Newton published the Principia in 1687 and it took another 200 years before most people could afford to read it, let alone study it formally. Today, the same quality of physics instruction once reserved for MIT and Caltech students is free, online, and available tonight. The catch: there are hundreds of options, most of them mediocre.
This guide cuts through the noise. Whether you're starting from zero, brushing up on physics fundamentals before an engineering program, or going deep on a specific branch like optics or electromagnetism, the courses below are the ones worth your time.
What to Know Before Picking a Physics Course
Physics splits into two very different learning tracks depending on your math level, and choosing the wrong one wastes weeks.
Conceptual vs. Calculus-Based Physics
Conceptual physics uses algebra and intuition to explain how the world works — forces, energy, waves — without heavy mathematics. It's ideal for curious learners, pre-med students, and anyone who last took math in high school. Calculus-based physics is what engineers and physicists actually use. It's harder, more precise, and necessary if you're heading into a technical field.
If you're unsure which track fits, ask yourself: do you need to solve physics problems professionally, or do you want to understand physics deeply? The former needs calculus. The latter can often get there conceptually first and add math later.
What Free Actually Means on These Platforms
On Coursera and edX, "free" typically means you can audit lectures and readings at no cost. Graded assignments and the verified certificate usually require payment. For most learners, the audit track is enough — you get the knowledge, you just don't get a credential. If you need the certificate for a job application or academic portfolio, factor in the fee.
Top Physics Courses Worth Your Time
These are real courses from accredited institutions. Each one has been selected for clarity of instruction, completeness of content, and usefulness to a specific type of learner.
How Things Work: An Introduction to Physics
Taught by University of Virginia professor Louis Bloomfield, this Coursera course explains physics through everyday objects — why a ball curves, how a microwave heats food, what keeps a roller coaster on its track. It's genuinely one of the best introductions to physics available online because it teaches intuition before formulas. Ideal for complete beginners or anyone who wants to understand physics without being buried in equations.
Physics of Geometrical and Physical Optics
This Coursera course covers how light behaves — reflection, refraction, lenses, diffraction, and interference — with enough mathematical depth to be useful in engineering and medical imaging contexts. If you work in or around photonics, ophthalmology, or optical engineering, this fills a gap that most general physics courses skip entirely.
On-Ramp to AP Physics C: Mechanics
Designed as a bridge course on edX, this one prepares you for calculus-based mechanics — the version of physics that engineering programs actually test. It covers kinematics, Newton's laws, rotational motion, and energy with the mathematical rigor AP Physics C demands. Strong choice for high school students prepping for the AP exam or anyone who wants to confirm their algebra is solid before taking university-level physics.
Physics Fundamentals: Oscillations and Waves
Oscillations and waves underpin acoustics, optics, quantum mechanics, and electrical engineering. This edX course treats the topic thoroughly — simple harmonic motion, damping, resonance, wave propagation — with worked examples that make the math followable. A useful standalone module if you already have basic mechanics and want to fill a specific gap.
Physics Fundamentals: Electromagnetics
Electromagnetism is where most physics students hit a wall, because the concepts are abstract and the math (Maxwell's equations) is formidable. This edX course breaks it down methodically: electric fields, magnetic forces, circuits, and induction. It pairs naturally with the oscillations course above if you're working through a self-directed physics curriculum.
The Physics of Electronic Polymers
A niche but genuinely interesting edX course on how physics applies to organic semiconductors — the materials behind flexible electronics, solar cells, and OLEDs. Not for general physics learners, but if you're in materials science, chemistry, or applied physics, this is a rare course that connects fundamental physics to a cutting-edge application area.
How to Build a Physics Curriculum from Free Courses
The biggest mistake self-directed physics learners make is jumping between courses without a coherent sequence. Physics is cumulative — gaps in mechanics will haunt you in thermodynamics, and weak electromagnetism makes quantum mechanics incomprehensible.
Suggested Sequence for Beginners
- Start with How Things Work — builds intuition and confidence without math overload.
- Add Oscillations and Waves — expands on mechanics and introduces wave behavior, which appears everywhere in later physics.
- Move to Electromagnetics — the second major pillar of classical physics, and essential for understanding electronics, light, and beyond.
Suggested Sequence for AP or University Prep
- On-Ramp to AP Physics C: Mechanics — confirms your math readiness and covers classical mechanics rigorously.
- Physics Fundamentals: Electromagnetics — matches the second half of introductory university physics.
- Optics — a natural extension once you understand waves and electromagnetism.
For each course, don't just watch lectures. Work the problems. Physics is learned by doing, not by re-reading notes. If a concept isn't clicking, Khan Academy's physics section is a reliable free supplement for filling in mathematical gaps.
What Free Physics Courses Won't Give You
Being honest about limitations saves time. Free online physics courses are excellent for learning and understanding. They are not a substitute for a physics degree in most professional contexts.
Research physics roles at universities and national labs require a PhD. Engineering roles typically require an accredited degree with verified coursework. If your goal is a credential that opens professional doors, online certificates from individual courses won't carry the same weight as a degree — though they can supplement one effectively or help you place out of introductory coursework.
Where free courses genuinely deliver: self-directed learning, career pivots that benefit from physics knowledge (data science, finance, software engineering), academic preparation, and satisfying personal curiosity. For these goals, the courses above are as good as anything available at any price.
FAQ
Can I learn physics from scratch online for free?
Yes. Start with a conceptual course like How Things Work on Coursera, which assumes no prior physics knowledge. From there, you can move into more mathematical territory once you have the intuition. The sequence matters — don't start with electromagnetics if you haven't covered basic mechanics.
Do I need calculus to take these physics courses?
It depends on the course. How Things Work and the introductory optics course use minimal calculus. The AP Physics C On-Ramp assumes algebra and introduces calculus concepts. The electromagnetics course uses calculus throughout. Check each course's prerequisites before enrolling — most list them clearly on the course page.
Are Coursera and edX physics certificates worth anything?
For professional credentialing purposes, they carry limited weight compared to an accredited degree. For demonstrating initiative on a resume, supplementing existing credentials, or personal development tracking, they're useful. The real value is the knowledge — the certificate is secondary.
How long does it take to complete one of these courses?
Most of the courses listed here range from 4 to 12 weeks at a pace of 4-6 hours per week. Self-paced courses let you compress or extend that timeline. Realistically, plan for 2-3 months per course if you're working through it alongside a job or other studies.
What's the difference between classical physics and modern physics?
Classical physics covers mechanics, thermodynamics, electromagnetism, and optics — the physics that governs everyday scales and speeds. Modern physics covers quantum mechanics and relativity, which govern atomic scales and very high speeds. The free courses listed here are primarily classical, which is where anyone should start regardless of eventual interest. Quantum mechanics requires strong classical foundations.
Is physics useful for software engineering or data science?
Directly, less so. Indirectly, more than most people expect. Physics trains problem decomposition, mathematical modeling, and dimensional thinking — habits that transfer well to systems design, simulation, and algorithm analysis. Some areas of data science (signal processing, computer vision, financial modeling) use physics mathematics directly. A conceptual physics background also helps with scientific computing and any domain involving physical systems.
Bottom Line
If you want to understand how the physical world works, How Things Work on Coursera is the right starting point — it's accessible, well-taught, and builds genuine intuition without overwhelming you with formulas.
If you're preparing for university engineering physics or AP Physics C, begin with the On-Ramp to AP Physics C: Mechanics on edX, then move into the electromagnetics course.
If you have a specific application in mind — optics for engineering, waves for acoustics, polymers for materials science — pick the relevant specialist course and go deep. Physics rewards focus.
None of these courses require money to get started. Audit them, work the problems, and decide after the first two weeks whether the credential is worth the upgrade. Most learners find the knowledge is the point.