Every fact in the three light and colour lessons is listed here with where it comes from. The numbers in [brackets] on the lesson pages link to this list.
Wikipedia was not used as a source. Numbers are rounded (for example 9.8 m/sΒ² for Earth's gravity). The text was drafted with help from AI (Claude) and then checked against these sources. Corrections: hello@echoesof.science.
Simplifications to be aware of: the lessons for younger pupils say light 'bounces' off objects and that the sky is blue because blue light 'is scattered most'. Both are correct simplifications of reflection and of Rayleigh scattering. The 400β750 nm range for visible light is the textbook's rounded range; individual eyes vary slightly.
Type: Space agency, written for children
Explains that sunlight contains all the colours, that gases and particles in the air scatter blue light (shorter waves) more than red, and that at sunset the light crosses more air, so most blue is scattered away and reds and yellows remain.
Used in: Ages 10β11 (quiz); Ages 10β11 (text); Ages 15β16 (quiz); Ages 15β16 (text); Ages 6β7 (quiz); Ages 6β7 (text)
Type: Space agency
States that the colour of an object is the wavelengths of light it reflects, while all other wavelengths are absorbed, and lists how light can be transmitted, reflected, absorbed, refracted or scattered.
Used in: Ages 10β11 (quiz); Ages 10β11 (text); Ages 15β16 (quiz); Ages 15β16 (text)
Type: Peer-reviewed open textbook
Models light as travelling in straight lines called rays, which can change direction at a mirror or when passing into another material.
Used in: Ages 10β11 (text); Ages 15β16 (text); Ages 6β7 (experiment); Ages 6β7 (quiz); Ages 6β7 (text)
https://openstax.org/books/college-physics-2e/pages/25-1-the-ray-aspect-of-light
Type: Peer-reviewed open textbook
States that the angle of reflection equals the angle of incidence, and explains why a smooth mirror reflects at one angle while rough paper scatters light in all directions (so it can be seen from anywhere).
Used in: Ages 10β11 (quiz); Ages 10β11 (text); Ages 15β16 (experiment); Ages 15β16 (quiz); Ages 15β16 (text); Ages 6β7 (quiz); Ages 6β7 (text)
https://openstax.org/books/college-physics-ap-courses-2e/pages/25-2-the-law-of-reflection
Type: Peer-reviewed open textbook
White light is a mixture of all visible wavelengths. Dispersion spreads it into a spectrum because the refractive index depends on wavelength, so violet bends more than red. Rainbows form by refraction and reflection in raindrops.
Used in: Ages 10β11 (experiment); Ages 10β11 (quiz); Ages 10β11 (text); Ages 15β16 (quiz); Ages 15β16 (text); Ages 6β7 (text)
https://openstax.org/books/college-physics-2e/pages/25-5-dispersion-the-rainbow-and-prisms
Type: Peer-reviewed open textbook
Gives c = 3.00 Γ 10βΈ m/s, c = fΒ·Ξ», visible light between about 400 nm and 750 nm, red with the longest wavelength and lowest frequency, violet the shortest.
Used in: Ages 10β11 (text); Ages 15β16 (quiz); Ages 15β16 (text)
https://openstax.org/books/college-physics-2e/pages/24-3-the-electromagnetic-spectrum
Type: Space agency
States that light takes eight minutes to travel the 93 million miles (about 150 million km) from the Sun to Earth.
Used in: Ages 10β11 (quiz); Ages 10β11 (text); Ages 15β16 (quiz); Ages 15β16 (text)