The name "Einstein" is synonymous with genius. A cultural icon of the 20th century, the mere mention of his name prompts many to quote his famous mass-energy equivalence formula, E=mc2
, whilst the photograph of him sticking out his tongue has become an instantly recognizable meme of the digital age. But what do we really know of the man behind the face and that equation; his home life, his dreams, his aspirations? To allow a glimpse into his private world, Princeton University and the Hebrew University of Jerusalem have now released the collected works from Einstein's early life in digital form online for anyone to read.
Quantum entanglement, one of the odder aspects of quantum theory, links the properties of particles even when they are separated by large distances. When a property of one of a pair of entangled particles is measured, the other "immediately" settles down into a state compatible with that measurement. So how fast is "immediately"? According to research by Prof. Juan Yin and colleagues at the University of Science and Technology of China in Shanghai, the lower limit
to the speed associated with entanglement dynamics – or "spooky action at a distance" – is at least 10,000 times faster than light.
Einstein said it couldn't be done. But more than one hundred years later physicists at the University of Texas at Austin have finally found a way to witness “Brownian motion”; the instantaneous velocity of tiny particles as they vibrate. The “equipartition theorem” states that a particle's kinetic energy, that due to motion, is determined only by its temperature and not its size or mass, and in 1907 Einstein proposed a test to observe the velocity of Brownian motion but gave up, saying the experiment would never be possible – not so.