Title: Controversial theory argues the entire universe is a neural network
Headings: Controversial theory argues the entire universe is a neural network
Controversial theory argues the entire universe is a neural network
Content: 'All that is needed is to find a physical phenomenon which cannot be described by neural networks. Unfortunately, [this] is easier said than done.' When considering the workings of the universe on a large scale, physicists use a particular set of theories as tools. These are 'classical mechanics' — built on Newton's laws of motion — and Einstein's theories of relativity, which explain the relationship between space and time, and how mass distorts the fabric of spacetime to create gravitational effects. To explain phenomena on the atomic and subatomic scales, however, physicists have found that the universe is better explained by so-called 'quantum mechanics'. In this theory, quantities like energy and momentum are restricted to having discrete, not continuous, values (known as 'quanta'), all objects have the properties of both particles and waves — and, finally, that measuring a system changes it. This last point, the essence of Heisenberg's 'uncertainty principle', means that certain linked properties — such as an object's position and velocity — cannot both be precisely known at the same time, bringing probabilities into play. While these theories explain the universe very well on their own scales, physicists have long struggled to reconcile them together into a universal theory — a challenge sometimes dubbed 'the problem of quantum gravity'. For the two theories to mesh, gravity — described by general relativity as the curving of spacetime by matter/energy — would likely need to be made up of quanta and therefore have its own elementary particle, the graviton. Unfortunately, the effects generated by a single graviton on matter would be extraordinarily weak — making theories of quantum gravity seemingly impossible to test and ultimately determine which, if any, are correct.