Posts tagged ‘john barrow’

May 12th, 2012

Symmetry in Physics

by Max Andrews

For every particle there is a corresponding symmetric particle.  Physics has a translational symmetry, which means that the laws and values of physics are the same at every location in the universe.  If an observer were to travel from one point to a much farther distant point the observer we see no change in the physics.  A broken symmetry introduces change—a non-absolute uniformity.  The breaking of symmetries creates complexity in the laws of nature in the outcome of laws.  There’s a symmetry and uniformity between the strong and weak nuclear forces, which have been unified as electromagnetism by James Clerk Maxwell.  A typical example of vital symmetry breaking is that which gives rise to the balance between matter and antimatter in the early universe.  However, there is an asymmetry between the quantum and the large (a la gravity). String theory is the attempt to unify all of physics.

May 10th, 2012

The Anthropic Principle

by Max Andrews

The anthropic principle takes two primary forms: the weak (WAP) and the strong (SAP).  The WAP is a reflective and happenstantial inquiry: The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirement that the universe be old enough for it to have already done so.[1]  The SAP is much more problematic: rather than considering just one universe we envisage an ensemble of possible universes—among which the fundamental constants of nature vary. Sentient beings must find themselves to be located in a universe where the constants of nature (in addition to the spatiotemporal location) are congenial.[2]