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Home | Contents | 1-3 Science | 4.1 Experiments | 4.2 Units | 4.3 Measurement | 4.4 Safety | 5 Data | 6-7 Reports | 8 Appendix

VCS Science Handbook Sections 1-3

1.0.0 Introduction

  • The purpose of this handbook is to make clear to students of all abilities and interests in science some of the basic methods and procedures that scientists use to discover and communicate knowledge about the world. Because of the many topics covered in this handbook (such as designing experiments, converting units, and drawing graphs), each topic is covered only minimally. If you need clarification or more examples of a concept or method, then ask your science teacher. After all, science begins with questions!

2.0.0 What is science?

  • 2.1.0 Definition: Science is a field of study that typically makes use of some type of scientific method to answer questions about the world, test hypotheses, and form explanations of naturally occurring events.

  • 2.2.0 What science is not:

    • 2.2.1 While science seeks to obtain useful knowledge about the world, it is not the only discipline that does so. In fact, it is not the only field of study that uses scientific methodology; history, theology, and philosophy also use some type of scientific method from time to time. Therefore, it is proper to regard science as one (not the only) way to obtain reliable knowledge about the world.

    • 2.2.2 Science cannot be defined in such a way as to rule out religious considerations (such as Creationism) without also eliminating parts of science. In other words, there is no way to define science such that the definition includes all science and only science.

    • 2.2.3 Science is not a study isolated from all others. For instance, it depends upon and frequently interacts with philosophy. Theology, mathematics, history, and other fields can also interact with science.

3.0.0 Scientific Methods

  • Defining and describing scientific methods is difficult for several reasons. One reason is that there is not one scientific method that all scientists follow (which is why you will not see the phrase “the scientific method” in this handbook). Another reason is that different philosophical views of science define scientific methods differently, and some views even state that there is no such thing as a scientific method!
  • Despite these difficulties, we can still describe some of the things that many scientists often do to solve scientific problems.
  • 3.1.0 Observing and stating a problem

    • Scientists often begin their research by observing something in nature that does not have a satisfactory explanation. This problem can frequently be stated as a what, when, why, where, or how question.

    • For instance, someone trying to answer the question of whether life might have existed on Mars could observe that the planet would have needed liquid water to support life and then ask the question “What amount of water did Mars have on its surface?” The person might also ask, “Where did the water go?” or “When was the last time that the planet had liquid water?”

  • 3.2.0 Forming a hypothesis

    • Next, the scientist could form some educated guesses or possible explanations, called hypotheses (singular: hypothesis), about the answer to the observed problem. Sometimes, well-established theories predict certain facts about the world, and those predictions can be considered hypotheses, too. Hypotheses are often stated in an “If…then…” format.

    • For example, a scientist could say, “If there was enough water on Mars to form streams or rivers, then we should find evidence of erosion such as gullies and canyons. We should also find evidence of material carried by water such as that in dry lake beds and river sediments.”

  • 3.3.0 Testing the hypothesis

    • One of the most important and difficult parts of scientific research is testing hypotheses. This testing usually comes in the form of experimentation but can also come in the form of observations. Experiments are tests that are usually done in the laboratory under carefully controlled conditions. During experiments, researchers usually record numerical data (singular: datum), facts about the experiment they are doing. For more information about experimentation, refer to section III of this Handbook.

    • In the case of the Mars water hypothesis, testing is a bit more difficult than it would be here on Earth because humans have not been to Mars. Most tests of the hypothesis would involve observation, either by orbiting spacecraft or by rovers such as Spirit and Opportunity. Observations could include detailed photographs of canyons from orbit or close-up images of sand grains and minerals from a rover. An example of just such an image is shown in Figure 1.

    • handbook-mars_water-640.jpg
    • Figure 1 Two images of the inside of a crater on Mars photographed six years apart by the Mars Global Surveyor. Note the new deposit at lower right.
    • Courtesy NASA/JPL-Caltech

  • 3.4.0 Analyzing and concluding

    • Both during and after collecting data from an experiment or observations, scientists analyze the data, which often involves looking for familiar patterns or interpreting new patterns. Scientists then draw conclusions from the data, such as whether their hypothesis is supported by the data or whether a particular theory is shown to be false in some way. While scientists usually do their best to be objective, their own biases (such as their expectations of what will happen in an experiment) sometimes influence their conclusions. Therefore, analyzing and concluding is not always easy, and many arguments arise among many scientists about how best to interpret experiments and their data.

    • The photographs in Figure 1 show that a new deposit formed on the inside of a crater on Mars within the past few years. How should that observation be interpreted? Some scientists believe it is evidence that liquid water forms on Mars even today. Others might interpret it as a rockslide that turned up some new soil or as the effect of wind. To decide between those ideas, comparisons can be made to similar events that happen on Earth. For the person suggesting that the new deposit was formed by flowing water, new questions arise, each of which is a new problem to be solved. Examples include, “How did the water get on the side of the crater? Is there a seasonal stream somewhere? Did it come from underground?” “Where is the water now? Is it at the bottom of the crater, in the ground, in the air, or frozen in place?” and “What conditions on the surface or underground allow the water to form?” The answers to these questions and others would help scientists know whether Mars was ever capable of supporting life.

  • 3.5.0 Communicating results

    • When scientists make discoveries, they usually write an article and submit it to scientific journals for publication. Publishing work gives other scientists the opportunity to learn information that can help with their own research or inspire new hypotheses, and it provides news media opportunities to announce important findings to the general public. Some journals (like Nature and Science) are very broad in the topics they publish, while others (like Blood) are very specific. Before an article is published, other scientists read the article first to make sure it is worthy of publication. This is called peer-review, and it is a way to ensure that scientists explain their work clearly and that their research has merit. In science classes, you might be required to type a formal lab report to communicate findings from a laboratory experiment.

    • The discovery of new deposits in craters on Mars was published in the journal Science in December 2006, causing excitement among Mars researchers and enthusiasts. The reference of the article is as follows:
      • Malin, M. C., Edgett, K. S., Posiolova, L. V., McColley, S. M. & Noe Dobrea, E. Z. (2006). Present-day impact cratering rate and contemporary gully activity on Mars. Science, 314(5805), 1573.

    • Here is a short description of the article:
      • Images of Mars taken 7 years apart reveal 20 new impact craters, close to the predicted rate, some with gullies indicating the presence of flowing water in the past decade.

  • 3.6.0 Forming a theory

    • Like the term “science,” “theory” is difficult to define due to a variety of existing viewpoints. One common interpretation is that theories offer explanations of natural processes by making models of the systems in question. In this view, a law is simply a description of observed occurrences.

    • For example, Gregor Mendel discovered the laws of heredity (that certain crosses produced certain outcomes) around 1865, but a theory of genetics involving chromosomes, genes, cell division, etc. that thoroughly explained the laws of heredity did not arrive for nearly fifty more years. Theories usually come from many observations and experiments from many scientists; Gregor Mendel had to communicate his results before other scientists could form theories of genetics.

    • Some scientists and philosophers believe that a good theory is one that makes true or approximately true statements about the world, while others believe that a good theory is one that is simple, self-consistent, matches observations, makes accurate predictions, and guides new research (Moreland, J.P. (1989). Christianity and the Nature of Science.).

    • As to the question of water on Mars, it seems that many of the proposed answers are still hypothetical (uncertain). Hopefully, as Mars is further explored and more data is obtained, scientists will be able to work out good theories of Mars’ geologic history, including the role of water in shaping its surface and possibly supporting life.