How Does It Happen?
 Scientists


What experiments or tests were already
performed
What were the results of these tests
 Scientists

learn from other scientists
learn from themselves
What tests have I already performed and what
were their results
 Then
they draw conclusions or possiblities
 Before
performing any experiment you must
plan, plan, and plan



Write your plan in your laboratory notebook and
sketch the equipment that you will use
Make charts to record any data and/or
observations
State the idea that you are going to test
(hypothesis)
 While
the experiment is running, scientists
observe continuously


Record ALL data (whether it is what you
expected or not)
Even if at first glance the experiment looks like a
failure record all observations, it may be a
success in another way

In 1928, the Scottish scientist Alexander Fleming
was investigating disease-causing bacteria when
he saw that one of his cultures contained an area
where no bacteria were growing. Instead, an
unknown organism was growing in that area.
Rather than throwing the culture in the trash and
calling it a failure, Alex investigated the
unfamiliar organism and found that it was a type
of mold. This mold produced a substance that
prevented the growth of many disease bacteria.
What he found by questioning the results of a
“failed” experiment became the first modern
day antibiotic, penicillin.
Always retest to be sure of those first
observations.
 Test several times
 This is how x-rays were invented


A German scientist Roentgen was trying to investigate
cathode rays. He got unexpected results that he
knew that cathode rays could not have produced.
After further investigation he held his hand between
paper and the rays to see if these rays could travel
through many things. They, in fact, did travel
however they left an outline or a shadow of his
bones. Within a year a doctor used these “x-rays” to
help set a boys broken arm.
 We
know that science is observing, studying,
and experimenting to find the nature of
things.
 Science has two main branches


Social Science
Natural Science
 Natural
science tries to understand the
“nature” or “the whole universe”
Zoology
Life Science:
science of living
things
Botany
Many Other
Branches
Natural Science
Physical Science:
science of matter
and energy
Physics: Forces
and energy
Chemistry:
matter and its
changes
Geology
Earth Science:
science of earth
Meteorology
Many Other
Branches
 Life
Science or Biology – the science of living
things




Botany – the science of plants
Zoology – the science of animals
Ecology – the science of balance in nature
Medicine and agriculture are branches of biology
too
 Physical
Science – the science of matter and
energy


Chemistry – the science of matter and its changes
Physics – the science of forces and energy
 Earth


Science – the science of earth
Geology – the science of the physical nature and
history of the earth
Meteorology – the science of atmosphere and
weather
 This
classification of science seems like
everything fits into its own box
 However, there is a problem

As science has progressed, the branches of
science have grown out of their little boxes


Example – Chemists have begun to explain the
workings of chemicals that make up living things, such
as DNA. This science is called biochemistry, the study
of the matter of living things.
Example – The study of the forces that affect the Earth
is geophysics, which is both an Earth science and a
physical science.
Scientists who do experiments to learn more
about the world are practicing pure science (the
continuing search for scientific knowledge)
 Engineers look for ways to use this knowledge for
practical applications
 This application of science is called technology
 Example – Scientists who practice pure science
want to know how certain kinds of materials,
called superconductors, conduct electricity with
almost no loss in energy. Engineers focus on how
that technology can be used to build high-speed
computers.

 Technology
and science depend on one
another
 For instance, scientists did not know that
tiny organisms such as bacteria even existed
until the technology to make precision
magnifying lenses developed in the late
1600s.