Principles and Branches of Science

• Science employs a systematic and organized methodology to comprehend the natural world, incorporating observation, experimentation, and analysis.
• Its objective is to uncover and elucidate facts and principles, ultimately leading to the formulation of theories and laws.

Core Principles

• Objectivity ensures scientific investigations remain unbiased, anchored in empirical evidence instead of personal sentiments.
• Empiricism underscores that knowledge is primarily derived from sensory experiences, highlighting observation and experimentation.
• Skepticism requires scientific claims to undergo questioning and rigorous testing before being accepted.
• Reproducibility dictates that experiments and observations must be repeatable, ensuring the validity of their results.
• Parsimony favors the simplest explanation that adequately accounts for the evidence (Occam's Razor).

Branches of Science

• Natural Sciences explore the physical world.
  • Physics investigates matter, energy, and their interactions.
  • Chemistry studies the composition, structure, properties, and reactions of matter.
  • Biology examines living organisms, including their structure, function, growth, origin, evolution, and distribution.
  • Earth Sciences delve into Earth's structure, properties, processes, and evolution, encompassing geology, oceanography, and meteorology.
  • Astronomy studies celestial objects, space, and the physical universe.
• Social Sciences delve into human behavior and societies.
  • Sociology studies social behavior, institutions, and structures.
  • Psychology investigates the mind and behavior.
  • Economics studies the production, distribution, and consumption of goods and services.
  • Anthropology studies human societies, cultures, and their development.
  • Political Science studies political systems, behavior, and policies.
• Formal Sciences employ formal systems for knowledge generation.
  • Mathematics explores abstract structures, relationships, and patterns.
  • Logic studies the principles of valid reasoning and inference.
  • Computer Science studies computation, automation, and information.

Scientific Method

• Observation involves identifying a phenomenon or problem.
• Question involves formulating a question about the observation.
• Hypothesis involves developing a testable explanation or prediction.
• Prediction involves predicting the outcome of testing the hypothesis.
• Experiment involves designing and conducting experiments to test the hypothesis.
• Analysis involves scrutinizing the data collected from the experiment.
• Conclusion involves formulating a conclusion based on the data analysis, either supporting or rejecting the hypothesis.
• Communication involves disseminating the results and conclusions within the scientific community.

Scientific Theories and Laws

• Scientific Theory: A well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation.
• Scientific Law: A statement that describes an observed regularity or pattern in nature, often expressed mathematically.

Measurement and Units

• Quantitative measurements are crucial for scientific accuracy and reproducibility.
• SI Units (International System of Units):
  • Length: meter (m)
  • Mass: kilogram (kg)
  • Time: second (s)
  • Electric Current: ampere (A)
  • Temperature: kelvin (K)
  • Amount of Substance: mole (mol)
  • Luminous Intensity: candela (cd)
• Derived units are combinations of SI base units (e.g., velocity in m/s).

Data Collection and Analysis

• Data can be quantitative (numerical) or qualitative (descriptive).
• Quantitative data is analyzed using statistical methods to identify patterns, correlations, and significance.
• Qualitative data is analyzed through interpretation and coding to identify themes and meanings.

Statistical Analysis:

- Descriptive Statistics: Summarize and describe data (mean, median, mode, standard deviation).
- Inferential Statistics: Make inferences and generalizations about a population based on a sample (t-tests, ANOVA, regression).

Scientific Instruments

• Microscopes are used to view objects too small to be seen with the naked eye.
  • Optical Microscopes use visible light and lenses.
  • Electron Microscopes use electron beams for higher magnification and resolution.
• Telescopes are used to observe distant objects in space.
  • Optical Telescopes use lenses or mirrors to gather and focus light.
  • Radio Telescopes detect radio waves emitted by celestial objects.
• Spectrometers are used to analyze the spectrum of light emitted or absorbed by a substance.
• Particle Accelerators are used to accelerate particles to high speeds for studying their interactions.

Controlled Experiments

• A controlled experiment involves manipulating one or more variables while keeping others constant.
• Independent Variable: The variable that is manipulated by the researcher.
• Dependent Variable: The variable that is measured to see if it is affected by the independent variable.
• Control Group: A group that does not receive the experimental treatment, used as a baseline for comparison.
• Experimental Group: The group that receives the experimental treatment.
• Blinding: A technique where participants (single-blind) or both participants and researchers (double-blind) are unaware of who is receiving the treatment to minimize bias.

Observations vs. Inferences

• Observation: Direct gathering of information through senses.
• Inference: Interpretation or conclusion based on observations and prior knowledge.

Models in Science

• Simplified representations of complex systems or phenomena.
• Types of Models:
  • Physical Models: Tangible representations (e.g., a model of the solar system).
  • Mathematical Models: Use equations to describe relationships (e.g., population growth models).
  • Conceptual Models: Diagrams or flowcharts that illustrate processes (e.g., the water cycle).
  • Computational Models: Computer simulations to predict outcomes.

Errors and Uncertainty

• Errors are deviations from the true or expected value.
• Types of Errors:
  • Systematic Errors: Consistent and repeatable errors (e.g., a miscalibrated instrument).
  • Random Errors: Unpredictable variations in measurements.
• Uncertainty: The range of possible values within which the true value is likely to lie.
• Error Analysis: Evaluating and quantifying the magnitude and sources of error in an experiment or observation.

Ethics in Science

• Honesty: Reporting data and results truthfully and accurately.
• Integrity: Adhering to ethical principles in research design and conduct.
• Objectivity: Minimizing bias in data collection, analysis, and interpretation.
• Openness: Sharing data, methods, and results openly with the scientific community.
• Credit: Giving proper credit to the contributions of others.
• Social Responsibility: Considering the potential impacts of scientific research on society and the environment.

Peer Review

• A process where scientific work is evaluated by other experts in the same field.
• Purpose: To assess the validity, significance, and originality of the research before publication.

Hypothesis Testing

• Null Hypothesis (H0): A statement of no effect or no difference.
• Alternative Hypothesis (H1): A statement that contradicts the null hypothesis.
• Significance Level (α): The probability of rejecting the null hypothesis when it is actually true (Type I error).
• p-value: The probability of obtaining results as extreme as or more extreme than the observed results if the null hypothesis is true.
• Statistical Power: The probability of correctly rejecting the null hypothesis when it is false (1 - Type II error).

Science and Technology

• Science: Focuses on understanding the natural world through inquiry and investigation.
• Technology: Application of scientific knowledge for practical purposes, often involving the creation of tools and techniques.
• Science advances understanding; technology applies that understanding to solve problems or create new tools.

Science is a systematic approach to understanding the natural world through observation, experimentation, and analysis. It operates on core principles such as objectivity, empiricism, and skepticism. The major branches include natural sciences, focusing on the physical world.