  We show that there are significant conceptual differences between QM and QFT
which make it difficult to view the latter as just a relativistic extension of
the principles of QM. At the root of this is a fundamental distinction between
Born-localization in QM (which in the relativistic context changes its name to
Newton-Wigner localization) and modular localization which is the localization
underlying QFT, after one liberates it from its standard presentation in terms
of field coordinates. The first comes with a probability notion and projection
operators, whereas the latter describes causal propagation in QFT and leads to
thermal aspects of locally reduced finite energy states. The Born-Newton-Wigner
localization in QFT is only applicable asymptotically and the covariant
correlation between asymptotic in and out localization projectors is the basis
of the existence of an invariant scattering matrix. Taking these significant
differences serious has not only repercussions for the philosophy of science,
but also leads to a new structural properties as a consequence of vacuum
polarization: the area law for localization entropy near the the causal
localization horizon and a more realistic cutoff independent setting for the
cosmological vacuum energy density which is compatible with local covariance.
The article presents some observations about the interface between QFT in CST
and QG.
