The best of the rest from the Physics arXiv this week
Small amounts of radioactive material have turned up in rainwater in the Bay Area, say nuclear scientists
Cloud Girlfriend will use Facebook and other social networks as a vehicle to get real women to chat.
A new computer model of the way heat is emitted by various parts of the Pioneer spacecraft, and reflected off others, finally solves one of the biggest mysteries in astrophysics
Friends' opinions will affect search results, thanks to a feature inspired by Facebook.
If advanced civilisations have mined their asteroid belts, we should be able to see the evidence, argue astronomers
Google's chief economist says search saves us 3.75 minutes a day -- but compared to what?
Symmetry is intimately linked to conservation laws in the real Universe. Now physicists have worked out how to use the same approach in a virtual one
'Fuzzy hashing' was invented to flag spam emails, but has found application in everything from malware detection to genome sequence alignment
Bill Atkinson invented everything from the menu bar to hypercard--the program that inspired the first wiki.