The Spacetime Metric

Young explorers · ages 8 to 12

Big questions about empty space.

Explore one idea at a time. Read the explanation, look closely at the illustration, then try the activity and explain what you noticed.

  1. A child climbs a five-colour ladder up the side of a giant open book toward the sunrise, beside a brass balance scale and a stream of paper boats.

    Lesson 1 · 6 min

    How Scientists Decide What Is True

    How do I know if a big science story is real?

  2. Two wooden toy sailing boats in a bathtub full of little waves, leaning toward each other while the water between them stays calm.

    Lesson 2 · 6 min

    Empty Space Is Not Empty

    If you took everything out of a box, what would be left inside?

  3. A child pushes a red cart full of pumpkins along a garden path while a glowing sea of tiny sparkles seems to push back on it.

    Lesson 3 · 6 min

    Where Does Heaviness Come From?

    Why is a loaded shopping cart so hard to get moving?

  4. Two children watch a marble roll around the deep dip a bowling ball makes in a big trampoline, with a wrinkled paper map lying in the grass.

    Lesson 4 · 6 min

    Bending Space and Riding a Wrinkle

    Could a ship travel very far without ever going fast?

  5. A child and a puppy sit at the end of a pier at dawn, looking at a calm glowing sea where ripples gather into little spinning whirlpools and round wave-bumps like tiny planets.

    Lesson 5 · 6 min

    Is Space a Kind of Sea?

    What if everything is a ripple on something we cannot see?

  6. A child in pyjamas and a striped cat look at a small sealed box glowing at its seams on a kitchen table, next to a lamp shining with no cord.

    Lesson 6 · 6 min

    Can You Get Energy From Nothing?

    If empty space is full of energy, can we plug into it?

  7. A laughing child on a beach holds a string tied to a huge grey boulder floating in the air like a balloon, with a leaping dolphin and gulls.

    Lesson 7 · 6 min

    Could a Ship Become Lighter?

    Could a craft make itself lighter and then move any way it likes?

  8. A workshop bench by a sea window with an old rolled drawing of a lens-shaped craft held flat by a mug and a magnifying glass.

    Lesson 8 · 6 min

    The Navy's Very Strange Patents

    Why did the United States Navy patent a spaceship?

  9. A child and a dog wrapped in a quilt on a farmhouse porch watch a glowing ball of lightning hover over a rain puddle during a night storm.

    Lesson 9 · 6 min

    Glowing Balls That Hold Themselves Together

    Can a glowing ball of hot gas really hold its own shape?

  10. A child holds a compass whose needle turns beside a tall coil of copper wire in a sunny garden, with soft ribbons of light circling the coil.

    Lesson 10 · 6 min

    The Field Hiding Behind the Fields

    How can an electron feel a magnet it never comes near?

  11. A closed book resting on a table, with one arrow pointing up from the book and one arrow pointing down from the same spot, both the same length.

    Lesson 11 · 6 min

    Why Doesn't the Book Fall?

    If gravity is pulling the book down, why does it just sit there?

  12. A child in oversized safety goggles peers into a big glass jar packed with shiny silver marbles, with tiny golden sparks flickering between them.

    Lesson 12 · 6 min

    Fusion Inside a Block of Metal

    Could you run the Sun's own reaction inside a lump of metal?

  13. A child on a hilltop at sunset lifts the last piece of a giant jigsaw puzzle showing a starry sky, a calm sea, a glowing box and a floating silver disc, with a dog and a kite nearby.

    Lesson 13 · 6 min

    Putting the Whole Puzzle Together

    If every piece worked, what could people actually build?

Grown-ups: read the activity together before starting and follow its supervision instructions. Chapter links offer a longer explanation to explore together.