LECTURE 3 Observation, Experiments, Theories and Models PDF

OBSERVATIONS, EXPERIMENTATION, THEORIES & MODELS FOUN 1210 MODULE 1: Units 2.5-2.6 Dr. Gideon Ramtahal  OBJECTIVES 1. Describe the characteristics of scientific observations and experiments and discuss the relationship between them. 2. Describe the place of theories,...

OBSERVATIONS, EXPERIMENTATION, THEORIES & MODELS FOUN 1210 MODULE 1: Units 2.5-2.6 Dr. Gideon Ramtahal  OBJECTIVES 1. Describe the characteristics of scientific observations and experiments and discuss the relationship between them. 2. Describe the place of theories, laws and models in science. SCIENCE IS REGARDED AS AN EMPIRICAL DISCIPLINE What does this mean? Empiricism vs Rationalism  PLATO vs ARISTOTLE Ancient Greek philosophers (first scientists) – 5th century BC Plato (429 -347 BC) Aristotle (384-322 BC) Did not believe in empiricism Contributions have been more influential, particularly when it comes to Believed that all knowledge could be science and logical reasoning (deductive) obtained through pure reasoning (inductive), Knowledge gained through senses no need to actually go out and measure anything (domain of craftsmen and artisans) First to realize importance of empirical measurement, believing that knowledge RATIONALISM could only be gained by building upon what is already known EMPIRICISM WHAT ARE THE TWO MAIN CATEGORIES OF OBSERVATIONS?  OBSERVATIONS QUALITATIVE QUANTITATIVE  OBSERVATIONS QUALITATIVE QUANTITATIVE Using your senses to gather information Data is descriptive: colours, texture  OBSERVATIONS QUALITATIVE QUANTITATIVE Using your senses to gather information Made with instruments such as rulers, balances, thermometers Data is descriptive: colours, texture Data is measurable WHICH IS BETTER? Intellspot.com, 2021  QUALITATIVE VS QUANTITATIVE Both types of Observations are valuable in Science. However, in an experiment, quantitative observations can be precisely and objectively compared. Example: The road is long The road is 5 km long  QUALITATIVE VS QUANTITATIVE Both types of Observations are valuable in Science. However, in an experiment, quantitative observations can be precisely and objectively compared. Example: Qualitative- The road is long (describes) Quantitative- The road is 5 km long (measures)  It's a FACT!!! are observations that have been repeatedly confirmed and for all practical purposes is accepted as “true.” - Facts are statements that can be proven. - Facts may be true or false but can be proven (substantial evidence)  SCIENTIFIC FACTS A scientific fact is an undeniably true statement accepted by the science community. It can be proven to be correct through observations and testing. Scientific thinking, however, recognizes that, though facts are important, we can only be completely confident about relatively simple statements. Ecklund and Scheitle, 2007  SCIENTIFIC FACTS A scientific fact is an undeniably true statement accepted by the science community. It can be proven to be correct through observations and testing. Scientific thinking, however, recognizes that, though facts are important, we can only be completely confident about relatively simple statements. However, Truth in science - never final, what is accepted as a fact today may be modified or even discarded tomorrow Ecklund and Scheitle, 2007 WHAT IS AN EXPERIMENT?  WHAT IS AN EXPERIMENT? Experiment-A test or trial that produces evidence that can be used to answer a question or test a hypothesis.  BASICS OF AN EXPERIMENT Series of organized steps designed to test a hypothesis as part of the Scientific method. Two key variables in any experiment - What are they?  BASICS OF AN EXPERIMENT Series of organized steps designed to test a hypothesis as part of the Scientific method. Two key variables in any experiment - the independent and dependent variables. Can you differentiate between the two? Identify the independent, dependent and controlled variables below: Knowit, 2020  EXPERIMENTAL VARIABLES A scientist hypothesizes that the temperature at which an alligator’s egg is incubated will determine the sex of the alligator. What are the independent and dependent variables in this scenario?  EXPERIMENTAL VARIABLES A scientist hypothesizes that the temperature at which an alligator’s egg is incubated will determine the sex of the alligator. What are the independent and dependent variables in this scenario? TEMPERATURE INDEPENDENT  EXPERIMENTAL VARIABLES A scientist hypothesizes that the temperature at which an alligator’s egg is incubated will determine the sex of the alligator. What are the independent and dependent variables in this scenario? DEPENDENT  EXPERIMENTAL VARIABLES A scientist sets out to determine which of the fertilizers A, B and C will give the highest quality of CBD oil in one variety of Marijuana What are the independent, dependent variables and control in this scenario? Socratic, 2017 Is there a difference between an Observation and an Experiment?  Is there a difference between an Observation and an Experiment? Observation: the use of one of the senses (hearing, sight, touch, etc.) or measurement to gather information. Experiments don't just observe...  Is there a difference between an Observation and an Experiment? Observation: the use of one of the senses (hearing, sight, touch, etc.) or measurement to gather information. Whereas Experiments don't just observe... -Experiments actively impose some treatment to measure response.  BASICS OF AN EXPERIMENT Cont'd Some key types of experiments are controlled experiments, field experiments  EXPERIMENTS: CONTROLLED VS FIELD ENVIRONMENTS In performing experiments (large-scale or small-scale) -some experimenters have to intervene actively in the natural world Neutralization of acidic soils with lime to increase cocoa crop productivity Laboratory/Controlled (Artificial Cocoa Farm: Natural Environment Environment) EARLY TRIUMPHS OF EXPERIMENTS WILLIAM HARVEY'S FINDINGS Used scientific experiments to challenge ideas and knowledge about circulation in the body: Interfered with the course of nature Establish existence of a process of blood flow Looked at Cause and Effect relationship Arrived at a conclusion (but did not observe any connections between arteries and veins) His conclusions allowed for the prediction of existence of capillaries  William Harvey's Experiments (Modern view) Aird, 2011 Fig 1. Experiments on animals to assess blood flow Fig 2. Experiments on humans to assess blood flow  PREVAILING VIEW OF EXPERIMENTS ON CIRCULATORY SYSTEM Galen (c.130 AD - c.210 AD) – Harvey (1615): showed that Marcello Malpighi (1661) - discovered that arteries carry blood was passing from veins examined brain and major blood but believed that blood to arteries through heart and organs to demonstrate their was produced by liver and lungs having no microscope finer anatomical features - led then 'used up' by body unable to demonstrate to discovery of capillaries capillary blood vessels MMCDONALDWSD1ORG, 2019  GALILEO'S TAKE ON FREE-FALLING OBJECTS [Aristotle] [Galileo]  WHAT CAN WE CONCLUDE SO FAR? - Both Observations and Experimentation – essential for producing scientific knowledge (EMPIRICAL DATA) - Distinguishes science from other cognitive practices  WHAT IS A SCIENTIFIC LAW? - A statement of fact: describes what scientists expect to happen every time under a particular set of conditions. - Describes an observed pattern in nature without attempting to explain it. - Accepted to be ‘true’ and universal: repeatedly observe the same result in specific circumstances - Does not explain why the phenomenon exists or what causes it.  NEWTON'S LAW OF UNIVERSAL GRAVITATION Law of Gravity Every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them  WHAT IS A SCIENTIFIC THEORY? - General statement(s) that correctly explain(s) all experimental observations about the behaviour and properties of a large variety of objects or systems - Well-substantiated explanation acquired through scientific method and repeatedly tested and confirmed through observation and experimentation CHARACTERISTICS OF A GOOD SCIENTIFIC THEORY - Useful (describes & explains observed phenomena) - Empirically Testable & Falsifiable - Based upon Controlled, Repeated Experiments - Correctable & Dynamic (changes are made with new data) - Progressive (achieves all that previous theories have and more) - Tentative (admits that it might not be correct, does not assert certainty) NEWTON'S THEORY OF UNIVERSAL GRAVITATION Theory of Universal Gravitation (1680s) Idea that gravity was a predictable force that acts on all matter in the universe, and is a function of both mass and distance Heath, 2016 SCIENTIFIC THEORY SCIENTIFIC LAW - Explanation of a natural - An empirical statement of great phenomenon with a broad BOTH BASED ON generality of something which HYPOTHESES range of significance and seems to always be true application -Can be used to make predictions - Can often be explained - Cannot be explained using mathematics mathematically -Can be revised - Explanation of observed with new - Description of an observed phenomenon evidence phenomenon….  What scientific LAW could be applied here? Photo credit: BeautifulBarbados  What scientific LAW could be applied here? Force (F) required to hit that mango with the stone F= m x a where: m= mass of stone a= acceleration Photo credit: BeautifulBarbados  What scientific LAW could be applied here? Work (W) or energy required to hit the mango with the stone W= F x d where: F= Force needed d= distance stone needs to travel Photo credit: BeautifulBarbados  What scientific THEORY could be applied here? Photo credit: BeautifulBarbados  What scientific THEORY could be applied here? Theory of Universal Gravitation Gravity a predictable force that acts on the stone, and is a function of both mass and distance Photo credit: BeautifulBarbados  What scientific LAW/THEORY could be applied here? Photo credit: iFete.ca 2013 Does a scientific THEORY progress into a LAW and vice versa? No, it does not. However, the development of one often triggers progress on the other. DO YOU KNOW OF ANY OTHER SCIENTIFIC THEORIES OR LAWS?  TYPES OF SCIENTIFIC THEORIES Astronomy: Big Bang Theory Biology: Cell Theory; Theory of Evolution; Germ Theory of Disease Chemistry: Atomic Theory; Kinetic Theory of Gases Physics: General Relativity; Special Relativity; Theory of Relativity; Quantum Field Theory Earth Science: Giant Impact Theory; Plate Tectonics ck-12.org, 2021 MODELS WHAT'S A SCIENTIFIC MODEL?  A SCIENTIFIC MODEL IS: A representation of an object or a system imagined mechanism Models are representations of reality (complex): scaled-up (physical model of a virus particle) or scaled-down (model of the solar system)  WHAT ARE SOME DIFFERENT TYPES OF MODELS? Physical – representation of an object or a system Mathematical – made up of numbers, equations Conceptual – represent system of ideas e.g. origin of life from chemicals (more abstract) – can be scaled-up or scaled-down  ADDITIONAL IMPORTANT CONCEPTS OF MODELS - Explanatory purposes: many theories are easier to understand with the use of a model - Use models to make and test predictions - Alternative models: different models to explain same phenomenon - Caveats: Can be powerful but can also be misleading - Models & Scientific Progress: models can only be as accurate as the current state of scientific knowledge about phenomenon they describe CAN YOU NAME SOME MODELS THAT WE ARE CURRENTLY USING IN THE REGION? PANDEMIC- CORONAVIRUS EPIDEMIOLOGICAL MODELS- CORONAVIRUS WEATHER  SPHAGETTI MODELS- HURRICANES “important to note that the spaghetti models are all based on several uncertain predictions and need to be taken with caution” CAN ANYONE GUESS WHAT THIS IS A MODEL OF?  SUMMARY Empirical evidence is information that researchers generate to help uncover answers to questions that can have significant implications for our society Observations and Experiments are an essential part of gathering empirical data Models, Theories, and Laws are used to help scientists analyze the data they have already collected or point them in the direction of new discoveries 1. Read Student Course Guide 2. Read Course Manual: UNIT 2.4 3. Submit Seminar Topics 4. Prepare Reflective Journal [Sept 30, 2024] 5. Self assessment 1 available