Advanced Integrated Science

Unit One – Introduction to Science

Science – a system of knowledge and the methods you use to find that knowledge.

Two main types of science:

technology

  • The use of knowledge to solve practical problems.
  • iPhone example

pure science

  • Gathering new information or discovering new facts with no immediate use for it.

Branches of Science

The three main branches of science are:

1. Life Science – living organisms

  • i.e. biology

2. Earth Science – earth and space

  • i.e. geology and astronomy

3. Physical Science – matter and energy

  • i.e. chemistry and physics

Observations and Inferences

observations -- Information gathered through our five senses. Observations should be accurate and detailed.

example:

incorrect:The burning chemical smelled nasty.

correct:The burning chemical smelled similar to rotten eggs.

Observations can be quantitative or qualitative:

  • quantitative – factual descriptions that use numbers.

i.e. – Mr. Jones has two eyes.

  • qualitative – factual descriptions that do not use numbers.

i.e. – Mr. Jones has blue eyes.

inferences – A possible explanation or guess about an observation.

example: Mr. Jones is wearing a blue shirt, so his favorite color must be blue.

Units and Standards

In order for a measurement to be useful, a measurement standard must be used.

-- A standard is an exact quantity that people agree to

use for comparison.

-- When all measurements are made using the same

standard, measurements can be compared to each other.

  • Throughout history, people have used very inconsistent sources as measurement standards.

examples:

- small bean called carob became carat

- “yard” was the tip of nose to outstretched thumb

- “hand”

  • We currently use accurate, consistent methods to determine measurement standards that the entire world uses.

examples:

- platinum-iridium kilogram

- world atomic clock

The Scientific Method

The Scientific Method – an organized system of answering scientific questions.

  • We do this every day when we problem solve.

example: your car won’t start

Although there are many variations of the scientific method, they all contain the same basic elements:

Step One – make an observation.

Step Two – state the problem or ask a question.

Step Three – make one or more testable hypotheses.

  • hypothesis – an educated guess.

Step Four – design an experiment and test the hypotheses.

  • There are specific elements to a correctly designed experiment that must be met in order to make the data and conclusions reliable. (See below)

Step Five – analyze the results and draw conclusions.

  • Decide if your hypothesis is correct or incorrect, and make adjustments.

Designing an experiment

  • controlled experiment – an experiment in which only one variable is changed at a time.
  • control – a standard used for comparison.
  • constant – a factor that doesn’t change in an experiment.
  • independent (manipulated) variable – the factor adjusted by the experimenter.
  • dependent (responding) variable –Usually these are the experimental results.

When enough experiments have been done and enough data collected, scientists can develop a theory.

theory – an explanation based on many observations and supported by experimental results.

  • These may change as new information is discovered.

examples: big bang theory, evolution

scientific law – a rule that describes but doesn’t explain a pattern in nature and predicts what will happen under certain conditions.

model -- an idea, system, or structure that represents whatever you are trying to explain. Ideal for situations when what you want to observe is too small or large, or too dangerous to observe.

1.3 Measurement

Scientific Notation

  • Many numbers in science are either so large or small that it can be difficult to write out all the zeroes.

examples: A light year is the distance light travels in a single year – 9,460,528,000,000 kilometers.

Proxima Centauri is 4.2 light years away

total distance: 39,700,000,000,000 kilometers

It would take our fastest spacecraft more than 50,000 years to make the journey.

Scientific notation makes very large or very small numbers easier to work with.

example:

  • 300,000 = 3.0 x 105

The exponent 5 indicates there are 5 zeros after the 3

  • .00003 = 3.0 x 10-5

The negative exponent 5 indicates there are 5 decimal places to the left of the 3

Note: the coefficient MUST be between 1 and 9!!!

Limits of Measurement

Precision

precision – a gauge of how exact a measurement is.

significant figures – all the digits that are known in a measurement, plus the last digit that is estimated.

ex: 5.25 minutes has 3 significant figures

  • The precision of a calculated answer is limited by the least precise measurement used in the calculation.

Accuracy

accuracy – the closeness of a measurement to the actual value of what is being measured.

ex: a digital clock might measure all the way to the seconds, which gives it good precision, but if it is fifteen minutes slow it is not accurate.

Measuring Temperature

  • A thermometer is used to measure temperature.
  • There are three temperature scales;

water freezeswater boils

Fahrenheit scale 32o212o

Celsius0o100o

Kelvin273 K373K

  • The kelvin (K) is the SI base for temperature.
  • 0 K is absolute zero, the theoretical coldest temperature possible

Measurement Systems

  • The U.S. primarily uses the English system of measurements.

ex:

  • Why is this a problem?
  • Other nations use a system based on multiples of ten, developed by scientists in the late 1700s, called metrics.
  • This is now known as the International System of Units

International System of Units

  • All SI standards are universally accepted.
  • Each type of measurement has a base unit, to which a

prefix is attached.

ex: centimeterkilogram

  • The fact that it is based on multiples of ten make it much easier to convert between units than the English system.

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Int. Science Unit One