Download The Universal Timekeepers by David J. Helfand (.MP3)
The Universal Timekeepers: Reconstructing History Atom by Atom by David J. Helfand / Narrated by Perry DanielsRequirements: .MP3 player, 290 mbOverview: Atoms are unfathomably tiny. It takes fifteen million trillion of them to make up a single poppy seed—give or take a few billion. And there’s hardly anything to them: atoms are more than 99.9999999999 […]