The Methods of Science Chapter 1

What is science? Science is a method for studying the natural world. It is a process that uses observation, investigation, and pattern discovery to gain knowledge about events in nature.

3 Major Categories of Science Life Science This deals with living things Ex: Biology Earth Science This deals with Earth and space. Ex: Earth Science and Astronomy Physical Science This deals with matter and energy. Ex: Chemistry and Physics

Even though we try to separate the sciences into main categories, sometimes these categories overlap. An example would be a scientist who may study the motions of the human body in order to build better, more realistic artificial limbs.

Physical Science Chemistry- the study of what matter is made of and the changes in matter. Ex: atoms, elements, solutions, acids, etc. Physics- the study of how matter and energy are related. Ex: motion, electricity, magnetism, gravity, sound, heat, light, etc.

Scientific Methods When scientists have an investigation they want to do they follow a general pattern usually referred to as a scientific method. Scientific method is an organized set of investigation procedures. There is more than one type of method used by scientists.

6 Common Steps in Scientific Methods: 1. Stating a problem or observation 2. Research and gathering information 3. Forming a hypothesis 4. Testing a hypothesis 5. Analyze data 6. Draw conclusions.

1. Stating a Problem or Observation: Many scientific investigations begin when someone observes an event in nature and wonders why or how it occurs. Sometimes a statement of a problem arises from an activity that is not working. The question of “why” or “how” is the problem

2. Researching and Gathering Information: This is when we would learn about the history and background behind a hypothesis or a proposed problem. This is useful for narrowing down what to test and how to test it.

3. Forming a Hypothesis A hypothesis is a testable prediction. A good hypothesis includes an explanation and a prediction Ex 1: Homing pigeons use their ears to find their way home. If their ears are covered up, they will lose their direction Ex 2: Studying my notes improves my test score. If I study, I will score higher on my test.

4. Testing a Hypothesis aka Experiment: Some hypotheses can be tested by making observations, others can be tested by building models and relating it to real-life situations. Many hypothesis will be tested by designing an experiment. An experiment tests the effect of one thing on another using controlled conditions.

Experiments usually contain at least two variables. A variable is the factor or thing being tested. There are two types of variables: Dependent variable, the variable that will change as you manipulate the experiment. Independent variable, the variable that you change in order to manipulate the dependent variable.

Experiments will also use constants and controls. A constant is the factor that does not change when other variables change. A control is the standard by which the test results can be compared.

Sometimes while doing an experiment you will see or hear experimental group and control group The experimental group is the group that receives the independent variable. The control group is the group that does NOT receive the treatment or independent variable.

5. Analyzing the Data: An important part of every experiment includes recording observations and organizing the test data into easy to read tables and graphs. When you are making and recording observations you should include all results, even unexpected ones. If the data is not organized in a logical manner the wrong conclusion may be drawn. All scientists share their data through reports and conferences so that more than one person can have an access to the data.

6. Drawing Conclusions This is where you look at your data and determine if the hypothesis was supported or not. For an experiment to be considered valid and widely accepted, it must result in the same data every time it is repeated. If your hypothesis is not supported use the data to reconsider your experiment and hypothesis.

It is important to remember to be objective when coming to conclusions. A bias occurs when what the scientist expects changes how the results are viewed. This may cause the scientist to ignore results in favor of the ones that support the desired outcome.

To eliminate this bias, scientists run as many trials as possible. They also keep very accurate notes of each observation made. The experiment MUST be repeatable by anyone. Findings are supportable when others perform the same experiment and get the same results.

Visualizing with Models Sometimes a scientist cannot see every thing they are testing, so they create models to help them. Models represent an idea, event, or object to help people better understand it. They have been used frequently in history.

Lord Kelving, a scientist who lived in England in the 1800’s, was famous for his models. He put balls in a bowl of jelly and hand people move them around with their hands in order to demonstrate his idea of how light moves through space.

With today technology we can make different types of models. We can program a computer to build and run through a model while we change different variables to determine the out come. NASA uses computer models to calculate it’s equations for them. This speeds the process up.

Scientific Theories and Laws A scientific theory is an explanation of things or events based on knowledge gained from many observations and investigations. Scientific Law is a statement about what happens in nature and that seems to be true all of the time. Ex: Law of Gravity

Limitations of Science Science cannot explain or solve everything. Things like emotions and morals cannot be tested.

Technology Technology is the application of science. It doesn’t always follow science however. When the steam engine was invented the inventors had little idea has to how it actually worked. This problem intrigued scientists like Kelvin, Joule, and Carnot; who helped explain how the steam engine works and furthered our understanding of physics.

Technology does not always produce positive results. For example nuclear technology and genetic engineering were two things that science helped develop. Currently these are subjects of debate among society. Being more knowledgeable about science can help us address these issues as they arise.