Chapter 5

FINDING FACTS

When I start to search out a matter, the first thing I do is find someone who knows more than I do. I ask questions, and hang around that person until I feel I have learned as much as I can. When I first came to Alaska, I spent hundreds of hours listening to the elders. I often heard the same story ten or fifteen times, but each time there was a new fact, a new insight, a new place name to store away in my memory.

Some people talk too much and share a lot of irrelevant information. That is the price of fact finding. Some people know so much more than we do, we walk away feeling like we am the most ignorant person in the world. When that happens, I let the facts simmer in my head for a while. I then go back for another dose of information. Other people know many things, but can't explain it well. It takes patience to learn from them.

There are other places to find facts, like libraries, book stores, the Internet etc. Usually we are not the first person to have the problem or ask the question. There is often a trail of information to follow. However, we are among the first to apply Western science to village situations. In that regard, we are on the cutting edge.

	TRADITIONAL FACT FINDING Traditionally, Native people have been intuitive scientists. In their exploration of the world, they have been aware of the subtle forces acting on men, animals, and the earth. Much knowledge has been acquired by a combination of thinking, observing, and listening. Many of the elders are leaving us now, so it is important that we not only gather from them the knowledge they have, but also learn the process by which they learned. Their process seems gentler, less intrusive than that of western science. The basic assumptions are different. Man is seen as part of a whole rather than a dominant force. Their science has a firm connection to values. This isn't to minimize the wonderful influences of Western science, but acknowledges that there are other ways of knowing that have validity.
	PHYSICAL LAWS AND PRINCIPLES There are certain physical laws and principles that work all the time. They represent facts that you can count on. They apply in many different situations. They are not laws like, "If you drive a four wheeler on the roads without a license and get caught, you will get in trouble." That kind of law says, "If you get caught, something bad will happen." Physical laws and principles are different. They happen every time, all the time. They are general rules of nature that have come from lots of observation of the natural world. Both Native people and Western scientists have spent countless hours observing how things work. If you believe in gravity, it works. If you don't believe in gravity, it still works. By the time you went to school, you had that figured out. When I was about five years old, I really wanted to fly. I thought "If I believe enough, I can fly." After days of thinking about this, I climbed up on the swing set my dad made for me. (I think I had a towel around my neck to flap in the wind.) I very carefully put all fear and doubt out of my mind. I knew that was important. I thought about flying with all my might, and jumped off. That was one of my first science experiments. I discovered (That's what scientists dothey discover) that believing doesn't change the law of gravity at all. My great faith in flying didn't slow my fall in the slightest. I remained on the ground for a long time. My body hurt, but my understanding was damaged even more. It took me a long time to sort it all out. We cannot say that gravity is bad. It causes planes to crash, but it also keeps the blankets on us during the night so we won't be cold. Gravity causes rain to fall on us when we want sunshine, but you couldn't play volleyball without it. We learn to use the positive effects of gravity, and avoid the negative effects. Gravity is a law here on earth and everywhere else in the universe. I like physical science laws because they treat everyone fairly. Russians and Americans, Natives and Orientals, the rich and the poor are all treated without favoritism by science laws. The only people who are hurt by them are people who ignore them. If you believe in them, they work. If you don't believe in them, they still work. Great athletes aren't exceptions to the physical science laws. In a way they are scientists, because they experiment and learn how to work with them. One of the purposes of this book is to help you become aware so science laws can work for you instead of against you. There are many science laws and principles, but there are a few basic ones that we deal with every day. Have you ever heard of someone who ran an outboard motor, snowmachine, or chainsaw without oil in the gas? What happened? If you believe in friction, it works. If you don't believe in it, it still works. An old man from an upriver village was traveling by boat during a heavy rain. He thought he could make it home before he ran out of gas, but his engine quit. He quickly poured gas into the tank. He forgot to put oil in the gas. Before he arrived home, his engine was totally ruined. Friction between the moving parts caused great damage, and cost him over $2,000. Is friction bad? Not necessarily. You could not light a match without the heat from friction. We could not live without it. You can: Learn about physical science laws and principles and use them, or Choose not to learn about them, and find out how powerful and effective they are against you. Those are the choices before you. QUESTIONS: 1) What are some things to do when you first search out a matter? 2) What are some of the differences between the traditional Native ways of science and the modern ways of science? 3) Name one difference between science laws and the laws of our country.
	NEWTON'S THREE LAWS Long ago, a man by the name of Isaac Newton described three physical laws. His description has helped scientists and students for centuries. The first law is the law of inertia, which we will discuss in this book. The second law says that the force on an object is equal to it's mass times the rate of acceleration. What that means is this: If an object has greater mass, it takes more force to move it. It also says that the faster you try to accelerate the object, the more force it will take. Fast acceleration, more force. Slow acceleration, less force. A loaded fourwheeler takes more force to move than one with no load. It takes more force to accelerate a fourwheeler quickly than it does to accelerate slowly. The third law says that for every action there is an equal and opposite reaction. You shoot a shotgun. The lead goes out of the barrel, but there is an opposite force against your shoulder. We say "the shotgun kicks." Many forces operate at the same time. As we look at the reasons behind our science questions, we must realize that seldom is only one force working. There are often several. Some work together, and others oppose.. A boat floats in the river. There are many forces working on it. Gravity is pulling it towards the center of the earth. The buoyant force of the water is lifting it up. The prop is pushing it forward. The water in front of the boat is holding it back. Wind is blowing it in another direction. Quite often many forces are working at the same time.
	INERTIA The law of inertia says: Something at rest tends to stay at rest until a force acts on it. Something in motion tends to stay in motion until a force acts on it. A snowball stays on the porch railing all day long until someone picks it up and throws it. That same snowball will stay in motion until it is acted upon by a target of some sort, like a sign or a tree. SPLAT. Then it will stop immediately because the tree exerted a force on it.
The bucket stops and the contents keep going by the law of inertia	Before we had indoor plumbing, we had to empty the slop bucket. I used the law of inertia to empty it. I set the bucket and contents in motion. I quickly pulled the bucket back, and the contents, by the law of inertia, kept going. I once played basketball in a gym that had a stairwell behind and beneath the backboard. The school had to station a large policeman to catch players who were carried by the law of inertia into the stairwell after each layup. The law of inertia acts on us all the time. You travel on a snowmachine and hit a tree. You to stay in motion even though the machine has stopped. (Ouch!)
	You are in an airplane when it's rough. The plane hits a bump and goes up, then hits a downdraft and drops. Inertia has your stomach going up when you are going down. It feels very unpleasant when your body and your stomach aren't traveling in the same direction. What do you feel in an elevator? I had a dog team for years. I would often think about ways to go faster, or farther. I thought of the things that the dogs are working against: Friction. Smooth plastic runners help tremendously. Hills. I would often get off the sled and help push the sled up hills against the force of gravity. Bumps. Bumps and rough terrain slow the sled below the normal pace of the dogs. The dogs have to exert more force to get the sled back to the right speed. Keeping the sled at a constant speed, so the dogs are not continually working to overcome inertia is a challenge for the musher.
	The musher must push or lean to make the sled go smoothly. Many mushers put shock cord (elastic) on the bridle of the sled to cut down on the sharp forces against the dogs when the sled slows abruptly. How do snowmachines lessen the effect of a rough trail?
	What is happening when you get catsup out of the bottle like this?
	Did you ever have something stuck to your hand or finger and shake it to free yourself? Is this using the law of inertia? Put glue on a piece of tissue. Stick it to your finger. What is your natural reaction to get it off? What principle are you using?
	Explain why dogs shake after coming out of the water. What is happening?
	My dad told me why pistons in engines are made of aluminum. Pistons go up and down thousands of times a minute. If the pistons were made of a heavier metal like steel, changing direction would use more energy. It would reduce the engine's power and put a great strain on the crankshaft. Light pistons have much less inertia than heavy ones traveling at the same speed.
	Would you rather split large blocks of wood with a boy's axe or an eight pound maul? Explain this in terms of inertia. Would you rather split kindling with a boy's axe or an eight pound maul. Explain this in terms of inertia. Why do we use a big chopping block? Would you use heavier or lighter bullets when hunting in the brush? Why?
	Martha was going to build a dog house. In the shop she found many different hammers. She found a 16oz. and a 20 oz. hammer. Which one should she choose to drive big nails into 2 x 4's? Which one should she use to nail a picture frame? Harry wants to hunt geese but he is afraid of the twelve gauge shotgun will kick too much. What advise could you give him before he buys one? Do you think a heavier gun might help? What happens when you are riding a bike, and apply the front brakes without touching the rear brakes? Why does this happen? What do you think would happen if a car's rear brakes failed and the front brakes were the only ones working? Draw this.
	The head kept coming off Helen's axe. She didn't know what to do. She tried to pound the head back on with a hammer, but it didn't work. Can you suggest a better way? Frank wants to build a displacement boat with a rounded front to have more room inside the boat. He is going to haul big loads. His dad tells him to make the front more pointed with gradual turns to cut the water gradually. Which do you think is right?
	TOOLS/EQUIPMENT WE USE TO INFLUENCE INERTIA When something is at rest, we push, pull, or use engines and motors as outside forces to get it in motion. When something is in motion, we use brakes to slow it down or stop. Describe how the brakes work on: a four wheeler. a car or truck an airplane landing a dog sled on clear ice and powder snow. Friction is used to influence the inertia of something moving. What kind of "brakes" do you use to control your motion in sports? Compare three different brands.
	INERTIA ON CURVES AND CORNERS Have you ever, on a rainy day, ridden a bicycle that had no back fender? What happened? When you go slow, it's okay, but when you go fast, the water flies off the rear tire and paints a muddy stripe down your back. Why does this happen? The law of inertia says, "A body in motion tends to stay in motion until acted upon by some other force." We can add a little to that and say, "A body in motion tends to stay in motion in a straight line until acted upon by some other force." The water and mud on your tire, by the law of inertia, stay in motion in a straight line until acted upon by another force (your back).
	The first three wheel ATV our family owned was a little Honda 110. It was fun for the whole family to drive. It was not fun for the whole family to maintain. No one wanted to tighten the chain when it got loose. They drove it with a loose chain. One day, one of our children walked into the house and said, "The three wheeler stopped." That really meant, "Dad, you have a problem." I went out to get it going. It had gas. The switch was on. It started, but made funny noises. I stopped it, and checked the oil. It was empty! I remembered checking the oil two days earlier. How could it be empty? I pushed it home. The next day, I discovered the problem. The loose chain, by inertia, had flown forward from the front sprocket, and had gouged a hole in the crankcase. The oil ran on the ground as fast as we poured it in. That was an expensive lesson in inertia. Remember, science laws work whether you believe in them or understand them or not.
	Water, as it flows around the bends of a river, follows the law of inertia, tending to go straight rather than change direction. If there is a bend in the river, where is the current the fastest? Where is the river the deepest? Many towns in the North are threatened as the rivers, influenced by inertia, take land and houses by erosion. What slows erosion?
	Get a chainsaw. Remove the sprocket cover, the bar and chain. Safely start the saw and watch the clutch work. What laws are working to cause it to expand and force the drum to turn? What would happen if the spring holding the shoes became weak? What would happen if you replaced it with one too strong? Erin notices that the bar oil on his chainsaw sprays off the bottom of the roller nose on his bar in cold weather, and off the top in warm weather. Why is this? Should he be concerned? Warm weather Cold weather
	When a boat prop is damaged by hitting the bottom, it causes the motor to shake. Why is this happening? What damage do you think it can do? Have you seen or used an "Eskimo yo-yo"? What keeps the two balls extended at the end of the string? Brian was riding the sled behind the snowmachine. His brother Einer was driving. They were cold, so Einer drove fast. As they came into the village, they went around a corner. The snowmachine turned ok, but the sled swept sideways, almost beside the snowmachine. The sled hit a chunk of ice, and flipped over. Explain what happened using the concept of inertia.
	QUESTIONS 1) What are Newton's three laws? State them. Give an example of each. 2) Give an example of a situation where more than one force is working at a time. 3) Give three examples of the law of inertia working. One should be from your own experience and not from this book. 4) Why does a dog shake when coming out of the water? How does he use the law of inertia? 5) Describe one method of putting an axe head back on. 6) Draw one tool we use to overcome inertia. 7) Why does water splatter your back when you ride a bike in the rain (if you have no rear fender.) 8) Describe or draw how a chainsaw clutch works. 9) Give two examples of inertia working for or against you in your own life.
	FRICTION Friction is the resistance to motion when surfaces are in contact. Static friction is when the surfaces are not moving, and kinetic friction is when they are moving in contact with each other. Static friction is usually much greater than moving friction. It is hard to get a sled moving, but once it slides it pulls easily. Rub your hands together. Do the same thing with soap on your hands. Which would has more resistance? Soap lessens friction. Almost every movement on earth has friction.
	Sometimes we try to increase friction. Years ago we occasionally crossed icy windswept mountains. We would often put socks or burlap sacks over our shoes to avoid slipping on the windblown ice and snow. We tried to increase friction to keep from sliding off the mountain.
	We used to put wood stove ashes on the steps and walkways of the elders homes so they wouldn't slip on the ice and snow. Stove ashes greatly increase friction. Sometimes we try to decrease friction. Before plastic runners on dog sleds, we spent much time changing from steel runners in warm weather to wooden runners in cold weather. We were trying to decrease the dogs' work against friction. When the weather was below freezing, most mushers iced wooden runners in the morning with a wet rag. The iced runners had low friction. However, if the weather warmed, the ice melted and the sled was almost immovable on the roough wooden runners. Steel runners were very slippery when temperatures were above freezing, but they frosted, and were like sandpaper when the thermometer fell below 25°.
	Some materials increase friction. Rubber, rock and wood all have high friction surfaces. Some materials decrease friction. Oil, grease, plastic and ice all have low friction surfaces. In general, the rougher a surface, the more friction it has. the smoother a surface, the less friction it has.
	INCREASING FRICTION Some objects are made to increase friction. Tires, tennis shoes, brakes of all kinds (car, sled, and airplane), as well as gloves, snowshoes, and tool handles are all designed to increase friction to improve use. Get some of the above, look closely, and handle them. What do you conclude? We made a moose skin boat in the spring of the year. It was very hard to tie the wet moose skin when we lashed it together. The skin was too slippery. One of the old timers put a small bunch of grass on the end of the strip of moose skin and tied the knot around it. The grass increased friction and the knot held. Another time we were hanging fish on poles to dry. The poles weren't spruce, and the fish kept slipping. A little grass placed on top of the pole before the fish was hung increased friction and kept it from falling.
	DECREASING FRICTION Some objects are made to decrease friction. Wheel barrows, sled runners, wax coated bullets, underwear made of synthetic materials, and nylon starter cords are all made to decrease friction. A boat bottom should be painted and smooth or the owner will use lots of gasoline overcoming friction with the water. Some boat paints have compounds in them to keep water plants from attaching to the boat. When we lived on the Stony River, the current was very swift. We had no problem with this. When we lived on the Holitna River, the current was so slow we had lots of aquatic plants growing on the boat. We had to use treated paint to avoid plant growth that produces friction. You may have noticed that a boat will travel faster in choppy waves (1"to 5"). Air is trapped under the boat. Friction with air is far less than with water. Without oil and grease to reduce friction, no machinery could work for long. Iron against iron creates much resistance, heat and wear. Oil an old pair of scissors. Can you tell the difference before and after oiling?
	There are many kinds of oil. Some lubricate, some do not: crankcase oil for a car, two cycle oil for a snowmachine, bar oil for the chainsaw bar, diesel engine oil for an electric generator, thin lubricating oils for cold weather, thick lubricating oils for warmer weather, and even cooking oil to cook your hotcakes and seal oil and bear fat for lamps (not lubricants) Without oil, our civilization could not have developed. Most oils reduce friction of moving parts.
	A child came crying to her mother with a finger stuck in the mouth of a bottle. The mother poured liquid soap around the finger, and the child's finger slid out of the bottle with no harm or pain. An understanding of friction is very important to an intelligent world view. Both engineers and mothers need to understand it. How does friction effect the following: Airplanes? Swimmers? Bicycle bearings? Arnold lived in Fairbanks Alaska. He couldn't understand why the front wheel bearings wore out quickly on his car. The previous owner was from Alabama. Can you explain this to him?
	An unlubricated fishwheel creaks, groans and scares away fish. When we don't have grease for the bearing, we lubricate with salmon eggs that have considerable amounts of oil. Can you think of other lubricants? Name ten things that move. Identify the points where two surfaces are moving against each other. Don't forget friction with air. What is being done to increase or decrease friction at that point? Get a moose or caribou leg. Take it apart at the knee. Observe the fluid in the joint. Feel the fluid between your fingers. Will it reduce friction? Observe how smooth the cartilage is.
	You are on a mountainside. You are afraid to go down the mountain with your dog team. Your brake isn't good enough. What could you do? George doesn't have enough money to paint his boat. He thinks of putting it in the water without paint this year. What advise can you give him?
	Try a pair of waxless cross country skis. Explain how they have more friction when traveling in one direction than when traveling in the other. How is this same effect created on skis that use wax? Draw this in action: A ski gliding, and a ski kicking. label and explain. Some snowmachines have slide rail suspension and older ones have bogie wheels. Why is there a difference? Which is better for what conditions? Why did old timers use spruce poles to hang fish, and not birch or willow? QUESTIONS 1) What is friction? 2) Name five situations where you might want to reduce friction. 3) Name five situations where you might want to increase friction. 4) What is viscosity? 5) Give five examples of how old timers showed their understanding of friction.
	SURFACE AREA Surface area is the amount of surface that is exposed. You can hold a piece of paper in the air. It has a large surface area exposed to view. You can lay the paper on a desk. The back is now touching the desk. It has less surface area exposed to view. You can ball the paper up in a little ball, and it has even less surface area exposed. Understanding surface area helps us explain many useful science phenomina in village life. When you dry fish, you try to increase the surface area which can dry. When you sharpen a knife you try to reduce the surface area so the blade will penetrate the meat or fish.
	If you jumped out of an airplane without a parachute, you would fall fast and be dead on impact. With a parachute you are increasing the surface area in contact with the air. With a parachute, you bump into many more air molecules, slowing you to the point at which you can land safely.
	Why do chainsaws and most snowmachine engines have fins on the cylinders? Why do dogs curl up at night in the winter? If you want a snowmachine for breaking trail in soft snow, would you get one with a large or small track? Why? If you want a snowmachine for racing, would you get one with a small or large track? Cleated or uncleated? Penny has to cook supper in a hurry. The family expects to have fried moose meat. How can she cut the meat so it cooks faster?
	Why did old timers make shavings to start a fire in the morning? I used to fly from the Yukon river to the Kuskokwim during the winter. I noticed that both rivers could have clear weather, but it would be foggy in the Beaver Mts. between them. Why do you think this happens? Years ago when we traveled only by dog team, we sometimes had to cross thin ice. We spread our dogs out on a long towline. This did two things: it increased the surface area that our dog team occupied on the bad ice. Pounds per square foot were much less that way. We were less likely to fall through the ice. Second benefit: When we did fall through, there were usually several dogs far ahead of us on solid ice who could pull the rest of us out. However, a team spread out like that couldn't travel through timber without bumping trees and getting badly tangled. We had to shorten our towline after crossing bad ice.
	QUESTIONS 1) What is surface area? 2) Give two examples of reducing surface area. 3) Give two example of increasing surface area. 4) Why do you think mittens are warmer than gloves? 5) Why do you think we use snowshoes for walking on the snow? 6) Why do you think we sharpen a knife to a very thin edge? CONDENSATION Facts: 1) Water exists in three forms: solid, liquid, and gas. As a solid it is ice. As a liquid it is the water we pour and drink. As a gas or vapor it mixes with the air and will not remain in a container. (It is important to distinguish between a gas, which is an element or compound that cannot be held in an open container, such as air, and "gas," meaning gasoline. While the words are the same, the meanings are very different and cause for confusion.) 2) Warm air holds more moisture (water) than cold air. 3) Evaporation and condensation are opposites. Evaporation is when a liquid such as water becomes a gas. Condensation is when a gas becomes a liquid such as water.
	When we go outside in the winter we see our breath. We can't see it in the summer. Why? Single-pane windows frost when it is cold outside. What is happening? Where does the water come from? What do we do to prevent this? People who wear glasses see clearly outdoors when it is cold. As soon as they come inside, the glasses fog up. Why? What do people do to get the fog off the glasses. How does this help? Some people say they won't fog if you walk into the house backwards. Does this work? Do the above. If it is warm outside, put the glasses in a freezer. When people want to get dirt from their glasses while inside the house, how do they clean them?
	Why did old timers keep their guns outside during the winter? During fall time on the river or in the valleys, there is often fog in the morning. Why? Where does the fog (water) come from?
	Many northern homes burn to the ground because uninsulated stovepipes become rusted and thin at the point where the pipe emerges from the building. Why is this? What could you do to prevent this? During very cold weather, fog appears in the doorway when the door is opened. Where does the fog come from?
	Moxie was really cold in his sleeping bag. He tucked his head inside the bag. It warmed up a lot from the heat of his breath. At 4 a.m. he was colder than before. The outside temperature had not gone down since he went to bed. Why do you think this happened? Why do you think the windshield on a truck, car, or snowmachine frosts more heavily overnight than the rest of the vehicle?
	Look at the lid of a dutch oven. The steam condenses on the cooler lid, and the water drips back onto the food, causing the meal to be moist, and the juices of the different foods to mix. Without the drippers, the steam would condense on the top and run down the sides. The middle of the pot would be relatively dry. My son-in-law noticed that he always had trouble with his snowmachine after a warm spell. The engine would shoot and backfire for one or two days, and then it was okay again. He couldn't understand why. Finally, he heard some airplane pilots talking. They said they always keep their gas tanks full during warm weather. If a tank is half full of gas, it is half full of air.
	When the weather turns cold, the warm air inside the tank cools. The water that was in the warm air condenses in the tank forming frost. This is very dangerous in an airplane. My son-in-law remembered this. During the next warm spell, he kept his snowmachine tanks full. He had no water or ice problems when the weather turned cold. The frost had caused the "shooting" as the ice exploded into steam in the cylinder.
	I was in the Hawaiian Islands. I noticed that most of the islands had a dry side and a wet side. The warm damp air comes off the ocean. As it rises up the mountainside, it cools. The water condenses (rain). When the air goes down the back side, it warms up again, drawing moisture from the plants and soil. One island, Lanai, does not have a dry or a wet side. It is a low island, with no mountains or peaks.
	Why does Fairbanks have drier summers than Anchorage? Look at a contour map. I worked underground in Red Devil mine. I had an excellent raincoat, yet I was very wet at the end of every day. Why do you think this was so? Why do stovepipes connect like the pipe on the left rather than the one on the right?
	QUESTIONS 1) What is condensation? 2) Give five examples of how condensation has affected life in Alaska. VAPOR BARRIER We use a thin plastic vapor barrier in all Alaskan houses. If the vapor barrier is between the insulation and the home, warm damp air inside the home is never cooled off, and cannot condense. If the vapor barrier has a hole in it, warm air escapes through the hole, and somewhere in the wall or ceiling, it is cooled enough to condense. It then wets the insulation, making it inefficient. It also causes rotting inside the wall. An old timer lived in a log cabin with a sod roof. When rolls of plastic first came to the Alaska, he fixed his roof.
	In the summer he: removed the old sod put more grass on top of the roof, covered the dirt with moss and sod. covered this with more dirt, and covered the sod with heavy plastic. Winter came, and he was glad that his house was much warmer than before. One day the weather warmed. It started raining inside his house when it was sunny outside. It dripped everywhere. He wondered why. Can you explain this?
	In one of the schools in our district the gym roof leaked every time the weather warmed. Maintenance workers went all over the roof looking for holes in the steel. They found no possible leaks. Months later they discovered the problem. The roof was made of pre-fabricated panels. They were put together like the illustration on the left. When the contractors built the building, they did not put enough glue between the panels when they nailed them together. Warm air escaped between the panels, and frosted on the back side of the roofing steel. What they thought was snow and rain leaking through the roof was actually the condensation of people's breath dripping back on them. The moisture had never left the building.
	Bernie went from his village and stayed in a fancy hotel. He was amazed that there was something like a towel or blanket around the toilet bowl and toilet tank. He couldn't understand this at all. Can you explain it to him? Evaporation Evaporation is when a liquid becomes a gas (vapor). Evaporation is the opposite of condensation. There are times when we want evaporation to take place. We hang fish in the smokehouse. We hang meat to make dry meat. We hang clothes on the line.
When the white gas in a camp stove passes through the small pipe that goes from the tank to the burner it is heated by the flame of the burner. This causes the white gas to evaporate in the pipe. When the white gas comes out of the burner it burns much more thoroughly as a vapor than as a liquid. What do you think will happen if the generator is dirty where evaporation is supposed to occur?

	We want evaporation from fish or meat in a smokehouse. What do we do to increase evaporation? What will happen if considerable evaporation doesn't take place within a few weeks?
	We make sure that our smokehouse has lots of fresh air. There have to be vents and doors. If there is no ventilation to enhance evaporation, the fish will sour. Of course, too much ventilation carries the smoke away, and the blow flies get to the fish. There is a delicate balance between: enough fresh air and enough smoke to keep flies away. Your fish didn't dry well last year. This year is predicted to be more rainy. What will you change about the way you cut the fish?
	We hang clothes on a clothesline to increase evaporation. Look at the clotheslines in your town or village. What can you say about their location? What can you say about a clothes dryer regarding: temperature flow of air movement of the clothes. What similarities do you see between a clothes dryer and a good day for drying clothes outside on the line?
	AVOIDING EVAPORATION There are times when we do not want evaporation to take place. My wife wraps birch bark in a plastic bag while bringing it home so it will not dry out before she makes birch baskets. We put a cap on our gas tanks so the gasoline won't evaporate. We wrap meat before we put it in the freezer to prevent freezer burn (drying). When I don't want a paint brush to dry out by evaporation, I wrap it in plastic and put it in the freezer. It is still in good shape days later. I don't have to clean it as long as it is frozen. Any place there is a liquid, there is the possibility of evaporation.
	Look closely at freezer paper. How is it different from other paper? Wrap a piece of meat in freezer paper. Wrap another piece of meat in the paper from a paper bag. What difference do you predict? After three to four weeks, what difference do you see, if any? Which piece of meat would you rather eat? Why?
	Angela wondered why trees have bark. She peeled a portion of bark from several types of trees, and noted that the bark has very little strength. Can you help her understand? I have run many sawmills and have always wished that trees were square, as there is so much waste in the slabs cut from the sides. Why do you think trees are round?
	EVAPORATION OF WATER REQUIRES HEAT When any liquid evaporates (turns from a liquid to a gas) it requires heat to do so. When you step out of a warm shower, you become chilled until you dry off. Why? Where is the heat coming from to evaporate the water?. When we exercise, our body perspires. Why? Considering this, should we avoid sweating when exercising? Roger was in the mountains during the summer and was very hot from climbing. His partner said that he should pour water over his head to cool off. Roger said the water they had available was too warm to cool him. Was this correct thinking?
	The first time I built a log cabin I was in a rush to get done before winter. I built with green logs. I was surprised that the house was very cold for the first week or two. Can you explain this? One summer I accidentally twisted the valve on a propane bottle while I was hauling it to my house. Propane came out in a big fog. I reached through the stream of propane to turn the valve off, and almost froze my hand. Why? Before the river breaks up, the weather seems warm. After the river breaks, the air seems cold, though the days are longer and the sun seems stronger. Why is it colder?
	Margaret bought cordwood. She noticed that the green wood didn't give as much heat as the dry wood. Explain this to her. Last week I was in the village store. On top of the vegetables were burlap sacks that had been soaked in water. Why did the owner do this? You are going up the river in a boat. It rains very hard and your coat gets wet. Wet insulation is poor insulation. We know that. What else is cooling you off? What can you do to reduce this effect?
	You are camping out. The fire is burning well before you go to bed. You would like a little fire still burning in the morning. Would you put blocks of green wood or dry wood to accomplish this?. CARBURETOR HEAT On approach for landing in a small plane, you often see the pilot pull out the knob labeled "carb heat". Pilots do this even if the outside temperature is well above freezing. A carburetor works like a refrigerator. When the liquid gasoline is pushed into the carburetor it is sprayed through a small jet where it is turned into a gas (vapor). The gasoline is evaporated. Where does the heat come from to evaporate the gasoline? The carburetor. The throat of the carburetor can get below 32° F when the outside air temperature is above 40° F.
Evaporation of the fuel takes heat from the incoming air, which causes condensation. Ice forms inside the carburetor throat, causing dangerous engine conditions for landing. It is surprising, but the time this is most possible is around 40o to 50oF, as there is more moisture in the air at that warmer temperature. Before landing, pilots pull the "carb heat" knob to allow warm air to come into the carburetor, melting any ice that might exist. This keeps the engine running smoothly during the critical time during landing.
	For three years I worked at Red Devil Mine on the mid-Kuskokwim River. Much of the time, I ran the mill. Mercury and sulfur are found together in a red crystal called cinnabar. The way the mercury was removed from the rocks was to heat the ore above 937o F. The mercury evaporates from the cinnabar at that temperature. The gasses were then passed through huge metal tubes, like a massive pipe organ, where they were cooled. The mercury was then condensed and dripped out of the metal tubes as a shiny liquid. This is considered too dangerous today, and other methods are used.
Years ago, I taught in a little village close to Mt. Denali. Many days I could look out and see a little cloud behind the peak of the mountain. I wondered why it didn't blow away. It seemed to be hiding behind the peak for hours and hours. I thought about this for a long time. It didn't make sense to me. Why didn't the little cloud blow away? Then, one day, I understood. The cloud seemed stationary because it was constantly being formed and evaporated. What I saw was a process, not a stationary cloud. Tourists who come to see Denali in the summer often find the whole mountain covered in fog and clouds, even on a sunny day. If there is enough moisture in the air, the cold mountain forms its own clouds all the way down to the base. Why does your mom tell you to dry your hair before you go outside?
	Questions 1) List five more situations where we try to increase evaporation. 2) List five more situations where we try to avoid evaporation. Think of foods. Think of all liquids. Think of petroleum fuels. 3) Condensation is . . . 4) Evaporation is . . . 5) If you want to increase evaporation, what would you do? 6) If you want to decrease evaporation, what would you do? 7) If you want to increase condensation, what would you do? 8) If you want to decrease condensation, what would you do?
	REFLECTION Charlie makes a teapot by putting a wire handle on a coffee can. He notices that every time he makes a new one, it takes longer to boil water. He wondered about this for a long time, until he finally realized that the new can was shiny. The shiny surface reflected the heat. Once the can was blackened by the fire, it absorbed the heat and boiled water quickly. He tried to keep track of his old blackened teapot after that. Reflection of thermal energy (heat) or light is when it bounces off a surface rather than going into it. A ball will bounce (reflect) well off a hardwood floor. A ball will not bounce (reflect) well off a rug. In a similar way, light and thermal energy (heat) reflect better from some surfaces than they do from others.
	Charlie knew that the sun is stronger in the summer than in the spring. Yet he became snow blind several times in the spring, and never did in the summer. He wondered why. He finally realized. In the spring, the sun's light was reflected from the snow, coming at him from all directions. In the summer, the ground surface absorbs the sunlight that strikes it, and the sunlight comes to his eyes only from the sky. What did the old time Alaskans use to prevent snowblindness? How did this work? The next year Charlie went to Bristol Bay to fish. He was on the ocean and burned his eyes again. How would you explain this? That fall, Charlie was watching a football game on TV. He noticed that some players had black grease under their eyes. How could you explain this to him? He started to notice more things about reflection. The next spring as he traveled with his snowmachine on the lake, the black cap fell off a gas can in his sled. The next day he went back, but he had a very hard time to find it.
	It had melted deep into the ice. How could you explain this to him? As a test, he left a rock on the ice. Within two days it was almost six inches into the ice. Why?.
	Charlie went fire fighting outside in the Lower 48. He was a little nervous because he heard the trees there are much bigger than Alaskan trees. When he arrived, he heard about fire shelters that every firefighter must carry. He tried to picture how big a fire shelter must be to insulate people from the intense heat of a raging fire. He was amazed. Folded, they are smaller than a five pound sack of sugar. When he opened his up to see, he discovered why they can be so small. The shelter is made of very shiny foil covered with plastic. From his new teapot he knew how reflective shiny surfaces are. He knew he would be fairly safe if he could get under his shelter before the fire came his way. He would be as safe as cold water in a shiny teapot!
	My wife's aunt bought a new tent for spring camp. She was very happy until she moved into it that April. It was very cold inside, even when we had the wood stove burning. I thought about this for a long time. I finally understood. It was a brown canvas tent. We were used to white tents. The white canvas reflects the heat of the stove back to you. The brown canvas absorbs most of the radiant heat, and reflects very little of it back to us. We learned that white tents are warmer than brown or dark green if you put a wood stove in them.
	Old timers in Alaska used to hang sheets across the ceiling of the cabin. This allowed the weak light from the kerosene lamp or candle to reflect back down to the room. The ceilings and walls of most cabins heated by wood stoves become quite dark after a while from the smoke. We even pinned aluminum foil all over the ceiling of one cabin as it was so dark and depressing. You are out in the woods on a hot summer day. You have to wear a shirt to keep the mosquitoes off, but you don't want to be too hot. Will you wear your black shirt or your white one? Nick's boat froze into the river ice because he didn't pull it out in time. It is just before breakup, and he has to get it out. He doesn't want to chop it out because he might
	make a hole in it. His brother said he should put wood stove ashes and dirt around the boat. Nick isn't sure what his brother meant. Do you think this will help? Maria noticed that once there is bare ground showing in the spring, the snow melts back from that spot. How would you explain that to her? Why does the snow melt faster from the exposed sides moving towards the center of the snow bank rather than from the top surface downward?
	Why do nights in September seem darker than nights in October even though September has more hours of daylight? The local store painted the gas tanks with silver paint. Melissa couldn't understand why. Can you tell her?
	BOTTOM LINE OF ALASKAN SCIENCE (my view) For years I askedmyself the questions, "What is the root of all science in Alaska? What is the bottom line?" There were two things that always came to mind when I thought about this: Migration Stored chemical energy These do not include northern lights, earthquakes and other earth science issues, but the more I thought about it, the more I saw life and physical science issues linked with these two topics. MIGRATION Animals migrate from one place to another for several reasons, among them being food, reproduction and living conditions. The caribou migrate to different areas as the herd consumes the moss in one area. The salmon are born here in Alaska, migrate to the open ocean where they feed and grow, then return to reproduce. The whitefish migrate into the shallow lakes in the summer to feed in the "solar ponds" that are across much of Alaska. However, they must migrate out of those lakes before winter or they will be frozen into the ice in the shallow water. Ducks, geese, swans and other birds migrate to Alaska to feed and nest. They migrate to warmer climates when the ice starts to form on the lakes and rivers. When animals migrate, it is usually to an energy source or for energy reasons.
	As the animals migrated, the Native people also migrated to follow the resource. Migration was much more a part of life long ago than it is now. Migration for food was really a search for stored chemical energy. Identify the fish and animals in your area. Identify their migration patterns. Some migrate far, others not far at all. Even today people migrate, but for different reasons than long ago. I have noticed that many Alaskan villagers migrate to the larger cities after dividends arrive, then migrate back to the villages when the shopping is done. STORED CHEMICAL ENERGY In Alaska, we have certain energy needs: Food for our bodies to grow and work. Energy to travel. Energy to heat and light our homes and schools. Our energy needs are fairly constant, although they are greater in the winter than in the summer. Alaska is a land of extremes. In the summer we have extreme amounts of light. In the winter we have extreme amounts of darkness and cold. When the salmon run, there is an extreme amount of food available. At other times there is an extreme shortage of food. Energy must be stored if people and animals are to survive. In Barrow there might be little to eat until the whalers strike a whale, then there is more than enough for the whole village. In the interior, there might be little to eat until the caribou pass through, then there is more than enough. Some of our energy we get directly from the sun, but most of our energy comes from stored chemical energy in our foods and fuels. If chemical energy could not be stored, there could be no life in Alaska.

	Questions to ponder What are some examples of stored chemical energy in your village or home? You dribble a basketball down the floor and make a layup. Where does the energy come from to do that? You put wood in the stove, or turn the knob on the oil heater, and heat comes out of the stove. Where did the heat energy originate? You are hungry, so you hunt caribou. But the caribou see you from a long ways off and run away. Where did the caribou get the energy to run away from you? Where did that energy come from?
	Over a hundred years ago, whalers came from the East coast of the United States to hunt whales. What were they really harvesting? Through no concern for the whale population, the whalers stopped whaling. Do you know why?
	You get a whitefish out of the freezer in January. You cook it for supper. After eating, you do not feel hungry for many hours. Where did the energy come from that your body used during those hours? One gram of fat has twice as much stored chemical energy (calories) as a gram of grain, rice, potatoes or meat. When our bodies take in more energy than they can use, they store the energy as fat. Fat stored as chemical energy in our bodies or the body of an animal is concentrated energy. Black bears store enough fat in the fall to provide their bodies with the energy to stay warm and alive all winter long. Of course their bodies slow way down during hibernation. When our bodies use more energy than we take in, we change the fat to usable energy. We store our money in banks, and store our energy in body fat. Salmon store energy as oil, which is a fat. As they travel upstream, they draw upon the stored energy in the oil to get to the spawning grounds. Bull moose are fat before the rut, but do not eat during the rut. Their energy is stored as fat. By the end of the rut, they have consumed the fat and are very lean.
	Fat also serves as insulation for many animals. Whales, seals and walrus have a layer of fat that helps keep their body warm even in cold water.
	Identify the animals in your area. Do they get fat at any time during the year? At what seasons? What do they eat to become fat? Are they ever without fat? If so, what causes them to become lean? Traditional lamps in Alaska were made from animal fats, whale, seal, bear, moose etc. The stored chemical energy was released when burned in a stone lamp with a moss wick. What kind of fuel was used in traditional lamps in your village? Make a traditional lamp and test different oils.
	THE THRESHOLD Molecules are made of atoms held together by chemical bonds. Some (but not all) chemical bonds have stored energy. It took energy to create those bonds. Energy is released when they are broken.
	Example: When plant fibers are burned and the chemical bonds are broken, heat and light are given off. Why doesn't a piece of wood or paper burn by itself when it is sitting on the floor or table? First we must put a little energy into the wood or paper to release all of its energy. We might use a match to light the paper, but will have to use kindling or lots of cardboard to get the wood burning.
	The idea is this: To release chemical energy from a substance, often we most put energy into it to obtain the release. A stand of timber might grow for 100 years, but when the forest fire comes, the chemical energy that was stored in a tree is released. This releases the energy in the trees close by, which releases the energy in the trees close to them. Soon there is tremendous energy being released that started from something as small as a campfire. What energy is put into the cylinder of a snowmachine to bring the fuel over the energy threshold so it might burn? What energy is put into the firebox of a home heating furnace to bring the fuel over the energy threshold so it might burn? Why doesn't the fuel start burning while in the storage tank? You put wood in the stove, and 12 hours later, there heat is still coming from the stove. Where did the energy come from that was in the wood? How is the release of the energy controlled? What sources of energy are available in our bodies to bring our food over the energy threshold so it might give off chemical energy that we can use for daily life? Why are many homes lined with sheetrock? Identify the seasonal migrations of the traditional Native people in your area. Why did they move about? Of these moves, how many were directly related to pursuing a stored chemical energy source? You race after a herd of caribou with your snowmachine. Where does the energy come from for you to go that fast? Where does the caribou get it's energy? If you had to run after the caribou, would you catch it? Name three types of batteries. Name at least ten items in your everyday life that use batteries. Where does the electrical energy come from?

Write to me at:

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