Notes: Doing Scientific Investigation - Lesson 1.1

Objectives

  • Determine the different models used by scientists; explain why scientists use models.
  • Determine the components of a scientific investigation.
  • Perform an experiment following the steps of the scientific method.
  • Conduct a simple scientific investigation to solve problems in the community using local materials.
  • Name laboratory equipment and identify their functions.
  • Observe safety measures in the use of laboratory equipment.
  • Demonstrate proper use and handling of science equipment.

Vocabulary Check

  • Pseudoscience: a combination of the Greek word pseudo, meaning "false," and Latin scientia, meaning "knowledge." It is any belief or practice mistakenly regarded as being based on the scientific method.

Science is a Continuous Search for Knowledge

  • Science comes from the Latin word scientia (scient-, sciens), meaning "having knowledge."
  • Science involves observations followed by experimentations, which lead to further observations and experimentations.
  • Example: Theory of Relativity (Einstein) states that space and time are relative, and all motion must be relative to a frame of reference.
  • Note: This reflects the iterative cycle of observation → experiment → refined understanding.

Science as a Product and a Process

  • Science as a product: an ever-changing body of knowledge.
  • Science as a process: ongoing investigation and thinking; a way of thinking and a way of investigating that involves:
    • Questions
    • Observations
    • Experimentations
    • Predictions
  • The dual view emphasizes that science evolves as new evidence emerges and methods improve.

Science, Pseudoscience, and Superstition

  • Science requires testing ideas through scientific investigation, gathering evidence, and critical analysis of data.
  • Pseudoscience: belief presented as scientific despite not arising from scientific investigation (e.g., Astrology).
  • Astrology: belief that movements of celestial bodies influence human lives; science has shown these alignments do not affect humans or animals or futures.

Science, Pseudoscience, and Superstition (Continued)

  • Superstition: belief not usually explained by natural sciences; often arises from curiosity and observation but lacks testing to verify claims.
  • Examples: a black cat crossing your path bringing bad luck; Flat-Earth Theory (disproved by proper scientific techniques).
  • Important nuance: some “weird beliefs” can inspire scientific discoveries if examined with proper techniques.

Branches of Science

  • Social science: study of people, culture, and societies. Includes economics, geography, history, law, education, sociology, psychology.
  • Natural science: aims to understand the natural world and its processes. Includes biology, chemistry, mathematics, physics.
  • Natural science can be pure or applied:
    • Pure science: study of new knowledge, discovery; may or may not have immediate practical applications.
    • Physical science vs Biological science (two divisions of pure science).

Branches of Science (Continued)

  • Physical science: study of nonliving things and their interactions:
    • Physics: matter, energy, and interactions.
    • Chemistry: matter, composition, structure, properties, changes, and energy changes.
    • Earth science: study of Earth, its composition, interior and surface processes, similarities/differences with space, weather and climate systems.
  • Subfields and roles:
    • Meteorologist: weather and climate.
    • Earth scientists: geological features on land and in oceans.
    • Geologists: rocks and geologic features.
  • Biological science (Biology): study of living things; includes all subspecialties of biology.
  • Applied science: use discoveries from pure sciences to create practical solutions; examples include Engineering, Computer Science, Medicine; Electronics and Environmental science.

Great Men and Women of Science

  • Aristotle (384-322 BCE) was a foremost natural philosopher who laid foundations for modern scientific thought and compiled material for an organized encyclopedia. 384-322\ \text{BCE}
  • Nicolaus Copernicus (1473-1543) challenged geocentric view; proposed heliocentric model with the Sun at the center and planets revolving around it. 1473-1543
  • William Harvey (1578-1657) described circulation of blood; foundational to modern physiology, biology, and medicine. 1578-1657
  • Louis Pasteur (1822-1895) established germ theory of disease; showed how heating (pasteurization) and vaccination prevent disease. Also linked to sterilization practices. 1822-1895
  • Marie Sklodowska Curie (1867-1934) first woman to win Nobel Prizes in Physics (1903) and Chemistry (1911) for work on radioactivity, isolation of radium, and discovery of polonium. 1867-1934

Filipino Great Men and Women of Science

  • Lourdes J. Cruz (Biochemist): National Scientist (2007); UP Diliman B.S. in Chemistry (1962); M.S. and Ph.D. in Biochemistry from University of Iowa (1966, 1968). Research on toxins from cone snails; published >120 papers.
  • Fabian M. Dayrit (Chemist): specializes in Organometallic chemistry; works on medicinal plants (Lagundi, Ampalaya, Moringa, Achiote); involved in National Integrated Research Program for Medicinal Plants to systematize indigenous research and boost local medicinal expertise.
  • Maria Corazon A. De Ungria (Forensic Scientist): head of DNA analysis Laboratory at the Natural Sciences Research Institute, UP Diliman; laboratory helps law enforcement solve crimes.
  • These scientists illustrate how science contributes to health, technology, and societal development.

Scientific Models

  • Scientists use a range of models to analyze, explain, and solve complex natural phenomena; models simplify real-world systems.
  • Types of scientific models (3 types):
    • Physical models: visible, tangible representations; link the real world with abstract systems (too large/small to see directly).
    • Conceptual models: visualize and conceptualize normally undetectable or highly complex systems.
    • Mathematical models: use mathematical computations to predict and quantify phenomena.

The Versatility of Scientific Models

  • Purposes of models:
    • Testing ideas: provide a controlled environment to test hypotheses and explore implications.
    • Making predictions: especially mathematical/computational models predict future events or trends (e.g., climate projections using historical data and current trends).

Assignment

  • How to be a Scientist? (referenced page 13)

Scientific Method

  • Scientists and engineers solve problems via the scientific method: an empirical, systematic process.
  • Steps and concepts:
    • Statement of the problem
    • Formulation of hypothesis
    • Testing/Experimentation
    • Analysis
    • Data
    • Drawing of conclusions
    • Hypothesis evaluation: if hypothesis is FALSE (partially true) or TRUE; results lead to reporting; modify hypothesis and repeat as needed.

Components of a Scientific Investigation

  • Statement of the problem:
    • Selecting a problem requires prior knowledge, information gathering from print/media, interviews, and environmental observation.
    • Answers: What questions do you have? What do you want to know? Why and how do things happen?
  • Formulation of hypothesis:
    • A hypothesis is a testable statement proposing a possible solution.
    • Forms: descriptive (overall description) or explanatory (underlying cause).
  • Testing of Hypothesis and Gathering Data:
    • Conduct an experiment; the purpose is to address the research question.
    • Types of experiments:
    • Controlled experiment: compares an experimental sample with a control sample; tests a hypothesis by changing a variable.
    • Variable: any characteristic, number, or quantity that changes; three kinds of variables exist in experiments (see below).
  • Variables definitions:
    • Independent Variable (IV): the factor that is deliberately changed or varied.
    • Dependent Variable (DV): the outcome observed in response to the IV.
    • Controlled Variables (CV): factors kept constant to prevent their influence on the outcome.
  • Types of experiments beyond the lab:
    • Natural experiments (quasi-experiments): observe variables without manipulation.
    • Field experiments: study real-world settings using scientific methods, common in social sciences (political science, economics, psychology).
  • Presenting and Analyzing Data:
    • Data should be presented systematically (e.g., in tables) to facilitate interpretation and pattern recognition; shows relationships between factors.
  • Drawing a Conclusion:
    • A concise summary of findings; evaluate alignment with the hypothesis.
    • If consistently supported, the hypothesis gains robustness; repeatedly tested results can contribute to a theory (a well-supported explanation for facts and phenomena).
  • Reporting of Findings:
    • After data collection, analysis, and conclusions, share results to contribute to the body of knowledge.

Laboratory Tools

  • A well-stocked toolbox is used for experimentation; common tools and uses include:
  • Beaker: open glass cylinder with pouring lip; used for mixing, stirring, heating liquids.
  • Reagent Bottle: stores and mixes chemicals; displays labels.
  • Bunsen Burner: small lab burner; vertical tube connected to gas; hot flame from gas/air mix; adjustable via base holes.
  • Burette: graduated glass tube with stopcock; precise dispensing and measurement of liquids.
  • Erlenmeyer Flask: conical shape; heated and stored liquids; wide bottom allows faster heating.
  • Evaporating Dish: heated liquids to evaporate.
  • Florence Flask: bulb-shaped bottom for even heating; used in distillation.
  • Funnel: transfers liquids to another container with reduced spill risk.
  • Micro Spatula: transfers small amounts of solids.
  • Mortar and Pestle: grinds solids into powders.
  • Pipette: moves small amounts of liquids; usually disposable plastic.
  • Ring Stand: supports items during heating; clamps/rings hold items above a Bunsen burner.
  • Test Tube Holder: holds test tubes during heating.
  • Test Tube Rack: holds test tubes upright when not in use.
  • Thermometer: measures temperatures of solids, liquids, gases; typical scales: Celsius, Fahrenheit, Kelvin.
  • Tongs: grips hot objects (flasks, crucibles, evaporating dishes).
  • Volumetric Flask: prepares solutions of fixed volume.

Safety Measures in the Laboratory

  • Follow safety procedures to avoid untoward incidents.
  • Always follow directions in the worktext or from the teacher; ask if unsure.

Safety Signs

  • Safety signs provide protection and caution for handling chemicals and substances.
  • Important signs to know:
    • Poisonous chemicals: dangerous if ingested, inhaled, or via contact.
    • Flammable or Extremely Flammable chemicals: stored in flame-resistant cupboards; volatile solvents can spread from unsealed containers.
    • Corrosive: avoid skin contact; can damage materials.
    • Oxidizing chemicals: release oxygen or promote combustion; keep away from flammable substances.
    • Keep away from foodstuff: harmful materials must be kept separate from edible materials.
    • Dangerous when wet: flooring may be slippery; walk with caution.
    • Flammable gas or liquid: symbol for transport or storage of flammable gases or liquids.

Closing

  • Thank you for listening; see you at the next meeting.