A scientific theory is:
— designed to explain certain kinds of phenomena
— defined by its postulates
— supported or disproved by its predictions.

Nature of Scientific Theories

• Big Bang Theory: The Three Pieces
  1. General Relativity applied to the Universe as a Whole
  2. Cosmological Observations of the 20th Century
  3. Particle Physics applied to the Early Universe
• Chemistry: Postulate and Predictions
  • The Basic Postulate of Chemistry is that the structure and interactions among atoms, electrons, ions, nuclei, and molecules are governed by:
    • the electrostatic force per Quantum Mechanics
    • the Laws of Thermodynamics
    • the Conservation of Mass for chemical reactions
• Climate Change: Theory, Proof, and Effects
  • Enhanced Greenhouse Effect
  • Proof that climate change is real
  • Predicted Effects
• Covid-19
  • Disease, Drugs, Tests, Vaccines, Virus
• Economic Topics
  • American Rescue Plan
  • Assessing Tax Legislation
  • Balance of Trade
  • Cryptocurrency
  • Do tax cuts grow the economy?
  • Economy under Republican and Democratic Presidents
  • Effective Tax Rate
  • Federal Reserve Economic Graphs
  • Supply and Demand
  • Tariffs
• Electromagnetism
  • Electromagnetism, the theory of the electromagnetic force, introduced the fundamental idea of a field into physics.
• Energy: Theory, History, Use
  • Energy is an abstract quantity whose total amount — the sum of all its forms — remains the same.
• Evolution: Theory, Trees, Predictions
  • The Theory of Evolution makes predictions using Phylogenetic Trees generated from the postulate of Common Descent and facts about species.
• Forensic Science
  • Forensic Science is the use of scientifically based methods for developing evidence relevant to a crime or civil wrong.
• General Relativity
  • General Relativity, Einstein’s theory of gravity, is “the most beautiful physical theory ever invented.” (Sean Carroll)
• Global Warming: Theory, Proof, and Effects
  • Enhanced Greenhouse Effect
  • Proof that global warming is real
  • Predicted Effects
• GPS and Relativity
  • The GPS system incorporates both Special and General Relativity. Otherwise it wouldn’t work.
• Immune System
  • Half the immune system is messy and makeshift, the other half organized and directed. Both are complicated.
• International System of Units (SI), Fundamentally Revised
  • “The definition of the SI units is established in terms of a set of seven defining constants. The complete system of units can be derived from the fixed values of these defining constants, expressed in the units of the SI.” (SI Brochure, 9th edition, 2019)
• Mendel’s Theory of Heredity
  • Gregor Mendel conducted experiments breeding 28,000 pea plants between 1856 and 1863. He then developed a simple, ingenious theory predicting his results.
• Newton’s Theory of Gravitation
  • The Principia is “not only Newton’s masterpiece but also the fundamental work for the whole of modern science.” (Britannica)
• Plate Tectonics
  • Plate Tectonics “represents a true scientific revolution, analogous in its consequences to quantum mechanics in physics or the discovery of the genetic code in biology.” (Britannica)
• Public Key Encryption
  • An example using life-size numbers.
• Scientific Models
  • A model is a simple representation of complex phenomena.
• Thermodynamics
  • Thermodynamics is the science of energy, heat, temperature, and work.
• Quantum Mechanics
  • Quantum Mechanics “has proved extraordinarily successful at predicting all of the observed behaviors of all physical systems under all circumstances.” (Britannica)
  • But at its heart is a mystery which, in Richard Feynman’s words, “we cannot make go away by ‘explaining’ how it works.”
• Special Relativity
  • Special Relativity is Einstein’s simple, counterintuitive theory that the speed of light is the same in every non-accelerating reference frame.
• Standard Model of Particle Physics
  • The Standard Model is the theory that quantum fields are the fundamental entities of the universe and particles their localized vibrations.