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     "Robert Frost once compared education to bringing a load of hay to the barn. The teacher stands on top of the load and the student waits below, ready to receive neat little packets. Instead the teacher drops the whole load, shouting, 'Look out! Here comes education.'

     "...[W]hen I was learning how to teach...B.F. Skinner had reached the pinnacle of his influence and had persuaded us to divide education into neat little packets, each of which could be duly 'reinforced.' The timing of such reinforcement was thought to be critical - down to the second, lest for lack of swift praise the implanted learning become extinguished, like so many sparks failing on cold ground. Our method left no room for wonder or perplexity, no place for wisdom or sudden insight, because learning had been acclaimed a science, and science abjured whatever smacked of mysticism or romance.
" In teaching, we are too often persuaded to be gentle, fearing that we shall damage our children if we immerse them in dissonance or perplexity. We accede to the argument that each successive generation faces increasing complexity in life and so deserves greater sympathy and support to cope with the mounting difficulties that assault from every side - recession, divorce, pollution, addiction, nuclear holocaust. We may argue that young need...clarity, structure, simplification, reward.

     "But perhaps it is we who fear the perplexity and disorder that for them is already intrinsic to life. For my part, I do not believe them to be in any worse straits than my generation. Like us, they long to experience life in all its fullness and measure. They are anxious to engage us in conversation that is real, undiminished, Dynamic. Weary of little packets, they want the load." [Donald W. Thomas (1987), "The Torpedo's Touch", Teachers, Teaching & Teacher Education, edited by Margo Okazawa-Rey, James Anderson, and Rob Traver, Harvard Educational Review Reprint Series, No. 19, p.14.]

Q1. What do butterflies do when they are in their cocoons? How do they become butterflies?

A1. Let's start at the beginning of a butterfly's life. Mother butterflies (and mother moths) lay eggs which have caterpillars inside them. They lay these eggs on the leaves of plants that their children, the caterpillars, will like to eat. Scientists call the caterpillars "larvae"; they use this word to describe baby animals that are very different from what they will be like as an adult. The caterpillars eat their way out of their eggs and immediately begin eating the leaves of the plant they are born on. Caterpillars eat, and eat, and eat.
The caterpillar keeps growing bigger and bigger, and has to shed its old skin and grow a new skin several times so that it has room to grow. Eventually, the caterpillar will stop eating and attach itself to a plant. The caterpillar then makes a case around itself (a chrysalis). Butterfly caterpillars don't actually spin cocoons, like moth caterpillars do. When you look at the outside of a chrysalis, it doesn't look like anything is happening until right before the butterfly is ready to come out, but the larvae is really very busy.

While in the chrysalis, most of the caterpillar's body dies and the new butterfly body grows from it. The butterfly-to-be grows a new digestive system because it will eat the liquid in flowers instead of solid leaves like caterpillars do. Wings grow from disks that were already inside the caterpillar, and its muscle system changes so that it can control the new wings and fly. The larvae's way of sensing the world also changes. Caterpillars learn about the world by what they feel, while butterflies rely more on sight and smell. Caterpillars have eyes which can tell light from dark, but their eyes can't see colors and aren't very useful. Butterflies have eyes that see colors and they find the flowers they get food from with their eyes. Does anyone know any other ways that butterflies are different from caterpillars? (Possible responses include: caterpillars have a lot more legs than butterflies, butterflies wings are brightly colored, butterflies are "prettier.".,

Related information:

1. Cocoons are a special kind of chrysalis made by moth caterpillars. They are spun from a silk-like fiber and are often soft and fuzzy while a butterfly's chrysalis is usually smooth and firm. The silk fabric used in clothes is made from silk fiber unwound from the cocoons of silk caterpillars ("silk worms").

2. The larvae goes into its chrysalis stage when it's brain slows down the production of a chemical, called its "juvenile hormone". The larvae will stay a caterpillar as long as there are still large amounts of this hormone present, growing larger and larger but never forming a chrysalis or transforming into a butterfly regardless of how much it eats, and regardless of its age.
 
 

     Five second-graders at Bottenfield school had wired up lights in a house they had made of a cardboard box. When the teacher asked them what they had learned, one boy said something surprising: "Sometimes you don't have to use batteries to light up stuff." That made me think that batteries and bulbs, like most school science activities raise more questions in some children's minds than they answer.
Here is a sample of questions and answers--our computer dialogue with undergraduates doing batteries and bulbs in an elementary science methods course:

Ql: What's in a battery that makes electricity?
A1: Any two different metals placed in salt water or a weak acid (like lemon juice or vinegar) generate electricity. The voltage depends on which metals are used. E.g.. A strip of zinc and a strip of copper placed in, knife stabs in a lemon may generate a volt or two--just barely enough to feel it if you touched them to your tongue. A regular flashlight battery (the kind that should not be recharged) works similarly, enclosing a pole of manganese dioxide in a solution of ammonium chloride and zinc chloride in a zinc case. Alkaline solutions are sometimes used instead of acids. In these batteries, zinc is usually one metal and carbon takes the place of the other.
Rechargeable batteries used in cars may have one set of lead plates and another set of lead oxide plates inside a solution of sulfuric acid. As the battery is used, the lead plates react with the sulfuric acid and change to lead sulfate, and water is released into the sulfuric acid solution, making it more dilute. If the cars generator works properly, running the car recharges the battery by reversing this chemical reaction.

Q2: Where do we get the electricity for lights in our homes? I know there is a power plant, but how does it all work?
A2: There are many ways of generating electricity. These include rubbing surfaces together (shoes on carpet, synthetic fabrics in the dryer, etc.), the chemical reactions of metals and electrolytes (zinc, copper, zinc--carbon batteries, or mercury or lead rechargeable batteries), solar cells (a type of chemical reaction activated by light), and the electromagnetic method which is usually used by power companies to generate electricity for use in homes and businesses. This method was discovered by Joseph Henry and Michael Faraday. They found that electricity could be generated by moving one magnet near another (many coils of wire, or electromagnets, are often used). The generators used on bicycles, windmills, or in huge power plants use this principle. A motor or generator is a device for converting electrical energy into motion energy, or vice-versa. This process is described in diagram 1.

Related information:
Voltages above 50-60 volts can be dangerous to human life, but most appliances in our homes use 120 volts, so be careful not to touch their wires. Flash lights, portable radios, toys, smoke detectors, etc. work on batteries that have from 1.5 to 9 volts, so they are very safe --unless you hook enough batteries together to raise the voltage above 50 volts.  Flash lights, portable radios, toys, smoke detectors, etc.

work on batteries that have from 1.5 to 9 volts, so they are very safe --unless you hook enough batteries together to raise the voltage above 50 volts.  In order to send electrical energy over long wires from a huge power plant to your home, engineers (especially Charles Steinmetz) discovered that they had to use very high voltages, or they lost too much electrical energy in the wires.  A transformer is a stationary device like an electromagnet with two coils instead of one that can step up or step down the voltage. A transformer for stepping up the voltage has a coil of wire (electromagnet) that sends a moving magnetic field through another coil with many thousands of coils. A step down transformer to make the voltage smaller for greater safety in our homes, or really safe for electric trains, battery chargers, etc. works the opposite way. A large coil sends a magnetic field into a smaller coil, thus "inducing" a smaller voltage. (See diagram 2)

The students continued this dialogue with the following
questions:

Q3: Is a light bulb like a tiny transformer?
Q4: What creates a 40 and 60 watt bulb?
Q5: What is the filament made of?  

     In either case, it "freezes" motionless if it hears a threatening sound and is easily mistaken for the part of the plant it resembles. Laboratory experiments suggest that the flowers must be better food than leaves, because caterpillars fed only oak flowers become fatter and pupate earlier than the ones fed on leaves and when they turn into a moth, the females of the catkin-fed moths lay more eggs. 

     I ask the observers, "Do you see where the sunlight is hitting the ball? Does that part of the ball that is lit by the sun look like the part of the moon that is lit up?" All look and are surprised to see that it looks exactly the same shape. "Ok, you come here and hold the ball," I say to one boy "so I can stand over there and see it myself." I was impressed, too, at how precisely the same crescent shape in the same position was showing on both the moon and the tennis ball.

      Thursday, February 2, 1989, my wife, Elizabeth, and I are driving east to the university at 7:00 am, and straight ahead of us is a "sun dog". We can occasionally see the rising sun off to the right through trees and houses, but nothing obscures the bright rainbow-colored vertical streak in the sky in front of us. We can't see to the right of the sun, where there ought to be a similar sun dog. By the time I drop Elizabeth off at the university and drive to Bottenfield school, the sun has risen higher and the sun dogs, which are caused by ice crystals falling through still air, have disappeared.

     Tuesday, February 7, 1989, Elizabeth and I were driving west along Green Street. at about 7:00 pm, when she asked if l had seen the moon. I hadn't, but I remarked that the crescent shape should be on the bottom. "That's right," she said, how did you know?" "Because the sun has already set and is shining up on it from below," I said. Soon, I saw it too, ahead between some houses along the south side of the street. It seemed only yesterday, I had seen it above Bottenfield School in the morning with its East side lit up.--JE