CSET Lesson 1

What is Science?

The fundamental concept of science, the one that separates science from other fields of human knowledge is expressed in the following statement:

Scientific statements must be capable of being falsified by experiment.

If a statement cannot be disproven then it is not a scientific statement.


Discuss which of these are scientific statements?

"The world is made of atoms, small indivisible particles." (Richard Feynman, The Feynman Lectures on Physics) More on the atomic theory

"The entire moon is made of green cheese." (John Heywood : Proverbes (1546) photo data and Paul Hewitt, Conceptual Physics)

"Black holes are gateways into a universe outside the observable universe in which we live(Note no information has ever been observed to cross from inside to outside across the event horizon of a black hole.)" (Lee Smolin, The life of the cosmos) More on Black Holes.

"The Universe has 10 dimensions. (Note, all but three space and one time dimension of these ten dimensions are rolled up into balls that are twenty orders of magnitude smaller than we can measure at the current time)." (To find out more about string theory read Brian Geene, The Elegant Universe , and for the opposing view read The Trouble with Physic by Lee Smolin.".)

"Chickens 'see' the crater illusion (Crater illusion a photograph of a crater looks like a hill if the picture is rotated so that the illumination in the photo comes from the bottom.)" (Paul Doherty, Class notes.)

"Life exists somewhere on Mars" article by Harold Egeln, the Mars Society

"Carbon based life exists on the surface of the regolith of Meridiani Planum on Mars." Paul Doherty after an article from Space.com

Some quotes

"Scientific research consists of seeing what everyone else has seen but thinking what no one else has thought." Albert Szent-Gyorgi

"If it can't be expressed in figures it isn't science it's opinion." Robert Heinlein.

"Believe half of what you see and none of what you hear." Dinah Craik 1858

Let's look at a few introductory examples.

At the Exploratorium we begin our scientific explorations by asking the simple question

"What do you see?"

This is a wonderful question. It has no wrong answer.

And yet, different people look at the same exhibit and see different things.

After hearing descriptions of what people see we continue with the question of

"What's Going On?"

Now we enter the realm of scientific hypothesis, or inference. To be scientific a hypothesis must be falsifiable, that is it must be possible to prove the hypothesis wrong by experiment.

So whenever someone makes a hypothesis for how an exhibit works a scientist immediately thinks,

"How can I test that statement?"

1. Sometimes we can use the exhibit itself to test the hypothesis,

2. sometimes we have to bring in outside materials like a meter stick or a spectroscope,

3. sometimes the test is impossible to do at the exhibit but yet testable in a scientific laboratory with advanced equipment.

4. sometimes there is no way to test the hypothesis.

The first three cases certainly involve scientific statements.

The fourth one does not. Although there are two versions of the fourth case.

In version the statement is untestable today but it will become testable in the future as instruments improve. In the other there is no way at the present time to even envision a future way to test the hypothesis.

An aside on honesty.

In the third case above the work is done by someone else in a laboratory who then reports the results of their tests in a scientific journal. The progress of science depends on scientists telling the truth about the results of their tests. Being caught lying in a scientific publication results in the "scientific death penalty." You will be excluded from scientific research forever.

So, scientists trust other scientists when they publish results...mostly.

The problem comes when nonscientists publish results. Scientists cannot trust the publications of nonscientists as much as they do those of other scientists, because the nonscientist has little to lose by falsifying data.

A final note

Scientists must know their subject deeply. You can always ask a scientist

"How do you know that?"

after he or she makes a statement about their field of study. They must be able to tell you about the experiments that have been done to provide the data for their statements.

Teachers must know the breadth of science how one part of science relates to other parts, and how it is applied in everyday life.

It is difficult to be a scientist and a teacher, to know the depth and breadth of science.

For more thoughts on the nature of science.

A Science Teacher Looks at Science.

Atomic Theory, When it was proposed in the 1800's, the atomic theory helped explain chemistry. For example why one volume of oxygen combined with two volumes of hydrogen to make two volumes of water vapor. with atomic theory 2 H2 + O2 = 2 H2O. And yet it could not be falsified. There was no way to disprove the existence of the possible mythical atoms. It wasn't until 1905 when Albert Einstein showed that the atomic theory made testable predictions about the mathematical analysis of Brownian Motion. The analysis was done by Jean Perrin who received the Nobel prize for his work. By 1908 most scientists accepted the atomic theory as a correct scientific hypothesis. Today we can make images of individual atoms. Here is a fantastic article Atomic Theory. at http://physicsweb.org/articles/world/18/1/3/1

Black Holes, Experiments indicate that black holes exist. Observations from telescopes, stars orbit massive objects that are invisible. Orbiting blobs of incandescent gas suddenly vanish when they fall through the even horizon of a black hole. The hypothesis is that information can never escape from a black hole. This would be falsified if information was ever seen to come out of a black hole.


Scientific Explorations with Paul Doherty

© 2005

10 October 2005