Today’s physics news: Wednesday, 28 July 2010

String theorist Edward Witten gives prize lecture
The king of string theory visited London earlier this month to accept the Newton medal at the Institute of Physics. His full lecture is now online
Guardian 
 
Massive asteroid might hit Earth in 2182, warn scientists
It was first discovered in 1999 and is about 1,837 feet across. If an asteroid of this size hit the Earth it would cause widespread devastation and possible mass extinction.
Daily Mail 
 
First light for Solar Dynamics Observatory
‘Treasure trove’ of data reveals the anatomy and evolution of solar flares.
Nature 
 
Shields up! Force fields could protect Mars missions
Interplanetary adventurers must contend with deadly solar radiation – but the moon’s magnetic memories may hold the key to safe space flight
New Scientist