Part of the Physics JourneyBetaJourneyOptics, Waves and Modern Physics: From Mirrors to the Nucleus
Ten chapters, from reflection and lenses to the nucleus. Every problem is solved in steps: draw the ray, write the equations with units, then solve, and each step is checked.
5,917,228+ learners enrolled
53 lessons53 challenges105 quiz questions
- Beginner friendly
Hands-on interactive lessons
Quizzes to test your knowledge
Free certificate of completion
Watch the physics move
Every lesson draws its situation, and the motion plays out on screen. Here are six from the course.
Refraction
A pulse of light enters glass and bends toward the normal.
Lenses
Rays from the tip of the arrow cross again at the tip of the image: a converging lens makes a real, inverted image.
Waves
A travelling wave carries its shape along while each point only moves up and down.
Superposition
Two pulses pass through each other, adding where they overlap, and come out unchanged.
Interference
Two sources make ripples that add where crests meet and cancel along the quiet lines.
The Bohr atom
In the Bohr model the electron circles the nucleus only on certain orbits, each with its own energy.
Syllabus
This section is part of the Physics Journey. The full syllabus has more sections: click any preview below to view it on the Journey page.
- Section 1Mechanics94 lessons
- Section 2Electricity and Magnetism51 lessons
Section 3
Optics, Waves and Modern Physics
Start sectionStartLight and matter from zero: reflection, refraction and lenses, waves and interference, light as a wave through slits and gratings, photons and the photoelectric effect, the Bohr atom, and the nucleus: radioactive decay, half-life and binding energy.Reflection and Refraction
7 lessons1320Plane Mirrors
4 lessons79Thin Lenses
6 lessons1114Mechanical Waves
7 lessons1315The Ripple Tank
4 lessons76Light as a Wave
5 lessons98Photons
6 lessons1110The Bohr Atom
4 lessons78The Nucleus
6 lessons119Nuclear Energy
4 lessons76
Learn by Solving
Solve every problem the way physicists do: choose your axes, draw the forces, write the equations with units, and the board checks each step.
Draw every force on the body, pick your axes, then write Newton's second law along them.
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Promotion zoneEvery way to learn
Read, listen, test yourself, ask the AI about your own steps, or look up anything you've already covered. Every lesson meets you where you are.
A scalar is a size only, like a mass of 3 kg or a time of 4 s. A vector has a size and a direction.
A force is a push or a pull, measured in newtons: a push of 50 N to the right is a vector.
A vector is drawn as an arrow. Its length shows the size, and the arrow points in its direction.
Earn a Certificate
Earn a certificate when you complete a section. Add it to your LinkedIn profile to show how far your physics has come.
Certificate of CompletionPhysics Mechanics
Add to LinkedInWhy learn optics, waves and modern physics with Coddy
- Angles measured from the normal. Light at a surface is measured from the normal, and measuring from the surface instead is named as the mistake it is.
- Units are part of the answer. Wavelengths in nanometres, energies in electronvolts: a missing or unconverted unit is a wrong answer, as on an exam.
- Light and waves that move. Pulses, ripples and rays are drawn and animated, so every number has a picture.
- Modern physics from the numbers. Photon energy, the Bohr levels, half-life and binding energy are solved like everything else: in steps, with units.
Frequently asked questions about optics, waves and modern physics
What does the optics, waves and modern physics section cover?
Reflection and refraction, plane mirrors, thin lenses, mechanical waves, the ripple tank, light as a wave through slits and gratings, photons and the photoelectric effect, the Bohr atom, radioactive decay and half-life, and nuclear binding energy.
What is Snell's law?
n₁ sin θ₁ = n₂ sin θ₂. When light passes from one material into another, its angle from the normal changes by an amount set by the two refractive indices. Going into glass, the ray bends toward the normal.
What is the difference between a real and a virtual image?
A real image forms where light rays actually cross, so a screen can show it. A virtual image is where rays only seem to come from, like your reflection in a mirror, and no screen can show it.
What is the photoelectric effect?
Light shining on a metal can knock electrons out of it, but only if each photon carries enough energy. Brighter light of too low a frequency frees none, which is how Einstein showed that light comes in photons.
How long is the optics, waves and modern physics section?
Ten chapters and 53 lessons, each a few minutes long. Finishing it earns a free, verifiable certificate.
Do I get a Optics, Waves and Modern Physics certificate when I finish?
Yes. When you complete the Optics, Waves and Modern Physics course you receive a free certificate of completion that you can share on LinkedIn or add to your resume.
