Physics, Space and Earth Science
Physics describes matter, motion, energy, forces, waves, and the systems that shape the Earth and space. This hub connects concise reference guides to foundational ideas, everyday observations, and astronomy.
Core ideas
Start with motion and forces, then connect those ideas to gravity, collisions, and the movement of objects. Other guides explain waves, fields, energy flow, and the ways scientists build evidence from observations.

Space and Earth
Explore planetary distances and order, Earth’s interior, tides, and the physical systems that influence our surroundings. Each topic is an introduction; measurements and local conditions can change the details.
Guides in this cluster
Read: Newton's inertia
Read: Equation for inelastic collision
Read: What is mass and gravity
Read: Electromagnetic spectrum nm
Read: Mars approximate distance from the sun
Read: Fun facts about the outer core
Read: Why does the moon control tides
Read: Description of a wind turbine
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