|Courtesy of Boris Kulikov|
The Physics arXiv Blog
An alternative view of the best new ideas in science. About: http://tinyurl.com/p6ypk56
When Does The Universe Compute?The idea that every physical event is a computation has spread like wildfire through science. That may need to change now that physicists have worked out how to distinguish between systems that compute and those that don’t
One of the hot topics in computer science is unconventional computing. This is the exploitation of unusual or exotic systems to perform computations.
Examples are numerous. Perhaps the most advanced is quantum computation which exploits the strange laws of quantum mechanics to perform computation. But there are other more exotic approaches such as using DNA to perform millions of simple calculations in parallel or even using slime mould to solve mazes.
Indeed some scientists claim that every physical event is a computation. Others disagree saying that this simply redefines the notion of a physical process and is either wrong or trivial.
That leads to an interesting and important question. What does it mean for a physical system to compute? Can researchers decide objectively whether a physical system is computing or not?
Today, we get an answer thanks to the work of Clare Horsman at the University of Oxford in the UK and a few buddies. These guys say that a physical computation is the use of a physical system to predict the outcome of an abstract evolution. As such, it is closely related to, but crucially different from, the notion of theory and experiment .