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Fifteen Quick, Attention-Grabbing,

Never-Fail, Inexpensive Science Demonstrations!

Always practice the demonstrations before presenting them to a live audience so that they truly are “Never Fail!”

Written and Compiled by: Barbara J. Shaw Ph.D.

Colorado State University Extension 4-H programs are available to all without discrimination.

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Physics (5 demonstrations)

Three Laws of Motion – First Law – Inertia

Demonstration #1: The Table Cloth What you need (one set):

Table (smooth edge) Tablecloth Heavy metal silverware Heavy plate (stoneware is perfect) Heavy drinking glass (glass)

Broom and dustpan (just in case) Plastic ware Plastic plate Plastic cup

Introduction:

The First Law of Motion – Inertia – An object at rest remains at rest, and an object in motion continues in a straight line, at a constant speed, until a force acts upon it. This law is much easier to demonstrate using “an object at rests remains at rest until a force acts upon it.” If you do any demonstrations in microgravity (like on the International Space Station) then by all means, demonstrate “an object in motion continues in a straight line, at a constant speed, until a force acts upon it!” The forces on Earth (gravity and friction from the air molecules) immediately act on any object in motion.

Directions: Put the tablecloth over the table. Set the table with the plastic ware, plastic plate, and

plastic cup. With a flair and flourish, grab the edge of the tablecloth, and face your audience. Ask

what will happen when you jerk the tablecloth. Wait for responses. Ask for a drum roll. Jerk the tablecloth. The plastic ware, plastic plate, and plastic cup will fly everywhere. Act embarrassed. Put the tablecloth back over the table. Reset the table, but this time use the metal silverware, stoneware plate and glass cup

(showing the audience that it is indeed breakable) Ask for a victim – oops, I mean volunteer. Whisper to your volunteer that when they jerk the tablecloth, they need to jerk fast and

down towards the floor. If they jerk up, it will flip the table setting. Ask the audience what will happen now. Direct your volunteer to jerk the tablecloth. Ta Da! Discuss the results.

Explanation:

The first law of motion, Inertia, tells us that an object will stay at rest until a force acts upon it. The objects are the place setting items. In the first part, everything goes flying, because the forces of friction (tablecloth rubbing against the place setting) acts much more quickly because the mass of those items is very low. When you use the heavier

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place setting, it takes longer for the forces of friction (tablecloth rubbing against the place setting) to act on them. The difference between the two place settings is because of momentum. Momentum is a property of a moving object by that determines the length of time required to bring it to rest or start it moving when under the action of a constant force. It takes longer for a semi-truck to accelerate to 35 mph than you in your car. Your car is much lighter (relatively speaking) than the semi. Same holds true for stopping. You can stop in a much short distance that it will take the semi.

Three Laws of Motion – Second Law – F=ma Demonstration #2: The Turkey Baster Bulb

What you need (1 for every team of partners):

baster bulbs ping pong balls

heavier balls the same size as ping pong balls

Introduction:

The Second Law of Motion – F=ma – This law is described by a mathematical equation, although everyone completely understands it.

F = force (something that pushes or pulls on an object) m=mass (weight is the mass pulled down by gravity; weight can change

depending on the planet, but the mass remains the same) a=acceleration (the increase or decrease rate of travel of an object; note that a

negative number indicates that the object is slowing down) The harder you push a toy car, the farther it will go. If you don’t push it as hard, it won’t go as far.

Directions: With flourish and flair, place the ping pong ball into the top of the baster bulb. Ask the audience what will happen if you barely squeeze the bulb. Wait for responses. Barely squeeze the bulb. With flourish and flair, place the ping pong ball into the top of the baster bulb. Ask the audience what will happen if you squeeze the bulb with all your might. Wait for

responses. Pretend that you are going to squeeze the bulb but don’t. Instead, stop and look at the

audience. Ask them if they would like to try this out for themselves. Ask everyone to wait until

everyone has the supplies. NOTE OF CAUTION: If you try to push the ping pong ball into the baster too far, it will

get stuck inside. Direct the audience members to just make a seal, and not push too hard. Distribute the bulbs and ping pong balls. If your participants are working as partners,

direct them to alternate squeezing and retrieving the ping pong ball. Allow ~5 minutes. Get everyone’s attention. Ask what will happen if they use a heavier ball than the ping

pong ball. Wait for responses. Exchange the ping pong balls for the heavier balls. Allow ~5 minutes. Discuss the results.

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Explanation:

It is really intuitive. I have a turkey baster bulb, and I put a ping pong ball in the opening. What will happen if I barely squeeze the bulb? The ping pong ball was barely pop out of the baster. If, instead, I squeeze the bulb as hard as I can, then that bulb will go flying out. Now, instead of a ping pong ball, I use a bowling ball (assuming that I can find one the same size as the ping pong ball). Squeezing as hard as I can, which ball will go farther? The ping pong ball! This equation tells us why (using pretend numbers):

F (force) = 12 m (mass) = 2 (light object) a (acceleration) = ?

F = m x a 12 = 2 x ? Acceleration = 6

How about this? F (force) = 12 m (mass) = 4 (heavier object) a (acceleration) = ?

F = m x a 12 = 4 x ? Acceleration = 3

You can see from the numbers above, that a lighter object will accelerate more (and thus go farther) than the heavier object. The force remains the same. You can plug in real numbers to figure out the force applied, or if you know the force, you can figure out either how far will the object travel, if you know the mass, or determine the mass if you measure how far it travels. I love math!

Three Laws of Motion – Third Law

Demonstration #3: Balloon Cars What you need (1 for every team of partners): Balloons Bendy straws

Scotch tape Large toy cars

Introduction: The Third Law of Motion – Action/Reaction – For every action, there is an opposite, but equal, reaction. The meaning of the third law is easier to understand if you replace the words “action” and “reaction” with the word “force.” Remember, a force is something that will push or pull an object. Directions:

Set out the supplies. Tape the straw to the car with the long end pointed towards the rear of the car, and the short end by the front of the car.

Blow up the balloon and twist the neck so that the air won’t escape. Ask the audience what will happen if you attach the balloon to the straw and let it go.

Stop. Ask the audience if they would like to do this for themselves. Ask them if they would like to try this out for themselves. Ask everyone to wait until

everyone has the supplies.

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Distribute the cars, straws, balloons, and tape. If your participants are working as partners, direct them to alternate squeezing and retrieving the ping pong ball. Allow ~10 minutes.

Discuss the results. Troubleshooting: Be sure that the straw is taped correctly, with the long end pointed

midway between the rear wheels of the car. Be sure that the balloon neck is twisted so that they participants can get it sealed around the balloon before releasing the air.

Explanation:

Rockets leave Earth’s gravity because of the third law of motion. The action is the expanding oxygen and hydrogen gases as they are ignited, and the reaction is the rocket is propelled towards the sky. In our experiment, the action is the participant blowing air into the balloon, and the reaction is the car propelled by the thrust of the air leaving the balloon. If the participant blows up the balloon until it is about ready to burst, the car will go a lot farther (assuming that the straw has been correctly taped in the correct direction. If the participant barely blows up the balloon, the car won’t go very far.

Light

Demonstration #4: Colors in White Light What you need (1 for every participant):

Flashlight Red, green, and blue gels Masking tape

White wall or screen in darken room Prism Scissors

Introduction: Primary Colors of Light – What are primary and secondary colors? What are the colors in a rainbow? Before the demonstration:

Set aside one flashlight for the prism. Cut out red, green, and blue gels using the diameter of the flashlight’s plastic window. The gels should be equally distributed among all the flashlights. For example, if you have 16 flashlights, 5 will get red gels, 5 will get green gels, 5 will get blue gels, and one has no gel. Dismantle the flashlights, and place one gel inside the plastic window, and reassemble. Repeat until all but one flashlight have the gels.

Directions:

On the white wall or screen, put a small piece of masking tape. Turn out the lights. Ask the participants what happens when you shine a light though a prism. Wait for

responses. Shine your flashlight though the prism. You will need to turn the prism until you see the

rainbow colors. Focus the rainbow until tight and bright. Ask participants what makes the colors. Wait for responses.

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Ask students to leave the flashlights switched off until you give them directions. Distribute 1 flashlight per participant. Announce to the group the color of the flashlight.

Point to the piece of masking tape (you may need to shine your flashlight on it). Remind the participants to keep the flashlights switched off.

When you give them permission, you would like them to shine their flashlight, aiming it directly on that piece of masking tape.

Before you give permission, tell the participants to observe the colors that they see. Give permission to turn the flashlights on. You will need to refocus the group to aim

their light directly on the piece of masking tape. When they finally achieve that fleeting success, ask what color of light is on the very center of the masking tape (white light).

Standing next to the light, hold your hand up, and about 6” away from the masking tape, so that your hand will cast shadows.

Wait for the oohs and aahs! Allow participants a minute to make the room dance with the three colors of light, and

then direct them to turn off the flashlights. Discuss the results.

Explanation:

Visible light appears white, but actually is made from the rainbow of colors (ROY G. BIV – Red, Orange, Yellow, Green, Blue, Indigo, and Violet). When they are all mixed together, the light appears white. As light travels though a solid, transparent object, like the prism, the different colors travel differently, and we can see them separated on the other side of the prism (or raindrop). The primary colors of pigments, or anything that is made from atoms, are red, yellow, and blue, and the secondary colors are orange, green, and purple. Most children know that to make purple, they need to mix red and blue. To make orange, they mix red and yellow, and to make green, they mix yellow and blue. Light is different. It is not made from atoms, but it is a form of energy. The primary colors of light are red, green and blue, and the secondary colors are magenta, yellow, and cyan. With the prism, we are able to separate each color of light, and with the flashlights, we put the primary colors together, and we see white light. Sir Isaac Newton was the first person to determine that the colors we see are not inside the prism, but made up of the light itself.

Sound

Demonstration #5: Groan, Squawk, Gong, and Whir! What you need (1 set made ahead):

Bullroarer (directions below) o Thin ruler with hole in one end o String o Rubber bands o Plastic spoons

Quacking Duck (directions below) o Heavy duty plastic cup o Nail o String o Sponge o Water

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What you need (1 for every participant): Heavy duty plastic cup String about 18” long Large paperclip Large nail

Large balloon Hex nut

Introduction:

Sound is produced by compression waves (waves that travel like an accordion). Those waves strike your eardrum, and that membrane starts to vibrate. Those vibrations cause an inner membrane to vibrate in a chamber filled with liquid, your inner ear. Those vibrations are translated into the liquid. Tiny “hairs” in that inner chamber move from the vibrations translated in the liquid, and your brain interprets that as sound. You can use two of these experiments as demonstrations or to get attention from your audience. The other two are quick activities for your participants to make and take.

Before the demonstration:

To make the Bullroarer, tie the string (about 3 feet long) through the hole of the ruler. Stretch the rubber band lengthwise over the ruler. To operate, twirl in front of you or over your head (like a lasso). If it isn’t very loud, twirl in the other direction. Change speed. Optionally, you can make different sizes, including one as small as a plastic spoon. Tie the string by the bowl of the spoon. Stretch a rubber band lengthwise over the spoon. Twirl in front of you or over your head. Is the sound the same? Higher or lower? Louder or softer? To make the Quacking Duck, carefully punch a hole in the cup with a nail. Thread a string (about 2 feet long) through the cup. Tie one end of the string to a large paperclip. This needs to be on the outside of the bottom of the cup. The string should be hanging out of the cup. On the other end, moisten and tie a sponge (about 1”x2” piece works perfectly). With a moist sponge, pinch the string inside the bell of the cup and pull down the length of the string. As the string becomes wetter, the sound gets louder.

Directions:

Twirl the Bullroarer for attention. Quack the Quacking Duck. Ask, what is common about these two sounds? Wait for replies. (Both are made from

vibrating air.) Beautiful Chimes – distribute plastic cups, string, paperclips and nails. Direct participants to up the cup with the bottom up. With the nail, carefully put a hole in

the center of the bottom of the cup. Thread the string through the hole. On the outside of the bottom of the cup, tie the nail.

On the inside of the bottom of the cup, tie the paperclip. Pull the string on the nail side, until all of the string is coming out of the bottom on the

outside of the cup. Direct participants to place their ear over the open end of the cup, and gently swing the

nail into a chair or table, listening to the sound. Wow!

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AND/OR Twirl the Bullroarer for attention. Quack the Quacking Duck. Ask, what is common about these two sounds? Wait for replies. (Both are made from

vibrating air.) Whirring Balloon – distribute balloon and hex nut. Instruct the participants to squeeze the hex nut through the neck of the balloon. Blow up the balloon about half full (WARNING – ONLY HALF FULL). Tie off the neck of the balloon. Holding the balloon in one hand at the neck, palm down and fingers and thumb extending

onto the balloon, start to make circular motions to move the hex nut in a circle on the inside of the balloon.

WOW! Discuss the results.

Explanation:

All sound is caused by vibrations. There are all kinds of different sounds because different materials vibrate differently. For the Bullroarer, the air passes through the holes at a faster speed than the air that is going around the ruler or plastic spoon. This causes the whirring, rushing air sound. The cup on the Quacking Duck amplifies the sound, which is caused by the vibrating string. The beautiful chime sound you hear from clanging the nail while listening in the cup is because the sound is traveling through solid (the string) rather than in the air. When you clank the nail without holding the cup to your ear, the dull clank is only traveling through the air. The difference in sound shows how much of the sound is lost in the air. Solids and liquids are much better at carrying sound waves. A hex nut has 6 sides, and these flat edges causing the hex nut to bounce inside the balloon. The whirring sound is made by the sides of the hex nut vibrating against the inside wall of the balloon.

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Chemistry (4 demonstrations)

There are some spectacular demonstrations in Chemistry, but they require specialized equipment and training to use them safely. If you are interested in some amazing demonstrations, I would

be happy to train you to produce smoke bombs, torches, fire and ice, and other cool stuff. The ones selected here are all kitchen chemistry and safe.

The Atom

Demonstration #6: What you need:

6 participants An audience Introduction:

Atoms are the smallest an element can be. A single atom of gold is a tiny, tiny, tiny piece of gold. If you break it in two pieces, it is no longer gold but particles. The particles make up atoms, but they are not elements. Particles have very cool names, like quarks, muons, gluons, and electrons. Atoms have 3 major parts. By adding energy to the atom, everything speeds up. When an atom becomes very energetic, it will change phase from solid to liquid, or liquid to gas, or gas to plasma. When energy leaves an atom, it slows down, and it can phase change from plasma to gas, from gas to liquid, or from liquid to solid.

Directions: Ask participants, “What is an atom?” Allow time for responses.

o Help to elicit the following: Protons Neutrons Electrons

o Ask for volunteers. You will need 6 people. 2 people are protons 2 people are neutrons 2 people are electrons

o Put the protons back to back o Put the neutrons back to back between the two protons o Ask the electrons to walk around the nucleus, as close to the nucleus without

touching. This atom is a neon atom because it has 2 protons. If it only had 1 proton, it would be a

hydrogen atom. The elements (the specific kind of atom) depend on the number of protons in the atom.

What happens when we add energy? Let’s see. The electrons are the only parts that can move. How would the nucleus respond? (Vibrate in place.) How would the electrons respond? (Run around the nucleus.)

Add energy to the system. Be sure to point out that as the electrons run around the nucleus, they have to move out farther than when they were just walking. The nucleus

Nucleus

Nucleus

Nucleus

Nucleus

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just jiggles faster. This does model electron movement away from the nucleus, but in quantum leaps rather than sliding. You can explain that by using the allegory of Star Trek transporters. Someone is on the platform, then they are on the planet. The electron is at a specific distance from the nucleus (called a shell), and when energy is added, it is transported to a shell further from the nucleus. How far depends on how much energy.

Remove the energy from the system. The nucleus stops jiggling and the electrons once again walk as close to the nucleus without touching.

Energy cannot be created or destroyed. When energy is absorbed by an atom, the energy is converted to kinetic energy (energy of motion). When it is given off, it can leave as heat, light, sound, electric, etc.

Explanation:

An atom has three major parts: The proton is made from three particles, two up quarks and one down quark held

together by strong nuclear forces. It has a positive charge (like the north pole of a magnet).

The neutron is made from three particles, one up quark and two down quarks, held together by strong nuclear forces. It doesn’t have any charge.

The electron is a particle. It has a negative charge (like the south pole of a magnet).

The other particles (like the muons and gluons) help with the structure of the atom.

The protons and neutrons from the nucleus of the atom. The electron travels around the nucleus really, really fast. The number of protons determines what kind of element the atom will be. For

example, an atom with 1 proton is hydrogen. An atom with 8 protons is oxygen. An atom with 79 protons is gold.

An atom will have the same number of electrons as it has protons. The atom can lose or gain electrons , and that is what drives many reactions.

Hydrogen, the simplest atom, has one proton and one electron, and 99.98% of all hydrogen atoms lack a neutron. Only in extremely rare cases, will it also have one or two neutrons.

All other atoms have at least the same number of neutrons as protons, but as the element gets heavier, it will have a greater number of neutrons than protons. For example, uranium has 92 protons, but it will have an average of 146 neutrons.

Mixtures and Reactions

Demonstration #7: What you need (1 for every participant):

Individually wrapped brownie Napkin

3 oz Dixie cup Trail mix

Introduction:

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Mixtures and reactions are two important ways that atoms and molecules interact. In a mixture, the individual atoms or molecules can be separated, but in a reaction, they cannot be separated because they have all become bonded.

Directions: Most people are confused about what chemicals are. Ask your participants, “What is a

chemical? Allow time for responses. Ask participants to raise their hands if they are wearing a chemical. Allow time for

responses. Tell them that if their hand is not up, it means that they are naked! All clothes are made from chemicals!

Ask participants to raise their hands if they eat chemicals. Allow time for responses. Tell them that if their hand is not up, it means that they don’t eat! Pizza and brownies are made entirely from chemicals. In fact, all food is made from chemicals.

Ask participants to take a deep breath and hold it. Ask them to let it go. Ask if they breathed in any chemicals? Yes, oxygen they need for life is a chemical. So are poisons, and toxins, the Earth, and in fact every participant is a big bag of chemicals in the solid, liquid, and gas states of matter.

Chemicals are atoms and molecules (more than one type of atom bonded together). Fill one 3 oz cup with trail mix for each participant and one for yourself. Instruct everyone to not touch the food until directed. Distribute 1 brownie, trail mix, and napkin to each participant. Ask, “What are the ingredients in trail mix?” Allow time for responses. Ask everyone to pick out one pretzel and one pretzel only, and eat it. Ask everyone to pick out one raisin and one raisin only, and eat it. The cup of trail mix represents a mixture of chemicals. It is possible to separate each

“molecule” from all the other “molecules.” Ask, “What are the ingredients in brownies?” Allow time for responses. Ask everyone to pick out the chocolate and the chocolate only, and eat it. Obviously they cannot remove the chocolate because a chemical reaction has occurred,

and the chocolate has now bonded with the eggs, sugar, oil, and flour to make brownies. The brownie represents a chemical reaction.

Explanation:

Everything in the known universe is made from atoms, and therefore, is a chemical. Atoms are the smallest any element can be. They are made from smaller particles. Atoms can bond with other atoms and form molecules. These atoms and molecules make everything in the known universe from the oxygen we breathe, to the stars and planets.

Physical Changes Demonstration #8: Coke Geyser

What you need (1 set):

2 liter bottle of Diet Coke at room temperature (for best results)

Mint flavored Mentos (do not use the various other flavors)

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Introduction: What is a physical change? – Physical changes are related to the energy and states of matter of molecules. A physical change does not produce a new substance, but instead results in modifies the structure or produces phase changes (melting, freezing, vaporization, condensation, sublimation). Some examples of physical changes include crushing a can, melting an ice cube, and breaking a bottle.

Directions:

This demonstration is best if you can do it outdoors. If not, you will need a large container, like a cheap, inflatable kiddie pool, sponges, mop and bucket, and some cleaning solution (like Pinesol).

Place the 2 liter bottle of diet coke in an area where sticky grass won’t be a problem, or in the center of the kiddie pool.

Open the Mentos package, and remove 2 Mentos candies. Open the diet cola lid. Drop the Mentos candies into the opening of the 2 liter bottle and QUICKLY step away.

(If you use the kiddie pool, remember to step over the lip. Discuss the results.

Explanation:

Dr. Coffey, a physicist from Appalachian State University in Boone, North Carolina, conducted an experiment, examining the specific reasons for these eruptions. She tested different sodas, Mentos, and temperatures. The Mentos with the roughest surfaces, warm diet coke worked the best. Here are her results: The two key ingredients responsible for this physical change are potassium benzoate and aspartame in Diet Coke. If that is the case, then why doesn’t it explode when just opening a pop? That has to do with the physical structure of the mint Mentos (which are much rougher than the flavors of other Mentos). Think geometry as the answer. The rough surface on the Mentos reduces the work required for bubble formation, allowing carbon dioxide to rapidly escape from the soda. The physical structure of the Mentos, therefore, is the most significant cause of the eruption.

Chemical Reactions Demonstration #9: Elephant Toothpaste (kid friendly)

What you need (1 for every participant):

3% hydrogen peroxide Dawn dish detergent 2 empty 20oz plastic water bottles ½ cup of warm water Plastic tray or cookie sheet

Package of active yeast Food coloring Sponges to clean up the mess

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Introduction: What is a chemical reaction? – Chemical reactions occur on the molecular level, and they produce new substances. If you take a metal, sodium, and a poisonous gas, chlorine, bond them, you get table salt. Some examples of chemical reactions are fire, baking brownies, mixing vinegar and baking soda, and the sun giving us light..

Directions:

This demonstration is best if you can do it outdoors. If not, you will need a large plastic tray or cookie sheet to trap the mess.

In one water bottle, add the warm water and the packet of active yeast. Swirl gently to mix. Allow to sit for about 5 minutes to activate.

In the other water bottle, pour ½ cup hydrogen peroxide solution, ¼ cup dishwashing soap, and a few drops of food coloring into the bottle.

Gently swirl the bottle around to mix the ingredients. Place the bottle in an area where messy grass won’t be a problem, or in the center of the

tray or cookie sheet. When you are ready to do the demo, pour the yeast mixture into the bottle. Discuss the results.

Explanation:

The classic demo uses 30% hydrogen peroxide and potassium iodide, which are not safe for kids, but is spectacular. If you would like to present this demonstration, I will be happy to train you and supply the chemicals. The elephant toothpaste demo is one of the most popular chemistry demos, in which a steaming tube of foam keeps erupting from its container, resembling a smooched tube of elephant-sized toothpaste. In this version (still very cool), the hydrogen peroxide (which is made with 2 atoms of oxygen and 2 atoms of hydrogen) breaks apart and reforms into water and oxygen gas. (For every two molecules of H2O2, 1 molecule of atmospheric oxygen and 2 molecules of water are formed). Yeast breaks apart the hydrogen peroxide so that it proceeds much more rapidly than normal. The dishwashing detergent captures the oxygen that is released, making the “toothpaste.” The food coloring colors the bubbles. Be careful when you touch the bottle, because it will be hot. This demonstration is also exothermic, so heat is produced.

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Geo-Space Science Astronomy – Constellations

Demonstration #10 What you need (1 for each participant):

White envelope for each participant (be sure it isn’t a “security” envelope, but one that will allow light though

Paper punch Index card for each participant

Introduction: Star Light – Why can’t we see stars during the day? Our own star, the sun, is so close and so bright that it overwhelms the starlight that has to travel many light years to reach us. To identify the different areas of space, astronomers have divided the sky into constellations, similar to state lines. They are imaginary divisions. They are identified by the different random patterns of stars found within each constellation. Our ancestors played “connect the dots” and made pictures from these patterns. Directions:

Punch the holes of a constellation into the index card, and each index card has a different constellation punched. (See the next page.) Image captured 11/12/2010 http://www.zunal.com/webquest.php?w=11104

Put each of the index cards into an envelope, and seal. Make enough index cards with constellations for each participant. Make one copy of the next page for each participant. Distribute one envelope to each participant. To see the “stars” the participants hold their envelope up to the light. Distribute the constellation patterns to the participant. Each participant finds the matching pattern.

Explanation:

Stars make random patterns in the night sky, and it is the ability of humans to see patterns in chaos. If you look carefully at each of the constellation patterns, they don’t look anything like their names. If, however, you spend time looking at the stars, you can begin to pick out patterns among them. For example, let’s look closer at Taurus, the bull. The star pattern looks more like the letter “V” lying on its side. What if the point of the “V” is the bull’s nose, and the legs of the “V” are the bull horns? Now can you see the bull’s face? Each of the constellations can form pictures, and may different cultures have different stories in the stars by making different pictures from the random patterns. The envelope represents sunlight. We can’t see the stars and the patterns they make during the day, but they are still there, just like the index card inside the envelope. When you point the envelope towards light, you can see the stars emerge, just like dusk to night, when the sunlight is no longer on our side of the Earth.

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Astronomy – 3 – D Stars Demonstration #11

What you need

7 helium balloons Weights

Scissors Heavy string

Introduction: Flat Screen Stars vs. 3 – D Stars– The star patterns we see in the night sky look like they are all stationary and flat. Stars, however, are traveling at very high speeds and are sometimes hundreds of light years away from each other. If we could get into a space ship and travel to them, what would they look like? Directions:

Before your meeting, fill the 7 balloons with helium. You need an empty gym or a football field with little to no wind. Using the picture of the big dipper (Ursa Major, the great bear) ask the group to set up the

balloons into that pattern. Use the strings and weights to float them in the correct pattern. When everyone is satisfied, ask if all the stars are the same distance from us? No they aren’t. In fact, 5 stars are traveling in one direction, and the other 2 stars are

traveling in a different direction. Using the chart below, keep the same pattern from your location, but move them the

indicated number of feet away from you. (If you have room, double the distance.) Star Name Distance from the Earth Distance

Alkiad 123 123 feet Mizar 78 78 feet Alioth 80 80 feet Mergez 81 81 feet Phecda 83 83 feet Merak 79 79 feet Duhbe 123 123 feet

Explanation: The stars are so far away, and the light has to travel so far to get to us, that it appears that they are all at the same distance. Even though the stars are moving at great speeds, they also appear motionless in the night sky. If you are sitting on a curb watching cars go by, they appear to be moving really fast, but if you are sitting on a hill watching cars on a freeway a mile away, they appear to be moving very slowly. These stars are so far away, that they appear motionless! Captured on November 12, 2010 http://www.astro.wisc.edu/~dolan/constellations/constellations/Ursa_Major.html

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Meteorology – Climate Driver

Demonstration #12 What you need:

4 wide mouth cup Mason jars 2 – 16oz thermoses Very hot water (but not so hot that it

will scald you) in one thermos Very cold water in the other thermos

Red food coloring Blue food coloring Tray or cookie sheet Laminated sheet of paper

Introduction: What drives our climate? – The sun. Without the energy from the sun, there would be no life on Earth. The Earth is tilted 23.5 degrees. (See the Geology Demonstration #13). The energy from the sun strikes the Earth at different angles, and that chances the concentration of the energy. This means that the energy from the sun varies from place to place. Solar energy, therefore, heats the Earth unevenly. This uneven heat distribution is what drives our climate. In this room, where do you think is the warmest place (think about hot air does this, while cold air does that). Where is the coldest place in this room? Right hot air rises, while cold air sinks). This is convective energy. As the warm air rises, the air molecules spread out, and there are not as many of them, so, it forms low pressure underneath. As cold air sinks, there are more air molecules pushing down, and this forms high pressure. High and low pressure move winds and clouds around. Air is what state of matter? (Gas) Do you think this is true with liquids, too? Do you think that we can use liquid to examine this more closely? (Yes. This is true for any fluid molecule, even plasma, another state of matter that isn’t common on earth, but all the stars are in the plasma state, so 99% of the known universe is in the plasma state.) Directions:

As for 4 volunteers. Give the blue food coloring to the first volunteer, red food coloring to the second

volunteer, hot water thermos to the third volunteer, and cold water to the fourth volunteer.

Pair the hot water with the red food coloring. Pair the cold water with the blue food coloring. Place the tray out, and put one of the Mason jars in the center of the right side of the tray. Ask the blue food color volunteer to put 3 or 4 drops of food coloring into the Mason jar. Ask the cold water thermos volunteer to fill the Mason jar to the brim. Place another Mason jar on the tray. Ask the red food color volunteer to put 3 or 4 drops of food coloring into the Mason jar. Ask the hot water volunteer to fill the jar to the brim. Place the laminated sheet over the hot water.

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Turn the Mason jar upside down, making sure that the laminated sheet of paper stays in place, keeping all the water in the jar (be sure to practice this – very cool)

Carefully place the hot water Mason jar on the cold water Mason jar, lining up the lips of the openings.

Ask your audience where does hot air go? Where does cold air go? What do they think will happen when you let the hot and cold water mix?

Slide the laminated paper out, making sure that the jars remain aligned. Allow time for observations. Give a hand to the volunteers, and ask them to sit down. As for 4 volunteers. Give the blue food coloring to the first volunteer, red food coloring to the second

volunteer, the hot water thermos to the third volunteer, and cold water to the fourth volunteer.

Pair the hot water with the red food coloring. Pair the cold water with the blue food coloring. Place one of the Mason jars in the center of the left side of the tray. Ask the red food color volunteer to put 3 or 4 drops of food coloring into the Mason jar. Ask the hot water thermos volunteer to fill the Mason jar to the brim. Place another Mason jar on the tray. Ask the blue food color volunteer to put 3 or 4 drops of food coloring into the Mason jar. Ask the cold water volunteer to fill the jar to the brim. Place the laminated sheet over the cold water. Turn the Mason jar upside down, making sure that the laminated sheet of paper stays in

place, keeping all the water in the jar (be sure to practice this – very cool) Carefully place the cold water Mason jar on the hot water Mason jar, lining up the lips of

the openings. Ask your audience where does hot air go? Where does cold air go? What do they think

will happen when you let the hot and cold water mix? Slide the laminated paper out, making sure that the jars remain aligned. Allow time for observations. Discuss results

If you don’t have enough time to use volunteers, prepare the cold and hot Mason jars, and then ask the questions, and perform the tasks yourself. Explanation:

Hot water is less dense than cold water, and it will indeed rise, just the same as hot air is less dense than cold air, or hot plasma is less dense than cold plasma (relatively speaking, because the coolest parts of the sun are still about 8,000 degrees C!).

Oceanography Circulation

Demonstration #13 What you need:

4 wide mouth cup Mason jars 1 – 32 oz container (or larger)

water Yellow food coloring

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Green food coloring Table salt Mixing spoon

Tray or cookie sheet Laminated sheet of paper

Introduction: What is the oceanic conveyor belt? –Thermohaline (thermo means temperature and haline means salt) circulation is responsible for moving the ocean waters around the globe. Originally this very slow-moving convey belt (one lap around the world takes about 1600 years) was discovered when pollution dumped in the coastal waters of both the Atlantic and Pacific showed up in Antarctica. As the name thermohaline implies, it is the difference in density of fresh vs. salty water, and warm vs. cold water. Around both poles, glaciers melt, and they increase the freshwater content of the ocean. As ice freezes, it increases the salt content of the water remaining behind. The water there is very cold, and cold water sinks. (You can conduct Demonstration #12 to support this statement.) Warm water rises, and this begins to move the water, slowly. What do you think is denser, salty water or fresh water? Let’s find out. Directions:

As for 4 volunteers. Give the yellow food coloring to the first volunteer, green food coloring to the second

volunteer, and salt to the third volunteer. The 4th volunteer will pour the fresh water. Pair the salt water with the yellow food coloring. Pair the fresh water with the blue food coloring. Place the tray out, and put one of the Mason jars in the center of the right side of the tray. Ask the yellow food color volunteer to put 3 or 4 drops of food coloring into the Mason

jar. Ask the salt volunteer to fill the Mason jar half way, and add salt (a good pour from the

salt container – more than a tablespoon, and less than ¼ cup. Stir well to dissolve the salt into the water. Finish filling the Mason jar to the brim with water.

Place another Mason jar on the tray. Ask the green food color volunteer to put 3 or 4 drops of food coloring into the Mason

jar. Ask the fresh water volunteer to fill the jar to the brim. Place the laminated sheet over the hot water. Turn the Mason jar upside down, making sure that the laminated sheet of paper stays in

place, keeping all the water in the jar (be sure to practice this – very cool) Carefully place the fresh green water Mason jar on the salty yellow water Mason jar,

lining up the lips of the openings. Ask your audience what will happen? Where will the salty water go? What do they

think will happen when you let the fresh and salty water mix? Slide the laminated paper out, making sure that the jars remain aligned. Allow time for observations. Give a hand to the volunteers, and ask them to sit down.

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As for 4 volunteers. Give the yellow food coloring to the first volunteer, green food coloring to the second

volunteer, the salt to the third volunteer, and freshwater to the fourth volunteer. Pair the fresh water with the green food coloring. Pair the salty water with the yellow food coloring. Place one of the Mason jars in the center of the left side of the tray. Ask the green food color volunteer to put 3 or 4 drops of food coloring into the Mason

jar. Ask the fresh water volunteer to fill the Mason jar to the brim. Place another Mason jar on the tray. Ask the yellow food color volunteer to put 3 or 4 drops of food coloring into the Mason

jar. Ask the salt volunteer to fill the Mason jar half way, and add salt (a good pour from the

salt container – more than a tablespoon, and less than ¼ cup. Stir well to dissolve the salt into the water. Finish filling the Mason jar to the brim with water.

Place the laminated sheet over the cold water. Turn the Mason jar upside down, making sure that the laminated sheet of paper stays in

place, keeping all the water in the jar (be sure to practice this – very cool) Carefully place the salty yellow water Mason jar on the fresh green water Mason jar,

lining up the lips of the openings. Ask your audience what will happen? Where will the salty water go? What do they

think will happen when you let the fresh and salty water mix? Slide the laminated paper out, making sure that the jars remain aligned. Allow time for observations. Discuss results

If you don’t have enough time to use volunteers, prepare the fresh and salty Mason jars, and then ask the questions, and perform the tasks yourself. Explanation: Just like in the hot/cold water density demonstration #12, the fresh water rises because it is less dense. When the fresh water is on to, and the salty water is on the bottom, there is very little movement, because the lighter water is on top. In the ocean, as the water becomes colder, it sinks deep into the bottom of the ocean, and it is slowly pushed by new cold water sinking. The water slowly moves until it hits continents, and it becomes warmer as it approaches the surface. In a similar manner, as glaciers melt (and they melt because it is warmer), they add fresh water, which is lighter. This lighter water remains at the surface and is warmed by the sun. As fall approaches, the ice begins to form, and only fresh water will freeze, leaving a higher concentration of salt in the water at that point. This water is heavier, and it sinks, pushing that heavy cold water at the bottom of the ocean along. When it is winter at the North Pole, what is it at the South Pole (summer). When it is summer at the North Pole, what is it at the South Pole (winter). This difference in hemisphere temperature helps to move the water around. As the temperature gets colder, the water gets colder, it freezes and the concentration of salt water goes up. Cold plus salty is very heavy water. This is at one

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pole. At the other pole, however, the temperature is getting warmer, and the glaciers are melting. Warmer temperatures plus fresh water is very light. That is how thermohaline circulation works.

Geology – Reason for the Seasons Demonstration #14

What you need (1 for every participant):

Styrofoam ball Pencil Push pin Optional: globe

Lamp without the shade Extension cord Duct tape Masking tape (if you use a lamp)

Introduction: Why do we have Seasons? – When it is summer here, it is winter in Argentina. When it is winter in France, it is summer in Australia. Why is it warmer at the equator than it is at the poles? All these questions can be answered by looking at the spatial relationship between the Earth and the Sun. Our Earth is tilted 23.5°. If the floor is 0°, point to 90°. Point to 45°. Point to 23.5°. That is how much our Earth is tilted as it moves around the sun! Let’s figure out why we have seasons. Directions:

Before your audience arrives, place the lamp in the center of the room. Attach the extension cord, and lead to the closest outlet. Anchor the extension cord to the floor with the duct tape, so no one trips. In a large circle around the lamp, place 12, equally distributed “X”s on the floor with

masking tape. Each “X” represents 1 month. (If you have more than 12 participants, you can place 52 “X”s, one for each week of the year, or another variation on this to divide the circle into divisions of one year.)

When your participants arrive, introduce seasons. Distribute 1 Styrofoam ball and 1 pencil, and 1 push

pin to each participant. Stick the pencil into the South Pole. Based on the South Pole, estimate where on Earth

they are right now, and place the push pin to mark that spot. (Hint, we are in the Northern Hemisphere, and Colorado is located between 37° and 41° N Latitude.

Each person needs to stand on a masking tape “X.” Turn on the light and turn off the lights in the room.

90° 

~23.5° 

45° 

0° 

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Hold the pencil at 23.5° and point it towards the lamp (our model of the sun). This is summer in the Northern Hemisphere. Notice that the North Pole is completely in

the light. Does the South Pole have any light on it, or is it completely in the shadows. What month is this (June 21st, or summer solstice in the Northern Hemisphere and Winter Solstice in the Southern Hemisphere). Solstice is from Latin – Sol means sun and –stitium means stoppage.

Advance 3 “X”s moving in a counterclockwise direction. If each “X” is a month, what months is it now? (September 23rd in 2010, and the Equinox (Fall in the Northern and Spring in the Southern Hemisphere). Do not change the angle of the Styrofoam ball. The ball should not be pointed directly toward the lamp anymore, because the angle remains the same, but the ball has moved through space.

Do the poles get any light (they should both be receiving the same amount of light – equally. Equinox is from Latin – Aequus means equal and nox means night).

Advance 3 “X”s moving in a counterclockwise direction. If each “X” is a month, what months is it now? (December 21st in 2010, and the Solstice (Winter in the Northern and Summer in the Southern Hemisphere). Do not change the angle of the Styrofoam ball. The ball should be pointed directly away from the lamp, because the angle remains the same, but the ball has moved through space.

Do the poles get any light (the South Pole should be bathed in light, and the North Pole is completely in the shadows).

Advance 3 “X”s moving in a counterclockwise direction. If each “X” is a month, what months is it now? (March 20th in 2011, and the Equinox (Spring in the Northern and Fall in the Southern Hemisphere). Do not change the angle of the Styrofoam ball. The ball should not be pointed directly toward the lamp anymore, because the angle remains the same, but the ball has moved through space.

Do the poles get any light (they should both be receiving the same amount of light – equally.

The energy from the sun is responsible for climate, seasons, the thermohaline circulation of the ocean, and life being able to exist on Earth.

http://earthobservatory.nasa.gov/images/imagerecords/0/885/modis_wonderglobe_lrg.jpg Explanation:

It is the angle of the planet that determines the seasons. Graduates from Harvard University statistically answer this question incorrectly (stating instead that it was how close or how far we are from the sun in our orbit). Now everyone is smarter than a Harvard graduate!

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Biology Being Human

Demonstration #15 This series of demonstrations starts with no supplies, or pencil and paper required. Please note that one demonstration uses origami paper. Introduction: Our senses gather information about the world, and our brain interprets that information. Does our brain ever trick us? – In order to survive, we have certain abilities. For example, people are excellent at finding patters in randomness. We can make connect the dot pictures from the stars, even though there really isn’t any pattern in the stars. Our brain emphasizes edges – very important so we don’t fall off a cliff! The remaining demonstrations are a series of activities to demonstrate better how our senses work, and sometimes, how our brain incorrectly interprets our sensory input. Physiology examines how our bodies function. We can conduct all kinds of fun experiments on ourselves, to learn more about how we work. Directions for no materials required: Sausage Finger

Find a point on the opposite wall, and keep that point in focus (for example, a clock on a wall).

Point your two index fingers, and how your hands up at arm’s length between your eyes and the object in focus on the far wall.

Keeping the object in focus, touch your index fingertips together. Do you see the sausage between your two fingers?

Explanation: Our vision is binocular. The sausage is the image of our fingers that overlaps from each eye. If you focus on your finger, the sausage goes away.

How Accommodating! Focus at an object on the opposite side of the room. Point your finger at it, but keep the object in focus. Is your finger in focus? Focus on your finger. Is the object across the room still in focus?

Explanation: Our eye has a lens that is capable of focusing objects either close or far away. This is called accommodation. Our eyes do not have the ability to keep and object near and far in focus at the same time.

Jumping Jehoshaphat With your right hand, point at an object across the room. Keep both eyes open. Do not move your right hand, and with your left hand, cover your left eye.

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Remove your left hand. Do not move your right hand, and with your left hand, cover your RIGHT eye. Did your finger jump off the object? Which eye did it appear to jump?

Explanation: Almost everyone has a dominant eye (usually the same side as the dominant hand). The dominant eye, when both eyes are open, will fix the object when you point to it. If you point to the object now, you might see the ghostly image of the finger from your non-dominant eye.

Anchored

Touch all 5 fingertips on a table top. Bend your middle finger in and touch the knuckle to the table top. Lift your thumb Lift your index finger Lift your pinkie. Lift your ring finger.

Explanation: You move your fingers with tendons (which are attached to muscles in your palm and lower arm). The tendons in your fingers are independent except for the tendons in your middle finger and ring finger. These are connected, so when your middle finger is down, so is your ring finger.

Balance and Gravity

Stand with your back against the wall. Touch your head and heels to the wall. Without bending your knees or moving your feet from the wall, touch your toes. Take a step away from the wall. Without bending your knees and moving your feet, touch your toes. Repeat as needed to figure out why you can’t touch your toes when your heels touch the

wall, but you can when your heels are not touching the wall. Explanation:

Our center of gravity is around our hips. In order to bend forward, the center of gravity shifts, and to compensate for the top part of your torso pulling you forward, your hips move backwards.

Can You? Touch your nose with your tongue? Touch your elbow to your nose? Lift one eyebrow? Wiggle your ears? Twitch your nose? Twist your tongue to the right, and then twist your tongue to the left? Curl your tongue?

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Hold your hand up and open your fingers between your middle and ring finger (as in the Vulcan blessing, “Live long and prosper.”)?

Move one eye move while the other is stationary? Explanation:

Only people with long tongues can touch their nose with their tongue. The average human tongue length is just too short.

Unless you have an unusually short upper arm (humerus bone), your humerus is too long.

Humans don’t often use facial muscles in isolation, but in symmetry. It is possible to learn, but it will probably take practice. So, you can learn to lift just one eyebrow and wiggle your ears, but it takes practice. Wiggling ears and twitching noses also are helped by genetics. Those muscles are small, and not only does it take practice, but help from your ancestors!

If you can tongue twist, you are helped by genetics but if you can’t you can learn by practicing. If you can’t curl your tongue, you will never be able to do that. It is strictly genetic!

Everyone can move their eyes independently, but there is a trick to it. Without moving your head, look to the right. Now move your right eye to be cross-eyed (you are moving your right eye independently). Now move your left eye from cross-eyed to the left (you are moving your left eye independently).

Floating Appendages Stand sideways with your right side towards a wall, your right arm pressed against the

wall, and your feet about 6 inches from the wall. Keep your right arms straight, and your right hand down. For the count of 60 seconds, push your right arm against the wall as hard as you can. At the end of 60 seconds, relax your right arm completely and step away from the wall. Why does your arm rise up?

Explanation For a muscle to contract, a nerve cell signals a muscle cell to release calcium ions (an ion is an atom missing an electron) from the sarcoplasmic reticulum (isn’t that the greatest two words you have heard today!). For the muscle to stop contracting, the calcium ions need to be reabsorbed by the sarcoplasmic reticulum. When you push against the wall, the muscle can’t contract, but the muscle cell is receiving the signal to contract, and the calcium ions are flooding the cell. When you step away from the wall the calcium ions can make the muscle contract, and it takes a little time for the sarcoplasmic reticulum to reabsorb all those ions.

Creaking Fingers

Point with your index and middle fingers with your non-dominant hand. With your dominant hand (your writing hand) grab your fingers and squeeze. Continue squeezing for 60 seconds. At the end of 60 seconds, stop squeezing, but don’t let go of your fingers. Wiggle your index and middle fingers from your fist without opening your fist more than

you need to open it.

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With your fist fingers still curled, relax your hand and gently stroke your lower arm (palm side up) to help your muscles relax.

SLOWLY and GENTLY open the fingers of your fist. Do they get stuck?

Explanation: Your fingers are controlled by muscles in your lower arm and attached by tendons to the bones in your fingers. Muscles work in tandem, one muscle contracts, while the other relaxes. The tendons are attached from the muscles to the bones. When you make a fist, the muscle on the underside of your lower arm contract and pull the tendons, which curl your fingers into a fist. The muscles on the upper side of your arm relax, and allow those tendons to stretch to allow the fingers to curl in the opposite direction. Squeezing your fist for an extended length of time continues to stretch the tendons on the top of your hand. When you relax your hand, you are relaxing the contracting muscles on the underside of your arm, but the upper tendons are still stretched. As you SLOWLY and GENTLY open your fist, and the upper muscles of your lower arm contract, they pull on those stretched tendons, which in turn are shortening, but not smoothly. That is what you feel as you slowly open your hand.

Mismatched You need a partner. One partner hold arms out in front with the right palm facing the right and the left palm

facing the left. Cross your wrists (now the palms should be facing towards each other). Lace fingers together. Rotate your laced fingered hand down and towards yourself, until your knuckles are

rotated up and out as far as they can go. Your partner, without touching you anywhere, point to one of your fingers. Try to wiggle just that finger. Switch roles.

Explanation: Your right hand is now on your left side, and your left hand is on your right side. Your brain thinks that your right hand is still on your right side. If your partner points to a finger on your left, that is now your right hand, but your brain thinks it is still the left, and moves the wrong finger.

Directions for pencil and paper only: Touch and Go

You will need a partner. One partner turns with his/her back to the other partner. The other partner holds the pencil with the eraser up between half to one full arm’s length

to the first partner. The first partner covers one eye with one hand (not peeking!), and spins around. The first partner (keeping the hand over the eye) touches the top of the eraser with his/her

fingertip.

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Switch jobs, and the second partner tries to touch the eraser with just the tip of his/her finger.

Try this three times each. Now try it using both eyes.

Explanation: Our vision is binocular. Because our eyes are approximately 3-4 inches apart, the left eye sees everything at a slightly different angle than the right eye. about 3 inches away from what the right eye, our brain is able to accurately calculate distance.

Eye Spy Divide participants into teams (the number of teams depends on the number of

participants. Write the words "red," "orange," "yellow," "green," "blue," “purple,” “white,” and

“black” on separate pieces of paper. Have one member of each team pick a paper. The color picked will be the name of the

team. When you say "Go," the teams will have 5 minutes to look around the room for objects

that have their team's color. Teams must make a list of all the objects they find. After the 5 minute search period, the teams come back together and the lists of objects

are read. Each team gets one point for each object found. After the lists are read, each team will get 2 minutes to search the room for colored

objects that the other teams did NOT find. For example, if the red team did not find a red apple, another team that DID find the red apple will get one point.

The team with the most total points after both searches is the winner. Blind Spot

Take a piece of paper and the pencil, and fold the paper in half. On the left side of the paper, make a dot. On the right side of the paper, make an X about 3 or 4 inches from the dot. Hold the paper up with your right hand. Cover your left eye with your left hand. Look at the dot, and slowly move the paper forward and backward until the X disappears.

Explanation: The retina in our eye is the part of the eye that gathers light and sends it to our brain. The retina is composed of different cells, called rods and cones. The cones see colors, and the rods see in black and white in dim light. Each cell needs to connect to the brain that part of the cell (called the axon) is like a long thread that carries the signal to the brain. Each cell has an axon, and all the axons leave the eye at the same spot. Where they leave the eye, there are no receptors for light, so it is a true blind spot in the eye, located on the outside of our vision, and a little down from the main line of site. We don’t notice it because our brain fills in the hole.

Night Colors Origami paper (the kind that is white on the back on color on the front)

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Before the demonstration, divide the colors separating the lighter colors from the darker colors. Group 3 similar shades but different colors together using 21 sheets. The three colors do not have to be 7 each. In fact, it works better if they are not evenly distributed. For example, group 6 dark blue, 9 dark purple, and 6 black together.

Divide the participants into partners. Instruct the group to not touch anything until you direct them to turn over the paper. Distribute 1 packet of origami paper, face down (so the white side is up). Turn out the lights. Direct the participants to turn over the origami paper and divide it into similar colors. Turn on the lights, and count the number incorrect. Everyone turns stacks the origami paper and turn it back over to the white side. Everyone moves their paper to the right, and receives the paper from the left. Turn out the lights and give everyone 30 seconds to allow their eyes to become adjusted

to the dark. Direct the participants to turn over the origami paper and divide it into similar colors. Turn on the lights, and count the number incorrect. Everyone turns stacks the origami paper and turn it back over to the white side. Which time did they do better? Was it because they waiting the 2nd time, or because of a

learning curve? Explanation:

The photoreceptors in our eyes (the cells that collect light for our brain to see) are either cones (see in color) or rods (see in black and white in low levels of light). In low levels of light, our rods work (and can’t see in color). In bright light, our cones work, and swamp the images being collected by our rods. It is difficult to sort colors that are similar shades in the dark because we are using our rods. The second trial, we did better. Our eyes can let in more light when it is dark, and reduce light when it is bright. Our iris is the color part of our eye, and it is a sphincter muscle that acts like a drawstring bag. It takes a little time to adjust, opening up larger in dim light, and becoming smaller in bright light.