Great IdeasNature and science
Matter, atoms and elements
What things are made of.
The question
What is everything made of? Is matter made of tiny pieces, or of something smooth and continuous?
How the books answer
Oldest first. Each stop is our own short summary of what the author argued; follow the link to the rung for the whole lesson.
c. 360 BC
Plato, Timaeus and Critias
Plato imagines the four elements, earth, water, air and fire, as made of tiny geometric shapes: cubes, icosahedrons, octahedrons and pyramids, all built from triangles. Elements change into each other when their triangles break and recombine. It is mathematics shaping matter.
c. 350–322 BC
Aristotle, On Generation and Corruption
Aristotle rejects atoms and empty space. He teaches that the four elements are made of hot, cold, wet and dry in different pairs, and can turn into one another. His view was taught for nearly two thousand years.
c. 55 BC
Lucretius, On the Nature of Things (in the set: The Way Things Are)
Lucretius, following the Greek thinkers Democritus and Epicurus, teaches that everything is made of tiny atoms too small to see, moving in empty space. Nothing comes from nothing, and nothing is ever destroyed, only broken back into atoms. He gives clever everyday evidence, like clothes drying and rings wearing thin.
1620
Francis Bacon, Novum Organum
Bacon tests his new method on heat. Collecting many cases, he concludes that heat is a kind of motion of the tiny particles of bodies. It was a guess well ahead of its time.
“Heat is an expansive motion restrained, and striving to exert itself in the smaller particles.”
1789
Antoine Lavoisier, Elements of Chemistry
Lavoisier shows that in chemical reactions the total weight stays the same. He defines an element as any substance not yet broken down into simpler ones, and lists over thirty. Water, he showed, is not an element but hydrogen and oxygen combined.
1832–1855
Michael Faraday, Experimental Researches in Electricity
Faraday passes electric current through solutions and finds that the amount of a substance released depends exactly on the amount of electricity. The result hints that electricity and matter both come in definite units. He was careful, though, about claiming too much about atoms.
Go to the rung: Faraday: Experimental Researches in Electricity
1934; 1949
Niels Bohr, Atomic Theory and the Description of Nature (selections) and Discussion with Einstein on Epistemological Problems in Atomic Physics
Bohr pictures the atom as a tiny nucleus with electrons in fixed energy levels, jumping between them and giving off light of exact colors. His model explained the spectrum of hydrogen. He also wrote about how the strange behavior of atoms changes the way we describe nature.
Go to the rung: Bohr: Atomic Theory and the Discussion with Einstein
1958
Werner Heisenberg, Physics and Philosophy
Heisenberg, a founder of quantum mechanics, explains that at the smallest scale we can't know both exactly where a particle is and how it is moving. He compares the new physics to the old Greek debates, and suggests atoms are less like little stones and more like mathematical forms.
For young readers
Everything around you is made of matter: your chair, the air and even you! But what is matter made of?
Long ago, a Roman poet said everything is made of tiny pieces called atoms, too small to see. Here's a clue he used: a perfume bottle opened across the room can soon be smelled everywhere, because tiny bits travel through the air. Today scientists know atoms are real, and that they are made of even smaller parts.
Talk about it
- Lucretius said rings wear thin from fingers. What does that suggest?
- Lavoisier found weight stays the same in a reaction. If you burn a log, where does it go?
- Plato thought elements were shapes. Why do you think he liked that idea?
- How could people believe in atoms before anyone could see them?
Where else on the site
- How We Learned What Atoms Are
- Atoms Are Conserved
- Elements, Compounds and Mixtures
- Definite and Multiple Proportions
- The Bohr Model and Energy Levels
- The Uncertainty Principle
Every rung tagged with this idea:
These pages are our own short synthesis, written for families. They were inspired by Mortimer J. Adler's Syntopicon, the index of great ideas in volumes 1 and 2 of Great Books of the Western World, but the questions, summaries and groupings are ours, not the Syntopicon's. Short excerpts come from public-domain translations, credited where they appear.