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Sample Lessons for The Rainbow Year 1
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The Rainbow
Red Section
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.
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?
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
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.
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 _________________.
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
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.
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?
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).
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.
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.
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.