Why We Have Seasons

{
  "version": 1,
  "title": "Why We Have Seasons",
  "subtitle": "It is not about distance from the Sun. It is all about a tilt.",
  "topic": "What causes the seasons on Earth",
  "domain": "science",
  "emoji": "🌍",
  "kicker": "Earth science",
  "chips": [
    "Seasons",
    "Earth"
  ],
  "style": {
    "theme": "blueprint-lab",
    "header": []
  },
  "narration": {
    "voice": "F5",
    "speed": 0.95
  },
  "scenes": [
    {
      "kind": "intro",
      "say": [
        "Why is it hot in summer and cold in winter?",
        "Most people think the Earth gets closer to the Sun. The real answer is a surprise."
      ]
    },
    {
      "kind": "motion",
      "heading": "One trip around the Sun",
      "lead": "Let us start with the Earth's long journey.",
      "canvas": "wide",
      "shapes": [
        {
          "id": "orbit",
          "type": "path",
          "d": "M 34 30 A 46 22 0 1 1 126 30 A 46 22 0 1 1 34 30 Z",
          "stroke": "text",
          "strokeWidth": 0.35,
          "opacity": 0.5,
          "enter": "draw",
          "at": 0.2,
          "duration": 1.4
        },
        {
          "id": "sun",
          "type": "circle",
          "x": 80,
          "y": 30,
          "size": 14,
          "fill": "amber",
          "fill2": "orange",
          "glow": true,
          "loop": "pulse",
          "enter": "pop",
          "at": 0.5
        },
        {
          "id": "earth",
          "type": "circle",
          "x": 34,
          "y": 30,
          "size": 5,
          "fill": "sky",
          "fill2": "emerald",
          "glow": true,
          "enter": "pop",
          "at": "line1"
        },
        {
          "id": "axis",
          "type": "line",
          "x": 30,
          "y": 36,
          "x2": 38,
          "y2": 24,
          "stroke": "white",
          "strokeWidth": 0.5,
          "enter": "grow",
          "at": "line2"
        },
        {
          "id": "tilt",
          "type": "text",
          "text": "23.5°",
          "x": 22,
          "y": 18,
          "size": 5,
          "fill": "amber",
          "enter": "pop",
          "at": "line2"
        },
        {
          "id": "summer",
          "type": "text",
          "text": "Summer",
          "x": 80,
          "y": 5,
          "size": 5,
          "fill": "amber",
          "enter": "rise",
          "at": "line3"
        },
        {
          "id": "winter",
          "type": "text",
          "text": "Winter",
          "x": 80,
          "y": 56,
          "size": 5,
          "fill": "sky",
          "enter": "rise",
          "at": "line3",
          "delay": 0.4
        }
      ],
      "script": "tl.to(\"earth\", { motionPath: { path: \"orbit\" }, duration: 14, ease: \"none\", repeat: -1 }, \"line1\");",
      "lines": [
        {
          "say": "The Earth circles the Sun once a year, along a path that is almost round."
        },
        {
          "say": "But the Earth does not spin upright. It is tilted by about twenty-three degrees."
        },
        {
          "say": "So, during the year, each half of the planet leans towards the Sun for a while, and then away from it."
        }
      ]
    },
    {
      "kind": "worldmap",
      "heading": "Same month, opposite seasons",
      "lead": "This is why the two halves of the world have opposite seasons.",
      "places": [
        {
          "place": "Canada",
          "note": "December: winter",
          "tone": "sky",
          "say": "In December, Canada leans away from the Sun, so the days are short and cold."
        },
        {
          "place": "Australia",
          "note": "December: summer",
          "tone": "amber",
          "say": "At the same time, Australia leans towards the Sun, so it is hot and sunny."
        },
        {
          "place": "Argentina",
          "note": "December: summer",
          "tone": "orange",
          "say": "Argentina is also in the southern half of the world, so Christmas is a summer holiday there too."
        }
      ],
      "transition": "cube"
    },
    {
      "kind": "statement",
      "eyebrow": "The big idea",
      "text": "Seasons come from the **tilt** of the Earth, not from its distance to the Sun.",
      "icon": "🌗",
      "say": "So remember: seasons come from the tilt of the Earth, not from its distance to the Sun."
    }
  ]
}