Light: A Fairy Tale [PDF + eBook]

When King John XV is crowned king of Amrath, no one is pleased — not the peasants throwing rotten vegetables, not his sensible steward Griselda, and not John himself, who would much rather be slaying dragons than governing. Then a mysterious sorceress slips into the throne room and hands him a candle, with a single warning: don't let it burn all the way down. John lights it anyway. Inside are the ghosts of five light mages — Albert Einstein, Snell, Thomas Young, Louis de Broglie, and James Clerk Maxwell — trapped by a witch and freeable only when the candle is fully burned. To free them without dying in the process, John has to become a light mage himself, learning to ride photons, refract through prisms, and pass through Young's double-slit experiment — while a rebellion gathers in the square below and a much older betrayal waits to be uncovered.

Written by Sarah Allen and illustrated by Vladimir Djekic, with cover design by Vik Charlie. Ages 9–12.

What's inside the book

• Four story chapters across 39 pages, with each of the trapped light mages introducing a different physics concept — Einstein on the speed of light, Snell on refraction, Young and de Broglie on the wave nature of light, and Maxwell on electromagnetic fields
• Several full-page color illustrations at pivotal story moments

Plus an extensive physics section

After the story, a dedicated physics section walks through the same concepts in clear, conversational prose. Diagrams illustrate each idea, and the actual equations are included for kids ready for algebra — though the author explicitly notes that the math can be skipped without losing the rest.

• The speed of light — including a "try this" with recommended MinutePhysics, Veritasium, and Vsauce videos on whether anything can exceed it
• Color, wavelength, and frequency — the visible spectrum, why colored objects appear the colors they do, and where infrared, microwaves, ultraviolet, and x-rays sit on the spectrum
• Reflection — including a classic mirror brainteaser (how tall does a mirror need to be to show your whole reflection?) worked through with the geometry
• Snell's Law of refraction — index of refraction, the vacuum-cleaner-on-carpet analogy for why light bends, and a "try this" with the PhET "Bending Light" simulation from the University of Colorado
• Electromagnetic waves — Young's double-slit experiment, the de Broglie equation, the Michelson-Morley experiment, and an introduction to Maxwell's equations and how light propagates through the vacuum of space
• Eight conceptual practice questions with a full answer key

What you'll get

• EPUB of the book (Kindle, Apple Books, Kobo)
• PDF of the book (for any device or for printing)
• Delivered by email immediately after purchase, plus available on your download page

Part of the Fairy Tale Physics series

Each book in the series is self-contained and can be read in any order, though readers of multiple books may notice the same physicists or recurring touches from kingdom to kingdom.

About the author

Sarah Allen tutored math and physics for twenty years before becoming a full-time fantasy writer. She has a physics degree from the University of Washington (graduated with college and departmental honors) and a master's in Cognition and Learning from Columbia. Her goal is to write the sort of physics books she would have wanted as a kid.

Ages 9–12 · 74 pages · Color illustrations