The Rainbow Sample Lessons

The Rainbow

Red Section

Physics—The Study of the Principles that Govern the Universe

A thorough study of science might best start with the science upon which all other sciences are based. As surely as God created Adam, he placed in him a curiosity. With that curiosity he also provided him with the ability to gather knowledge and to apply it in the solving of everyday problems. In our study, we will not approach the vast creative abilities of our Creator, nor will we presume to approach his wealth of knowledge. Instead, we will seek out solutions to the practical problems that face us as people while continuing on our greater mission of pleasing Him who gave us this unspeakable blessing of fruitful curiosity.

To study physics is to attempt to know and understand the principles that God used in creating and sustaining the universe. These are the simplest (if not easiest) of all observations. What are space and matter, and what are their properties? What are the basic forces that operate in the universe and what are their effects on matter? The science of physics provides a viewpoint from which we are able to solve many of the problems we face. We will now begin to help you to see from that viewpoint. But be prepared—you will see things you have never seen before, nor anticipated.


1: Inertia and Flying Objects

Where does a person begin to study the design that has gone into the universe? Well, if you’re human (and I’m assuming that you are), the best way to start is to be aware and take notice of the world around you. The most famous scientists in history were particularly good at noticing and recording the things that they noticed. There were probably others who were equally good or even better at noticing, but didn’t write what they noticed. We know nothing about those.

Take, for example, the scientist who is the subject of this lesson. One of the most famous scientists of all times, Sir Isaac Newton (1642-1727), was once on recess for a year and a half while waiting for a bout of the bubonic plague to be eliminated from his school. During this time he wrote the founding observations for the mathematics of integral calculus. What do you do in your time off?

Look about you. Notice that you are surrounded by objects. No matter where you go, or what you do, objects are everywhere. Go ahead, just try getting away from objects. You can’t do it! These are the subjects of the science of physics: objects, all objects, and the things that happen to them.

Looking around, we notice right away that most objects—books, chairs, desks, pencils, pads of paper, trash cans full of crumpled paper—appear to be lazy. They don’t seem to move around unless we do something to them. This is very important. Just imagine what your day would be like if all of these objects were flying about aimlessly. Life would be a continuous hazard and horribly unpredictable.

No, the universe isn’t nearly as complex as it could be. There are laws—rules of nature—that all objects obey. Some of the most important laws are the simplest:

 

Rule 1: Objects stay where they are unless somebody throws them.

 

Rule 2: Once objects are thrown through empty space, they keep traveling at the same velocity and in the same direction until something stops them or changes their course.

 

These two rules taken together are great simplifying rules of the universe. To demonstrate the first rule, place a pencil on the table. (If your table is lop-sided, the experiment will be a dud.) Now go away, and come back after two million years. See? The pencil is still there.

To demonstrate the second rule, roll your pencil gently across the table top. If it keeps going forever, the second rule is true. If it stops, the second rule is still true, but something has acted on the pencil to stop its rolling.

Congratulations! You’ve just mastered one of the great scientific observations of all time. These two rules make up Newton’s First Law of Motion. Objects at rest remain at rest unless they are acted upon by some force. Objects in motion remain in motion at the same velocity and in the same direction unless acted upon by some force. The property of an object that makes it resist changes with regard to its motion is called inertia.

This is really what physics is all about—making observations that simplify a complex situation so that we can understand what we see happening and may even be able to predict what might happen.

 

Exercises:

 

1.      If a perfectly round marble were placed in the middle of a perfectly flat table and left alone with no other influences on the marble, what would happen? Why?

2.      In the example mentioned in the text, what forces were acting on the pencil to make it stop rolling?

 


2: Jumping off Asteroids in Outer Space

Every physicist would love to live in a complete vacuum, that is, a universe with everything sucked out of it. Experiments would be much easier to perform if there were no air or gravity to interfere with them. Of course, we would all die, and that would slow our scientific progress.

So instead, we will have to live on earth and be content imagining what it would be like in a place where there is no gravity and there are no objects (not even air) to get in the way. But after we are done considering this odd place, we return to reality so that we can apply what we’ve learned to the more complex situation in which we live.

Let’s start out our day in empty space by taking one step toward the grocery store. But there is no ground to push our feet against, and there is no object to pull against. There are no outside forces such as pushes from wind or gravity acting on us. Just as we learned in our last lesson, we are stranded by our inertia.

Now imagine that there is a small asteroid within reach. Using the asteroid, we point ourselves toward the grocery store, put our feet on the asteroid and kick ourselves toward the store. We find that we are suddenly flying in the right direction. Because there are no forces acting on us, we will continue to fly in the same direction and at the same velocity until…Oh, no! Smack…right into the grocery store! We forgot that in space we can’t stop because there is nothing to cause us to stop.

Nothing has been illustrated yet that we did not already know: First, objects at rest remain at rest until acted upon by some force. Second, objects in motion remain in motion until something stops them.

There is yet something to learn from our unfortunate trip. How fast did we travel? Do you agree that it depends upon how hard we kicked? The harder we pushed (or the stronger our leg muscles), the faster our trip would be. This is a statement of Newton’s Second Law of Motion:

 

For an object of certain mass, the greater the force applied to the object, the greater its increase in velocity over time (acceleration).

 

The opposite is also true:

 

For an object of certain mass, the lesser the force applied to the object, the lesser its acceleration.

 

You will notice that the force of our kick lasted for only a short time. During the time in which the force was applied, we were increasing velocity, or accelerating. After we stopped applying force and we were just flying through space, we were no longer accelerating, but we continued to fly at the same velocity. So the harder we kicked, the greater our acceleration during the kick, and the greater our velocity after the kick.

Do you also agree that how fast we traveled would depend upon how massive we were? The more massive something is, the harder you have to push to move it, and the more slowly it accelerates once it starts moving.

Now, what do you think happened to that asteroid—the one we kicked? As we started flying toward the store, the asteroid must have flown the opposite way. For as our feet were pushing against the asteroid, it was pushing against our feet with an equal force in the opposite direction. This is Newton’s Third Law of Motion:

 

For every action, there is an equal reaction in the opposite direction.

 

Does this mean that the asteroid would pick up speed as fast as we did? No. That would depend on its mass. And, just as we would expect, if the asteroid had 10 times more mass than we had, its acceleration would be 1/10 of ours.

 

Exercises:

 

1.      What two things do you have to know in order to determine the acceleration of a rocket in outer space (where gravity is absent)?

2.      If you are traveling in outer space, what do you need to stop yourself?

3.      Is it possible to use an object to stop yourself without putting any force on that object?

4.      If you knew how much force you placed on the object that stopped you, would you know how much force was applied to you at the same time?

 


Yellow Section

Chemistry—A Study of Substances, Their Properties, and Their Interactions

Welcome to the Yellow section. Here we focus on the discipline of chemistry: the study of different kinds of stuff (substances) and what they do to each other (their interactions). In this section we will learn some of those fun and seemingly magical chemical reactions; but more importantly, we will learn how their “magic” works. Please begin now with the first lesson.


1: Impress Your Friends!

Recall that all matter is composed of atoms, and that atoms are composed of protons, neutrons and electrons. Protons and neutrons are packed tightly together in the center or nucleus of an atom, and electrons orbit the nucleus at high speed. The number of positively charged protons tends to be the same as the number of negatively charged electrons, keeping the charge of an atom neutral (neither positive nor negative). Protons and neutrons make up most of the mass of the atom, while electrons have some—but little—mass.

Second, recall that an element is made up of atoms having a certain number of protons in their nuclei. Each atom of hydrogen, for example, has one proton in its nucleus. All matter is made up of some combination of elements. If we could group atoms together by their number of protons, the result would be separate pure elements. Pure gold is a collection of atoms of gold, each having 79 protons. Because they are common or useful, some elements (like copper and mercury) have names we recognize.

No element is present in nature in its absolutely pure form. Although we can purify them from their natural forms, in nature they are found combined with other substances. So when you look around you in your world, you will find many different substances. But these are not simple elements. They are complex combinations of elements. The study of chemistry involves taking a closer look at those substances and seeing what they are made of and how they are arranged.

Atoms of different elements or of the same element can be joined together by the natural (mostly electric) forces to form molecules. For example, an atom of oxygen can join together with two atoms of hydrogen to make a molecule of dihydrogen oxide, which we usually call water. Molecules made up of atoms from two or more elements joined together are called chemical compounds. Pure water (water made up of only dihydrogen oxide molecules and no other) is a single compound.

We begin our study in the next lesson by looking at the different forms of matter.

 

Exercises:

 

1.      Silver is the name of an element. How many types of atoms make up silver?

2.      A ______________ is made up of atoms held together by natural forces.

3.      Two or more elements joined together make up a _________________.


2: Packaging Stuff

So you want to understand stuff, eh? I mean, you want to understand the make-up of matter. Well, you are on your way, bright student.

Once upon a time there was a stuff packager. Her job was to package stuff. She picked the right sized box to put in just the right amount of stuff. But this wasn’t just any stuff packager; she had the special ability to pack stuff in space. What I mean is, she could move stuff around in space and it would stay where she put it. That’s why they paid her the big bucks. Sometimes she left out the space and packed things tightly. At other times she would put in a little space and pack things more loosely. At yet other times, she would pack things so that there was mostly empty space and very little stuff.

Interestingly, when she packed differently, the stuff acted differently. When she packed tightly, the stuff got stiff. Stiff stuff can sometimes be useful. When she packed more loosely, she found that the stuff filled the container from the bottom up, but the stuff never got stiff. She could put her hand into the stuff and it would move out of the way for her. When she took her hand out of the container, some of the stuff would be on her hand and she would have to wipe it off. Finally, when she packed with mostly empty space, the stuff moved freely about the box. Sometimes stuff bumped together with other stuff. She had to shut the lid quickly or the stuff would bump right out of the box to spread out within the packaging room. But if she got the box closed on the stuff, it would just spread itself out within the box. If you listened carefully, you could hear that stuff bumping around in there.

What magic did this lady possess? None. You see, this lady was extremely small. The stuff she packed was particles—atoms and molecules. Particles that pack together tightly and have a love for each other make stiff solids. They are rigid, and the movement of their particles is minimal. Particles of liquids have less love for each other and move around more freely, but not as freely as particles of gases. While liquids fill a container from the bottom up, gas molecules spread out to fill any container all the way to the limits.

Compare the types of matter that we’ve seen. The floor is solid, water is liquid, and air is gaseous. That may not seem like much of an observation, but if you think about it, almost every kind of matter is either a solid, a liquid, a gas or some combination of these. There are also a few substances like gelatin and ice cream that we call semi-solids, but for the most part everything fits nicely into one of these three categories called the phases of matter.

Matter sometimes undergoes a change from one of these phases to another. The way you cause matter to change phases is to put in or take away energy. For example, tightly packed solid molecules, when heated up, start moving more rapidly; this movement expands the substance and creates more distance between the molecules. If enough heat is applied, the forces binding the particles together are broken and the particles become more loosely arranged. At that point they become liquid. If you continue to add heat, they can break apart even further to become gas. To return these particles to their original state, all that is necessary is to cool them down.

When you put water in the freezer, heat leaves it and its temperature drops. When the temperature drops, the liquid changes to a solid—ice. When it warms back up to room temperature, it changes again from solid to liquid. This is not so thrilling because we’ve seen it since we were little kids. What is nifty is that other liquids also change to solids when they get cold (although some liquids have to get really cold before they turn to solids). Also, gases change to liquids. This illustrates that gases are just liquids hanging loose, and that liquids are solids hanging loose. How loose the particles of a substance are depends on the strength of the forces attracting those particles and on the amount of heat energy around them.

What happens when you boil water? Steam comes off the water. We say it evaporates, or turns to vapor. And if you boil the water long enough, there will be no water left in the pan. That’s because it all turns to steam. But what is steam? It’s a gas. You might say it’s water gas. When steam cools, what happens? It turns back into water.

Water turns to ice when its temperature falls below 0ºC. It turns to gas if the temperature rises above 100ºC. But what about other liquids? Do they change from solid to liquid or from liquid to gas at the same temperatures? No. Each solid has its own unique melting point at which it turns to liquid, and every liquid has its own unique boiling point at which it turns to gas. These are just two facts of nature—observations about the way heat affects matter. At a later time, we will learn how important the melting and boiling points of different compounds are. In fact, we will learn that life as we know it would be impossible without the melting and boiling points of water being just as they are.

When a pan of water is placed on a burner, the temperature of the water starts going up. The heat passes from molecule to molecule. One molecule heats up and passes some of that heat off to its neighbors. Occasionally a molecule near the surface of the water will become so energetic with all of the heat it has received that it will yell “yowee” and break free into the air. Its neighbors will heat up in the same way until they are all bouncing around trying to get out of there. Each time a hotter molecule leaves the pan, it takes some of that heat with it. So while the heat beneath the pan heats up the water, the leaving of the overheated molecules cools it down. The temperature of the water that remains in the pan stays the same until every molecule has escaped and all the water has been boiled out. That temperature, called the boiling point, is precisely 100°C. How did it turn out to be exactly 100ºC? Simple. Some scientist made it up.

Because of this property, the boiling of water can be used to keep a constant temperature. If a recipe tells you to simmer soup in a pot for three hours, the soup will remain at its boiling point (which will be near the boiling point of water) as long as liquid water remains in the pan and the stove provides enough heat to keep the soup boiling. When all of the water is evaporated away, there are no more particles of water to keep taking heat away from the pan. The temperature will rise quickly (and the stuff left in the pan will burn).

Once steam is made by heating water, the steam will go out into the cool air and its temperature will drop to below the boiling point again. Steam will cool and the tiny water droplets will combine to make liquid water again. This conversion of steam to water is called condensation. Condensation is the process by which rain forms in clouds, dew forms on morning grass, and fog forms in cool moist air.

 


Exercises:

 

1.      Why doesn’t fog form in the middle of the afternoon?

2.      On which day is snow more likely—a day when the temperature is -20ºC, 0ºC, or 20ºC?

3.      If you wanted to melt a stick of butter without burning it, you could melt it at 100ºC. What is a practical way of doing this?


Blue Section

Biology—The Study of Life and Living Things

Just about every textbook on the subject of biology—the study of living things—will be found to begin with a lesson on how life originated from non-living things. Well, we were not there to witness the origin of life, nor do we have adequate scientific evidence to demonstrate how life arose. There are theories on the origins of life, some weaving together a large amount of scientific evidence while others are nearly unfounded. Of course, the theory most widely held among scientists on the origin of life is the theory that all living organisms evolved from one simple, single-celled organism that was successful in multiplying. The theory goes on to suggest that all of the different organisms present today are the result of changes within groups of organisms that arose from this common ancestor.

This theory, which we will call the general theory of evolution, is so widely accepted in scientific circles that a person can hardly be a scientist without understanding it. That doesn’t mean that a person has to believe it is all true in order to be a scientist. I personally know many scientists who do not adhere to this theory. These scientists are prominent in their disciplines: one is the dean of a school of science education, one is the chief cardiac surgeon at a major research hospital, one is a leader of a research institute, another is a chief researcher in a medical genetics lab, yet another is the president of a high-tech company. Their lack of belief in this most popular theory does not in any way prevent them from excelling in their disciplines, making new discoveries, publishing articles in respected research journals, or contributing to the advancement of knowledge. On the contrary, sometimes it takes a person who is thinking differently from others to see things that others do not see. It is this diversity of thought that causes the truth to be preserved. If everybody thought the same things and were wrong on the same things, the truth would be forever lost.

In this text we will attempt to teach the general theory of evolution because a good education in the sciences requires it. We present it as a theory—a working model into which scientific data are fitted—but which we ourselves do not accept. As new observations are made, models will be altered, radically changed or altogether discarded. After many years of study and observation in my discipline as a microbiologist, I hold that the general theory of evolution is in serious error and is entirely inadequate for explaining a great volume of scientific evidence. I also hold that the universe was created by a Supreme Being possessing design and creative capabilities far beyond our comprehension.

The belief in a Supreme Being is not as uncommon among scientists as students are often led to believe. In a recent study, 40% of scientists were found to believe in a Creator. Science is full of challenges, including challenges to the Faith. In time, you can accept and answer those challenges without allowing them to erode your confidence in what you have learned from God.


1: So What’s Life?

Perhaps the first, most important question to be answered in the study of life is the nature of the subject itself: What is life? The Bible and science define life differently. The Bible says, upon the creation of Adam, that God “breathed into his nostrils the breath of life, and man became a living spirit.” Note that it says, not a living body, but a living spirit. A spirit has no physical dimensions, which places it outside the realm of science. Science defines life not by what it does not know or understand, but by what it does know and understand. We can’t see a living spirit, but we can see a living body and know what it does. So science defines life as those characteristics held in common by living bodies.

At this point we agree to play a “game.” We will look strictly at “scientific” life, or life in the physical sense. Let us not forget that we are but playing the game. Sometimes I like to play the game, and sometimes I do not. In this book we will play the game so that you will understand the “scientific” viewpoint, but we will point out differences of viewpoints where we feel it is helpful.

So life, by scientific definition, is the set of characteristics shared by living bodies:

1.      They are made up of one or more cells. (We will learn more about these in the next lesson.)

2.      Their cells contain deoxyribose nucleic acid (DNA). (We learned something about this in our study of chemistry. We will learn more as time goes on.)

3.      They consume food and produce wastes.

4.      At some point in their lives they may reproduce—give forth new living beings like themselves.

5.      They tend to be self-maintaining. That is, they use energy and raw materials to build themselves, to grow and to repair damage done to them.

There are many forms that fall within this definition of life. These forms, to be defined later in our study, include archaea, bacteria, fungi, plants, and animals. By most scientists, humans are included among the animals. This is because humans are regarded by many scientists to have evolved from animals, or because humans fit a scientific definition of what it means to be an animal. In this text, even if we talk about humans as though they were animals, we recognize the supreme position over the animals which was given to man by God. We also recognize that, although similar to the animals in many ways, man is different from the animals in that he is created in the image of his Creator.

When we define life according to the scientific definition, problems arise in figuring out what is alive and what is not. There is not a clear distinction between the living and the non-living. Some “non-living” things act an awful lot like living things. Examples of these include prions [PRI-ons], molecutes and viruses. These curiosities take on some of the characteristics of life at different times, but they are not generally regarded as “living.” Way down the road we will learn how to handle these oddballs. For now, we will attempt to learn about different forms of life according to the way they are commonly grouped by biologists.

Perhaps the most basic of all life characteristics is reproduction—the ability of living things to form other living things. Some living things produce asexually (“not” + “sexually”). That is, one single organism can form a small package of living material that can break off, shoot out, or otherwise leave the parent to become a separate living thing of the same kind. A second type of reproduction is called sexual reproduction. This requires two organisms of the same kind. One of these organisms, referred to as the male, passes a package of DNA to a female of its own kind. This genetic material combines with a similar package from the female to begin the formation of a new individual. Whether sexual or asexual, the ability to reproduce is enough by itself to separate all living things from the non-living.

 

Exercises:

 

1.      Which of the following would the field of science directly address? (Give the letters of all correct answers.)

 

a.      the Biblical definition of death

b.     signs that a living organism has ceased to live

c.      life after death

d.     everyday habits of early cave-dwelling people

 

I.                    New bacteria (daughter cells) are formed from their parent cells by pinching off directly from the body of the parent. Is this an example of reproduction?

 


2: Organization in Living Things

Organization at every level—that’s the way to describe our universe. I once had an old professor at the university who said, “Our universe is much more organized than it need be. I think you should thank whoever you believe is responsible.” He’s right. Our universe is highly ordered.

We have already talked about the orderliness of matter, orderliness which is caused by the basic forces. We’ve talked about the organization of particles into atoms, atoms into elements, and elements into molecules. But the organization doesn’t stop there. Living things represent a higher level of orderliness. In the living, molecules can be large and have organization which allows them to do something special. They can be built for a specific job or even have special “active sites” that carry out specific tasks. They can contain codes for storing, decoding and using information. They can even be used to communicate information to other living bodies and to decide the features of their offspring.

These highly organized molecules are further organized into cells. Just as atoms are the basic units of matter, cells are the basic units of life. All of the characteristics of life are displayed only when molecules are arranged and work together as cells. As we introduce cells, we introduce life. But our study of organization is not finished. Only the simplest living things live only as cells. These cells can be further organized to make different kinds of living things.

A living thing which exists free from other living things is called an organism. An organism can be a person, a dog, a tree, a fish, a worm, a mushroom or an insect. It can also be something much simpler like a single-celled organism: a yeast cell, a paramecium, or the smallest of all organisms, a bacterium. A human skin cell may be alive and show all of the signs of life, but it is not an organism by itself because it does not live free from other skin cells, or from blood, or nerves, or any other cells that make up the human.

Organisms can be organized at any number of levels. Some are single cells that live alone. Others are collections of similar cells. The most complex organisms have many different kinds of cells. They have groups of similar cells organized into tissues; different kinds of tissues come together to form organs. These organs are “body parts,” each having its own specific purpose. Examples are a hand, a stomach, a liver or a heart. But if a body were made up of a random assembly of parts, it would be an ugly monster! These parts are further organized into the functioning systems that make up the organism.

To illustrate the organization represented by these complex organisms, consider the human circulatory system. This is the system that carries food and oxygen to all of your body’s cells and takes waste away from those cells. The human circulatory system is made up of several organs: a heart, arteries of different sizes that carry blood away from the heart, capillaries that take blood to the individual cells, and veins of different sizes that return the blood to the heart. The heart, arteries, blood, capillaries and veins are the organs of the circulatory system.

Each of those organs is made up of various tissues. For example, the arteries have an inner lining called “epithelial tissue,” a middle layer of connective tissue, some muscle tissue, some nerve tissue, and an outer coat of connective tissue. The tissues are made up of cells, and the cells are made up of molecules, many of which are highly organized themselves. Each molecule is made of atoms, and the atoms are made of subatomic particles (protons, neutrons and electrons).

Notice how highly organized this one system is. It is just one of many systems that make up the human body. Later on we will study these systems in greater detail. Even if you already have a sense of amazement at the human body, your amazement will grow as you learn more of the details of how it works.

At each level of organization, every component part obeys the laws of physics. Organisms with such a high level of organization as we have just described are referred to as “higher organisms,” as compared to simpler “lower organisms” like those made up of a single cell.

The amount of organization found in even lower organisms is astounding. Just imagine the amount of potential energy represented by such complex organization. Given that we live in a universe where things tend toward lower potential energies, it takes a tremendous amount of energy to produce and maintain that high level of organization. When an organism dies, it decomposes rapidly back to more stable forms of matter. Life as we have defined it is a brief and unlikely lift to an exquisitely high level of potential energy. I think you should thank the One responsible.

 

Exercises:

 

Unscramble the words to fill in the following blanks. These sentences describe living organisms at each level of organization beginning at subatomic particles and ending at organisms.

 

1.     Atoms are more organized than _________________ (bautmiocs sieaptcrl) and are the units that make up the different _________________ (tmeeenls).

2.     _________________ (locumeels) are made up of the atoms of a number of elements bound together. In biological systems they may be large and complex even to the point of containing encoded information that is passed on from generation to generation.

3.     A _________________ (lecl) is the basic functioning unit of all living things. It is a complex orderly arrangement of molecules constantly carrying out chemical reactions that allow it to function as a living organism. In “lower animals,” a single one of these units may constitute an entire organism. In “higher animals,” several or even billions come together to make up _________________ (isssuet) which in turn make up _________________ (soargn), which work together in _________________ (sssymet) which make up an entire _________________ (gorniams).

 


Applications of the Rainbow

Our environment is our surroundings. At a given time we might be surrounded by the ocean or the sky. A few humans have even turned up in outer space. Although most of us can’t go there yet, with the help of a telescope we can at least see remote areas of the universe far beyond our immediate environment. In one way of thinking, the universe is our environment. In a narrower way of thinking, our environment is the biosphere of earth—the locations on earth where life exists. In order to get to know our dwelling place, we start with the big picture. We will look from the center of the earth to the edge of the universe, then break this expanse down into smaller pieces so we can understand in greater detail those places where we spend most of our time. But first, let’s look at the way scientists study their surroundings.


1: Scientific Method

Just as science is a collection of knowledge, scientific method is a way of collecting knowledge so that the results can be trusted. There are accepted ways of confirming results. Although the word science is an old word, what we now call the scientific method is relatively new, being at most only a few hundred years old. Despite the clear-cut methods laid down in many textbooks, there is no simple set of rules that make up scientific method. Instead, any method that is logical and provable will be accepted by scientists.

Generally, in order to prove something, a scientist finds an experiment which will answer a simple question by comparing a treatment and a control. For example, what effect does ammonia have on the growth of corn seedlings? This is a basic question to which we would like an answer. I called it a basic question because it is simple. An example of a complex question that would be difficult to answer is this: What effect does ammonia have on the stock market? The problem with such a question is that so many factors affect the stock market. If ammonia had any effect, it would be hard to separate from the effects of all those other factors. But we can set up a simple experiment to test the effect of ammonia on the growth of corn seedlings. All we have to do is:

1.     grow some corn seedlings

2.     weigh them

3.     place them in test tubes under controlled lighting and temperature

4.     add water (which has no ammonia in it) to the test tubes

5.     add a known amount of ammonia to some of the test tubes—these are our experimental subjects (“the treatment group”)

6.     be sure to leave some of them without ammonia—these are our control subjects (“the control group”)

7.     allow them sufficient time to grow, checking their weights periodically

8.     compare the results from the treatment group with the results from the control group to see if they are different

If there is an effect, and if the effect is not too tiny to be seen by our method of comparison, the test will have answered our question. That’s the scientific way. Every experiment has a control (or controls) to which we compare our experimental subject (or subjects). The answer to our question is in the comparison.

Now that you see how easy it is to be a good scientist, all that’s left is learning a few terms. We started out with a simple question. What effect does ammonia have on the growth of corn seedlings? We must have had a reason for asking that question. From the start we suspected that ammonia would have some effect on the growth of corn seedlings. Because we know that plants require nitrogen and that ammonia contains nitrogen, we suspected that adding ammonia to a plant’s water would increase its growth rate. We even suspected that a plant without added nitrogen would have a hard time growing at all. So we formed a hypothesis. A hypothesis is an educated guess. Based on my education, I guessed that adding ammonia to a corn seedling’s water would cause the seedling to grow faster (unless I added too much and it killed the plant).

The second term is familiar to most people. The term is experiment. The scientific definition of experiment is “the test of a hypothesis.”

The third word for you to remember describes what makes you able to form a hypothesis. You are able to do so because you have some background information to go on. Science has made a lot of information available concerning the growth of just about every plant, but if that information were not available, there would have to be something in your mind telling you to try adding ammonia. In other words, you must have some model for plant growth in your mind suggesting that nitrogen would be helpful. That model is called a theory. A theory is a mental picture of how a system will work. If you think your model is a good one, you’ll share it with others so they too can have a mental picture. Together you can learn the answers faster and check each other’s answers. If you work for a company, a mental picture of how a system works can be among the company’s top secrets. The company officers may prevent you from ever explaining it to anyone!

To summarize, a scientist uses his mental picture (theory) to come up with a hypothesis, then tests that hypothesis. The hypothesis being tested is a simple statement which the scientist determines to be either true or false by comparing a treatment (experimental subject) with a control subject.

In order to conduct a test you must have an objective way to measure the results. You can’t simply say, “Yep! Just as I thought; this one looks bigger than that one.” Instead there must be a method that does not depend on your opinion. Subjective testing is not sufficient because it can lead to bias in your results. That doesn’t mean that scientists are always objective thinkers. In fact, scientists often hold to opinions that are wrong. That’s why the test has to be objective, so that the scientist’s opinion is not reported as a fact when it is actually wrong.

Anytime a scientist presents a theory as a fact, he is no longer acting as a scientist. If you ever hear someone talking about the theory of human evolution as though it were a fact, tell him you are not interested in his opinions. Tell him to present only the facts and let you decide for yourself. Chances are, he won’t even know the facts. If he does know some facts, you probably won’t find that they make the theory convincing.

 


2: The Earth

In our journey to the outer reaches of our environment, perhaps the best place to begin our observations is close to home—right here on earth. The earth is a large ball measuring 8,000 miles in diameter. Since it is nearly a sphere, you can use its diameter to calculate its circumference (c = pd) and come up with something close to 25,000 miles. We don’t know what the earth is mostly made of because we have never experienced much of anything more than a few miles beneath its surface. However, there are a few things that we know about its insides. When the earth cracks, molten rock comes out. This means there are some super hot spots in there, and probably a lot of rock. Rocks are large hunks of dense crystalline mineral material thought to have been formed by the cooling of the original components of the earth.

Most scientists believe the earth is hottest near the center. Rock melts to become magma when it reaches something close to 2,000°C. Water in the deep ocean is sometimes carried below the ocean floor where it is superheated under pressure. This water then comes blasting out of the earth at temperatures that may be several times the boiling point of water. When it comes out it carries dissolved minerals from deep inside the earth. By studying this water, we can learn a little more about the chemistry of the deeper earth.

The earth is thought to be composed of three internal layers: (1) an inner core of magnetic metal surrounded by magma which was formed from molten core material, (2) a thick mantle of dense crystalline rock surrounding the core, and (3) a thin (but not light and flaky) crust.

We are much more familiar with the crust than with the deeper earth. It is approximately 15 miles thick, although its thickness varies from place to place, and it contains all of the earth’s oceans, rivers and streams. It also contains the mountains, plains, valleys, ridges and plateaus. It is made up of layers of rock, sediment (settled material) and soil. (Later, we will define soil and talk about it in detail.) Although we think of the oceans as several in number (Indian, Arctic, Atlantic, Pacific), they are actually one continuous body of water. We might refer to it as “the ocean” rather than as the oceans of the world. The ocean bottom is covered with geological formations that appear similar to the mountain ranges, valleys, plains and other surface features of the land. It also has deep cracks, called trenches, that form the ocean’s greatest depths. The greatest depth is in the Mariana Trench which is in the western Pacific basin. Nobody has ever reached the bottom of the trench at the location of its greatest depth, approximately 6.8 miles beneath the ocean’s surface.

The bottom of the ocean is covered with sediments containing living things and the remnants of life (such as dead animal and plant matter) that settle down from the water above. Much of the deep ocean is largely unexplored because of the difficulty involved with such extreme conditions. It is mostly cold (averaging about 1°C) and dark (sunlight is unable to penetrate that much water), and the weight of the water at the bottom is crushing to all but the most sturdily crafted vessels and animals designed for deep-ocean survival. At the ocean’s greatest depths, the water pressure is as high as 8 tons per square inch.

Dry land is composed of layers of soil that lie atop solid rock. Although nobody saw it happen, most geologists presume that soil formed by the wearing away, or erosion, of rock. Erosion is what happens when wind and water cause particles to grind against each other, reducing larger particles into smaller ones. Those small particles are carried away by wind or water, and tend to collect in low-lying areas. Freezing and thawing cycles are also thought to play a part in soil formation by causing large rocks to fracture into smaller ones. Living things, especially bacteria, are believed to help this process along by producing acids that seep into the minerals of rocks and dissolve them, weakening the rocks’ structures.

People who rely strictly upon physical processes to explain the earth’s existence determine that it has taken billions of years to arrive at the earth’s present condition from what it is believed to have been in the past. We who believe in the Creator are not restricted to this model for the explanation of what we see. Today, most of us maintain that the age of the earth is not known with any degree of certainty. We have no doubt that the Genesis account of creation, although not intended to be “scientific” (because it was written before scientific method was developed), is the best representation of how the earth came into existence that could be devised to be understood and believed across time and nations. This account has been accepted by a great many people in every generation since it was written 3500 years ago.

But the Genesis writings do not teach us the technical detail of the earth. Scientists want to know this information so we can use it for understanding and predicting. For this reason we investigate, trying to understand the actual ways in which the earth (and, indeed, the universe) was formed.