“I think that we shall have to get accustomed to the idea that we must not look upon science as a 'body of knowledge', but rather as a system of hypotheses; that is to say, as a system of guesses or anticipations which in principle cannot be justified, but with which we work as long as they stand up to tests, and of which we are never justified in saying that we know they are 'true' or 'more or less certain' or even 'probable'.“
— Karl Raimund Popper
The Logic of Scientific Discovery (1959), 317.
Scientific method
Recently a question about gravity was posed on our Wiki site, and since I did not know what the answer to the question was, I thought that this would be a good time to do some research together. To put us on the right track toward our answer we are going to look at the method that scientists use to answer questions about the universe around us. That method is called the scientific method and it consists of 7 discrete steps on the way to an answer. The definition of scientific method from the Merriam-Webster online dictionary is: “the principles and procedures for the systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of hypotheses.” The 7 steps of scientific method are: ask a question, do background research, construct a hypothesis, test your hypothesis by doing an experiment, analyze your data and draw a conclusion, and finally, communicate your results. So in order for us to find an answer our question we need to follow the steps just like a scientist would do.
The very first step is to ask a question which has already been done. Excellent job! The question that was asked is: “If we were able to drill a hole right through the Earth and then jumped into the hole, would we begin to slow down as we reached the center of the Earth since the mass "above" us would equal the mass "below" and would cancel out gravity? “ So just to rephrase the question a bit: Does the force of gravity decrease as an object nears the center of our planet?
Now that we have the question identified it is time to begin researching the question using all sorts of journals, textbooks, magazines and web sites. The goal is to become as knowledgeable on the subject as it is possible to become. I think you are beginning to notice that answering these questions can take a lot of time aren’t you? As we read we will take written notes, (in our Science Notebooks of course!) about what we read and where we read it so that we can refer back to the article in the future. The more research we do, the more knowledgeable we will become on our question.
The next step is to construct a hypothesis. A hypothesis is an educated guess about the answer to our original question. We are able to make that guess because of all the research that we did that made us experts on the subject matter. The hypothesis is usually written in a specific form "If _____ [I do this] _____, then _____ [this] _____ will happen." Another requirement for a hypothesis is that it should be something that you can actually test. Those tests are important because we need to measure both "what you do" and "what will happen."
Now that we have done all of this work and we have our hypothesis that has been so carefully crafted all we need to do is answer the question, right? We still have a few more steps to go yet! Now we need to actually test our hypothesis in an experiment that we design. A good experiment has some characteristics that are important to our science discoveries, they need to be narrowly focused (only one Independent Variable…you can look it up for extra credit!), repeatable, and able to be measured. Once we have designed our experiment and ran it once, we need to repeat it at least twice more in order to verify the results. Once we have collected all the data from our experiments, then we can begin the next step of the scientific process and that is to analyze the data that we have gathered.
“It is a common failing–and one that I have myself suffered from–to fall in love with a hypothesis and to be unwilling to take no for an answer. A love affair with a pet hypothesis can waste years of precious time. There is very often no finally decisive yes, though quite often there can be a decisive no.”
Advice to a Young Scientist (1979), 73.
All that data from all of those elegant experiments we designed and conducted and now we come to the really fun part of our process, we can, at last, draw a conclusion from all of our work. Sometimes it might be an answer we expected and one that proves our hypothesis, but equally important the answer might prove our hypothesis wrong. How could that be good you might ask? Even if our hypothesis is proven wrong we have a “real” scientifically tested, answer that we can build our inquiries off of when we go back to the earlier stages of the process to begin to build a new hypothesis. This cycle of design and test is the basis of all scientific method and the key to our inquiries of the universe.
Finally we have an answer to our question and we know the truth. The answer has been tested and repeated and the experiments have even been done at other labs. The final stage in the scientific method is to share our results with science. Real scientists do this all the time when they publish their scholarly work in prestigious scientific journals. We can publish also thanks to the Internet! There are all sorts of Websites devoted to science and once we have our answer we can post our results for everyone to read…and yes, to question, because that is the true nature of science, to study, to learn and to teach.