  This article is a review of modern approaches to gravity that treat the
gravitational interaction as a type of gauge theory. The purpose of the article
is twofold. First, it is written in a colloquial style and is intended to be a
pedagogical introduction to the gauge approach to gravity. I begin with a
review of the Einstein-Cartan formulation of gravity, move on to the
Macdowell-Mansouri approach, then show how gravity can be viewed as the
symmetry broken phase of an (A)dS-gauge theory. This covers roughly the first
half of the article. Armed with these tools, the remainder of the article is
geared toward new insights and new lines of research that can be gained by
viewing gravity from this perspective. Drawing from familiar concepts from the
symmetry broken gauge theories of the standard model, we show how the
topological structure of the gauge group allows for an infinite class of new
solutions to the Einstein-Cartan field equations that can be thought of as
degenerate ground states of the theory. We argue that quantum mechanical
tunneling allows for transitions between the degenerate vacua. Generalizing the
tunneling process from a topological phase of the gauge theory to an arbitrary
geometry leads to a modern reformulation of the Hartle-Hawking "no boundary"
proposal.
