Physical Science: Physics and Chemistry

• Physical science studies non-living systems, unlike life science.
• Physics, chemistry, geology, and astronomy are all included.
• Physical science aims to grasp the basic rules of the cosmos and its parts.
• Understanding natural events depends on observation, testing, and math models.
• Many technical and engineering breakthroughs are based on physical science.

Physics

• The basic parts of the cosmos, the forces between them, and the results of these forces are all topics covered.
• Physics is divided into classical mechanics, electromagnetism, thermodynamics, and quantum mechanics.
• Energy, momentum, force, and fields are key ideas.
• Physics underlies everything from how stars move to how subatomic particles act.

Chemistry

• Chemistry examines matter, its features, and how it evolves.
• The focus is on the makeup, structure, characteristics, and reactions of atoms, molecules, and compounds.
• Understanding chemical bonds, reactions, and stoichiometry is essential.
• Chemistry is key to creating new materials, medicines, and industrial methods.

Geology

• Geology studies Earth, its structure, makeup, processes, and history.
• It includes studying rocks, minerals, landforms, and the forces that shape Earth.
• Plate tectonics, volcanism, and erosion are key geological concepts.
• Geology sheds light on past climates, resources, and dangers.

Astronomy

• Astronomy studies celestial objects like stars, planets, galaxies, and the universe.
• It involves watching and studying electromagnetic radiation from space to learn about these objects' features and evolution.
• Cosmology, stellar evolution, and planetary science are major areas.
• Astronomy helps to understand place in the universe and its origins.

Big Bang Theory

• The Big Bang theory is the main model for the universe's origin.
• The universe started from an extremely hot, dense state around 13.8 billion years ago.
• Evidence includes the cosmic microwave background radiation, the large-scale structure, and the abundance of light elements.
• The early universe was hot enough for nuclear fusion, creating hydrogen, helium, and lithium.
• As the universe expanded and cooled, gravity formed galaxies, stars, and planets.

Evidence for the Big Bang Theory

• Cosmic Microwave Background (CMB) is the afterglow of the Big Bang, a uniform radiation throughout the universe.
• The CMB has a blackbody spectrum at about 2.7 Kelvin.
• Redshift of Distant Galaxies indicates they are moving away, with speed increasing with distance, supporting an expanding universe.
• Abundance of Light Elements: The amounts of hydrogen, helium, and lithium match predictions, as they were made in the early universe.
• Large-Scale Structure: The galaxy distribution shows a cosmic web, agreeing with Big Bang simulations.

Timeline of the Big Bang

• Planck Epoch (0 to 10^-43 seconds): The earliest period, where current physics breaks down; quantum effects and equal fundamental forces occur.
• Grand Unification Epoch (10^-43 to 10^-36 seconds): The strong force separates from the electroweak force.
• Inflationary Epoch (10^-36 to 10^-32 seconds): The universe expands quickly.
• Electroweak Epoch (10^-36 to 10^-12 seconds): The electroweak force splits into electromagnetic and weak forces.
• Quark Epoch (10^-12 to 10^-6 seconds): The universe contains a quark-gluon plasma.
• Hadron Epoch (10^-6 to 1 second): Quarks form hadrons like protons and neutrons.
• Lepton Epoch (1 second to 10 seconds): Leptons and antileptons are in equilibrium.
• Nucleosynthesis (3 minutes to 20 minutes): Protons and neutrons form light nuclei, mainly hydrogen and helium.
• Matter Domination (70,000 years): Matter density exceeds radiation density.
• Recombination (370,000 years): Electrons and nuclei form neutral atoms, making the universe transparent.
• Dark Ages: No starlight exists, with the universe filled with neutral hydrogen.
• Reionization: The first stars and galaxies emit radiation, reionizing hydrogen.
• Structure Formation: Gravity increases density, forming galaxies and clusters.
• Present: The universe continues to expand.

Open Questions and Challenges

• Dark Matter: Makes up 85% of universe matter, nature unknown.
• Dark Energy: Accelerates universe expansion, nature unknown.
• Inflation: Details of inflation still unclear.
• Singularity: The Big Bang starts from infinite density, hard to understand with current physics.
• Matter-Antimatter Asymmetry: The universe contains mostly matter, unexplained since equal amounts should have been created.

Overview of physical science, focusing on physics and chemistry. Explores core principles, the universe's constituents, mechanics, electromagnetism, and thermodynamics. Discusses the study of matter, its properties, and how it changes.