M-theory (sometimes called "the theory formerly known as superstrings") is a bold attempt at a theory of everything, solving the problem of the

quantum theory of gravity by merging all matter and interactions into a single theory in which the fundamental objects are not point particles, but are higher-dimensional objects such as loops of "superstring."

Hawking side-steps the issue: if space-time is a self-contained continuum without boundaries, as the

quantum theory of gravity implies, it is meaningless to talk about what happened at or before its origin (which would be a boundary).

2, have given rise to a new critical test of the

quantum theory of gravity, reported herein, namely an orientation dependent effect, which directly tests the modified Schrodinger equation which includes the effects of the dynamical space.

A shared property of all these theories is the holographic principle, that is, the idea that a

quantum theory of gravity has to be able to describe physics occurring within a volume by degrees of freedom that exist on the surface of that volume.

"This could be a key to understanding the forces of nature, including the

quantum theory of gravity." Strange as dark energy seems, Turner notes, "I guarantee you it's not going away."

Since we lack a full

quantum theory of gravity, however, the exact form of the stress-energy tensor above is nebulous, and so one can assume the value of [T.sup.0.sub.0] to represent some quantum mechanical distribution of matter [4].

As we move towards the next frontier of defining a

quantum theory of gravity, it is clear that they will continue to play a predominant role.

In a

quantum theory of gravity, it should be possible to derive the Bekenstein-Hawking formula linking a black hole's entropy, temperature, and area from more fundamental ideas.

Rather than considering a full

quantum theory of gravity, one can deal with effective theories of quantum gravity, which are promising approaches to implement quantum corrections to GR [3].