  A critical discussion of the present status of the CERN experiments on charm
dynamics and hadron collective flow is given. We emphasize the importance of
the flow excitation function from 1 to 50 A$\cdot$GeV: here the hydrodynamic
model has predicted the collapse of the $v_1$-flow and of the $v_2$-flow at
$\sim 10$ A$\cdot$GeV; at 40 A$\cdot$GeV it has been recently observed by the
NA49 collaboration. Since hadronic rescattering models predict much larger flow
than observed at this energy we interpret this observation as potential
evidence for a first order phase transition at high baryon density $\rho_B$. A
detailed discussion of the collective flow as a barometer for the equation of
state (EoS) of hot dense matter at RHIC follows. Additionally, detailed
transport studies show that the away-side jet suppression can only partially
($<$ 50%) be due to hadronic rescattering. We, finally, propose upgrades and
second generation experiments at RHIC which inspect the first order phase
transition in the fragmentation region, i.e. at $\mu_B \approx 400$ MeV ($y
\approx 4-5$), where the collapse of the proton flow should be seen in analogy
to the 40 A$\cdot$GeV data. The study of Jet-Wake-riding potentials and Bow
shocks -- caused by jets in the QGP formed at RHIC -- can give further
information on the equation of state (EoS) and transport coefficients of the
Quark Gluon Plasma (QGP).
