physical science: Quick Facts

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Large Hadron Collider

Diagram showing Earth's axis of rotation tilted at about 23.5 degrees, illustrating precession as the axis traces a circular path over 26,000 years, shifting alignment from Polaris, the current North Star, to Vega. Labels indicate the plane of Earth's orbit and the changing orientation of the axis over time.

Diagram illustrating Ptolemy's equant model, showing a stationary Earth at the center with a planet moving in a small circle called an epicycle, which itself moves along a larger circle, the deferent. The equant point is marked off-center from Earth, and the positions of apogee and perigee are labeled. Small stars are scattered in the background.

Bronze bust of Epicurus with a full beard and draped clothing, displayed on a round inscribed base at the National Archaeological Museum of Naples.

Illustration showing Archimedes' principle: a 5 kg weight is weighed in air, then submerged in water, where it appears to weigh 2 kg; a separate container shows 2 kg of displaced water, demonstrating buoyant force.

Illustration of the Copernican heliocentric system showing the sun at the center with concentric orbits for Earth, other planets, and moons, labeled in French.

Nicolaus Copernicus

Nicolaus Copernicus: heliocentric system

Tycho Brahe's model of Saturn's motion

How we understood the universe throughout history

Kepler's revolutionary laws of planetary motion

How gravity works on Earth and in the universe

The discovery of light's wave-particle duality

Understanding John Dalton's atomic theory of matter

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Topics

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principles of physical science: Introduction

Key People

Joseph Priestley

Joseph Priestley

English clergyman and scientist

Jean-Baptiste Lamarck

Jean-Baptiste Lamarck

French biologist

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Sadi Carnot

French engineer and physicist

John William Strutt, 3rd Baron Rayleigh

Lord Rayleigh

British scientist

Joseph Henry

Joseph Henry

American physicist

illustration of Robert Hooke's law of elasticity of materials

Robert Hooke

British scientist

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Pierre Bouguer

French scientist

A short history of the Smithsonian Institution

James Smithson

British scientist

Guericke, engraving by C. Galle, 1649, after a portrait by Anselmus von Hulle

Otto von Guericke

Prussian physicist, engineer, and philosopher

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Gustave-Auguste Ferrié

French scientist and military officer

Gilbert, William

William Gilbert

English scientist

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Aleksandr Aleksandrovich Friedmann

Russian mathematician and scientist

Réaumur, detail of an engraving by J. Blanchon

René-Antoine Ferchault de Réaumur

French entomologist

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Saul Dushman

American chemist

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Francis Hauksbee, the Elder

English scientist

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Francis Hauksbee, the Younger

English scientist

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Ebenezer Kinnersley

American scientist

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Peter Guthrie Tait

Scottish mathematician and physicist

Michael Faraday (L) English physicist and chemist (electromagnetism) and John Frederic Daniell (R) British chemist and meteorologist who invented the Daniell cell.

Faces of Science