A properly serious scientist who's so serious he's known as the Astronomer Royal and has one eye smaller than the other because of decades of squinting through telescopes, has warned that (he imagines that) the Large Hadron Collider might bring about the end of the planet in a variety of exotic and terrifying ways.
These are the planet-ending disaster scenarios as foreseen by Martin Rees, AKA Baron Rees, AKA the Astronomer Royal, AKA a former President of the Royal Society, AKA a man who has a book called On The Future: Prospects for Humanity to sell.
The most quote-worthy section of his recently published book has been pulled out already, in which he warns that the earth could be sucked into an LHC-triggered black hole, or something even more exotic could happen involving science that might see us compressed uncomfortably close together. Rees explains that this could happen via the formation of hypothetical particles called strangelets, which he says: "...under some hypotheses a strangelet could, by contagion, convert anything else it encounters into a new form of matter, transforming the entire earth in a hyperdense sphere about one hundred metres across."
So we'd either all die or be very, very closely squeezed together. There's also the remote hypothetical possibility that the LHC could trigger a "phase transition" that would somehow rip the fabric of space, which would hopefully mean the end of everything too. In short, it might all be over soon thanks to science. [Telegraph]