# Storm In A Teacup **Helen Czerski** | [[Foundations]]  --- > "The world is full of patterns, and understanding even one or two of these patterns is enough to explain an enormous amount about how our world works." Helen Czerski's gift is making physics feel inevitable rather than mysterious. She takes ordinary phenomena—popcorn popping, tea swirling, toast burning—and reveals the universal principles at work. These aren't party tricks. They're the same mechanisms that govern ocean currents, climate patterns, and why your phone battery dies faster in winter. > "Size matters. The physics that govern a bacterium are not the same as those that govern an elephant." **Size matters.** The physics of the very small is different from the physics of the very large. Surface tension dominates at small scales (why insects can walk on water). Gravity dominates at large scales (why elephants can't). Understanding *which forces dominate at which scales* is the key to seeing why things behave as they do. We live surrounded by physics. It's not abstract or distant—it's the reason your coffee cools, why fizzy drinks bubble, and how ships float. Once you see the patterns, the world becomes more comprehensible. --- ## Core Ideas ### [[Scale and Dominance]] The same substance behaves completely differently at different scales because different physical forces dominate. At small scales, surface tension dominates (water droplets form spheres, insects walk on ponds). Viscosity matters more than inertia (bacteria swim through water like we'd swim through honey). Heat transfers quickly (small animals lose body heat rapidly). At large scales, gravity dominates (planets are spherical due to their own gravity). Inertia matters more than viscosity (momentum carries you forward). Heat transfers slowly (oceans act as climate buffers). This explains why you can't scale up or down naively. A mouse scaled up to elephant size would overheat and collapse under its own weight. An elephant scaled down to mouse size would freeze to death. ### [[Thermodynamics and Entropy]] The second law of thermodynamics isn't just abstract physics—it's why coffee cools, why batteries run down, and why you can't un-burn toast. > "The second law of thermodynamics is the reason you can't un-burn toast or un-scramble an egg. Time has a direction." Heat flows from hot to cold—never the reverse (without work being done). Entropy increases: disorder naturally grows; order requires energy to maintain. Energy spreads out: concentrated energy (hot coffee) dissipates into surroundings until equilibrium. This is why perpetual motion machines don't exist and why you can't get more energy out of a system than you put in. The universe has a direction—toward greater disorder. ### [[Waves and Resonance]] Waves are everywhere: light waves, sound waves, water waves, seismic waves. They all share common patterns. Frequency and wavelength are inversely related (high pitch equals short wavelength). Resonance occurs when you push at natural frequency (opera singer shattering glass, bridges collapsing in wind). Interference creates patterns (noise-cancelling headphones, structural weak points). Understanding waves explains why microwave ovens work, why noise-cancelling headphones are possible, and why the Tacoma Narrows Bridge collapsed. ### [[Buoyancy and Density]] Archimedes' principle: objects displace their weight in fluid. If the displaced fluid weighs more than the object, it floats. Ships float because they displace more water than they weigh (hull shape matters). Hot air balloons rise because hot air is less dense than cold air. Ice floats because frozen water is less dense than liquid water (unusual property that makes life possible). This explains why steel ships float but steel balls sink, why submarines can control their depth, and why oceanic dead zones form. ### [[Phase Changes and Energy]] Water's unusual properties make Earth habitable. > "Water is weird. And that's why life on Earth is possible." Water has high heat capacity (oceans moderate climate by absorbing and releasing huge amounts of heat). It expands when frozen (ice floats, preventing lakes from freezing solid). It has high surface tension (enables capillary action—how trees pull water up). It's an excellent solvent (why it's the medium for life). Phase changes (solid/liquid/gas) involve enormous energy transfers without temperature change. This is why sweating cools you and why burns from steam are worse than from boiling water. --- ## Key Insights **Popcorn pops** because water inside the kernel turns to steam, building pressure until the hull explodes. **Toast browns** via Maillard reaction—sugars and amino acids recombine at high temperature. **Fizzy drinks bubble** because gas solubility decreases as pressure drops (opening the bottle) or temperature rises. **Kettles boil** more slowly at altitude because water boils at lower temperature when atmospheric pressure is lower. **Oceans are climate buffers** due to water's high heat capacity—they absorb summer heat and release it in winter. **Ocean currents** are driven by temperature and salinity differences (thermohaline circulation). **Weather systems** are heat engines, moving energy from warm tropics to cold poles. **The Gulf Stream** makes Western Europe habitable by carrying tropical heat northward. **Blue sky** occurs because air molecules scatter short wavelengths (blue) more than long wavelengths (red). **Red sunsets** happen because sunlight passes through more atmosphere, scattering away the blue. **Rainbows** form when light refracts and reflects inside water droplets. **Colour is a property of observers**, not objects—objects absorb some wavelengths and reflect others. **Coriolis effect** makes hurricanes spin (clockwise in Southern Hemisphere, anticlockwise in Northern). **Gyroscopes resist changes** in orientation, which is why bikes stay upright when moving. **Spinning objects store angular momentum**—changing their spin requires torque. **Electricity is electrons moving** through conductors—pushed by voltage, resisted by resistance. **Batteries store chemical energy** and convert it to electrical energy via redox reactions. **Magnetic fields** arise from moving charges (current in a wire creates magnetism). **Induction** means changing magnetic fields generate electric current (how generators work). --- ## Connects To - [[The Fifth Discipline]] - Both emphasise seeing patterns and interconnections; physics reveals universal patterns, systems thinking reveals structural patterns - [[Algorithms to Live By]] - Scale and dominance connects to computational complexity—problems that work at small scale break at large scale - [[Everything Is Predictable]] - Physical laws are deterministic; uncertainty arises from complexity and incomplete information - [[Antifragile]] - Thermodynamics explains why disorder increases; building order (antifragility) requires constant energy input --- ## Final Thought Physics isn't confined to labs or textbooks—it's in your kitchen, your garden, your daily commute. The same principles that make popcorn pop also drive ocean currents and star formation. Once you understand a few fundamental patterns—scale, entropy, waves, density—you have a lens for understanding an enormous range of phenomena. This is what scientific literacy looks like: not memorising formulas, but recognising patterns. **Scale determines behaviour.** The physics of small things is genuinely different from the physics of large things. Surface tension lets insects walk on water but is irrelevant for ships. Gravity shapes planets but barely affects molecules. Understanding which forces dominate at which scale is the key to prediction. The world is comprehensible. Complex phenomena emerge from simple rules applied at scale. You don't need to understand everything to understand *something*—and that something is often enough to see why the world works as it does. That's the promise of scientific thinking: patterns make the world navigable.