matter also date back thirty years when T.D. Lee proposed “vacuum engineering” [@Lee:ma]. It was then also realized by W. Greiner and collaborators [@Hofmann:by; @Stocker:bi; @Stocker:ci] that extended regions of dense nuclear matter can be formed in high energy interactions of heavy nuclei, and that the measurement of collective flow patterns will provide the novel barometric probes of the equation of state of ultra-dense matter. The hunt for the QGP and other phases of nuclear matter has been underway since that time using several generations of higher energy accelerators, BEVALAC, AGS, SPS, and now RHIC, and covering an impressive energy range $\sqrt{s}-2m_N=0.2-200$ AGeV. In three years, LHC is expected to start vacuum engineering at $5500$ AGeV.

The first conclusive evidence for (highly dissipative) collective nuclear flow was seen at the BEVALAC in 1984 [@Reisdorf:1997fx], and at AGS and SPS there after. However, the first conclusive evidence for nearly dissipation free collective flow obeying $P_{QCD}$ had to await RHIC. In these lectures, the discovery of the novel low dissipation elliptic flow pattern at RHIC is highlighted as the first of three lines of evidence for QGP production at RHIC. Together with two other convergent lines of evidence, jet quenching and the 