Curious Kids: how do ripples form and why do they spread out across the water?

The simple experiment of throwing a rock into water actually reveals some fundamental rules of physics.

Why are water waves circular? - Quora

Articles for young people - Noticias, Investigaciones y Análisis - The Conversation - página 1

Water – News, Research and Analysis – The Conversation – page 13

Cryptographic Biorhythms - by Xianyang City Bureaucrat

Difference between ripples, waves and swell - The Natural Navigator

Light, Study, Properties & Uses - Lesson

Ripples Across SA New — Spirit of Woman

Aberystwyth University on The Conversation

Energy – Notícias, Pesquisa e Análise – The Conversation – página 15

HSNEF Ripples Youth Committee

Curious Kids: is light a wave or a particle?