Coyote Science

"Astrophysics" CS#22

2008-11-27T07:38:00.000-08:00

Coyote Science Activity 22

Astrophysics (image not available yet)
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New Moon, Full Moon?(If it's the same Moon why do we call it "new"? And what's it full of anyway?)
By Bob Culbertson 1993, 2005 ©

Materials:
String
Old tennis balls
Wire coat-hangers

Tools:
Scissors
Knife
Gloves
Table lamp without shade

To demonstrate relative sizes and distances, a student's head and an old tennis ball can represent the Earth and Moon. A string wrapped around the head (Earth) one time will wrap around the ball (Moon) 3 times. Another long piece of string wrapped around the head 12 times will stretch out to represent the distance between the Earth and Moon.

The relationship between sun, Earth and Moon is not always understood and sometimes people think that the phases of the Moon are caused by the Earth's shadow. A simple lunar model can be made with a wire coat hanger and a tennis ball. Grab the hanger's hook and the other side of the coat-hanger and pull apart until there is a diamond shaped space big enough to put your head in. Push the tip of the hook through a 1/2" slit cut in the tennis ball (wear gloves when cutting the slit) until it's completely inside the ball. Put the coat-hanger over your head and keep the tennis ball in front of your eyes. Now your head is the Earth, the tennis ball is the Moon and a table lamp without a shade is the sun. As you turn around you can see the different phases of the Moon (just the Day and Night on the Moon, like on Earth) and eclipses of both the Moon and sun (which depends upon whether the Earth's shadow falls on the Moon or the Moon's shadow blocks sunlight from hitting the Earth).

Eclipses are very rare but with a tennis ball and coat hanger you can make them anytime you like.

References:

"The Book of the Moon" by Thomas A. Hockey, 1986, Prentice-Hall Press, Gulf+Western Building, One Gulf+Western Plaza, New York, NY 1002

"Conceptual Physics", Paul Hewitt, Little, Brown and Company ISBN 0-316-35974-2

"Geophysics" CS#21

2005-05-01T19:23:00.000-07:00

Coyote Science Activity 21

Geophysics
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Geophysics (Where "plates" don't hold potato salad.)
By Bob Culbertson 2005 ©

Not too long ago people thought the surface of the earth couldn't change, but some scientists were puzzled by places separated by thousands of kilometers that seemed as if they had been together at one time. Fossils and mountain ranges ending at the east coast of South America matched those beginning on the West coast of Africa, but with a wide Atlantic Ocean between them.

We now know that the earth is covered by huge systems of rock called "plates" that slowly move and interact with each other. "Oceanic plates" are mainly found beneath oceans and most of us live on the dry land of "continental plates." The way in which these plates interact depend upon the difference in their density and how they meet.

The cause of their movement was first found beneath the Atlantic Ocean where molten rock from deep within the earth comes up through the ocean floor and pushes the older sea floor aside. This is called a "divergent boundary" and creates new rock that is commonly found on the bottom of the oceans but can also be found on land. The Great Rift Valley in East Africa and the Gulf of California are examples that can easily be seen on a map.

Since the divergent boundary's new rock needs room and the Earth can't get any bigger, something’s got to happen to the old rock. A "convergent boundary" is where the old rock is being changed and here’s 4 ways it happens:

1. When oceanic and continental plates meet the oceanic plate will slip under the less dense continental plate and melt deep in the earth's crust; a great source of material for volcanoes.

2. Two oceanic plates will bend downward when they meet and form deep underwater trenches, many of which are found in the western Pacific Ocean.

3. And where two continental plates meet they'll bend upward to make huge mountains like the Himalayas between India and China.

4. In some places the plates slip by each other at a "transform boundary." The North American (continental plate) and Pacific (oceanic plate) plates grind by each other along the San Andreas fault that runs from Mexico into the ocean near San Francisco.

Many earthquakes are the result of the interactions of these plates. Energy from their movement against each other is released all of the time. Sometimes this energy is released in amounts large enough for us to feel and even cause damage.

Picnic Table Top Tectonics

You'll need 3 paper plates (the easily bent kind work best), a brown, green and blue crayon and a world map, or globe. First, draw lots of green lines across one of the plates then tear the plate in half and put the 2 pieces back together. See how the lines match? Slowly move the pieces apart but no matter how far you move them they'll still match when brought together again. You can easily move these pieces apart with your fingers, but molten rock is needed to move the earth. Find Africa and South America on your map, or globe, and you'll see that even though they've been moving apart for millions of years they still would fit back together pretty well.

Next, color the inside of the two other plates with a brown crayon to make "continental plates." Slide these plates together on the table until their rims meet and are pushed up into the air. You've just made mountains. Find China and India on your map, or globe, and the tallest mountains in the world (the Himalayas) between them. They were formed when two continental plates pushed, and continue to push, into each other.

Now, turn your paper plates upside-down and color the bottoms with the blue crayon to make "oceanic plates." When you slide them together their rims push each other until they dip down. Under the ocean this would be called a "deep-ocean trench." Look on your map or globe for the Mariana Trench, between Japan and Australia, and its Challenger Deep, at 11,000 meters, is the deepest place in the world.

This time, slide a continental plate (brown side up) into an oceanic plate (blue side up) and see what happens. The oceanic plate slips under the continental plate and dives deep into the earth where it melts. Some of it can come back up in a very dangerous type of volcano which can explode when the water trapped in its rocks turns into steam too fast. Coastal Oregon, Japan and the west coast of South America are a few of many places where an oceanic plate is slipping under continental plates and creates lots of volcanoes. (Just think: As the Atlantic Ocean gets larger the Pacific Ocean becomes smaller until millions of years from now Asia and North America will become one big continent again!)

Place the palms of your hands together and gently rub them back and forth, like you're making a clay snake then press your hands together tightly and try the same thing. Your hands will stick together then suddenly slip, just like a "transform boundary" between plates. Our San Andreas fault is famous for storing energy when it "sticks" then releasing it when it "slips" causing large earthquakes.

References:

"Essentials of Geology", Frederick K. Lutgens & Edward J. Tarbuck, Merrill Publishing Company, ISBN 0-675-20749-5

"Antlion" CS#20

2005-04-10T07:55:00.000-07:00

Coyote Science Activity 20

Antlion1
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What Isn't an Ant, or a Lion? An ANTLION, of Course!
By Bob Culbertson 2005 ©

What qualities would the perfect pet have? Fun to watch, quiet, cheap to feed, helps control pests, doesn't bite or need baths, doesn't need a sitter during vacations or poop, and after 2 or 3 years turns into a beautiful creature that needs to be set free. Impossible (one might think) but it does exist; it's called an "antlion".

An insect goes through several changes, usually egg to larvae to adult, and most of us are familiar with a caterpillar (larvae) changing into a butterfly (adult). The antlion larvae in our area looks something like a 1 cm turnip with jaws; it only moves backwards and never sees where it's going but is still able to dig a sand-pit in which it waits for some creature, usually an ant, to fall in. The larval stage lasts several years and is entirely devoted to eating and since it only eats the juice of the creatures it catches it doesn't even need to poop (Can't! Doesn't have an anus!). It finally turns into an adult that looks something like a dragonfly with large eyes and beautiful lacy wings. If you're lucky you'll see one visiting patio lights some late spring or summer evening.

It's easy to care for an antlion pet but first you have to find one. Look around the edges of houses where the dirt is protected from the rain where their cone shaped pits are easy to spot. Use a straw to carefully blow away the sand to expose the antlion then use a leaf or plastic fork (be careful not to squash it) and scoop it into a cup. Pour sand (from the same place) through a screen into an empty plastic jar until it's half full. Set the jar in a shallow pan of water (to keep ants, the lion's dinner, from escaping) drop in the antlion and you're all set. Catch the small Argentine ants that invade kitchens with a "pooter" (see the first reference) made from a small jar, tubing and cotton filter and feet the antlion daily. Don't worry about leaving it a couple of days, it doesn't need water and can go for a long time without food.

The antlion larvae will eventually stop eating and won't make a pit anymore but will spin a cocoon of silk a little smaller than a marble that's soft on the inside but covered with dust and sand particles on the outside. Inside this cocoon the larvae changes into the adult "imago" stage and will cut its way out, ready to fly away to mate and make more antlions.

The antlion makes a pit in sand by moving in a spiral while flipping out grains of sand with its huge jaws. The type of sand is very important; if it's too coarse the grains won't stick together enough to make a deep pit, wet grains will stick together too well and the ant will get out. They seem to prefer an area with a layer of loose sand covering compacted sand (to make burrows in) protected from rain and dew.

Insects that live in sand must have hairs on their bodies to keep sharp particles away from the wax-like coating on their bodies. An ant's hair points backward from the head and can only go forward in the sand, ant lion hair points forward so they can only back up. When they grab an ant they can pull it deep into its burrow and the ant can't back up to escape! Dry foxtail, or hare barley, seed heads usually end up in your socks but the green ones show the importance of an insect's hair direction. Lay your hand flat on the table with the palm up and the fingers together. Place the foxtail seed head in the trough between two fingers with the stem towards the fingertips and put your other hand over the first. Now slide your hands up and down and the foxtail will crawl out. The hairs on the foxtail allow it to be pushed by your hands in one direction but not the other. This is a lot like the hairs on an ant, or ant lion, the direction of the hairs prevent the ant from backing up and the ant lion from going forward.

References:

"How Nature Works", David Burnie, 1991, Dorling Kindersley Limited, London, ISBN 0-89577-391-0

"Grzimek's Animal Life Encyclopedian, Volume 2 Insects", Bernhard Grzimek, 1975, Von Nostrand Reinhold Company, New York, Library of Congress 79-183178

"Insects of the Los Angeles Basin", Charles l. Hogue, 1993, Natural History Museum of Los Angeles County, Library of Congress 93-084264

"Bleach maker" CS#19

2005-04-09T11:54:00.000-07:00

Coyote Science Activity 19

Bleachmaker
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Cheap Electrochemistry
By Bob Culbertson 2005 ©

Caution: A small amount of flammable gas is released during this experiment. Do it in a well ventilated area away from any fire or flame. If wax is used as a sealant melt it in a can in hot water, not directly over an open flame.

Using saltwater as a conductor of DC electricity causes the water and salt to separate (called "electrolysis") into a number of interesting compounds. At the negative side (cathode) hydrogen and sodium hydroxide are produced and chlorine gas forms at the positive side (anode). Sodium hypochlorite (NaOCl), or bleach, is formed by the reaction between sodium hydroxide and chlorine when the cathode and anode are separated. A small amount of bleach can be made for a few cents worth of common materials and a source of DC electricity.

The anode and cathode "electrodes" are made from pencil leads because the graphite and clay that they are made from doesn't contribute chemicals to the bleach. Stainless steel and many other metals should not be used. The pencil leads will eventually be destroyed by the chemicals they help make but usually takes a while to happen.

Seawater can be substituted for salt and water but filter it through a paper coffee filter or fine weave cloth first.

Materials:

2 Styrofoam plastic cups
1 cup water (about 200mL) or clear seawater
1 teaspoon plain salt (about 5 grams)
2 pencil leads about 7cm long (cut out of wooden pencils)
1 tube of waterproof glue or a metal can of melted wax (some glues can melt the Styrofoam cups!)
1 stiff piece of metal wire about 18cm (6inches) long (like part of a wire coathanger)

Misc:

Filters for seawater and the final product, several pieces of coffee filter paper or tightly woven cloth

Tools:

Some sort of DC electrical power source such as 2 flashlight batteries or solar cells (3volts at less than 1/2 watt)
2 30cm (12 inch) electrical wires with clips on both ends
1 small spoon
1 iron nail and a piece of sand paper to make a bleach "Tester"

How to do it:

Push the stiff metal wire through both sides of one of the cups about 1 cm (1/2 inch) above the bottom then push one of pencil leads through those same holes so that the ends stick out of the cup. Make another set of holes about 2cm (5/8 inch) above the first set and put a pencil lead through them too. Seal the holes in the cup with glue or by dipping it in melted wax. Repeat as many times as necessary but don't get wax inside the cup. Carefully scrape away the wax from the ends of the pencil leads.

Mix the salt and water together (or filtered seawater) and pour into the cup with the pencil leads. Connect the positive terminal of the DC power source to the bottom pencil lead and the negative terminal to the top one with the electrical wires with clips on the end. Bubbles will start forming and there may be the faint odor of chlorine. Bleach is now being made.

Using 3 VDC takes a long time to make bleach, perhaps 24 hours, so it should be tested to see when it is ready. Take the bleach "Tester" (iron nail and sandpaper) and rub the nail with the sandpaper until about 2cm of it is shiny. Put the nail into a cup and cover it with some of your bleach. If the bleach is ready the nail should become very rusty in a just a few minutes; if not then the bleach making process must continue some more.

To use the bleach:

Filter it, then mix with 2 liters of clean water. Wash some fruit with it and compare the washed fruit with unwashed and see which becomes moldy first.

References:

Chemistry, by Glenn H. Miller, 1969, Harper & Row, Publishers, New York, Evanston and London, Library of Congress Catalog Card Number: 69-10550

Clorox Company at www.clorox.com

"How seeds get around" CS#18

2005-04-03T14:59:00.000-07:00

Coyote Science Activity 18

Seeds
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Fliers, Floaters, Fallers, Eaters & Travelers
(How seeds get around.)
By Bob Culbertson 2005 ©

The "3F,E & T" are the basis of demonstrations and discussions of the most common types of seed dissemination using examples from vacant lots, gardens and supermarkets. Identification is simple, easy to remember and can be applied to an urban environment.

Fliers:
Seeds that are transported through the air either by passive or active means. Passive types (dandelions, artichokes, willow, etc.) depend upon the action of the wind to carry them. The active types (California poppy, impatiens, yellow oxalis, etc.) propel their seeds through the air to land in a suitable environment or stick to an animal for further transport.

Floaters:
These rely upon water to carry them to a new environment. Most are found in, or close to, fresh or sea water (water lily, sycamore, surfgrass, etc.) and one of the best examples is the fruit of the coconut palm. The coconut's thick waterproof husk allows it to float in the ocean until washed up on a beach.

Fallers:
Many of our most common plants only require gravity to aid their dispersion. They are usually smooth and heavy without a thick protective husk (nuts, beans, castor beans, and grass seeds like wheat and oats). Their smooth surface allows them to slip through a thick covering of leaves to get to the ground. Oats will also twist themselves into the ground with their long tails.

Eaters:
A source of food for many animals (including humans) is the fleshy covering surrounding many types of seeds (apples, toyon, oranges, watermelons, etc.) Animals that like to eat the fruit are not likely to damage the seeds which pass through their digestive system and are dropped on the ground in a protective covering of feces, all ready to sprout.

Travelers:
A short walk through a vacant lot in late spring or summer will collect dozens of these seeds in your socks. Most of them (cockleburs, foxtail fescue, mistletoe) will hitch a ride on any passing animal with sharp barbs or a sticky coating. However, the Russian thistle (tumble weed) plant is blown loose by the wind and can tumble for miles, spreading its seeds all the while.

Some seeds combine 2 or more of these methods. Filaree will stick to your socks (travelers) and drill itself into the ground (fallers) after you pull it off and throw it away (the seed not the sock).

References:

"Introducing Biology" Third Edition by Bonita L. Roohk & Arnold J. Karpoff, Kendall Hunt Publishing Co. 2460 Kerper Blvd., PO Box 539 Dubuque, Iowa 52004-0539

"Natural History of Vacant Lots" by Matthew F. Vessel & Herbert H. Wong, University of California Press, Berkley, California

"Inertial guide" CS#17

2005-04-03T07:30:00.000-07:00

Coyote Science Activity 17

Inertial guider
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Inertial Guide
By Bob Culbertson 2005 ©

Knowing where we are has always been difficult and getting lost can be inconvenient or disastrous. As distances traveled and the speed of our vehicles increased, the need for better ways of direction finding also increased. Magnetic compasses (a tremendous advance in navigational science in the days of slow sailing ships) were almost useless when piloting an aircraft through 3 dimensional airspace. Fortunately, basic concepts in physics were carefully engineered into practical instruments that would finally meet those needs.

This demonstration shows how "inertia" can be used to tell us where we're at and how to get to where we want to go. An object (any kind of matter) hates to change what its doing: if moving it wants to continue to move; if resting then, "Dog-gone-it!" it's going to remain at rest. Unless some energy is added (kicking a soccer ball) or taken away (same ball rolling through wet grass) an object (Mr. Soccer Ball) will continue doing whatever it was when you found it.

Note: From personal observations you know that we are surrounded by energy hungry things and a soccer ball will lose the energy acquired when booted to those things (grass, mud, goalie's heads, etc.). It will not go rolling on forever, in fact it will only roll far enough to get stuck in dark places that smell bad or onto a street where it will be run over by a truck.

How to apply this knowledge of inertia: If we point an arrow in the direction that we want to travel and isolate it from things that might add or take its energy away then it will always stay pointed in that direction. Simple concept but not easy to do. Navigational instruments that use this principle are very accurate but also complicated, delicate and expensive. We'll make an "Inertial Guide" that isn't very good but is simple, rugged and cheap. It consists of an indicator (arrow on foam disk), energy isolator (water) and housing (plastic bowl). Since water doesn't stick very well to plastic it doesn't receive or give up much energy to the plastic and remains in the same position (more or less) as you move the bowl around; the arrow shows how much it hasn't moved

It's easier to understand after you've tried the demonstration (that's what it's for anyway).

Materials:

1 7.5x7.5 cm (3x3 inch) square piece of 2 cm (3/4 inch) Styrofoam sheet

7 Toothpicks

1 10 cm (4 inch) diameter, straight sided, plastic bowl

Water

Tools:

Compass for drawing circles, knife, black marker

How to do it:

Use the compass to draw a 7.5 cm (3 inch) diameter circle on the Styrofoam then cut it out with the knife (be careful!). Poke 6 of the toothpicks into the edge of the foam disk so that they look like spokes in a bicycle wheel; press each of them in until only 5mm (1/4 inch) is above the foam. Draw a big arrow on the top of disk and put the last toothpick in the center to use as a handle.

Fill the plastic bowl about 1/2 full with water and set the foam disk on top of it. Hold the bowl steady until the disk is quiet then rotate your entire body while watching the position of the arrow. The arrow will always try to point in the same direction.

Try different speeds and directions, as well as, different size and shaped bowls, liquids too. What works best?

"Boiling Point vs Altitude" CS#16

2005-03-19T05:30:00.000-08:00

Coyote Science Activity 16

Boilingpoint1
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Steamed Up About Altitude!
(or "How to Turn Tepid Tea Into a Science Experiment")

By Bob Culbertson 2005 ©

The higher above sea level ("level" hardly seems right considering the effects of gravity, ocean waves, gyres and tides) the lower the air pressure which lowers the boiling temperature of water. This change in temperature can be measured with a thermometer to quickly determine the altitude of any place on earth. Although not as accurate as more time consuming or expensive methods it can be done by anyone with very simple equipment.

Be aware that measurements are affected by the weather and type of water used. During stormy weather the air pressure (called "barometric pressure") drops slightly and rises when clear; and very dirty water, or water with lots of minerals in it, can also change its boiling temperature but neither makes too much difference. If you use clean drinking water on a sunny day your measurements will be fine.

Fire and boiling water are dangerous! Always be safe and have responsible adults helping. Open fires are not recommended and always have a bucket of cold water handy to put out fires and dunk burned fingers into.

Materials:

500 ml clear drinking water

Some way to boil water

Misc.:

Mug, tea, cocoa or coffee, sugar, spoon, biscuits

Tools:

Thermometer with a 2 degree or better scale in either F or C

Small metal teapot, can or cup with handle

Camping stove or other portable heat source

Elevation v/s boiling conversion calculator (see "References:")

Map with altitudes

Small notebook

Pencil

How to do it:

Fill the pot, cup or metal can about 2/3 full of water and bring to a rolling boil . Place the thermometer into the boiling water being careful not to heat the top of it in the flame outside the pot. Gently tap its dial, or upper stem, with a pencil and record the temperature in the notebook; also include your location, date and type of weather. Use the References section's "Boiling point conversion calculator" to find the boiling point closest to yours and write down the elevation associated with it. Now make a hot drink and relax.

Later, compare your measured altitude with the same location on a map. Try to repeat the boiling point measurement during different weather to see how changes in barometric pressure affect it. Checking your measurements against known altitudes will help determine how close you would expect to be at an unknown location.

References:

Boiling point conversion calculator (with permission) at " http://www.csgnetwork.com/h2oboilcalc.html "
"Trespassers on the Roof of the World: The Race for Lhasa" by Peter Hopkirk, Oxford University Press, 1983
"Pocket Ref " 1995, by Thomas J. Glover, Sequoia Publishing, Littleton, Colorado

"Colors to Dye For" CS#15

2005-02-28T04:36:00.000-08:00

Coyote Science Activity 15

Drinkable dyes
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Colors to Dye For!
By Bob Culbertson 2005 ©

Very few mammals see colors but humans not only just see color, they celebrate that vision by draping their (rather drab) bodies, tools, clothes, homes and other animals with every color of the rainbow. After using all the natural sources of color (animal, vegetable and mineral) they have gone on to make their own that rival nature's in variety, brilliance and permanence.

This activity allows us to safely explore a world of color by using instant beverage mixes to color, or "dye", cotton cloth and string. Water is used to dissolve the mixes and vinegar is added to clean the fabric's surface and let the dye attach more easily. The resulting colors are pleasant smelling soft pastels that fade with use and washing. Wash separately!

Materials:

Grape, cherry, lemon/lime etc. instant beverage mixes (similar to Kool-Aid ©) and instant coffee

500 ml vinegar

1 liter water for each color used

Various pieces of 100% cotton cloth in 1 ft. (30cm) squares and/or cotton string

Old newspapers

Tools:

500 ml water

Tools:

Old jars (glass or plastic) with lids, one for each color

1 Measuring cup

Many spoons

Rubber-bands (for tie-dyeing cloth)

1 pair of scissors

How to do it:

Wear old clothes and cover the table with newspapers to protect from spills.

Pour the packages of mix in separate jars and add 1 cup (250mL) tap water and ¼ cup (70mL) vinegar, stir well. For a brown color use 2 teaspoons of instant coffee instead of beverage mix.

Prepare the cloth with rubber bands for tie-dyeing (check hobby books or ask an old "Hippie" from the '60's) and cut the string in easy to use lengths. Put the fabrics in the jars and press them under the surface until you get most of the bubbles out (otherwise they float). Cover with the lids and let sit, in a warm place if possible, for at least 2 hours; the colors will be darker if left longer.

Remove the fabrics and rinse in cool water then let dry. Ironing will remove the wrinkles from the cloth but pressing between newspapers with heavy weights works too.

Things to try:

Use cloth that is already colored before tie-dyeing to get different effects. Dye string a light color first then tie knots in it before dyeing it a darker color, untying the knots will reveal a string with 2 colors. Does heating the dye in the sun make the fabric colors darker?

References:

"A Practical Guide to Edible and Useful Plants" by Delena Tull, Texas Monthly Press, Inc., PO Box 1569 Austin, Texas

"Egg-perimental Membrane" CS#14

2005-02-26T09:28:00.000-08:00

Coyote Science Activity 14

Egg membrane
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Egg-perimental Membrane
By Bob Culbertson 2005 ©

Materials (to make 2 membranes approximately 2.54 cm in diameter):

1 large raw egg

100 ml vinegar

500 ml water

Materials (for testing)

5 grams salt

4 drops food coloring

5 grams starch

5 drops iodine

500 ml water

Tools:

1 push-pin or other sharp pointed object such as a nail or screw

1 plastic cup

1 frying pan

1 pair scissors

1 small glass jar with lid, or plastic wrap

2 film cases

2 rubber bands

Carefully chip a hole in each end of the egg with the push-pin or nail and blow in one of the holes to force the yolk and white out the other into a cup (make a scrambled egg with the cup's contents). Now clean the inside of the egg shell by sucking fresh water into the egg shell, shake around a bit, and blow it out. You now have a clean empty egg that consists of a hard calcium outside layer and a white membrane inside of it.

Put the empty egg shell into a jar and fill with about 100 ml of vinegar and cover with a lid, or plastic wrap. Depending on the strength of the vinegar and how much the container is shaken, the hard calcium will dissolve in about 2 days. Remove the thin tough membrane from the vinegar and wash it with fresh water. Blowing gently into one of the end holes will inflate the membrane. An egg balloon!

With a pair of scissors, cut the membrane in half from end to end. You now have 2 halves of a membrane that is seldom seen. It allows the transfer of carbon dioxide, oxygen and water vapor while preventing the loss of liquid, and blocks the passage of bacteria.

Put salt in one of the film cases and fill with water then cover with one of the membrane halves and secure with a rubber band. Put into a clear jar of water with the membrane side down. Look through the jar at a bright light and see the diffraction of light caused by the salt ions leaking through the membrane into the fresh water.

Put starch in the other film case, fill with water and cover with the other membrane half. Secure with a rubber band and place in a clear jar of water with the membrane side down. Leave overnight then remove the film case and put several drops of iodine in the jar. If it turns black then starch leaked through the membrane, but if the iodine remains red then that indicates the starch molecules were too large to get out.

References:

"Birds" Barry Wilson, W. H. Freeman and Company, San Francisco, ISBN 0-7167-1206-7

"Kinetic Kastles" CS#13

2005-02-23T15:00:00.000-08:00

Coyote Science Activity 13

Kinetic Kastles
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Kinetic Kastles
By Bob Culbertson 2005 ©

Making a sand castle at the beach is great fun but when finished it just sits there until either the tide comes in or someone jumps on it. Next time build a "Kinetic Kastle" and drive the lifeguards nuts. Here's what you do.

Materials:

1 sandy beach, the bigger the better

6 people (one works, five watch)

Lots of old tennis/golf/basket/bowling balls

Tools:

Shovels, rakes, hoes, trowels, buckets, beverages, sun block, folding chairs, sunglasses

Directions:

Make a big pile of wet sand, the taller the better, and carve roller coaster ramps in it for the balls. Make tunnels and drops and water hazards (water filled bucket) and see how far (and how crazy) the balls will go. As an alternative, build a long ramp starting at the highest point on the beach a see how far long you can keep it going.

Here's some things to think about while you're making a "Kinetic Kastle": The higher the starting point is (greater potential energy) the further the ball will roll but also try making the ramps as smooth as possible to reduce energy lost to friction (changes to heat rather than motion). The trick for a roller coaster, and a Kinetic Kastle is to keep rolling. Energy is always lost so the starting point is always the tallest and everything afterwards is lower. When you no longer have enough energy you stop. so try to keep it going as long as possible.

Believe it or not, an early scientist named Gallieo did the same thing when he was studying falling objects but all he had was wooden ramps and iron cannon balls. Just think what he could have done for science if beaches had been invented!

References:

"Conceptual Physics", Paul Hewitt, Little, Brown and Company ISBN 0-316-35974-2

"Sounds Easy" CS#12

2005-02-23T07:27:00.000-08:00

Coyote Science Activity 12

Sound makers
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Sounds Easy!
By Bob Culbertson 2005 ©

This activity can be broken into smaller units for easier presentation.

Sound is a very useful way to find out about the world. It doesn't require much energy, can be used when you can't see or smell things very well and isn't messy. Tonight we'll have some fun exploring ways animals use sound and try to understand some of its uses, advantages and disadvantages.

Materials:

Rasps (plastic knives with serrated edges 2 per visitor, instructor and assistant)

Whistle (1 for instructor)

Hands and ears (2 per visitor)

Yellow barrier tape (about 50 feet)

Flashlight (1 per instructor and assistant)

Communication Have assistants communicate to one another using the code:

One sound is "Hello."

Two sounds is "I'm here."

Three sounds is "Help."

Have 3 assistants stand in different locations then individually signal them to use their rasps. Have the audience locate them with their ears, then show how much better it can be located when hands are cupped behind the ears (extended ears). Cover one ear and try it again. Does one ear work better? Worse?

Things to ponder:

How do big ears, or special shapes, help predators locate their prey? Why do we have 2 ears? Why have ears on the side of your head and not one in the middle?

Predator v/s Prey

Preparation:

Have assistants, or select "volunteers" from the audience, to distribute 1 pair of rasps to each participant. Explain how grasshoppers make sound by rubbing rough places on their back legs against tough parts of their forewings (stridulating). This is very similar to drawing the back of a plastic knife along the serrated edge of another one. Have everyone make a lot of noise with them and then blow whistle. Explain that the whistle means "STOP THE NOISE" so that we can continue.

Divide the participants in half with yellow barrier tape to allow "predator" and "prey" group activities. Begin by designating one group as prey and the other as predators. Select a single prey to make noise and ask the predators to locate it with their ears. Then have all of the prey make noise at the same time to confuse the predators. Can the predators locate the single prey now? Switch roles and repeat.

Things to ponder:

How are predators confused by multiple sounds? How can the prey communicate with all of the noise?

To Do At Home:

Close your eyes and use sound and your ears to learn about the size and type of room you are in. This is how bats learn about their environment, are there others?

"It's About Time" CS#11

2005-02-23T06:34:00.000-08:00

Coyote Science Activity 11

Compass at Nature Center
Posted by Hello

It's About Time
(September 22, 2000 Fall Equinox)

By Bob Culbertson 2005 ©

For much of time past the world was a very lonely place for the few humans living on it. The huge numbers of people now on Earth and the ease in which they travel and communicate was inconceivable to our ancestors whose social unit was family size, the only transportation was by foot and communication by word of mouth. Families, clans and tribes broken apart by nature, the need for food and shelter and the desire to live in someplace new were remembered in the elder's firelight stories by which the longing to be reunited, if only for a few days, was kept alive. Surely there must be a way for a widespread people to gather together to celebrate, to remember, to love but how could they meet when travel time was measured in weeks and simple greetings could take dangerous months to deliver? How to do it?

The solution must rank among the earliest and greatest inventions ever made and was perhaps the first time creation of new knowledge (science) was applied (engineered) to make a new way of doing things (technology). It was discovered that the Sun's position in the sky changed from season to season in a predictable way, that those changes could be measured and were the same anyplace in that very small world. The times of greatest change were at the extremes of the Sun's position, called "solstices" (Sun + stand still) and happened in summer when daylight was long and winter with its long dark nights. The other two important times were midway between the solstices and called "equinoxes" (equal + night) whose (assuming no mountains in the way) sunrises would be due East and sunsets due West.

With this knowledge instruments were made to accurately measure the changes and, since that was a very long time ago, the first ones used natural features such as cracks in rocks, mountain peaks and trees; the shadows made by them recorded with pebbles on the ground or scratches on stone, wood or earth. Later these instruments would be called "Sunwheels" and could be as simple as a few stacked stones on the plains of Montana or as grand as huge slabs of rock carefully transported, cut and placed such as those at Stonehenge, England. Regardless of their size and complexity their purpose was to indicate a universal measure of the year, what would now be called a calendar.

Applying this amazing new technology would go something like this:

A season is decided upon for a gathering of families/clans/tribes; winter is too cold (snow!), summer is too busy (food gathering) and hot so spring and autumn remain. Since it rains a lot in spring (remember traveling is by foot) and there still isn't much food available yet (no grocery stores for another 25,000 years) autumn is best. Since it takes about 10 days for the furthest family to travel to the meeting site the date for the gathering is planned for the twelfth day after the fall equinox.

The family/clan/tribe's shaman consults the local Sunwheel and keeps track of the Sun's position, she notifies the leaders when the equinox draws near. Food and supplies for the trip are collected and excitement mounts until the departure date arrives bringing the sadness of separation from those unable to travel but the expectation of a joyful welcome by dimly remembered loved ones from a year ago.

I celebrate the equinox by going to my favorite East/West pointing street (Sunflower between Susan and Harbor between Costa Mesa and Santa Ana) at sunset Since there are no mountains in the way the Sun sets directly in the West which makes all the shadows of the streetlight poles line up in one continuous shadow. But only for that one day, if I miss it I'll have to wait till the next equinox in spring.

References:

Sunwheel project at the University of Massachusett's Sunwheel Project

"Rain Sticks" CS#10

2005-02-19T18:15:00.000-08:00

Coyote Science Activity 10

Rain sticks
Posted by Hello

Rain Sticks
By Bob Culbertson 2005 ©

Make rain-sounds any time using a few simple materials. The mixture of many different sound frequencies can make a very soothing effect and it can also help cover loud annoying noises too. The hardness, weight and shape of the seeds make a difference as well as the size of the mailing tube.

Try to invent a way to let the seeds trickle slowly when the covers are placed on the ends of the mailing tube. Not easy but can be done, think about what you need to do.

Materials:

Mailing tubes large and small, caps optional

Round wooden toothpicks

Two cups that will fit over the end of the tube

White glue

Tools:

Ice-pick or long nail slightly smaller in diameter than toothpicks

Various types of seeds, corn, pearl barley, buckwheat, milo, beans even beads or BB's

What to do:

Poke lots of holes in the sides of the mailing tube and push a toothpick in each with only a bit of it outside the tube. Keep it in with a daub of glue. When dry set the tube upright in one of the cups and use the other cup to slowly pour in some seeds. The seeds hitting the toothpicks will make a pleasant sound like rain falling on a roof. Try different size tube, more or less toothpicks and different seeds. Which sound better?

References:

This activity adapted from an interview of Mr.Yoshifusa Ogawa by Angela Jeffs for the Japan Times Dec. 24, 2000 website.

"Santa -- sorry Ogawa -- then handed me my Christmas present. The dried stem of a plant ("sesaragi"), filled with soba (buckwheat), which when turned upside down trickles with sound. "Deaf people can feel the vibrations." And the raised white dots? Toothpicks, he answered, inserted from outside into the center; when the soba falls, it falls against and between the picks, so creating the sound effect."

"Do the Tallywalker" CS#9

2005-02-19T10:44:00.000-08:00

Tallywalker CS#9
Posted by Hello

Coyote Science Activity 9

Do the "Tallywalker"

Pun (dit) Intended!

By Bob Culbertson 2005 ©

About a 150 years ago British secret agents, disguised as Buddhist pilgrims visiting holy sites or Moslem traders peddling their wares, were traveling the roads, trails and mountain passes of the forbidden countries surrounding India. These agents, hand picked native Indians secretly trained in the surveying arts, had a few carefully disguised instruments, a measured pace and the knowledge that they would be killed if anyone discovered their true purpose. Known by a letter/number combination, code name or simply as "pundit" (learned or wise one), they were expected to spend years on a mission and if captured would receive no help from the British government. Surprisingly some survived and the information they gathered slowly filled in the military's maps of central Asia and China. The classic adventure story "Kim" by Rudyard Kipling, set in a time many years after these surveyors', touched upon their lives.

Even without a miniaturized sextant, secret compartments, boiling point thermometer (for determining altitude), compass and constant danger we can still collect useful information on a hike. The equipment we'll need is simple and cheap: a "tallywalker" (to keep track of how many steps you take), map and a pencil.

For the tallywalker you'll need 10 small beads, 4 larger beads and a long shoelace. Double, or triple, strand the shoelace (so the beads don't slip too easily) and tie a big knot in the center, thread the 10 small beads on one side of the knot and the 4 big ones on the other. Tie the ends together to make a large loop with small beads on one side and large ones on the other that can be slid up and down the string. Using it is easy too. Every 100 paces move a small bead to the end of the loop, when you've moved all 10 small beads then move 1 big bead to the end and start on the small ones again. If you keep doing this until you've moved all the beads you'll have a tally of 5000 paces (10 small beads at 100 paces each = 1000 paces) + (4 large beads at 1000 paces each = 4000 paces) = 5000 paces total.

Practically every park has a simple map of its hiking trails and everyone with a tallywalker will need one. Any kind of pen or pencil and a flat surface to write on would be handy, the brim of a hat will do fine, but not necessary. Now you've got everything you need so let's give it a try:

Assemble at the starting point, whether it be the parking lot or trailhead, and make sure everyone is ready, return time decided upon and equipment checked (it would be good to have a few extra tallywalkers, maps and pencils available). Everyone makes a mark on the map as to where they start, decide where will be the first check point, take the tally in one hand, and GO!

Everyone keeps track of their own paces and at the first check point they write the tallywalker's number on the map. Reset the tallywalker to zero then start pacing off again to the next checkpoint and so on until the return point is reached. Each map will have marks on the trail with a number beside each that shows how far you've traveled measured in paces.

When you're ready to return reset the tallywalkers and start counting again. If you go back the same way you came then everyone will know about how far it is to the next checkpoint.

Some hints: Don't have a park nearby? City streets work fine too. Make the checkpoints fairly close together at the beginning of the hike, that will give everyone a chance to figure out how to use the tallywalkers and maps. Everyone's pace is different so individual maps are needed.

If you want to calibrate your pace go to a 500 meter track at a local school and walk around it a couple of times while using the tallywalker (2 times around the track is 1 kilometer, about 1000 yards). When returning you can set the tallywalker to the last count and subtract paces but this is harder to do (addition is always easier than subtraction) and not recommended. If you mess up a count just start over again at the next checkpoint. The checkpoints would be great places to take a break, give a demonstration or tell a story (maybe about pundits?). I certainly would want a tallywalker if I were blind or walking at night. Why?

References:

"Trespassers on the Roof of the World: The Race for Lhasa", by Peter Hopkirk, Oxford University Press, 1983

"Pollen Cards" CS#8

2005-02-17T04:46:00.000-08:00

Coyote Science Activity 8

Pollen cards
Posted by Hello

Pollen Cards
(It's everyone's business!)

By Bob Culbertson 2005 ©

Grains of pollen are unique for each plant and are almost indestructible. Police investigators use pollen to learn about crime scenes and scientists about natural environments, ancient or modern. But they need collections of pollen to compare an unknown sample to.

Here's an easy way to get started with your own collection.

Materials

Old business cards

Roll of clear tape

Garbage bag tie, or string

Tools:

Hole punch

Pencil

Nice to have access to:

Microscope 100 to 200 power maximum

Health food bee pollen

What you want to do:

Punch 2 holes in each of the business cards, one in the center and another in the corner. Try to make them all the same. Now put the tie, or string, through the corner hole of all of the cards so that they are held loosely together like keys on a key ring.

When you want to collect some pollen tear off a piece of clear tape and place it over the hole, then dust the exposed sticky side with pollen and cover it with another piece of tape. Use the pencil to write down the date, location and name (or description) of the plant you got it from. Later look at the sample with a microscope and draw a picture of it on the card too. There are some more advanced techniques for using the microscope, ask me about them.

A good test of your identification skills would be to get pollen from a health food store then try to identify the type of pollen the bees collected.

References:

Pollen information at: The Department of Ultrastructure Research and Palynology )

"Rain Flowers" CS#7

2005-02-17T04:42:00.000-08:00

Coyote Science Activity 7

Pick up a few pinecones and you'll notice that some are tightly closed while the segments on others are spread apart and open. This has to do with the amount of moisture in the cone and gives the pine tree some control over when it drops its seeds. As long as the cone is green and has moisture from sap in it the cone stays closed and the seeds continue to grow but when the seeds are fully developed the sap no longer enters the cone and it begins to dry out. As it dries the cone's segments begin to separate until they are far enough apart to allow the pine nut to drop out to be transported by wind (if the seed is equipped with wings) or buried by animals such as jays or chipmunks.

Later the now empty cone drops to the ground to be picked up and made into Rain Flowers by humans.

Materials

Pine cones

Popsicle (tm) sticks (also known as "craft sticks")

Colored markers

Waterproof glue (this might be tricky, water based glues work fine when dry but dissolve when wet)

Stiff wire (coat hangers if you can find them)

Tools:

Pliers

Spray bottle of water

Masking tape

Rags to clean up with

What you want to do:

The object here is to glue short flat colored sticks (Popsicle sticks) on to the segments of a pinecone. After the glue is dried the cone will look like a funny colored flower that will open up when dry but will close up when rained on. To make them easier to use a stiff wire is used for a stem.

How to do it:

Dry the pinecones so all the segments are open. Cut off a 2 to 3 foot length of wire and bend a hook in one end that will fit between the segments at the stem end of the cone. Pinch the hook together to hold the cone tightly.

About 1/2 hour before starting this section mist the cones with the spray bottle, this will make the cone segments close up tightly.

Color the sticks with different designs or just solid colors, only on one side is best but do whatever you like to make them interesting. When dry break them in half so you have a pile of stubby colored sticks.

Set a closed up cone on the work table top stem side down so the pointy end is up (taping the wire to the table top helps). At the broken end of one of the sticks spread a little glue on the uncolored side, only about 1/4 inch of the end needs glue on it. Hold the round end of the stick in your hand with the glue and uncolored side facing the stem of the cone and gently push the stick between one of the segments. Position the glued end over one of the segments and go on to the next one.

When you've put in about 10 or 12 sticks set the Rain Flower aside to dry and go on to the next cone. Leave the Rain Flowers overnight so the glue dries well.

How to use the Rain Flowers:

Poke the wire stem into the ground and wait for a bit of rain to make the Rain Flower close up. If you can't wait 3 or 4 months then a hose or spray bottle works too. They're fine indoors too but careful with the water please!

Variations on a theme:

Try making a turkey or peacock with a tail that folds up when it's pinecone body is dampened. How about a sun-shade that closes up when it rains to let in more light?

"How to Measure a Meter" CS#6

2005-02-15T04:35:00.000-08:00

Coyote Science Activity 6

Over 200 years ago a famous French scientist (actually Huygens was Dutch but much admired in France and was persuaded to work there) wanted to base a measurement system for the "Age of Reason" on a universal constant but the only convenient measurement accepted worldwide was the second. So he suggested that a new linear measurement (later known as the "meter") be based on the length of a pendulum’s string that would swing 1 time per second (a complete cycle in 2 seconds ).

Unfortunately, it was soon discovered by other scientists that a pendulum's swing depends on the Earth's gravity, which would be fine except gravity isn’t constant and varies from place to place. A new universal basis for the meter had to be found which produced the cumbersome "one millionth of the distance between the North Pole and the equator", bars of platinum locked in vaults and finally defined as 1,650,763.73 wavelengths of the red-orange radiation from krypton-86. Not as satisfying as a simple piece of string with a weight tied on its end but the relationship between the second and meter still exists.

To show this relationship between the meter and second you’ll need:

Long piece of string

A heavy weight (bead, fishing weight, key, etc.)

Ruler or meter stick

And a watch,or clock, with a second hand

How to do it:

Attach the weight to one end of the string and tie a knot 1 meter from the center of the weight, in the other end. Pinch the knot between your fingers and let the pendulum swing freely, one swing equals one second, count the swings and check it against a watch. It may not be too accurate but doesn't have batteries to replace.

References:

"The Mapmakers: The Story of the Great Pioneers in Cartography From Antiquity to the Space Age", by John Noble Wilford, New York: Vintage, 1982

"General College Chemistry", fourth edition, C. W. Keenan and J. H. Wood, Harper & Row, New York

"Make Marble Microscopes" CS#5

2005-02-12T19:45:00.000-08:00

Coyote Science Activity 5

Marble microscopes
Posted by Hello

Make Marble Microscopes

It's easy to make a simple microscope with only a clear marble, 2 business cards, a hole punch and staples or tape. This microscope will be similar to those made by an amateur scientist that lived over two centuries ago named Antoni Van Leevanhoek. He was able to make ones that would make objects appear about 200 times larger, enough to allow him to see bacteria. A marble microscope will magnify only about 50 times, but is a lot easier to make.

Place one business card on top of the other and line up the edges then staple, or tape, each long end close to its edge. Punch a hole in the center of the two cards and slide the marble between them so that it’s trapped in the holes.

Hold the microscope close to your eye and while looking through the marble. bring something very close to the other side (like your finger). Looks pretty big doesn't it? Wonder why? Here's a short explanation of what happens:

Human eyes are made to accept light from things far away, so anything closer than about 25 cm usually isn't seen clearly. Try this by slowly moving a pencil away from your eye until it looks clear. Measure this distance, then move the pencil closer until it's half the distance. If you could see it clearly the pencil would look twice as big because it's at half the distance from your eye. You need something to make the pencil look clear even when close.

That's just what a magnifying lens does, its special shape bends light. Hold the lens close to your eye and bring the pencil near enough to see it clearly. Measure the distance from the lens to the pencil and compare it to the closest distance you can see it without a lens (Remember 1/2 the distance = 2 times larger, 1/4 the distance = 4 times larger, etc.). 50 times larger would mean a distance of about 1/2 cm, 200 times larger would be about 1 mm! Hope you like to get close to the things you're looking at.

Materials:

2 business cards, playing cards or other stiff paper

1 clear glass marble (found at arts and crafts stores)

Tools:

Stapler or tape,

Hand held paper hole punch

References:

"Microscopes Probe the Imperceptible", Thomas V. Highness, Laser Focus World, March 1995, Vol. 31 No. 3

"Silent Talking" CS#4

2005-02-12T16:54:00.000-08:00

Coyote Science Activity 4

Charts courtesy of the Indiana Institute on Disability and Community

Trying to communicate over long distances, underwater and in noisy places has always been difficult, at least until high tech cell phones and handheld receiver/transmitters were developed. However, with very little equipment 2 or more people can "talk" without sound. This silent talking is called sign language.

Materials:

Binoculars or telescope (even a video camera with zoom lens!)

Finger spelling chart (sample charts used with permission from the Indiana Institute on Disability and Community)

Small pad of paper

Pencil with strap

Several large rubber bands or string

How to do it:

Tip! It's important to practice in front of a mirror before trying to sign with friends.

S!trap the pad of paper on your thigh so it will be easy to write on while reading signs, tie the pencil to your wrist with about 1 foot (30 cm) of string so it won't be lost. Sit facing your partner and practice signing short messages, make abbreviations for commonly used words. Next try sitting across a park or parking lot while using binoculars to read each other's signed messages. Compare the recorded messages later to see how accurate you were.

In a classroom divide the students up into pairs with each member in different parts of the room or playground and see if they can sign messages without making a sound. Signing through a large glass window such as those in a cafeteria would be a challenge.

Have fun! (But quietly.....)

"Find the Tiger" CS#3

2005-02-06T19:06:00.000-08:00

Coyote Science Activity 3

Courtesy of Gary Stolz, US Dept. of Fish and Wildlife

Next time you're hiking kick up a little dust, watch it drift in the breeze, and try this activity:

The wind carries dust and hundreds of the invisible smells that surround us. A hungry tiger would use these smells, or scents, to find their prey in dense jungle growth and only depend on its sight when attacking.

Most cats, and a tiger is a cat (and a cat is a tiger?), prefer to either stalk or ambush their prey. The method used depends upon the tiger's knowledge of the terrain, the movement of the prey and the direction of the wind that brings the scent. If the wind blows the scent in the same direction as the prey's movement, then the tiger will try to find a good place to wait in ambush. If the wind blows the prey's scent behind it, then the tiger will sneak up (stalk) from that direction.

Wind borne scents are used by the prey animal too. By knowing the direction of the wind the prey will know from where danger will come and will be ready to escape or fight, either of which will ruin the tiger's hunt and the chance for an easy meal.

So, look at the dust and decide where the tiger is. Are you walking into an ambush? Will it stalk you from behind? Your human nose isn't much help but you have the most powerful brain in nature. Use it!

Why would a dog with its big nose but small brain be of great help to early humans?

References:

"Man-Eaters of Kumaon", by Jim Corbett.

"How to Make a Bamboo Whistle" CS#2

2005-02-06T18:20:00.000-08:00

Coyote Science Activity 2

In case you've never made a bamboo whistle here's the way I do it:

You'll need at the very least a very sharp knife but it's sure a lot easier to do if you also have a hacksaw blade and a wood file (a shoemaker's, or cobbler's file is perfect). Cut off a section of bamboo about 10 inches long and about 1 inch in diameter, it can be open at both ends or closed at one. About 1 inch from one of the open ends make a 1/4 inch deep cut across it. With knife or file make a ramp that extends about 3/4 inch from the saw cut and points toward the other end of the bamboo (looks something like this \I from the side). Looking from above, the cut now looks something like a "U" with the bottom of the U being very sharp looking. Set the bamboo in the hot Sun to dry and harden for a day or bake in the oven for a bit. When the bamboo is dry and hard clean any loose paper-like stuff out of the bottom of the "U".

To make the mouthpiece cut off a piece of soft wood about 1 inch long and shape it so it slides into the open end of the bamboo above the U cut. I should be rather tight but not tight enough to split the bamboo's sides, you can pin it later if it's too loose. Now comes the tricky part, you must cut another ramp along the length of the plug which is about an 1/8th inch on one end (the end where your mouth will blow air into the whistle) narrowing down to about 1/16 in on the end where the U cut is.

Slide the plug into the bamboo and blow softly down the hole in it. There should be a whistle sound but if not then try sliding the plug in and out of the bamboo slightly or rotating it a little. If that doesn't work try shaving a bit off the plug's ramp, with knife or file, to make it bigger and try it again it takes some practice to get it right.

Once the tone sounds good then you may have to glue the plug in place with a dab of white glue or drill a small hole through the bamboo and into the plug slightly and pin it in place with a round toothpick and glue.

I think the way it operates is something like this:

When you blow into the hole cut along the side of the plug the air speeds up moving from the wide end to the narrow end. When this high speed air finally leaves the end of the plug it gets split by the sharp bottom of the U cut which creates
lots of turbulence (small packets of different amounts of energy in the compressed air). Normally the packets would just recombine and you wouldn't hear anything but the 9 inches of bamboo tube beyond it traps the energy of certain packets (called frequency or tone) and adds them up to make a single tone (whistle) while the others just go away never to be heard from again.

Oddly enough this is the same thing that happens when you just use your mouth to whistle. The air leaving your pursed lips creates turbulence and the shape of your mouth cavity behind the lips picks out which sound you like. Try it and you'll see.

"Three ways to use binoculars" CS#1

2005-02-06T09:54:00.000-08:00

Coyote Science Activity 1

3 way binoculars
Posted by Hello

Three Ways to Use Binoculars
(Should they be called "Tri-oculars" then?)
By Bob Culbertson 2005 ©

Slipping a pair of binoculars and a hand lens or magnifying glass into our pocket before going outdoors should be second nature. They can expand our world not only to great distances but also to those of the very small. Here’s a couple of more things you can do with them:

Following a darting bird through tree branches with binoculars can be almost impossible. Instead of being frustrated try using only one eye to look through the binoculars while the other eye follows the action. Using both lenses gives a better feel for depth and distance but isn’t really necessary for identifying animals or following their movements. It will still take some practice before your brain will separate the two images but soon you won’t even notice it.

If you want to look at insects on the ground, without laying on your belly, or a humming bird’s nest in poison oak, without regretting it later, then give this trick a try: Hold your hand lens, or magnifying glass, between your eye and the eyepiece of one side of the binoculars then look at the ground about 3 meters away and adjust the focus until the dirt is as clear as possible. You’ve just made a short range telescope! You’ll find that with a more powerful lens you’ll be able to check out the scuff marks on the toes of your boots but most any type will let you comfortably watch wee beasties go on with their lives undisturbed (and you’ll enjoy their company but not their companionship).

Forgotten to bring along a hand lens? Don’t worry, just turn the binoculars around backwards and look through the field lens while bringing the object to be looked at close to the eyepiece. It works fine as a magnifying lens but takes a little getting used to.

References:
Special thanks to Ron Nadeau, Park Ranger OCHBP Southern California.