Ultimately, the purpose of your involvement in this class is to learn about the science of the Earth. Along the way, I hope you'll gain a degree of scientific literacy as well as increase your critical-thinking skills. With a little effort on your part, increased scientific literacy can be easily acquired during the semester. The purpose of this primer is to acquaint you with some basic concepts in science -- to give your geoscience literacy a "jump-start." Scientific literacy involves learning what science is, what scientists do, what they know, and how they know it. Below you'll find out a bit about each of these topics and about how we'll approach learning more. Acquiring critical-thinking skills is a much more challenging task and one that we'll work on all semester long.

The remainder of this document is linked to the 10 questions below so that you can more easily read through the document at your convenience. Read through each section in order and stop at any time.  When you come back the color of the hypertext links will serve as a bookmark to indicate what sections you still need to read.

1. What is science?

2. What do earth scientists do?

3. How do scientists do science?

4. Facts, information, and knowledge: how do they differ?

5. Why isn't science always right?

6. If science is so complicated, how can we possibly begin  to understand it?

7. What are the conceptual foundations of earth science?

8. Since earth science is not merely temporal, but also spatial and therefore visual, how are visual concepts represented?

9. I believe, based on what I've learned in church, that the earth is only 6000 years old.  Why should I believe any different?

10. What's next?

What is science?

Science is a way of looking at the world and trying to understand its materials and processes. Religion is another way of doing this, as is philosophy. Science is also a body of knowledge acquired in a particular way. Not everyone agrees as to how science should be defined, so some folks say "science is what scientists do." However, one aspect of science is clear: the scientific approach to understanding the world is materialistic, that is, it relies only on natural forces for its explanations. Unlike religion and philosophy, science does not consider or recognize supernatural forces.

Although many people don't know it, science is fundamentally different from engineering and technology, as well. Engineering is a method for approaching and solving problems: how to construct an earthquake resistant bridge, design battery-powered cars, or build lighter laptop computers.

 Science often involves engineering and vice versa, but they are not one in the same. The scientist's approach to understanding materials and processes is known as the scientific method (discussed below). Engineers may use the scientific method, but more commonly they simply use trial and error.  Scientists use engineering to explore the world more fully. Engineers use scientific discoveries to develop new solutions to problems. Technology is the implementation of these solutions.

For example, let's assume a chemist performs scientific research to develop an alternative to nitroglycerin as an explosive for mining. While doing so, she discovers a particular compound that is too unstable to use in mining, but would make a good jet fuel. After she publishes her research results, a chemical engineer devotes several years to developing the proper ratio of fuel to oxygen for a variety of engines. Then mechanical engineers decide to develop a new jet engine especially for this fuel. Finally, other engineers prepare production facilities for manufacturing the fuel and engine. The final result -- a new, faster jet engine representing advancements in jet fuel and engine technology -- would be the end product of a multi-year collaboration between science, engineering, and technology.

What do earth scientists do?

There are, of course, many different disciplines within earth science. Typically, earth science consists of three broad areas: geology, oceanography, and meteorology (some would add astronomy). Each of these areas is subdivided into several subdisciplines. These subdisciplines, such as geophysics, geochemistry, and climatology, take a variety of approaches to studying the Earth. Some are predictive while others are more descriptive. Still others are historical. Predictive sciences allow us to better understand the world and predict how it will behave. Descriptive sciences merely provide details about how the world works or looks or of what it is made. An historical science interprets the events of the past in order to develop a time-line, or chronological sequence.

Besides these broad divisions there are still more ways to subdivide or categorize the earth sciences. Sciences are mathematical or narrative. A mathematical science describes the world numerically using equations, whereas a narrative science does so verbally. Mathematical sciences are often called quantitative. Narrative sciences are termed qualitative. No science is purely mathematical or narrative, rather they all lie somewhere in between.

Sciences can also be classified as observational or empirical. Observational science involves simply evaluating naturally-occurring processes and interpreting their significance. Empirical science requires the development of experiments, often to isolate or re-create an activity so that it can be more easily studied.

Earth science is a broad field consisting of sub-disciplines that together occupy all of these categories: predictive, descriptive, historical, mathematical, narrative, observational and empirical. As GEOL-100 is an introductory course, we will usually take an approach that is predominantly descriptive, narrative, and observational. However, we will sometimes approach things from a perspective that is historical, predictive, or even mathematical.

How do scientists do science?

No matter what science someone practices, all good scientists have things in common. Every scientist routinely applies critical-thinking to his or her research. They all evaluate the quality of their data and interpret its meaning, and attempt to find alternative explanations for their findings. And they seek input from other experts in their field concerning the quality and significance of their interpretations. As a rule, scientists use an investigative technique known as the scientific method -- a time-honored approach to critical-thinking.

Much has been said and written about the strengths and weaknesses of the scientific method, but it is clearly the best investigative approach devised to date. It consists of a sequence of steps, some of which must be repeated numerous times during the development of a new or revised theory.

The initial step in the scientific method always involves identifying the question to be answered. This can be, for example, the result of observations of nature, idle curiosity, brainstorming, or previous research. After the point of interest is identified, a hypothesis must be developed. Sometimes this can be done immediately, but many times further observation is needed.

The hypothesis must be stated in such a way that it is clearly defined and readily falsifiable. To be falsifiable, a hypothesis must be capable of being disproved. For example, the statement "I am the reincarnation of the moon!" may sound absurd, but it's not falsifiable. That is, we cannot disprove this statement. On the other hand, the statement "I am the reincarnation of the moon and therefore made of cheese!" definitely sounds absurd and is falsifiable. We can easily prove or disprove this statement. Therefore it is a testable hypothesis.

Ideally, all investigators should use the method of multiple working hypotheses in testing their data. This method requires that the researcher examine his or her data using multiple hypotheses rather than just their favorite. This should discourage bias toward a particular outcome. Most experienced researchers probably employ this method, even if only subconsciously. In practice, however, this is often time-consuming, expensive, or difficult to formally implement. In addition, today there are rarely any researchers who are working alone in their field. Therefore, other scientists can usually be counted on to provide this service (see peer review below).

Another important concept that should always be applied to research is parsimony. Parsimony states that the best hypothesis is usually the simplest one that explains all the available data. Hypotheses that are unnecessarily complex are more likely to be wrong. Parsimony  is also known as Ockham's razor in honor of the fourteenth century philosopher William Ockham. He stated this concept as "entities should not be multiplied unnecessarily'".

After developing a testable hypothesis, it must be tested either through experimentation or further observation -- a.k.a. data collection. The scientist then interprets the data and tests the hypothesis. If it is false, then the scientist revises and retests the hypothesis or discards it. If the hypothesis is not falsified, then further testing will occur.

Let's assume that after numerous repetitions the hypothesis still holds up under scrutiny. Then the researcher approaches colleagues and asks them to test his or her findings, or publishes the results so others can try to reproduce his or her work. This process is known aspeer-review. It is the backbone of all sciences. The original researcher must provide any and all interested parties with the full details of his or her work so that review, scrutiny, and criticism occur. Only in this way can we hope to advance the frontiers of science. All scientific findings must see the light of day and withstand harsh criticism from supporters of opposing ideas.

Hypotheses that emerge from peer-review unscathed and have been thoroughly tested by a variety of researchers will eventually be elevated to the level of a theory. Contrary to popular belief, theories are not simply educated guesses. They have been extensively tested and peer reviewed, and often revised, and they agree with all known findings and observations. In other words, theories have never been falsified. They are the end product of thousands of hours of work performed by experts under the scrutiny of competing researchers, some of whom, at least at first, wanted them to fail. No better system exists anywhere for the testing and validation of ideas. Organic evolution and plate tectonics are examples of theories that are accepted almost unanimously by scientists in all the nations of the world.

Theories that have been around for centuries, have never been successfully challenged (falsified) and which are simple enough concepts that they can be concisely stated (especially as an equation) are called laws. Laws generally have broad application in the world and so are being regularly tested indirectly. A good example is the law of gravity. Every time you take a step, throw a ball, or drop a pencil you test this law.

Laws are as close as science gets to the truth. In general, science is not the absolute last word on anything, but rather the best available explanation based on current data. You should be leery of anyone who says that they can "prove" this or that. Scientists usually talk in terms like "indicates," "suggests," "supports," or "verifies" but not "proves." They also "provide evidence for," but don't "uncover the truth." Truth is really a value judgment -- something that most scientists tend to avoid in their professional activities.

Facts, information, and knowledge: how do they differ?

There are a few other things you should probably know about scientific outcomes. Generally, the unbiased, uninterpreted products of observation and experimentation are called data or facts. These are considered facts because they are objective data rather than subjective opinion. For example, "this rainwater has a pH of 4.5" or "this rainwater contains 356 parts per thousand of sulfate." Once that data is organized and interpreted it is then information or an outcome. For example, "this rainwater has been polluted by sulfur emissions." Information that has been verified and peer reviewed is knowledge. However, knowledge is only as accurate as the data and interpretations on which it is based. Therefore all knowledge is subject to revision and correction, particularly when researchers collect or interpret data using newly developed techniques or ideas.

Why isn't science always right?

It's not clear when or why the idea that science should be infallible came about, but it really doesn't make much sense. Scientists are just normal people using ordinary logic and reasoning to learn about the world. Why should they be expected to be free of all the frailties and shortcomings that everyone else possesses? The successes that science has achieved are really a product of three things: the superiority of the scientific method as a way of arriving at well-reasoned answers to questions, the use of superior equipment and technology, and reliance on the accumulated knowledge of past researchers. Without these, science would be no better than educated guessing and idle speculation.

You may be one of the many people who believe that science isn't all its cracked up to be since scientists are constantly bickering and changing their minds. On the contrary, scientists know that therein lies the real strength of science. Some would even say that science is never "right," and a scientific theory is never complete, but rather it is always undergoing improvement. Science isn't dogma, it is instead a system of trial and error that is constantly upgrading its findings. Revision of a theory doesn't mean it was totally wrong, only that it wasn't totally right.

The complexity of earth systems is one of several reasons why theories often need regular revision. When "doing" science, earth scientists often apply the system concept. A system is a group of interrelated and interdependent processes and products that together form an interactive unit. There was a time when scientists didn't recognize the complexity of systems or the importance of the interactions between their components. So, in many ways, scientists missed seeing the forest for the trees. Now the approach taken by researchers is more interdisciplinary in recognition of the complexity of many earth systems. For example, a study of the climatic effects of volcanic eruptions may involve geologists, meteorologists, climatologists, oceanographers, geochemists and geophysicists.

The unrecognized influences of chaos also drive the revision of scientific findings. Chaos theory is based on the concept that minor changes in a system can eventually lead to very significant changes in the behavior of that system. Since these small perturbations can be hard to detect much less predict, they make it very difficult to understand the behavior of the system. Chaos is what makes it so difficult to accurately forecast weather more than a day or two in advance.

Yet another challenge to the accuracy and permanence of theories in earth science is feedback. A feedback occurs when a change to a system triggers a sequence of changes which either reinforce or nullify the initial change. A positive feedback reinforces the initial change. For example, colder temperatures might cause less snowmelt at middle and high latitudes. Increased snow cover would reflect back more sunlight, and the earth would become colder. A negative feedback counters the initial change. For example, higher temperatures might cause greater evaporation. This could lead to more cloud cover and so less heating at the surface, and temperatures would decrease. Within systems, recognition of feedback "loops" and determination of the net effect of multiple feedback loops are significant challenges to modern science.

Perhaps the most subtle challenge to earth scientists is the occurrence of dynamic equilibrium. Dynamic equilibrium involves a delicate balance between the inputs to and outputs from a system -- with respect to both materials and energy. A system operating under dynamic equilibrium tends to maintain a steady state with only minor changes in the system, but it is not totally static. Accounting for all the various controls that combine to maintain this balance is, at the very least, difficult, and it may be impossible for some systems.

If science is so complicated, how can we possibly begin to understand it?

Some people who take this class arrive full of apprehension, having already decided that earth science is beyond their abilities. Have no fear. I don't expect you to earn a Ph.D. in meteorology, I just want you to learn a little earth science and to apply that knowledge to some novel situations. When we learn some science, unless we are specialists in that field, we usually learn a watered-down version that is simpler and, therefore, easier to understand. Typically, we learn by using models, analogies, and generalizations.

Models are simplified representations of systems, processes, concepts, or designs, developed in order to allow study, or to improve understanding. All models are tools for thinking -- they help you learn by providing information in smaller chunks or simpler ways. You are surely familiar with physical (scale) models of cars and buildings. Books are verbal models, whereas diagrams are graphical models. A calculator is a type of computer model used to solve equations, while equations are mathematical models of natural phenomena. Perhaps the most important type of model is the conceptual model, such as the model of earth science you're now constructing in your mind. Throughout this course you should steadily revise and improve this conceptual model.

The term paradigm lately is used as a synonym for "model." We will use this term in a more restricted, but grander sense -- as a far-reaching, pivotal theory that acts as a foundation for one or more branches of science. Every science has it own paradigm that serves as a theoretical framework upon which other ideas build. In biology, this is the theory of organic evolution. In geology, plate tectonics is the prevailing paradigm and has been for the last twenty-five years or so. When an area of science undergoes a radical change in the nature of its paradigm -- as geology did in the 1960's -- it is said to experience a paradigm shift.

Although you may not know it, you regularly use analogies to communicate with others -- in other words, to "teach" them what you're thinking. An analogy is simply a comparison between two things which have something in common. These include, for example, concepts, materials, processes, and situations which share a common origin, structure, or outcome. The purpose of using one concept as an analog for another is usually to better explain something unfamiliar by comparing it to something familiar. For example, we might use squeezing a tube of toothpaste as an analogy for an erupting volcano. However, you must always remember that it is only that -- an analogy -- and no analogy is perfect. An analogy is an aid for learning, not a substitute for it.

Generalizations are commonly used to avoid getting bogged-down in details and exceptions. Rather than deal with very precise and exacting concepts, we make a few assumptions that help simplify things. This approach, often referred to as using first principles or a first approximation, allows us to grasp the basic concept without drowning in details. In the early stages of learning a science, we can adopt the attitude that as long as we end up with an answer that is in the ballpark we learned something along the way. Scientists often take this approach when studying new or particularly difficult subjects. They might accept an outcome provided that their assumptions lead to an answer that is within perhaps an order of magnitude (1/10 or 10 times) of the correct answer.

For example, while trying to determine the number of sand grains on a beach, you may make certain assumptions about the sand's volume, weight, packing, water content, etc., etc. Based on these assumptions, you might be comfortable with the answer 300 billion grains, while actually knowing that it could be 30 billion or 3,000 billion. In other words, you might be an order of magnitude off either way, but for a first approximation, it's not bad! Hopefully your estimate would not be off by two orders of magnitude:1/100 or  100 times. If so, the number of sand grains would be more like 3 billion or 30,000 billion (30 trillion!).

What are the conceptual foundations of earth science?

Every mental discipline has its own conceptual foundations -- fundamental principles that form the basis of all other concepts. As earth science is actually a collection of sciences that developed independently, these principles are numerous. Some may be unique to earth science, others are not. I will only touch on the most basic and necessary here. You should quickly become fluent with them as they are pervasive in this course.

All earth sciences use the concept of cycles. A cycle is a system through which matter and energy move in a series of steps usually with multiple available process and product pathways. The hydrologic cycle is probably the most widely recognized example of an earth cycle. A single drop of rain can follow several different process pathways: evaporation, run-off, infiltration, etc. Following condensation, there are also many available product pathways: hail, sleet, rain, snow, etc. Incidentally, a cycle is another example of a conceptual model.

Classifications are also ubiquitous in the earth sciences. We classify clouds, minerals, rocks, precipitation, volcanoes, etc. All such classifications can themselves be classified as either genetic or empirical. That is, either relating to origin, or to physical characteristics. For example, rocks can be classified according to how they form (their genesis) or according to one or more physical (testable, or empirical) traits.

Earth science is a physical science.  Like all sciences that measure characteristics of the physical environment, earth science uses the elementary concepts of density, pressure, direct and inverse relationships, and gradients.

Density is a measure of weight per unit volume (for example, lbs/ft³); in other words, a way of expressing how closely matter is spaced  within a substance. Although not an easy concept to grasp, density, along with gravity, is responsible for the weight of all substances. For any substance, the greater its density, the more it will weigh under an equal pull of gravity. Specific gravity, used by geologists, expresses density as a ratio of the weight of a specific volume of a substance to an equal volume of water. The specific gravity of water is, of course, 1.0, table salt is 2.1, and gold is 16.7. That means a cubic inch, or a cubic foot, or a cubic yard of gold weighs 16.7 times the same volume of water. A low specific gravity indicates that a substance has a low density, and a substance with a high specific gravity has a high density.

Pressure is the force exerted on a molecule by other, surrounding molecules. For example, the pressure increases on your ears when you dive below the surface of a pool due to the weight of the overlying water. For all substances, as pressure increases density increases. This is called a direct relationship. Conversely, in an inverse relationship, when one factor increases the other decreases (or vice versa). For example, as the pressure on a substance increases its volume decreases.

A gradient exists when matter or energy is unevenly distributed within a system. As long as sufficient energy is available, nature will always act to redistribute matter or energy from areas of higher concentration to areas of lower concentration. For example, this is why, when one end of an iron rod is placed over a fire, heat will travel from the heated end to the cool end. As another example, a pressure gradient is why the wind blows. Wind blows from areas of higher air pressure (molecule density) toward areas of lower air pressure.

The goal of geology is to interpret the history of the earth. Being an historical science, several concepts in geology are temporal; that is, they concern time. Uniformitarianism is crucial to geologic interpretation. A simple translation for this concept is "the present is the key to the past." Assuming that earth processes are uniformitarian, we can use modern, observable processes as models for ancient ones. For example, we can study modern river floods and their deposits in order to recognize and understand ancient flood deposits. This concept has tremendous power and versatility when used to interpret the events of the past. There is just one caveat: although the processes are probably the same, the rates at which they operate change with time.

Another facet of uniformitarianism is gradualism vs. catastrophism. Early geologists subscribed to the doctrine of catastrophism, with the biblical flood perhaps being the mechanism for all sedimentary deposits. The basic idea was that all earth's features formed during one or more catastrophic events of divine origin. This is a non-uniformitarian view of the earth which still survives today, only slightly altered, among adherents to the pseudoscience known as "creation science." By the 18th century, many geologists adopted a uniformitarian perspective now referred to as gradualism. They viewed earth features as a product of every-day processes acting gradually over immense spans of time. Suddenly the earth was not thousands of years old, but rather millions -- a concept inconceivable to many people and contrary to the doctrines of some religions.

Today, we know the earth is billions of years old. But we also now know that a gradualistic view of the earth doesn't tell the whole story. Periodically, the earth experiences large-scale, highly destructive events (such as asteroid impacts) that significantly affect earth's atmosphere, oceans, land surfaces, and life. Therefore, a new concept, often called neo-catastrophism recently arose. This concept implies that while much of geologic activity is gradual, these every-day processes may be less significant in shaping the earth and its environments than rare, large-scale, catastrophic events. However, once recognized and accounted for, periodic catastrophes can be considered uniformitarian. In other words, neo-catastrophism only requires that we revise the theory of uniformitarianism, not discard it. This new balance between a catastrophic perspective and a gradualistic one is termed actualism.

Looking at the earth's many physiographic features -- mountains, ocean deeps, coastlines, plateaus, and river valleys -- from a gradualistic perspective, you can easily recognize that geologic time is immense and, to a degree, incomprehensible. Therefore, some geologists refer to these vast spans of time as deep time. Keep in mind though, that meteorologists take an entirely different view of time, thinking rather in terms of minutes, hours, days, weeks, and months. Earth science, therefore, spans the whole spectrum of time.

Since earth science is not merely temporal, but also spatial and therefore visual, how are visual concepts represented?

To really appreciate earth science you have to see the many features of the earth, both large and small, and also relate them to the processes which formed them. We will approach this task from a variety of directions.

In class, as well as in your textbook, you will be treated to many photographs of landscape features. We'll make extensive use of a variety of graphs, maps, and tables to present data. You'll also be seeing lots of diagrammatic representations of features and processes from one of three perspectives: map view, cross-sectional view, and three dimensional (3-D) view.

Map, plan, or bird's-eye view is especially common in meteorology and is the same perspective as a road map. Cross-sectional, profile, or cut-away view is used extensively in earth science to show, for example, what is occurring below the earth's surface, within clouds, or under the sea. These views are combined in 3-D or block diagrams consisting of a front, side, and top view. When joined to form a block, you can get a better sense of what is happening in three dimensions.

I believe, based on what I've learned in church, that the earth is only 6000 years old. Why should I believe any different?

No one is suggesting that you have to change your belief system just because you're in this class. However, you are required to learn the material as taught and to acknowledge that the theories presented are the general consensus of scientific experts in those fields. Beyond that, you're welcome to believe any thing you want -- no matter how unconventional. You might, for example, believe that your deceased relatives were reincarnated and now live amongst the stars, or that the Earth is at the center of the universe, or even that the moon is made of green cheese -- it's all the same to me!

Well, you've made it all the way through the tour, so now what?

This is a good time to take a short break from studying. Then you should come back and review these concepts to cement them in your long-term memory, because you're going to need them throughout the course.

Each of the terms listed below is hyperlinked to its appearance in the text above. So if you need to refresh your memory, click away! To return to the term list, just hit your browser's <BACK> button. However, keep in mind that not all the concepts are thoroughly explained here.  If you need further information, look up the terms in a dictionary, an on-line encyclopedia, or your textbook.

You may also benefit from looking at the table of contents in your lecture guide. It will tell you where to find the material on study skills -- honing them a bit couldn't hurt.

Here's to good learning, good logic, and -- if that doesn't help -- good luck!