Nature of Science

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Nature of Science
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Science is not just a subject in school but a
method for studying the natural world .Science
is a process that uses OBSERVATION,
INVESTIGATION, MODEL BUILDING and ANALYSIS to
gain knowledge about the natural world
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Scientists need to communicate their ideas

• Communication is the goal of all scientific or
  scholarly research. 
• It encourages repeated testing and clarifying of
  ideas
• Agreement of the scientific community is
  important to understanding and sharing of ideas
  to the public
• Science is cumulative, one discovery is often
  made based on the work of others. If you don't
  know what other people have done, you have to
  reinvent everything yourself!.

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Scientific explanations help us to understand the
natural world. However, explanations can change
or be further defined over time as more insights
and information become available.

• Newtons laws of Motion
• Einstein's Theory of relativity
• Drake Equation

This photograph not only shows the conversion of
energy to mass, but confirms Einstein's idea that
a light-particle will yield up its quantum of
energy all at once in a single burst.
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Scientific Discoveries
Abacus- 190 AD Use of the abacus, with its beads
in a rack, was first documented in China in about
190 AD. The Chinese version was the speediest way
to do sums for centuries and, in the right hands,
can still outpace electronic calculators.
Aspirin- 1899 Little tablets of acetylsalicylic
acid have probably cured more minor ills than any
other medicine. Hippocrates was the first to
realize the healing power of the substance. At
the turn-of-the-century, German chemist Felix
Hoffman perfected the remedy. Barbed wire- 1873
The world's most divisive invention was
conceived not to keep people in or out, but cows.
Barcode- 1973 Barcodes were conceived as a kind
of visual Morse code by a Philadelphia student in
1952. Now, black stripes have appeared on almost
everything we buy. Battery- 1800 In 1780s,
Italian physicist Luigi Galvani discovered that a
dead frog's leg would twitch when he touched it
with two pieces of metal. His friend, professor
Alessandro Volta made the first battery which
were voltaic cells stacked in a Voltaic pile.
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SCIENTIFIC METHOD FOR PROBLEM SOLVING

• Organized set of investigative procedures
• Not always a rigid set of steps
• Follows a general pattern
• Not all steps are followed, some are repeated
• Objective and tries not to have a bias as to what
  the results should be
• Experiments must be repeatable
• Do many trials of the experiment to ensure
  Validity
• Sometimes a Hypothesis needs to be revised after
  experimentation

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State the Problem or ask how or why something
occurs
Gather background information
Form HYPOTHESIS or possible explanation for a
problem using what you know and what you observe
Test the hypothesis by performing an experiment,
observing, building models, Or simulating a
situation using controlled conditions
Analyzing the data, record your observations in a
data table
Draw conclusions and decide if your hypothesis is
supported or not
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Visualizing With Models

• Scientists can not see or work with everything
  they are investigating. A model represents an
  idea, event or object to small or too large to
  work with. Models allow people to have a better
  understanding of the idea.

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Variable a factor that can cause a change in the
results of an experiment

• Dependent variable the value that changes, what
  you measure, the data
• Independent variable what you change in an
  experiment to see how it will affect the
  dependent variable
• Constant a factor that does not change when
  other variables change
• Control the standard you
• used to compare results

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HYPOTHESIS

• A suggested answer to a question or a problem
• Usually written as If Then Because
• Example If thicker paper towels soak up more
  water than thin paper towels, then thicker towels
  will absorb more water because they have more
  material.
• The more specific the hypothesis the better you
  will be able to evaluate the lab
• If independent Then Dependent

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Technology

• The application of science in our everyday lives

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Standards of Measurement

• Precision How closely measurements are to each
  other and how carefully measurements were made
  (hit a bulls eye)
• Accuracy compares a measurement to the real or
  accepted value (around a bulls eye)

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Metric System

• Called the International System of Units or SI,
  Le Systeme Internationale de Unites used
  throughout the world
• Base Units of Metric Measurement
• Meter -- length
• Liter -- liquid volume
• M3 or cm3 solid and gas volume (l x w x h)
• Gram -- mass
• Second -- time
• Celsius-- temperature

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Metric Prefixes

• 1km 1000m
• 100cm 1m
• 1000mm 1m
• 1cm 10mm
• 1cm3 1ml

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Practice Problems

• 1000mm ______cm ______m
• 1liter ______ml
• 450m ______km
• 77 cm -_____m
• 160 cm _______ mm
• 14 km _______ m
• 109 g _______ kg
• 250 m _______ km

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