Update on Solar Oven

Dear Fellow Inventors,

Before I left on vacation for France, Elliot and I were working on polishing aluminum. While I was gone, he covered posterboard with aluminum foil, and achieved our best success to day.  With those imperfect panels, the concentrator produces enough concentration to be painful on the palm of the hand after about 15 seconds.

My first reaction to this was to despair that it has taken us so long to get this far; then this changed to joy that we were making progress.

We then attempted to cook a tablespoon of scrambled egg in a glass jar.  The jar got hot---painful to the touch, and hot enough that the cap leaked, probably from thermal expansion.  Unfortunately the egg did not solidify.  This is rather sad.

One of the problems that we had was that it was cumbersome to hold the oven chamber in place.  We were using duct tape, and it never really held on correctly.  Aiming the concentrator required us to sit their and hold it and was somewhat error prone.

After some consultation, we decided that, although we want to stick to an "Agile" development methodology, the time had come to us invest in a better frame so that we could hold a cooking chamber in place.  This would allow us to perform repeatable cooking experiments, which are too cumbersome at present.

Our basic system now consists of two modules: the concentrator, and the oven frame.  I personally suspect we will have to think of the interface between the two as a third module.  The purpose of the modules is to be able to change one without having to change other.

We believe the concentrator, which should produce 16 suns of concentration, is producing less than 8, and I personally believe we are not utilizing all of that due to the interface.  However, the new frame should allow us to test this more easily.

So, after making up this plan, I spend the day (about 7 hours total, including shopping time), constructing the frame shown in the photographs below. This cost about $35 for the plywood and the bridging wood, and a small number of 1.5 inch and 1 inch wood screws and 4 1/4 inch bolts. 

The basic design of the frame is based on that of the Dobsonian Telescope frame.  I built such a telescope about 10 years ago with my son, although I through the frame away.  This is a well known approach to "aiming" an object of approximately this size.  The relationship to astronomy is obvious.  We might someday complete the azimuth and altitude mount, but for today I just built the semicircular base that our concentrator could be directly mounted to.  Hopefully this base, when propped up with a stick since I can't build a counter-balance until we build a cradle for the frame, will allow us to perform methodical cooking experiments.

Here is the concentrator mounted on the frame.

Looking down into the concentrator with aluminum and poster-board panels.

The cocnentrator bolted to the frame

These are cut out to allow us to insert a cooking chamber into the target area of the concentrator.

View From Beneath

View from Beneath looking through concentrator, showing bridging.

Mason jar as cooking chamber (would need to be raised an inch or two to be in target area.)

Mason jar at target area---hopefully this is the view the sun will see!

The Feel of France

Dear fellow inventors,

I have not posted in sometime because I have been on vacation in France, visiting Paris, Burgundy, and Nimes.

Elliot and I are continuing to work on the solar oven.  I purchased a very powerful polisher, which should allow us to achieve a highly reflective surface to complete our current solar over design in the next few weekends.

In the meantime, for those of you who may care, here is a little essay, a "trip report" if you will, about France.

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The Feel of France

France is full French persons. More than the gently rolling hills, the palaces once used by kings and now used by tourists, the towns grown organically around old walled cities, the remaining forests, the sheepfolds and white Charolais cattle glowing in the sun, the 150-year-old stone barns, it is the French who make France beautiful.

The French are beautiful because they pay attention. They eat with enthusiasm and savor, and so they do not eat too much. They have elected a 35-hour work week, and so they have more time to pay attention to their lives. The women select their clothes, even simple t-shirts, carefully. Fathers pay attention to their kids in public. Sales people pay attention to their clients. They all pay attention to tourists.

The food is not cooked better than the food in my city of Austin, Texas. I don't believe the French chefs are on the whole smarter or harder-working than ours are. However, eating is better in France. In the first place it seems clear that food production is less factory-oriented than in America, based on the herds and flocks you see in the fields as you drive along, evidently eating the summer grass, and the great bales of hay drying for winter. The signs directing to you “country tomatoes” at low prices seem to be in direct competition with the markets that sell the same, evidently local, produce. That these markets are a far more important part of most peoples lives is of course aided by the fact that their towns are based on walking and not driving, and of course it is more efficient to have a market stand when thousands of people walk by each morning and nobody has to worry about parking.

Perhaps more importantly, the French pay attention to meals. The meals are better, even if the individual food items are the same. The French give you just the right amount of food. The menu design of several small courses encourages a leisurely enjoyment of a variety of foods. You don't just “have a steak”, you have an apéritif, an entrée , a steak, a glass of wine, and a desert. In short, you have an experience. The steak is half the size of what we Texans consider a serving, but it taste twice as good and weighs have as much in the belly. It is “just right” more often in France.

Someone decided to plant that line of sycamores along that roadside 80 years ago, or decided to place the road along them already, and they were paying attention when they did so. Someone decided to plant geraniums next to that rose. If France seems a little less manicured than England, it seems a little less overwrought and a little more just right.

Americans sometimes think of the French as rude and lazy, which seem patently absurd. Of course, I prepared for my visit by not being rude and lazy myself—I learned enough French to say that I don't speak French well, I learned how to great people, understand numbers, and say please and thank you. I always asked if people spoke English before throwing it at them. Usually their English was better than my French, but we always met on equal terms, both struggling to communicate in a foreign language. Of the hundred or so people I interacted with, everyone single one of them was as helpful as they could be, with the exception of the two gentlemen who attempted to pickpocket my iPhone on the Metro, and they had the courtesy not to strike or stab me.

The idea that French are lazy must come from the 35-hour work week. I think is is better to say the French have elected not to work at making money as much as Americans have elected to do so. This is a cultural choice. The French seem to believe what we say: “Their is more to life than making money.”

It is impossible to be lazy and ride bikes as much as the French do. I am not widely traveled, I'm sure there are places where bikes are used even more, but France is a very bike-friendly place. Even in Paris, there are people riding to work, and they seem to be treated with kindness and respect by the automobilists. In America we treat biking as an activity distinct from transportation, whereas the French seem to a see a continuum of cycling, from cars diverting carefully around an old gentleman barely rolling along to the Tour de France. A woman riding her bike to work in a long skirt is not as colorful or flashy as a rider in a bright racing jersey zipping by, but caresses the eye rather than striking it.

The Eiffel Tower is beautiful because of the attention paid to detail in its design. Its beauty derives from its just-right proportions, its just-right level of complexity, its harmonic balance of the bold and the delicate. Fontainebleau is beautiful because of its harmony, where as the Louvre is excessive—but then, just as we did, they got rid of the source of excess, didn't they?

America got lucky after World War II. The action has been in America since that time, though the USA seems to be less dominant now. I believe we and the French have a great deal in common intellectually. Certainly, we have embraced the French invention of parkour as enthusiastically as the French have embraced Hollywood and rock n' roll. In science, art, literature, and above all philosophy, we and French are really kindred spirits. We should try to give the French some of our brash, loud energy and take from them some of their balance and harmony.

I left France inspired to live a little more harmoniously, to try to make things a little more beautifully, to concentrate a little more on fewer things, and to return.