omenti

tree power!

The local cherry trees are currently covered with pink and white popcorn.  Nature is beginning to unfurl her solar collectors .  I found myself wondering how many watts of power an average oak around here produces.  A detailed calculation would be very difficult, but fortunately a reasonable approximation is easy - a good example of play to create an estimate of something rather involved

 

To get the average you need the average amount solar power that falls where you live.  You can start with the number for the Earth in  orbit, correct for the elliptical orbit, take into account the geometry of the Earth, the fact it spins on its axis, then correct for the seasons and the weather ... ugh ..  or you can look up the number that was obtained experimentally close to where you live.  Now approximate an average tree and calculate the amount of energy that falls on the tree during the time when it is in leaf.  Now consider what is meant by power produced.  Some of it goes into keeping the tree alive, but a reasonable definition might be the energy in the biomass it produces from photosynthesis.  That's about all you need.  The details of the quick mental calculation are in the footnote, but the bottom line is a fifty foot oak averages about 80 watts - a tenth of a horsepower - during the full leaf season in New Jersey.¹  This is the average through day and night, but during the day in bright direct sunlight the tree is probably up around 200 watts.  This is an unexpected coincidence with the power requirement of a human- someone who eats 2,000 calories of food a day averages about 100 watts of input power from the food.

 

The low efficiency of the tree's photosynthesis is impressive - 0.5% in this case.  It turns out deciduous trees average 0.2 to 0.5% efficiency, so the approximation isn't terribly wrong as back of the envelopes go

 

Photosynthesis keeps life running on Earth.  Plants convert carbon dioxide, water and energy from sunlight into a sugar and oxygen.  Everything you eat ultimately came from the process.  It isn't terribly efficient - some crops manage to top one percent efficiency, but not by much. By contrast photovoltaic cells with 20 percent efficiencies are common.  Theoretical efficiencies for photosynthesis are higher - something like seven percent, but Nature didn't find a need to work out how to get there.  

 

It wouldn't make much sense for animals or people to be able to do photosynthesis.  We may be able to receive a half square meter of sunlight under ideal conditions if we ran around in warm sunny climates wearing little or nothing. If we sat outside all day that might bring in a half watt or so.  About what your smartphone uses and forty times less than your brain needs.  We need plant life -  a lot of it.

 

This sort of number might seem frivolous, but you can set food, or any other plant product, limits by working with a related number - how much biomass of a crop can be produced per hectare.  Back of the envelopes tell us that some activities like eating meat at American levels don't scale to the world's population - there simply isn't enough available land area to raise the required crops.   This is a big problem as societies gain wealth and begin to eat more meat as making meat is very inefficient often requiring at least ten kilograms of vegetation per kilogram of animal produced. 

 

Thinking in terms of power per unit area is a very useful approach for thinking about diffuse energy.  You can easily set limits to how much of certain types of energy can be produced in an area.  Conversely you can consider how much power a society consumes per unit area to see if a county can be self sufficient with a mix of alternate energy types.  These are great tools for dealing with claims that seem a bit suspect and by setting conservative limits even crude back of the envelope calculations can be compelling.  This is also a good approach for estimating how many years of vegetation are required to produce a year's worth of fossil fuel consumption - another very difficult problem where the trick is to set limits.

 

But back to the trees.  Oxygen, the 'waste' product of photosynthesis, is sort of useful to us.  How many trees are needed to support you?  There are a number of ways to come up with a number.  Another back of the envelope suggests about eight fifty foot oaks in New Jersey would keep me breathing.  I'll stay away from boring you, but the next time you take a walk in a park or forest remember to thank the trees - our partners in life.

 

___________

¹ Here's the mental calculation I did - partly to show the approximations you can make when you know you're just looking for a ballpark number.  If you play with numbers these things long enough you remember numbers and conversion constants.

° the average solar energy per day for this part of the country for April through September is about 4 kWh/m² per day and trees are in leaf about 220 days a year.  

° an average mature oak is about 50 feet tall.  I approximate the leaf area by a disk with a radius of 6 meters or an area of about 100 m²

this → 88,000 kWh for the oak per leaf season

° a 50 foot oak has a dry mass of about a ton - I'll call it a metric tonne.  It produces about 100 kg of new dry wood a year

° dry wood has an energy content of about 16 MJ/kg or about 4.4 kWh/kg

this → 440 kWh of energy from the dry wood and an efficiency of 440/88,000 or 0.5%

440 kWh/leaf season → 440kWh/(220 d * 24h/d) or a bit over 80 watts average

 

 

egg illusions

Even though I'm not very good at it I find art a very important part of the playful part of math and science.  I've bemoaned the narrow-minded focus on STEM in schools enough, so here's a delightful example.

 

Before film it was discovered we have a persistence of vision - the mind stitches together smooth motion by combing something like 25 still images per second.¹  In the early 1800s the zoetrope was invented.  A drum with image frames painted on the inside would be spun.  It had a series of slits around the periphery that you would look through to watch the short animation.  These became toys of the Victorian era leading to more sophisticated design.  

 

Stitching moving still frames into an illusion of motion led to something of the inverse.   A blurry vibrating guitar string viewed using a bright light that flashes with a regular frequency appears to stop.  The stroboscope has a wide range of application - you've probably used one in a high school science class and electronic versions that only display the repeating parts of a signal are fundamental to electrical engineering.

 

You can write on the surface of a spinning object and by picking the right frequency of a flashing strobe light motion will appear.  Now what if you could do this on a complex surface?

 

The EggBot is a delightful little piece of tech.  A computer controlled printer that draws on spherical and roughly spherical shapes. Balls and, well, even eggs.  Jiri Zemanek at the Czech Technical University in Prague generates interesting patterns in Matlab which was used to drive his Eggbot.  Then he spins the eggs and adjusts the frequency of a strobe light.  Art, math, science and engineering and a bit of time for your imagination to take flight.

 

__________

¹ At least most of us think persistence of vision is what allows us to view motion in film.  It turns out to be more complicated and a combination of persistence of vision and the phi phenomenon.  Persistence of vision is why you don't see the black spaces that come before each frame in a film.  The phi phenomenon is the apparent motion of a sequence of still images.  

 

raising sigma

For the past three months there has been real excitement in the physics community.  Oh the direct detection of gravity waves was a huge, but it was sort of expected.  Gravitational radiation have been seen indirectly for some time and upgrades to the LIGO detector was going to be sensitive enough that detection was likely if Einstein was to be believed.  A great discovery and probably a Nobel Prize, but more importantly a new branch of astrophysics and cosmology has been opened - we have an entirely new kind of telescope.  Wonderful, but the real excitement has been a bump in the diphoton spectrum recorded at Atlas and CMS at CERN at 750 GeV.  In December it was 2.6 sigma at Atlas and now is around 3.6 at both detectors.  Gibberish and blather for most, but for a few others an electric excitement linked to passion.  

 

So why mention this...?

 

Our economy increasingly depends on information.  Information, at least contextually meaningful information, has become a commodity.  Recently Charlie pointed out that some disciplines that should value carefully vetted information don't.  His comment and the current excitement in physics suggested an opportunity to talk about tempering excitement with being careful while engaging in some incredible play.  I'll jump into a bit of the sausage making in physics, but will try and stay away from the technical bits.  First some motivation.  

 

In the mid 70s it became clear a theoretical model called the Standard Model explained a good deal of fundamental physics.  It nicely unified the strong, weak and electromagnetic forces - only gravity was left out.  It made a number of predictions including the Higgs field which partly explains how mass comes about.  But although it has been enormously successful it has some serious issues.  For example it doesn't shed any light on why gravity is so weak - why is it 100,000,000,000,000,000,000,000,000,000,000 times weaker than the weak force?  This turns out to be part of the hierarchy problem - the electron is about 200 times lighter than the muon and 3,500 times lighter than the tau.  Likewise for the quarks: the top quark is 75,000 times heavier than the up quark. Nature's lego set has blocks that vary widely in size.  The hint is some other undiscovered particles lurk.  If something called spontaneously broken supersymmetry exists, I'll stay away from talking about that for now, many of the pieces fall into place.

 

A hunt for supersymmetric particles has been underway for a few decades.  One of the reasons for building the Large Hadron Collider and its detectors was to find and learn about the Higgs field, but searching for supersymmetry as well as entirely new physics is at least as important. To date supersymmetry hasn't panned out.  There are physicists who have spent a few decades focusing on this in theory and experiment, but hard work and wishing doesn't impress Nature.  The great thing about science is ultimately Nature is the only standard.  It isn't quite time to call it quits on supersymmetry, but it has been rather quiet.

 

So a few months ago word leaked out of a small bump - a resonance indicating a particle might existing with a mass of about 750 billion electron volts - about five times as massive as the Higgs boson and about 800 times greater than that of the everyday proton.  The evidence wasn't great - 2.6 sigma at one of the detectors, but it was seen in both detectors at the same mass.  

 

In particle physics the standard for claiming a new particle exists is five standard deviations - five sigma.  Many two and three sigma bumps have faded upon closer inspection.  The game is to have enough collisions to get good statistics and understand the signal at a very deep level.  The fact that this isn't a discovery yet doesn't mean it isn't exciting.  Experimentalists will look more carefully when the collider is running again and in the meantime everyone is looking for flaws in what they've done so far.  Unlike some fields you can have considerable stature showing a claimed result is false . This is exactly what happened with the primordial gravity waves that were announced by the  BICEP2 collaboration two years ago.  This electrified the physics world as it was such a beautiful story - the problem was they didn't understand the signal's noise background deeply enough so they had to retract.

 

People are past the wtf stage.  Now experimentalists are trying to understand the background (these signals are embedded in piles of noise that necessitate the use of multiple filters - you need to make sure you aren't fooling yourself) and preparing for future runs the theorists are engaged in serious play seeing if there are theoretical frameworks that can explain the signal reported to date and perhaps make a prediction or two - experimentally testable hypotheses.  Today I looked at the arXiv - over 300 papers trying to explain what is going on.   Many theory papers are somewhat polished versions of the neat idea that you can't dismiss after a few weeks of work.  Papers at this level a kind of communal work in progress.  Sometimes the preprints have a feel of the weekly colloquium.

 

Particle physics has an open atmosphere where people communicated by preprint.  When I was a grad student in the late 70s the practice was at the point where fax machines were working around the clock and the main reason for looking at final journals was for references in your papers.  This openness lead to the need for doing something on the Internet and Tim Breners -Lee's project led to something rather useful called the web.¹  

 

Back to this statistical significance thing... what is five sigma?

 

Five sigma corresponds to a probability or p-value of 3 x 10^-7 or 1 in 3.5 million.  Now for a few important comments. This is not the only standard for discovery! It happens to be one that is important, but you'd be deluding yourself if you only relied on it.  Also it doesn't mean the Higgs boson does or doesn't exist.  It would be sweet if you could talk about probabilities that something existed, but there is a tricky 'if' in the real thing.  It is the probability that if the particle does not exist, the data taken at the Large Hadron Collider, would be at least as extreme as what they observed.

 

A researcher will  use p-values to test the likelihood of hypotheses. In an experiment comparing some phenomenon A to phenomenon B, researchers construct two hypotheses: that A and B are not correlated - the null hypothesis, and that A and B are correlated- the research hypothesis.  Now she assumes the null hypothesis (it's the most conservative supposition, intellectually) and calculates the probability of obtaining data at least as extreme as what is experimentally observed, given that there is no relationship between A and B. This gives the p-value, can be based on any of several different statistical tests.

A low p-value is low means there there is only a small chance (p=0.01 is one percent) that the data would have been observed by chance without the correlation. Different fields of science have established gold standards.  Some of medical and social science use p = 0.05.² 

 

Sigma is just a standard deviation - just a measure of the how wide a distribution of data points is about a mean.  It takes a very specific meaning for a normal (gaussian) distribution - its usual context.  A large sigma means the data are spread out - a wide curve rather than a spike.  You can use this to measure how much of of the data is within a certain range.  Again for a normal distribution about 68% of data points lie within one sigma, 95% within two sigma and so on.  If something is five sigma out it means it is to the left or right of most of the curve fewer than one in a million.  The numbers quoted in particle physics imply it is all on one side of the curve, which is where the 1 in 3.5 million comes from.  Pretty rare.³   The initial diphoton excess signal sigma that got people's attention was 2.6 corresponding to a probability of 4.7 x 10^-3 or about 1 in 215.  A sigma of 3.6 yields 1.6 x 10^-4 or one in about 6,300.  Not good enough, but part of the added information is that the signal was seen at both detectors at the same energy - another bit of probability to play with.

 

This process of finding the sigma of a signal isn't direct or easy.  There are tens of thousands of data channels and filters making their own contribution.  Each of these needs to be understood (that means almost constant verification and calibration) and has its own contribution.  All of this goes into a big number grinder where everyone who touches a component has his or her fingerprints on the final result.  People err on the side of being conservative.

 

OK - that's one very cautious and conservative community when it comes to understanding information.  What about the rest of us?    How well do you understand the filters on social media?  How about the regular news?  How about information that is mission critical to business decisions you make?  Who has their fingers on the information as it is processed and exactly what is happening to it?  How do you verify it?  Do you verify it?  How deep is your trust?   Some of these are qualitative others are quantitative and some are in between...  

 

I've been asked to look at a fair amount of data visualization and processing over the years.  Some of it is great, but much of it - including that from many data scientists - is very low quality.  Sadly it makes up for it in the minds of many for being pretty and for certifying a required result...  If information is a commodity what can be done about counterfeit coin?

 

__________

¹ The spinoff from the pursuit of physics has been remarkable.  Most of medical instrumentation had its beginnings in physics.  The fact you have people trying to measure at a level where they have to invent apparatus is a great way to discover and invent new technologies.  Even dealing with massive amounts of information has made fundamental contributions to computer science and statistics.

² This weak (by the standards of experimental 'hard' sciences) plus a reliance on p-values alone are artifacts of poor repeatability - a serious problem in medical and social science to the point where it can be debated if they are really science. I have quite a bit to say on that, but not now.  Some of medical science is based on single studies, often with drug company funding, that are about as good as flipping a coin.  I use a commonly prescribed drug based on this level of confidence.

³ A friend is very tall - her height is about five sigma out from the mean for women's height.

__________

Recipe Corner

 

There are several approaches to Phat Phrik Khing...  As a vegetarian I've made my own curry paste as most varieties have shrimp paste or fish sauce.  Thai Kitchen has a vegan red curry paste that is widely distributed (supermarkets and Amazon) and it is an ok base for throwing something together quickly.  You can also make your own sauce with a visit to an Southeast Asian market for galangal and makrut lime leaves (also online).  If you make your own the difference in flavor between using a mortar and pestle and a food processor is huge, so do it by hand.  If you can find fresh tofu, many Asian markets offer it, go for it as it is vastly superior to the stuff you find in supermarkets. The rough guide has a homemade sauce, but you can substitute a store bought and, of course, you can substitute meat for the tofu is you like.  You can use vegetable or coconut oil.   (the base recipe was copied from an article while waiting in a dental office a decade ago)

 

Phat Phrik Khing  

 

Ingredients

 

° 6 dried guajillo, California, or pasilla chilies, stemmed and seeded 

° 6 medium garlic cloves, roughly chopped

° 2 medium shallots, peeled and roughly chopped

° a few red Thai bird chilies, roughly chopped - I like a mild heat so 2 or 3 for me.  If you are into heat use more!

° 1 large bunch cilantro stems, roughly chopped

° 3 makrut (kaffir) lime leaves fresh or dried, discard the hard central stem, leaves roughly chopped

° 1 stalk fresh lemongrass, bottom 4 to 5 inches only, discard the tough outer leaves and slice the core thinly 

° 1 inchish knob galangal, peeled 

° 1/2 teaspoon freshly ground  pepper

° Kosher salt

° 3 tablespoons vegetable oil or coconut oil. 

° 1 340g (12 ounce) block of firm tofu, cut to one by one by half inch, press firmly between paper towels to dry 

° 1 pound  green beans, trimmed and cut into one and a half inch lengths

° 1 tablespoon sugar

° 1 tablespoon  soy sauce

°  Your favorite teamed rice for serving

 

 

Technique

 

(homemade sauce)

° Place chilies in bowl and cover with boiling water. Cover the bowl and set aside for 10 minutes.

° Put the garlic, shallots, chilies, cilantro, lime leaves, lemongrass, galangal, ground pepper, and about a tablespoon of salt in a mortar and pestle and pound away 'till you get a rough paste. Drain chilies, add to mortar, and continue pounding until well distributed - it doesn't need to be super smooth. 

(commercial sauce)

° use enough red chili paste - about 8 to 12 ounces depending on your taste and the tofu and beans you have

____

 

° Heat a tablespoon of  oil in a wok over medium-high heat until shimmering. Add tofu, spread into a single layer, and cook, occasionally shaking pan gently, until crisp on one side, (3 or 4 minutes).

° Flip tofu and continue cooking until second side is crisp. Transfer to a bowl and set aside.

° Add a tablespoon of oil to the wok and crank heat to high. When oil is not - close to smoking - add beans and cook, stirring and tossing occasionally, until blistered and tender, (2 to 4 minutes depending on how hot the oil is and how brave/crazy you are). Transfer to bowl with tofu.

° Add the remaining tablespoon of oil to your wok and return to high heat. When it is hot add the curry paste all and cook constantly stirring, until sizzling, (about 1 minute). Return tofu and beans to pan, along with sugar and soy sauce. Stir and toss to combine and coat tofu and beans in curry paste. Season to taste.

° Serve immediately with steamed rice.

 

which high fiber diet makes sense?

A few weeks ago Google Fiber announced they had a partnership with  Huntsville, Alabama.  These announcements were once exciting, but over time shifted to mildly interesting and then to - well - just ho hum.  Google's motives appear to have shifted over the years and there is this nagging issue of an access provider also being a major service provider.  So I didn't pay attention to the press release until a few days later when Susan Crawford posted.

 

You Didn't Notice It, But Google Fiber Just Began the Golden Age of High Speed Internet Access

 

In technology as with politics there are any number of pieces over the top with excitement about possibilities.  Most of them never amount to much, but you pay attention when a friend who usually isn't taken with hyperbole gets excited.   I read her piece and then thought a bit.

 

Huntsville owns their own fiber.  Initially installed for remote metering and other infrastructurish projects, it has a lot of capacity - after all, most of the cost of fiber is digging trenches - the fiber itself is so cheap the difference between one and forty-eight strand fiber is almost nothing.  It is common for cities to own their roads, water and sewer and sometimes electricity and natural gas lines - after all - this is just common infrastructure that everyone uses. 

 

Given Internet penetration rates you can make the argument that municipal fiber makes sense, but municipal ownership and the ability to offer an Internet connection is comparatively rare.  In addition to a pile of new debt it takes a fair amount of technical and business expertise to build and run a service.  Making matters worse the connection incumbents - telcos and cables - have powerful lobbies at the state level and have been erecting high barriers.  

 

Susan is excited that Huntsville deal is not exclusive to Google.  They are offering access to their dark fiber. Google, and anyone else with the wherewithal, can come in and light up strands and offer connections to homes and businesses.  Neat - it sort of sounds like the fantastic Stokab municipal fiber project that has been in operation for nearly two decades in Stockholm.  Multiple access providers can offer access to anyone and competition has driven down the price of very high speed symmetrical connections   to the point where most of us can only be envious.  As successful as Stokab is there have been few imitators ..  det är de små, små detaljerna som gör det.¹   

 

I went over to the Community Broadband Networks site - a group representing and connecting those who have been taking on the incumbents to provide access.  They had just posted a podcast interview with some of the Huntsville principals and I hadn't done my exercises ..  a good excuse to listen rather than search and read.  

 

It turns out the system is PONS - a passive optical network.  Cheap, but inflexible.  There will be thousands of splitter boxes spread throughout the town with each serving four to eight residences.  The access provider would sign people up and 'own' whatever customers they could attract.  They would run a connection from the splitter closest to the customer to the customer owning the last several hundred feet - the connection from the PONS fiber to the customer. It was mentioned that Huntsville would offer a volume discount.  This would favor large providers.  The situation is likely to favor a major provider and perhaps another smaller player.  We're left with what we've had - an oligopoly.  

 

Google might take a different tack.  Rather than dig a trench and run a fiber from the splitter to the customer, Google might go wireless.  They've been playing with short and medium range wireless for several years and have been lobbying the FCC for some interesting frequency bands.²  With volume pricing and the hurdle of the cost differential between Google's wireless and a trench, it may be that oligopoly becomes an effective monopoly. 

 

This may well be cherry picking for Google Fiber.  It isn't as if they haven't been doing that to date.  It could even be a big thing if a lot of cities owned their own fiber infrastructure.  But there aren't many places this can be done.  Some of the cities that have done it, Charleston (which still is fending off attacks from telcos and cables) and  Baton Rouge have taken more sophisticated approaches.  Ting is doing a fiber deal with Westminster, MD that looks better than Huntsville/Google.   There are dozens of very small and rural municipalities and even buildings in cities that are rolling their own using a variety of models.  The point is there isn't any one size fits all and there is still enormous legal harassment from the incumbents.  So don't expect much change soon.  But for the longer term...

 

In the longer term there will probably be change.  Verizon pulled through the halt switch on new cable deployment.  I live in town that happens to host Verizon's headquarters and face a monopoly - Cablevision is the only access provider in my part of town.  The DOCIS cable standard is a hack.  The download peak speeds have improved dramatically, but upload speeds are terrible and it is likely not to improve much - not to mention the cable companies are facing cord cutting and have been playing around with data caps. To say they are pissing off their customers is understatement and dramatic change will take place over the next few years.³   A few locations will have their own fiber and will have multiple options as to how they light and distribute it.  Wireless is improving dramatically.  It seems reasonable that a city might have hundreds or even thousands of configurable wireless stations getting backhaul service from close enough fiber.  And very dramatic things can be done with software defined radio.  

 

In the long run the losers may well be the cables and telcos... and that includes conventional wireless providers.  In the long run it is likely an air war.  Hopefully the FCC and FTC will side with consumers and technology.

  

__________
¹ The devil is in the details.  - a tip of the hat to Anders

² My favorite is one dedicated to short range Naval operations. While heavily used in places like San Diego, Norfolk and Seattle, it isn't exactly busy in Kansas.

³ We're on the left side of the adoption S curve for cable cutting.  At some point the slope increases dramatically and the cables and their dance partners are in serious trouble.  For the time being they note defections are small, but people under 30 are not signing up for service.  They also claim that some programming - notably local and sports - will keep a large majority with them.  But when cord cutting gets in the 10 to 15 percent range with a steeply rising slope, sports and local providers will have no choice than to offer Internet accessible services.  

At some point people notice that telephony and television is just better over the Internet.  Lobbyists will get rich, but in the end the incumbents lose unless they figure out attractive Internet offerings.

__________

Recipe Corner

 

I love roasting vegetables, but when new Spring produce turns up I tend to braise to highlight their delicate flavors.  It is also great in the late Summer when the produce floodgates open wide.  Olive oil braising gives terrific flavor .. you don't need a fine finishing oil, but use a real olive oil rather than a cheap blend.  Trader Joe's Extra Virgin California Estate is about a fifth the price of a good finishing oil and is great for a dish like this.  I can't say the same of some of the other TJ's oils.  The recipe is a modification of a standard oil braising technique and is just a guide, so read it, put it away and use what you have!

 

 

Vegetables Braised in Oil

 

Ingredients

 

° 1/2 cup olive oil

° a lemon, cut into thin wedges 

°  some sun dried tomatoes, cut into strips (about a third of a cup for me)

° 3 cloves garlic

° pinch red chili flakes

° sprig of rosemary

° salt & pepper

° 1 pound baby red potatoes halved 

° 3 shallots, quartered

° 3 or 4 baby carrots cut into medium sized sticks

° 1 asparagus bunch , trimmed

 

 

Technique

 

° Heat olive oil on medium high

° add about a quarter of the lemon wedges and bring them to a light brown

° add the sun dried tomatoes, garlic cloves, red pepper flakes and rosemary, and stir for just a minute

° cut the heat to medium low and add the new potatoes, shallots, and some salt and pepper. Stir to coat with the oil and cook for about 20 minutes.

° now add the carrots, stir to coat, and cook covered for another 20 minutes. Check to see that veggies are fork-tender but not falling apart. Add asparagus, again stir gently to coat, and cook covered until asparagus is just done (about 8 minutes for me)

° Remove from heat and serve with lemon wedges and perhaps a bit of parsley or basil 

This is really good with a crusty bread!

 

 

optics on the cheap

Judging a regional science fair year ago I noticed two types of kids.  Most were on a pre-professional/get into a good college track.  Many were interning in real labs.  Great experience, but very few had any depth.  Then there were  the kids who were working on projects of their own.  This was a regional science fair and most of the low quality entrants had been weeded out.   Some of these homebrew types reminded me of C.L. Strong's Amateur Scientist Scientific American column that ran during the 50s and 60s. These were seriously motivated kids. 

 

The project that grabbed my attention was more technology and experimental apparatus than science experiment.  Somehow his assigned mentor signed him off as 'safe'.  I was charged with the final safety inspections the first morning of the fair.   His homemade electron microscope had severely dangerous wiring - it would be fairly easy to kill yourself.  I asked him how he would bring it to ground and watched him demonstrate placing a large screwdriver blade across two exposed contacts less than an inch apart.  yikes!  But at the same time it was beautiful.  He had solved a number of engineering and design challenges - the vacuum system was clever and showed a good practical working knowledge.  Except for the high voltage electronics I would have been impressed had he been a grad student.

 

During my ten years of judging I only had to disqualify two out of perhaps five or six hundred projects.   But he was displaying passion and something had to be done.  I brought over two judges from Bell Labs and got him to power it up (under supervision!) for a demo.  The damn thing worked and produced beautiful images.  The next week the 11^th grader was contacted by professors at MIT, CMU and Berkeley with offers to come and visit.  He accepted an offer to MIT during his visit there and was spared the hassle of applying.  Later I learned  he went on from there and is now a researcher building atomic fountain clocks at NIST. His is an extreme example, but you have to love people who are visited with the motivation to build rather than buy.  

 

A reader wanted a digital microscope recommendation for his 11 year old daughter.  I love the idea of kids and microscopes.  Playing in and with Nature is great.  Play where you remove some of the constraints our senses impose makes for an even richer experience.  While there are many cheap digital microscopes on the market, I'd recommend something that attaches to a smartphone as you can take and analyze photos using what is an excellent camera with part of a good optical train.  There are a few you can buy, but why not start by making your own?

 

  I'm answering in the form of a post as it might be interesting to others who know kids or may happen to be one.  It is possible to use a simple lens and project onto a smartphone lens.  All you need to do is figure out some way to hold it and the sample at the right distances.  You could do this with an ice lens, but that is better left to starting fires.  Glass beads work -  a few years ago I built one for an iPhone that produced remarkably clear images - I had to go through a half dozen glass beads to find a good one, but still...  It wasn't very user friendly, but that may be inspiration for making one that is.

 

Here's a very simple 'scope making use of the lens in a laser pointer - you have to love the lens holder.

 

and a 3d printed glass bead holder/smartphone adapter from Pacific Northwest National Laboratory - the file is free.  You can print it at your school, some public libraries or just send the file to a printing company - I can't say I'd recommend buying your own printer at this point unless you are seriously into design and prototyping.

 Once they've learned about microscopy perhaps they'll get excited...  at that point perhaps something more robust with better optics makes sense.  I've borrowed a Bodelin adapter that was great for walking into the woods to see Nature at a different scale.  Then again perhaps she could design her own..

 

_________

Recipe Corner

 

a few weeks ago Gregg V asked for my chili recipe.  For what its worth this one isn't bad and, like many chili recipes, is very tolerant to variation..

rather than type it in, I'll add what I sent to Gregg:

 

Here’s the base recipe I use for the chili … someone sent it to me years ago and I only follow it roughly. In the Winter sticking to canned veggies usually wins .. particularly for tomatoes. I also used canned beans for this as it is thrown together on snowy days.. all cans are the 12-15 oz size here. On beans just throw in whatever you want. I usually go mostly black and pinto, but pick one, all or off the list… On the peppers usually do two red and one green,, the author was going for color. It is way better if you stew plum tomatoes down into a sauce unless you have a great store bought sauce - I haven’t found a good plain one, but in a pinch its ok. The masa/cornmeal addition is the trick. I also usually go for 2 c of broth and 1 of beer (Sukie has the rest:-) Of course the chili powder section is where you may want to go wilder, but this is a good basic filling chili

• 2 Tablespoons Olive Oil
• 4 cloves Garlic, Minced
• 1 whole Large Onion, Diced
• 1 whole Red Bell Pepper diced
• 1 whole Yellow Bell Pepper diced
• 1 whole Green Bell Pepper diced
• 2 whole Carrots, Peeled And Diced
• 2 stalks Celery, Diced
• 1 whole Jalapeno, seeded and Finely Diced
• 3 cups Vegetable Broth
• 1 can Plain Tomato Sauce
• 3 oz Tomato Sauce Paste
• 1 can diced Tomatoes + Chiles
• salt
• 1 teaspoon Ground Oregano
• 1 Tablespoon Ground Cumin
• 2 Tablespoons Chili Powder
• 1 can Kidney Beans, Drained And Rinsed
• 1 can Pinto Beans, Drained And Rinsed
• 1 can Garbanzo Beans, Drained And Rinsed
• 1 can Black Beans, Drained And Rinsed
• 1/4 cup Masa or Regular Cornmeal
• 1/2 cup Warm Water

In a large pot, heat the oil over medium heat. Add the garlic, onion, 3 colors of bell pepper, carrots, celery, and jalapeno, then cook for about 5 minutes, stirring occasionally, until starting to soften. Add the oregano, cumin, chili powder, and salt. Stir and cook for a few more minutes.

Pour in the broth, tomato sauce, and tomato + chiles. Stir, bring to a boil, then reduce the heat to low, cover, and simmer for 30 minutes. Add the beans, stir, then cover and simmer for 30 more minutes.

Mix the masa with the warm water and stir it into the pot. Simmer for 15 more minutes. Taste and adjust seasonings.

Serve with cilantro. Non vegans go for cheese or yogurt