8th GRADE SCIENCE

1
8th GRADE SCIENCE

• STRAND 1
• THE NATURE OF SCIENCE
• NS 1.8.1 NS 1.8.3

2
THE SCIENTIFIC METHOD

• The Scientific Method is a series of planned
  steps used by scientists to solve problems. These
  are the steps
• 1. Ask a question or determine a problem.
• 2. Make a Hypothesis.
• 3. Gather data and test your hypothesis.
• 4. Analyze the results of your testing.
• 5. Draw a conclusion.

3
(No Transcript)
4
BIGFOOT!

• A Game and Fish officer in Little Rock received a
  phone call from a person in northwest Arkansas,
  claiming he had evidence of a Bigfoot sighting
  there.
• The caller stated they had a plaster cast
  footprint, a sample of weird looking hair they
  found on a barbed wire fence, an actual picture
  of Bigfoot, and, they had an eye-witness.

5
BIGFOOT

• Based on the data the officer gathered over the
  phone, he can make his HYPOTHESIS.
• I THINK THERE IS A BIGFOOT IN NORTHWEST
  ARKANSAS.
• Now what does the officer have to do?
• Go up there and gather the evidence. THEN
• Test the evidence!

6
ACTUAL PICTURE
7
HAIR SAMPLE
8
PLASTER CAST OF FOOTPRINT
9
BIGFOOT

• The officer gathered these 3 pieces of data. The
  eyewitness lived a few miles up in the hills, so
  he would save him for last.
• He sent the picture to a photo lab to be
  analyzed.
• He sent the hair sample to a lab to be analyzed.
• He decided to stake out the area where the
  footprint was located.

10
BIGFOOT

• He went to the area dressed in his camo, and hid
  in the bushes.
• After several hours he heard a loud THUMP!
• Then several seconds later another THUMP! Then
  another and another, it was getting closer.
• The officer saw a man who had a long metal pole
  with a metal cut out of a huge foot on the end of
  it. The man was slamming the foot into the
  ground, making footprints.

11
BIGFOOT

• The officer stepped out of the bushes and
  confronted him.
• After questioning, the man finally confessed that
  he had a whiskey still hid in the area, and he
  thought that if people thought there was a
  bigfoot monster in the area, they would be scared
  and stay away so he could make his whiskey.

12
BIGFOOT

• A day later, results from the hair sample and
  picture came back.
• The hair sample was that of a north American
  black bear.
• The picture was blown up 200 times, and a zipper
  could be seen in the back of it.

13
BIGFOOT

• The officer still had his eye-witness to check
  out. He drove 3 miles up the old dirt road to
  talk to the man.

14
BIGFOOT

• His dogs met him at the door!

15
BIGFOOT

• When the man came out, he was drunk as a skunk,
  and told him he had seen bigfoot, pink elephants,
  and flying saucers too!

16
BIGFOOT

• What at first seemed liked a good hypothesis,
  turned out to be false, but ONLY after testing
  the evidence.
• He now had to make his conclusion.
• THERE IS NOT A BIGFOOT IN NORTHWEST ARKANSAS!

17
VOCABULARY

• 1. CONTROL In an experiment, the standard for
  comparison.
• 2. VARIABLE Measurable factor, characteristic,
  or attribute of an individual or a system.
• 3. EMPIRICAL EVIDENCE Data that can be
  detected, observed, or measured.
• 4. HYPOTHESIS An educated guess. An
  explanation for a question or a problem that can
  be formally tested.
• 5. THEORY A hypothesis that has been tested
  many, many times by different scientists, and the
  results turn out the same.

18
VOCABULARY

• 6. SCIENTIFIC LAW - A descriptive generalization
  about how some aspect of the natural world
  behaves. A theory that has been tested over and
  over by many scientists, and is considered a
  fact of nature.
• 7. EXPERIMENTAL DESIGN The design of a suitable
  experiment to test a hypothesis.
• 8. DEPENDENT VARIABLE Factor being measured in
  an experiment, found on the vertical or Y-axis on
  a graph.
• 9. INDEPENDENT VARIABLE The one factor changed
  in an experiment, represented on the horizontal
  or X-axis on a graph.

19
VOCABULARY

• 10. SCIENTIFIC METHOD A series of problem
  solving procedures used by scientists.

20
(No Transcript)
21
EXPERIMENTS

• Coach Bales thinks he has come up with a SUPER
  DUPER GROWTH PILL
• His HYPOTHESIS (educated guess) is I believe my
  super duper growth pill will increase the size of
  a rat over a period of time
• His empirical evidence will be
• 2 rats from the same litter, as close in size and
  weight as he can get.
• Each rat will get the same kind of food and
  water, also in same amounts.
• 1 rat will be given the SUPER DUPER GROWTH PILL

22
GROWTH PILL EXPERIMENT

• Rat 1
• This rat will not be given the pill.
• He will be the CONTROL, the standard for
  comparison in the experiment.

23
GROWTH PILL EXPERIMENT

• Rat 2
• Rat 2 will get the SUPER DUPER GROWTH PILL!
• This will be the VARIABLE, or the changeable
  factor of the experiment.
• It is very important in an experiment that you
  only test one variable at a time.

24
GROWTH PILL EXPERIMENT

• Coach Bales will give each rat the same amount of
  food and water at the same time each day.
• Only rat 2 will get the growth pill.
• He will be compared to rat one to see if he grows
  more or not.
• After 2 weeks..

25
(No Transcript)
26
GROWTH PILL EXPERIMENT

• Based on the evidence that the rat given the
  growth pill did in fact get bigger in size, Coach
  Bales can now form a theory, a hypothesis that
  has been tested.
• His theory though, must be tested many more times
  by many different scientists before it can be
  accepted as a scientific law or a fact of
  nature.

27
SOMETIMES, EXPERIMENTS CAN BE BAD!!!!!!!!!!!!!!
28
(No Transcript)