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Learning path · 19 parts

Planet Earth

The machinery of a working planet — the rock that moves beneath it, the air and ocean that carry its heat, and the carbon and radiation budgets that set its temperature.

About 3 hours of reading · 38 widgets

Start with Plate Tectonics
  1. Earth & Climate10 min

    Part 1: Plate Tectonics

    Why South America fits Africa, why Wegener was dismissed for half a century, and how magnetic stripes on the seafloor finally supplied the mechanism that turned continental drift into plate tectonics.

  2. Earth & Climate10 min

    Part 2: The Rock Cycle

    Rock is the everyday symbol of permanence, yet every rock is midway through a journey. Three families — igneous, sedimentary, metamorphic — endlessly transform into one another over deep geological time, driven by Earth's internal heat and by weathering at the surface, with no fixed one-way path.

  3. Earth & Climate10 min

    Part 3: Volcanoes: Why Some Ooze and Some Explode

    Why eruption style is set by a magma's silica and dissolved gas rather than luck, and why volcanoes cluster at plate boundaries and hotspots instead of appearing at random.

  4. Earth & Climate10 min

    Part 4: Earthquakes and Seismic Waves

    How a fault stores strain for centuries and lets go in seconds, why P waves arrive before S waves, and how the shadow that shear waves cast on the far side of the planet revealed a liquid outer core.

  5. Earth & Climate10 min

    Part 5: Earth's Magnetic Field

    Why the field is not a buried bar magnet but the churning output of a planet's molten iron heart — how the geodynamo generates it, why the magnetic poles wander and occasionally flip, and how the magnetosphere it throws up keeps the solar wind off the atmosphere.

  6. Earth & Climate10 min

    Part 6: Auroras: Why the Sky Glows at the Poles

    How solar-wind particles funneled to the poles by Earth's magnetic field excite oxygen and nitrogen high in the atmosphere, making it emit the green, red, and purple light of the aurora.

  7. Earth & Climate10 min

    Part 7: The Coriolis Effect: Curved Paths on a Spinning World

    Why moving air, water, and cannonballs curve on a rotating planet, why the effect scales with latitude, and why it has nothing to do with which way your sink drains.

  8. Earth & Climate10 min

    Part 8: The Seasons: It's the Tilt, Not the Distance

    Why seasons come from Earth's 23.4-degree axial tilt, not its distance from the Sun — how ray angle and day length flip the hemispheres into opposite seasons.

  9. Earth & Climate10 min

    Part 9: Why Weather Happens

    Differential heating, adiabatic lapse rates, and latent heat — how one energy imbalance builds thunderstorms, deserts, jet streams, and a hard two-week limit on forecasting.

  10. Earth & Climate10 min

    Part 10: Clouds and Rain: How Air Makes Water Appear

    Clouds form when rising air expands, cools to its dew point, and vapour condenses on tiny particles — not because warm air acts like a sponge that runs out of room.

  11. Earth & Climate10 min

    Part 11: Lightning: How a Storm Builds a Spark

    How a thunderstorm separates electric charge with updrafts and colliding ice until the air breaks down, and why the brilliant flash is a return stroke traveling upward.

  12. Earth & Climate10 min

    Part 12: Ocean Circulation

    Why the Gulf Stream is narrow and fast, what the Coriolis effect actually does (and does not do), and what oceanographers really think about an AMOC collapse.

  13. Earth & Climate10 min

    Part 13: El Niño: When the Pacific Flips

    El Niño is not a single storm but one warm phase of ENSO — a recurring ocean-atmosphere oscillation that redistributes the tropical Pacific's heat and rain worldwide.

  14. Earth & Climate10 min

    Part 14: Hurricanes: Nature's Heat Engines

    Why a hurricane is a heat engine, not a wind machine: warm-ocean evaporation and latent heat are the fuel, the Coriolis effect only organises the spin, and a warming ocean tilts the odds toward the most intense storms.

  15. Earth & Climate10 min

    Part 15: The Water Cycle

    Water is conserved and endlessly recycled through a handful of reservoirs of wildly different sizes. Residence time — reservoir divided by flux — explains why a molecule spends nine days in the air but three thousand years in the deep sea, and why a warming atmosphere runs the whole cycle faster.

  16. Earth & Climate10 min

    Part 16: The Ozone Layer

    What ozone is, how the Chapman cycle builds and destroys it while absorbing UV, how one chlorine atom from a CFC can eat tens of thousands of ozone molecules, and why the ozone hole is a different problem from global warming.

  17. Earth & Climate11 min

    Part 17: The Greenhouse Effect

    Sunlight comes in as visible light and leaves as infrared, and a handful of molecules are transparent to one and opaque to the other. That asymmetry sets the temperature of the planet.

  18. Earth & Climate10 min

    Part 18: The Carbon Cycle

    Photosynthesis and ocean exchange dwarf human emissions, yet the atmospheric stock is rising. The resolution is the difference between a balanced two-way flux and a small one-way one — and it is the whole story of the carbon cycle.

  19. Earth & Climate10 min

    Part 19: Ice Ages and Milankovitch Cycles

    Three slow wobbles in Earth's orbit redistribute sunlight across latitude and season without changing the total. Feedbacks turn that whisper into a hundred-metre swing in sea level — and the ice cores that recorded it hold one of climate science's most misread details.