

 People have known for a long time that people who eat mostly raw food tend to be very thin compared with the general population, but serious studies on those populations are recent and the results spurred a deeper look into the more general question of food processing and available energy.  Women on a purely raw food diet regularly lack the energy to have a functioning menstrual cycle even though they are eating what should be a high quality diet.  The available Calories just aren’t there - we have based our food recommendations on cooked food and our bodies seem to have a body regulation mechanism that is based on cooked food - this may even be a short term evolutionary response, but that is currently speculation waiting on the verdict of science.

³ BMR is difficult to measure directly as it requires the measurement be made while the person is at rest for a long period.  A more common technique is to measure a person’s resting metabolic rate (RMR).  They turn out to be closely related and similar under most conditions.

A frequently used approximation is from Mifflin et. al. (1990):

BMR = 10*weight + 6.25*height -5*age +s  

where weight is in kilograms, height is in centimeters, age is in years and s is +5 for males and -161 for females.  

If you know your lean body mass in kilograms the Katch-McArdle approximation is probably more accurate.

BMR= 370 + (21.6 * lean body mass)

BMR in both of these approximations is in kcal (nutritional Calories)

⁴ One approximation is the Harris Benedict formula:  

sedentary office workers use BMR *1.2 Calories

light exercise 1-3 days a week use BMR * 1.375 Calories

moderate exercise 3-5 days a week use BMR * 1.55 Calories

hard exercise 6-7 days a week use BMR * 1.725 Calories

very hard physical labor use BMR * 2.0 Calories

This is very approximate.  Athletes in training can use incredible amounts.  Colleen was in the 5,000 to 6,000 Calorie a day range when training - easily blowing through the approximation for very hard physical labor.

⁵ Normally men have higher BMRs than women even when they are the same height and weight. Men, on average, tend to have a higher percentage of lean muscle.  Colleen is a bit heavier than me and, at 200 cm, quite a bit taller. She is also younger - all of this is enough to give her a higher BMR.  Since she is thin and athletic you really need to use a different approximation as her body fat is low at around 10%.  The Katch-McArdle formula gives a better BMR estimate of 1,925 kcal

Some unit notes:  Energy is just energy.  kilocalories (kcal) are the same as nutritional calories (Calories).  Converting 1,925 Calories to watt-hours we see Colleen’s BMR is about 2,239 watt-hours a day.  You can divide this by time to get her average power expenditure from BMR -- a bit over 93 watts.

In an inactive office worker mode she would need about 1.2 * BMR or 2,310 Calories a day - a figure that would cause a smaller person, even someone who is fairly active, to gain weight.  Of course a very heavy person would have a very high BMR and their weight loss in pounds per month can be very high.

⁶ Note that this is energy used above and beyond your BMR.  Often people assume the exercise figures are a person's total requirements during the exercise period.

⁷ I strongly recommend a good piece of software for logging exercise and meals.

Now I can deduce my daily requirements to be about 2,190 Calories per day.  This is consistent with my calculated BMR times a factor of about 1.4 for my normal daily activity.  It sort of makes sense.