LS Scientific Investigation PP PDF

What is Science???
Solve problems, answer questions,
make the world better
Observation and Inference
Observation is an act or instance of observing a custom,
rule, or law; an act of recognizing and noting a fact or
occurrence often involving measurement with
instruments (using the 5 senses)
Inference is the act or process of inferring; a
conclusion or opinion that is formed because of known
facts or evidence
Observation or Inference???
Object A – basketball???
Object A – round and orange???
Object B – tennis ball???
Object B – green, round, fuzzy???
Object C – round, black and white???
Object C – is larger than object B???
Qualitative or Quantitative
Qualitative – Quality - Yes or No – Good or Bad
Quantitative – Quantity – How much – an exact amount
That picture is beautiful???
Qualitative - Good
That hamburger was fantastic??? Qualitative - Good
The Yankees scored 8 runs???
Quantitative - number
Blood glucose is 87 mg/dL???
Quantitative - number
Control-Compare results to – normal outcome
Constant-stays the same
Variables-factor in an experiment that changes
Independent variable-manipulated (I change)
Dependent variable-what we are measuring
Scientific Method
Step 1 Identify a problem-the question the experiment should answer
Step 2 Gather information-research information about the question
Step 3 Make hypothesis-predict what will you think will happen
(educated guess)
Step 4 Perform experiment-controlled experiment-one variable changes
Step 5 Record and analyze data-record observations and data
Step 6 Conclusion-summarization of results
States 2 things: 1) hypothesis is right or wrong 2) why? data
Spontaneous Generation
Francesco Redi’s experiment-Do flies come from meat?
Hypothesis: flies produce maggots
Experiment (Procedure)-jars of meat open and jars of meat covered
-controlled variables (dependant)-jar, meat, location, temperature,
-manipulated variables (independent)-gauze keeps flies away from
the meat
-responding variables-whether maggots appear or not
Maggots in open jar-flies would lay eggs in the meat
No maggots in covered jar-flies couldn’t lay eggs in the meat
Needham’s test of Redi-heated gravy
then left the bottle open (Anton van
Leeuwenhoek-made the first
microscope and found tiny objectscalled them animalcules) Needham
wanted to see if these animalcules
would grow spontaneously in the gravy
-Nedham claimed the heat killed any
living things in the gravy-but the
animalcules came from the gravy
Spallanzani’s Test of Redi’s
experiment-he thought that
Needham did not heat the
samples enough, Spallanzani
heated 2 bottles of gravy-left one
open and sealed the other-the
open bottle was teeming with
micro-organisms-the sealed
bottle remained organism free.
He Concluded that the gravy
could not produce living things.
Pasteur’s test of Spontaneous Generation
Boiled broth-with a crooked stem on the
bottle-the broth remained organism free
for a whole year-then he removed the
neck the broth was teeming with
Pasteur showed other scientist that living
organisms come from other living
Pasteur was a great scientist
This is part of the cell theory that living
things come from living things
These experiments proved that
spontaneous generation is not true
Collaboration of Scientists
How a Theory Develops (theory or law)???
Theory is a well tested explanation that unifies a broad range of
observations; a plausible or scientifically acceptable general
principle or body of principles offered to explain phenomena; an
unproved assumption NOT A LAW
Law is a statement of an order or relation of phenomena that so far
as is known is invariable under the given conditions; a general
relation proved or assumed to hold between mathematical or logical
Law of Gravity-will not change-concrete (states that every point
mass in the universe attracts every other point mass with a force
that is directly proportional to the product of their masses and
inversely proportional to the square of the distance between them)
Law of -will not change-concrete (no energy or matter can be
created or destroyed)