Agree or Disagree?

• When cows fall asleep standing up, it is easy (and fun!) to sneak up next to them and tip them over.

• Birds eating rice thrown at weddings swell up and die (even burst).

• Animals exposed to radioactive waste mutate and turn into other types of animals.

Agree or Disagree?

• Earthworms come up onto the sidewalks after heavy rain to avoid being drowned in their underground tunnels.

• People licking toads have hallucinations.• Lennon wrote better music than

Tchaikovsky.• Heaven is not in our solar system, but it is

somewhere in the universe.

Science involves…

• Using and extending the senses

• Observing and collecting

• Probing and testing

• Deductive hypothesis testing

• Inductive search for patterns

• Building increasingly accurate explanations based on evidence

Mendeleev and the Periodic Table of Chemical Elements

Fleming and the serendipitous discovery of the first antibiotic

Goodall and the willingness to break with convention

The Scientific Method

• There is simply no fixed set of steps that scientists always follow, no one path that leads them unerringly to scientific knowledge.

“The Scientific Method”

1) Question or Problem 2) Hypothesize

3) Predict Consequences 4) Experiment

5) Interpret Experimental Results

Experiments

• An experiment is a test used to determine if there is evidence to support a hypothesis

What is a hypothesis?

• A hypothesis is a guess or prediction about a phenomenon.

• Hypotheses can be stated as positive or negative.

• The “null” hypothesis predicts that there will be NO difference between experimental groups.

Write your own hypothesis

• Write your prediction for the outcome of the radish seed experiment

• You should also provide a REASON…why do you think the experiment will turn out the way it will?

What is a theory?

• A theory is an explanation that has a very large amount of evidence to support it.

• A fact is an observation about nature. A theory is an explanation. So a theory can never “become” a fact.

Experiment Titles

• Usually, experiments are titled in a format like this:

• “The Effect of _______ on _________”

• Sample title: “The Effect of Light on Growth of Radish seeds”

Experimental variables

• The ONE factor that you cause to be different between experimental groups is the MANIPULATED variable (also called INDEPENDENT variable).

• Sample: In the radish seed experiment, the manipulated variable is”Amount of Light”

Experimental variables

• The factor that you measure as the outcome of the experiment is called the RESPONDING variable (also called DEPENDENT variable)

• In the radish seed experiment, the responding variable is ___________.

• The responding variable is LENGTH of STEM, measured in millimeters.

Constants

• All other factors in the experiment must be controlled so they are the same for all groups.

• Examples of constants in radish seed experiment:

• Type of Petri dish type of seed

• Number of seed paper towel

• Water, Location temperature

Measure the responding variable

• Draw a data table for recording radish plant sizes

Date Light Dark

Writing an experiment description

• Title

• Hypothesis

• Short description of procedure

• Identify control and experimental groups.

• Name the manipulated, responding variables

• Identify five constants

Measurements

• Obtain a flexible plastic ruler and measure the length of the radish seeds today in millimeters.

• Record your data and your partner’s data in the data table.

Fact, Hypothesis, Law, Theory

• Fact = a stated observation• Hypothesis = a proposition that may

be investigated• Law or Principle = a description of

observable phenomena• Theory = an explanation based on

extensive evidence

Big Questions

• What is LIFE? • How can we tell things that are alive from things that were alive or were never alive?

OBSERVING LIFE and NONLIFE

• We now need to practice making observations of things and determining if they are alive, once alive, or never alive.

• This activity will allow you to practice writing CAREFUL and THOROUGH descriptions of what you see.

Life or Nonlife?

• Watch the short video clip of the Rover “Spirit” which is explored the planet Mars.

Life or Nonlife?

• Imagine that you have two soil samples returned from somewhere on Earth. Your job is to examine them, write a complete description of the objects you see, and determine whether objects are ALIVE, ONCE ALIVE or NEVER ALIVE

Observing soil samples

• I will place soil samples on your desk: today you will examine soil from a DESERT.

• Observe a part of each sample in a half Petri dish

• Use a microscope and a magnifying glass.

Observing soil samples

• Each person should write careful descriptions of soil samples

• Use as many adjectives as you can

• Describe size, shape, color of particles

• Explain WHY you think each object you see is alive, once alive or never alive

Observing soil samples

• You will be able to add to your observations tomorrow.

• TODAY< before you leave, please add clean spring water (with no chlorine) to the DESERT SOIL only.

• Add water until the cup is half full.

• Water sometimes activates dormant living things.

Soil samples: Day Two

• Observe forest soil and desert soil again, adding to your descriptions of the objects you see in the soil.

• Make small drawings of any objects you see in the soil.

• Make note of any changes you see in the samples today.

• (Use a pipette to add a few drops of desert water to the Petri dish, so you can look at it under the microscope

• Then you will turn in your written observations on Friday.

Observing plant growth:

• Take bean and pea seeds and put them in containers of soil under our light source.

• Water them consistently.

• Each day in class, take note of any changes that you observe.

The Borderlands of ScienceShermer, (2001)

• Normal Science– Empirical claims

– Vast body of evidence

• Borderland Science– Empirical work

– Growing body of evidence

• Pseudoscience– Fake science disguised as

normal science

– Lacks evidence

10 different areas of inquiry:

• Acupuncture• Astrology• Big Bang• Big Foot• Chiropractic

• Heliocentrism• Hypnosis• Neurophysiology of

Brain Function• Punctuated

Equilibrium• Search for

Extraterrestrial Intelligence (SETI)

The Borderlands of ScienceShermer, (2001)

• Heliocentrism, .9• Neurophysiology of Brain Function, .8• Punctuated equilibrium, .7 ……normal science• SETI, Hypnosis, .5• Chiropractic, .4 ……………borderland science• Acupuncture, .3• Astrology, Big Foot, .1 ………pseudoscience