Jamie Hale

Jamie Hale

Tuesday, August 25, 2009

Science Matters

The information below was originally published at University of Louisville's Sciboard. It has be reprinted with permission from Univ of Louisville Professor Thomas Cleaver.

General Science

Q. What is a Scientist

Ans. Although a person with an advanced degree might claim to be a scientist, the true test of the scientist is how one thinks. A good scientist:
· Excepts nothing in science absolutely.
· Is willing to change his opinions based on new data.
· Does not rely on Authority.
· Thinks critically.
· Knows that extraordinary claims require extraordinary proof.
· Has an open mind.
· Relies on logic and reason.
· Knows how to form hypotheses and test them.
· Respects the scientific method.
· Examines all the data, not just the data that support his or her view.
· Builds on the work of others, giving them appropriate credit.
· Documents his or her experiments so they can be duplicated by others.
· Knows that if a claim is made, the claimant must provide the proof. (It is not up to others to disprove it.)
· Is intellectually honest.

Q. What is a Science?

Ans. Many people think science is a collection of facts: Hydrogen combines with oxygen to form water. The speed of light is 299 800 000 meters/second. Man evolved from ape-like ancestors. These facts are the products of science but they themselves are not science.

Science is a method, a technique, for looking at the physical world and finding out the facts. It is a search for truth -- the kind of truth that can be verified and quantified.

The basic tool of science in its search for truth is called "the scientific method." This consists of making a "hypothesis" and conducting an experiment. A hypothesis is a theory or assumption that must be tested.

As an example, suppose a scientist forms the following hypothesis: "Light stunts the growth of mushrooms." She then tests the hypothesis with an experiment using 2 sets of mushrooms. One set (the control group) is put in a dark basement. The other (the test group) is put in a sun-lit yard. After a week, she measures the height of all the mushrooms in each group.

She finds that the test mushrooms raised in sunlight grew an average of 0.8 centimeters. The control group mushrooms raised in the dark grew an average of 1.5 centimeters. She then concludes that her hypotheis was correct: Light DOES stunt the growth of mushrooms.

No "fact" of science is ever proven beyond doubt. All conclusions of science are always open to question as discoveries and new understandings occur. A scientist must always stand ready to cast aside his fondly held beliefs as new evidence is discovered.

Returning to the mushroom example, suppose the scientist's conclusions were challenged. Someone says, "Dry soil stunts the growth of mushrooms. Your outdoor mushrooms were in dryer soil than your basement mushrooms." To prove her results are valid, the scientist may have to repeat her experiment while making sure that the moisture for both groups of mushrooms is the same.

An experiment that demonstrates a hypothesis must be "repeatable". This means that anyone who performs the experiment correctly should get the same results. In the above example, the scientist should be able to explain her methods carefully enough that her mushroom experiment succeeds when anyone does it. If the experiment is not "repeatable", no one should be expected to believe her results.

Good science is painstaking, slow, and full of disappointments. But its record of success is unsurpassed for determining the truth of how the world works.

Q. What is the Scientific Method?

Ans. The scientific method is the best way yet discovered for telling the difference between truth and lies and delusion. The simple version looks something like this:

1. Observe some aspect of the universe.
2. Invent a theory to explain what you have observed.
3. Use the theory to make predictions.
4. Test those predictions by experiment.
5. Modify the theory in the light of your results.
6. Go to Step 3.

Usually, you can trust other scientists to follow the scientific method. So when a scientist claims to have done a certain experiment and obtained a certain result, you can usually believe it. This allows scientists to build on the work of others.

Q. What is Theory?

Ans. In scientific terms, a "fact" is an observation, such as "the sun rose today". This fact is explained by the "theory" that the earth is round and spins on its axis.

Many times, theories are so widely accepted that they are treated as fact. The "theory of gravity" and the "theory of evolution" are accepted as fact by virtually all scientists.

A theory that has not yet been tested is called a "hypothesis".

Some "theories" are untestable, and are therefore unscientific. You assert, for example, that you are the only person in existence, and that all reality is but a product of your imagination. This is the theory of solipsism. There is no way that anyone can prove that your theory is false. Therefore it is unscientific.

The solipsist theory may be true, but it falls into the realm of philosophy, not science.

Q. Can Science Prove Anything?

Ans. Yes and no. It depends on what you mean by "prove".

Suppose you have a theory that when you throw something into the air, it will fall back down. You test your theory by throwing many objects into the air, and they all fall down.

Have you proven your theory beyond doubt? No. The next object you throw might hover, or go off into orbit. But the theory is "proved" for most practical purposes.

Theories and facts (even everyday ones, not scientific ones), can be thought of on a scale of certainty. Your theory that things fall down is near the top. Down near the bottom is "the Earth is flat". Near the middle might be "I will live to be 80."

On this scale, no scientific theory can ever get all the way to the top (or the bottom), but reasonable people accept those that are near the top.

Q. What is Occam's Razor?

Ans. This is the scientific principle that says we should look for the easy explanations first.

If you have 2 theories that both explain the facts, take the simplest one. You won't always be right, but that's where the smart money is.


Your friend calls you and says he's in Miami. Moments later, he knocks on your door.

Theory 1: You're friend teleported from Miami.
Theory 2: You're friend was lieing about being in Miami.

Occam's razor says to select Theory 2. It doesn't require belief in an unproven mode of travel (teleportation).

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