Source: Earth PD http://bit.ly/1ESoBKp Antigravity PD http://bit.ly/1zzUySX Weight CC http://bit.ly/1N8YqEE Fallen Ice Cream CC http://bit.ly/1DKz6iN Newton CC http://bit.ly/1zSAdJu Ptolemy PD http://bit.ly/1EaEL2Z Nuclear Plant CC http://bit.ly/1znUbeV
Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is science and the scientific process. So let's get started. We're going to talk about science itself, the scientific method, the difference between the laws and theories, and what scientific objectivity means.
Science is a process that humans use to understand their surroundings and how they work through testable experiments. It is a way of knowing how the natural world and our universe works. Science tries to do this by testing and explaining physical laws about the way the universe works.
In science, research is an important part of the process. And within it there are two main categories-- descriptive and experimental. Descriptive research is used to describe what is known about the world, such as measuring the average rise in feet of global sea levels over the past 100 years or observing and recording the distribution of a certain fish species population over 100 years in the Gulf of Mexico. Descriptive research is most useful for analyzing relationships occurring in the real world, but not for understanding causality.
Experimental research, however, is great for drawing conclusions about causality. It is usually in a controlled situation, which allows scientists to observe relationships and causes of effects. This type of research cannot fully represent reality in a controlled setting, which means that such experiments do not always provide realistic results of the way the world works. An example of experimental research would be testing what conditions allow a certain invasive species to thrive to understand what climates it could be a nuisance in, or experimenting on fish populations to understand what effects oil spills can have and what technologies might mitigate those negative impacts.
Both types of research are necessary and important forms of science. Each has its weakness. But they can often be complementary to each other. They help us understand the world around us and what factors are influencing how the world functions.
The scientific method is the foundation of science today and is made up of an iterative process of eight steps as follows. Observation-- scientists examine the way the world and universe around them works. Question formulation-- once a scientist has observed a particular phenomenon, they ask a question of that phenomenon, such as, why is the sky blue? Research-- scientists will research through libraries, internet, and peers to gather as much information about that particular phenomenon as they can to try to answer the question.
Next, scientists will formulate a hypothesis which addresses the question with a prediction about how the phenomenon works. Testing-- scientists will use experimentation and other methods to test their hypothesis and their question. Analysis-- scientists evaluate the data from their testing.
Conclusion-- based off of the collected data and information, scientists determine whether their hypothesis was rejected or supported by the results. Then the process is begin again, by themselves or other scientists, by beginning again at observation to create a reliable and thorough body of research on that particular phenomenon in an iterative process.
Let's break this down with a real world example. I watched a YouTube video about astronauts in space drinking water without gravity-- observation. Then I thought to myself, would two objects of different weight on Earth fall at the same speed if they were dropped from the same heigh-- question. Then I did some Google searching and discovered that there is a difference between mass and weight. Every bit of matter in space has a mass to it. But our weight is determined by the gravitational relationship between my mass and the Earth's, as well as our distance from each other-- research.
I predicted that the one with more weight would fall faster-- hypothesis. I went to the corner ice cream shop and bought a double scoop cone of ice cream. I walked outside and pulled out a paper clip. I held them out in front of me at the same height and dropped them-- testing.
I watched them both hit the ground at the same time-- analysis. I discovered that my hypothesis was wrong. Even though the ice cream had more weight than my paper clip, they both hit at the same time. I concluded that I needed to do more research on gravity.
I watched a few informational YouTube videos and read a few informational papers and discover that while gravitational force is determined by mass and distance, acceleration due to gravity is determined by aerodynamics and resistance. The fact that I dropped those two objects at such a low height meant that the differences in their aerodynamics were negligible. And so their acceleration due to gravity was virtually the same to the naked eye.
This last bit begins the process again, as I might next try to drop two objects from an airplane to see if their aerodynamics affected which reached the ground next. The scientific method is incredibly useful, but not for every situation. There are some large scale issues that might be too complicated to design an experiment for, such as trying to answer the question, what would happen if the moon crashed into the earth?
There is a difference between scientific theory and physical laws. Physical laws are things that apply universally in nature. They are fixed and do not change. An example would be Sir Isaac Newton's law of gravity, which states, any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This is something that, at least at this point in history, is immutable and constant in nature.
And our key term for today is scientific theory, a collection of observations that fit together in a broader picture. Scientific theories are usually thoroughly tested, but cannot be proven, only supported. However, they can be disproven. They also can be changed and revised as new information is gathered.
Scientific theory is different from the common use of the word theory in everyday language, because scientific theory is backed up by significant research. And example of a theory was the ancient scientist Ptolemy's theory that the Earth was at the center of our solar system. This knowledge was used to predict the movement of celestial bodies.
Repeated observation of celestial objects and calculations from retrograde motion supported this theory for 1,500 years, until it was eventually disproved in Copernicus's time, and replaced by the theory that the sun is at the center of our solar system. The Copernican theory that replaced it was simpler, more accurate, and required less assumptions about the way the universe worked than Ptolemy's theory.
In science, the goal of objectivity is paramount, meaning preventing personal bias, opinions, and interests from influencing thinking, interpretation, and/or reported findings is important. An example of subjective and objective thinking would be two people talking about nuclear energy might arrive at the same conclusion through subjective and objective thinking. Person One might say, I have a cousin who works in a nuclear power plant. And she gets sick all the time. Plus, I hate how ugly the plant is when I drive by. Nuclear power is dangerous. This is subjective thinking.
Person Two might say, according to research from a credible source, I discovered that people who work in nuclear facilities or manage the radioactive waste they produce are significantly more at risk to certain forms of cancer. Nuclear energy, if not properly managed, can prove more dangerous to human health than we think. This is objective thinking.
Now let's have a recap. We talked about what science is, what the scientific method is, the difference between laws and theories, and what scientific objectivity is. And don't forget our key term for today, scientific theory, a collection of observations that fit together in a broader picture. Well, that's all for this tutorial. I look forward to next time. Bye.
A collection of observations that fit together into a broader picture.