When we first launched the Biophysics course in early 2026, it covered 12 core topics — enough for a solid introduction but far from comprehensive. Today we're releasing an expanded version with 38 chapters and 76 embedded video lectures drawn from university-level biophysics series. The course now rivals a full two-semester graduate sequence.
From 12 to 38: What's New?
The original course covered molecular forces, diffusion, membrane physics, and an introduction to neural biophysics. The expansion adds 26 new chapters grouped into six new parts, while the original chapters have been revised and deepened with additional derivations and figures.
Part I: Molecular Biophysics (Chapters 1–8)
The molecular section now includes dedicated chapters on van der Waals interactions (deriving the London dispersion force from perturbation theory), hydrogen bonding (electrostatic models, cooperativity in water), the hydrophobic effect (entropy-driven assembly, the iceberg model critique), and polymer physics (freely jointed chain, worm-like chain, persistence length, and the force-extension relation relevant to single-molecule experiments).
Part II: Membrane and Transport Physics (Chapters 9–14)
Beyond the original membrane chapter, we now cover lipid bilayer mechanics (bending modulus, Helfrich free energy, vesicle shape equations), the Goldman–Hodgkin–Katz equation for membrane potentials with multiple ion species, ion channel biophysics (single-channel conductance, gating kinetics from patch-clamp data, the Hodgkin–Huxley model derived from voltage-clamp experiments), and active transport (the Na+/K+ ATPase cycle, thermodynamic efficiency, and the Onsager reciprocal relations for coupled transport).
Part III: Molecular Motors (Chapters 15–19)
This entirely new section covers the physics of biological machines. We derive the force-velocity relation for kinesin using a two-state chemical kinetic model, analyze myosin and the sliding-filament theory of muscle contraction, discuss rotary motors (the bacterial flagellar motor and ATP synthase), and introduce the thermodynamics of molecular machines using stochastic energetics and Jarzynski's equality.
Part IV: Sensory Biophysics (Chapters 20–25)
How do organisms convert physical stimuli into neural signals? The new sensory biophysics section covers mechanotransduction in hearing (hair cell mechanics, tip-link gating, the traveling wave on the basilar membrane and the cochlear amplifier), phototransduction in vision (rhodopsin photochemistry, the cGMP cascade, adaptation and Weber's law), and chemoreception in olfaction (receptor binding kinetics, combinatorial coding, and the vibration theory controversy).
Part V: Cardiovascular and Respiratory Biophysics (Chapters 26–31)
This part applies fluid mechanics to biology. We derive Poiseuille flow in blood vessels, analyze pulsatile flow using the Womersley number, cover the Windkessel model of arterial compliance, and discuss the physics of heart valves and cardiac output. The respiratory chapters cover gas exchange (Fick's law applied to the alveolar membrane, the oxygen dissociation curve and Hill equation), lung mechanics (compliance, surfactant physics, and Laplace's law for alveolar stability), and the biophysics of ventilation.
Part VI: Computational Biophysics (Chapters 32–38)
The final part bridges physics and computation. Chapters cover molecular dynamics simulations (force fields, integration algorithms, thermostats), Monte Carlo methods in biophysics (Metropolis algorithm, replica exchange), coarse-grained models (elastic network models, Go models for protein folding), bioinformatics tools (sequence alignment, structure prediction with AlphaFold), and systems biology (genetic regulatory networks, Gillespie algorithm for stochastic simulation).
76 Embedded Video Lectures
Every chapter now includes two embedded video lectures from the Phys550 and Biophysics 401 series. The videos are curated playlists that align with each chapter's content — watch the lecture first for intuition, then read the chapter for the full mathematical treatment. Videos are embedded directly on the page, so you never leave the CoursesHub interface.
What Stayed the Same
The course remains completely free, with no login required. Each chapter includes structured data for Google, inline SVG diagrams, and a chapter rating system. The dark theme and responsive layout carry over from the original version.