In this essay we marshal evidence suggesting that Einstein gravity may be an
emergent phenomenon, one that is not ``fundamental'' but rather is an almost
automatic low-energy long-distance consequence of a wide class of theories.
Specifically, the emergence of a curved spacetime ``effective Lorentzian
geometry'' is a common generic result of linearizing a classical scalar field
theory around some non-trivial background. This explains why so many different
``analog models'' of general relativity have recently been developed based on
condensed matter physics; there is something more fundamental going on. Upon
quantizing the linearized fluctuations around this background geometry, the
one-loop effective action is guaranteed to contain a term proportional to the
Einstein--Hilbert action of general relativity, suggesting that while classical
physics is responsible for generating an ``effective geometry'', quantum
physics can be argued to induce an ``effective dynamics''. This physical
picture suggests that Einstein gravity is an emergent low-energy long-distance
phenomenon that is insensitive to the details of the high-energy short-distance
physics.Comment: 8 pages, Essay awarded an honorable mention in the year 2001 Gravity
Research Foundation essay competitio
