If the Universe Is Teeming with Aliens . Where Is Everybody?
Presents a detailed discussion of the 50 most cogent and intriguing answers to Fermi's famous question, divided into three groups: Aliens are already here am... »

New Eyes on the Universe
Twelve Cosmic Mysteries and the Tools We Need to Solve Them »

Higcse Biology Module 2
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Evidence-based Social Work
Evidence-based Social Work »

Higcse Biology Module 3
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Symbolen
<p>Van de ampersand & het hekje tot smileys en de puntkomma; we gebruiken dagelijks talloze symbolen. Sommige symbolen zijn vooral praktisch, andere tekens h... »

Higcse Biology Module 4
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Out Of This World
Colliding Universes, Branes, Strings, and Other Wild Ideas of Modern Physics »

Measuring the Universe
This text on cosmological distance begins by explaining distance determinism on Earth and then climbs the rungs of the distance ladder to the most distant ob... »

If The Universe Is Teeming With Aliens ... Where Is Everybody?
Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life »