Deceptively simple
Is the long-standing Collatz conjecture finally solved? Proposed in 1937, it states that repeatedly applying two simple algebraic rules to any number will always eventually produce 1. It has been verified for numbers up to 5.76 x 1018. Now Gerhard Opfer of the University of Hamburg in Germany claims to have proved it true for all numbers.
Climate death threat
Several Australian climate scientists have been given extra security after receiving death threats. Plans to levy a tax on Australia’s most polluting companies from July 2012 are being opposed by those who claim the move will…
