What is Science?

Is it just a bunch of facts?

Is it always true?

What about experiments?

What is Science? I

The dictionary says:

1. The observation, identification, description, experimental investigation of phenomena. 2. Methodological activity, discipline, or study.3. An activity regarded as requiring study and method.4. Knowledge gained through experience.

from Latin - scientia = knowledge

What is Science? II

For most Scientists, Science is the process of finding things out.

Richard Feynman: “Science is a way of not fooling yourself.”

Robert Oppenheimer: “Science is not everything, but science is very beautiful.”

Science is a process

Science is a process of getting ever closer to the best description of everything in the cosmos.How things work, the relationships between them, the seeming rules that regulate them.

This process is often called the Scientific Method, and is a bit more complex than some teachers have had you memorize.

Scientific Method 1

Anyone and Everyone is a Scientist! All have used this process at various times in their lives.

The first requirement, and the first step is:

Observation & Curiosity

Scientific Method 2

The QuestionWOW!!!

“I wonder how that works”

“I wonder why it happens like that”

“What would happen if…”

Scientific Method 3

The Hypothesis

“I predict if I do this, that will happen.”

A Testable Prediction of Outcome(a testable statement of belief)

Scientific Method 3.1

What do you mean a “testable prediction of outcome”? My teacher said it was an “educated guess”

Most people stress the “guess” part - and that isn’t quite right.

The Hypothesis must be Testable or Verifiable via experiment. If it can’t be, it isn’t Science!!!

Scientific Method 3.2

Example: There is life on other planets. OK, how can you realistically / easily test it?

Now?

Example: Intelligent life may be detected via their radio broadcasts near 1420 MHz. OK, how can you test it? Use a Radio

Telescope to “listen” at that frequency, and analyze it SETI @ Home is doing that!!

Scientific Method 4

Experimental Design Now you have to design an experiment to support or not support your hypothesis.

In many cases you need an Experimental Group and a Control Group to compare it to.

Scientific Method 4.1

Support or Not Support?

Your experiment doesn’t “Prove” or “Disprove” your Hypothesis, it only Supports it, or Does Not Support it.

Proof is accepted only after many repetitions of the experiment by different people.

Scientific Method 4.2

Experimental and Control Groups

In doing an experiment, you have to be able to compare two groups. One that you performed the change on, and another that you treated exactly the same, but without the one variable you were testing for.

Scientific Method 4.2.1

The Control group is the one you haven’t performed the change on.

The Experimental group is the one you have performed the change on.

Both groups must be similar! – have the same characteristics.

!!! You can only perform one change or variation at a time. Otherwise, you can’t tell which change was responsible for the effect you have seen!!!

Scientific Method 4.3

Repetition

Running an experiment once only, is not a convincing support for a hypothesis. The experiment must be repeated. Many times.In fact, to be considered to be proved, it has to have been repeated many many times, and in some cases this takes years!

Scientific Method 4.4

Explicit and Specific Steps

In designing an experiment, you must write out the exact steps to be performed. With times, quantities, methods. This insures your repetitions will be the same each time, and that others can repeat your experiment.

Scientific Method 4.5

Data Collection

What data do you need to collect to test your hypothesis?

Construct a Data Table to enable you to record your data.

Scientific Method 4.6

Materials

What materials, facilities, surroundings will you need to test your hypothesis.

What safety equipment and measures will you need to conclude your experiment safely?

Scientific Method 4.7

Safety

OK, I’ll say it again, SAFETY. You have to consider what might go wrong with your experiment. Explosions, Toxic Waste, Poison Gas, Broken Glass, Chemicals in your eyes. How can you PREVENT those things??? How can you ESCAPE???

Scientific Method 5

Experiment!

Do the Experiment!Some experiments take seconds to perform, others take minutes, hours, days, weeks, months, years, decades or longer!!Take care to do it right!

Scientific Method 5.1

Data Collection

Collect your data and write it down immediately in your data table or notebook.Data should be written in pen. Mistakes in writing should be crossed out with a single line, and the correction entered.This lets you and others check things later.

Scientific Method 6

Data Analysis

Mathematical Analysis, Graphing, Statistics, and more.

Scientific Method 6.1

GraphingA useful technique to visualize data!Every Graph must have certain features. Title - What the graph is about Axis - Intervals must be consistent

The distance from 0 to 5 has to be the same as 5 to 10 Labels - each axis is labeled for measurement and

units Key - To indicate the different data graphed.

Scientific Method 6.1.1

Graphing done wrong - what’s wrong here?

Heating Lab

20

212526

32

0

Temp

0 5 10 15 20 25 30

Scientific Method 6.1.2

Graphing done right

Solar Warming - White(1) &Black(2)

0

10

20

30

40

50

0 10 20 30 40

Time (Minutes)

Tem

pera

ture

(°C

)

Series1

Series2

Temperature

C

Scientific Method 6.2

Statistics 1

The Average is also called the Mean

Add all the values together, then divide by the number of values.

2.5, 3, 4, 3.5, 4.5, 3.5 added = 21

21/6 = 3.5 the Average is 3.5

Scientific Method 6.2.1

Statistics 2

Standard Deviation

Standard Deviation measures how far away from the average a number is. This is best done with a statistical calculator. The greater the Standard Deviation, the more random the results are. To be Significant, the experimental results must be more than one Standard Deviation from the mean.

Scientific Method 7

Conclusion

The conclusion is actually the simplest part of a “real” science experiment. You declare either: The Hypothesis is Supported The Hypothesis is Not Supported

Scientific Method 7.1

Conclusion continued

For most school lab write ups, you will be asked to include comments on what you learned, what you could have changed to make it better, what mistakes you may have done, and more…

Scientific Method 8

Communication

Central to the overall science communities efforts to learn more things is the idea of sharing your information. This is done through Scientific Journals (Magazines). This means you have to publish your experiment so others can review it and learn.

Scientific Method 8.1

Both Positive and Negative results need to be communicated. It may be just as important to have not supported your hypothesis as supported it.

Scientific Method 8.2

Most research is published in refereed journals, some is published on web-sites, or web-journals. Most web-journals are not refereed.

Refereed means that other scientists have reviewed the experiment and consider it to be done correctly.

Scientific Method 8.3

Some research is not published. This occurs when a company performs it and wishes to keep it a secret from competitors.They may use it to produce a new medicine, chemical, or process.

Scientific Method 9

New Hypothesis

Based on your experiment, what do you want to test next? What can you change to understand things better?

Go to Scientific Method 3

Stories of The Method in Action

The Waving Lizard

Teflon

Penicillin

Natural Selection and Evolution

The Electric Light

Mendel and the Peas

Any Questions?

Disclaimer

AlohaI put together these power points for use in my science classes.You may use them in your classes.

Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners!

Ted Brattstrom