Northern Science

Chapter 7

 

EXPERIMENTS

Experiments are patterns we follow when we are trying to find the causes and reasons of different events.

The answers we find tell us Experimentswhat to increase to get better results.

The answers also tell us what to decrease to be more efficient and effective.

A good pattern to follow in experimenting is:

  • Identify the problem.
  • Identify the variables. (We learned how to do this in the last chapter)
  • Hold all variables constant.
  • Adjust one variable.
  • Observe the results.
  • Draw a conclusion from the results.
  • If necessary, repeat the experiment, adjusting other variables to see which is the most influential.

    Experiments

Experiments

My second year of teaching, I was in a very small village. When I arrived there, the students tried to win my favor. One of the boys, a first grader, said to me, "Me and Joe put feathers in our pockets and jumped off the bank, but we didn't fly." I struggled to keep from letting my smile show. Some time later, I thought about that experience, and felt very embarrassed. The two boys had done a great science experiment, and I had inwardly laughed at them.

  • They knew that flying was possible. They saw birds do it.
  • They knew that birds have feathers and we don't.

They finished their experiment still puzzled. They found out what did not cause flying. Feathers alone will not make you fly. They were certain of that.

What was good about their experiment?

  • They were curious.
  • They had an idea they wanted to test.
  • They had the boldness to test their idea.

Why didn't they come to a clear understanding?

They discovered that feathers in pockets do not cause flying. They didn't discover what does cause flying. They needed to take it further.

Experiments
Experiments

Example: Consider this simple experiment:

1) Mary wanted to find out if her family preferred chocolate chip or oatmeal cookies.

2) She identified all the variables.

  • size of cookies
  • number of cookies
  • location of cookies on table or shelf
  • containers
  • access to all family members
  • type of cookie

3) She held all of the variables but one constant.

Cookies were

  • the same size
  • the same quantity
  • the same time
  • in the same place on the counter, and
  • in identical containers.
  • available to the whole family.

4) She adjusted one variable, the type of cookie: chocolate chip and oatmeal.

5) It didn't take long to discover by counting that chocolate chip was preferred over oatmeal, three to one.

The next Christmas, everyone received a box of cookies from Mary containing twelve chocolate chip cookies and four oatmeal cookies.

What mistakes could she have made in the experiment?

However, she did it right. She held all the variables constant but one.

This was a good experiment! Mary could take this to a science fair.

Again, in a good experiment we:

  • Identify the problem.
  • Identify all the variables.
  • Hold all the variables still (constant),
  • Adjust one variable and observe.
  • Draw a conclusion from the results.
  • Repeat the experiment adjusting other variables if necessary to clarify the conclusion.

Experiments

EXPERIMENTS YOU CAN PERFORM

Wes is a good cross country skier. He isn't sure what kind of wax will perform the best under a given snow condition. Could he wax one ski one way and the other ski the other, and test it this way? What are the variables he would be holding constant by doing it this way? Can you think of a better way to find the best wax?

Wes later wanted to see if waxless skis were better for going up hills. How could he test this?

Experiments

Hank is a dedicated trapper. He knew that in some parts of the country marten prefer pole sets. In other parts of the country, they prefer cubby sets. He decided to have several test sites. He put a cubby set and a pole set side by side. Is this a good experiment if he uses the same bait and keeps good records?

How could Hank test different kinds of baits?

Nan's mom told her that damp socks cause much greater heat loss than dry ones.

Experiments
Experiments

Experiments

She:

  • got two identical thermometers.
  • dampened the liner of her left shoe pack, and put it back into the shoe pack.
  • put one thermometer in the dry right shoe pack and one in the wet left one.
  • covered each pack with identical pieces of thick cloth so they would not lose heat out of the top.
  • brought both shoe packs outside when it was -30°.
  • Twenty minutes later, she went to check the temperature inside each shoe pack.

What do you think she discovered? What would have happened if she went at different time intervals?

With that experiment done, she again dampened the liner of her left shoe pack and dried the liner of the right one. She put them on and went outside to play. What do you think she discovered?

After this, Nan wanted to test whether cotton or wool is a warmer material for winter weather. How could she duplicate the above experiment to test the materials?

Antone couldn't afford the expensive bunny boots that other people were wearing. He knew that his own sweat was condensing in the liner, freezing it to the outside of the shoe pack. He knew that Bunny boots have a vapor barrier that keep the moisture of the person's feet from the felt liner sealed in the boot. He tried an experiment. He put one shoepack on as he normally did. He put a sock on his other foot and wrapped that foot with a plastic shopping bag. He went outside. What do you think he discovered?

John often heard from the old timers that eating snow when you are out walking will make you very tired. They always warned him not to do it. Could John safely test this? Is there a science fact that would help him understand the truth in the old timers' statement?

Experiments

How important is the temperature of cooking oil? Make donuts of the same batter in the same shape and size. Cook them separately in oil of different temperatures. Leave them in the hot oil for exactly the same amount of time. What is your conclusion?

Do the above experiment keeping the oil the same temperature. Hold all variables constant except that some donuts will have holes and others do not.

What is your conclusion? Why do donuts have holes? What can you say about angel food cakes? How does that relate to the head of a chainsaw?

Experiments

Fred cut his hand. One day he put alcohol on it. The next day he tried a leading ointment. He said it seemed to heal better with the ointment. Was this a good experiment? How might a good experiment be done?

For all of the following, determine all the variables. Identify which ones are being adjusted.

Test different kinds of paper as freezer wrap for meat. Wrap identical pieces of meat with different types of wrap. Check after one month. Which one protects the meat from "freezer burn" (drying)? Try different methods of wrapping.

Once you have found the best wrapping paper, do the experiment over the winter, checking a different package of meat each month.

Cut fish three or four different styles. Hang the fish side by side. Which style produces the best tasting fish for eating during the winter?

 

Radios have built in limited reception so people in cities will not have too many stations covering over each other. In the north, this isn't a problem. Our problem is picking up remote stations.

Make a coil Experimentsof insulated wire as illustrated here, to greatly increase the number of stations received. To do this, hook one end of the wire to a good ground and the other end to the antenna. Do not connect, just place the coil behind the radio. Move it around until you get the best reception. This greatly magnifies the signal.

Experiment with the:

  • size of coil three inches to eight inches and
  • the number of turns of wire in the coil five to thirty turns.

What is the best combination of coil size and number of wraps in your location?

Experiments

Cut meat into different size pieces, equal amounts of each different size. Cook (either boil or fry) for the same amount of time. What can you say about the relationship of cooking time and the size of the pieces.

Experiments

16 oz.
8 oz.

Sell juice at a basketball game. Use two different size cups, but let the price per ounce be the same. Example:

  • 8 oz. = .40
  • 16 oz. = .80

Use the same juice.

Which do people prefer?

Once you have determined this, see if there is some way that you could have attractive cups and unattractive cups of the same size, selling for the same price. Does packaging change people's choices?

Let everyone in the class take a picture of the same object. The variables held constant are: Camera, film, object. The variables the students control are:

  • angle
  • distance
  • background contrast
  • other props included to enhance the photo.

Experiments

Set rabbit snares experimenting with:

  • size of opening
  • height of snare from trail
  • with or without a fence

Cut a block of wood with a dull chainsaw. Time the cut. Sharpen the saw and cut the same block, timing Experimentsthe cut again. How much difference is there? Are there variables here that you must be careful to control?

 

Cut identical blocks with two saws that are both dull, but one is a bigger saw and the other a smaller one. Time the cuts.

Sharpen both saws. Cut the same blocks again. Which saw is affected most by a dull chain?

Experiments

One team plays basketball in socks against a team that has tennis shoes. At halftime, switch roles, socks and shoes. Does traction (friction) make much difference in the score? How much?

Experiments

Experiments

Experiment with TV or radio antennas. Is reception better:

  • with the antenna parallel or perpendicular to the transmitting station?
  • during the day or night?

Problem: How will you measure the strength of the signal?

Can Experimentsyou shoot a rifle better standing, kneeling, lying down, or resting the rifle against a tree? Experiment with supervision.

 

What dExperimentso old timers tell you about breathing when shooting?

What is different about shooting from a boat in waves?

Wash one side of your head with one kind of shampoo, and the other side with another. (Or, don't use any soap on the other side at all). Can you tell the difference? Can others notice the difference?

If TV commercials have integrity, they are excellent experiments, as all variables are held constant except the product.

Test hair conditioner in the same way.

Experiments

Use one kind of acne medicine on one side of your face and a different brand on the other side. Which works better? What variables are being held constant? Read the contents of the "different" medications. Are the contents different, the concentrations, or just the name on the box?

Experiments

Are mittens or gloves warmer? How could you test this without thermometers?

Experiments

Put a trail snowshoe on one foot and a smaller bear paw on the other. Walk on a hard-packed trail.

Go out in the woods or tundra and break trail. What do you observe? Try both types of snowshoes in powder snow.

Experiments

Try one kind of popcorn in both the microwave and in a pot. Try microwave popcorn in the microwave and in a pot. What is the difference in results? Why do you think they are different? Which is more efficient?

ExperimentsExperiments

Make two campfires with identical setups except one fire is made with dry wood, and the other with green wood. What conclusions do you come to?

Experiments

Once the above drywood fire is burning, add two blocks of the same size, one dry and the other green. Which burns hotter? Which burns longer?

Does wood split easier in warm or cold weather? Cut blocks of equal lengths from a tree that looks difficult to split. In order to get two approximately equal piles of blocks, put the first block in the first pile. the second one in the second pile, third one in the first pile and continue to alternate until the whole tree is in two piles of about equal size.

Split one pile in warm weather. Record the time. Split the second pile in very cold weather. Record how long it takes. There are variables you will not be able to control, so this will be a crude experiment. The same person should use the same axe or maul.

Experiments

In the summer, put equal amounts of different brands of bug dope on opposite hands. Is there a difference? Afterwards, look at the ingredients and concentrations of both on the containers. Does this help you understand your results?

Experiments

On a very cold day, scuff your feet on a rug (nylon socks work best). Hold a key in your hand. Slowly approach a doorknob. At what distance will it spark from the key to the doorknob? Have two people hold hands and repeat the above experiment with the same key, same rug, same day and same doorknob. Record the length of the spark. Will the length of the spark increase if there are three, four, or five people in a row holding hands and scuffing feet?

Try the same experiment on a warm day. Be sure to have the same shoes or socks on. Record the spark length. Compare with the results of a cold day.

Ask someone who knows about computers what is done to keep "electric students" from zapping computers on cold dry days. Static electricity is a real danger for computers.

Experiments

Old
Faithful

New
lure

Test a new fishing lure. Be careful to keep the variables of location, depth, rate and method of retrieve etc. constant.

The first grade teacher was frustrated. She bought new crayons, but soon they were broken into small pieces. She devised an experiment to show the students what was happening. She bought a small box of crayons, and insisted that the students leave the paper on them. She bought another box of crayons, and peeled all the paper off them. What do you think they discovered? Try it.

Return to the section on Variables, Chapter 6.

  • Choose several of the situations there.
  • Describe how you would do an experiment in those situations.

Create: Think of situations of your own

  • questions you have wondered about
  • things you have wanted to prove to someone

Describe how you would experiment in those situations.

Looking ahead: The following experiments you will not be able to perform now, but might be faced with later. They are actual experiments that go on every day.

A TV company wants to see if a certain program would be viewed by more people if presented at a different time. How could they perform an experiment to test this?

A nationwide company wants to see if a new health insurance program will cut down on expenses.

A Native corporation wants to see if a summer program will help Native students succeed in college.

What other variables do you think influence success in college?

A school district Experimentsthinks a certain math program will help its students. How can they determine the effectiveness of the program?

Many years ago, a student did a simple experiment, "Why Your Tongue Sticks To the Flagpole". He used a piece of towel instead of a human tongue. He tried to stick the towel to:

  • glass
  • wood
  • plastic
  • steel
  • painted steel

He tried the above materials

  • when the materials were warm and cold
  • when the towel was either wet or dry
Experiments
Experiments

None of the materials stuck to the dry towel. Cold steel, painted or unpainted stuck to the wet towel.

From this, he drew a scientific conclusion, and placed very well in physics in the State science fair.

Can you think through and determine why a wet cloth (imitation tongue) sticks to cold metal, and none of the other materials?

It doesn't take a fantastic experiment to succeed in a science fair. It takes good science technique!

The real science adventure comes in doing something no one else has done. You will be amazed at what will attract attention of judges and people at a science fair. You will be amazed at what you can discover!

Experiments

CONCLUSION OF THIS BOOK

I have tried to teach a way of creative scientific thinking using Alaskan experiences. One, two, ten and even twenty years from now, you will surprise yourself and others with the ingenious and sensible solutions you develop for problems. Why? Because true Alaskans are never stuck.


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Write to me at:

AlanDick
Box162
McGrath, Alaska 99627
or fnad@aurora.alaska.edu