Preface -- Part I. Gases, bubbles and surroundings -- Perfect coffee and oxygen cylinders: the ideal gas law -- Boats, balloons, and air bubbles: Archimedes' principle -- Air bubbles in the blood sample: better or worse oxygenation? Dalton's law and Fick's law -- Cold, sparkling drinks, and blood gas analysis: Henry's law -- Bubbles, tracheal tube cuffs, and reservoir bags: surface tension and Laplace's law -- Part II. Fluids in motion: masks, tubes, and hemodynamics -- The Venturi mask works like an airplane: Bernoulli's theorem -- From tubes and catheters to the basis of hemodynamics: the Hagen-Poiseuille equation -- Part III. Hemodynamic monitoring -- Toothpaste, sea deeps, and invasive pressure monitoring: Stevin's law and Pascal's principle -- Heat, cardiac output, and what is the future: laws of thermodynamics -- Part IV. Forces in action -- Doors, steering wheels, and central venous catheters: the moment of a force (torque) -- Friction, trigonometry, and Newton's laws: all about Trendelenburg position -- Part V. Inhalation anesthesia -- Why a vaporizer is not exactly a vaporizer and why it weighs so much: saturated vapor pressure and heat of vaporization -- Thermal expansion: train tracks, thermostats and, again, vaporizers -- The voice of xenon: origin and propagation of sound -- Part VI. Electromagnetic waves -- Light, air pollution and pulse oximetry: the Beer-Lambert law -- Cerebral oximetry and why the sky is blue: Rayleigh scattering -- Catch me if you can: X-ray, Compton scattering and the inverse square law -- Part VII. Now we exaggerate -- Activated clotting time and... A brief look at the theory of relativity.