Kaleidoscopic Solar Oven / Cooker

by Curlydock

One of my earliest installments dealt with the theory of the best angle to use with the reflecting planes of the solar concentrators of the Box-type solar oven. Since then, I have come to prefer what I call a “Kaleidoscopic” type solar oven.

I feel I have many reasons for this preference, but the most important is simplicity or ease of construction. Roughly speaking, the 3-D description of a Box-type oven takes about 20 vertexes and 32 lines. For the Kaleidoscopic type, it is 8 vertexes and 11 lines. So the Box type is about three times more complicated than the Kaleidoscopic type.

image 92

Image 92 shows the Kaleidoscopic oven I used to bake many loaves of genuine sourdough bread over this past summer.

image 91

Image 91 shows a not-fully-risen loaf before baking. I consider it fully risen when the top of the loaf reaches the top of the bowl. The bread bakes in the oven-proof glass bowl which sits in the oven cavity. The cavity is detailed later.

image 82

image 83

Images 82 and 83 show a finished loaf.

image 89

Image 89 looks into the front of my Kaleidoscopic oven. Most of the essential parts are seen. Missing is the glass bowl that would sit inverted over the top of the black lid. The oven cavity is shown in position and ready to receive the bowl of dough.

The reflective concentrators are in four planes. Two that I will call R1 and R2 form a vertically hinged unit that opens like a book and sits at a 60 degree angle. The hinge for R1 and R2 is made with strapping tape. The oven cavity just touches R1 and R2 and sits on R3, which is a separate unit the shape of a triangle.

The R3 angles are all 60 degrees and the length of each side is three times the diameter of the oven cavity. R1 and R2 are as wide as the sides of R3 and considerably taller than that.

R4 is also a separate piece and extends from the open edge of R3 as if it were hinged horizontally to R3. It could be permanently hinged but I feel there is no need for it. A pole pivots from the outer edge of R4 and fixes on the ground. It is used to set the angle of R4 so that the oven cavity is the brightest you can make it. If the wind is not blowing, gravity and the angle adjustment pole will keep R4 in place.

If there is wind, then I fasten all the sail-away reflective panels to the table with shoestrings. The cardboard from which R1, R2 and R4 are made is reinforced along bottom edges with narrow wood strips and package sealing tape. The shoestrings go through holes punched in the cardboard, around the wood strips, and through the mesh of the table top.

The weight of the oven cavity keeps R3 in place.

When the wind is very strong I use sandbags to hold down the table legs.

Here is a diagram comparing the Box and Kaleidoscopic type solar cooker / ovens and labeling of the concentrator panels I have been describing:

oven types diagram

The Box type has only one side glazed. That is the side where the solar flux enters the box. The other five sides have to be well insulated to keep the heat in. The maximum reachable temperature will depend a lot on the effectiveness of this insulation and the quality of box construction.

The Kaleidoscopic type does away with this particular need altogether by making all sides glazed. So, solar flux would enter all around the oven cavity, in theory. In actuality, this will not be perfect. The reasons have to do with the positioning of the oven cavity among the reflecting walls. Some positions are better than others.

Here is a detailed semi-exploded diagram of the oven cavity:

oven cavity diagram

The oven cavity works like a green house to trap the heat from the focused solar flux. The ideal would be a series of concentric spheres. The outermost sphere is transparent glazing that passes light. The next sphere is an insulating jacket to keep the heat, for which a vacuum would be best but air is easier. The next inner sphere is flat black metal which absorbs light and converts it to heat. This heat ideally accumulates in the central sphere where the food cooks in its container.

The ideal is approximated here by the use of oven proof glass bowls and a stainless steel metal mixing bowl.

The outermost sphere consists of two glass bowls: (1) is inverted on top and (4) completes the bottom half.

The insulating air jacket is made by suspending the metal radiation absorber bowl (6) on a ring (7) cut from a double layer of heavy corrugated cardboard. The ring rests on the lip of outer glass bowl (4). The lip of the metal bowl (6) makes a snug fit in the ring (7) so that the metal bowl will not fall through. The metal absorber does not touch the outer bowls anywhere. It only touches the cardboard ring. The ring and air jacket are poor conductors of heat. They confine most of the heat to the cooking area.

The metal radiation absorber bowl is a stainless steel mixing bowl painted flat black on the outside with the kind of paint that withstands heat, or the paint you would use on a charcoal grill. Let the paint dry, cure under heat and air out for several days before using it for cooking. You probably would not like paint flavored bread.

I was lucky in finding a black metal cooking pot lid (2) that just fits over the lip of (6) and rests on ring (7). There are cake or pie tins that might also work if painted black on the outside.

Bowl (3) holds the food or bread dough. It does not have to be transparent. I have been using oven proof glass but recently found a ceramic bowl that should also work. Another metal pot identical to (6) would fit snugly and maximize cooking space and thermal conduction to the food, but I have not tried that yet. In fact, I suppose you could do without (3) altogether by putting the food in the radiation absorber bowl (6). But, since (6) is not easy to get on and off ring (7) and the cardboard of (7) should not be washed or get wet, I decided to use another bowl to hold the food.

On my wish list is some kind of thin wire handle to make food bowl (3) easier to get in and out of metal bowl (6). The handle would need to quickly and easily connect and disconnect from the edge of the food bowl and not compromise the thermal seals around the edges.

The whole cavity needs to be somewhat elevated so I put it on a transparent pedestal made by inverting the smallest glass bowl (5) near a corner of the bottom reflector, R3.

Most of the glass bowls I found and purchased as a nested set. I think perhaps the largest, (4), was not part of that set and had to be separately purchased, but I am not sure.

Why Kaleidoscope

To study the effect of the focal positioning and the angle of R1 and R2, etc., I decided to research the geometrical and mathematical aspects of multiple reflections in mirrors. From that, I realized the kinship between kaleidoscopes and this type of solar cooker. The next pictures should make the relationship obvious.

Fascinating as it was, I thought it might take too long, so I did an empirical study with a scale model instead of the exacting thought experiments. I gathered some pieces salvaged from a broken mirror (never throw anything away), tape, and construction paper. Also, I borrowed a large bead from a trusting and tolerant friend.

Image 74 is an overview of the apparatus:

image 74

The bead stands for the oven cavity or focus.

The mirrors that hinge on a vertical axis stand for reflecting planes or solar concentrators R1 and R2. R3, seen here on the bottom, will be moved in and out. R4 is not shown here but will be seen later.

image 57

image 60

image 61

image 62

Images 57, 60, 61 and 62 show how the number of reflections of the bead increase as the angle between R1 and R2 decreases. This inverse relationship says to me that the narrower this angle the better as far as solar flux concentration.

Surely, the more images of the bead (oven cavity) the sun “sees” then the more solar flux will concentrate on the bead.

But there are several trade-offs.

As you can see, the ring of bead reflections gets gradually larger as the angle decreases. To compensate for this, the sizes or areas of R1 and R2 need to progressively increase. At some point R1 and R2 are too large and cumbersome.

image 63

Image 63 shows how adding one more mirror, representing R3, doubles the number of bead images. Note how one of the images is lost because it is shadowed or hidden by the actual bead.

image 73

Image 73 shows how images are partially obscured when the bead is not elevated:

This is the reason that the oven chamber is elevated a bit by bowl (6).

image 72

Image 72 shows how the bead image count can be at least doubled yet again by adding the mirror that stands for R4. But, as the count and complexity of reflections increase, more and more images are obscured. There seems to be a threshold of diminishing returns.

image 66

Image 66 shows the concentrators at work. I used flash, which, I belatedly realized, is probably not good for a digital camera in a setup like this. Fortunately, perhaps most of the energy focused and dissipated on the bead instead of getting back into the camera lens.

If bead were bread, it baked.

How I Use the Kaleidoscopic Solar Oven

I use an angle of 60 degrees between R1 and R2. There may be a better angle. I have not tried others yet. I adjust the table orientation and the angle of R4 about once every 15 or 20 minutes. This needs to be done more often when the sun is high in the sky.

I frequently measure a temperature of 280 F between the top glaze bowl (1) and the lid (2), depending on the time of day. Morning hours, with the sun at a lower angle, seem to make the oven hotter than do the noon hours, probably because of the reflection obscuring effect already mentioned. Elevating the oven cavity even more when the sun is high in the sky might make the oven even hotter, but I have not needed to try that yet.

Either time of day works fine for baking my bread. The recipe for one loaf of sourdough calls for 45 minutes at 350 F in my conventional oven. I can bake 3/4 of that recipe in the Kaleidoscope solar oven in around 90 minutes. The crust browns nicely, especially on the top.

You might be tempted to let the finished bread cool just a little bit in the oven. But don’t do that. And don’t be fooled. The oven gets very hot. Be careful not to burn yourself.

While the oven is cooking, the moisture escapes as steam. As soon as the oven starts to cool, that moisture condenses on the lids and runs down to collect on the corrugated cardboard ring. The cardboard ring may dissolve if it gets wet. But, it can withstand the highest temperatures of the oven just fine. The high temperature helps keep the ring dry. As soon as I finish baking, I dump the bread on a rack to cool.

After a bit of practice, you can tell when the bread is finished baking by how it smells around the solar oven. Also, you will begin to see condensation on the inner side of glass bowl (1) when the bread is ready.

Outside of baking sourdough and cornbread, I have not yet cooked other things in this particular oven / cooker. I wonder if the condensation will be more of a problem if, for example, I make soup. I don’t know yet.

A Note on Construction Technique

Many instruct builders of these types of ovens to glue the aluminum foil to the cardboard with diluted white glue. I no longer do this.

I believe it is sufficient to bend the foil around the edges of the corrugated cardboard and fasten it in the reflective plane about every square foot using brass plated paper fasteners. Insert the fasteners through small holes prepared with a knife blade. These fasteners can be found where you get office supplies. They look like tacks with points that can be spread apart. This is much easier than working with glue. It is easy to repair.

But the main reason I do it this way is that the foil is easily removed from the cardboard when time comes to recycle them both. My red worms can eat the cardboard but the foil might not be good for them and would not be wanted in the vermicompost.

I do use white glue or carpenter’s glue to bond cardboard to cardboard where a panel needs more strength or a flap needs to be made rigid.

image 93

Insectary Plants and Beneficial Insects by Curlydock

My recent surge of interest in insectary plants and beneficial insects found me in the garden with my camera. I spent about an hour taking pictures of any insect I saw and noting the plant each insect was seemingly associated with.

I did this on September 8, 2007, in my small experimental urban organic garden located in Jefferson County, Kentucky, USA. These are a few of the pictures.

I am not expert at insect identification. If you think my guesses or any other data I give are not correct, please feel free to leave a comment with your own opinion.

To avoid the use of chemical poisons, I hope to eventually have enough of the right kind of insectary plants. The theory is that the right plants will attract the kinds of good insects that predate on the bad insects. Bad insects do bad things like chewing big holes in my broccoli leaves, for example.

I understand that one should not attempt to wipe out the bad bugs altogether. Enough of the bad bugs should exist to feed the good bugs so the good bugs will stay in the garden and not have to leave in search of a meal. While this is not mechanically efficient, an argument could be made that mechanical efficiency is not a sustainable way to relate to the environment.

One should seek the productive balance innate in stabilized diversity and then not sully that balance with pollution, poisons, and the exhaustion that comes from expectations of competitively efficient exponential growth. The correct balance can be productive enough to sustain the lives of farmers and those who depend on farmers for meals, were the world not obsessed with greed.

Since the good bugs burn a lot of energy in their hunt, they need the nectar and pollen of flowers to help sustain that energy. To that end, some plants are better than others at attracting good bugs. The shape of the blossom might help or hinder the access of a particular insect to the pollen and nectar the plant offers. Also, some plants can attract aphids or insects that are specific to that plant and will not harm garden plants but will provide meals for the good bugs. Not all plants bloom at the same time, so in a diversity at least one plant will always be supplying the good bugs with what they need. It is also possible that the wrong plant would attract bugs bad for the garden or host diseases also bad for the garden.

So, it can get complicated. I need to study hard to find the right combination of insectary plants to grow in or near my garden. On the bright side, the complexity of the study is deep enough to keep one interested for a whole lifetime. One need not study rocket science to keep from getting bored. How nature grows diversity will suffice.

bumblebee

Image 417 is perhaps a bumblebee. Some think it is, instead, a carpenter bee. They look a lot alike but I understand the abdomen of the carpenter bee is slick instead of hairy. This insect is beneficial because it pollinates flowers. The bee rests on the flower head of Garlic Chives (Allium tuberosum). The bee was so still I thought it might be dead or asleep. Or drunk? When I finally nudged it, it moved sluggishly but it never flew or even buzzed all the time I was there.

image 498

Image 498 shows what seems to be a different type and much smaller bee. This one is on a marigold blossom.

image 398

Image 398 shows what I believe is a soldier beetle called Pennsylvania Leatherwing (Chauliognathus pennsylvanicus). Many say it is beneficial but at least one said this insect’s value may be exaggerated. Even if it does not eat bad insects, at least it seems to be a good pollinator of Garlic Chives, for there were a lot of these soldier beetles there.

image 490

Image 490 may be a Green Bottle Fly, I am not sure. Green Blow Flies are supposedly associated with decaying flesh, but there were a lot of these really interested in the Garlic Chives. Nothing smelled dead.

image 437

Image 437 may be what is called a “Question Mark” butterfly, but I am not sure. It rested close to corn and beans.

image 460

Image 460 shows a wasp that repeatedly returned for a drink of water from the little watering hole. Many wasps are beneficial because they predate on bad bugs.

The watering hole is made of an overturned garbage can lid. I keep it replenished with water from the rain barrel. I change the water at most after every couple of days to keep mosquitoes from breeding in it and to keep it from stagnating. I had hoped the watering hole and an adjacent shelter hole would attract a toad, but I have not seen a toad yet. I did see a blue-tailed lizard not too far from the water, but that was much earlier in the year.

image 378

Image 378 shows, I believe, the eggs of a Leaf Footed Bug or Stink Bug. The eggs were attached underneath a leaf of broccoli. I did not see any adults this day, but I have seen them before. They have hind legs that are flattened like a spatula or leaf. Some of them may be beneficial, sucking on caterpillars of bad bugs. But I suspect the ones around here are only interested in sucking juice from the broccoli.

image 379

Image 379 shows a moth caterpillar that might be an “Inch Worm”. It has been feasting on the broccoli and a bad type. I hope someday I see a beneficial insect feasting on it.

image 383

Image 383 is a young, I think, type of Harlequin Bug. They also eat the broccoli.

image 433

Image 433 is a Garden Spider, (perhaps Argiope aurantia). I understand that these spiders need a source of water. This one was about 4 feet from the watering hole and very near the corn and beans. I believe spiders are, on balance, beneficial.

In conclusion, many insects could be seen in one hour in my organic garden. Some were beneficial and some were not. Many pollinators were seen. Many destructive insects were seen. I would like to see a lot more beneficial predators. I recently transplanted some Golden Rod to my garden. I found it on a farm in an adjacent county. I have heard that Golden Rod is a good insectary plant. That it aggravates hay fever and allergies is a bad rap and is not true, from what I have read. I plan to introduce more selected flowers in the future. When I planted the Garlic Chives (Allium tuberosum) I did it for food. I did not know it was an excellent insectary too, until I saw it in action.

Winter Window Garden

by Curlydock

Some months back, in November / December of 2006, I wrote several installments dealing with seedling identification. I sprouted seedlings and tried to keep a webcam record of them for future reference. The seedlings became spindly and were growing slowly because, I believe, of short winter days and little light.

I did not want to burn energy in lights and timers, so I left the mini-garden in the southern window to fend for itself. I did keep it watered with rain-water that had been slow-sand filtered. I also warmed the water a bit by storing a gallon or so of it by a furnace duct.

As the days got longer I noticed the plants began to grow more rapidly. A few weeks ago I harvested and ate a head and some leaves from the rapini. It was delicious.

Today, before I harvested and ate the radish I took some webcam shots of the radish and the chard. Someone frequently visits this blog looking for pictures of the plants. So, here are a few more plant pictures.

day 110 white hailstone radish

Above is the white hailstone radish. It has been 110 days since the seed was planted. Below is the rhubarb chard. It was planted 82 days ago.

Day 82 rhubarb chard

The pots they grow in are about 3 inches cubed. The potting medium in each is half peat moss and half my vermicompost. Each pot also has about 2 tablespoons of crushed eggshell.

The plants are very delicate. They don’t get strong breezes so their stems have not grown stiff. When I moved the chard to photograph it, it fell over. I propped it up a with a ball of tissue.

When I removed the tissue I noticed the tissue was damp, and the odor I cannot describe except to say it was heavenly.

Drinking in that odor of healthy organic compost in communion with the chard roots reminded me powerfully of what we have lost in our culture. This is the odor of a small organic farm. It is the odor many more of us should be familiar with. It is the odor more of us must become familiar with if there is to be a future for us on this planet.

This odor energizes an intuition of what is right and what is wrong. It puts me out of reach of the propoganda of pundits, thinktanks, preachers, bad teachers, blustering talk show bloviators, and all apologists for greed who seek to influence and control us. It puts my mind and heart on a firm foundation. Let them spin and grin, with their fingers crossed. I know which side I’m on. They won’t fool me again.

Simplest Radios

by Curlydock

The simplest radio

receivers require no batteries, gasoline, coal, oil, nuclear, wind, geothermal, tidal, or solar power.

And, they are indeed simple. Using them and building them out of parts found in the junkbox or scavanged from yard-sales will not hurt the planet and will not make Greedy Gates even richer.

I built this one for a recent experiment. It has only five electrical components. The only power it requires exists in the signal it receives. In our metro area (Louisville, Ky) in one afternoon I received eleven stations loud and clear. These transmitters were all local and within about a twelve mile radius. Their powers ranged between 500 watts and 50 Kilo-watts. The 500 watt station is roughly 5 miles away.

These radios are variously called crystal sets, crystal radios, or foxhole radios. In the “foxhole” variety, the home-made simplicity includes the signal detector, which is a razor blade and piece of pencil lead!

The All-Powerful Antenna

For this type of radio to work well, every consideration must be made to conserve the precious power that arrives in the signal. This typically requires a very long and high outdoor antenna and a good ground connection. This antenna is a wire between 30 and several hundred feet long. The ground connection can be a cold water pipe (but only if it is metal into the earth) or a metal rod or pipe driven 4 to eight feet or so into the earth. Good performance depends on a good ground connection and such connections are sometimes hard to come by. For safety, one should also install some kind of lightning arrestor and disconnect the radio during bad weather. Also, one should install the antenna well clear of power lines. All this may be difficult to impossible in a metro environment.

Until this experiment,
I believed crystal radios could not be made portable or operate effectively with an indoor antenna. Now I know otherwise. You still can’t stick it in a pocket, but you can easily carry the radio and antenna around while you listen to a station.

Given the appearance of the antenna, you would attract a lot of attention outside. Whether attracting attention is good or bad depends on you and your needs and the particular setting, I guess.

Anyway, here is a picture of the crystal set and antenna I built and used in this experiment:

crystal set used in experiment

It sits in the comfortable chair, for scale, next to the special loop antenna. The loop antenna has a 32-inch outside diameter. This installment is really about the antenna, because that is what made the radio able to receive as well as it does.

The antenna is not as heavy as it looks because the bulky part is cut from thick sheets of styrofoam insulation, which is mostly gas and therefore light. The rings are glued like a sandwich over the sector fingers, which were made of scrap pieces of a wall covering that resembles pressed fiber board (like some clip boards are made of). The antenna can easily be lifted from the pvc pipe support and carried around slung across your shoulder, all the while supplying signal to the radio.

Other materials can be used. In other versions, I used bamboo chopsticks taped in pairs on either side of wood popsicle sticks, creating the slot that the cable is woven through. I have also cut the whole ring and set of sectors and slots from large sheets of cardboard. To strengthen large diameters, you might want to use white glue or flour paste to build up several layers of cardboard. Use styrofoam, plastic, wood, cardboard, pvc pipe or plexiglass but keep the use of metal in the antenna to a bare minimum. Even the non-metal structure should be kept to the minimum needed for support of the wire. For example, if you use large sheets of cardboard, cut out the middle so that it is a ring instead of a disc. Discarding anything that is not needed in the viscintiy of the antenna will improve it’s quality. Ideally, if you can figure out a way to support the wire on nothing but air, more power to you (and to your radio)!

The weave of the cable is important. Here is a close up showing how this weave was accomplished on this antenna:The weave in the sector slots

This neat alternation is possible only with an odd number of sectors. Use 5, 9, or 11 sectors, but not 6, 10 or 12, etc. No, it is not numerology. I am not superstitious. Try it and see!

The reason for this weave is that it keeps the individual turns of wire separated from each other. The separation is needed because if the wires lay close together, as in a close-wound coil, something called capacitance will build up with each added turn to such a degree that it spoils the quality of the coil. I know it sounds like I am just pulling this out of my…, but, believe me, it’s true!

The wire

I used in the antenna was about 90 or 100 feet of cable from a spool labeled: “100-Ft. (30.4m) Telephone-Station Wire 8-con.(4 twisted pair) 24-Ga. Solid Color-coded.”

It was copper wire.

I first wound the whole antenna and then went back and cut each turn.

That can be done neatly if you cut all the cable on each side of one particular support slot but on only one side of the plane of the disk. That sounds complicated, but however you end up with a coil of eleven turns with one tap per turn and an extra tap for the odd end is ok with me.

The eight individual wires in these cuts were then cleaned of insulation and soldered together. The ends were then re-joined as they were before they were cut, along with a wire from this joint that terminated at a tap made of a tiny brass nail embedded in a piece of plexiglass. Each end of the original cable was treated the same way. Since the antenna has eleven turns, there are 12 taps.

Here is a close up of the taps:

eleven turns and twelve taps

The reason for all those taps is that it offers the most flexibility in choosing the way the antenna is connected to the other components.

The reason for connecting the eight individual wires in the cable in parallel for each turn is that the cable becomes a rough approximation of a special kind of wire called “litz” wire that is ideally used for this sort of purpose but is expensive and hard to come by. At the very least, wiring our telephone cable this way reduces resistive power losses by increasing the copper conductor cross section.

You could also use coaxial cable of the type for connecting between TV or FM antennas and their equipment. It doesn’t matter exactly what kind of coaxial cable as long as it has a large diameter and a good shield. Then, ignore the center conductor and use only the shield when you make your taps. The copper cross section in the shield is much more than that of the center conductor. You could connect the center conductor to the shield at each opportunity but it will probably not matter much. The signal will all want to flow in the shield anyway, due to something called the “skin effect”. No, I am not making this up.

Now is a good time to introduce

The schematic:
schematic for crystal radio
See the taps? There are two sub-circuits to connect, each having two alligator clips.

Where the variable capacitor is connected determines the tuning range. Select taps enclosing more turns to lower the minimum tuning frequency. Connect the capacitor across fewer turns to tune to higher frequencies. I have found the whole AM broadcast band is covered with two taps.

Where the germanium diode circuit is connected affects the selectivity, or the ability to tune one station at a time. It also affects signal loudness because the different taps affect what is called “impedance matching”. In addition, there is a transformer action, but the actual transformed output voltage will depend on the “Q” or bandwidth. The theory is complicated but fortunately the best tap points are easily found by trial and error (as long as you don’t have to keep cutting and soldering over and over again. That is the beauty of having each turn with a permanent tap.)

Generally, the radio works best when the detector circuit taps between a number of turns equal to about a third of the number of turns the capacitor is tapped between. But the best position can change if you change the type of detector or earphone.

Speaking of earphones,

the kind you get with just about any electronic equipment these days will not work. The earphone has to be a high-impedance type. A few places still sell them. If you can’t find one, look for an older telephone. Sometimes the receivers on them work passably well, indeed very well if you can find a matching transformer. Details about how to fix these sorts of problems can be found elsewhere on the Internet. Just do a search on “crystal set” or “crystal radio”. It is a remarkably popular topic.

Here are a couple of shots of the box housing the variable capacitor, resistor, germanium diode and various binding posts. I took a bit of artistic licence with one of them.

crystal radio

close up of crystal radio

If you build one of these I would like to know your results. Just post a comment here to that effect. I am particuarly interested in knowing how this design functions outside of the city. How many stations will it receive in a non-metro environment?

Also, if you have any questions about the design feel welcome to post them here.

Frankly, I am looking forward to spring so I can put away my winter projects and get back to gardening.

Sourdough Starter as Ecological Model

By Curlydock

Ever wonder what your sourdough starter gets up to when you are not looking? I spied on mine with a web-cam for about a day. Now I know the shocking truth of its secret life and will show and tell all in this installment.

Why care

about this? There are several parallels between what happens when you feed your sourdough starter and what has happened on this very planet Earth when the human population began to explode.

In both cases, there is a population of living things in an environment that is limited in size and resources.

The sourdough starter is populated with yeast and bacteria in symbiosis. It needs flour for the population to grow and will consume it all if you do not replenish it. Then, there is a die off or crash in the population as a result of starvation, resource exhaustion and poisoning by the accumulation of waste material. Sound familiar?

Earth is populated with people, all the species that people depend upon, and many species relegated to “weed” category, thought of as expendable because we have not yet figured out how to exploit them. Ecologists and those who understand the need for organic farming methods are among the precious minority who value species diversity. As much as we like to think we can dominate nature, the real truth is that we are also symbiots. Our determination to dominate instead of live in harmony is driving the planet and all its populations into a dead-end.

The sourdough starter cannot grow out of it’s jar. (Well, it can but is not likely to find more flour if it does.) The human population cannot leave this planet in any significant numbers any time soon. (And, even if it does, how much organic coffee can we grow on the moon?)

Perhaps the sourdough starter can teach us something about mindless consumption and procreation. “But”, you may protest, “Unlike yeast, people have minds!” I will counter: “A person in a state of denial behaves automatically and just as if they do not have a mind.” Mindless consumers. Purchase what you don’t need. Throw the left-overs in the gutter. Make babies like the world was going out of style. Well, perhaps it is.

The sourdough starter needs flour. Unless you replenish it, the starter will consume all that is available.

The human population of Earth has developed a crippling dependance on oil and other limited resources. Even if we don’t run out of coal and oil, we cannot continue to use them because their use in this already over-populated planet is what is triggering global warming. So, discovering vast new supplies of cheap oil is no solution. In fact, it could aggravate the real problem. Irony.
Procedure

I mixed 54 g of flour with 103 g of water. To that I added 68 g of vigorous starter. Of that 225 g total mixture, I poured 122 g into a glass jar and loosely coverd with a plastic lid. The glass jar was placed in a temperature controlled chamber in front of a camera. The temperature was monitored and never significantly deviated from 79 deg. or 80 deg. F. For a period of about 12 hours, one picture was taken every 5 minutes, resulting in 150 images.

Results

I selected eight of the 150 images to put here. In each image, you will see that I have inserted a set of numbers at the top center. These numbers represent the duration, in hours and minutes, at the time the image was recorded. So, the first image is “00:00”:

00 hours 00 minutes

The next image is after 2 hours and 26 minutes have elapsed:

snapshot-20070105-140039.jpg

At 02:26 you see the normal layer of “hooch” forming. I did not know until I did this experiment that it first forms at the top of the starter. You also see the bubbles of gas forming in the starter, causing the starter to “rise” as it would when used to leaven bread dough. The hooch and gas are the waste products from the yeast and bacteia, the populations of which are beginning to grow rapidly.
At 03:16 the starter has risen a good bit. The hooch layer is
snapshot-20070105-145044.jpg

getting pushed to one corner as the center bulges.

At 03:26 there is another unexpected phenomenon.

snapshot-20070105-150044.jpg

The corner where the hooch was is foaming violently. I say violently because this all took place on a time scale of 5 or10 minutes. This is after almost an hour and a half of liesurly, predictable rise in the starter volume and number of gas bubbles (correlate with population of micro-organisms). I watched this occure on the monitor, bemoaning the fact that all this excitement would be lost to posterity because I had decided to record only one image every 5 minutes. I would have needed a couple of images a second to capture all this short-term activity, which began suddenly and without warning and did not last long at all. I gripped the edge of my seat and practically left greasy nose-marks on my monitor, wondering what this portended for my little microbe-cosm.

At 03:46 the foam is leaving. Where did the hooch go?
snapshot-20070105-152048.jpg

If you look closely you can see the hooch is now all the way at the bottom of the jar.

At 06:26 you see you can’t keep good hooch down.

snapshot-20070105-180107.jpg

Now there are three distinct layers. Under the hooch is a layer of starter that seems to be inactive because there are no bubbles in it. You can’t see it in a few images, but I can tell you it was still very active. Small chunks and particles were seen both rising and falling in the hooch layer. Since the bottom layer was growing, it must be that more was falling than rising. Does this remind you of the economy and the extinction of the middle class?

At 07:01 you can see the first settling of the top layer.
snapshot-20070105-183612.jpg

This tells us that the yeast and bacteria are beginning to die off. They have used up their resource (flour) and are now starving and succumbing to the poisonous effects of their waste products. It looks like the peak occured a bit after six hours in this experiment.

At 14 hours and 30 minutes I ended the experiment.
snapshot-20070106-000205.jpg

The top layer is at its lowest level since its peak. Once it started falling, the fall was pretty monotonous. I could have let it run longer but it had been a long day and this felt very much like the end of history.

Conclusion

Can we take any macro lessons from this micro-biological model? There are some important differences. Our planet, unlike the starter jar that got only one charge of flour, is being re-charged daily with “free” energy from the sun.

The trouble is, we have not been living within the energy budget of the sun since technology allowed us to exploit oil and greed made it inevitable. The energy density of “black gold” cannot be matched by solar, wind, geothermal, etc. Nuclear has a waste problem and the likelihood of catastrophic accidents increases with time and the number of reactors in use.

We may be running out of time to reverse the toxic byproduct of burning fossil fuels: global warming. It may be too late. It could accelerate tenfold or more without warning (remember the foam and the inversion of the hooch layer happened catastrophically). Indeed, there may be evidence of such an acceleration now, see: “Global Warming Already Causing Extinctions, Scientists Say“, by Hannah Hoag for National Geographic News, Nov. 28, 2006.

These sudden accelerations and unpredictable changes can happen in non-linear systems that are under stress. A little push in a certain direction causes changes that themselves add to the push and you get exponential acceleration. The hooch layer suddenly inverts. The die-off caused by global warming or the loss of oil as an energy source could also happen more quickly than predicted by the most dire of doomsayers.

Here is a very good reference for those interested in reading more on the topic of ecosystems that experience overshoot and sudden extinction: “Overshoot in a Nutshell” by David M. Delany.

Seedling Identification Revisited

by Curlydock

This is the start of my second attempt at seedling identification. This time I have a technique that should remove doubt about what sprouted.

Most of the unwanted volunteers from my previous effort turned out to be tomato seedlings. I fed a lot of tomatoes to the worms, so the seeds were still viable in the vermicompost.

I still want to keep the purported advantages of organic living soil so I still have not sterilized the potting medium. In fact, I am using the same pots I used before. This time, however, the seedling of interst is clearly flagged by a ring of newspaper around the seedling. Any sprout that is outside of that ring can be “weeded out”.

Day 6 Rapini

The ring of newspaper is the top rim of what I call a “tiny pot”. The tiny pots are made from 2-inch squares of newspaper wrapped around the end of a pencil. The small cylinder thus created stays intact when the end of it is crushed closed. The seeds are planted in the open end after the tiny pots are placed into the cells of an ice cube tray and moistened.

Sprouter Tray

To get one and only one seed in each tiny pot, I used a bamboo skewer moistened on the end. Small seeds adhere to the sharp end and larger seeds will adhere to the blunt end. Don’t stick the moist skewer into your packet of seeds. The moisture on the skewer is probably not good there. Sprinkle a few seeds from your main pack into another container and pick the seeds from the other container with the wet skewer. The smallest seeds may be repelled instead of attracted to the skewer at first, but they will soon give up their static charge and stick to it.

sprouter

The particular ice cube tray used was one with a five-by-twelve grid of cells. It makes very small round ice cubes. The tray is kept in a plastic shoe box with a lid to keep the tiny pots moist. I had to use a medicine dropper to remove excess moisture from the tiny pots. You want the tiny pots damp but not soggy. I would not have had to use the medicine dropper if I had drilled a small drainage hole in each of the ice cube tray cells.

Day 6 broccoli

The seeds are carfully selected and metered. Only one seed is planted per tiny pot. However, five seeds of the same type are plated in a row. That allows 12 different types of seed to be sprouted in one ice cube tray. Of the five seeds of one kind in any one row, only the largest or most vigorous sprout is selected to plant in the larger pots cotaining the medium of unsterilised vermicompost. The others are kept for a while in case the first one did not take.

Day 6 Chard

The sprout, tiny pot and all, is moved from the ice cube tray cell and planted into the larger containter of potting medium. Do this as soon as it is obvious the seed has sprouted. Leave enough of the tiny pot visible so it will serve as a flag saying “this is the one you planted”. Pull up anything else that comes along.

Tiny Pot

The tiny pots should decay and return to the soil eventually. The piece of paper they are made from is so small that the decaying paper should not significantly deplete the fertility of the potting medium.

Writers Who Inspire Curlydock

Wendell Berry, who wrote “Environmentalists Are Not Radical Enough”.

David C. Korten and his “FOR THE LOVE OF MONEY“.

David M. Delaney, who wrote “What to do in a failing civilization“.

Howard Zinn, in addition to his take on war in other of his work, speaks of hope in his “The Optimism of Uncertainty“.

Jason Miller, who wrote “American Capitalism and the Moral Poverty of Nations“.

Joseph C. Jenkins and his book on composting human manure “The Humanure Handbook“.

Jozef Hand-Boniakowski’s “Capitalism Requires a Great Depression“.

Published in: on December 14, 2006 at 10:17 pm  Leave a Comment  

Seedling Identification Concluded by Curlydock

Yes, I am already halting the project I started in the previous post.

It is a bit ironic, really.

I took pictures of seedlings growing in little pots kept on this winter’s windowsill. I wanted to refer to the images when I needed to identify what was sprouting in the garden. That way I could tell the difference between what I planted and any volunteers (also known as “weeds”).

Well, the volunteers are now vigorously raising their heads in my little pots. I cannot even be certain of the identification of what is growing on my windowsill.

Go ahead, laugh.

The mistake I made: I should have sterilized the germination medium. I did not.

I knew I should have sterilized it, but chose not to. I didn’t sterilize because I wanted to keep the reputed organic benefit of the microbes that are naturally in the vermicompost.

Also, long ago I observed seeds sprouting in the worm bin and in other compost piles I have kept. Since the vermicompost I used was about a year old I assumed anything that was going to sprout in it had already done so. Then, I reasoned, the sprouts died back because there was not enough light and the worms and microbes feasted off them as “green manure”. Apparently this was not true of the volunteers.

Perhaps some seeds are not fooled into germinating in what seems to be an ideal place to do so: the moist and nutritious old compost. Perhaps they wait for some clue to know the time is right, like a change in ambient oxygen or other chemical or momentary exposure to light. Perhaps they could sense the physical disturbance when I combined the vermicompost with peat moss and egg shells to make the potting medium. I really don’t know. If any reader has an idea or a clue, please post a comment.

The next time I attempt this project (and I probably will attempt it again) I plan to germinate the desired seeds in very small plugs of potting medium after baking the medium in an oven to sterilize it. That way the desired seedling will get a head start. Then, as soon as possible, I will plant the plugs in the very center of the small pot of unsterilized medium. It won’t matter what volunteers then because the desired seedlings are already identified. The volunteers can be uprooted as they appear.

Day 8 Seedlings by Curlydock

It is often difficult to know what is sprouting in the garden. Is it something I planted or a volunteer? I sometimes keep a volunteer, but not always.

broccoli seedling

As a winter project, I decided to germinate some things and keep track of them with a webcam. In future, I can look at the pictures to help me figure out what is in the garden.

broccoli seedling
I currently have 12 different seedlings growing in small pots in a southern window. If this works well, I may extend the project to include other garden plants and “weed” seedlings as well.

chard
These are my first pictures for this particular project. They are of the seedlings mature enough to display discernable details. The others are still too small.

radish seedling

If these pictures are of interst or use to you, please leave a comment to that effect. I am open to suggestions on how to do this better. I have some drawing talent and may someday include drawings of plants.

rapini
If you want to support my work, some of my art and photography is for sale in a gallery I just started.

My gallery is found at http://eulif.imagekind.com/bucolic .

Published in: on November 24, 2006 at 8:40 pm  Comments (30)  

Garden Irrigation by curlydock

Here is a garden irrigation technique I am experimenting with. I have been using it for about a year. The testing is incomplete because this year there was plenty of rain. I am hoping this technique will reduce the amount of water needed to water a garden.

Fig 1
At various places in the garden plastic bottles are buried upright up to their mouths. The mouths of the plastic bottles are wide enough to accept the necks of inverted glass bottles, such as a wine bottles.

fig 2
The bottoms of the plastic bottles are either cut completely off or perforated. The perforations begin or the cut is at a level about five or six inches below the surface of the soil. Whether to cut or perforate may need to be determined by trial and error. If the soil does not drain well, you may want to cut the bottom completely off. If the soil drains very well, then you may prefer perforations.

The idea is that the water should slowly permeate the lower root zone without saturating the upper root zone. The longish neck of the wine bottle insures that the water level will never rise above the mouth of the wine bottle, which should be about two inches below the surface. Once the water reaches the mouth of the wine bottle, the water will stop feeding until the water recedes below that level by gradually soaking into the soil. The water will be fed automatically at a rate that will be just at the rate at which the earth can accept it. None of the water should reach the surface.

My wine bottles are filled from a rain barrel. Hold fingers over the wine bottle as you invert it over the plastic bottle so that you don’t lose too much water. There is no point to getting water on the surface and, in fact, there are good reasons not to. The surface is kept damp only when seedlings are first germinating or their roots are not long enough to reach the level of the neck of the inverted wine bottle. After that, irrigate only with the wine bottles.

I am hoping the advantages of this method are:

1. Cheap. A friend supplied me with plenty of empty wine bottles. The plastic bottles are typically the ones that single-serving juice came in. They have mouths wide enough to accept the wine bottles without being cut down.

2. Re-use bottles that would have been piled in a dump or re-cycled.

3. I believe less water will be needed to keep the garden hydrated because the water is not poured over the surface where most of it would either evaporate or run off. Instead, it is fed directly to the deep roots where it is most needed. The upper roots of the plant are more for oxygen absorption than water or nutrient absorption. This technique should reduce the likelihood of drowning the plants by over-watering.

4. I think the drier soil surface will discourage slugs. I understand that slugs like things nice and damp.

5. Other irrigation methods are more of a tear-up. More of the garden surface needs to be dug up. The burying of long drip pipes would need to be done before the garden is planted. The wine-bottle method could be implemented after the garden is growing.

6. The wine-bottle method seems ideally suited for cold frames where it is especially important not to get things too damp. The frame will have a cover to keep rain off. The wine bottles full of water could be kept in a warm place. When they are used, they will help to keep the root zone of the cold frame plants nice and warm. The bottles could be warmed on a sunny windowsill or in a solar oven.

fig_3.jpg

If you try this wine-bottle technique for garden irrigation, I would like to learn of your results and what you think of the method.

fig 4

Published in: on November 6, 2006 at 9:46 pm  Comments (45)