What is Science?
Week 2
During the second week of class, we will discuss how to describe and define science. At the bottom of the page, there is an activity that we will complete during class.
The Weekly Pondering assignment is in this font, to distinguish them from the rest of the text. Please read the next section on scientific revolutions, and complete the associated assignment by 5:00 PM the Thursday before class. The submit button is at the bottom of the page.
Scientific Revolutions: A Hypothesis
We will begin with a hypothesis: it could be argued that scientific revolutions tend to be led by people who ask novel questions, and propose highly creative solutions. Since I am a physicist, I am going to consider just physics-based examples. Let us look at two.
The Ultraviolet Catastrophe
In the 19th century, physicists begun to realize that they had rather embarrassing problem: their equations predicted that the Sun should be emitting an infinite amount of light. This is now known as the ultraviolet catastrophe, and in this case the "ultraviolet" refers to the fact that infinite light emissions were predicted for high-frequency (viz., more energetic than violet) light. Not only was this prediction a priori absurd, but it explicitly contradicted emission data from the Sun. For decades this problem persisted, despite repeated attempts to solve it.
In 1900, Max Planck wrote a paper explaining how to solve this problem. At the time, it was widely believed that light was a wave, and indeed there was bountiful evidence for this view. Planck, however, asked a radical question in his paper: he asked what one would find if one assumed that light is emitted in packets, a bit like dollars and cents--in other words, he considered the possibility that light is a particle. Upon answering this question, he derived a model of light emission which not only made finite predictions, but closely matched the emission data. We now view this paper as one of the most important in physics.
Einstein's Theory of Gravity
Around 1906, Albert Einstein decided to write a model of gravity to supplant Isaac Newton's model. Although Newton's model had been nearly universally accepted for nearly 200 years by the early 20th century, it had two problems. First, it was not clear how the gravitational force was transmitted from one body to another. How does the Sun reach out and affect Earth via gravity, given that there is virtually only a vacuum between the two? Second, Newton's model of gravity was unable to fully explain the motion of Mercury's orbit. In particular, the closest point of approach of Mercury around the Sun, called the perihelion (this is a general term for the closest point of approach along an orbit), moves over time; Newton's model was unable to make accurate predictions of this motion. In late 1915, Albert Einstein finally publishes his theory of gravity, in which he conceptualizes gravity as a consequence of curved geometries, and not as a force at all. This solved both of the aforementioned problems.
These are merely two examples of scientific revolutions out of many, and so our hypothesis has been buttressed by only a few pieces of evidence. Nevertheless, the two above examples are commonly cited as two of the major accomplishments in modern physics, and they both involve novel and creative elements.
It is useful to think of counterexamples. Do a little research regarding specific examples of scientific progress, and try to find at least one example of a major progression in any scientific field that you think does not involve novel and creative questions and/or answers. Please describe this example in about a paragraph or so, and provide links and sources.
You must submit this assignment by 5:00 PM on the Thursday before class.
Falsifiability, Science, and the Law
The concept of falsifiability has found its way into legal interpretations. For example, in the landmark case McLean v. Arkansas Bd. of Ed. (here), in response a lawsuit regarding the Arkansas law Balanced Treatment for Creation-Science and Evolution-Science Act, which stipulated that "Public schools within this State shall give balanced treatment to creation-science and to evolution-science."
The court ruled that the law was unconstitutional, and in doing defined science via the following properties:
"More precisely, the essential characteristics of science are:
(1) It is guided by natural law;
(2) It has to be explanatory by reference to natural law;
(3) It is testable against the empirical world;
(4) Its conclusions are tentative, i.e., are not necessarily the final word; and
(5) It is falsifiable. (Ruse and other science witnesses).
Creation science as described in Section 4(a) fails to meet these essential characteristics. First, the section revolves around 4(a)(1) which asserts a sudden creation "from nothing." Such a concept is not science because it depends upon a supernatural intervention which is not guided by natural law. It is not explanatory by reference to natural law, is not testable and is not falsifiable."
Let us try to put the concept of falsification to use, to see if we can find critiques of the claim that science follows the above characteristics. Do you think there are examples of claims that are generally considered scientific hypotheses, and that also involve "creation 'from nothing' "? If not, please explain briefly (in about a paragraph or so, and provide links and sources) why you've concluded this; if so, please give at least one example. You do not have to read the court case linked to above.
You must submit this assignment by 5:00 PM on the Thursday before class.
Stream Video
To the left, we link to a short video that I took whilst on a hike.
Fluid Motion Investigation Activity
The picture of water being poured into a glass, just to the left, links to an applet. Open the applet, and choose the "flow" tab at the top left.
In this activity, we will use the applet to test a hypothesis(es) regarding the stream video above. First, watch the stream video again carefully and answer the following question:
Does the speed of the water seem to depend on the location of the water in the stream? If so, describe where the water flows faster and where it flows slower.
If your answer to the above question is yes, develop a hypothesis regarding what factor(s) causes the change in the water's flow speed. If your answer to the above question is no, develop a hypothesis about which apparent features of the stream bed are not affecting the water flow rate.
Open the applet. Devise an experiment to test your hypothesis.
Your conclusion should answer the following questions:
What is the relationship between cross-sectional area and flow speed?
Does the shape of the pipe affect the flow speed if the cross-sectional area is kept constant?
How does the cross-sectional area of the pipe affect the pressure?
Does the flow rate from the left input pipe affect your answers to the above questions?
Submit your work as a group in a PowerPoint (or equivalent) format; your presentation must have
an introduction that discusses the question your interested in answering;
a main results section where you make a hypothesis, discuss how you tested it, and answer the above questions and any other that you think are relevant; and,
a conclusion section where you summarize your presentation.
Submit the assignments
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