Monday, October 26, 2009

magic and science

magic

magic - trick with water and ice. How did I do that?
Trick with predicting a card. How did I do that?
Magic and science.
disappearing rabbit trick. Make something a kid has disappear. have them bark like a dog. Clap.
How does this work?
The trick thumb. Make a piece of paper vanish. Make a handkerchief appear.
kid lie on floor, hold arms over head, explain sensation. slowly lower kid's arms... tell me to stop when you think it will touch the floor.

Magic floating arm.
hydrophobic sand (can do with matches)... you can use baby powder to do this at hime.

3 cup monte with hydrophilic gel. Dissect a diaper.

Ninja popsicle sticks
====
Pick a number, any two digit number will do.

Add the two digits together and then subtract the total from the original number.

The result will always be a multiple of nine, so adding the digits of your answer will always result in the number nine.

38=11=27/3(first number)=9
96=15=81/8=9
This trick begins with a stacked deck! Separate the Aces and Kings from an ordinary poker deck. Place the 4 Aces on top of the other cards. Place the Kings on top of the Aces. Kings are now uppermost in the deck.

Find a volunteer and say something like: "You look like you can deal out a mean hand of cards! Please take this pack and deal out two piles, alternating cards."

Let them deal about half of the deck and then say: "You may stop anytime you wish". Take the undealt deck of cards and place them aside.

Say to your volunteer: "Now, please pick up one of those two piles and deal it into two smaller piles. Do the same with the other pile so that we will end up with 4 piles of cards."
At this point there will be a king on the top of every deck.

"Turn up the top of any pile. Oh....that's a king. Turn over another - another king! Coincidence. Yet another and another."

Once the volunteer has turned up all 4 kings discard them.

"Anyone here a poker player? What beats four kings? Why.....four ACES, right"

Make some magical passes of your hand over the four piles. Turn up the top card of each pile to reveal ACES

Static Electricity experiments

------------------ static electricity
* A balloon
* A clean head of hair
* Some tiny bits of torn up newspaper
* A sheet of aluminum foil about 1 foot long
* A wool sweater or sock
* A sheet of wax paper about 1 foot long
* A sheet of cellophane wrap about 1 foot long

Begin by blowing up the balloon and rubbing it on your head. What happens to your hair? Now lay the bits of paper out on a table in front of you. Bring the balloon near, but don't actually touch the paper. What happens?

Straw Exercise
Carefully tear one end of the paper and slide about one inch of the straw out of the paper. Rub the straw in and out of the paper for 5-10 seconds. Remove the paper and lay it on the table while hoding one end of the straw with your fingertips. Like a wand, lower the straw and hold it next to the paper, then raise the straw. What does the paper do?

Monday, September 28, 2009

taste

What's your favorite food?
* sweet
* sour
* salty
* bitter
Have counter count how many people like each.
  1. What are the four familiar tastes?
  2. What part of the body do we use to taste?
  3. Fifth flavor, "Umami." Cheese is an example of Umami.
  4. other things about food -- spicy, temperature, color, smell
Food you absolutly hate. What do you hate about it?
Have counter count qualities.

Going to be looking at taste. Will be using flavors on a cotton swab... don't mix and don't share.
Have four students demo how the taste test is done and how it's mapped. These become helpers at stations.

Can you taste the same thing in all areas of the tongue? Sweet, salty, sour, bitter. Bumps on tongue are taste buds and some get replaced every 24 hours! It was once thought that you could taste things only in one area. Is this true?
  1. Using your map, point to the places on your tongue where you would most likely taste a candy bar, potato chips, lemon juice, and a grapefruit peel.

bitter medicine -- people spit it out. If you put sugar in, is the bitter still there? Why would they tell us to put aspirin on the front of the tongue before swallowing it?
  1. What does the sense of taste teach you about the world we live in?
  2. How does taste help us select and enjoy food?
  3. What would happen to you without the sense of taste?

food coloring... paint your tongue front with blue food coloring. Place wax paper on tip of tongue. Count the number of unstained circles. the more of those you have the more fungiform tastebuds you have. This is why some people can't eat certain foods. Changes as you get older.

  1. Describe how the sense of taste and the sense of smell are related.
  2. What are some things that should not be tasted

Perfumes (which is which?) artificial flavor.

Smell-a-drink (coke and pepsi and diet coke) Which is which?
making gum drops?

Nose pinch and blindfolded smell of coke and pepsi and diet coke.

Forces

note: if class is small, divide into stations. For largest class, demonstrations. Bring tops.

Forces make stopped objects move and moving objects stop.
Have two volunteers jump. What made them come down? What made them go up (prompt for muscles)? Drop pencil. What made it fall?
Catapult... what made ball fly?
bouncing ball... what happens when it bounces? bounce clay. Now what do you think happens? Push in ball -- what happens to surface? Push in clay? How does ball act like muscles?

"Center of gravity"... what does that sound like? Place where things balance.
Put hat and string on someone's head. have them stand with legs apart. Where is center of gravity? Now stand on one leg. Where is it?
partner control -- have two kids. Ones sits on chair other puts thumb against first one's forehead. try to stand up. What happened with center of gravity?
have child prove they can bend to pick up pencil. Now, stand with toes to wall. Take 3 toe-heel steps back. pick up a pencil (they can't). What happened with center of gravity when you stick your hips way out?
Balance an improbable object with pencils (ball of clay on fork) How did that change center of gravity?

gyroscopes and tops -- precession causes motion in a circle. What makes a good top? How could I turn clay into top?
Gyroscope and bike wheel
coke bottle demo
Hot wheels roller coaster (but only use kids who have earned tokens)
Penny inside a balloon -- spinning things change their behavior. Throw balloon with spinning penny. What happened?

Tuesday, September 15, 2009

Dry Ice

Set up:

Make sure there's some space between kids, have them work in pairs.
Make sure there's warm water around (pitcher of water)
If you have a chance, put a spoon in the warm water while you take roll, etc.

Get attention of kids, give them rules, introduce yourself.

explain that we are going to play with something that most kids never get to touch. Drop dry ice (use spoon) in a glass of water, and sip it as it foams. Tell them that at the end they will get to try the same kind of drink for themselves. Pour some of the fog on a kid's head.

Mention that dry ice "sublimes" (turns into gas, not liquid) as it melts. Tell them you can demonstrate it (put warm spoon on a large chunk of dry ice. Press firmly. Let them hear it "sing."

Show how cold it is by putting water in teaspoon and count seconds until it freezes.

Give them water with a little bit of soap in it, let them play with the bubbles.

Make "fizzy drink"

Put the last of the dry ice in warm water, let them sit around fog, try to corral it. Talk about Halloween special effects.
Give teams a cup (or container) for water and straw

Sunday, September 13, 2009

Classic slime

What you need:
  • borax powder (20 Mule Team borax is what I use)
  • water
  • 4 ounces glue (that's 1/2 cup. Use Elmer's white glue or the blue school glue White makes opaque slime)
  • teaspoon
  • bowl
  • jar or measuring cup
  • food coloring (optional)
  • measuring cup

pour the glue into the jar. Add 1/2 cup of water (if you're feeling lazy, just empty the glue bottle and then fill it with water and mix in there. Add coloring.

Mix 1 tsp of borax into 1 cup of water. Slowly stir the glue-water into the borax-water mix (note... this makes a LOT of slime. You can make small amounts of it at a time, however)

For kids, pour it into a ziplock bag and have them knead the bag until the slime forms. The more that it's worked, the firmer it becomes. Store the slime in this bag in the refrigerator to prevent mold.


Slime Fun:
Do a "slime drop." (does it fall all at once or stretch? Whose falls slowest?)
What happens if you pull it apart really fast?
What happens when you pull it apart slowly?
Do "whose slime stretches farthest" race and "who has chunkiest slime".

Have them name their slime.

Growing cyrstal gardens

A fun project to do in class over the period of a week or so is grow crystals. Here's one of the "classic" recipes:
  • substrate.
  • 4 tbsp. bluing (found in grocery stores)
  • 4 tbsp. salt (any kind)
  • 1 tbsp. ammonia
  • 4 tbsp. water
  • food coloring
  • plastic bowl or plate
Place small pieces of porous rock (some lava rocks are ideal), pieces of broken clay flowerpot basins, pieces of brick, or even charcoal bricks (or paper towels, if nothing else is available) in a shallow plastic plate. Soak the substrate for 15 minutes, dot with food coloring, and pour the crystal mix over the substrate. Make sure there's enough of the mix to soak/float the substrate in.

Crystals will begin to grow in four hours and can continue growing for up to three days, depending on other conditions
. Add more solution to keep them growing for a bit longer.

Tuesday, August 04, 2009

Detective Scavenger Hunt

Only do this in an area where you can have good control over the kids (noise and damage -- and make sure they can't injure themselves. Warn them away from or block off areas where things could be damaged.)

If you don't have time to make up a scavenger hunt list before the kids show up, hide a few things around the room and divide the group into teams. Have each team make a list of things for the other teams to find. Pull all of them out of the room and give each team (or person, if the group is small enough) an additional item to hide. Add that to the list.

Swap lists.

Turn them loose.

This can also be done to good effect with outdoor activities (make a rubbing of a leaf shaped like an arrowhead, find a bird, find an oak tree, etc)

Tuesday, July 07, 2009

Using a rubric

Here's a nice page on using rubrics in teaching, something that can be added to a summer camp activity or any of the kits: http://www.learnnc.org/lp/pages/3735

In a nutshell, when doing something comparative, have the students list for you words that exemplify the quality of something (for example -- slime. You might pick "gooeyness" and "color" and "stickiness") and then judge a sample on a scale of 1 to 5. Everyone can pick a number; add them all together and divide by the number of people (to make it easy on yourself if you have an impatient class, divide the class and have one group judge on one attribute and another judge on a different attribute. YOU do the math, or hand someone a calculator and ask them to do it.)

Rubrics can be used as a starting point for a discussion in many different areas.

Monday, June 22, 2009

Potato/tomato/lemon/vinegar battery

There's a number of videos on this activity that you can find through Google. Unfortunately, given the nature of video, they often vanish mysteriously into the bit bucket. And you can't give them a 20-second "look over" to refresh your knowledge; usually you have to sit there through the whole production.

So here's about making batteries from unusual things.

* it takes some sort of acid in solution. You might be able to do it with unusual things like aspirin diluted in water because (according to internet sources... we all know how reliable those are...) UNbuffered aspirin can be used to temporarily "revitalize" a dead battery. I'll try it sometime. Meanwhile, other things you can make batteries from (in case you forgot to buy a potato for the demonstration) include vinegar, lemon juice, and cola.

* you need an electrode of copper and one of zinc. A nail (zinc coated) and copper wire (or a penny) work well for this. You could use silver instead of copper, but that's more expensive.

* make sure the "leads" are clean. A little scrub with an abrasive works.
* if you're not using a vegetable or fruit, get a small container for the liquid.
* the amounts of electricity produced are small.
* use them to power a small LED. Look for one (Fry's) that doesn't require a lot of voltage.

http://www.physics.gla.ac.uk/~kskeldon/PubSci/exhibits/E1/

http://hilaroad.com/camp/projects/lemon/calculator/calculator_battery.html

If you think you've got kids who may have seen potato/lemon/tomato batteries before, provide them with a little novelty. Using oranges or cola (or unbuffered aspirin if it works) will provide the "say WHAT?" factor that keeps them intrigued.

You will connect the battery components in series, not parallel, if you want to try and power a light:
http://www.sierranevadaairstreams.org/owners-guide/understanding/battery-config.html

http://www.zbattery.com/Connecting-Batteries-in-Series-or-Parallel

Saturday, May 16, 2009

Keeping them amused in the morning

Papercraft (you print out 10 pieces of paper, bring scissors, glue, let them have at it usually does 2 things -- they're interested in a build and are learning build skills and they're keeping quiet.

A few for you to look at:
robots:
http://members.chello.nl/m.egtberts2/pdf/retrobot.pdf

Color their own/make their own:
http://members.chello.nl/m.egtberts2/pdf/fs_blank.pdfhttp://thunderpanda.com/509/

Thunderpanda Troops:
http://thunderpanda.com/509/

Wednesday, May 13, 2009

News stories for teachers

There's a "Robot Hall of Fame" at the Carnegie Mellon Institute, and there's a list of new inductees. Some are fictional, some are real, all have had a very strong social impact:
http://www.robothalloffame.org/

An article on how people react to robots -- it's mainly in how you think of them:
http://www.newscientist.com/article/dn14666-robot-builders-seek-a-little-help-from-scifi.html