Tom McCurdy said:
What would it mean if QG is correct and einsteins equations only work for low level energies, what would be the consequences
this is the big question around testing QG
Alejandro is right:
when people write papers about "what it would mean if" that is called
"phenomenology"
For us humans it would mean no discernable difference.
But there might be some difference that could be detected in
the arrival of a burst of gammarays from a billion lightyears away.
and this is constantly happening, so it is potentially a great source
of information.
so the phenomenologist (like Amelino, as arivero says) must
do some calculations to see what effects a QG model predicts,
and then tell the astronomers what to look for,
as a way of testing the model.
there was a conference in February this year called WS-2004 about
QG phenomenology. (the field is currently getting some attention
from astronomers, and some showed up)