From Ethics in Science and Environmental Politics, a special issue on science communication in a changing world. The first chapter from Nanotechnology for Dummies by Richard D. Booker and Earl Boysen. From Fermilab, a new clue to explain human existence? Stephen Hawking on how to build a time machine: All you need is a wormhole, the Large Hadron Collider or a rocket that goes really, really fast. Yes, but why do it? Figuring out a reason for the world's longest-running scientific experiment. Hello, Dolly: A conversation in a Dublin bar in 1987 proved crucial to Sir Ian Wilmut's research and led ultimately to the first clone of an adult animal. Mark Kingwell reviews The Ego Tunnel: The Science of the Mind and the Myth of the Self by Thomas Metzinger and Why Us? How Science Rediscovered the Mystery of Ourselves by James Le Fanu. Why does it take so long to add new elements to the periodic table? Shing-Tung Yau explains how he discovered the hidden dimensions of string theory. Aids denialism is estimated to have killed many thousands; Jon Cartwright asks if scientists should be held accountable, while Bruce Charlton defends his decision to publish the work of an Aids sceptic. Accommodationist scientists are afraid of antagonizing a religious mainstream America: That’s silly — in the end, the truth will out. Ben Goldacre tells Julian Baggini why he expects rigour in the reporting of science. Science 2.0 Pioneers: From open-access journals to research-review blogs, networked knowledge has made science more accessible to more people around the globe than we could have imagined 20 years ago.