Title: Mawr a bach
Subtitle: sef sêr ac electronau.
Description: The book is about the physical sciences and was intended for young readers, being based on a series of radio lectures by the author. It discusses the basics of astronomy, stars, galaxies, and the Solar System. The possibility of life elsewhere in the Universe is considered. The book describes an imaginary journey to the Moon. Eclipses, meteorites and meteors are discussed. Atoms and molecules are considered.